@layer reset, base, components, responsive;
@layer reset {
*{box-sizing:border-box}body,h1,h2,h3,p,figure{margin:0}button,input,select{font:inherit}button,a,input{touch-action:manipulation}button{cursor:pointer}a{color:inherit;text-decoration:none}button{color:inherit}img,canvas{display:block;max-width:100%}html{scroll-behavior:smooth}button:disabled{cursor:wait;opacity:.55}
}
@layer base {
:root{--paper:#f3f5f6;--white:#fff;--ink:#252b32;--muted:#687581;--blue:#294b72;--line:#d9dfe3;--lavender:#b6a8cb;--pink:#be795d;--display:'Songti SC','Noto Serif CJK SC','STSong',serif;--mono:'SFMono-Regular',Consolas,monospace}
body{background:var(--paper);color:var(--ink);font-family:'PingFang SC','Microsoft YaHei',system-ui,sans-serif;font-size:15px;line-height:1.7;-webkit-font-smoothing:antialiased}button{border:0;background:none}::selection{background:#d2dbe9}a:hover{color:var(--blue)}:focus-visible{outline:2px solid var(--blue);outline-offset:5px}h1,h2,h3{font-weight:500;line-height:1.3}main{min-height:65vh}small{font-size:12px}.mono,.eyebrow{font-family:var(--mono)}.eyebrow{font-size:11px;letter-spacing:.14em;color:var(--muted);text-transform:uppercase}.muted{color:var(--muted)}.wrap{width:min(1280px,calc(100% - 96px));margin-inline:auto}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}.skip-link{position:fixed;top:-80px;left:20px;background:white;padding:10px;z-index:100}.skip-link:focus{top:10px}.loading{padding:10vh;text-align:center}.empty{padding:60px 20px;text-align:center;color:var(--muted)}
}
@layer components {
.hero-canvas{width:100%;height:100%}
.lesson-intro{max-width:760px;font-size:14px;line-height:1.95;color:#525e69;margin:0 0 38px}
.site-header{height:100px;width:min(1380px,calc(100% - 80px));margin:auto;display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid var(--line);gap:24px}.brand{display:flex;align-items:center;gap:13px;font-size:17px;letter-spacing:.06em;font-weight:550}.brand small{display:block;font:9px/1.8 var(--mono);letter-spacing:.18em;color:var(--muted)}.site-header nav{display:flex;gap:38px;font-size:13px}.site-header nav a:last-child{margin-left:20px}.site-footer{display:flex;align-items:center;justify-content:space-between;gap:20px;width:min(1380px,calc(100% - 80px));border-top:1px solid var(--line);margin:80px auto 0;padding:28px 0;font-size:12px;color:var(--muted)}.site-footer>a:first-child{font-family:var(--display);font-size:18px;color:var(--ink)}
.hero{display:grid;grid-template-columns:.85fr 1.15fr;align-items:center;gap:64px;padding:56px 0 64px}.hero-copy{padding-bottom:10px}.hero h1{font-family:var(--display);font-size:clamp(40px,4.5vw,64px);letter-spacing:.015em;line-height:1.35;margin:27px 0 25px}.hero h1 em{font-style:normal;color:var(--blue)}.hero-copy>p:not(.eyebrow){max-width:345px;color:var(--muted);line-height:1.95;font-size:14px}.hero-actions{display:flex;gap:23px;align-items:center;margin-top:32px}.button{display:inline-flex;gap:20px;align-items:center;justify-content:center;padding:12px 22px;border-radius:4px;background:var(--blue);color:white;font-size:13px;border:1px solid var(--blue);white-space:nowrap}.button:hover{background:#203d5f;color:white}.button.secondary{background:transparent;color:var(--blue);border-color:var(--line)}.text-link{font-size:13px;border-bottom:1px solid var(--line);padding:7px 0}.hero-work{position:relative;background:#e9edf1;border:1px solid #e0e5e9;padding:16px;border-radius:3px}.hero-work .artwork{height:400px;background:#f9fafb;border:1px solid #e2e5e8}.hero-work figcaption{display:flex;align-items:center;justify-content:space-between;font:10px/1.5 var(--mono);color:var(--muted);margin-top:13px;gap:10px}.hero-work .work-title{color:var(--ink);font-family:inherit}.small-button{border:1px solid var(--line);border-radius:3px;padding:5px 10px;font-size:11px;background:#ffffffaa}.hero-note{font-size:10px!important;letter-spacing:.04em;margin-top:24px;color:#81909e!important}.section-head{display:flex;align-items:end;justify-content:space-between;gap:20px;margin:0 0 28px}.section-head h2{font-family:var(--display);font-size:30px;margin-top:7px}.section-head