/* 小模型实验室：白色书页、青绿路径、与教材一致的输入蓝/参数紫。 */
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/* 首页：开放排版，只有实际计算路径使用一个框架。 */
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/* 课程正文：左全局目录，中间书页，右本篇定位。 */
.reader-layout{max-width:1460px;display:grid;grid-template-columns:230px minmax(0,760px) 190px;gap:42px;margin:auto;padding:0 32px}.course-sidebar{position:sticky;top:76px;align-self:start;height:calc(100dvh - 76px);overflow-y:auto;overscroll-behavior:contain;padding:30px 18px 32px 0;border-right:1px solid var(--line);scrollbar-width:thin;scrollbar-color:#dbdfe6 transparent}.sidebar-heading{display:flex;align-items:center;justify-content:space-between;font-size:14px;font-weight:600;margin-bottom:24px}.sidebar-heading>a{color:var(--ink)}.course-progress{font-size:11px;color:var(--muted);margin-bottom:23px}.course-progress strong{float:right;color:var(--accent);font:11px/1.7 var(--mono)}.progress-track{height:3px;border-radius:2px;background:#e4e7ec;margin-top:10px}.progress-track i{display:block;background:var(--accent);height:100%;width:0;transition:width .2s}.sidebar-guides{margin-bottom:20px}.lesson-link{padding:8px 9px 8px 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var(--line);border-radius:5px;overflow:hidden;margin:13px 0 16px}.js .font-controls{display:flex!important}.font-controls button{background:white;width:44px;height:30px;font:13px var(--sans)}.font-controls button:hover{background:var(--soft)}.font-controls span{width:42px;text-align:center;border-inline:1px solid var(--line);font:11px var(--mono);color:#818da2}.reading-settings>span{font-size:11px;color:#818da2}.lesson-goal{font-size:11px;line-height:1.9;color:#7c889e;margin-top:12px}.lesson-finish{display:flex;gap:18px;align-items:center;justify-content:space-between;border-top:1px solid var(--line);padding-top:28px;margin-top:52px}.js .complete-button{display:inline-flex!important;color:var(--accent);font-size:13px;padding:11px 17px;background:var(--accent-wash);border-color:#cdd2da}.complete-button[aria-pressed=true]{background:var(--accent);color:white}.source-link{color:#7b879d;font-size:11px;display:flex;gap:6px;align-items:center}.source-link svg{width:14px}.chapter-nav{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:20px;margin-top:35px}.chapter-nav a{border:1px solid var(--line);border-radius:7px;padding:18px 20px;color:var(--ink);transition:border-color .15s}.chapter-nav a:hover{border-color:#bbc1cc}.chapter-nav a>span{display:flex;justify-content:space-between;font-size:11px;color:#768399;margin-bottom:9px}.chapter-nav svg{width:15px;height:15px}.chapter-nav strong{display:block;font-size:13px;font-weight:500;line-height:1.8}.reader-footer{font-size:11px;color:#818da2;margin-top:42px;padding-top:25px;border-top:1px solid var(--line)}.js .menu-toggle,.js .menu-close{display:none!important}.focus-mode .reader-layout{grid-template-columns:minmax(0,780px);justify-content:center}.focus-mode .course-sidebar,.focus-mode .context-sidebar{display:none}.focus-mode .reader-main{padding-inline:8px}
/* 搜索和图像使用原生 dialog：可键盘关闭，焦点自动留在弹层内。 */
dialog{color:var(--ink);background:#fff;border:1px solid #dbdfe6;border-radius:12px;padding:0;box-shadow:0 20px 90px #1e242f20}dialog::backdrop{background:rgba(28,47,38,.4);backdrop-filter:blur(3px)}.search-dialog{width:min(680px,calc(100vw - 32px));margin:12vh auto auto;max-height:78dvh}.search-heading{display:flex;justify-content:space-between;align-items:center;margin:0;padding:15px 18px 4px 24px}.search-heading label{display:flex;gap:10px;align-items:center;font-size:13px;color:#657289}.search-heading svg{width:18px}.search-dialog>input{display:block;width:calc(100% - 48px);margin:14px 24px 0;border:1px solid #bdc3ce;background:#fbfcfd;border-radius:6px;padding:13px 14px;color:var(--ink);font-size:17px;outline-offset:1px}.search-status{font-size:12px;color:#78859c;padding:16px 24px 12px}.search-results{max-height:calc(78dvh - 209px);overflow:auto;padding:0 12px 12px;overscroll-behavior:contain;min-height:90px}.search-result{display:block;padding:14px 14px 15px;border-radius:6px;color:var(--ink);margin-bottom:3px}.search-result:hover,.search-result:focus{background:var(--accent-wash);color:var(--ink);outline:0}.search-result strong{display:block;font-size:14px;font-weight:600;line-height:1.7}.search-result span{display:block;font-size:11px;color:#68768d;margin:5px 0}.search-result p{font-size:12px;line-height:1.9;color:#68758c}.search-result mark{background:#dce0e7;color:#323c4d;padding:0 2px}.search-empty{padding:12px;font-size:14px;color:var(--muted)}.search-dialog>footer{display:flex;justify-content:space-between;background:#f6f7f9;border-top:1px solid var(--line);padding:12px 24px;color:#7c889e;font-size:10px}.image-viewer{width:min(1240px,96vw);max-width:96vw;height:94dvh;max-height:94dvh}.image-viewer[open]{display:flex;flex-direction:column;overflow:hidden}.image-viewer header{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:14px 20px;border-bottom:1px solid var(--line);flex-shrink:0;font-size:14px}.image-actions{display:flex;gap:8px}.image-viewer button{border:1px solid var(--line);background:var(--soft);padding:6px 14px;border-radius:5px;font-size:13px}.image-canvas{flex:1;min-width:0;min-height:0;overflow:auto;background:white}.image-canvas img{display:block;width:100%;max-width:none;height:100%;object-fit:contain;margin:auto}.image-canvas img.actual-size{width:auto;max-width:none;height:auto;margin:0}.image-viewer footer{padding:15px 20px;border-top:1px solid var(--line);max-height:22vh;overflow:auto;flex-shrink:0}.image-viewer footer p{font-size:12px;line-height:1.8;color:var(--muted)}.image-viewer footer a{font-size:11px;display:inline-flex;align-items:center;gap:5px;margin-top:5px}.image-viewer footer svg{width:12px;height:12px}.toast{position:fixed;left:50%;bottom:28px;transform:translate(-50%,14px);opacity:0;pointer-events:none;background:#363d4a;color:#fff;padding:10px 20px;border-radius:7px;font-size:13px;z-index:90;transition:.16s}.toast.visible{opacity:1;transform:translate(-50%,0)}
