.auth-page{min-height:100dvh;display:grid;place-items:center;padding:24px;background:var(--paper, #f4f3f0)}.auth-card{width:min(100%,420px)}.auth-card h1{color:var(--accent, #7b2435)}.auth-card form,.auth-card label{display:grid;gap:10px}.auth-card form{gap:18px;margin:24px 0}.auth-card input{width:100%;box-sizing:border-box;padding:12px;background:transparent;border:1px solid #b6aba8;border-radius:8px;color:inherit}.auth-card small{line-height:1.6;opacity:.75}.auth-card [role=alert]{color:var(--accent, #7b2435)}@font-face{font-family:Folitor Poem Xiaxing;src:url(/loading/fonts/slidexiaxing-poem-4p.woff2) format("woff2");font-style:normal;font-weight:400;font-display:block}.poem-loading{--poem-seal-red: #9e4528;position:fixed;top:0;right:0;bottom:0;left:0;z-index:2147483000;overflow:hidden;isolation:isolate;color:var(--ink);background-color:var(--paper);background-image:var(--paper-glow),var(--paper-img);background-repeat:no-repeat,repeat,repeat;background-attachment:fixed,fixed,fixed;background-size:100% 100%,var(--paper-size),var(--paper-size);opacity:1;transition:opacity .35s ease-out;touch-action:none}.poem-loading[data-lifting=true]{opacity:0}.poem-loading[data-lifting=false]{transition:none}.poem-loading__stage{position:absolute;top:50%;left:50%;transform-origin:center;mix-blend-mode:multiply;pointer-events:none;-webkit-user-select:none;-moz-user-select:none;user-select:none}.poem-loading__watercolor{position:absolute;mix-blend-mode:multiply}.poem-loading__watercolor video,.poem-loading__watercolor img{position:absolute;top:0;right:0;bottom:0;left:0;display:block;width:100%;height:100%;max-width:none;-o-object-fit:fill;object-fit:fill;background:transparent;mix-blend-mode:multiply;opacity:0}.poem-loading__text{position:absolute;z-index:1;color:var(--ink);font-family:Folitor Poem Xiaxing,KaiTi,STKaiti,serif;font-weight:400;font-style:normal;font-synthesis:none}.poem-loading__character{--ink-front: 0;--ink-start: .2em;--ink-travel: 1.6em;--ink-feather: .16em;position:absolute;display:block;box-sizing:content-box;padding:.35em;overflow:visible;text-align:left;line-height:1;letter-spacing:0;white-space:pre;opacity:0;-webkit-mask-image:var(--ink-mask, linear-gradient(168deg, #000 calc(var(--ink-start) + var(--ink-front) * var(--ink-travel) - var(--ink-feather)), transparent calc(var(--ink-start) + var(--ink-front) * var(--ink-travel) + var(--ink-feather))));mask-image:var(--ink-mask, linear-gradient(168deg, #000 calc(var(--ink-start) + var(--ink-front) * var(--ink-travel) - var(--ink-feather)), transparent calc(var(--ink-start) + var(--ink-front) * var(--ink-travel) + var(--ink-feather))));-webkit-mask-size:100% 100%;mask-size:100% 100%;-webkit-mask-position:center;mask-position:center;-webkit-mask-repeat:no-repeat;mask-repeat:no-repeat}.poem-loading__glyph{display:block;overflow:visible;transform:translate(var(--ink-x, 0px),var(--ink-y, 0px))}.poem-loading__seal{position:absolute;display:block;max-width:none;opacity:0;transform:scale(1.05);transform-origin:center;mix-blend-mode:multiply}.poem-loading__progress{position:absolute;inset:0 0 auto;height:3px}.poem-loading__progress-fill{position:relative;width:100%;height:100%;background:var(--poem-seal-red);transform:scaleX(0);transform-origin:left center}.poem-loading__progress-fill:after{content:"";position:absolute;top:0;right:0;width:70px;height:3px;box-shadow:0 0 7px 1px color-mix(in srgb,var(--poem-seal-red) 40%,transparent)}.poem-loading__percentage{position:absolute;top:max(12px,env(safe-area-inset-top));right:max(18px,env(safe-area-inset-right));color:color-mix(in srgb,var(--ink) 55%,transparent);font-family:var(--sans, sans-serif);font-size:12px;font-weight:400;line-height:1.5;font-variant-numeric:tabular-nums}:root[data-theme=dark] .poem-loading{--poem-seal-red: #b4644a}:root[data-theme=dark] .poem-loading__stage,:root[data-theme=dark] .poem-loading__watercolor,:root[data-theme=dark] .poem-loading__watercolor video,:root[data-theme=dark] .poem-loading__watercolor img,:root[data-theme=dark] .poem-loading__seal{mix-blend-mode:normal}:root[data-theme=dark] .poem-loading__watercolor[data-ground=white] video,:root[data-theme=dark] .poem-loading__watercolor[data-ground=white] img{filter:url(#poem-loading-white-key)}:root[data-theme=dark] .poem-loading__watercolor[data-ground=full-bleed]{-webkit-mask-image:linear-gradient(to right,transparent 2%,#000 11%,#000 89%,transparent 98%),linear-gradient(to bottom,transparent 2%,#000 10%,#000 90%,transparent 98%);mask-image:linear-gradient(to right,transparent 2%,#000 11%,#000 89%,transparent 98%),linear-gradient(to bottom,transparent 2%,#000 10%,#000 90%,transparent 98%);-webkit-mask-composite:source-in;mask-composite:intersect}:root[data-theme=dark] .poem-loading__watercolor[data-ground=full-bleed] video,:root[data-theme=dark] .poem-loading__watercolor[data-ground=full-bleed] img{top:6px;right:6px;bottom:6px;left:6px;width:calc(100% - 12px);height:calc(100% - 12px);filter:brightness(.74) saturate(.9)}:root[data-theme=dark] .poem-loading__seal{filter:brightness(.85) saturate(.9)}.poem-loading__filters{position:absolute;width:0;height:0;overflow:hidden;pointer-events:none}.poem-loading__announcement{position:absolute;width:1px;height:1px;overflow:hidden;clip-path:inset(50%);white-space:nowrap}[data-sr=pending]{opacity:0;translate:0 6px}[data-sr=in]{transition:opacity .32s cubic-bezier(.22,.61,.36,1) var(--sr-delay, 0ms),translate .32s cubic-bezier(.22,.61,.36,1) var(--sr-delay, 0ms)!important}@font-face{font-family:"Instrument Serif";src:url(/assets/InstrumentSerif-Regular-BjwVvGU6.ttf) format("truetype");font-style:normal;font-weight:400;font-display:swap}@font-face{font-family:"Instrument Serif";src:url(/assets/InstrumentSerif-Italic-BIypviHG.ttf) format("truetype");font-style:italic;font-weight:400;font-display:swap}:root{--paper: #f4f3f0;--paper-img: url(/assets/paper-light-x8nKOkqJ.png);--paper-glow-light: radial-gradient(ellipse 38% 31% at 44% 16%, rgb(255 255 255 / .32), transparent 72%);--paper-glow: var(--paper-glow-light);--paper-size: 720px 720px;--paper-deep: #ebe9e4;--raise: rgba(255, 255, 255, .62);--hover: rgba(43, 41, 38, .04);--hover-warm: rgba(158, 110, 60, .055);--sel-warm: rgba(158, 110, 60, .085);--sel-line: rgba(43, 41, 38, .22);--hair: rgba(43, 41, 38, .1);--hair-strong: rgba(43, 41, 38, .18);--surf-1: rgba(255, 255, 255, .42);--surf-2: rgba(255, 255, 255, .62);--surf-3: rgba(255, 255, 255, .78);--overlay-surface: var(--paper);--popover-surface: color-mix(in srgb, #fff 78%, var(--paper));--z-popover: 300;--dialog-title-size: 18px;--dialog-title-weight: 600;--dialog-body-size: 14px;--dialog-meta-size: 12px;--dialog-label-size: 13px;--dialog-control-size: 14px;--dialog-padding: 24px;--dialog-gap: 16px;--dialog-section-gap: 20px;--dialog-control-height: 38px;--dialog-line-height: 1.5;--dialog-muted: var(--color-muted);--ink: #2b2926;--ink-2: #55514b;--ink-3: #6a655d;--prose-ink: #34312d;--label: #8593a3;--label-ink: #52606f;--accent: #9e4528;--accent-soft: rgba(158, 69, 40, .07);--accent-wash: color-mix(in srgb, var(--accent) 9%, transparent);--ok: #4a6646;--warn: #8a5a1c;--focus-ring: #52606f;--bubble: #3a3733;--bubble-ink: #f4f1ea;--mark: color-mix(in srgb, #f4b8ce 52%, var(--paper));--strong-band: color-mix(in srgb, #9e4528 20%, transparent);--hl-bg: color-mix(in srgb, #f4b8ce 30%, transparent);--sel-bg: color-mix(in srgb, #f4b8ce 40%, transparent);--prose-selection: rgba(255, 230, 0, .4);--reader-mark-fill: color-mix(in srgb, #f4b8ce 34%, transparent);--reader-mark-line: var(--accent);--ask-bg: #22201d;--ask-ink: #f1ece3;--ask-tag: #d9b47e;--ask-line: transparent;--callout-note-bg: #fbf1e6;--callout-note-line: #b9835a;--callout-note-ink: #7a4a2a;--callout-tip-bg: #eef1ea;--callout-tip-line: #7e9a78;--callout-tip-ink: #3f5a3b;--callout-warn-bg: #f7eae5;--callout-warn-line: #b9735c;--callout-warn-ink: #8a3b22;--code-bg: #f4f0e8;--code-ink: #2b2926;--code-kw: #7a4a2a;--code-str: #4e5f72;--code-cm: #6a655d;--fig-bg: rgba(255, 255, 255, .5);--x-shadow: 0 14px 36px rgba(43, 36, 28, .1), 0 1px 3px rgba(43, 36, 28, .06);--x-scrim: rgba(38, 34, 30, .34);--serif: var(--font-serif);--sans: var(--font-sans);--r-sm: 8px;--r-md: 12px;--ease: cubic-bezier(.2, .7, .2, 1);--ease-out-strong: cubic-bezier(.23, 1, .32, 1);--dur-1: .12s;--dur-2: .2s;--bg: var(--paper);--fg: var(--ink);--border: var(--hair)}:root[data-theme=dark]{--paper: #21201e;--paper-glow: none;--paper-img: linear-gradient(rgb(33 32 30 / 55%), rgb(33 32 30 / 55%)), url(/assets/paper-dark-BbmPUdqh.png);--paper-deep: #1a1918;--raise: rgba(255, 248, 236, .06);--hover: rgba(255, 250, 240, .035);--hover-warm: rgba(255, 236, 210, .045);--sel-warm: rgba(255, 236, 210, .075);--sel-line: rgba(236, 232, 225, .3);--hair: rgba(236, 232, 225, .16);--hair-strong: rgba(236, 232, 225, .26);--surf-1: #282624;--surf-2: #2e2c29;--surf-3: #363330;--overlay-surface: var(--surf-2);--popover-surface: var(--surf-3);--ink: #ece8e1;--ink-2: #bdb7ad;--ink-3: #a39d93;--prose-ink: #e2ddd5;--label: #8796a8;--label-ink: #9aa8b8;--accent: #c4917a;--accent-soft: rgba(196, 145, 122, .12);--accent-wash: color-mix(in srgb, var(--accent) 12%, transparent);--ok: #93ac8c;--warn: #cda46e;--focus-ring: #9aa8b8;--bubble: #3b3935;--bubble-ink: #f1ede6;--mark: color-mix(in srgb, #e891b0 42%, transparent);--strong-band: color-mix(in srgb, #c8734f 38%, transparent);--hl-bg: color-mix(in srgb, #e891b0 28%, transparent);--sel-bg: color-mix(in srgb, #e891b0 36%, transparent);--prose-selection: rgba(255, 225, 0, .32);--reader-mark-fill: rgba(110, 150, 220, .26);--reader-mark-line: #8fb3ea;--ask-bg: #322f2b;--ask-ink: #f1ece3;--ask-tag: #d9b47e;--ask-line: rgba(236, 232, 225, .16);--callout-note-bg: rgba(200, 150, 100, .09);--callout-note-line: #b98b66;--callout-note-ink: #d8b08e;--callout-tip-bg: rgba(143, 175, 136, .1);--callout-tip-line: #7e9a78;--callout-tip-ink: #a9c4a2;--callout-warn-bg: rgba(196, 145, 122, .1);--callout-warn-line: #b9735c;--callout-warn-ink: #dda48e;--code-bg: #2a2826;--code-ink: #e6e1d9;--code-kw: #d9a57e;--code-str: #a6b6c8;--code-cm: #a39d93;--fig-bg: rgba(255, 250, 240, .035);--x-shadow: 0 0 0 1px rgba(236, 232, 225, .1);--x-scrim: rgba(8, 7, 6, .58)}@media(prefers-reduced-motion:reduce){:root{--dur-1: 0ms;--dur-2: 0ms}}:root{color-scheme:light;--color-bg: var(--paper);--color-paper-deep: var(--paper-deep);--color-surface: var(--paper);--color-surface-raised: color-mix(in srgb, #fff 45%, var(--paper));--color-rail: transparent;--color-border: var(--hair);--color-hairline: var(--hair);--color-text: var(--ink);--color-ink-soft: var(--ink-2);--color-muted: var(--ink-3);--color-primary: var(--ink);--color-primary-hover: color-mix(in srgb, var(--ink) 88%, var(--paper));--color-on-primary: var(--paper);--color-accent: var(--accent);--color-accent-soft: var(--accent-soft);--color-accent-border: color-mix(in srgb, var(--accent) 40%, transparent);--color-success: var(--ok);--color-danger: #c55a3d;--color-focus: var(--focus-ring);--font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;--font-serif: "Playfair Display", "Instrument Serif", "Songti SC", "STSong", "Noto Serif SC", "Source Han Serif SC", "Noto Serif CJK SC", Georgia, serif;--font-display: "Songti SC", "STSong", "Noto Serif SC", "Source Han Serif SC", "Noto Serif CJK SC", Georgia, serif;--font-num: var(--font-sans);--font-mono: "SF Mono", "JetBrains Mono", "Fira Code", ui-monospace, monospace;--text-body: 16px;--text-meta: 12px;--text-title: 30px;--text-section: 16px;--text-button: 13px;--text-tab: 13px;--text-nav: 12px;--space-1: 4px;--space-2: 8px;--space-3: 12px;--space-4: 16px;--space-6: 24px;--space-8: 32px;--space-12: 48px;--radius-sm: var(--r-sm);--radius-md: var(--r-md);--radius-lg: 16px;--radius-xl: 18px;--radius-card: 14px;--radius-control: 12px;--shadow-card: none;--rail-width: 90px;--page-width: 1120px;--mindmap-bg: transparent;--mindmap-outline-bg: var(--color-surface);--mindmap-border: var(--color-hairline);--mindmap-ink: var(--color-text);--mindmap-outline-ink: var(--color-ink-soft);--mindmap-selection: var(--sel-warm);--library-complete-cover: #e6e4ec;--library-green: #5b8078;--library-red: #b95b3f;--library-olive: #76704b;--library-blue: #53627b;--library-violet: #686180;--library-amber: #a5825e;--library-due-bg: #fceee7;--explore-copy-size: 14px;--explore-dialog-copy-size: 13.5px;--explore-promo-bg: #fbfaf6;--explore-green: #065f46;--explore-green-edge: #00a575;--explore-purchased-bg: #edfcf3;--explore-gold: #d4a574;--explore-bundle-bg: #fffaec;--explore-gift-bg: #fffcef;--explore-gold-border: #f2ddc4;--explore-mini-bg: #fffdf9;--explore-backdrop: rgb(28 25 23 / 50%);--explore-envelope-paper: #f3efe6;--explore-envelope-fold: #e5dfd5;--explore-envelope-shadow: #bdb7ae;--course-detail-border: var(--color-hairline);--course-detail-chip: var(--color-paper-deep);--course-detail-secondary: var(--color-ink-soft);--course-detail-meta: #b7b3af;--course-detail-purchased: #10b981;--shelf-heading: var(--color-text);--shelf-secondary: var(--color-ink-soft);--shelf-icon-bg: #eceae7;--shelf-icon-ink: #b7b3af;--shelf-cover-epub: #e8e7df;--shelf-cover-pdf: #e6e4ec;--me-gold: #d4a574;--me-button-ink: #292724;--me-secondary: #78716c;--me-navigation-muted: #57534e;--me-danger: #ef4444;--me-faint: #b7b3af;--me-placeholder: #a8adb4;--me-switch: #d6d3d1;--me-selected-bg: var(--sel-warm);--me-selected-border: var(--sel-line);--fp-learn: #7f93a8;--fp-master: #7e9a78;--fp-review: #b07a5a;--fp-peach: #fdf6ee;--fp-peach-border: #f4e2cf;--fp-day-active: #fffbeb;--fp-session: #f59e0b;--fp-mastered: #10b981;--fp-reviewed: #6366f1;--fp-orange: #c98143;--fp-review-red: #c65336;--fp-review-badge: #fbece4;--fp-review-border: #f4d1c3;--review-amber: #8a5a1c;--review-amber-soft: #f5e9d4;--review-critical-soft: #f8e8e2;--review-solid-soft: #e8efe4;--learn-header: var(--color-surface);--learn-sidebar: var(--color-paper-deep);--learn-notes: var(--color-surface);--learn-notes-inset: 19.5px;--learn-user-bubble: var(--bubble);--learn-card: var(--color-surface);--learn-complete: #e8f5f0;--learn-complete-border: #a8bbb5;--learn-complete-title: #3f6e62;--learn-complete-text: #57534e;--learn-message-text: var(--prose-ink);--learn-message-meta: var(--ink-3);--learn-scrollbar-thumb: #d6d3d1;--learn-concept-mastered: #4a7c6f;--learn-concept-current: #d4a574;--learn-concept-current-ink: #856747;--learn-concept-current-ring: #fdf6ee;--learn-message-size: 15px;--learn-message-leading: 1.65;--learn-opening-leading: 25.5px;--learn-message-tracking: .02px;--learn-user-leading: 23.5px;--learn-user-padding-top: 13px;--learn-user-padding-bottom: 5.5px;--learn-user-turn-tail: 3.75px;--learn-chat-width: 703px;--learn-composer-width: 751px;--learn-attachment-border: var(--color-hairline);--learn-attachment-text: #78716c;--learn-attachment-radius: 13px;--learn-mastery-border: #fbf1e0;--learn-mastery-chip: #fbf1e0;--learn-mastery-title-size: 14px;--learn-mastery-icon-size: 26px;--learn-mastery-evidence-leading: 19.5px;--learn-mastery-chip-size: 11.5px;--learn-mastery-chip-leading: 24px;--learn-evidence: var(--color-surface);--learn-summary: var(--color-bg);--learn-summary-header: var(--color-paper-deep);--learn-complete-action-height: 31.5px;--learn-command-selected: var(--sel-warm);--learn-command-icon: var(--color-bg);--learn-command-muted: #b7b3af;--learn-diagram-light: #fbf6ed;--learn-diagram-dark: #f5ebde;--learn-diagram-ink: #292724;--journey-bg: var(--color-bg);--journey-ink: var(--ink-2);--journey-muted: var(--ink-3);--journey-line: var(--color-hairline);--journey-scrollbar: #8b8b8b;--reader-border: var(--color-hairline);--reader-secondary: var(--color-ink-soft);--reader-faint: #b7b3af;--reader-active: var(--accent-wash);--reader-quote: var(--callout-note-bg);--reader-quote-border: #d4a574;--reader-success: #10b981;--reader-scrollbar: #a8a29e;--reader-toolbar-bg: var(--color-paper-deep);--import-backdrop: rgb(28 25 23 / 35%);--import-drop-border: #d6d3d1;--import-drop-active: #faf6ef;--page: var(--color-bg);--surface: var(--color-surface);--rail: var(--color-rail);--muted: var(--color-muted);--line: var(--color-border);--tint: var(--color-accent-soft)}:root[data-theme=dark]{--learn-attachment-border: #44403c;--learn-attachment-text: #b3ada4;--learn-scrollbar-thumb: #57534e;--learn-mastery-border: #604833;--learn-mastery-chip: #483c30;--learn-evidence: #2d2b28;--learn-summary: #302d29;--learn-summary-header: #44403c;--learn-diagram-light: #392f27;--learn-diagram-dark: #483c30;--learn-diagram-ink: #f0ede7;--import-drop-border: #78716c;--import-drop-active: #392f27;--reader-faint: #a8a29e;--reader-quote-border: #a5825e;--reader-success: #6ac6a2;--reader-scrollbar: #78716c;--reader-toolbar-bg: #302d29;--fp-peach: #392f27;--fp-learn: #98abbf;--fp-master: #98b391;--fp-review: #c99478;--fp-peach-border: #604833;--fp-day-active: #443a28;--fp-review-badge: #4b322c;--fp-review-border: #6b4034;--fp-review-red: #eb9278;--review-amber: #d9b47e;--review-amber-soft: #443827;--review-critical-soft: #4b322c;--review-solid-soft: #2f3b2c;--me-secondary: #b3ada4;--me-navigation-muted: #b3ada4;--me-danger: #f87171;--me-faint: #a8a29e;--me-placeholder: #9f9a94;--me-switch: #57534e;--shelf-icon-bg: #44403c;--shelf-icon-ink: #b3ada4;--shelf-cover-epub: #3c3b33;--shelf-cover-pdf: #413b50;--course-detail-chip: #44403c;--course-detail-meta: #a8a29e;--course-detail-purchased: #6ac6a2;--library-complete-cover: #413b50;--library-green: #92b8ab;--library-red: #e99b83;--library-olive: #bcb689;--library-blue: #a6b5d1;--library-violet: #b9aed7;--library-amber: #cfac84;--library-due-bg: #543c33;--learn-command-icon: #383530;--learn-command-muted: #b3ada4;--learn-header: #282623;--learn-sidebar: #242320;--learn-notes: #282623;--learn-card: #302d29;--learn-complete: #29453d;--learn-complete-border: #577b6f;--learn-complete-title: #a0c7b9;--learn-complete-text: #c4c9c3;color-scheme:dark;--color-surface: var(--surf-1);--color-surface-raised: var(--surf-2);--color-rail: var(--paper-deep);--color-danger: #e08a7a}:root{--color-secondary: var(--color-ink-soft);--color-faint: var(--ink-3);--color-subtle: var(--ink-3);--color-disabled: var(--hair-strong);--color-tooltip-bg: #1c1917;--color-tooltip-ink: #fff;--color-control-border: var(--color-hairline);--color-focus-border: var(--hair-strong);--color-divider: var(--color-hairline);--color-selection: var(--sel-warm);--color-scrollbar: #8b8b8b;--base-header-border: var(--color-hairline);--base-header-surface: var(--color-bg);--base-brand-border: #516c60;--base-brand-fill: #536c60;--base-brand-meta: #66766d;--base-secondary: var(--color-ink-soft);--base-eyebrow: #536d5f;--base-title: var(--color-text);--base-card-border: var(--color-hairline);--base-card-shadow: #354b3f03;--base-icon-surface: #edf3ee;--base-icon-ink: #557761;--base-link: #476650;--base-status: #587f65;--base-intro-icon: #5c7a66;--base-avatar-fill: #e3ede4;--base-avatar-ink: #4b6e54;--base-author: #546a5c;--base-copy: #3d4e44;--base-user-fill: #e5ede6;--base-cursor: #698970;--base-check-fill: #dcece0;--base-verdict-border: #c8ddcc;--base-verdict-fill: #f9fcf9;--base-evidence: #4d5f52;--base-evidence-border: #bbd0bf;--base-complete-icon: #5f8068;--base-option-fill: #eff5ef;--base-option-border: #829d87;--base-input-fill: #fbfcfb;--base-disabled-fill: #f4f7f4;--base-error-border: #e5cfc8;--base-error-fill: #fdf7f4;--base-error-ink: #854434;--base-error-text: #954335;--base-composer-backdrop: var(--color-bg);--base-composer-border: #cbdacf;--base-composer-shadow: #354b3f05;--base-input-placeholder: #718075;--base-send-disabled: #85978a;--shell-rail-border: var(--color-hairline);--shell-popover-shadow: #29272412;--shell-progress: #96b29e;--shell-monogram-bg: #ebefe6;--shell-monogram-border: #e0e6da;--shell-monogram-ink: #657655;--shell-day-ink: #87938c;--shell-day-fill: #e0eae2;--shell-day-active-ink: #5b7a64;--shell-dot: #84a78e;--shell-mastered: #648c71;--shell-invitation: #8da996;--shell-collection-shadow: #354b3f0a;--shell-cover-bg: #e3ece5;--shell-favorite: #829888;--shell-favorite-hover: #ffffff66;--shell-favorite-selected: #8c7d49;--shell-cover-icon: #7c9c8524;--shell-olive-bg: #edece0;--shell-olive-ink: #655f46;--shell-blue-bg: #e3ebee;--shell-blue-ink: #47626c;--shell-progress-filled: #8fad97;--shell-due: #ad694d;--shell-new-course-border: #cbd8ce;--color-white: #ffffff;--ui-card-shadow: #26231c03;--ui-tab-shadow: #26231c05;--ui-toggle-shadow: #26231c15;--library-menu-shadow: #29272414}:root[data-theme=dark]{--color-tooltip-bg: #e6dfd4;--color-tooltip-ink: #292724;--color-control-border: #57534e;--color-scrollbar: #78716c;--base-header-border: var(--color-border);--base-header-surface: var(--color-rail);--base-brand-border: #8ac2a9;--base-brand-meta: var(--color-muted);--base-secondary: var(--color-muted);--base-eyebrow: #a0c7b9;--base-title: var(--color-text);--base-card-border: var(--color-border);--base-card-shadow: #00000010;--base-icon-surface: #29453d;--base-icon-ink: #8ac2a9;--base-link: #a0c7b9;--base-status: #8ac2a9;--base-intro-icon: #8ac2a9;--base-avatar-fill: #29453d;--base-avatar-ink: #8ac2a9;--base-author: #a0c7b9;--base-copy: var(--color-text);--base-user-fill: #383530;--base-cursor: #8ac2a9;--base-check-fill: #29453d;--base-verdict-border: #577b6f;--base-verdict-fill: #29453d;--base-evidence: var(--color-text);--base-evidence-border: #577b6f;--base-complete-icon: #8ac2a9;--base-option-fill: #29453d;--base-option-border: #8ac2a9;--base-input-fill: var(--color-surface);--base-disabled-fill: var(--color-bg);--base-error-border: #6b4034;--base-error-fill: #4b322c;--base-error-ink: #ec957a;--base-error-text: #ec957a;--base-composer-backdrop: var(--color-bg);--base-composer-border: var(--color-border);--base-composer-shadow: #00000020;--base-input-placeholder: var(--color-muted);--base-send-disabled: var(--color-muted);--shell-rail-border: var(--color-border);--shell-popover-shadow: #00000030;--shell-monogram-bg: var(--color-accent-soft);--shell-monogram-border: var(--color-border);--shell-monogram-ink: var(--color-text);--shell-day-ink: var(--color-muted);--shell-day-fill: #29453d;--shell-day-active-ink: #8ac2a9;--shell-mastered: #8ac2a9;--shell-collection-shadow: #00000025;--shell-cover-bg: var(--color-accent-soft);--shell-favorite: var(--color-muted);--shell-favorite-hover: #ffffff14;--shell-favorite-selected: #cfac84;--shell-cover-icon: #8ac2a924;--shell-olive-bg: #443a28;--shell-olive-ink: #bcb689;--shell-blue-bg: #303b48;--shell-blue-ink: #a6b5d1;--shell-due: #ec957a;--shell-new-course-border: var(--color-border);--ui-card-shadow: #00000014;--ui-tab-shadow: #00000020;--ui-toggle-shadow: #00000030;--library-menu-shadow: #00000040}:root{--reader-assistant-bg: #f7f6f2;--reader-assistant-border: #e8e6e0;--reader-assistant-ink: #373732;--reader-assistant-header-border: #eae8e3;--reader-assistant-meta: #a09e96;--reader-assistant-control: #8b8880;--reader-assistant-scrollbar: #c6c3bc;--reader-assistant-bubble: #6b625b;--reader-assistant-on-bubble: #ffffff;--reader-assistant-copy: #45413c;--reader-assistant-cursor: #9a7754;--reader-assistant-empty: #a39f96;--reader-assistant-status: #969087;--reader-assistant-error-border: #e8d8c7;--reader-assistant-error-bg: #fcf5ed;--reader-assistant-link: #936b46;--reader-assistant-composer-border: #e2dfd7;--reader-assistant-input: #393732;--reader-assistant-placeholder: #aaa69e;--reader-assistant-send: #3a3732;--reader-assistant-disabled: #e8e5de;--reader-assistant-quote-bg: #f6f3ed;--reader-assistant-quote-text: #8e8578;--reader-popup-hover: #ffffff20;--reader-popup-shadow: #27221c21;--reader-assistant-shadow: #29231c09;--reader-assistant-composer-shadow: #2c271b04;--reader-toggle-shadow: #00000005;--reader-sidebar-shadow: #29272412;--reader-drawer-shadow: #29272409;--reader-segment-shadow: #0000000d;--reader-popover-shadow: #00000014;--reader-modal-shadow: #0003;--reader-modal-backdrop: rgb(0 0 0 / 40%);--reader-code-bg: #f6f5f3;--reader-inline-code-bg: #f3f2ef;--reader-code-border: #eeecea;--reader-code-comment: #a8a29e;--reader-code-string: #2f7d5b;--reader-code-number: #b45309;--reader-code-keyword: #7c3aed;--reader-code-function: #1d4ed8;--reader-search-match: #f1e6ca;--reader-highlight-fill: rgba(255, 230, 0, .4);--reader-highlight-line: #bd9a5d;--reader-compact-ink: #1b1917;--reader-chapter-heading: #aaa6a1;--reader-book-scrollbar: #aaa6a1}:root[data-theme=dark]{--reader-assistant-bg: var(--color-bg);--reader-assistant-border: var(--reader-border);--reader-assistant-ink: var(--color-text);--reader-assistant-header-border: var(--reader-border);--reader-assistant-meta: var(--reader-faint);--reader-assistant-control: var(--reader-secondary);--reader-assistant-scrollbar: var(--reader-scrollbar);--reader-assistant-copy: var(--color-text);--reader-assistant-cursor: var(--color-accent);--reader-assistant-empty: var(--reader-faint);--reader-assistant-status: var(--reader-secondary);--reader-assistant-error-border: var(--color-border);--reader-assistant-error-bg: var(--reader-quote);--reader-assistant-link: var(--color-accent);--reader-assistant-composer-border: var(--color-border);--reader-assistant-input: var(--color-text);--reader-assistant-placeholder: var(--reader-faint);--reader-assistant-send: var(--color-primary);--reader-assistant-disabled: var(--color-border);--reader-assistant-quote-bg: var(--reader-quote);--reader-assistant-quote-text: var(--reader-secondary);--reader-popup-hover: #00000014;--reader-popup-shadow: #00000040;--reader-assistant-shadow: #00000030;--reader-assistant-composer-shadow: #00000014;--reader-toggle-shadow: #00000020;--reader-sidebar-shadow: #00000030;--reader-drawer-shadow: #00000030;--reader-segment-shadow: #00000020;--reader-popover-shadow: #00000040;--reader-modal-shadow: #0006;--reader-code-bg: #1f1e1c;--reader-inline-code-bg: #1f1e1c;--reader-code-border: #44403c;--reader-code-string: #86c9a7;--reader-code-number: #f0b47a;--reader-code-keyword: #c4a5ff;--reader-code-function: #93b4ff;--reader-search-match: var(--color-accent-soft);--reader-highlight-fill: rgba(255, 225, 0, .32);--reader-highlight-line: #d5b47a;--reader-compact-ink: var(--color-text);--reader-chapter-heading: var(--reader-faint);--reader-book-scrollbar: var(--reader-scrollbar);--explore-promo-bg: #2c3029;--explore-green: #83c6aa;--explore-purchased-bg: #244c3c;--explore-bundle-bg: #392f27;--explore-gift-bg: #3b3426;--explore-gold-border: #6a523b;--explore-mini-bg: #302d29;--explore-envelope-paper: #4b4236;--explore-envelope-fold: #3d352b;--explore-envelope-shadow: #241e19;--learn-concept-current-ring: #392f27;--learn-concept-current-ink: #49321d}:root{--me-switch-shadow: #00000010;--me-card-shadow: #00000008;--me-dialog-backdrop: rgb(28 25 23 / 35%);--me-dialog-shadow: #00000018}:root[data-theme=dark]{--me-switch-shadow: #00000030;--me-card-shadow: #00000020;--me-dialog-shadow: #00000040}:root{--color-editorial-meta: var(--label-ink);--color-card-surface: transparent;--color-ink-wash: var(--hover-warm);--shadow-popover: var(--x-shadow)}:root{--radius-lg: var(--r-md);--radius-xl: var(--r-md);--radius-card: var(--r-md);--radius-control: var(--r-sm)}:root[data-theme=dark]{--color-card-surface: var(--surf-1)}:root{--chat-user-bubble: #6b625a;--chat-user-ink: #ffffff;--chat-success-ink: #356653;--chat-success-bg: #e8f3ed;--chat-success-badge-bg: #d9efe3;--chat-stage-ink: #925016;--chat-stage-bg: #fbefdf}:root[data-theme=dark]{--chat-user-bubble: #625950;--chat-success-ink: #a0c7b9;--chat-success-bg: #293b32;--chat-success-badge-bg: #344d3d;--chat-stage-ink: #e5b47e;--chat-stage-bg: #3d3025}:root{--ease-panel: cubic-bezier(.16, 1, .3, 1);--dur-panel: .3s;--ease-standard: cubic-bezier(.4, 0, .2, 1);--dur-fast: .15s;--dur-exit: .1s;--dur-modal: .2s;--dur-menu: .1s;--dur-credit-enter: .12s;--dur-credit-exit: 67ms;--dur-mode-exit: 67ms;--dur-quick-ask-enter: .3s;--dur-quick-ask-exit: .1s;--dur-map: .45s;--dur-map-draw: .5s;--ease-map: cubic-bezier(.42, 0, .58, 1);--dur-journey-enter: .27s;--dur-journey-exit: .33s;--delay-journey-line: .3s;--dur-slide-exit: 50ms;--dur-slide-enter: .25s;--delay-slide-line: 80ms;--dur-presentation-enter: 67ms;--dur-presentation-content: .3s;--dur-presentation-exit: .2s;--dur-handnote-enter: .22s}html[data-theme-changing],html[data-theme-changing] *,html[data-theme-changing] *:before,html[data-theme-changing] *:after{transition:none!important}.fx-drawer{transition:transform var(--dur-2) var(--ease),opacity var(--dur-2) var(--ease)}.fx-drawer.is-closed{transform:translate(16px);opacity:0;pointer-events:none}.fx-pop{transform-origin:var(--origin, top left);transition:transform var(--dur-2) var(--ease),opacity var(--dur-1) var(--ease)}.fx-pop.is-closed{transform:translateY(4px) scale(.98);opacity:0;pointer-events:none}.fx-fade{animation:fx-fade var(--dur-2) var(--ease) both}@keyframes fx-fade{0%{opacity:0;transform:translateY(2px)}}@media(prefers-reduced-motion:reduce){.fx-drawer,.fx-pop,.fx-fade{transition:none;animation:none}:root{--dur-panel: 0ms;--dur-fast: 0ms;--dur-exit: 0ms;--dur-modal: 0ms;--dur-menu: 0ms;--dur-credit-enter: 0ms;--dur-credit-exit: 0ms;--dur-mode-exit: 0ms;--dur-quick-ask-enter: 0ms;--dur-quick-ask-exit: 0ms;--dur-map: 0ms;--dur-map-draw: 0ms;--dur-journey-enter: 0ms;--dur-journey-exit: 0ms;--delay-journey-line: 0ms;--dur-slide-exit: 0ms;--dur-slide-enter: 0ms;--delay-slide-line: 0ms;--dur-presentation-enter: 0ms;--dur-presentation-content: 0ms;--dur-presentation-exit: 0ms;--dur-handnote-enter: 0ms}}.btn,.btn-primary{display:inline-flex;align-items:center;justify-content:center;gap:8px;height:36px;padding:0 16px;border:1px solid var(--hair-strong);border-radius:var(--r-sm);background:transparent;color:var(--ink);font-size:14px;font-weight:500;white-space:nowrap}.btn:hover:not(:disabled){background:var(--hover-warm)}:where(:root[data-theme=dark]) .btn{background:var(--surf-1)}:where(:root[data-theme=dark]) .btn:hover:not(:disabled){background:var(--surf-2)}.btn-primary{border-color:var(--ink);background:var(--ink);color:var(--paper)}.btn-primary:hover:not(:disabled){background:color-mix(in srgb,var(--ink) 88%,var(--paper))}.btn-ghost,:where(:root[data-theme=dark]) .btn-ghost{border-color:transparent;background:transparent;color:var(--ink-2)}.btn-ghost:hover:not(:disabled){background:var(--hover-warm);color:var(--ink)}.btn-sm{height:28px;padding:0 10px;gap:6px;border-radius:var(--r-sm);font-size:13px}.btn>svg,.btn-primary>svg{width:16px;height:16px;flex:none}.btn:disabled,.btn-primary:disabled{opacity:.38;cursor:not-allowed}.icon-btn{width:36px;height:36px;display:inline-grid;place-items:center;flex:none;border:0;border-radius:var(--r-sm);background:transparent;color:var(--ink-2)}.icon-btn.sm{width:28px;height:28px;border-radius:var(--r-sm)}.icon-btn:hover:not(:disabled){background:var(--hover-warm);color:var(--ink)}.icon-btn[aria-pressed=true]{background:var(--sel-warm);box-shadow:inset 0 0 0 1px var(--sel-line);color:var(--ink)}.icon-btn:disabled{color:var(--ink-3);opacity:.5;cursor:default}.item{display:flex;align-items:center;gap:10px;min-height:36px;padding:8px 12px;border-radius:var(--r-sm);color:var(--ink-2);font-size:14px;line-height:1.5}.item:hover{background:var(--hover-warm);color:var(--ink)}.item.on,.item[aria-current=page],.item[aria-selected=true]{background:var(--sel-warm);box-shadow:inset 0 0 0 1px var(--sel-line);color:var(--ink);font-weight:600}.item[aria-disabled=true]{color:var(--ink-3);pointer-events:none}.tabs{display:flex;gap:24px;border-bottom:1px solid var(--hair)}.tabs>a,.tabs>button{padding:10px 0;margin-bottom:-1px;border:0;border-bottom:1px solid transparent;background:transparent;color:var(--ink-3);font-size:14px}.tabs>:is(a,button):hover{color:var(--ink)}.tabs>:is(a,button):is(.on,[aria-selected=true],[aria-current=page]){border-bottom-color:var(--ink);color:var(--ink);font-weight:600}.seg{display:inline-flex;gap:2px;padding:3px;border-radius:10px;background:var(--paper-deep);box-shadow:inset 0 0 0 1px var(--hair)}.seg>a,.seg>button{height:30px;padding:0 14px;display:inline-flex;align-items:center;gap:6px;border:0;border-radius:7px;background:transparent;color:var(--ink-3);font-size:14px}.seg>:is(a,button):hover{color:var(--ink)}.seg>:is(.on,[aria-pressed=true],[aria-selected=true]){background:var(--paper);box-shadow:0 0 0 1px var(--hair);color:var(--ink);font-weight:600}:where(:root[data-theme=dark]) .seg>:is(.on,[aria-pressed=true],[aria-selected=true]){background:var(--surf-3)}.card{padding:24px;border:1px solid var(--hair);border-radius:var(--r-md);background:transparent}.card.raised{background:var(--raise)}:where(:root[data-theme=dark]) .card.raised{background:var(--surf-1)}.field{width:100%;height:36px;padding:0 12px;border:1px solid var(--hair-strong);border-radius:var(--r-sm);background:transparent;color:var(--ink);font-size:14px}textarea.field{height:auto;min-height:72px;padding:8px 12px;line-height:1.6}:where(:root[data-theme=dark]) .field{background:var(--surf-1)}.field::-moz-placeholder{color:var(--ink-3)}.field::placeholder{color:var(--ink-3)}.field:hover:not(:disabled){border-color:var(--ink-3)}.field:disabled{background:var(--paper-deep);color:var(--ink-3)}.btn,.btn-primary,.icon-btn,.item,.tabs>a,.tabs>button,.seg>a,.seg>button,.field{transition:background-color var(--dur-1) var(--ease),color var(--dur-1) var(--ease),box-shadow var(--dur-1) var(--ease),border-color var(--dur-1) var(--ease)}:is(.btn,.btn-primary,.icon-btn,.item):focus-visible{outline:2px solid var(--focus-ring-soft);outline-offset:2px}:root textarea{resize:none}:where(button,a:is(.btn,.btn-primary,.primary-button,.secondary-button,.subtle-button,.ui-pill,.ui-icon-button,.ui-filter-chip,.icon-btn,.learn-back-courses,.reader-back,.book-reader-back,.course-preparation-back,.public-back,.public-content-button,.public-post-read,.rv-button,.fp-continue,.fp-empty-action,.fp-review-button,.fp-graph-explanation,.library-continue-cta,.reader-pager-link,.reader-tutor-entry__button,.reader-tutor-entry__relearn,.wrap-up-primary,.import-complete-link,.mindmap-return,.rail-link,.rail-action,.app-pro,.bk-actions .go,.mindmap-outline-foot>a,.generated-image-actions>a,.state-actions>a,.mastered-actions>a,.review-round-complete-actions>a,.learning-notebook-actions>a)):not(:where(svg *,.user-message-editable,.user-bubble,.chat-message,.user-message,.tutor-message,[class^=message-],[class*=" message-"])){border-radius:var(--r-sm)}:where(.send-button,.user-edit-send,.explanation-attachment,.btn-primary,.primary-button,.rv-button-primary,.me-primary-button,.wrap-up-primary,.library-continue-cta,.fp-continue,.question-submit,.reader-ask-primary,.reader-highlights-primary,.plan-cta):where(button,a[href]):not(:where(svg *,.user-message-editable,.user-bubble,.chat-message,.user-message,.tutor-message,[class^=message-],[class*=" message-"],:disabled,[aria-disabled=true],[disabled],.stop-button,.library-delete-confirm,.bk-delete-confirm)){position:relative}@media(prefers-reduced-motion:no-preference){:where(.send-button,.user-edit-send,.explanation-attachment,.btn-primary,.primary-button,.rv-button-primary,.me-primary-button,.wrap-up-primary,.library-continue-cta,.fp-continue,.question-submit,.reader-ask-primary,.reader-highlights-primary,.plan-cta):where(button,a[href]):not(:where(svg *,.user-message-editable,.user-bubble,.chat-message,.user-message,.tutor-message,[class^=message-],[class*=" message-"],:disabled,[aria-disabled=true],[disabled],.stop-button,.library-delete-confirm,.bk-delete-confirm)):after{content:"";position:absolute;z-index:1;top:0;right:0;bottom:0;left:0;pointer-events:none;border-radius:inherit;corner-shape:inherit;background:linear-gradient(115deg,transparent 35%,var(--button-shimmer-light) 50%,transparent 65%);background-size:300% 100%;background-repeat:no-repeat;background-position:100% 0;opacity:0}:where(.send-button,.user-edit-send,.explanation-attachment,.btn-primary,.primary-button,.rv-button-primary,.me-primary-button,.wrap-up-primary,.library-continue-cta,.fp-continue,.question-submit,.reader-ask-primary,.reader-highlights-primary,.plan-cta):where(button,a[href]):not(:where(svg *,.user-message-editable,.user-bubble,.chat-message,.user-message,.tutor-message,[class^=message-],[class*=" message-"],:disabled,[aria-disabled=true],[disabled],.stop-button,.library-delete-confirm,.bk-delete-confirm)):is(:hover,:focus-visible):after{animation:button-shimmer-sweep .64s ease-in-out 1}}:root{--button-shimmer-light: rgb(255 255 255 / .18)}:root[data-theme=dark]{--button-shimmer-light: rgb(255 255 255 / .09)}@keyframes button-shimmer-sweep{0%{opacity:0;background-position:100% 0}20%,80%{opacity:1}to{opacity:0;background-position:0% 0}}@supports (corner-shape: squircle){:where(.btn,.btn-primary,.ui-icon-button,.ui-filter-chip,.learn-back-courses,.reader-back,.course-preparation-back,.public-back,.composer-tool,.composer-style,.composer-research,.quick-command-trigger,.question-submit,.question-hint-button,.choice-question-actions>button):where(button,a[href]):not(:where(svg *,.user-message-editable,.user-bubble,.chat-message,.user-message,.tutor-message,[class^=message-],[class*=" message-"])){corner-shape:squircle}}:root{--pr-paper: var(--paper, var(--color-bg, #f4f3f0));--pr-paper-img: var(--paper-img, none);--pr-ink: var(--ink, #2b2926);--pr-ink-2: var(--ink-2, #55514b);--pr-ink-3: var(--ink-3, #6a655d);--pr-label: var(--label, #8593a3);--pr-label-ink: var(--label-ink, #52606f);--pr-hair: var(--hair, rgba(43, 41, 38, .1));--pr-hair-strong: var(--hair-strong, rgba(43, 41, 38, .18));--pr-raise: var(--raise, rgba(255, 255, 255, .62));--pr-hover: var(--hover, rgba(43, 41, 38, .04));--pr-hover-warm: var(--hover-warm, rgba(158, 110, 60, .055));--pr-sel-warm: var(--sel-warm, rgba(158, 110, 60, .085));--pr-sel-line: var(--sel-line, rgba(43, 41, 38, .22));--pr-mark: var(--mark);--pr-strong-band: var(--strong-band, var(--mark));--pr-hl-bg: var(--hl-bg);--pr-ok: var(--ok, #4a6646);--pr-accent: var(--accent, #9e4528);--pr-bubble: var(--bubble, #3a3733);--pr-bubble-ink: var(--bubble-ink, #f4f1ea);--pr-code-bg: var(--code-bg, #f4f0e8);--pr-code-ink: var(--code-ink, #2b2926);--pr-code-kw: var(--code-kw, #7a4a2a);--pr-code-str: var(--code-str, #4e5f72);--pr-code-cm: var(--code-cm, #6a655d);--pr-fig-bg: var(--fig-bg, rgba(255, 255, 255, .5));--pr-focus-ring: var(--focus-ring, #52606f);--pr-serif: var(--serif, var(--font-serif, "Noto Serif CJK SC", serif));--pr-sans: var(--sans, var(--font-sans, -apple-system, sans-serif));--pr-mono: "SF Mono", ui-monospace, Menlo, Consolas, monospace;--pr-dur-1: var(--dur-1, .12s);--pr-dur-2: var(--dur-2, .2s);--pr-ease: var(--ease, cubic-bezier(.2, .7, .2, 1));--prose-ink: #34312d;--prose-selection: rgba(255, 230, 0, .4);--pr-callout-note-bg: var(--callout-note-bg, #fbf1e6);--pr-callout-note-ink: var(--callout-note-ink, #7a4a2a);--pr-callout-tip-bg: var(--callout-tip-bg, #eef1ea);--pr-callout-warn-bg: var(--callout-warn-bg, #f7eae5);--pr-callout-warn-ink: var(--callout-warn-ink, #8a3b22);--callout-note-line: #b9835a;--callout-tip-line: #7e9a78;--callout-tip-ink: #3f5a3b;--callout-warn-line: #b9735c;--pr-ask-bg: var(--ask-bg, #22201d);--ask-ink: #f1ece3;--ask-tag: #d9b47e;--ask-line: transparent}:root[data-theme=dark]{--pr-paper: var(--paper, var(--color-bg, #21201e));--pr-ink: var(--ink, #ece8e1);--pr-ink-2: var(--ink-2, #bdb7ad);--pr-ink-3: var(--ink-3, #a39d93);--pr-label: var(--label, #8796a8);--pr-label-ink: var(--label-ink, #9aa8b8);--pr-hair: var(--hair, rgba(236, 232, 225, .16));--pr-hair-strong: var(--hair-strong, rgba(236, 232, 225, .26));--pr-raise: var(--raise, rgba(255, 248, 236, .06));--pr-hover: var(--hover, rgba(255, 250, 240, .035));--pr-hover-warm: var(--hover-warm, rgba(255, 236, 210, .045));--pr-sel-warm: var(--sel-warm, rgba(255, 236, 210, .075));--pr-sel-line: var(--sel-line, rgba(236, 232, 225, .3));--pr-mark: var(--mark);--pr-strong-band: var(--strong-band, var(--mark));--pr-hl-bg: var(--hl-bg);--pr-ok: var(--ok, #93ac8c);--pr-accent: var(--accent, #c4917a);--pr-bubble: var(--bubble, #3b3935);--pr-bubble-ink: var(--bubble-ink, #f1ede6);--pr-code-bg: var(--code-bg, #2a2826);--pr-code-ink: var(--code-ink, #e6e1d9);--pr-code-kw: var(--code-kw, #d9a57e);--pr-code-str: var(--code-str, #a6b6c8);--pr-code-cm: var(--code-cm, #a39d93);--pr-fig-bg: var(--fig-bg, rgba(255, 250, 240, .035));--pr-focus-ring: var(--focus-ring, #9aa8b8);--prose-ink: #e2ddd5;--prose-selection: rgba(255, 225, 0, .32);--pr-callout-note-bg: var(--callout-note-bg, rgba(200, 150, 100, .09));--pr-callout-note-ink: var(--callout-note-ink, #d8b08e);--pr-callout-tip-bg: var(--callout-tip-bg, rgba(143, 175, 136, .1));--pr-callout-warn-bg: var(--callout-warn-bg, rgba(196, 145, 122, .1));--pr-callout-warn-ink: var(--callout-warn-ink, #dda48e);--callout-note-line: #b98b66;--callout-tip-line: #7e9a78;--callout-tip-ink: #a9c4a2;--callout-warn-line: #b9735c;--pr-ask-bg: var(--ask-bg, #322f2b);--ask-ink: #f1ece3;--ask-tag: #d9b47e;--ask-line: rgba(236, 232, 225, .16)}:root{--cb-bg: #ffffff;--cb-fg: #393a34;--cb-head: #f7f7f7;--cb-border: #f0f0f0;--cb-head-divider: #f0f0f0;--cb-label: #6a737d;--cb-copy: #393a34;--cb-copy-hover-bg: #22222218;--cb-copy-hover: #393a34;--cb-copy-done: #1c6b48;--cb-focus: #1c6b48;--cb-selection: #22222218;--cb-comment: #a0ada0;--cb-keyword: #1e754f;--cb-string: #b56959;--cb-number: #2f798a;--cb-function: #59873a;--cb-type: #2e8f82;--cb-property: #998418;--cb-operator: #ab5959;--cb-tag: #1e754f;--cb-attr: #b07d48}:root[data-theme=dark]{--cb-bg: #121212;--cb-fg: #dbd7caee;--cb-head: #181818;--cb-border: #191919;--cb-head-divider: #191919;--cb-label: #959da5;--cb-copy: #dbd7caee;--cb-copy-hover-bg: #eeeeee18;--cb-copy-hover: #dbd7caee;--cb-copy-done: #4d9375;--cb-focus: #4d9375;--cb-selection: #eeeeee18;--cb-comment: #758575dd;--cb-keyword: #4d9375;--cb-string: #c98a7d;--cb-number: #4c9a91;--cb-function: #80a665;--cb-type: #5da994;--cb-property: #b8a965;--cb-operator: #cb7676;--cb-tag: #4d9375;--cb-attr: #bd976a}:is(.reader-code,.message-text pre) .tok-comment{color:var(--cb-comment);font-style:italic}:is(.reader-code,.message-text pre) .tok-keyword{color:var(--cb-keyword)}:is(.reader-code,.message-text pre) .tok-string{color:var(--cb-string)}:is(.reader-code,.message-text pre) .tok-number{color:var(--cb-number)}:is(.reader-code,.message-text pre) .tok-function{color:var(--cb-function)}:is(.reader-code,.message-text pre) .tok-type{color:var(--cb-type)}:is(.reader-code,.message-text pre) .tok-property{color:var(--cb-property)}:is(.reader-code,.message-text pre) .tok-operator{color:var(--cb-operator)}:is(.reader-code,.message-text pre) .tok-tag{color:var(--cb-tag)}:is(.reader-code,.message-text pre) .tok-attr{color:var(--cb-attr)}:is(.reader-code,.message-text pre) ::-moz-selection{background:var(--cb-selection);color:inherit}:is(.reader-code,.message-text pre) ::selection{background:var(--cb-selection);color:inherit}.prose ::-moz-selection,.prose::-moz-selection,.reader-prose ::-moz-selection,.book-prose ::-moz-selection{background:var(--prose-selection, rgba(255, 230, 0, .4));color:inherit}.prose ::selection,.prose::selection,.reader-prose ::selection,.book-prose ::selection{background:var(--prose-selection, rgba(255, 230, 0, .4));color:inherit}:root[data-theme=dark] :is(.prose,.reader-prose,.book-prose) ::-moz-selection,:root[data-theme=dark] :is(.prose,.reader-prose,.book-prose)::-moz-selection{background:#ffe10052;color:#f5f1ea}:root[data-theme=dark] :is(.prose,.reader-prose,.book-prose) ::selection,:root[data-theme=dark] :is(.prose,.reader-prose,.book-prose)::selection{background:#ffe10052;color:#f5f1ea}:root .message-text.prose{font-family:var(--pr-sans);white-space:normal;text-spacing-trim:normal;text-autospace:normal;hanging-punctuation:allow-end;line-break:strict;counter-reset:prose-eq}:root .message-text.prose:not(:is(.user-bubble,.demo-user-bubble) *){font-size:16px;line-height:1.85;letter-spacing:normal;color:var(--prose-ink)}:root .message-text.prose.prose--reply:not(:is(.user-bubble,.demo-user-bubble) *){font-size:15px;line-height:1.8}:root .message-text.prose :is(p,li,h1,h2,h3,h4,h5,h6,blockquote,ol,ul){margin:0}:root .message-text.prose p{white-space:pre-wrap;overflow-wrap:anywhere}:root .message-text.prose>*+*,:root .message-text.prose :is(li,blockquote,.callout-body)>*+*{margin-top:1em}:root .message-text.prose :is(li,.callout-body)>*+*{margin-top:.5em}:root .message-text.prose :is(h1,h2,h3,h4,h5,h6){color:var(--pr-ink);font-weight:600;text-spacing-trim:trim-start;font-feature-settings:"halt"}:root .message-text.prose h1{font:600 31px/1.3 var(--pr-serif);letter-spacing:.04em}:root .message-text.prose h2{font:600 22px/1.4 var(--pr-serif);letter-spacing:.03em}:root .message-text.prose *+h2{margin-top:48px;padding-top:40px;border-top:1px solid var(--pr-hair)}:root .message-text.prose h3{font:600 18px/1.5 var(--pr-serif)}:root .message-text.prose *+h3{margin-top:32px}:root .message-text.prose :is(h4,h5,h6){font:600 16px/1.6 var(--pr-sans)}:root .message-text.prose *+:is(h4,h5,h6){margin-top:24px}:root .message-text.prose h2+*{margin-top:16px}:root .message-text.prose :is(h3,h4,h5,h6)+*{margin-top:10px}:root .message-text.prose--reply h2{font-size:19px}:root .message-text.prose--reply *+h2{margin-top:28px;padding-top:24px}:root .message-text.prose--reply h3{font-size:16px}:root .message-text.prose--reply *+h3{margin-top:20px}:root :is(.message-text.prose,.book-reader-prose) :is(b,strong){font-weight:600;color:var(--pr-ink)}:root .message-text.prose :is(b,strong):not(:is(h1,h2,h3,h4,h5,h6,th) *){padding:0 2px;background:linear-gradient(transparent 55%,var(--pr-strong-band, var(--pr-mark)) 55%);-webkit-box-decoration-break:clone;box-decoration-break:clone}:root :is(.user-bubble,.demo-user-bubble) .message-text.prose :is(b,strong){padding:0;background:none}:root[data-theme=dark] :is(.message-text.prose,.book-reader-prose) :is(b,strong):not(:is(h1,h2,h3,h4,h5,h6,th) *){color:#f5f1ea}:root[data-theme=dark] .message-text.prose :is(b,strong):not(:is(h1,h2,h3,h4,h5,h6,th) *){background:linear-gradient(transparent 55%,var(--pr-strong-band) 55%)}:root[data-theme=dark] :is(.user-bubble,.demo-user-bubble) .message-text.prose :is(b,strong){background:none}:root .message-text.prose mark{font-weight:600;color:var(--pr-ink);background:linear-gradient(transparent 58%,var(--pr-mark) 58%);-webkit-box-decoration-break:clone;box-decoration-break:clone;padding:0 1px}:root :is(.message-text.prose,.book-reader-prose) mark.reader-highlight{padding:0;margin:0;border:0;border-radius:0;box-shadow:none;outline:0;display:inline;vertical-align:baseline;font:inherit;line-height:inherit;background-image:none;background-size:auto;background-position:0 0;-webkit-box-decoration-break:clone;box-decoration-break:clone;color:inherit;background-color:var(--reader-mark-fill);text-decoration-line:underline;text-decoration-color:var(--reader-mark-line);text-decoration-thickness:1.5px;text-underline-offset:.24em;-webkit-text-decoration-skip-ink:none;text-decoration-skip-ink:none}:root[data-theme=dark] .message-text.prose mark{color:#f5f1ea;background:linear-gradient(transparent 52%,#e8825f61 52%)}:root[data-theme=dark] :is(.message-text.prose,.book-reader-prose) mark.reader-highlight{color:#f5f1ea;background-image:none;background-color:var(--reader-mark-fill)}:root .message-text.prose :is(b,strong):not(:is(h1,h2,h3,h4,h5,h6,th) *) :is(mark.reader-highlight,.book-reader-underline){box-shadow:none;background-color:transparent;background-image:linear-gradient(transparent 55%,var(--pr-strong-band, var(--pr-mark)) 55%),linear-gradient(var(--reader-mark-fill),var(--reader-mark-fill));background-clip:content-box,padding-box;background-origin:content-box,padding-box;background-repeat:no-repeat;background-size:100% 100%}:root[data-theme=dark] .message-text.prose :is(b,strong):not(:is(h1,h2,h3,h4,h5,h6,th) *) :is(mark.reader-highlight,.book-reader-underline){box-shadow:none;background-color:transparent;background-image:linear-gradient(transparent 55%,var(--pr-strong-band) 55%),linear-gradient(var(--reader-mark-fill),var(--reader-mark-fill))}:root .message-text.prose .hl{background:var(--pr-hl-bg);border-radius:2px;padding:1px 2px}:root .message-text.prose u{-webkit-text-decoration:underline 1px var(--pr-ink-3);text-decoration:underline 1px var(--pr-ink-3);text-underline-offset:3px}:root .message-text.prose a{color:var(--pr-accent, var(--accent));text-decoration:none;transition:color var(--dur-2, .2s) var(--ease, ease)}:root .message-text.prose a .link-label{background-image:linear-gradient(currentColor,currentColor);background-position:0 100%;background-repeat:no-repeat;background-size:0% 1.5px;transition:background-size var(--dur-2, .2s) var(--ease, ease)}:root .message-text.prose a:hover{color:color-mix(in srgb,var(--pr-accent, var(--accent)) 72%,var(--pr-ink))}:root .message-text.prose a:hover .link-label{background-size:100% 1.5px}:root .message-text.prose a:focus-visible .link-label{background-size:100% 1.5px}:root .message-text.prose a .ext-icon{content:none!important;display:none!important}:root :is(.message-text.prose,.reader-prose) a:is([href^="http://" i],[href^="https://" i]):after{content:"";display:inline-block;width:.7em;height:.7em;margin-inline-start:.16em;vertical-align:.02em;pointer-events:none;background-color:currentColor;-webkit-mask:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='currentColor' stroke-width='1.6' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M7 7h10v10M7 17 17 7'/%3E%3C/svg%3E") center / contain no-repeat;mask:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='currentColor' stroke-width='1.6' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M7 7h10v10M7 17 17 7'/%3E%3C/svg%3E") center / contain no-repeat;opacity:1;transform:translate(0);transition:transform var(--dur-1, .12s) var(--ease, ease);transition-delay:0ms}:root :is(.message-text.prose,.reader-prose) a:is([href^="http://" i],[href^="https://" i]):where(:hover,:focus-visible):after{transform:translate(.08em,-.08em);transition-delay:var(--dur-2, .2s)}@media(prefers-reduced-motion:reduce){:root :is(.message-text.prose,.reader-prose) a:is([href^="http://" i],[href^="https://" i]):after{transition:none;transition-delay:0ms;transform:none}}:root .message-text.prose :not(pre)>code{font-family:var(--pr-mono);font-size:.88em;padding:1px 5px;border:0;border-radius:4px;background:var(--pr-raise);box-shadow:inset 0 0 0 1px var(--pr-hair);color:var(--pr-ink);overflow-wrap:anywhere}:root .message-text.prose .code-head{display:flex;align-items:center;height:34px;padding:0 8px 0 14px;border:1px solid var(--cb-border);border-bottom-color:var(--cb-head-divider);border-radius:10px 10px 0 0;background:var(--cb-head);box-shadow:none;font:12px/1 var(--pr-sans);letter-spacing:.04em;color:var(--cb-label);-webkit-user-select:none;-moz-user-select:none;user-select:none}:root .message-text.prose .code-copy{margin-left:auto;display:inline-flex;align-items:center;gap:4px;height:24px;padding:0 8px;border:0;border-radius:6px;background:transparent;color:var(--cb-copy);font:inherit;letter-spacing:0;cursor:pointer;transition:background-color var(--pr-dur-1) var(--pr-ease),color var(--pr-dur-1) var(--pr-ease)}:root .message-text.prose .code-copy:hover{background:var(--cb-copy-hover-bg);color:var(--cb-copy-hover)}:root .message-text.prose .code-copy[data-state=copied]{color:var(--cb-copy-done)}:root .message-text.prose .code-copy:focus-visible{outline:2px solid var(--cb-focus);outline-offset:1px}:root .message-text.prose .code-copy svg{width:13px;height:13px;stroke-width:1.6}:root .message-text.prose pre,:root .learning-workspace .message-text.prose pre.code-block{margin:0;padding:12px 16px 14px;border:1px solid var(--cb-border);border-radius:10px;background:var(--cb-bg);box-shadow:none;font:13.5px/1.7 var(--pr-mono);color:var(--cb-fg);-moz-tab-size:4;-o-tab-size:4;tab-size:4}:root .message-text.prose *+.code-head{margin-top:1em}:root .message-text.prose .code-head+pre,:root .learning-workspace .message-text.prose .code-head+pre.code-block{margin-top:0;border-top:0;border-radius:0 0 10px 10px}:root .message-text.prose pre code{padding:0;border:0;background:none;box-shadow:none;font:inherit;color:inherit}:root .message-text.prose .math-inline .katex{font-size:1.06em}:root .message-text.prose .math-display{display:grid;grid-template-columns:minmax(20px,1fr) minmax(0,auto) minmax(20px,1fr);align-items:center;-moz-column-gap:20px;column-gap:20px;margin:1.4em 0 .4em;padding:0;font-family:var(--pr-serif);overflow-x:auto}:root .message-text.prose .math-display:before{content:"";height:1px;background:var(--pr-hair)}:root .message-text.prose .math-display:after{counter-increment:prose-eq;content:"(" counter(prose-eq) ")";justify-self:stretch;text-align:right;background:linear-gradient(var(--pr-hair),var(--pr-hair)) left center / calc(100% - 3em) 1px no-repeat;font:13px/1 var(--pr-serif);color:var(--pr-label-ink)}:root .message-text.prose .math-display:has(.tag):after{counter-increment:none;content:"";background-size:100% 1px}:root .message-text.prose .math-display>.katex-display{margin:0;padding:4px 0;min-width:0}:root .message-text.prose .math-display .katex{font-size:20px;color:var(--pr-ink)}:root .message-text.prose .katex .frac-line{border-bottom-width:1px!important}:root .message-text.prose div.math-fallback{margin-top:1.4em;text-align:center;font:italic 18px/1.6 var(--pr-serif);color:var(--pr-ink)}:root .message-text.prose blockquote:not(.callout,.ask-block){padding:2px 0 2px 18px;border-left:2px solid var(--pr-hair-strong);color:var(--pr-ink-2);text-spacing-trim:trim-start}:root .message-text.prose blockquote cite{display:block;margin-top:6px;font:normal 12px/1.6 var(--pr-sans);letter-spacing:.04em;color:var(--pr-label-ink)}:root .message-text.prose .ask-block{position:relative;padding:14px 18px 14px 52px;border:0;border-radius:6px;background:var(--pr-ask-bg);box-shadow:inset 0 0 0 1px var(--ask-line);font-size:15.5px;line-height:1.7;font-weight:500;color:var(--ask-ink)}:root .message-text.prose .ask-block :is(p,li,strong,b,a,mark){color:inherit}:root .message-text.prose .ask-block mark{background:linear-gradient(transparent 58%,var(--pr-strong-band, var(--pr-mark)) 58%)}:root .message-text.prose .ask-tag{position:absolute;top:16px;left:18px;display:grid;place-items:center;width:22px;height:22px;border:1px solid var(--ask-tag);border-radius:50%;font:600 12px/1 var(--pr-serif);color:var(--ask-tag)}:root .message-text.prose .ask-tag+*{margin-top:0}:root .message-text.prose :is(ol,ul){padding-left:1.6em}:root .message-text.prose ol{list-style:decimal}:root .message-text.prose ol>li::marker{font-family:var(--pr-serif);font-size:.92em;color:var(--pr-ink)}:root .message-text.prose ul{list-style:none}:root .message-text.prose ul>li{position:relative}:root .message-text.prose ul>li:not(.task-list-item):before{content:"";position:absolute;top:.92em;left:-1.05em;width:4px;height:1px;background:var(--pr-ink-3)}:root .message-text.prose li+li{margin-top:.35em}:root .message-text.prose li>:is(ol,ul){margin-top:.35em;padding-left:1.4em}:root .message-text.prose .task-list-item>input[type=checkbox]{accent-color:var(--pr-ok)}:root .message-text.prose hr{height:1px;margin:40px 0;border:0;background:var(--pr-hair)}:root .message-text.prose .dinkus{margin:40px 0;text-align:center;font:16px/1 var(--pr-serif);letter-spacing:.9em;color:var(--pr-ink-3)}:root .message-text.prose :is(hr,.dinkus)+*{margin-top:0}:root .message-text.prose figure:not([class]){margin:1.6em 0;padding:24px;border:1px solid var(--pr-hair);border-radius:12px;background:var(--pr-fig-bg)}:root .message-text.prose figcaption{margin-top:14px;text-align:center;font-size:12px;letter-spacing:.04em;color:var(--pr-label-ink)}:root :is(.user-bubble,.demo-user-bubble) .message-text.prose{--prose-ink: currentColor;--pr-ink: currentColor;--pr-ink-2: color-mix(in srgb, currentColor 84%, transparent);--pr-ink-3: color-mix(in srgb, currentColor 60%, transparent);--pr-label-ink: color-mix(in srgb, currentColor 66%, transparent);--pr-hair: color-mix(in srgb, currentColor 16%, transparent);--pr-hair-strong: color-mix(in srgb, currentColor 28%, transparent);--pr-raise: color-mix(in srgb, currentColor 9%, transparent);--pr-hover: color-mix(in srgb, currentColor 12%, transparent);--pr-code-bg: rgba(0, 0, 0, .18);--pr-code-ink: currentColor}:root .message-text.prose>:is(.summary-table-card,.quote-card)+*,:root .message-text.prose>*+:is(.summary-table-card,.quote-card){margin-top:1.2em}:root{--scrollbar-thumb: rgb(43 41 38 / 24%);--scrollbar-thumb-hover: rgb(43 41 38 / 44%);--scrollbar-size: 14px;--scrollbar-gap: 3px}:root[data-theme=dark]{--scrollbar-thumb: rgb(236 232 225 / 22%);--scrollbar-thumb-hover: rgb(236 232 225 / 40%)}@supports not selector(::-webkit-scrollbar){*{scrollbar-width:thin;scrollbar-color:var(--scrollbar-thumb) transparent}*:hover{scrollbar-color:var(--scrollbar-thumb-hover) transparent}}::-webkit-scrollbar{width:var(--scrollbar-size);height:var(--scrollbar-size)}::-webkit-scrollbar-track,::-webkit-scrollbar-corner{background:transparent}::-webkit-scrollbar-thumb{min-height:32px;border:var(--scrollbar-gap) solid transparent;border-radius:999px;background:var(--scrollbar-thumb);background-clip:padding-box}::-webkit-scrollbar-thumb:hover,::-webkit-scrollbar-thumb:active{background:var(--scrollbar-thumb-hover);background-clip:padding-box}::-webkit-scrollbar-button{display:none}.ui-control{position:relative;display:inline-flex;flex:none;width:16px;height:16px;vertical-align:middle}.ui-control-hidden,.ui-control>.ui-control-input{-webkit-appearance:none;-moz-appearance:none;appearance:none;position:absolute;width:1px;height:1px;margin:0;padding:0;border:0;opacity:0;clip-path:inset(50%)}.ui-control>.ui-control-input{top:0;right:0;bottom:0;left:0;z-index:1;width:100%;height:100%;clip-path:none;cursor:pointer}.ui-control-mark{display:block;width:100%;height:100%;border:1px solid var(--hair-strong);border-radius:4px;background:var(--surf-1);pointer-events:none}.ui-control-input:checked+.ui-control-mark{border-color:var(--ink);background:var(--ink)}.ui-control-checkbox .ui-control-input:checked+.ui-control-mark:after{content:"";position:absolute;left:5px;top:2px;width:5px;height:9px;border:solid var(--paper);border-width:0 1.5px 1.5px 0;transform:rotate(45deg)}.ui-control-radio .ui-control-mark{border-radius:50%}.ui-control-radio .ui-control-input:checked+.ui-control-mark{box-shadow:inset 0 0 0 3px var(--surf-1)}.ui-control-switch{width:32px;height:20px}.ui-control-switch .ui-control-mark{border-radius:999px;background:var(--paper-deep)}.ui-control-switch .ui-control-mark:after{content:"";position:absolute;left:3px;top:3px;width:14px;height:14px;border-radius:50%;background:var(--ink-3);transition:transform var(--dur-1) var(--ease)}.ui-control-switch .ui-control-input:checked+.ui-control-mark:after{background:var(--paper);transform:translate(12px)}.ui-control-input:focus-visible+.ui-control-mark{outline:none;border-color:var(--ink-3)}.ui-control:has(input:disabled){opacity:.38}.ui-control input:disabled{cursor:not-allowed}.ui-control:has(input:enabled):hover .ui-control-mark{border-color:var(--ink-3)}.ui-slider{position:relative;display:block;width:100%;height:24px}.ui-slider>.ui-slider-input{position:absolute;top:0;right:0;bottom:0;left:0;z-index:1;width:100%;height:100%;margin:0;opacity:0;cursor:pointer}.ui-slider-track{position:absolute;top:10px;left:0;right:0;height:4px;overflow:hidden;border-radius:999px;background:var(--hair-strong);pointer-events:none}.ui-slider-track>span{display:block;width:var(--slider-position);height:100%;background:var(--ink)}.ui-slider-thumb{position:absolute;left:calc(7px + (100% - 14px) * var(--slider-progress));top:5px;width:14px;height:14px;border:1px solid var(--ink);border-radius:50%;background:var(--paper);transform:translate(-50%);pointer-events:none}.ui-slider-input:focus-visible~.ui-slider-thumb{outline:none;border-color:var(--ink-3)}.ui-slider:focus-within .ui-slider-track{background:var(--ink-3)}.ui-slider:has(input:disabled){opacity:.38}.ui-slider-input:disabled{cursor:not-allowed}:root .message-text .task-list-item>input[type=checkbox]{-webkit-appearance:none;-moz-appearance:none;appearance:none;width:14px;height:14px;border:1px solid var(--hair-strong);border-radius:3px;background:var(--surf-1)}:root .message-text .task-list-item>input[type=checkbox]:checked{border-color:var(--ink);background:var(--ink);background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 14 14'%3E%3Cpath d='m3 7 2.5 2.5L11 4' fill='none' stroke='%23f4f3f0' stroke-width='1.4'/%3E%3C/svg%3E")}:root[data-theme=dark] .message-text .task-list-item>input[type=checkbox]:checked{background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 14 14'%3E%3Cpath d='m3 7 2.5 2.5L11 4' fill='none' stroke='%23211f1c' stroke-width='1.4'/%3E%3C/svg%3E")}:root summary{list-style:none}:root summary::-webkit-details-marker{display:none}:root summary::marker{content:""}:root summary:focus-visible{outline:2px solid var(--focus-ring-soft);outline-offset:2px;border-radius:var(--r-sm)}:root summary:not(:has(svg)):before{content:"";display:inline-block;width:6px;height:6px;margin-right:9px;border-right:1px solid currentColor;border-bottom:1px solid currentColor;transform:rotate(-45deg);vertical-align:2px}:root details[open]>summary:not(:has(svg)):before{transform:rotate(45deg);vertical-align:3px}:root[data-theme=dark] .ui-control-mark{background:var(--surf-2)}:root[data-theme=dark] .ui-control-input:checked+.ui-control-mark{background:var(--ink)}:root[data-theme=dark] .ui-control-radio .ui-control-input:checked+.ui-control-mark{box-shadow:inset 0 0 0 3px var(--surf-2)}@media(prefers-reduced-motion:reduce){.ui-control-mark:after{transition:none}}:root{--focus-ring-soft: color-mix(in srgb, var(--focus-ring) 55%, transparent);--field-focus-edge: rgba(43, 41, 38, .34);--composer-focus-border: var(--field-focus-edge);--composer-focus-glow: none}:root[data-theme=dark]{--field-focus-edge: rgba(236, 232, 225, .42)}:focus:not(:focus-visible){outline:none}:root :is(input,textarea,select,[contenteditable]):not(:where(.learn-conversation textarea,.session-quick-ask input,.learning-workspace .question-option input,.learning-workspace .question-input-control textarea,.learning-workspace .choice-question-card textarea)),:root :is(input,textarea,select,[contenteditable]):not(:where(.learn-conversation textarea,.session-quick-ask input,.learning-workspace .question-option input,.learning-workspace .question-input-control textarea,.learning-workspace .choice-question-card textarea)):is(:focus,:focus-visible){outline:none!important;box-shadow:none!important}:root :is(.ui-search,.course-search,.new-topic form,.reader-search,.reader-search-input-row,.reader-highlights-search,.composer:not(.learn-conversation .composer),.reader-assistant-box,.quick-ask-input-wrap:not(.session-quick-ask .quick-ask-input-wrap),.knowledge-personal-note-field,.question-option:not(.learning-workspace .question-option),.question-input-control:not(.learning-workspace .question-input-control),.import-link-form,.library-dialog-field):focus-within{border-color:var(--field-focus-edge)!important;outline:none!important;box-shadow:none!important}:root :is(.me-editor-field,.me-free-text,.account-settings-name-editor):has(:is(input,textarea,select):focus-visible){background-color:var(--hover);border-radius:var(--r-sm)}:root .field:focus{border-color:var(--hair-strong);background-color:var(--hover)}:root :is([role=dialog],[role=alertdialog],dialog){background-color:var(--overlay-surface)}:root :is([role=menu],[popover],.ui-select-list,.quick-command-menu,.rail-menu-feedback,.reader-selection-notice,.mindmap-error){background-color:var(--popover-surface)}:root :is(body,body *){font-variant-numeric:lining-nums tabular-nums}:root :is(.num,time,output,.ui-tab-count,.ui-filter-count,.count-badge,.cs-count,.book-reader-tool-count,.mindmap-fold-count,.co-stats b,.fp-figs b,.week-totals strong,.subscription-monthly>strong,.subscription-monthly b,.subscription-price,.subscription-price small,.plan-price strong,.plan-credit-amount h3,.account-settings-key-value strong,.learn-usage>span:last-child,.lesson-progress-big b,.lesson-progress-kv dd,.rv-percent,.learn-page[data-learning-mode=review] .review-v1-accuracy-big>b,.review-v1-rating-counts dd,.wrap-up-stats strong,.journey-concept-stats dd,.journey-summary dd,.lecture-card-counter,.lecture-nav-counter,.structured-lecture-card-counter,.async-lecture-navigation output,.question-review-index){font-family:var(--font-num);font-variant-numeric:lining-nums tabular-nums;vertical-align:baseline}:root :is(.ui-tabs .ui-tab,.learn-page.learning-workspace .learn-modes .ui-tab,.ui-filter-chip):has(:is(.ui-tab-count,.ui-filter-count)){align-items:baseline}:root :is(.num,.ui-tab-count,.ui-filter-count){align-items:baseline;line-height:inherit;vertical-align:baseline}:root .ui-tab:has(.ui-tab-count)>.ui-tab-icon,:root .ui-filter-chip:has(.ui-filter-count)>svg{align-self:center}:root :is(.cs-num,.co-num,.library-chapters em,.reader-section-number,.lecture-slide-list button span,.async-lecture-directory button>span,.concept-opening h3>span,.journey-concept-number,.mindmap-outline-number,.new-course-step-number,.lecture-point-number){font-family:var(--font-num);font-variant-numeric:lining-nums tabular-nums;font-size-adjust:cap-height .72}:root .course-reader-v1 .reader-prose h2:before{font-family:var(--font-num);font-size:14px;font-variant-numeric:lining-nums tabular-nums;font-size-adjust:cap-height .72}:root :is(.lecture-slide-list button,.async-lecture-directory button){align-items:baseline}:root{--chat-mastered-bg: #e6f2ed;--chat-mastered-border: #9cc5b3;--chat-mastered-ink: #2f6b52;--chat-mastered-text: #3d4a44;--chat-mastered-btn-bg: #ffffff;--chat-mastered-btn-border: #c9d9d1;--chat-mastered-btn-ink: #2b2926;--chat-mastered-glow: rgb(76 175 132 / .28);--chat-warn-bg: #fbe9e5;--chat-warn-bar: #b5402a;--chat-warn-icon: #c0503a;--chat-warn-title: #2a1f1c;--chat-tip-bg: #fdf3ea;--chat-tip-bar: #d9a066;--chat-tip-icon: #d08a3c;--chat-tip-title: #2a2219;--chat-key-bg: #f6f0e1;--chat-key-bar: #b08a3e;--chat-key-icon: #9a7426;--chat-key-title: #2a2316;--chat-callout-text: #3b3833;--chat-strong-ink: #1d1b18;--chat-think-bg: transparent;--chat-think-ink: #8b8781;--chat-think-border: rgb(115 109 100 / .16);--chat-jump-bg: #fffdf9;--chat-jump-hover: #eee8df;--chat-jump-border: #e6e4de;--chat-jump-ink: #2b2926;--chat-jump-shadow: 0 2px 4px rgb(43 36 28 / .08), 0 5px 14px rgb(43 36 28 / .08);--chat-confetti-1: #d6a85a;--chat-confetti-2: #4caf84;--chat-confetti-3: #e57a5f;--chat-confetti-4: #6aa8e8;--chat-confetti-5: #a58be0}:root[data-theme=dark]{--chat-mastered-bg: #1f2b26;--chat-mastered-border: #3c6b55;--chat-mastered-ink: #7fcfa4;--chat-mastered-text: #b9c6bf;--chat-mastered-btn-bg: #232a27;--chat-mastered-btn-border: #3a4a42;--chat-mastered-btn-ink: #e6ece8;--chat-mastered-glow: rgb(127 207 164 / .22);--chat-warn-bg: #2b1c19;--chat-warn-bar: #d0603f;--chat-warn-icon: #e07a5f;--chat-warn-title: #f0e6e2;--chat-tip-bg: #2a2117;--chat-tip-bar: #c99a5b;--chat-tip-icon: #e0b070;--chat-tip-title: #f1e8dc;--chat-key-bg: #26221a;--chat-key-bar: #c8a55a;--chat-key-icon: #d9b46a;--chat-key-title: #f1ead8;--chat-callout-text: #cfcac2;--chat-strong-ink: #f5f2ec;--chat-think-bg: transparent;--chat-think-ink: #a09a92;--chat-think-border: rgb(189 183 173 / .16);--chat-jump-bg: #141210;--chat-jump-hover: #393128;--chat-jump-border: #3a3a3a;--chat-jump-ink: #e6e3dd;--chat-jump-shadow: 0 2px 4px rgb(0 0 0 / .2), 0 5px 14px rgb(0 0 0 / .18);--chat-confetti-1: #e6b96a;--chat-confetti-2: #5fc396;--chat-confetti-3: #ef8c72;--chat-confetti-4: #7db6f0;--chat-confetti-5: #b49cec}:root:root :is(.learn-page.learning-workspace[data-learning-mode] .tutor-message,body) .message-text.prose :is(b,strong){color:var(--chat-strong-ink)}:root:root .mastery-card.mastered-card{margin:18px 0 8px;padding:20px 24px 18px;border:0;border-radius:14px;background:var(--chat-mastered-bg);color:var(--chat-mastered-text);overflow:hidden;animation:chat-mastered-enter .36s cubic-bezier(.2,.7,.2,1) both,chat-mastered-glow .9s ease-out .24s both}.mastered-card .mastered-heading{display:flex;align-items:center;gap:10px;margin:0 0 10px;font:600 20px/1.4 var(--pr-serif);color:var(--chat-mastered-ink);text-wrap:balance;overflow-wrap:anywhere}.mastered-card .mastered-sep{margin:0 4px}.mastered-card .mastered-check{width:20px;height:20px;margin-top:0;flex:none;fill:none;stroke:currentColor;stroke-width:2.4;stroke-linecap:round;stroke-linejoin:round;stroke-dasharray:24;stroke-dashoffset:0;animation:chat-mastered-check .32s ease-out .18s both}.mastered-card .mastered-lines{margin:0 0 0 30px;padding:0;list-style:none}.mastered-card .mastered-lines li{margin:0;padding:0;font-size:14px;line-height:2;color:var(--chat-mastered-text);text-wrap:pretty;overflow-wrap:anywhere}.mastered-card .mastered-lines li:before{content:none}.mastered-card .mastered-evidence{margin:8px 0 0 30px;font-size:13px;color:var(--chat-mastered-text)}.mastered-card .mastered-evidence summary{width:-moz-fit-content;width:fit-content;cursor:pointer;color:var(--chat-mastered-ink);opacity:.85}.mastered-card .mastered-evidence p{margin:4px 0 0;line-height:1.7;overflow-wrap:anywhere}.mastered-card .mastered-actions{display:flex;flex-wrap:wrap;gap:10px;margin:16px 0 0}:root:root .mastered-card .mastered-actions :is(button,a){display:inline-flex;align-items:center;gap:6px;min-height:36px;padding:6px 14px;border:0;border-radius:10px;background:var(--chat-mastered-btn-bg);font:14px/1.5 var(--pr-sans);color:var(--chat-mastered-btn-ink);text-decoration:none;cursor:pointer;transition:transform .16s ease-out,box-shadow .16s ease-out,background-color .16s ease-out}.mastered-card .mastered-actions svg{width:15px;height:15px}@media(hover:hover)and (pointer:fine){:root:root .mastered-card .mastered-actions :is(button,a):hover:not(:disabled){box-shadow:0 1px 4px #00000014;transform:translateY(-1px)}}:root:root .mastered-card .mastered-actions :is(button,a):active:not(:disabled){transform:translateY(1px);background:color-mix(in srgb,var(--chat-mastered-btn-bg) 88%,var(--chat-mastered-ink))}:root:root .mastered-card .mastered-actions button:disabled{cursor:wait;opacity:.65}@media(max-width:600px){:root:root .mastery-card.mastered-card{padding:16px}.mastered-card .mastered-heading{align-items:flex-start;font-size:18px}.mastered-card .mastered-check{margin-top:3px}:root:root .mastered-card .mastered-actions :is(button,a){min-height:40px}}.mastered-card .mastered-actions :is(button,a):focus-visible,.mastered-card .mastered-evidence summary:focus-visible{outline:2px solid var(--pr-focus-ring);outline-offset:3px}@keyframes chat-mastered-enter{0%{opacity:0;transform:translateY(6px) scale(.985)}to{opacity:1;transform:none}}@keyframes chat-mastered-glow{0%{box-shadow:0 0 0 0 var(--chat-mastered-glow)}45%{box-shadow:0 0 0 10px var(--chat-mastered-glow)}to{box-shadow:0 0 0 0 transparent}}@keyframes chat-mastered-check{0%{stroke-dashoffset:24}to{stroke-dashoffset:0}}@media(prefers-reduced-motion:reduce){:root:root .mastered-card .mastered-actions :is(button,a),:root:root .mastered-card .mastered-actions :is(button,a):hover:not(:disabled),:root:root .mastered-card .mastered-actions :is(button,a):active:not(:disabled){transition:none;transform:none}:root:root .mastery-card.mastered-card,.mastered-card .mastered-check{animation:none}}*,:before,:after{--tw-border-spacing-x: 0;--tw-border-spacing-y: 0;--tw-translate-x: 0;--tw-translate-y: 0;--tw-rotate: 0;--tw-skew-x: 0;--tw-skew-y: 0;--tw-scale-x: 1;--tw-scale-y: 1;--tw-pan-x: ;--tw-pan-y: ;--tw-pinch-zoom: ;--tw-scroll-snap-strictness: proximity;--tw-gradient-from-position: ;--tw-gradient-via-position: ;--tw-gradient-to-position: ;--tw-ordinal: ;--tw-slashed-zero: ;--tw-numeric-figure: ;--tw-numeric-spacing: ;--tw-numeric-fraction: ;--tw-ring-inset: ;--tw-ring-offset-width: 0px;--tw-ring-offset-color: #fff;--tw-ring-color: rgb(59 130 246 / .5);--tw-ring-offset-shadow: 0 0 #0000;--tw-ring-shadow: 0 0 #0000;--tw-shadow: 0 0 #0000;--tw-shadow-colored: 0 0 #0000;--tw-blur: ;--tw-brightness: ;--tw-contrast: ;--tw-grayscale: ;--tw-hue-rotate: ;--tw-invert: ;--tw-saturate: ;--tw-sepia: ;--tw-drop-shadow: ;--tw-backdrop-blur: ;--tw-backdrop-brightness: ;--tw-backdrop-contrast: ;--tw-backdrop-grayscale: ;--tw-backdrop-hue-rotate: ;--tw-backdrop-invert: ;--tw-backdrop-opacity: ;--tw-backdrop-saturate: ;--tw-backdrop-sepia: ;--tw-contain-size: ;--tw-contain-layout: ;--tw-contain-paint: ;--tw-contain-style: }::backdrop{--tw-border-spacing-x: 0;--tw-border-spacing-y: 0;--tw-translate-x: 0;--tw-translate-y: 0;--tw-rotate: 0;--tw-skew-x: 0;--tw-skew-y: 0;--tw-scale-x: 1;--tw-scale-y: 1;--tw-pan-x: ;--tw-pan-y: ;--tw-pinch-zoom: ;--tw-scroll-snap-strictness: proximity;--tw-gradient-from-position: ;--tw-gradient-via-position: ;--tw-gradient-to-position: ;--tw-ordinal: ;--tw-slashed-zero: ;--tw-numeric-figure: ;--tw-numeric-spacing: ;--tw-numeric-fraction: ;--tw-ring-inset: ;--tw-ring-offset-width: 0px;--tw-ring-offset-color: #fff;--tw-ring-color: rgb(59 130 246 / .5);--tw-ring-offset-shadow: 0 0 #0000;--tw-ring-shadow: 0 0 #0000;--tw-shadow: 0 0 #0000;--tw-shadow-colored: 0 0 #0000;--tw-blur: ;--tw-brightness: ;--tw-contrast: ;--tw-grayscale: ;--tw-hue-rotate: ;--tw-invert: ;--tw-saturate: ;--tw-sepia: ;--tw-drop-shadow: ;--tw-backdrop-blur: ;--tw-backdrop-brightness: ;--tw-backdrop-contrast: ;--tw-backdrop-grayscale: ;--tw-backdrop-hue-rotate: ;--tw-backdrop-invert: ;--tw-backdrop-opacity: ;--tw-backdrop-saturate: ;--tw-backdrop-sepia: ;--tw-contain-size: ;--tw-contain-layout: ;--tw-contain-paint: ;--tw-contain-style: }*,:before,:after{box-sizing:border-box;border-width:0;border-style:solid;border-color:#e5e7eb}:before,:after{--tw-content: ""}html,:host{line-height:1.5;-webkit-text-size-adjust:100%;-moz-tab-size:4;-o-tab-size:4;tab-size:4;font-family:var(--font-sans);font-feature-settings:normal;font-variation-settings:normal;-webkit-tap-highlight-color:transparent}body{margin:0;line-height:inherit}hr{height:0;color:inherit;border-top-width:1px}abbr:where([title]){-webkit-text-decoration:underline dotted;text-decoration:underline dotted}h1,h2,h3,h4,h5,h6{font-size:inherit;font-weight:inherit}a{color:inherit;text-decoration:inherit}b,strong{font-weight:bolder}code,kbd,samp,pre{font-family:ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,Liberation Mono,Courier New,monospace;font-feature-settings:normal;font-variation-settings:normal;font-size:1em}small{font-size:80%}sub,sup{font-size:75%;line-height:0;position:relative;vertical-align:baseline}sub{bottom:-.25em}sup{top:-.5em}table{text-indent:0;border-color:inherit;border-collapse:collapse}button,input,optgroup,select,textarea{font-family:inherit;font-feature-settings:inherit;font-variation-settings:inherit;font-size:100%;font-weight:inherit;line-height:inherit;letter-spacing:inherit;color:inherit;margin:0;padding:0}button,select{text-transform:none}button,input:where([type=button]),input:where([type=reset]),input:where([type=submit]){-webkit-appearance:button;background-color:transparent;background-image:none}:-moz-focusring{outline:auto}:-moz-ui-invalid{box-shadow:none}progress{vertical-align:baseline}::-webkit-inner-spin-button,::-webkit-outer-spin-button{height:auto}[type=search]{-webkit-appearance:textfield;outline-offset:-2px}::-webkit-search-decoration{-webkit-appearance:none}::-webkit-file-upload-button{-webkit-appearance:button;font:inherit}summary{display:list-item}blockquote,dl,dd,h1,h2,h3,h4,h5,h6,hr,figure,p,pre{margin:0}fieldset{margin:0;padding:0}legend{padding:0}ol,ul,menu{list-style:none;margin:0;padding:0}dialog{padding:0}textarea{resize:vertical}input::-moz-placeholder,textarea::-moz-placeholder{opacity:1;color:#9ca3af}input::placeholder,textarea::placeholder{opacity:1;color:#9ca3af}button,[role=button]{cursor:pointer}:disabled{cursor:default}img,svg,video,canvas,audio,iframe,embed,object{display:block;vertical-align:middle}img,video{max-width:100%;height:auto}[hidden]:where(:not([hidden=until-found])){display:none}html,.paper-sheet{background-color:var(--paper);background-image:var(--paper-glow),var(--paper-img);background-repeat:no-repeat,repeat,repeat;background-attachment:fixed,fixed,fixed;background-size:100% 100%,var(--paper-size),var(--paper-size)}body{margin:0;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;min-height:100vh;background:transparent;color:var(--ink);font-family:var(--sans);font-size:16px;line-height:1.75;text-rendering:optimizeLegibility}h1,h2,h3{font-family:var(--serif)}::-moz-selection{background:var(--sel-bg);color:inherit}::selection{background:var(--sel-bg);color:inherit}.