@import"https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=Sora:wght@500;600;700;800&display=swap";:root{--bg: #05070d;--bg-2: #080b14;--surface: #0d111c;--surface-2: #131826;--surface-3: #1a2133;--border: rgba(148, 170, 220, .1);--border-2: rgba(148, 170, 220, .18);--text: #f1f4fb;--text-2: #c3cad9;--muted: #8690a8;--accent: #1f6bff;--accent-2: #2fc4ff;--accent-soft: rgba(31, 107, 255, .14);--glow: 0 0 0 1px rgba(47, 196, 255, .25), 0 10px 40px -10px rgba(31, 107, 255, .65);--success: #2ee59d;--success-soft: rgba(46, 229, 157, .12);--danger: #ff6b7a;--radius: 16px;--radius-sm: 11px;--shadow: 0 30px 80px -30px rgba(0, 0, 0, .85);--topbar: 68px;--display: Sora, Inter, system-ui, sans-serif;color-scheme:dark}*{box-sizing:border-box}html,body{margin:0}body{background:var(--bg);color:var(--text);font:15px/1.6 Inter,system-ui,-apple-system,Segoe UI,sans-serif;-webkit-font-smoothing:antialiased;min-height:100vh}body:before{content:"";position:fixed;inset:0 0 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var(--accent-2);outline-offset:2px;border-radius:6px}.muted{color:var(--muted)}.text{color:var(--text)}.small{font-size:.85rem}.center{text-align:center}.clamp-1,.clamp-2{display:-webkit-box;-webkit-box-orient:vertical;overflow:hidden}.clamp-1{-webkit-line-clamp:1}.clamp-2{-webkit-line-clamp:2}.eyebrow{text-transform:uppercase;letter-spacing:.16em;font-size:.7rem;font-weight:700;color:var(--accent-2);margin-bottom:.7em}.gradient-text{background:linear-gradient(100deg,#fff 0%,var(--accent-2) 45%,var(--accent) 100%);-webkit-background-clip:text;background-clip:text;color:transparent}.container{width:100%;max-width:1200px;margin:0 auto;padding:0 28px}.page{padding-top:40px;padding-bottom:96px}.narrow{max-width:680px}.back{display:inline-flex;align-items:center;gap:6px;color:var(--muted);font-size:.88rem;font-weight:500;margin-bottom:22px;transition:color .15s}.back:hover{color:var(--text)}.card{background:linear-gradient(180deg,rgba(255,255,255,.025),transparent 40%),var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:26px}.section-head{display:flex;align-items:baseline;justify-content:space-between;gap:16px;margin:52px 0 18px}.section-title{font-size:1.35rem;margin:0}.lead-sm{max-width:520px;margin:0}.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;height:44px;padding:0 20px;border-radius:var(--radius-sm);border:1px solid transparent;font-weight:600;font-size:.93rem;cursor:pointer;white-space:nowrap;transition:transform .15s,background .15s,border-color .15s,box-shadow .2s,color .15s}.btn:disabled{opacity:.5;cursor:not-allowed}.btn:active:not(:disabled){transform:translateY(1px)}.btn-primary{background:linear-gradient(180deg,#3d82ff,var(--accent));color:#fff;box-shadow:inset 0 1px #ffffff40,var(--glow)}.btn-primary:hover:not(:disabled){box-shadow:inset 0 1px #ffffff4d,0 0 0 1px #2fc4ff73,0 14px 46px -10px #1f6bffe6}.btn-ghost{background:transparent;color:var(--text-2)}.btn-ghost:hover:not(:disabled){color:var(--text);background:var(--surface-2)}.btn-outline{background:var(--surface);border-color:var(--border-2)}.btn-outline:hover{border-color:var(--accent-2)}.btn-success{background:var(--success-soft);color:var(--success);border-color:#2ee59d4d}.btn-block{width:100%}.btn-lg{height:52px;font-size:1rem}.btn-sm{height:34px;padding:0 12px;font-size:.84rem}.icon-btn{background:none;border:0;padding:8px;border-radius:8px;cursor:pointer;font-size:1.2rem;display:inline-flex}.icon-btn:hover{background:var(--surface-2)}.spinner{display:inline-block;width:18px;height:18px;border:2px solid rgba(255,255,255,.25);border-top-color:#fff;border-radius:50%;animation:spin .7s linear