/* 关注入口：桌面二维码可扫描，手机保留原图与公众号名。 */
.community-section{padding:32px 0 38px;border-top:1px solid var(--line);display:flex;align-items:center;gap:32px}.community-section h2{font-size:17px;font-weight:600}.community-section p{font-size:13px;color:var(--muted);margin-top:8px}.community-section img{display:block;width:130px;height:130px;flex-shrink:0;background:#fff}.community-section .qr-link{flex-shrink:0;margin-left:auto}.community-section .qr-caption{font-size:10px;text-align:center;color:var(--muted);margin-top:7px}.community-mini{margin-top:18px}.community-mini summary{color:var(--accent);font-size:12px;cursor:pointer;width:fit-content}.community-mini .community-section{border:0;padding:20px 0 0;gap:20px}.community-mini h2{font-size:14px}.community-mini p{font-size:12px}.community-mini img{width:112px;height:112px}
@media(min-width:1500px){.reader-layout{grid-template-columns:240px minmax(0,760px) 190px;gap:58px}.header-inner{padding-inline:32px}}
@media(max-width:1180px){.reader-layout{grid-template-columns:220px minmax(0,760px);gap:38px}.context-sidebar{display:none}.home-hero{gap:42px}.header-inner{padding-inline:30px}.curriculum-layout{gap:38px;grid-template-columns:205px minmax(0,1fr)}.model-preview{padding:22px}.token-line{gap:5px}.token-line span{width:30px}.hero-copy h1{font-size:43px}.reader-main{max-width:760px}}
@media(max-width:860px){.page-width{width:calc(100% - 48px)}.header-inner{padding-inline:24px;gap:20px}.header-nav{gap:22px}.search-trigger kbd{display:none}.home-hero{gap:28px;padding-block:56px}.hero-copy h1{font-size:36px}.hero-copy>p{font-size:14px}.hero-actions{gap:18px;flex-wrap:wrap}.hero-actions .button{font-size:14px;padding:13px 17px}.model-preview{padding:18px 16px}.model-caption{font-size:11px}.token-line span{width:27px;height:32px;font-size:14px}.pipeline-row{gap:11px;padding:11px 12px}.pipeline-row>span:nth-child(2){font-size:12px}.pipeline-row small{font-size:9px}.pipeline-lesson{display:none}.pipeline-row svg{margin-left:auto}.model-pipeline:before{left:23px}.model-loop{margin-left:18px;font-size:10px}.curriculum-layout{grid-template-columns:1fr;gap:32px}.path-rail{position:static}.path-rail nav{grid-template-columns:repeat(4,1fr);gap:0}.path-rail nav a{border-left:0;border-top:2px solid var(--line);padding:12px 10px;display:block}.path-rail nav a.active,.path-rail nav a:hover{border-top-color:var(--accent)}.path-rail nav a span{display:block;margin-bottom:7px}.path-rail nav a strong{font-size:12px;display:block}.path-rail nav .icon{display:none}.guide-links{display:flex;gap:24px;padding:20px 10px 0}.guide-links a{gap:12px}.featured-experiments{gap:24px}.experiment-feature{display:block}.experiment-number{display:block;margin-bottom:14px}.reader-layout{display:block;padding-inline:28px}.reader-main{margin:auto;padding-top:28px}.course-sidebar{display:none}.js .menu-toggle{display:inline-flex!important}.js .menu-close{display:inline-flex!important}.menu-toggle{margin-left:-8px;margin-right:-10px}.article-page .header-nav a:first-child{display:none}.course-sidebar.mobile-open{display:block;position:fixed;top:76px;left:0;bottom:0;width:min(320px,86vw);height:calc(100dvh - 76px);z-index:50;background:white;border-right:1px solid var(--line);padding:22px 24px 40px;box-shadow:10px 0 30px #1e242f0c}.sidebar-scrim{position:fixed;inset:76px 0 0;background:#1a1f284a;z-index:40}.sidebar-stage>summary{font-size:14px;padding:10px 20px 12px 3px}.sidebar-stage>summary:after{top:17px}.lesson-link{font-size:14px;padding:10px 8px}.sidebar-heading{font-size:15px;margin-bottom:20px}.course-progress{font-size:12px}.lesson-number{font-size:12px}.focus-mode .reader-main{padding-inline:0}.focus-mode .menu-toggle{visibility:hidden}.article-page .search-trigger{margin-left:auto}.article-page .header-nav{margin-left:auto}.article-page .header-inner{gap:20px}}
