:root {
  --bg:#000; --bg-elevated:#060608; --bg-card:#0f1014; --bg-deep:#050507;
  --border:#1c1c1f; --border-strong:#2a2a2e;
  --text:#f5f5f7; --text-dim:#98989d; --text-faint:#6e6e73;
  --accent:#c779ff; --accent-2:#ff5ea0; --accent-3:#ff8a3d;
  --red:#ff5252; --green:#34d399;
  --gradient:linear-gradient(135deg,#c779ff 0%,#ff5ea0 50%,#ff8a3d 100%);
  --gradient-text:linear-gradient(135deg,#c779ff 0%,#ff5ea0 100%);
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;-webkit-font-smoothing:antialiased}
body{font-family:'Inter',-apple-system,sans-serif;background:var(--bg);color:var(--text);line-height:1.6;letter-spacing:-0.011em;overflow-x:hidden;min-height:100vh}
body::before{content:'';position:fixed;inset:0;background:radial-gradient(ellipse at center,rgba(0,0,0,0) 0%,rgba(0,0,0,0.55) 100%);pointer-events:none;z-index:1}
::selection{background:rgba(199,121,255,0.4);color:#fff}
a{color:inherit;text-decoration:none}
.aurora-bg{position:fixed;inset:0;z-index:0;pointer-events:none;overflow:hidden;filter:blur(160px) saturate(1.1);opacity:0.16}
.aurora-blob{position:absolute;border-radius:50%;mix-blend-mode:screen;will-change:transform}
.aurora-blob.b1{width:600px;height:600px;background:radial-gradient(circle,#c779ff 0%,transparent 70%);top:-200px;left:-100px;animation:float-1 25s ease-in-out infinite}
.aurora-blob.b2{width:500px;height:500px;background:radial-gradient(circle,#ff5ea0 0%,transparent 70%);top:30vh;right:-150px;animation:float-2 30s ease-in-out infinite}
.aurora-blob.b3{width:700px;height:700px;background:radial-gradient(circle,#ff8a3d 0%,transparent 70%);bottom:-200px;left:30%;animation:float-3 35s ease-in-out infinite}
@keyframes float-1{0%,100%{transform:translate(0,0) scale(1)}50%{transform:translate(40vw,30vh) scale(1.2)}}
@keyframes float-2{0%,100%{transform:translate(0,0) scale(1)}50%{transform:translate(-30vw,50vh) scale(0.9)}}
@keyframes float-3{0%,100%{transform:translate(0,0) scale(1)}50%{transform:translate(-20vw,-30vh) scale(1.3)}}
.reading-progress{position:fixed;top:0;left:0;width:100%;height:3px;z-index:100;pointer-events:none}
.reading-progress-bar{height:100%;background:var(--gradient);width:0;box-shadow:0 0 16px rgba(199,121,255,0.7)}

.layout{display:grid;grid-template-columns:300px 1fr;min-height:100vh;position:relative;z-index:2}
.sidebar{position:sticky;top:0;height:100vh;border-right:1px solid var(--border);background:rgba(0,0,0,0.72);backdrop-filter:blur(24px);-webkit-backdrop-filter:blur(24px);padding:36px 26px 24px;overflow-y:auto;z-index:40;display:flex;flex-direction:column}
.sidebar::-webkit-scrollbar{width:4px}.sidebar::-webkit-scrollbar-thumb{background:var(--border-strong);border-radius:2px}
.sidebar-header{margin-bottom:18px;padding-bottom:18px;border-bottom:1px solid var(--border)}
.sidebar-eyebrow{font-size:10px;font-weight:700;letter-spacing:0.16em;text-transform:uppercase;background:var(--gradient-text);-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent;margin-bottom:8px}
.sidebar-title{font-size:17px;font-weight:800;line-height:1.2;letter-spacing:-0.02em}
.sidebar-title a:hover{opacity:.85}
.progress-pill{margin-top:14px}
.progress-track{height:5px;background:var(--border);border-radius:99px;overflow:hidden}
.progress-fill{height:100%;background:var(--gradient);border-radius:99px;width:0;transition:width .4s ease}
.progress-txt{font-size:11px;color:var(--text-dim);margin-top:6px}
.search-box{margin:4px 0 6px;position:relative}