infinite;vertical-align:middle}.spinner-lg{width:34px;height:34px;border-width:3px;border-color:var(--surface-3);border-top-color:var(--accent-2)}@keyframes spin{to{transform:rotate(360deg)}}@keyframes 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h1{font-size:2rem}.auth-brand{margin-bottom:28px}.field{display:grid;gap:8px;margin:26px 0 16px}.field span{font-size:.84rem;font-weight:600;color:var(--text-2)}.field input,.code-inputs input{background:var(--surface);border:1px solid var(--border-2);border-radius:var(--radius-sm);color:var(--text);font:inherit;outline:none;transition:border-color .15s,box-shadow .15s,background .15s}.field input{height:52px;padding:0 16px;font-size:1rem}.field input:focus,.code-inputs input:focus{border-color:var(--accent-2);box-shadow:0 0 0 4px #2fc4ff26;background:var(--surface-2)}.code-inputs{display:grid;grid-template-columns:repeat(6,1fr);gap:10px;margin:30px 0 18px}.code-inputs input{height:64px;width:100%;text-align:center;font-family:var(--display);font-size:1.7rem;font-weight:700;padding:0}.auth-actions{display:flex;justify-content:space-between;gap:8px;margin-top:14px}.form-error{color:var(--danger);font-size:.9rem;background:#ff6b7a14;border:1px solid rgba(255,107,122,.25);padding:10px 12px;border-radius:9px}.demo-note{margin:26px 0 0;font-size:.84rem;text-align:center;color:var(--accent-2);padding:10px;border-radius:10px;background:var(--accent-soft)}.auth-help{margin:18px 0 0;font-size:.85rem;text-align:center}.auth-help a{color:var(--text);text-decoration:underline}.auth-foot{color:var(--muted);font-size:.78rem;margin:0}.topbar{position:sticky;top:0;z-index:30;height:var(--topbar);display:flex;align-items:center;gap:36px;padding:0 28px;background:#05070db8;backdrop-filter:saturate(160%) blur(16px);border-bottom:1px solid var(--border)}.brand{display:flex;align-items:center}.topnav{display:flex;gap:4px;flex:1}.topnav a{padding:8px 14px;border-radius:9px;color:var(--muted);font-weight:500;font-size:.92rem;transition:color .15s,background .15s}.topnav a.active,.topnav a:hover{color:var(--text);background:var(--surface-2)}.account{position:relative}.avatar{width:38px;height:38px;border-radius:50%;border:0;background:linear-gradient(135deg,var(--accent-2),var(--accent));color:#fff;font-family:var(--display);font-weight:700;cursor:pointer;box-shadow:0 0 0 2px var(--bg),0 0 0 3px #2fc4ff66}.dropdown{position:absolute;right:0;top:50px;width:270px;background:var(--surface);border:1px solid var(--border-2);border-radius:var(--radius);padding:6px;box-shadow:var(--shadow);animation:rise .18s ease both}.dropdown-head{display:grid;padding:10px 12px 12px;border-bottom:1px solid var(--border);margin-bottom:6px;word-break:break-all}.dropdown-item{display:flex;width:100%;align-items:center;gap:10px;padding:10px 12px;border-radius:9px;background:none;border:0;cursor:pointer;text-align:left;font-size:.92rem}.dropdown-item:hover{background:var(--surface-2)}.demo-banner{background:var(--accent-soft);color:#a9cfff;text-align:center;font-size:.8rem;padding:6px 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.2s}.resume:hover{border-color:#2fc4ff73;transform:translateY(-2px);box-shadow:var(--shadow)}.resume-cover{aspect-ratio:16 / 9;border-radius:13px;background:var(--surface-3) center / cover;display:grid;place-items:center;position:relative;overflow:hidden}.resume-cover:after{content:"";position:absolute;inset:0;background:#05070d40}.resume-play{position:relative;z-index:1;width:56px;height:56px;border-radius:50%;display:grid;place-items:center;font-size:1.3rem;color:#fff;background:#1f6bffe6;box-shadow:var(--glow);transition:transform .2s}.resume:hover .resume-play{transform:scale(1.08)}.resume-body h2{font-size:1.35rem;margin-bottom:6px}.resume-body .progress{max-width:420px;margin-top:14px}.resume-cta{display:inline-flex;align-items:center;gap:6px;font-weight:600;color:var(--accent-2)}.course-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(350px,1fr));gap:24px}.course-card{position:relative;background:var(--surface);border:1px solid var(--border);border-radius:20px;overflow:hidden;display:flex;flex-direction:column;transition:border-color .25s,transform .25s,box-shadow .25s}.course-card:hover{border-color:var(--border-2);transform:translateY(-4px);box-shadow:var(--shadow)}.course-cover{position:relative;aspect-ratio:16 / 8.5;background:radial-gradient(80% 120% at 0% 0%,rgba(31,107,255,.55),transparent 60%),radial-gradient(80% 120% at 100% 100%,rgba(47,196,255,.4),transparent 60%),var(--surface-2);background-size:cover;background-position:center;display:flex;align-items:flex-end;justify-content:space-between;padding:16px;overflow:hidden}.course-cover:after{content:"";position:absolute;inset:55% 0 0;background:linear-gradient(transparent,var(--surface))}.course-cover .chip{position:absolute;top:14px;left:14px;z-index:1}.cover-title{position:relative;z-index:1;font-family:var(--display);font-size:1.6rem;font-weight:700}.course-body{padding:4px 24px 24px;display:flex;flex-direction:column;gap:4px;flex:1}.meta{display:flex;align-items:center;gap:8px;color:var(--muted);font-size:.86rem;margin:4px 0 12px}.course-actions{display:flex;gap:8px;margin-top:auto;padding-top:20px}.empty{text-align:center;padding:64px 24px}.progress{display:flex;align-items:center;gap:12px}.progress-bar{flex:1;height:6px;background:var(--surface-3);border-radius:99px;overflow:hidden}.progress-bar span{display:block;height:100%;background:linear-gradient(90deg,var(--accent),var(--accent-2));border-radius:inherit;box-shadow:0 0 12px #2fc4ff99;transition:width .5s ease}.progress-label{font-size:.8rem;font-weight:600;color:var(--text-2);min-width:36px;text-align:right;font-variant-numeric:tabular-nums}.course-hero{position:relative;overflow:hidden;margin-top:-40px;padding:56px 0 48px;border-bottom:1px solid var(--border)}.course-hero-bg{position:absolute;inset:0;background-size:cover;background-position:center 30%;opacity:.35;filter:blur(2px) saturate(1.1);transform:scale(1.04)}.course-hero:after{content:"";position:absolute;inset:0;background:linear-gradient(90deg,var(--bg) 25%,rgba(5,7,13,.65) 65%,rgba(5,7,13,.35)),linear-gradient(transparent 50%,var(--bg))}.course-hero-inner{position:relative;z-index:1;display:grid;grid-template-columns:1fr 360px;gap:48px;align-items:end}.hero-title{font-size:clamp(2.1rem,5vw,3.6rem);letter-spacing:-.04em;margin-bottom:14px}.lead{font-size:1.1rem;color:var(--text-2);max-width:620px}.stats{display:flex;flex-wrap:wrap;gap:10px;margin-top:22px}.stats span{display:inline-flex;align-items:center;gap:8px;color:var(--text-2);font-size:.86rem;font-weight:500;padding:7px 13px;border-radius:99px;background:#0d111cb3;border:1px solid var(--border-2);backdrop-filter:blur(8px)}.course-hero-card{background:#0d111cbf;backdrop-filter:blur(18px);border:1px solid var(--border-2);border-radius:20px;padding:24px;display:grid;gap:18px;box-shadow:var(--shadow)}.course-hero-card p{margin:0}.hero-card-top{display:flex;align-items:center;gap:18px}.big-number{font-family:var(--display);font-size:2rem;font-weight:700;letter-spacing:-.03em;line-height:1.1}.big-number span{font-size:1rem;color:var(--muted);font-weight:600}.next-label{margin-top:-6px!important;text-align:center}.outline{display:grid;gap:10px}.outline-big{gap:12px}.group{border:1px solid var(--border);border-radius:var(--radius);background:var(--surface);overflow:hidden;transition:border-color .2s}.group.open{border-color:var(--border-2)}.group.depth-1,.group.depth-2{border:0;border-radius:0;background:transparent;border-top:1px