\!container{width:100%!important}.container{width:100%}@media(min-width:640px){.\!container{max-width:640px!important}.container{max-width:640px}}@media(min-width:768px){.\!container{max-width:768px!important}.container{max-width:768px}}@media(min-width:1024px){.\!container{max-width:1024px!important}.container{max-width:1024px}}@media(min-width:1280px){.\!container{max-width:1280px!important}.container{max-width:1280px}}@media(min-width:1536px){.\!container{max-width:1536px!important}.container{max-width:1536px}}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border-width:0}.\!visible{visibility:visible!important}.visible{visibility:visible}.invisible{visibility:hidden}.collapse{visibility:collapse}.static{position:static}.fixed{position:fixed}.absolute{position:absolute}.relative{position:relative}.sticky{position:sticky}.isolate{isolation:isolate}.m-7{margin:1.75rem}.\!block{display:block!important}.block{display:block}.inline-block{display:inline-block}.\!inline{display:inline!important}.inline{display:inline}.flex{display:flex}.table{display:table}.grid{display:grid}.contents{display:contents}.hidden{display:none}.h-12{height:3rem}.shrink{flex-shrink:1}.grow{flex-grow:1}.transform{transform:translate(var(--tw-translate-x),var(--tw-translate-y)) rotate(var(--tw-rotate)) skew(var(--tw-skew-x)) skewY(var(--tw-skew-y)) scaleX(var(--tw-scale-x)) scaleY(var(--tw-scale-y))}.resize{resize:both}.truncate{overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.border{border-width:1px}.uppercase{text-transform:uppercase}.lowercase{text-transform:lowercase}.italic{font-style:italic}.ordinal{--tw-ordinal: ordinal;font-variant-numeric:var(--tw-ordinal) var(--tw-slashed-zero) var(--tw-numeric-figure) var(--tw-numeric-spacing) var(--tw-numeric-fraction)}.underline{text-decoration-line:underline}.shadow{--tw-shadow: 0 1px 3px 0 rgb(0 0 0 / .1), 0 1px 2px -1px rgb(0 0 0 / .1);--tw-shadow-colored: 0 1px 3px 0 var(--tw-shadow-color), 0 1px 2px -1px var(--tw-shadow-color);box-shadow:var(--tw-ring-offset-shadow, 0 0 #0000),var(--tw-ring-shadow, 0 0 #0000),var(--tw-shadow)}.\!outline{outline-style:solid!important}.outline{outline-style:solid}.ring{--tw-ring-offset-shadow: var(--tw-ring-inset) 0 0 0 var(--tw-ring-offset-width) var(--tw-ring-offset-color);--tw-ring-shadow: var(--tw-ring-inset) 0 0 0 calc(3px + var(--tw-ring-offset-width)) var(--tw-ring-color);box-shadow:var(--tw-ring-offset-shadow),var(--tw-ring-shadow),var(--tw-shadow, 0 0 #0000)}.blur{--tw-blur: blur(8px);filter:var(--tw-blur) var(--tw-brightness) var(--tw-contrast) var(--tw-grayscale) var(--tw-hue-rotate) var(--tw-invert) var(--tw-saturate) var(--tw-sepia) var(--tw-drop-shadow)}.filter{filter:var(--tw-blur) var(--tw-brightness) var(--tw-contrast) var(--tw-grayscale) var(--tw-hue-rotate) var(--tw-invert) var(--tw-saturate) var(--tw-sepia) var(--tw-drop-shadow)}.transition{transition-property:color,background-color,border-color,text-decoration-color,fill,stroke,opacity,box-shadow,transform,filter,backdrop-filter;transition-timing-function:cubic-bezier(.4,0,.2,1);transition-duration:.15s}.ease-out{transition-timing-function:cubic-bezier(0,0,.2,1)}*{box-sizing:border-box}button,textarea,input{font:inherit}button,a,input,textarea{-webkit-tap-highlight-color:transparent}button,a{touch-action:manipulation}button{cursor:pointer;border-radius:var(--r-sm)}button:disabled{cursor:not-allowed}a{color:inherit;text-decoration:none}button:focus-visible,a:focus-visible,[role=tab]:focus-visible,[role=menuitem]:focus-visible,[tabindex]:not([tabindex="-1"]):focus-visible,input:is([type=checkbox],[type=radio],[type=range]):focus-visible{outline:2px solid var(--focus-ring-soft);outline-offset:2px}input:not([type=checkbox],[type=radio],[type=range]):focus-visible{outline:2px solid var(--focus-ring-soft);outline-offset:2px}textarea:focus-visible{outline:2px solid var(--focus-ring-soft);outline-offset:2px}.site-header{border-bottom:1px solid var(--base-header-border);background:transparent}.header-inner{max-width:2072px;margin:auto;padding:35px 59px;display:flex;align-items:center;justify-content:space-between;gap:37px}.brand{display:inline-flex;align-items:center;gap:20.5px;font-family:"Noto Serif SC",Songti SC,serif;font-size:26px;font-weight:600;white-space:nowrap}.brand-mark{width:66.5px;height:66.5px;display:inline-grid;place-items:center;border:1px solid var(--base-brand-border);border-radius:20.5px 7.5px;background:var(--base-brand-fill);color:var(--color-white);font-size:24px}.brand small{margin-left:1px;font:18.5px Inter,sans-serif;letter-spacing:3.75px;color:var(--base-brand-meta)}.header-note{font-size:14px;color:var(--base-secondary);letter-spacing:.06em}.home-main{max-width:1953.5px;margin:auto;padding:144.5px 59px 59px}.eyebrow{margin:0;display:flex;align-items:center;gap:16.5px;font-size:14px;letter-spacing:.07em;color:var(--base-eyebrow)}.home-main h1{font-family:var(--font-serif);font-size:clamp(81.5px,7vw,126px);font-weight:500;line-height:1.15;letter-spacing:-.02em;margin:40.5px 0 31.5px;color:var(--base-title)}.home-description{font-size:17px;max-width:777px;line-height:1.9;color:var(--base-secondary)}.course-section{margin-top:100px}.section-heading{display:flex;justify-content:space-between;gap:37px;align-items:baseline;margin-bottom:31.5px}.section-heading h2{font:500 37px "Noto Serif SC",Songti SC,serif;margin:0;color:var(--base-title)}.section-heading>span{font-size:14px;color:var(--base-secondary)}.course-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(536.5px,1fr));gap:37px}.course-card{background:var(--color-surface);border:1px solid var(--base-card-border);padding:50px 55.5px 42.5px;border-radius:var(--radius-card);box-shadow:var(--shadow-card);max-width:1184px}.course-card-top,.course-card-bottom{display:flex;align-items:center;justify-content:space-between;gap:22px}.course-icon{width:85px;height:85px;background:var(--base-icon-surface);color:var(--base-icon-ink);display:grid;place-items:center;border-radius:24px}.course-tag{border:1px solid var(--base-header-border);border-radius:37px;padding:7.5px 18.5px;font-size:13px}.course-card h3{font:600 42.5px/1.5 "Noto Serif SC",Songti SC,serif;color:var(--base-title);margin:39px 0 22px}.course-card>p{font-size:15px;line-height:1.9;color:var(--base-secondary);margin:0 0 46px;max-width:851px}.course-card-bottom>span{font-size:13px;color:var(--base-secondary)}.primary-button{display:inline-flex;justify-content:center;align-items:center;gap:6px;min-height:32px;border:0;border-radius:10px;background:var(--color-primary);color:var(--color-on-primary);padding:0 12px;font-size:13px;font-weight:500;line-height:19.5px}.primary-button:hover:not(:disabled){background:var(--color-primary-hover)}.primary-button:disabled{opacity:.45}.text-link{display:inline-flex;align-items:center;gap:11px;border:0;background:none;padding:0;color:var(--base-link);font-size:14px}.text-link:hover{text-decoration:underline}.course-review-link{margin-top:29.5px}.home-footnote{margin:68.5px 0 0;font-size:13px;color:var(--base-secondary)}.back-link{font-size:14px;display:flex;align-items:center;gap:11px;color:var(--base-secondary)}.learn-main{max-width:1583.5px;margin:auto;padding:59px 59px 0}.lesson-heading{display:flex;gap:37px;align-items:center;justify-content:space-between;margin-bottom:35px}.lesson-heading h1{font:500 46px/1.6 var(--font-serif);letter-spacing:-.02em;color:var(--base-title);margin:18.5px 0 0}.lesson-heading .eyebrow{font-size:13px;letter-spacing:.02em}.lesson-heading .eyebrow>span{color:var(--base-secondary)}.lesson-badge{font-size:12px;display:flex;align-items:center;gap:11px;white-space:nowrap;padding:11px 16.5px;border:1px solid var(--base-card-border);border-radius:55.5px}.lesson-badge>span{width:9px;height:9px;background:var(--base-status);border-radius:50%}.lesson-intro{display:flex;gap:16.5px;align-items:center;border-top:1px solid var(--base-card-border);border-bottom:1px solid var(--base-card-border);padding:22px 0;font-size:13px;color:var(--base-secondary)}.lesson-intro>svg{flex-shrink:0;color:var(--base-intro-icon)}.lesson-intro p{margin:0;line-height:1.7}.message-list{display:flex;flex-direction:column;min-height:296px;gap:53.5px;padding:55.5px 0}.chat-message{display:flex;gap:22px;align-items:flex-start}.tutor-avatar{flex-shrink:0;width:55.5px;height:55.5px;display:grid;place-items:center;background:var(--base-avatar-fill);color:var(--base-avatar-ink);border-radius:50%}.message-content{min-width:0;max-width:1221px}.message-author{margin:5.5px 0 16.5px;color:var(--base-author);font-size:13px;font-weight:600}.message-text{margin:0;color:var(--base-copy);font-size:16px;line-height:1.95;white-space:pre-wrap;overflow-wrap:anywhere}.user-message{justify-content:flex-end;padding-left:81.5px}.user-message .message-content{background:var(--base-user-fill);border:1px solid var(--base-card-border);border-radius:26px 5.5px 26px 26px;padding:24px 33.5px}.stream-cursor{display:inline-block;margin-left:5.5px;width:11px;height:28px;background:var(--base-cursor);vertical-align:middle;animation:pulse 1s ease infinite}.card-row{margin-left:77.5px}.learning-card{background:var(--color-surface);border:1px solid var(--base-card-border);border-radius:var(--radius-card);padding:40.5px 46px}.learning-card h3{font-size:17px;line-height:1.8;font-weight:600;margin:18.5px 0 9px;color:var(--base-title)}.card-eyebrow{display:flex;align-items:center;gap:15px;font-size:13px;font-weight:600;color:var(--base-link);margin:0}.card-check{display:grid;place-items:center;background:var(--base-check-fill);border-radius:50%;width:46px;height:46px}.verdict-card{border-color:var(--base-verdict-border);background:var(--base-verdict-fill)}.review-date{color:var(--base-link);font-size:13px;margin:7.5px 0 31.5px}.verdict-concept{color:var(--base-title);font:500 35px/1.6 "Noto Serif SC",Songti SC,serif;margin:28px 0 0}.evidence{color:var(--base-evidence);line-height:1.95;font-size:15px;margin:0;padding:20.5px 0 20.5px 28px;border-left:1px solid var(--color-hairline)}.card-closing{font-size:13px;line-height:1.8;color:var(--base-secondary);margin:28px 0 0}.complete-card{text-align:center;background:var(--base-verdict-fill);padding:53.5px 46px}.complete-card>svg{color:var(--base-complete-icon);display:block;margin:auto}.complete-card h3{font-family:"Noto Serif SC",Songti SC,serif;font-size:24px}.complete-card>p{font-size:14px;line-height:1.9;margin:15px 0 33.5px}.question-card fieldset{margin:29.5px 0 0;border:0;padding:0;min-width:0}.question-options{display:grid;gap:15px}.question-option{display:flex;align-items:flex-start;gap:20.5px;border:1px solid var(--base-header-border);padding:20.5px 24px;border-radius:15px;font-size:15px;line-height:1.7;cursor:pointer}.question-option.selected{background:var(--base-option-fill);border-color:var(--base-option-border)}.question-option input{accent-color:var(--base-link);margin-top:9px;flex-shrink:0}.question-option