@media(max-width:600px){html{scroll-padding-top:84px}.site-header{height:68px}.header-inner{padding-inline:20px;gap:14px}.brand{gap:8px}.brand strong{font-size:15px}.brand small{font-size:9px}.brand img{width:31px;height:31px}.header-nav{display:none}.js .search-trigger{display:flex!important;margin-left:auto;width:36px;height:36px;justify-content:center;padding:0;border:0;background:transparent}.search-trigger>span{display:none}.search-trigger .icon{width:21px;height:21px}.page-width{width:calc(100% - 40px)}.home-hero{grid-template-columns:1fr;padding-top:40px;padding-bottom:42px;gap:36px}.hero-copy h1{font-size:39px;line-height:1.3;letter-spacing:-.055em}.hero-copy>p{font-size:15px;margin-top:22px;line-height:1.9}.hero-actions{margin-top:26px;gap:24px}.hero-copy p.hero-note{margin-top:20px;font-size:11px}.model-preview{padding:20px 23px}.model-caption{font-size:12px}.token-line{gap:6px;margin:23px 0 20px}.token-line span{width:32px;height:34px;font-size:15px}.pipeline-row{padding:12px 14px;gap:14px}.pipeline-row>span:nth-child(2){font-size:13px}.pipeline-row small{font-size:10px}.pipeline-lesson{display:block}.pipeline-row svg{margin-left:0}.model-pipeline:before{left:25px}.model-loop{margin-left:20px;font-size:10px}.curriculum-section{padding-top:34px;padding-bottom:42px}.section-heading{gap:20px;margin-bottom:28px;align-items:flex-start}.section-heading h2{font-size:23px;line-height:1.5}.section-heading p{font-size:12px;line-height:1.8;margin-top:8px}.home-progress{font-size:10px;margin-top:5px}.home-progress strong{font-size:17px;white-space:nowrap}.path-rail nav{grid-template-columns:1fr 1fr;gap:8px}.path-rail nav a{border-top:0;border-left:2px solid var(--line);padding:10px 12px}.path-rail nav a.active,.path-rail nav a:hover{border-left-color:var(--accent)}.path-rail nav a strong{font-size:12px}.guide-links{justify-content:space-between;gap:12px;padding:18px 2px 0}.guide-links a{font-size:11px;gap:8px}.catalog-stage>header{gap:11px;padding-bottom:17px}.stage-marker{font-size:27px;width:36px}.catalog-stage h3{font-size:18px}.catalog-stage header p{font-size:11px;line-height:1.8}.lesson-range{display:none}.course-row{gap:10px;padding:17px 3px 17px 0;align-items:baseline}.row-number{width:33px;font-size:11px}.row-content strong{font-size:14px;line-height:1.8}.row-content small{font-size:11px;line-height:1.9}.course-row>svg{width:13px;align-self:center}.stage-outcome{font-size:10px;line-height:1.8;align-items:flex-start}.stage-outcome svg{margin-top:2px}.catalog-stage{margin-bottom:34px}.featured-experiments{grid-template-columns:1fr;gap:0}.experiment-feature{display:flex;gap:22px;padding:24px 0}.experiment-number{margin:0;font-size:28px}.experiment-feature h3{font-size:17px}.experiment-feature p{font-size:12px}.text-link{margin-top:14px}.experiments-section{padding-top:35px;padding-bottom:24px}.experiments-section .section-heading{display:block}.section-count{display:block;font-size:11px;margin-top:14px}.more-experiments>div{grid-template-columns:1fr}.more-experiments a{padding:15px 0;font-size:12px}.closing-section{display:block;padding-block:35px}.closing-section h2{font-size:22px}.closing-section p{font-size:13px;line-height:1.9}.closing-section .button{margin-top:22px;font-size:13px}.site-footer{display:block;padding-block:22px;font-size:10px}.site-footer span{display:block;margin:5px 0}.reader-layout{padding-inline:21px}.reader-main{padding-top:22px}.article-context{margin-bottom:23px;font-size:10px;gap:8px}.focus-toggle{font-size:10px}.article-page .header-inner{gap:13px}.menu-toggle{width:30px;margin-right:0;margin-left:-7px}.course-sidebar.mobile-open{top:68px;height:calc(100dvh - 68px)}.sidebar-scrim{top:68px}#article-body h1{font-size:27px;line-height:1.55;margin-bottom:18px}#article-body h1+p{font-size:10px;line-height:1.8;margin-bottom:26px}#article-body p,#article-body li{font-size:calc(var(--body-size) - 1px);line-height:1.95}#article-body h2{font-size:22px;margin-top:40px;margin-bottom:19px}#article-body h3{font-size:19px;margin-top:30px}#article-body p{margin:19px 0}#article-body ul,#article-body ol{padding-left:23px}#article-body li{margin:10px 0;padding-left:1px}#article-body pre{font-size:12px;padding:15px}#article-body .code-block pre{padding:15px 16px 18px}.code-toolbar{padding:8px 12px 8px 16px}#article-body th,#article-body td{padding:10px 9px}#article-body table{font-size:13px}#article-body details{padding:13px 15px}#article-body summary{font-size:14px}#article-body details p{font-size:calc(var(--body-size) - 2px)}.lesson-finish{gap:16px;flex-wrap:wrap;margin-top:38px;padding-top:24px}.complete-button{font-size:12px}.source-link{font-size:10px}.chapter-nav{gap:12px;margin-top:28px}.chapter-nav a{padding:14px 13px}.chapter-nav strong{font-size:12px}.chapter-nav a>span{font-size:10px}.reader-footer{margin-top:30px;font-size:10px}.search-dialog{margin-top:7vh;max-height:86dvh}.search-results{max-height:calc(86dvh - 210px)}.search-heading{padding-left:20px}.search-dialog>input{width:calc(100% - 40px);margin-inline:20px;font-size:16px}.search-status{padding-inline:20px}.search-dialog>footer{padding-inline:20px}.image-viewer{border-radius:7px}.image-viewer header{padding:12px;font-size:12px}.image-viewer button{padding:6px 10px;font-size:12px}.image-viewer footer{padding:12px 14px}.community-section{gap:18px;align-items:flex-start;padding-block:26px}.community-section h2{font-size:15px}.community-section p{font-size:12px;line-height:1.85}.community-section img{width:108px;height:108px;max-width:none}.community-section .qr-caption{font-size:9px}.community-mini .community-section{gap:15px}.community-mini img{width:100px;height:100px}}
@media(prefers-reduced-motion:reduce){*,*:before,*:after{scroll-behavior:auto!important;transition:none!important;animation:none!important}}
