:root{font-family:Inter,"Segoe UI","Microsoft YaHei",sans-serif;color:#1b293b;background:#f5f7fa;font-synthesis:none;--blue:#245ce4;--muted:#737f91;--line:#e5eaf1;--navy:#152c49}*{box-sizing:border-box}body{margin:0}button,input,select,textarea{font:inherit}button,a,input,textarea,select{outline-offset:4px}button,a{touch-action:manipulation}button{cursor:pointer}a{color:var(--blue);text-decoration:none}a:hover{text-decoration:underline}button:disabled{opacity:.55;cursor:wait}button{border:0;background:none;color:inherit}h1,h2,h3,p{margin:0}header{height:80px;background:white;border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;padding:0 max(32px,calc((100vw - 1160px)/2));gap:20px}.brand{display:flex;align-items:center;gap:12px;font-weight:750;font-size:19px;white-space:nowrap}.brand-mark{display:grid;place-items:center;width:36px;height:36px;background:var(--blue);color:white;border-radius:10px}.brand-mark svg{width:23px}.nav{display:flex;align-items:center;gap:22px;font-size:13px}.nav a,.nav button{color:#657286}.badge{display:inline-flex;align-items:center;gap:7px;border-radius:30px;font-size:11px;padding:6px 10px;background:#eaf0ff;color:#2c5fc6;letter-spacing:.3px}.dot{width:6px;height:6px;background:#5481ef;border-radius:50%}.wrap{max-width:1160px;margin:auto;padding:0 28px}.hero{position:relative;padding:49px 0 36px;display:flex;justify-content:space-between;gap:32px}.hero h1{font-size:36px;letter-spacing:-1.3px;font-weight:750;margin:14px 0 12px;line-height:1.4}.hero p{color:var(--muted);font-size:14px;line-height:1.9}.hero-art{width:190px;display:flex;align-items:center;justify-content:center;position:relative;color:#7693c6}.hero-art svg{width:142px;height:142px}.search-box{display:flex;align-items:center;background:white;border:1px solid #d7dfeb;box-shadow:0 5px 20px #223b6510;border-radius:14px;padding:8px 8px 8px 20px;gap:12px}.search-box:focus-within{border-color:#7397ef;box-shadow:0 0 0 3px #245ce412}.search-box svg{width:21px;stroke:#7c8999;flex-shrink:0}.search-box input{width:100%;border:0;outline:none;background:none;height:44px;font-size:15px;min-width:0}.primary{background:var(--blue);color:white;border-radius:8px;padding:12px 24px;font-size:14px;white-space:nowrap;font-weight:600}.primary:hover{background:#184ac2}.secondary{border:1px solid #dce3ee;border-radius:8px;padding:10px 16px;background:white;font-size:13px}.secondary:hover{background:#f1f5ff}.suggestions{display:flex;gap:12px;align-items:center;flex-wrap:wrap;font-size:12px;color:#8b95a4;margin-top:13px}.suggestions button{color:#657389;padding:4px 0}.suggestions button:hover{color:var(--blue)}.layout{display:grid;grid-template-columns:minmax(0,1fr) 270px;gap:27px;margin:34px 0 50px}.section-title{display:flex;justify-content:space-between;align-items:center;margin:0 0 19px}.section-title h2{font-size:17px}.section-title span{font-size:12px;color:var(--muted)}.tabs{display:flex;gap:5px;flex-wrap:wrap;margin-bottom:20px}.tab{padding:9px 13px;border-radius:8px;font-size:12px;color:#667389;transition:.15s}.tab:hover{background:#eaf0fb}.tab.active{background:#e7eeff;color:var(--blue);font-weight:600}.cards{display:grid;grid-template-columns:1fr 1fr;gap:15px}.card{padding:21px;background:white;border:1px solid var(--line);border-radius:12px;display:flex;flex-direction:column;min-height:224px;transition:transform .15s,border-color .15s}.card:hover{border-color:#b9cbf1;transform:translateY(-2px)}.card-top{display:flex;justify-content:space-between;align-items:center;margin-bottom:14px}.lesson-icon{width:34px;height:34px;border-radius:9px;background:#edf2ff;display:grid;place-items:center;color:#4e77cd}.lesson-icon svg{width:18px;stroke:currentColor}.platform{font-size:10px;color:#8892a2;background:#f5f7fa;border:1px solid #edf0f5;border-radius:5px;padding:4px 7px;max-width:65%;text-align:right}.card h3{font-size:15px;line-height:1.6;margin-bottom:8px}.card p{font-size:12px;color:var(--muted);line-height:1.85;margin-bottom:16px}.card-bottom{margin-top:auto;display:flex;justify-content:space-between;align-items:center;gap:5px;border-top:1px solid #f0f2f6;padding-top:12px;font-size:11px;color:#8c96a5}.card-bottom a{font-size:12px;font-weight:600}.side-card{background:white;border:1px solid var(--line);border-radius:12px;padding:23px;margin-bottom:17px}.side-card h2{font-size:15px;margin:10px 0}.side-card p{font-size:12px;color:#778394;line-height:1.95;margin-bottom:17px}.support-icon{background:#eaf1ff;color:#4872cb;border-radius:12px;width:42px;height:42px;display:grid;place-items:center;font-size:22px}.full{width:100%}.side-card.dark{background:var(--navy);color:white;border:0}.side-card.dark p{color:#c0cce0;margin:12px 0 0}.side-card small{font-size:10px;color:#91a6c4;letter-spacing:1px}.service-note{font-size:11px;line-height:1.9;color:#8993a2;padding:4px 4px 0}.service-note strong{color:#65728a}.footer{border-top:1px solid var(--line);display:flex;justify-content:space-between;font-size:11px;color:#929baa;padding:24px 0;gap:15px}.empty{padding:55px 20px;text-align:center;background:white;border:1px dashed #ced8e8;border-radius:12px;grid-column:1/-1}.empty h3{font-size:16px;margin-bottom:10px}.empty p{font-size:13px;color:var(--muted);line-height:2;margin-bottom:18px}.auth-screen{min-height:100vh;display:grid;grid-template-columns:1.05fr 1fr}.auth-intro{background:var(--navy);color:white;padding:60px;display:flex;flex-direction:column;justify-content:space-between}.auth-intro h1{font-size:44px;line-height:1.5;letter-spacing:-1px;margin-bottom:20px}.auth-intro p{color:#b6c6dd;font-size:14px;line-height:2}.auth-intro .brand-mark{background:#456ee0}.auth-foot{font-size:12px;color:#9aaec9}.auth-main{display:grid;place-items:center;padding:40px}.auth-form{width:100%;max-width:360px}.eyebrow{font-size:11px;letter-spacing:2px;color:var(--blue);margin-bottom:12px}.auth-form h2{font-size:27px;margin-bottom:12px}.muted{color:var(--muted);font-size:13px;line-height:1.9}.form{display:grid;gap:17px;margin-top:26px}.field{display:grid;gap:8px;font-size:12px;color:#5b687a}.field input,.field textarea,.field select{width:100%;padding:11px 12px;border:1px solid #d8e0eb;border-radius:8px;background:#fff;color:#25344b;line-height:1.6}.field textarea{resize:vertical;min-height:85px}.field input:focus,.field textarea:focus,.field select:focus{border-color:#6e93e8}.error{color:#c23939;font-size:12px;line-height:1.7;min-height:0}.auth-switch{display:flex;justify-content:space-between;margin-top:25px;font-size:12px}.loading{padding:20vh 20px;text-align:center;color:var(--muted)}#toast{position:fixed;bottom:30px;left:50%;transform:translateX(-50%);background:#20344e;color:white;border-radius:10px;padding:12px 