p{font-size:12px;color:var(--muted)}.catalog{padding-top:38px;border-top:1px solid var(--line);scroll-margin-top:20px}.filters{display:flex;align-items:center;justify-content:space-between;gap:20px;margin:25px 0 28px}.filter-tabs{display:flex;gap:5px;flex-wrap:wrap}.filter-tabs button{padding:8px 15px;font-size:12px;border:1px solid transparent;border-radius:30px;color:var(--muted)}.filter-tabs button[aria-pressed=true]{color:var(--blue);border-color:#b6c4d1;background:#e8eef3}.search{width:240px;border:0;border-bottom:1px solid #bdc7d0;background:transparent;padding:8px 0 8px 5px;outline-offset:2px;font-size:12px;border-radius:0}.course-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:38px 26px}.course-card{min-width:0}.course-art{background:#e9edf1;border-radius:3px;position:relative;overflow:hidden;height:226px;border:1px solid #e2e7e9;transition:transform .3s ease}.course-art canvas{height:100%;width:100%}.course-card:nth-child(3n+2) .course-art{background:#edeaf0}.course-card:nth-child(3n+3) .course-art{background:#e8eeed}.course-card:hover .course-art{transform:translateY(-3px)}.card-index{position:absolute;top:14px;left:16px;font:10px var(--mono);color:#73808b}.card-arrow{position:absolute;right:12px;bottom:10px;font-size:20px;color:var(--blue);background:#ffffffb8;border-radius:50%;width:30px;height:30px;text-align:center;line-height:28px}.course-meta{display:flex;align-items:center;justify-content:space-between;margin:16px 0 7px;color:var(--muted);font-size:10px}.course-card h3{font-family:var(--display);font-size:23px;display:flex;align-items:baseline;gap:10px}.course-card h3 small{font:10px var(--mono);color:var(--muted);letter-spacing:.01em}.course-card p{font-size:12px;color:var(--muted);line-height:1.8;margin-top:8px}.tag{font-size:10px;border:1px solid #d4dfda;color:#4c7664;border-radius:3px;padding:1px 6px}.section-subhead{margin:64px 0 23px;display:flex;justify-content:space-between;align-items:center}.section-subhead h2{font-family:var(--display);font-size:25px}.section-subhead p{font-size:12px;color:var(--muted)}.album-grid{display:grid;grid-template-columns:1fr 1fr;gap:24px}.album-card{padding:28px 30px;border:1px solid var(--line);border-radius:3px;background:#f9fafb;display:grid;grid-template-columns:1fr auto;gap:8px 20px;align-items:start}.album-card h3{font-family:var(--display);font-size:27px;margin:9px 0}.album-card p{font-size:12px;color:var(--muted);max-width:390px}.album-count{font:11px var(--mono);color:var(--muted)}.album-card>a{margin-top:17px;justify-self:start}.album-card .album-symbol{font:60px var(--display);color:#9babc0;line-height:1.2;grid-column:2;grid-row:1/5}.test-note{margin-top:27px;font-size:12px;color:var(--muted);display:flex;gap:15px;align-items:center}.test-note a{text-decoration:underline;text-underline-offset:4px}
.page-heading{padding:58px 0 40px}.page-heading h1{font:46px/1.35 var(--display);margin:14px 0 20px}.page-heading>p:last-child{color:var(--muted);font-size:14px;max-width:650px}.breadcrumbs{display:flex;align-items:center;gap:10px;font-size:12px;color:var(--muted);padding-top:28px;flex-wrap:wrap}.curriculum{display:grid;grid-template-columns:230px 1fr;gap:64px}.curriculum-aside{align-self:start;position:sticky;top:30px}.curriculum-aside>p{font-size:12px;color:var(--muted);line-height:1.9;margin:14px 0 22px}.curriculum-row{display:grid;grid-template-columns:35px 1fr auto;gap:18px;padding:22px 8px;border-top:1px solid var(--line);align-items:center}.curriculum-row .row-index{font:11px var(--mono);color:var(--muted)}.curriculum-row h3{font-size:16px;margin-bottom:4px}.curriculum-row p{font-size:11px;color:var(--muted)}.curriculum-row .row-state{font-size:11px;color:var(--muted);white-space:nowrap}.curriculum-row.ready .row-state{color:var(--blue)}.curriculum-row:hover{background:#eaf0f3}.lesson-top{padding:30px 0 35px}.lesson-top .eyebrow{margin:25px 0 13px}.lesson-top h1{font:48px/1.3 var(--display);margin-bottom:17px}.lesson-top