@media print{.site-header,.course-sidebar,.context-sidebar,.article-context,.lesson-finish,.chapter-nav,.site-footer,.community-mini,.reading-progress,.code-toolbar,.image-open:after,.toast,.search-dialog,.image-viewer{display:none!important}.reader-layout,.reader-main{display:block!important;max-width:none!important;padding:0!important}#article-body h1{font-size:26pt}#article-body h2{break-after:avoid}#article-body pre{white-space:pre-wrap;font-size:10pt}#article-body code{white-space:pre-wrap!important}#article-body img{break-inside:avoid;max-width:95%}#article-body p,#article-body li{font-size:12pt}#article-body details{break-inside:avoid}.reader-footer{font-size:9pt}body{color:#000}}
.mobile-context{display:none}
@media(max-width:1180px){.mobile-context{display:block;margin:0 0 25px;padding:13px 16px;border:1px solid var(--line);border-radius:6px;background:#fbfcfd}.mobile-context summary{cursor:pointer;font-size:12px;list-style:disclosure-closed;margin:0}.mobile-context details[open]>summary{list-style:disclosure-open;margin-bottom:13px}.mobile-context .reading-route a{font-size:12px;padding-block:7px}.mobile-context .lesson-experiments{padding-top:15px;margin-top:16px}.mobile-context .lesson-experiments h2{font-size:12px;font-weight:500}.mobile-context .lesson-experiments a{font-size:12px}.focus-mode .mobile-context{display:none}}
@media print{.mobile-context{display:none!important}}
/* 双主题共享同一组教材语义色；原始图表保持原色，避免翻转正负与输入/参数含义。 */
.header-controls{display:flex;gap:12px;align-items:center}.language-switch{color:var(--muted);font:500 11px var(--sans);padding:8px 4px}.theme-toggle{flex-shrink:0;color:var(--muted)}.theme-dark-icon{display:none}.theme-toggle svg{width:18px;height:18px}.js .theme-toggle{display:inline-flex!important}.home-hero{position:relative;isolation:isolate}.home-hero:before{content:'';position:absolute;inset:0;left:calc((100% - 100vw)/2);right:calc((100% - 100vw)/2);z-index:-1;background:linear-gradient(110deg,#e7eaef 0%,#eff1f4 52%,#e2e5eb 100%)}.home-page .site-header{background:#f4f6f8f7;border-bottom-color:#d2d6de}.home-hero .model-preview{background:#f7f8f9d9;border-color:#bbc2cd;box-shadow:0 16px 48px #262e3c0b}.hero-copy>p{color:#515b6d}.hero-copy p.hero-note{color:#5f6c81}.curriculum-section{border-top:0}.experiments-section{background:#ebedf1;border-color:#d4d8df}.beginning-links{padding:0 18px 24px}.guide-stage{background:#f1f3f6;border-left:2px solid #a0a9b8;padding:21px 24px;margin-bottom:38px;border-radius:0 7px 7px 0}.guide-stage h3{font:550 16px var(--display)}.guide-stage>p{font-size:12px;color:var(--muted);margin-top:9px}.guide-stage>div{display:flex;gap:30px;margin-top:15px}.guide-stage a{font-size:13px;display:flex;align-items:center;gap:20px}.guide-stage a svg{width:15px;height:15px}.ending-stage{margin-top:36px;margin-bottom:0}.home-page .header-nav{gap:26px}.home-page .header-inner{gap:25px}.header-controls .search-trigger kbd{margin-left:8px}
[data-theme=dark]{color-scheme:dark;--paper:#22272e;--ink:#cdd9e5;--muted:#adbac7;--accent:#7dc6a2;--accent-dark:#a2dcbd;--accent-wash:#2a3d33;--blue:#87b5e4;--purple:#c2a3df;--line:#444c56;--soft:#2d333b}
[data-theme=dark] .site-header,[data-theme=dark] .home-page .site-header{background:#151a22f5;border-color:#373e4b}
[data-theme=dark] .home-hero:before{background:linear-gradient(110deg,#1f2530 0%,#242b38 56%,#293241 100%)}
[data-theme=dark] .hero-copy>p,[data-theme=dark] .hero-copy p.hero-note{color:#b7beca}
[data-theme=dark] .home-hero .model-preview{background:#1d232d;border-color:#464f5f;box-shadow:0 18px 48px #00000015}
[data-theme=dark] .model-caption{color:#c1c7d2}[data-theme=dark] .model-label{color:#8792a6}
[data-theme=dark] .token-line span{background:#262e3b;border-color:#4c5667;color:#d5d9e0}[data-theme=dark] .token-line .next-token{background:#313b4d;color:#bdc4cf}
[data-theme=dark] .pipeline-row{background:#232b38;border-color:#414957;color:#e1e4ea;box-shadow:none}[data-theme=dark] .pipeline-row:hover{border-color:#97a1b2}
[data-theme=dark] .model-pipeline:before{background:#545f72}[data-theme=dark] .pipeline-dot{background:#1e242f}[data-theme=dark] .pipeline-lesson,[data-theme=dark] .model-loop{color:#a0a9b9}
[data-theme=dark] .header-nav a,[data-theme=dark] .article-context,[data-theme=dark] .focus-toggle,[data-theme=dark] .source-link{color:#a8b0be}
[data-theme=dark] .search-trigger{background:#232b38;border-color:#3e4755;color:#bac1cc}[data-theme=dark] .search-trigger kbd{background:#1c222d;border-color:#475161;color:#9aa4b5}
[data-theme=dark] .button{background:#232a36;color:#d2d6de;border-color:#4b5566}[data-theme=dark] .button.primary{background:#a4adbc;color:#1e242e;border-color:#a4adbc;box-shadow:none}[data-theme=dark] .button.primary:hover{background:#b7beca}
[data-theme=dark] .stage-marker,[data-theme=dark] .experiment-number{color:#7c899f}[data-theme=dark] .row-number,[data-theme=dark] .path-rail nav a span,[data-theme=dark] .lesson-range{color:#9ca5b5}
[data-theme=dark] .course-row{border-color:#2a3342}[data-theme=dark] .course-row:hover,[data-theme=dark] .lesson-link:hover{background:#232a37}
[data-theme=dark] .guide-stage{background:#232a37;border-color:#566175}[data-theme=dark] .stage-outcome{color:#a1aab9}
[data-theme=dark] .experiments-section{background:#1e242e;border-color:#3c4350}[data-theme=dark] .experiment-feature,[data-theme=dark] .more-experiments{border-color:#475060}