solid var(--border)}.group-head{width:100%;display:flex;align-items:center;gap:14px;padding:16px 18px;background:none;border:0;cursor:pointer;text-align:left;transition:background .15s}.group-head:hover{background:var(--surface-2)}.group-head>.icon{transition:transform 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var(--border-2)}.depth-1>.group-head{padding-left:28px}.depth-2>.group-head{padding-left:42px}.depth-1>.group-head .group-title,.depth-2>.group-head .group-title{font-family:Inter,sans-serif;font-weight:600;font-size:.92rem;color:var(--text-2)}.group-count{display:inline-flex;align-items:center;gap:4px;font-size:.76rem;font-weight:600;color:var(--muted);background:var(--surface-2);border:1px solid var(--border);padding:3px 10px;border-radius:99px;font-variant-numeric:tabular-nums}.group-count.complete{color:var(--success);background:var(--success-soft);border-color:#2ee59d40}.group-body{border-top:1px solid var(--border);background:#05070d40}.lesson-list{list-style:none;margin:0;padding:6px}.lesson-row{display:flex;align-items:center;gap:12px;padding:10px 12px;border-radius:10px;font-size:.92rem;color:var(--text-2);transition:background .15s,color .15s}.lesson-row:hover{background:var(--surface-2);color:var(--text)}.lesson-row.current{background:linear-gradient(90deg,#1f6bff33,#1f6bff0d);color:var(--text);box-shadow:inset 2px 0 0 var(--accent-2)}.lesson-status{width:22px;height:22px;flex:none;border-radius:50%;border:1.5px solid var(--border-2);display:grid;place-items:center;font-size:.72rem;transition:background .2s,border-color .2s}.done .lesson-status{background:var(--success);border-color:var(--success);color:#03150d}.current .lesson-status{border-color:var(--accent-2);color:var(--accent-2)}.done.current .lesson-status{color:#03150d}.lesson-title{flex:1;min-width:0}.done .lesson-title{color:var(--muted)}.lesson-meta{display:inline-flex;align-items:center;gap:10px;color:var(--muted);font-size:.8rem;font-variant-numeric:tabular-nums}.lesson-layout{display:grid;grid-template-columns:350px 1fr;min-height:calc(100vh - var(--topbar))}.lesson-sidebar{position:sticky;top:var(--topbar);height:calc(100vh - var(--topbar));overflow-y:auto;border-right:1px solid var(--border);background:#080b14d9;padding:22px 14px 40px;scrollbar-width:thin;scrollbar-color:var(--surface-3) transparent}.sidebar-head{display:flex;align-items:center;justify-content:space-between}.sidebar-head .back{margin:0 0 0 6px;font-weight:600;color:var(--text);font-family:var(--display)}.sidebar-progress{display:grid;gap:8px;padding:16px 6px 20px}.lesson-sidebar .group{background:transparent}.lesson-sidebar .group-head{padding:12px 14px}.lesson-sidebar .group-title{font-size:.95rem}.lesson-sidebar .lesson-row{font-size:.86rem;padding:8px 10px}.lesson-main{padding:32px clamp(20px,4vw,60px) 96px;max-width:1100px;width:100%;margin:0 auto;min-width:0}.player{position:relative;aspect-ratio:16 / 9;background:#000;border-radius:18px;overflow:hidden;border:1px solid var(--border-2);box-shadow:0 40px 100px -40px #1f6bff73,var(--shadow);margin-bottom:30px}.player iframe{width:100%;height:100%;border:0;display:block}.player-msg{height:100%;display:grid;place-content:center;justify-items:center;gap:16px;text-align:center;padding:24px;color:var(--muted);background:radial-gradient(45% 60% at 50% 50%,rgba(31,107,255,.2),transparent 70%),#03050a}.player-msg p{max-width:380px;margin:0;font-size:.92rem}.player-icon{width:72px;height:72px;border-radius:50%;display:grid;place-items:center;font-size:1.7rem;color:#fff;background:linear-gradient(180deg,#3d82ff,var(--accent));box-shadow:var(--glow)}.lesson-head{display:flex;justify-content:space-between;align-items:flex-start;gap:24px;margin-bottom:26px}.lesson-head