22px;font-size:13px;box-shadow:0 5px 25px #0002;z-index:20;display:none;max-width:90vw}#toast.show{display:block}dialog{border:0;border-radius:16px;padding:28px;width:min(480px,calc(100% - 32px));box-shadow:0 20px 100px #0003;color:#24344a}dialog::backdrop{background:#13243b77}dialog h2{font-size:21px;margin-bottom:14px}dialog p{font-size:13px;line-height:1.9;color:#6e7b8d;white-space:pre-line}.dialog-actions{display:flex;gap:10px;margin-top:20px;justify-content:flex-end}.contact-value{display:block;padding:14px;margin:15px 0;background:#f0f4fb;border-radius:8px;overflow-wrap:anywhere}.template{white-space:pre-wrap;font-size:12px;line-height:1.8;background:#f7f8fb;padding:15px;border-radius:8px}.admin-wrap{max-width:1200px;margin:auto;padding:30px 28px}.admin-head{display:flex;align-items:center;justify-content:space-between;gap:18px;margin-bottom:24px}.admin-head h1{font-size:25px}.admin-tabs{display:flex;gap:8px;border-bottom:1px solid var(--line);padding-bottom:15px;margin-bottom:24px}.admin-tabs button{padding:9px 15px;border-radius:8px;font-size:13px}.admin-tabs .active{color:var(--blue);background:#e9efff}.panel{background:white;border:1px solid var(--line);padding:24px;border-radius:12px}.admin-grid{display:grid;grid-template-columns:1fr 380px;gap:22px;align-items:start}.admin-list{display:grid;gap:10px}.admin-item{padding:16px;border:1px solid var(--line);border-radius:10px;display:flex;justify-content:space-between;align-items:center;gap:14px}.admin-item h3{font-size:13px;line-height:1.7}.admin-item p{font-size:11px;color:var(--muted);margin-top:5px}.admin-item button{font-size:12px;color:var(--blue);padding:7px}.admin-item.selected{border-color:#7f9fe8;background:#f6f8ff}.admin-tools{display:flex;gap:12px;align-items:center;margin-bottom:18px}.admin-tools input{min-width:0;flex:1;padding:11px;border:1px solid #d8e0eb;border-radius:8px}.panel h2{font-size:17px}.panel .form{margin-top:18px}.row{display:grid;grid-template-columns:1fr 1fr;gap:12px}.check{display:flex;align-items:center;gap:8px;font-size:13px}.check input{width:16px;height:16px}.danger{color:#b74747}.setting-panel{max-width:720px}.hint{font-size:11px;color:#8390a1;line-height:1.8}.category-row{display:flex;gap:10px;margin:12px 0;align-items:center}.category-row input{flex:1;min-width:0;padding:10px;border:1px solid #d8e0eb;border-radius:8px}.link-button{font-size:12px;color:var(--blue)}.admin-notice{background:#edf3ff;color:#516b98;font-size:12px;line-height:1.9;padding:12px 16px;border-radius:9px;margin-bottom:20px}.mobile-only{display:none}
@media(min-width:1400px){.hero{padding-top:58px}.layout{margin-top:39px}.card{min-height:232px}}
@media(max-width:900px){.layout{grid-template-columns:minmax(0,1fr) 230px;gap:18px}.wrap{padding:0 22px}.cards{grid-template-columns:1fr}.hero-art{width:145px}.admin-grid{grid-template-columns:1fr 340px}.auth-intro{padding:38px}.auth-intro h1{font-size:34px}}
