:root{--paper:#fff;--side:#f7f7f5;--ink:#242424;--muted:#777773;--line:#e8e8e5;--soft:#f1f1ee;--accent:#eef5f0;--green:#386449;--sidebar:236px;font-family:-apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei",sans-serif;color:var(--ink);font-size:14px;background:var(--paper);font-synthesis:none}
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h1{font-size:28px;font-weight:500}.list-intro p{margin-top:12px;font-size:13px;color:var(--muted)}
/* The reading view uses a quiet article column and a persistent outline. */
.lesson-page{max-width:1140px;margin:0 auto;padding:27px 50px 90px}.lesson-breadcrumb{font-size:11px;display:flex;align-items:center;gap:10px;color:#919189;flex-wrap:wrap}.lesson-breadcrumb .icon{width:13px;height:13px}.lesson-breadcrumb a:hover{color:#282828}.lesson-layout{display:grid;grid-template-columns:minmax(0,1fr) 165px;gap:58px;margin-top:42px}.lesson-header .eyebrow{font:10px ui-monospace,SFMono-Regular,monospace;letter-spacing:.6px;color:#8f8f86}.lesson-header h1{font-size:34px;line-height:1.35;font-weight:550;letter-spacing:-.5px;margin:13px 0 12px}.lesson-subtitle{font-size:13px;line-height:1.9;color:#81817a}.lesson-pills{display:flex;gap:9px;flex-wrap:wrap;margin:18px 0}.lesson-pills span{font-size:10px;color:#7e7e75;background:#f5f5f2;border-radius:5px;padding:5px 8px}.lesson-pills .preview-pill{color:#57745b;background:#eff4ed}.lesson-cover{height:237px;position:relative;background:#f5f6f2;border-radius:12px;display:flex;align-items:center;justify-content:center;margin-top:27px;overflow:hidden}.lesson-cover .visual{height:94%;width:84%;object-fit:contain;mix-blend-mode:multiply}.lesson-cover .gear{height:94%;width:94%}.lesson-cover .cover-caption{position:absolute;bottom:14px;left:17px;font-size:9px;color:#92968b}.lesson-cover .course-logo{font-size:58px;color:#758974;display:flex;flex-direction:column;align-items:center}.lesson-cover .course-logo small{font-size:10px;margin-top:8px}.cover-expand{position:absolute;right:11px;bottom:10px;color:#92978b}.lesson-actions{display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid var(--line);padding:19px 0;gap:10px}.lesson-actions>div{display:flex;gap:17px}.lesson-actions button{display:flex;align-items:center;gap:6px;font-size:11px;color:#777b71}.lesson-actions .icon{width:16px;height:16px}.lesson-actions .saved{color:#486f52}.lesson-actions .teacher-access{color:#777b71}.lesson-section{scroll-margin-top:96px;margin-top:36px}.lesson-section h2{font-size:19px;font-weight:550;margin-bottom:18px;letter-spacing:-.3px}.section-index{font-size:11px;color:#b0b0a6;font-weight:400;margin-right:12px;vertical-align:middle;font-family:ui-monospace,SFMono-Regular,monospace}.lesson-section p,.lesson-section li{font-size:13px;line-height:1.95;color:#686a63}.lesson-section ul{padding-left:20px;margin:0}.lesson-section li{padding-left:4px;margin:7px 0}.lesson-note{background:#f7f8f4;border-left:2px solid #cbd6c6;padding:12px 16px;margin:20px 0;font-size:11px;line-height:1.9;color:#7a8072}.knowledge-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}.knowledge-unit{padding:15px;border:1px solid var(--line);border-radius:8px}.knowledge-unit b{font-size:12px;font-weight:550}.knowledge-unit p{font-size:11px;margin-top:8px;line-height:1.8}.materials{display:flex;gap:8px;flex-wrap:wrap}.materials span{font-size:11px;border:1px solid var(--line);border-radius:6px;padding:8px 10px;color:#77796f}.timeline{display:flex;flex-direction:column;gap:0}.step{display:grid;grid-template-columns:31px 1fr;position:relative;gap:14px;padding-bottom:25px}.step:before{content:"";position:absolute;left:14px;top:27px;bottom:0;width:1px;background:#e5e8de}.step:last-child:before{display:none}.step:last-child{padding-bottom:0}.step-number{width:29px;height:29px;display:grid;place-items:center;border:1px