[data-theme=dark] .more-experiments a,[data-theme=dark] .site-footer{color:#a9b2c0}
[data-theme=dark] .course-sidebar{scrollbar-color:#3d4552 transparent}[data-theme=dark] .course-sidebar.mobile-open{background:#1b2029}
[data-theme=dark] .sidebar-stage>summary,[data-theme=dark] .sidebar-heading a,[data-theme=dark] .context-sidebar h2{color:#bbc2cd}
[data-theme=dark] .lesson-link{color:#b1b8c5}[data-theme=dark] .lesson-link[aria-current]{color:#c3c9d3;background:#2b3443}
[data-theme=dark] .reading-route a{color:#a0a9b8}[data-theme=dark] .reading-route a.active{color:#bfc5d0;background:linear-gradient(90deg,#293241,transparent)}
[data-theme=dark] .reading-route summary{color:#b8bfca}[data-theme=dark] .lesson-experiments a,[data-theme=dark] .lesson-goal,[data-theme=dark] .reading-settings>span{color:#a1aaba}
[data-theme=dark] .font-controls button{background:#212834;color:#bfc5d0}[data-theme=dark] .font-controls button:hover{background:#2e3848}
[data-theme=dark] .font-controls span{color:#9ca5b5}[data-theme=dark] .mobile-context{background:#222935}
[data-theme=dark] #article-body strong{color:#b3bac7}[data-theme=dark] #article-body p code,[data-theme=dark] #article-body li code{background:#262e3b;color:#bfc5d0}
[data-theme=dark] #article-body pre,[data-theme=dark] #article-body .code-block{background:#1e242e;border-color:#3c4452}
[data-theme=dark] #article-body pre code{color:#d6dae1}[data-theme=dark] .code-toolbar{border-color:#3c4451;color:#a1aaba}
[data-theme=dark] .code-copy{background:#293241;border-color:#4d5768;color:#b9c0cc}[data-theme=dark] .token-keyword{color:#cfaddc}[data-theme=dark] .token-string{color:#b6bdc9}[data-theme=dark] .token-number{color:#e1bb91}[data-theme=dark] .token-comment{color:#919bad}[data-theme=dark] .token-builtin{color:#9ec7e9}
[data-theme=dark] #article-body th{background:#272f3c}[data-theme=dark] #article-body details{background:#202631;border-color:#424b5a}
[data-theme=dark] #article-body summary{color:#bdc3ce}[data-theme=dark] #article-body details.optional>summary{color:#c7afda}[data-theme=dark] #article-body blockquote{color:#b1b9c6;border-color:#637086}
[data-theme=dark] #article-body .image-open{border:1px solid #4e5869;border-radius:7px;background:#fff;overflow:hidden;padding:8px 8px 0}[data-theme=dark] #article-body .image-open:after{color:#556074;padding:5px 8px 8px;margin:0}
[data-theme=dark] .complete-button[aria-pressed=false]{background:#2b3444;color:#c3c9d3;border-color:#505b6d}[data-theme=dark] .complete-button[aria-pressed=true]{background:#9ea7b7;color:#202732}
[data-theme=dark] dialog{background:#1b212b;border-color:#4e5869}[data-theme=dark] dialog::backdrop{background:#0a0c10bf}
[data-theme=dark] .search-heading label{color:#abb3c1}[data-theme=dark] .search-dialog>input{background:#262e3c;border-color:#5c687d;color:#e0e4ea}
[data-theme=dark] .search-status,[data-theme=dark] .search-result span,[data-theme=dark] .search-result p{color:#a0a9b8}
[data-theme=dark] .search-result:hover,[data-theme=dark] .search-result:focus{background:#2e3747}[data-theme=dark] .search-result mark{background:#4b5566;color:#e8ebef}
[data-theme=dark] .search-dialog>footer{background:#232b38;color:#9ea8b8}[data-theme=dark] .image-viewer button{color:#cbd0d8;border-color:#485161;background:#2a3342}
[data-theme=dark] .theme-dark-icon{display:inline-flex}[data-theme=dark] .theme-light-icon{display:none}
html[lang=en]{--sans:'Segoe UI','Helvetica Neue',Arial,'PingFang SC',sans-serif;--display:'Segoe UI','Helvetica Neue',Arial,sans-serif}
html[lang=en] .hero-copy h1{font-size:clamp(34px,3.6vw,50px);letter-spacing:-.045em;line-height:1.16}html[lang=en] .hero-copy>p{font-size:16px;line-height:1.8}html[lang=en] .desktop-break{display:none}html[lang=en] .header-nav{gap:22px}html[lang=en] .header-inner{gap:22px}html[lang=en] .search-trigger kbd{display:none}html[lang=en] .sidebar-stage>summary{font-size:11px}html[lang=en] .lesson-link{font-size:12px}html[lang=en] .reading-route a{font-size:12px}html[lang=en] .section-heading h2{font-size:30px}html[lang=en] #article-body p,html[lang=en] #article-body li{line-height:1.85}html[lang=en] .pipeline-row>span:nth-child(2){font-size:13px}html[lang=en] #article-body .image-open:after{content:'Enlarge figure'}
@media(max-width:1180px){.header-inner{gap:22px}.header-nav{gap:22px}.header-controls{gap:7px}.search-trigger kbd{display:none}.js .search-trigger{width:36px;height:36px;padding:0;justify-content:center;border:0;background:transparent}.search-trigger>span{display:none}html[lang=en] .header-nav{gap:20px}html[lang=en] .hero-copy h1{font-size:39px}}
@media(max-width:860px){.header-controls{margin-left:auto}.header-nav{margin-left:auto}.beginning-links{padding:0 10px 20px;justify-content:flex-start}.guide-stage{margin-bottom:30px}.home-page .header-nav{gap:18px}.home-page .header-inner{gap:18px}html[lang=en] .header-nav{display:none}html[lang=en] .hero-copy h1{font-size:34px}}