.search-box input{width:100%;background:var(--bg-card);border:1px solid var(--border-strong);border-radius:10px;color:var(--text);font-family:inherit;font-size:13px;padding:9px 12px 9px 32px;outline:none;transition:border .2s}
.search-box input:focus{border-color:var(--accent)}
.search-box::before{content:'⌕';position:absolute;left:11px;top:7px;color:var(--text-faint);font-size:15px}
.nav-list{list-style:none;flex:1}
.nav-section{font-size:9px;font-weight:800;letter-spacing:0.18em;text-transform:uppercase;color:var(--text-faint);margin:20px 0 6px;position:relative;padding-left:16px}
.nav-section::before{content:'';position:absolute;left:0;top:50%;transform:translateY(-50%);width:8px;height:1px;background:var(--gradient)}
.nav-item a{display:flex;align-items:center;gap:8px;padding:6px 0 6px 16px;margin-left:-16px;color:var(--text-dim);font-size:12.5px;transition:all .2s ease;border-left:1px solid transparent;line-height:1.35}
.nav-item a:hover{color:var(--text)}
.nav-item a.active{color:var(--text);border-left-color:var(--accent);font-weight:600;background:linear-gradient(90deg,rgba(199,121,255,0.1),transparent)}
.nav-num{font-family:'JetBrains Mono',monospace;font-size:10px;color:var(--text-faint);min-width:18px}
.nav-item a.done .nav-num{color:var(--green)}
.nav-check{margin-left:auto;font-size:11px;color:var(--green);opacity:0;flex:none}
.nav-item a.done .nav-check{opacity:1}

main{max-width:880px;margin:0 auto;padding:64px 56px 140px;position:relative;z-index:2;width:100%}
.crumb{font-size:11px;font-weight:700;letter-spacing:0.14em;text-transform:uppercase;color:var(--text-faint);margin-bottom:18px;display:flex;gap:10px;align-items:center}
.crumb b{background:var(--gradient-text);-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent}
.lesson-title{font-size:clamp(34px,4.6vw,52px);font-weight:900;letter-spacing:-0.04em;line-height:1.04;margin-bottom:22px}
.meta-row{display:flex;flex-wrap:wrap;gap:10px;margin-bottom:44px}
.meta-chip{font-size:11.5px;font-weight:600;color:var(--text-dim);border:1px solid var(--border-strong);background:rgba(15,16,20,0.6);padding:7px 14px;border-radius:99px}
.meta-chip b{color:var(--text)}

.prose{font-size:16.5px;line-height:1.75;color:#d6d6da}
.prose h1{font-size:30px;font-weight:850;letter-spacing:-0.03em;line-height:1.15;margin:64px 0 20px;color:var(--text);padding-top:18px;border-top:1px solid var(--border)}
.prose h2{font-size:24px;font-weight:800;letter-spacing:-0.025em;margin:56px 0 16px;color:var(--text);position:relative;padding-left:18px}
.prose h2::before{content:'';position:absolute;left:0;top:6px;bottom:6px;width:3.5px;border-radius:4px;background:var(--gradient)}
.prose h3{font-size:18.5px;font-weight:750;margin:40px 0 12px;color:var(--text)}
.prose h4{font-size:16px;font-weight:700;margin:30px 0 10px;color:var(--text)}
.prose p{margin:0 0 18px}
.prose strong{color:var(--text);font-weight:700}
.prose ul,.prose ol{margin:0 0 20px;padding-left:26px}
.prose li{margin-bottom:9px}
.prose li::marker{color:var(--accent)}
.prose hr{border:none;border-top:1px solid var(--border);margin:48px 0}
.prose a{color:var(--accent);border-bottom:1px solid rgba(199,121,255,0.35);transition:all .2s}
.prose a:hover{color:#fff;border-bottom-color:#fff}
.prose blockquote{border:1px solid var(--border-strong);background:rgba(15,16,20,0.65);border-radius:14px;padding:20px 24px;margin:0 0 22px;font-size:15px}
.prose blockquote p{margin-bottom:12px}.prose blockquote p:last-child{margin-bottom:0}
.prose blockquote em{color:var(--text-dim)}