solid #e5e8df;border-radius:50%;font-size:10px;color:#8c9282;background:white;position:relative}.step h3{font-size:13px;font-weight:550;padding-top:4px}.step p{font-size:12px;margin-top:7px}.step-tip{margin-top:10px;font-size:11px;color:#84907b}.question-box{border:1px solid var(--line);border-radius:9px;padding:0 17px}.question-box p{font-size:12px;border-bottom:1px solid var(--line);padding:13px 0}.question-box p:last-child{border:0}.lesson-outline{position:sticky;top:110px;align-self:start}.outline-label{font-size:10px;color:#a0a096;margin:0 0 14px 14px}.outline-links{border-left:1px solid var(--line)}.outline-links a{display:block;font-size:11px;color:#97978c;padding:9px 13px;margin-left:-1px;border-left:2px solid transparent}.outline-links a.active{border-color:#678066;color:#4c634a;background:linear-gradient(90deg,#f3f6f1,transparent)}.outline-links a:hover{color:#3f533c}.outline-resource{border-top:1px solid var(--line);margin-top:30px;padding:19px 0 0 14px}.outline-resource p{font-size:10px;color:#9b9b90;margin-bottom:12px}.outline-resource a{display:flex;align-items:center;justify-content:space-between;font-size:11px;color:#717b69;gap:6px;line-height:1.8}.outline-resource .icon{width:13px;height:13px}.outline-resource small{font-size:9px;color:#aaa99e;display:block;margin-top:8px;line-height:1.8}.lesson-end{border-top:1px solid var(--line);margin-top:40px;padding-top:23px;display:flex;justify-content:space-between;gap:20px;color:#939789;font-size:10px;line-height:1.8}.lesson-end a{font-size:12px;color:#5f6957;white-space:nowrap}.path-visual{display:grid;grid-template-columns:repeat(6,1fr);gap:3px;width:70%;aspect-ratio:1}.path-visual i{border-radius:2px;background:#e9eee4}.path-visual i.on{background:#a9bca1}.path-visual i.wall{background:#d9ded4}
dialog{border:1px solid var(--line);border-radius:17px;background:white;color:var(--ink);padding:0;box-shadow:0 22px 100px #00000014}dialog::backdrop{background:#1b241a25;backdrop-filter:blur(4px)}#login-dialog{width:415px;max-width:calc(100% - 28px);padding:41px 35px 28px;text-align:center}.modal-close{position:absolute;right:12px;top:12px;font-size:14px;color:#8e9184}#login-dialog>.brand-symbol{width:30px;height:28px;margin-bottom:23px}#login-dialog h2{font-size:23px;font-weight:550}#login-dialog>p{font-size:12px;line-height:1.8;color:#9a9a90;margin-top:11px}.login-preview-note{font-size:10px;color:#798570;background:#f4f7f0;border-radius:6px;padding:9px;margin:24px 0 20px}#login-dialog label{display:block;text-align:left;font-size:11px;margin:15px 0 0;color:#757970}#login-dialog input{display:block;width:100%;padding:12px;margin-top:8px;border:1px solid var(--line);background:#fafaf8;border-radius:8px;font-size:12px}#login-dialog input::placeholder{color:#b0b2a7}.black-button{width:100%;padding:12px;border-radius:8px;background:#33372f;color:white;font-size:12px;margin-top:22px}.black-button:disabled{background:#aeb2a6}.text-button{padding:12px}#login-dialog>.text-button{margin:10px 0 2px}#login-dialog small{display:block;font-size:9px;color:#a2a598;line-height:1.8}.toast{position:fixed;bottom:28px;left:calc(50% + 118px);transform:translate(-50%,12px);background:#31362e;color:#f6f8f2;padding:11px 18px;border-radius:9px;font-size:12px;pointer-events:none;opacity:0;z-index:70;transition:.2s;max-width:90vw;text-align:center}.toast.visible{opacity:1;transform:translate(-50%,0)}#nav-dialog{margin:0;border-radius:0;border:0;width:270px;height:100dvh;max-height:none;background:var(--side);max-width:85vw}.mobile-sidebar{height:100%;display:flex;flex-direction:column}.nav-close{position:absolute;right:10px;top:23px;z-index:1;font-size:14px}
@media(min-width:1600px){.search-hero{padding-top:76px}.library-page{max-width:1200px}.search-box{margin-top:34px}.course-row{padding:24px 8px}}