@media(max-width:600px){.header-controls{gap:7px}.language-switch{font-size:11px}.theme-toggle{width:31px;height:34px}.header-controls .search-trigger{margin:0}.home-hero{padding-block:39px 36px}.home-hero:before{background:linear-gradient(155deg,#e7eaef,#eceef2)}.guide-stage{padding:18px 19px}.guide-stage h3{font-size:15px}.guide-stage>p{font-size:11px;line-height:1.8}.guide-stage a{font-size:12px;gap:12px}.guide-stage>div{gap:28px}.beginning-links{padding:0 2px 20px;gap:26px;justify-content:flex-start}.header-inner,.article-page .header-inner{gap:10px}.brand strong{font-size:14px}.brand small{font-size:8px}.brand img{width:29px;height:29px}.article-page .brand img{display:none}.article-page .header-controls{gap:8px}.theme-toggle svg{width:17px;height:17px}html[lang=en] .hero-copy h1{font-size:41px;line-height:1.15}html[lang=en] .hero-copy>p{font-size:15px}html[lang=en] .section-heading h2{font-size:25px}html[lang=en] .pipeline-row>span:nth-child(2){font-size:12px}html[lang=en] .model-loop{font-size:11px}html[lang=en] .sidebar-stage>summary{font-size:13px}}
@media print{body{background:white!important;color:black!important}.header-controls{display:none!important}}
/* Full-bleed hero paint must not create a horizontal scroll area. */
.home-page{overflow-x:clip}
.home-hero:before{display:none}.hero-band{background:linear-gradient(110deg,#e7eaef 0%,#eff1f4 52%,#e2e5eb 100%)}[data-theme=dark] .hero-band{background:linear-gradient(110deg,#1f2530 0%,#242b38 56%,#293241 100%)}

/* Reading-first palette: neutral paper and rails, blue only for actions and location. */


.hero-band{background:#f0f3f7}[data-theme=dark] .hero-band{background:#1b2635}
.home-page .site-header{background:#f8f9fbf7}.home-hero .model-preview{background:#ffffff;border-color:#d7e0e9;box-shadow:0 12px 36px #243c5908}
.hero-copy>p{color:#526174}.hero-copy p.hero-note{color:#69788b}
.pipeline-dot.teal{color:#187b79}.pipeline-dot.blue{color:#3267a4}.pipeline-dot.purple{color:#8056a5}
.header-nav a{font-size:14px;color:#59677a}.brand small{color:#66758a}
.lesson-link{font-size:13px;color:#586779}.sidebar-stage>summary{font-size:12px;color:#3f5065}.reading-route a{font-size:12px;color:#69788a}
.context-sidebar h2,.reading-route summary{font-size:12px;color:#42536a}.reading-settings>span,.lesson-goal{font-size:12px;color:#6c7c90}
#article-body strong{color:#2b486e}#article-body p code,#article-body li code{color:#34597f;background:#eef2f7}
#article-body h1+p{color:#718095}#article-body .image-open:after{color:#697c92}
.experiments-section{background:#f1f4f8;border-color:#dfe5ed}
[data-theme=dark] .site-header,[data-theme=dark] .home-page .site-header{background:#121b27f5;border-color:#344258}
[data-theme=dark] .home-hero .model-preview{background:#202d3e;border-color:#435570}
[data-theme=dark] .pipeline-row{background:#26374b;border-color:#405671;color:#e0e8f2}
[data-theme=dark] .hero-copy>p,[data-theme=dark] .hero-copy p.hero-note{color:#b3c1d4}
[data-theme=dark] .button.primary{background:#93b6e1;color:#172f4e;border-color:#93b6e1}
[data-theme=dark] .button.primary:hover{background:#abc8ed}
[data-theme=dark] .pipeline-dot.teal{color:#86c9bd}[data-theme=dark] .pipeline-dot.blue{color:#9cbfe9}[data-theme=dark] .pipeline-dot.purple{color:#c7a6e5}
[data-theme=dark] #article-body strong{color:#a9c6e9}[data-theme=dark] #article-body p code,[data-theme=dark] #article-body li code{color:#bdd1eb;background:#25374e}
[data-theme=dark] .experiments-section{background:#1b2635;border-color:#344258}
[data-theme=dark] .lesson-link,[data-theme=dark] .reading-route a{color:#b0bfd1}
[data-theme=dark] .reading-route a.active{color:#b9d3f3;background:linear-gradient(90deg,#2b3d58,transparent)}
[data-theme=dark] .lesson-link[aria-current]{color:#b9d3f3;background:#2a3e59}
[data-theme=dark] .search-result mark{background:#476488;color:#f0f5fc}
@media(max-width:600px){.hero-copy p.hero-note{font-size:12px}.article-context{font-size:11px}.row-content small{font-size:12px}.catalog-stage header p{font-size:12px}.course-row{padding-block:18px}.guide-stage>p{font-size:12px}.stage-outcome{font-size:11px}.hero-copy h1{font-size:38px}}
/* Final reading palette, informed by GitHub Primer Light / Dark Dimmed. */


.hero-copy h1 em{color:#345d8a}[data-theme=dark] .hero-copy h1 em{color:#96bde9}
.hero-band{background:#eff2f5}[data-theme=dark] .hero-band{background:#2d333b}
[data-theme=dark] .site-header,[data-theme=dark] .home-page .site-header{background:#22272ef5;border-color:#444c56}
[data-theme=dark] .home-hero .model-preview{background:#282e36;border-color:#4d5762}
[data-theme=dark] .pipeline-row{background:#323b46;border-color:#4d5968;color:#d9e3ed}
[data-theme=dark] .course-sidebar.mobile-open,[data-theme=dark] dialog{background:#22272e}
[data-theme=dark] .guide-stage,[data-theme=dark] .mobile-context,[data-theme=dark] .experiments-section{background:#2d333b;border-color:#444c56}
[data-theme=dark] .token-line span{background:#343e4b;border-color:#536273;color:#d2dfec}
[data-theme=dark] .button.primary{background:#316dca;color:#fff;border-color:#4184e4}[data-theme=dark] .button.primary:hover{background:#4184e4}
[data-theme=dark] #article-body pre,[data-theme=dark] #article-body .code-block{background:#2d333b;border-color:#444c56}
[data-theme=dark] #article-body pre code{color:#cdd9e5}[data-theme=dark] .code-toolbar{border-color:#444c56;color:#adbac7}
[data-theme=dark] #article-body p code,[data-theme=dark] #article-body li code{color:#cdd9e5;background:#343c47}
[data-theme=dark] #article-body strong{color:#dbe7f3}[data-theme=dark] #article-body details{background:#2b333d;border-color:#444c56}