.prose code{font-family:'JetBrains Mono',monospace;font-size:13.5px;background:var(--bg-card);border:1px solid var(--border);padding:2px 7px;border-radius:6px;color:var(--accent-2)}
.warn-p{border:1px solid rgba(255,138,61,0.4);background:rgba(255,138,61,0.07);border-radius:12px;padding:14px 18px}
.table-wrap{overflow-x:auto;margin:0 0 22px;border:1px solid var(--border-strong);border-radius:14px}
.prose table{border-collapse:collapse;width:100%;font-size:14px}
.prose th{text-align:left;font-size:11px;letter-spacing:.1em;text-transform:uppercase;color:var(--text-dim);padding:12px 16px;background:var(--bg-card);border-bottom:1px solid var(--border-strong)}
.prose td{padding:12px 16px;border-bottom:1px solid var(--border)}
.prose tr:last-child td{border-bottom:none}
li.todo{list-style:none;position:relative;padding-left:4px;margin-left:-12px;display:flex;gap:10px;align-items:baseline}
li.todo .cb{flex:none;width:15px;height:15px;border:1.5px solid var(--border-strong);border-radius:5px;display:inline-block;transform:translateY(2px)}
figure.shot{margin:26px 0;border:1px solid var(--border-strong);border-radius:16px;overflow:hidden;background:var(--bg-card)}
figure.shot img{display:block;width:100%;height:auto}
figure.shot.sm{max-width:340px}
figure.shot.md{max-width:520px}
.video-card{margin:30px 0;border:1px solid var(--border-strong);border-radius:18px;overflow:hidden;background:var(--bg-card)}
.video-head{display:flex;align-items:center;gap:12px;padding:14px 18px;border-bottom:1px solid var(--border)}
.video-chip{font-size:10px;font-weight:800;letter-spacing:0.1em;background:var(--gradient);color:#000;border-radius:99px;padding:4px 10px;flex:none}
.video-title{font-size:14px;font-weight:700;color:var(--text)}
.video-ext{margin-left:auto;font-size:11.5px;color:var(--text-faint);flex:none}
.video-ext:hover{color:var(--accent)}
.video-frame{position:relative;padding-bottom:56.25%;height:0}
.video-frame iframe{position:absolute;inset:0;width:100%;height:100%}
.diagram{margin:34px 0;border:1px solid var(--border-strong);border-radius:18px;background:rgba(15,16,20,0.5);padding:22px 22px 14px}
.diagram svg{width:100%;height:auto;display:block}
.diagram-label{font-size:10px;font-weight:800;letter-spacing:0.16em;text-transform:uppercase;background:var(--gradient-text);-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent;margin-bottom:12px}
.supl-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:14px;margin:24px 0}
.supl-card{border:1px solid var(--border-strong);border-radius:14px;background:var(--bg-card);padding:18px}
.supl-name{font-weight:800;font-size:15px;margin-bottom:10px;background:var(--gradient-text);-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent}
.supl-row{font-size:12.5px;color:var(--text-dim);margin-bottom:8px;line-height:1.5}
.supl-row b{color:var(--text)}
.supl-link{font-size:11.5px;color:var(--accent-3);font-weight:600}
.ejemplo{border:1px solid var(--border-strong);background:rgba(15,16,20,0.65);border-radius:14px;padding:18px 22px 20px;margin:0 0 22px}
.ejemplo-head{font-size:11px;font-weight:800;letter-spacing:.12em;text-transform:uppercase;background:var(--gradient-text);-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent;margin-bottom:14px}
.ejemplo-head .nota{font-weight:500;letter-spacing:0;text-transform:none;-webkit-text-fill-color:var(--text-faint);color:var(--text-faint)}
.ejemplo-sub{font-weight:700;color:var(--text);font-size:13.5px;margin:18px 0 9px}
.ejemplo-sub:first-of-type{margin-top:4px}