@media(max-width:650px){header{height:66px;padding:0 19px}.brand{font-size:16px;gap:9px}.brand-mark{width:31px;height:31px}.nav{gap:12px;font-size:12px}.nav .badge{display:none}.wrap{padding:0 18px}.hero{padding:30px 0 25px}.hero h1{font-size:28px;letter-spacing:-.8px}.hero p{font-size:12px}.hero-art{display:none}.search-box{padding-left:13px;border-radius:11px;gap:8px}.search-box input{font-size:13px}.primary{padding:12px 17px}.suggestions{gap:10px;font-size:11px}.layout{display:flex;flex-direction:column;margin-top:27px;gap:28px}.cards{grid-template-columns:1fr}.card{min-height:195px;padding:19px}.tabs{gap:2px}.tab{padding:8px 10px;font-size:11px}.side-card{padding:20px}.footer{flex-direction:column;gap:9px}.auth-screen{display:block}.auth-intro{min-height:210px;padding:26px}.auth-intro>div:nth-child(2){margin-top:27px}.auth-intro h1{font-size:25px;margin-bottom:7px}.auth-intro p{font-size:12px}.auth-foot{display:none}.auth-main{padding:32px 24px}.auth-form h2{font-size:23px}.admin-wrap{padding:25px 17px}.admin-grid{grid-template-columns:1fr}.admin-head{align-items:start}.admin-head h1{font-size:22px}.admin-tabs{flex-wrap:wrap;gap:3px}.admin-tabs button{padding:8px 12px}.panel{padding:18px}.admin-tools .primary{padding:12px}.admin-item{padding:12px}.mobile-only{display:block}.hero .badge{font-size:10px}.row{grid-template-columns:1fr 1fr}}

.brand-image{object-fit:contain;background:transparent;border-radius:0;flex-shrink:0;width:44px;height:44px}.brand{white-space:normal;line-height:1.4}header .brand{min-width:0}.nav{flex-shrink:0}@media(max-width:650px){.brand-image{width:36px;height:36px}.brand{font-size:14px}header{gap:10px}}

/* Tutorial results: clear titles and a prominent viewing action. */
.hero{padding:36px 0 28px}.hero h1{font-size:34px}.layout{gap:24px;margin-top:30px;grid-template-columns:minmax(0,1fr) 260px}.section-title{margin-bottom:16px}.section-title h2{font-size:20px}.tabs{gap:6px;margin-bottom:22px}.tab{font-size:13px;padding:10px 14px}.cards{gap:20px}.card{padding:24px;min-height:270px;border-radius:16px;box-shadow:0 4px 18px #243b5710}.card:hover{border-color:#a9c0f3;box-shadow:0 8px 24px #243b5718}.card-top{margin-bottom:14px}.card h3{font-size:18px;line-height:1.55;margin-bottom:10px}.card p{font-size:14px;line-height:1.85;margin-bottom:20px}.platform{font-size:11px}.card-bottom{flex-direction:column;align-items:stretch;gap:12px;padding-top:16px}.card-bottom>span{font-size:12px;color:#748297}.card-bottom a{display:flex;align-items:center;justify-content:center;gap:12px;width:100%;min-height:48px;padding:12px 18px;background:var(--blue);color:white;border-radius:10px;font-size:16px;font-weight:700;text-decoration:none;transition:background .15s,box-shadow .15s}.card-bottom a:hover{background:#184ac2;box-shadow:0 4px 12px #245ce430}.card-bottom a:focus-visible{outline:3px solid #98b4ff;outline-offset:3px}.tutorial-play{font-size:13px}.side-card{border-radius:16px}.side-card h2{font-size:16px}.side-card p{font-size:13px;line-height:1.9}.footer{margin-top:30px}
@media(min-width:1400px){.hero{padding-top:42px}.layout{margin-top:32px}.card{min-height:270px}}
@media(max-width:1000px){.layout{grid-template-columns:minmax(0,1fr) 230px;gap:20px}.cards{grid-template-columns:1fr}.card{min-height:240px}}
@media(max-width:650px){.hero{padding:28px 0 24px}.hero h1{font-size:28px}.layout{display:flex;margin-top:26px}.cards{gap:16px}.card{padding:21px;min-height:240px}.card h3{font-size:17px}.card p{font-size:13px}.card-bottom a{min-height:48px;font-size:16px}.section-title h2{font-size:18px}.tab{font-size:12px;padding:9px 11px}.tabs{gap:4px}.side-card{padding:21px}}