[data-theme=dark] .token-keyword{color:#dcbdfb}[data-theme=dark] .token-string{color:#96d0ff}[data-theme=dark] .token-number{color:#6cb6ff}[data-theme=dark] .token-comment{color:#a2adba}
[data-theme=dark] .search-trigger,[data-theme=dark] .search-dialog>input{background:#2d333b;border-color:#545d68}
[data-theme=dark] .search-result:hover,[data-theme=dark] .search-result:focus{background:#344154}
[data-theme=dark] .font-controls button{background:#2d333b}[data-theme=dark] .search-dialog>footer{background:#2d333b}
#article-body strong{color:var(--ink)}.lesson-goal,.reading-settings>span,.source-link,.reading-route a{color:var(--muted)}

.experiment-viewer{width:min(1380px,96vw);height:94dvh;max-width:96vw;max-height:94dvh;overflow:hidden;background:var(--paper)}
.experiment-viewer[open]{display:flex;flex-direction:column}.experiment-viewer>header{display:flex;align-items:center;justify-content:space-between;gap:20px;padding:13px 20px;border-bottom:1px solid var(--line);flex-shrink:0}.experiment-viewer>header strong{font-size:14px;font-weight:500}.experiment-viewer>header>div{display:flex;align-items:center;gap:20px}.experiment-viewer>header a{font-size:12px;display:flex;align-items:center;gap:6px}.experiment-viewer .button{font-size:12px;padding:8px 12px;gap:8px}.experiment-viewer .icon{width:14px;height:14px}.experiment-viewer iframe{border:0;width:100%;flex:1;min-height:0;background:#fff}
@media(max-width:600px){.experiment-viewer{width:100vw;max-width:100vw;height:100dvh;max-height:100dvh;border-radius:0;margin:0;border:0}.experiment-viewer>header{gap:12px;padding:12px}.experiment-viewer>header strong{font-size:12px}.experiment-viewer>header>div{gap:12px}.experiment-viewer>header a{font-size:10px}.experiment-viewer .button{font-size:11px;padding:7px 9px}.experiment-viewer>header strong{max-width:45%;line-height:1.5}}
@media print{.experiment-viewer{display:none!important}}

/* Account green is an accent; neutral reading surfaces carry the page. */
.hero-copy h1 em{color:#2f7d4a}[data-theme=dark] .hero-copy h1 em{color:#9bc9ae}
.button.primary{background:#2f7d4a;border-color:#2f7d4a}.button.primary:hover{background:#245f39}
[data-theme=dark] .button.primary{background:#34734f;border-color:#57986d;color:#fff}[data-theme=dark] .button.primary:hover{background:#3e875e}
.lesson-link[aria-current]{color:var(--accent-dark);background:var(--accent-wash)}[data-theme=dark] .lesson-link[aria-current]{color:#a6d7ba;background:#2d4236}
.reading-route a.active{color:var(--accent);background:linear-gradient(90deg,#f0f7f2,transparent)}[data-theme=dark] .reading-route a.active{color:#9bc9ae;background:linear-gradient(90deg,#2d4236,transparent)}
.path-rail nav a.active,.path-rail nav a:hover{background:var(--accent-wash);border-left-color:var(--accent)}
.lesson-video{margin:20px 0 28px;border:1px solid var(--line);border-radius:6px;background:var(--soft);color:var(--muted)}
.video-pending{padding:12px 15px;display:flex;justify-content:space-between;align-items:center;gap:18px;font-size:12px}.video-pending>span{display:flex;align-items:center;gap:8px}.video-pending .icon{width:15px;height:15px}.video-pending small{font-size:11px;color:var(--muted);white-space:nowrap}
#article-body .lesson-video{margin:20px 0 28px}#article-body details.video-ready{padding:0;background:var(--soft);border-color:var(--line)}
.video-ready summary,#article-body .video-ready summary{display:flex;align-items:center;gap:10px;cursor:pointer;padding:13px 16px;font-size:13px;color:var(--accent);list-style:none;margin:0;border:0}
.video-ready summary::-webkit-details-marker{display:none}.video-language{font-size:10px;color:var(--muted);margin-left:auto}.video-ready video{display:block;width:100%;aspect-ratio:16/9;background:#141414;border-top:1px solid var(--line);border-radius:0 0 6px 6px}
#article-body .video-ready[open]>summary{margin:0;padding:13px 16px;border:0}
@media print{.lesson-video{display:none!important}}
#article-body h1+p,.code-toolbar,.reader-footer,.sidebar-note{color:var(--muted)}
.token-comment{color:#626e7e}[data-theme=dark] .token-comment{color:#adbac7}
[data-theme=dark] .progress-track{background:#444c56}
/* One header offset only: section links land just below the sticky navigation. */
html{scroll-padding-top:76px}#article-body h2,#article-body h3{scroll-margin-top:24px}.catalog-stage{scroll-margin-top:30px}#curriculum,#experiments{scroll-margin-top:24px}
@media(max-width:600px){html{scroll-padding-top:68px}}

/* 书籍入口与正文内实验：读到解释即可动手，不依赖侧栏。 */
.book-eyebrow{font:600 12px/1.8 var(--mono);letter-spacing:.09em;color:var(--accent);margin-bottom:20px}
.stage-index,.stage-marker{white-space:nowrap;font-size:11px!important;width:auto!important;min-width:54px}
.inline-experiment{margin:32px 0;padding:0;border:1px solid var(--line);border-left:4px solid var(--accent);border-radius:8px;background:var(--soft);overflow:hidden}
.inline-experiment summary{padding:20px;cursor:pointer;color:var(--ink)}
.inline-experiment summary span{font-weight:650}.inline-experiment summary small{display:block;color:var(--muted);font-size:14px;margin-top:6px}
#article-body .inline-experiment p{margin:0;padding:0 20px 16px;font-size:14px}
.inline-experiment iframe{display:block;border:0;background:white;width:100%;height:680px}