@media(max-width:1180px){:root{--sidebar:212px}.library-page,.lesson-page{padding-left:32px;padding-right:32px}.lesson-layout{gap:28px;grid-template-columns:minmax(0,1fr) 140px}.course-aside{gap:6px}.row-stage{display:none}.category-tabs{gap:18px}.toast{left:calc(50% + 106px)}}
@media(max-width:960px){.lesson-layout{grid-template-columns:1fr}.lesson-outline{display:none}.grid-view{grid-template-columns:repeat(2,minmax(0,1fr))}.course-link{gap:15px}.course-row{gap:7px}.lesson-page{max-width:740px}.public-label{display:none}.search-hero h1{font-size:27px}.category-tabs{gap:17px}.topbar{padding:0 25px}.hero-caption{font-size:12px}}
@media(max-width:720px){:root{--sidebar:0px}.sidebar{display:none}.workspace{margin:0}.topbar{height:62px;padding:0 18px}.mobile-menu{display:flex;margin-left:-7px}.topbar-title{gap:8px}.topbar-title>a{font-size:14px}.workspace-chevron{display:none}.preview-label{font-size:8px;padding:3px 4px}.topbar-actions{gap:0}.login-button{font-size:11px;gap:7px;padding:0}.avatar{width:26px;height:26px}.library-page{padding:0 22px 35px}.search-hero{padding:38px 0 28px}.hero-brand{font-size:9px;margin-bottom:14px;letter-spacing:2px}.search-hero h1{font-size:26px;letter-spacing:-1px}.hero-caption{font-size:11px;line-height:1.8;margin-top:11px}.search-box{margin-top:26px;padding:16px 14px 10px;border-radius:19px}.search-input-row input{font-size:13px}.search-scope{font-size:9px}.suggestions{gap:6px;margin-top:13px}.suggestions button{padding:6px 9px;font-size:10px}.suggestions .icon{width:12px;height:12px}.catalogue-toolbar{margin-top:2px}.catalogue-heading{gap:8px}.catalogue-heading h2{font-size:14px}.result-count{font-size:10px}.catalogue-controls{gap:8px}.catalogue-controls select{font-size:10px;padding:6px;max-width:90px}.view-toggle button{padding:4px}.category-tabs{gap:21px;margin-top:21px}.category-tabs button{font-size:11px;padding-bottom:14px}.course-row{padding:18px 0;gap:4px}.course-link{gap:13px}.course-thumb{width:66px;height:61px;border-radius:8px}.course-copy h3{font-size:13px;gap:5px}.sample-tag{font-size:8px;padding:2px 3px}.course-knowledge{font-size:10px;margin-top:6px;max-width:100%}.course-meta{font-size:9px;margin-top:5px;gap:5px}.course-meta span+span:before{margin-right:5px}.save-button{padding:6px 0 6px 6px}.save-button .icon{width:15px}.course-aside{gap:0}.open-arrow{display:none}.grid-view{gap:12px}.grid-view .course-thumb{height:125px}.grid-view .course-copy{padding:12px}.grid-view .course-copy h3{font-size:12px}.grid-view .course-meta span:last-child{display:none}.grid-view .course-knowledge{font-size:10px}.grid-view .course-aside{top:5px;right:5px}.grid-view .save-button{padding:5px}.lesson-page{padding:18px 23px 50px}.lesson-layout{margin-top:28px;gap:0}.lesson-header h1{font-size:29px}.lesson-header .eyebrow{font-size:9px}.lesson-subtitle{font-size:12px}.lesson-pills{gap:6px}.lesson-pills span{font-size:9px;padding:5px 7px}.lesson-cover{height:213px;margin-top:22px}.lesson-actions{gap:5px}.lesson-actions>div{gap:12px}.lesson-actions button{font-size:10px}.lesson-section{margin-top:31px}.lesson-section h2{font-size:18px}.lesson-section p,.lesson-section li{font-size:12px}.knowledge-grid{grid-template-columns:1fr}.knowledge-unit{padding:14px}.knowledge-unit p{font-size:11px;margin-top:6px}.lesson-note{font-size:10px;padding:11px 13px}.lesson-end{flex-direction:column;gap:15px}.toast{left:50%;font-size:11px}.list-intro{padding:30px 0 25px}}
@media(prefers-reduced-motion:reduce){*,*:before,*:after{transition:none!important;scroll-behavior:auto!important}}
@media print{.sidebar,.topbar,.lesson-outline,.lesson-actions,.lesson-breadcrumb,.toast,.lesson-end{display:none}.workspace{margin:0}.lesson-page{padding:0;max-width:none}.lesson-layout{display:block}.lesson-section{break-inside:avoid}.lesson-cover{height:180px}}