p{color:var(--muted);max-width:690px;font-size:14px;line-height:1.95}.lesson-meta{display:flex;gap:17px;margin-top:20px;font-size:11px;color:var(--muted)}.lesson-grid{display:grid;grid-template-columns:1fr 1.15fr;gap:58px;align-items:start}.lesson-copy{max-width:660px}.prose-section{margin-bottom:35px;scroll-margin-top:25px}.prose-section h2{font:25px/1.5 var(--display);margin-bottom:16px}.prose-section p{font-size:14px;line-height:2;color:#525e69;margin-bottom:14px}.prose-section pre{background:#e7ecf0;border-left:2px solid #b4c5d5;padding:20px;overflow:auto;font:12px/1.9 var(--mono);margin:20px 0;color:#344e65;border-radius:0 3px 3px 0}.experiment{min-width:0;border:1px solid var(--line);background:#edf0f3;border-radius:4px;overflow:hidden}.lesson-grid>.experiment{position:sticky;top:24px}.experiment-header{display:flex;justify-content:space-between;gap:12px;padding:13px 18px;border-bottom:1px solid var(--line);font-size:11px}.experiment-header span:last-child{font:10px/1.8 var(--mono);color:var(--muted)}.experiment-canvas{width:100%;height:400px}.experiment-tools{display:flex;gap:5px;align-items:center;padding:10px 13px;border-top:1px solid var(--line);flex-wrap:wrap;background:#f7f9fa}.experiment-tools button{padding:6px 9px;font-size:11px;border-radius:3px}.experiment-tools button:hover{background:#e2e9ef}.experiment-tools button:last-child{margin-left:auto}.controls{padding:16px 20px;background:#f7f9fa;display:grid;grid-template-columns:1fr 1fr;gap:17px 25px;border-top:1px solid var(--line)}.control label{display:flex;justify-content:space-between;font-size:11px;margin-bottom:7px;gap:15px}.control output{font:11px var(--mono);color:var(--blue)}.control input{display:block;width:100%;height:15px;accent-color:var(--blue);cursor:pointer}.exercise{border-top:1px solid var(--line);padding-top:26px;margin-top:35px}.exercise .eyebrow{color:var(--blue)}.exercise p{font-size:14px;color:var(--muted);line-height:1.9;margin:12px 0 22px}.lesson-bottom{margin-top:40px;padding-top:25px;border-top:1px solid var(--line);display:flex;justify-content:space-between;align-items:center;gap:20px;font-size:12px}.source-note{font-size:11px;color:var(--muted);margin-top:24px}.source-note a{text-decoration:underline;text-underline-offset:3px}.immersive-stage .experiment-canvas{height:530px}.immersive-stage .controls{grid-template-columns:repeat(4,1fr)}.immersive-text{display:grid;grid-template-columns:210px 1fr;gap:80px;margin:50px auto 0;max-width:1020px}.lesson-toc{position:sticky;top:30px;align-self:start;font-size:12px;color:var(--muted)}.lesson-toc a{display:block;margin:13px 0}.notebook{max-width:960px;margin:auto}.notebook-intro{max-width:620px;margin:0 auto 30px}.notebook .experiment{margin:35px 0}.notebook .lesson-copy{margin:auto}.notebook .experiment-canvas{height:430px}.outline-note{max-width:780px;padding:35px;border:1px solid var(--line);background:#fafbfc}.outline-note h2{font:25px var(--display);margin-bottom:18px}.outline-note p{font-size:14px;color:var(--muted);margin-bottom:25px}.progress-badge{font-size:11px;color:#4c7664}.payment-panel{max-width:680px;margin:0 auto;background:#fafbfc;border:1px solid var(--line);padding:38px}.payment-line{display:flex;justify-content:space-between;padding:23px 0;border-top:1px solid var(--line);gap:20px}.payment-panel p{font-size:13px;color:var(--muted);margin-bottom:20px}.payment-panel label{display:block;font-size:12px;margin-bottom:8px}.payment-panel input{width:100%;border:1px solid var(--line);background:white;padding:12px;margin-bottom:20px;border-radius:3px}.payment-panel .button{width:100%}.status-message{font-size:13px;line-height:1.9;margin:20px 0;color:var(--blue)}.status-message:empty{display:none}.saved-empty{padding:50px;border:1px solid var(--line);max-width:650px}.saved-empty h2{font:26px var(--display);margin-bottom:14px}.saved-empty p{color:var(--muted);margin-bottom:26px}.gallery-grid{display:grid;grid-template-columns:1fr 1fr;gap:24px}.gallery-item{position:relative;border:1px solid var(--line);background:#e9edf1}.gallery-item canvas{width:100%;height:400px}.gallery-item figcaption{padding:15px 20px;background:var(--paper);display:flex;justify-content:space-between;border-top:1px solid var(--line);font-size:12px}.notice{background:#e7edf2;padding:14px 18px;font-size:12px;color:var(--blue);margin-top:20px}.resume{display:none;margin-top:20px;font-size:12px;color:var(--blue)}.resume.visible{display:block}