.downloads-section{padding-block:50px 70px;border-top:1px solid var(--line)}
.downloads-section p{color:var(--muted);margin-top:16px}.download-links{display:flex;gap:16px;flex-wrap:wrap;margin-top:24px}.download-note{font-size:13px}
@media(max-width:700px){.inline-experiment iframe{height:72vh}.brand small{max-width:150px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.hero-actions{flex-wrap:wrap}}
@media print{.inline-experiment iframe{display:none}.inline-experiment{break-inside:avoid}}

/* SVG 横向版只在有足够阅读宽度时使用；手机恢复原图。 */
#article-body .wide-figure{display:block;width:100%;margin:26px auto}
#article-body .wide-figure img{width:100%;margin:0}
#article-body .wide-figure-button{width:100%;max-width:none}
#article-body .wide-figure-button picture{margin:0}
#article-body .motion-figure{margin:26px 0;border:1px solid var(--line);border-radius:8px;padding:14px 18px;background:var(--soft)}
.motion-figure summary{cursor:pointer;color:var(--accent);font-size:15px}
#article-body .motion-figure img{max-width:380px;width:100%;margin:18px auto}
@media(min-width:900px){#article-body>p>img,#article-body .image-open:not(.wide-figure-button){max-width:520px}#article-body .wide-figure img{max-width:none}}
@media(max-width:899px){#article-body .wide-figure-button{max-width:100%}#article-body .wide-figure img{max-width:100%}}

/* Course navigation follows the Hello LLM reading system. */
.course-preview .model-pipeline{margin-top:24px}.course-preview .model-pipeline:before{display:none}
.course-preview .model-caption{font-size:14px}.pipeline-note{font-size:12px;color:var(--muted);margin-top:22px;line-height:1.8}
.course-number{flex:0 0 30px;color:#87919f;font:12px var(--mono)}.course-title{flex:1;min-width:0;font-size:14px;line-height:1.8}
.course-row-arrow{flex:0 0 18px;color:var(--muted)}.course-row-arrow .icon{width:15px;height:15px}
.course-row{color:var(--ink)}.course-row:hover{color:var(--accent)}
.experiment-features{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:44px}
.experiments-section{border-top:1px solid var(--line);padding-block:54px 70px}
.practice-link{padding-block:26px;border-top:1px solid var(--line);font-size:13px}.practice-link a{display:flex;gap:9px;align-items:center}
.license-page{max-width:860px;padding-block:64px 100px}.license-page #article-body{max-width:none}.license-page h1{margin-bottom:32px}
.site-footer strong{margin-right:18px}.mermaid{overflow-x:auto!important;background:var(--soft)!important;border:1px solid var(--line);border-radius:8px;padding:20px!important;margin:28px 0!important;text-align:center}.mermaid svg{max-width:100%;height:auto}
.header-inner{gap:24px}.brand strong{letter-spacing:0}.sidebar-stage>summary{line-height:1.7}.lesson-link>span:nth-child(2){line-height:1.7}
@media(max-width:800px){.experiment-features{grid-template-columns:1fr;gap:24px}.course-title{font-size:13px}}
@media(max-width:600px){.header-inner{gap:10px}.brand small{max-width:160px}.brand strong{font-size:14px}.site-footer a{display:inline-block;margin-top:12px}.hero-copy h1{font-size:36px}.course-row{align-items:center}}

/* Course articles start with prose, rather than a metadata line. */
#article-body h1+p{font-size:var(--body-size);line-height:2;color:var(--ink);margin:24px 0}
@media(max-width:600px){#article-body h1+p{font-size:var(--body-size);line-height:1.95;margin:19px 0}}

.community-mini>summary{padding-block:8px}

/* Keep the zoom action discoverable on touch screens. */
.image-open::after{content:"放大查看";display:block;text-align:right;padding:5px 2px;color:var(--muted);font:12px/1.5 var(--sans)}

/* 阅读工具在手机、平板和专注模式中保持可用。 */
.article-context{flex-wrap:wrap;row-gap:14px}
.reading-tools{align-items:center;gap:10px;margin-left:auto;flex-shrink:0}
.js .reading-tools{display:flex!important}
.reading-tools .font-controls{display:flex;width:auto;margin:0;border-radius:6px}
.reading-tools .font-controls button{width:44px;height:44px;flex-shrink:0;background:var(--paper);color:var(--ink);font-size:14px}
.reading-tools .font-controls button:hover{background:var(--soft)}
.reading-tools .font-controls span{width:38px;color:var(--muted);font-size:12px}
.reading-tools .focus-toggle{min-height:44px;padding:0 10px;border:1px solid var(--line);border-radius:6px;font-size:12px;color:var(--muted)}
.reading-tools .focus-toggle:hover{background:var(--soft)}
.reading-tools .focus-toggle[aria-pressed=true]{color:var(--accent)}
.icon-button,.js .search-trigger{min-width:44px;min-height:44px;flex-shrink:0}
.header-controls{flex-shrink:0}
.code-copy{min-height:44px;padding-inline:12px;font-size:12px}
.lesson-link,.reading-route a,.sidebar-stage>summary{font-size:13px}
.hero-actions{flex-wrap:wrap;gap:12px 22px}
.hero-secondary{display:inline-flex;align-items:center;min-height:44px}
@media(max-width:600px){
 .header-inner,.article-page .header-inner{padding-inline:16px;gap:8px}
 .brand{min-width:0;flex-shrink:1}.brand strong{white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
 .brand>span{min-width:0}.header-controls,.article-page .header-controls{gap:4px}
 .article-context{font-size:12px;margin-bottom:24px}.article-context>span{flex-basis:100%}
 .reading-tools{margin-left:0}.lesson-link,.sidebar-stage>summary{font-size:14px}
}

.image-viewer button{min-height:44px}