h1{font-size:clamp(1.5rem,2.8vw,2.1rem)}.lesson-head p{margin:0}.prose{margin-bottom:20px;color:var(--text-2);font-size:1rem;line-height:1.75;overflow-wrap:anywhere}.prose strong,.prose b{color:var(--text)}.prose a{color:var(--accent-2);text-decoration:underline;text-decoration-color:#2fc4ff66;text-underline-offset:3px}.prose a:hover{text-decoration-color:var(--accent-2)}.prose img{max-width:100%;height:auto;border-radius:10px}.prose ul,.prose ol{padding-left:1.3em}.prose>:last-child{margin-bottom:0}.resources{margin-bottom:20px}.resources h2{font-size:1.05rem;margin-bottom:14px}.resources ul{list-style:none;margin:0;padding:0;display:grid;gap:8px}.resources li{display:flex;align-items:center;gap:12px;padding:10px 12px;background:var(--bg-2);border:1px solid var(--border);border-radius:var(--radius-sm);transition:border-color .15s}.resources li:hover{border-color:var(--border-2)}.file-icon{width:38px;height:38px;border-radius:10px;display:grid;place-items:center;background:var(--accent-soft);color:var(--accent-2);font-size:1.1rem;flex:none}.file-name{flex:1;min-width:0;font-weight:500;font-size:.92rem;overflow-wrap:anywhere}.lesson-nav{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin-top:34px}.nav-card{display:grid;gap:4px;padding:18px 20px;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);text-align:left;cursor:pointer;font-weight:600;font-family:var(--display);transition:border-color .2s,transform .2s;min-width:0}.nav-card:hover{border-color:var(--accent-2);transform:translateY(-2px)}.nav-card .muted{display:inline-flex;align-items:center;gap:4px;font-weight:500;font-family:Inter,sans-serif}.nav-card.next{text-align:right;justify-items:end;background:linear-gradient(120deg,#1f6bff38,#2fc4ff0f),var(--surface);border-color:#2fc4ff40}.only-mobile,.scrim{display:none}.account-card{display:grid;gap:0;padding:8px 24px;margin:16px 0 24px}.account-card .row{display:flex;justify-content:space-between;gap:16px;padding:15px 0;border-bottom:1px solid var(--border)}.account-card .row:last-child{border:0}@media(max-width:1020px){.auth{grid-template-columns:1fr}.auth-showcase{display:none}.auth-panel .only-mobile{display:block}.course-hero-inner{grid-template-columns:1fr;gap:28px}.resume{grid-template-columns:220px 1fr}.resume-cta{display:none}.lesson-layout{grid-template-columns:1fr}.lesson-sidebar{position:fixed;z-index:50;top:0;left:0;bottom:0;height:100vh;width:min(370px,88vw);transform:translate(-100%);transition:transform .28s ease;background:var(--bg-2)}.lesson-sidebar.open{transform:none;box-shadow:var(--shadow)}.scrim{display:block;position:fixed;inset:0;z-index:40;background:#0009;backdrop-filter:blur(2px)}.only-mobile{display:inline-flex}.outline-toggle{margin-bottom:16px;border:1px solid var(--border-2)}}@media(max-width:640px){.container{padding:0 16px}.page{padding-top:26px}.topbar{padding:0 16px;gap:12px;height:60px}:root{--topbar: 60px}.topbar .logo{height:30px!important}.topnav{visibility:hidden}.welcome{flex-direction:column;align-items:stretch}.resume{grid-template-columns:1fr;padding:12px;gap:16px}.resume-body{padding:0 8px 8px}.course-grid{grid-template-columns:1fr}.course-actions{flex-wrap:wrap}.course-actions .btn{flex:1}.course-hero{margin-top:-26px;padding:36px 0 32px}.group-thumb{width:84px}.rich>.group-head{gap:12px;padding-right:14px}.group-bar{display:none}.code-inputs{gap:6px}.code-inputs input{height:56px;font-size:1.4rem}.lesson-main{padding:16px 16px 64px}.player{border-radius:14px;margin-bottom:22px}.lesson-head{flex-direction:column;gap:16px}.lesson-head .btn{width:100%}.lesson-nav{grid-template-columns:1fr}.resources li{flex-wrap:wrap}.card{padding:18px}}