}
@layer responsive {
@media(min-width:1550px){.hero-work .artwork{height:450px}.hero{gap:90px}}
@media(max-width:1050px){.wrap{width:calc(100% - 64px)}.hero{gap:35px}.hero h1{font-size:44px}.hero-work .artwork{height:350px}.course-art{height:200px}.course-grid{gap:30px 20px}.lesson-grid{gap:30px}.lesson-top h1{font-size:40px}.experiment-canvas{height:350px}.curriculum{gap:35px}.immersive-text{gap:40px}.course-card h3 small{display:none}}
@media(max-width:760px){.site-header{height:82px;width:calc(100% - 40px);gap:15px}.brand{font-size:14px;gap:8px}.brand img{width:28px;height:28px}.brand small{font-size:7px}.site-header nav{gap:17px;font-size:11px}.site-header nav a:last-child{margin-left:0}.wrap{width:calc(100% - 40px)}.hero{grid-template-columns:1fr;padding:35px 0 40px;gap:30px}.hero-copy{padding:0}.hero h1{font-size:47px;margin:17px 0}.hero h1 br{display:none}.hero-copy>p:not(.eyebrow){max-width:100%;font-size:13px}.hero-actions{margin-top:24px}.hero-note{display:none}.hero-work .artwork{height:360px}.hero-work{padding:10px}.hero-work figcaption{margin:10px 3px 2px;font-size:9px}.section-head h2{font-size:27px}.section-head>p{display:none}.catalog{padding-top:30px}.filters{align-items:start;flex-direction:column;gap:17px}.search{width:100%}.filter-tabs{gap:0}.filter-tabs button{padding:7px 12px;font-size:11px}.course-grid{grid-template-columns:1fr 1fr;gap:27px 16px}.course-art{height:210px}.course-card h3{font-size:22px}.course-card p{font-size:11px}.course-meta{font-size:9px;margin-top:12px}.course-meta .duration{display:none}.album-grid{grid-template-columns:1fr}.album-card{padding:25px}.section-subhead{margin-top:45px}.section-subhead p{display:none}.test-note{align-items:start;flex-wrap:wrap;gap:5px}.site-footer{width:calc(100% - 40px);margin-top:55px;padding:23px 0;flex-wrap:wrap;font-size:10px}.site-footer>a:first-child{font-size:16px}.page-heading{padding:35px 0 30px}.page-heading h1{font-size:35px}.curriculum{grid-template-columns:1fr;gap:15px}.curriculum-aside{position:static}.curriculum-aside>p{margin-top:7px}.curriculum-row{gap:10px;grid-template-columns:26px 1fr auto;padding:18px 0}.curriculum-row h3{font-size:14px}.curriculum-row p{font-size:10px}.lesson-top h1{font-size:36px}.lesson-top{padding-top:15px}.lesson-grid{display:flex;flex-direction:column;gap:35px}.lesson-grid>.experiment{position:static;width:100%;order:-1}.lesson-copy{max-width:none}.experiment-canvas{height:360px}.lesson-top p{font-size:13px}.immersive-stage .experiment-canvas{height:420px}.immersive-stage .controls{grid-template-columns:1fr 1fr}.immersive-text{grid-template-columns:1fr;gap:25px;margin-top:30px}.lesson-toc{display:flex;position:static;gap:10px 20px;flex-wrap:wrap;border-bottom:1px solid var(--line);padding-bottom:15px}.lesson-toc .eyebrow{width:100%}.lesson-toc a{margin:0}.prose-section p{font-size:13px}.notebook .experiment-canvas{height:340px}.lesson-bottom{align-items:start}.outline-note,.payment-panel,.saved-empty{padding:25px}.gallery-grid{grid-template-columns:1fr}.gallery-item canvas{height:380px}}
@media(max-width:420px){.site-header nav{gap:12px}.site-header nav a:nth-child(2){display:none}.hero h1{font-size:40px}.hero-work .artwork{height:295px}.course-grid{gap:25px 13px}.course-art{height:170px}.course-card h3{font-size:20px}.course-card p{line-height:1.7}.course-meta .tag{font-size:8px;padding:0 4px}.hero-actions{gap:18px}.button{padding:11px 17px}.hero-work figcaption .work-title{max-width:150px}.experiment-canvas{height:290px}.controls{gap:14px;padding:15px}.lesson-top h1{font-size:32px}.lesson-meta{gap:12px;font-size:10px}.site-footer span{display:none}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*::before,*::after{transition:none!important;animation:none!important}}
}

.lesson-preview{display:block;width:100%;height:100%;object-fit:cover}