strong{font-weight:600;margin-right:7.5px}.question-input{display:grid;gap:13px;font-size:14px;color:var(--base-secondary);margin-top:28px}.question-input textarea{width:100%;resize:none;padding:18.5px 22px;border:1px solid var(--base-card-border);border-radius:15px;background:var(--base-input-fill);line-height:1.8;font-size:15px;color:var(--base-copy)}.question-input textarea:disabled{color:var(--base-secondary);background:var(--base-disabled-fill)}.question-submit{margin-top:29.5px}.question-locked{display:flex;align-items:center;gap:9px;font-size:13px;color:var(--base-link);margin:31.5px 0 0}.stream-status{display:flex;align-items:center;gap:15px;font-size:13px;color:var(--base-secondary);min-height:37px;margin:0 0 33.5px 81.5px}.status-dot{width:11px;height:11px;border-radius:50%;background:var(--base-cursor);animation:pulse 1.2s ease infinite}.error-banner{display:flex;align-items:center;justify-content:space-between;gap:29.5px;padding:22px 28px;border:1px solid var(--base-error-border);border-radius:16.5px;background:var(--base-error-fill);margin-bottom:37px;color:var(--base-error-ink);font-size:14px}.error-banner>p{margin:0;line-height:1.8}.error-banner .text-link{flex-shrink:0;color:var(--base-error-ink)}.inline-error{font-size:14px;color:var(--base-error-text);line-height:1.7}.composer-wrap{position:sticky;bottom:0;padding:22px 0 35px;background-color:var(--paper);background-image:var(--paper-glow),var(--paper-img);background-repeat:no-repeat,repeat,repeat;background-attachment:fixed,fixed,fixed;background-size:100% 100%,var(--paper-size),var(--paper-size)}.chat-scroll-anchor{scroll-margin-bottom:296px}.composer{background:var(--color-surface);border:1px solid var(--base-composer-border);border-radius:24px;padding:26px 24px 22px 31.5px;display:flex;align-items:flex-end;gap:22px;box-shadow:var(--shadow-card)}.composer:focus-within{border-color:var(--color-focus-border);box-shadow:none}.composer textarea{flex:1;min-width:0;padding:0;outline:none;border:none;resize:none;background:none;color:var(--base-copy);font-size:15px;line-height:1.8}.composer textarea::-moz-placeholder{color:var(--base-input-placeholder)}.composer textarea::placeholder{color:var(--base-input-placeholder)}.composer textarea:disabled{opacity:.75}.send-button{width:63px;height:63px;flex-shrink:0;border:0;border-radius:16.5px;background:var(--base-link);display:grid;place-items:center;color:var(--color-white)}.send-button:disabled{opacity:.38;cursor:not-allowed}.composer-note{display:flex;justify-content:space-between;gap:22px;margin:16.5px 7.5px 0;font-size:16.5px;color:var(--base-secondary)}@keyframes pulse{50%{opacity:.25}}@media(prefers-reduced-motion:reduce){*,*:before,*:after{animation:none!important;scroll-behavior:auto!important}}@media(max-width:600px){.header-inner{padding:28px 37px}.header-note,.brand small,.section-heading>span,.lesson-heading .eyebrow>span,.lesson-badge{display:none}.home-main{padding:89px 39px 46px}.course-card{padding:42.5px 40.5px 37px}.course-card h3{font-size:24px}.course-grid{grid-template-columns:1fr}.course-card-bottom{align-items:flex-end}.learn-main{padding:46px 33.5px 0}.lesson-heading h1{font-size:24px}.card-row{margin-left:0}.learning-card{padding:37px}.message-list{gap:46px}.message-text{font-size:15px}.tutor-avatar{width:50px;height:50px}.chat-message{gap:16.5px}.composer-note{font-size:15px}}.primary-button{border-radius:var(--r-sm)}:is(.course-card,.learning-card,.composer){background:transparent;box-shadow:none;border-color:var(--hair);border-radius:var(--r-md)}:where(:root[data-theme=dark]) :is(.course-card,.learning-card){background:var(--surf-1)}:is(.home-main h1,.lesson-heading h1,.course-card h3,.learning-card h3){font-family:var(--serif);font-weight:400;letter-spacing:.04em}:is(.eyebrow,.card-eyebrow){color:var(--label-ink);font-size:12px;font-weight:600;letter-spacing:.14em;text-transform:uppercase}.composer:focus-within{border-color:var(--composer-focus-border);box-shadow:var(--composer-focus-glow)}:root{--sitor-sans: Inter, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;--sitor-serif: "Playfair Display", "Instrument Serif", "Songti SC", "STSong", "Noto Serif SC", Georgia, "Times New Roman", serif;--sitor-body: var(--sitor-sans)}.reader-page,.reader-page button,.reader-page input{font-family:var(--sitor-sans)}.reader-page{font-size:16px;line-height:24px}.reader-column{padding-top:40px}.reader-breadcrumb{font-size:13px;line-height:19.5px;color:var(--pr-ink-3)}.reader-article h1{font:400 32px / 41.6px var(--sitor-serif);letter-spacing:-.64px;color:var(--pr-ink);margin:24px 0 12px}.reader-article .reader-article-meta{font-size:13px;line-height:19.5px;color:var(--pr-ink-3);margin:0 0 32px}.reader-article .reader-prose{margin-top:0;font-family:var(--sitor-body, var(--sitor-sans));font-size:16.5px;line-height:29.7px;letter-spacing:.0825px;color:var(--pr-ink)}.reader-prose .message-text{font-size:16.5px;line-height:29.7px}.reader-prose :is(p,.message-text p){margin:0 0 26px}.reader-prose :is(h2,.message-text h2){font:700 23px / 41.4px var(--sitor-sans);letter-spacing:-.23px;margin:56px 0 18px;padding-top:32px;border-top:1px solid var(--reader-border);color:var(--pr-ink)}.reader-prose :is(h3,.message-text h3){font:600 19px / 31px var(--sitor-sans);margin:36px 0 14px;padding:0;border:0}.reader-prose :is(h4,.message-text h4){font:600 16.5px / 29.7px var(--sitor-sans);margin:28px 0 10px}.reader-prose :is(blockquote,.message-text blockquote){font-size:16.5px;line-height:29.7px;margin:24px 0;padding:16px 20px;color:var(--pr-ink-2)}.reader-prose :is(ul,ol){margin:0 0 26px}.reader-prose li{font-size:16.5px;line-height:28.875px;margin:0 0 8px;padding-left:2.97px}.reader-prose a{color:var(--pr-ink)}.reader-prose .reader-code,.reader-prose pre{margin:0 0 26px;font-size:13.5px;line-height:22.5px}.reader-prose :not(pre)>code{font-size:.875em}.reader-prose .reader-figure{margin:0 0 26px}.reader-course-title{font-size:15px;line-height:21px;font-weight:600;color:var(--pr-ink)}.reader-chapters h2{font:600 12px / 18px var(--sitor-sans);letter-spacing:.48px;color:var(--pr-ink-3);margin:0;padding:12px 8px 6px}.reader-chapters a,.reader-chapters .reader-chapter-read{font-size:13px;line-height:18.85px;font-weight:400;padding:9px 10px;color:var(--pr-ink-2)}.reader-chapters a[aria-current]{font-size:13px;font-weight:500;color:var(--pr-ink)}.reader-outline h2{font:600 12px / 18px var(--sitor-sans);letter-spacing:.6px;color:var(--pr-ink-3);padding-left:12px}.reader-outline a{font-size:13px;line-height:29.5px}.reader-prose a{color:var(--accent);text-decoration:none;transition:color var(--dur-2, .2s) var(--ease, ease)}.reader-prose a .link-label{background-image:linear-gradient(currentColor,currentColor);background-position:0 100%;background-repeat:no-repeat;background-size:0% 1.5px;transition:background-size var(--dur-2, .2s) var(--ease, ease)}.reader-prose a:hover{color:color-mix(in srgb,var(--accent) 72%,var(--ink))}.reader-prose a:hover .link-label,.reader-prose a:focus-visible .link-label{background-size:100% 1.5px}.reader-prose a .ext-icon{content:none!important;display:none!important}:is(.reader-modal,.reader-notification-popover,.me-dialog,.explore-unlock-dialog,.explore-small-dialog,.subscription-dialog,.material-import-dialog,.learning-notes-drawer,[role=dialog],[role=menu],[data-radix-popper-content-wrapper]){font-family:var(--sitor-sans);font-size:14px;line-height:1.5}:root :is([role=dialog],[role=alertdialog],dialog):not([data-side],[data-placement]){font-family:var(--font-sans);font-size:var(--dialog-body-size);line-height:var(--dialog-line-height)}:root :is([role=dialog],[role=alertdialog],dialog):not([data-side],[data-placement]):not(:is(.reader-search-dialog,.reader-highlights-dialog,.reader-assistant,.composer-quick-ask,.book-reader-marks-drawer,.learning-settings-dialog,.learning-notes-drawer,.learning-journey-dialog,.reader-image-dialog,.knowledge-handnote-lightbox,.diagram-fullscreen,.lecture-presentation)){padding:var(--dialog-padding)}:root :is([role=dialog],[role=alertdialog],dialog):not([data-side],[data-placement]) :is(.dialog-title,h1[id^=radix-],h2[id^=radix-]),:root :is([role=dialog],[role=alertdialog],dialog):not([data-side],[data-placement])>header h2,:root .book-reader-appearance h2,:root .reader-assistant-header strong,:root .composer-popover-header strong{font-family:var(--font-sans);font-size:var(--dialog-title-size);font-weight:var(--dialog-title-weight);line-height:var(--dialog-line-height);letter-spacing:normal}:root :is(.reader-assistant-header,.learning-notes-drawer .learning-notes-heading,.knowledge-handnote-lightbox header,.diagram-fullscreen>header,.lecture-presentation-header){padding:var(--dialog-gap) var(--dialog-padding)}:root .composer-quick-ask .composer-popover-header{padding:0 var(--dialog-padding) var(--dialog-gap)}:root .composer-quick-ask :is(.quick-ask-tabs,.quick-ask-form,.quick-ask-history){padding-inline:var(--dialog-padding)}:root .composer-quick-ask :is(.quick-ask-form,.quick-ask-history){padding-block:var(--dialog-gap)}:root .learning-notes-drawer .learning-notes-heading h2{color:var(--ink);font:var(--dialog-title-weight) var(--dialog-title-size)/var(--dialog-line-height) var(--font-sans);letter-spacing:normal;text-transform:none}:root :is(.reader-assistant-header span,.composer-popover-header>span,.knowledge-handnote-lightbox header>span,.learning-notes-drawer .learning-notes-heading p){color:var(--dialog-muted);font-size:var(--dialog-meta-size);line-height:var(--dialog-line-height)}:root .learning-settings-dialog .settings-shortcut-row{min-height:var(--dialog-control-height);gap:var(--dialog-gap);padding-block:8px;font-size:var(--dialog-body-size)}:root :is([role=dialog],[role=alertdialog],dialog):not([data-side],[data-placement]) label{font-size:var(--dialog-label-size);font-weight:500;line-height:var(--dialog-line-height)}:root :is([role=dialog],[role=alertdialog],dialog):not([data-side],[data-placement]) :is(input:not([type=checkbox],[type=radio],[type=range]),textarea,select,button,[role=button]){font-size:var(--dialog-control-size);line-height:var(--dialog-line-height)}:root :is([role=dialog],[role=alertdialog],dialog):not([data-side],[data-placement]) :is(select,button:not([aria-label],[role=switch],[role=checkbox],[role=radio],.icon-btn,.reader-modal-close,.import-dropzone)){min-height:var(--dialog-control-height)}:root :is([role=dialog],[role=alertdialog],dialog):not([data-side],[data-placement]) :is(.dialog-meta,.dialog-description,p[id^=radix-],small){font-size:var(--dialog-meta-size);line-height:var(--dialog-line-height);color:var(--dialog-muted)}:root :is([role=dialog],[role=alertdialog],dialog):not([data-side],[data-placement]) input::-moz-placeholder,:root :is([role=dialog],[role=alertdialog],dialog):not([data-side],[data-placement]) textarea::-moz-placeholder{color:var(--dialog-muted)}:root :is([role=dialog],[role=alertdialog],dialog):not([data-side],[data-placement]) input::placeholder,:root :is([role=dialog],[role=alertdialog],dialog):not([data-side],[data-placement]) textarea::placeholder{color:var(--dialog-muted)}:where(:is([role=dialog],[role=alertdialog])[data-state]:not([data-side]):not(:is(.reader-search-dialog,.reader-highlights-dialog,.reader-assistant,.composer-quick-ask,.book-reader-marks-drawer,.learning-settings-dialog,.learning-notes-drawer,.learning-journey-dialog,.reader-image-dialog,.knowledge-handnote-lightbox,.diagram-fullscreen,.lecture-presentation))){transform-origin:center}:where(:is([role=dialog],[role=alertdialog])[data-state=open]:not([data-side]):not(:is(.reader-search-dialog,.reader-highlights-dialog,.reader-assistant,.composer-quick-ask,.book-reader-marks-drawer,.learning-settings-dialog,.learning-notes-drawer,.learning-journey-dialog,.reader-image-dialog,.knowledge-handnote-lightbox,.diagram-fullscreen,.lecture-presentation))){animation:dialog-in .2s var(--ease-out-strong) both}:where(:is([role=dialog],[role=alertdialog])[data-state=closed]:not([data-side]):not(:is(.reader-search-dialog,.reader-highlights-dialog,.reader-assistant,.composer-quick-ask,.book-reader-marks-drawer,.learning-settings-dialog,.learning-notes-drawer,.learning-journey-dialog,.reader-image-dialog,.knowledge-handnote-lightbox,.diagram-fullscreen,.lecture-presentation))){animation:dialog-out .14s var(--ease-out-strong) both}@keyframes dialog-in{0%{opacity:0;scale:.97}}@keyframes dialog-out{to{opacity:0;scale:.98}}@media(prefers-reduced-motion:reduce){@keyframes dialog-in{0%{opacity:0}}@keyframes dialog-out{to{opacity:0}}}