.ejemplo ul{margin:0;padding-left:24px}
.ejemplo li{margin-bottom:9px;font-size:14px;line-height:1.55;color:var(--text-dim)}
.ejemplo li::marker{color:var(--accent)}
.ejemplo li b,.ejemplo li strong{color:var(--text);font-weight:700}
.ejemplo .cierre{font-size:13.5px;color:var(--text-dim);line-height:1.65;margin-top:14px}

.lesson-end{margin-top:72px;border-top:1px solid var(--border);padding-top:36px}
.complete-btn{display:inline-flex;align-items:center;gap:10px;font-family:inherit;font-size:14px;font-weight:800;letter-spacing:-0.01em;padding:14px 28px;border-radius:99px;border:1px solid var(--border-strong);background:var(--bg-card);color:var(--text);cursor:pointer;transition:all .25s}
.complete-btn:hover{border-color:var(--accent)}
.complete-btn.done{background:var(--gradient);color:#000;border-color:transparent}
.pn-grid{display:grid;grid-template-columns:1fr 1fr;gap:14px;margin-top:28px}
.pn-card{border:1px solid var(--border-strong);border-radius:16px;background:rgba(15,16,20,0.6);padding:18px 20px;transition:all .25s;display:block}
.pn-card:hover{border-color:var(--accent);transform:translateY(-2px)}
.pn-label{font-size:10px;font-weight:800;letter-spacing:0.14em;text-transform:uppercase;color:var(--text-faint);margin-bottom:8px}
.pn-title{font-size:14.5px;font-weight:700;line-height:1.3}
.pn-card.next .pn-label{background:var(--gradient-text);-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent}

/* ===== HOME ===== */
.hero{padding:30px 0 14px;margin-bottom:34px}
.hero-eyebrow{display:inline-flex;align-items:center;gap:12px;font-size:11px;font-weight:700;letter-spacing:0.16em;text-transform:uppercase;color:var(--text-dim);padding:9px 16px;border:1px solid var(--border-strong);border-radius:999px;background:rgba(255,255,255,0.03);margin-bottom:28px}
.hero-eyebrow::before{content:'';width:8px;height:8px;border-radius:50%;background:var(--gradient);box-shadow:0 0 16px var(--accent);animation:pulse 2s ease-in-out infinite}
@keyframes pulse{0%,100%{box-shadow:0 0 16px var(--accent)}50%{box-shadow:0 0 32px var(--accent),0 0 48px var(--accent-2)}}
.hero h1{font-size:clamp(44px,6.4vw,76px);font-weight:900;letter-spacing:-0.05em;line-height:0.98;margin-bottom:24px}
.hero h1 .gradient{background:var(--gradient);-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent}
.hero-sub{font-size:clamp(17px,2vw,20px);color:var(--text-dim);line-height:1.5;max-width:660px;margin-bottom:34px}
.hero-cta{display:flex;gap:12px;flex-wrap:wrap;margin-bottom:46px}
.cta-primary{display:inline-flex;align-items:center;gap:10px;font-size:15px;font-weight:800;letter-spacing:-0.01em;padding:15px 30px;border-radius:99px;background:var(--gradient);color:#000;transition:transform .25s ease,box-shadow .25s ease}
.cta-primary:hover{transform:translateY(-2px);box-shadow:0 14px 34px rgba(199,121,255,0.32)}
.stats-row{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:1px;background:var(--border);border:1px solid var(--border);border-radius:18px;overflow:hidden;margin-bottom:54px}
.stat-item{padding:20px 24px;background:rgba(15,16,20,0.6)}
.stat-num{font-size:26px;font-weight:900;letter-spacing:-0.03em;background:var(--gradient-text);-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent}
.stat-lbl{font-size:10.5px;font-weight:700;letter-spacing:0.12em;text-transform:uppercase;color:var(--text-faint);margin-top:4px}
.block-section{margin-bottom:50px}
.block-head{display:flex;align-items:center;gap:16px;margin-bottom:20px}
.block-badge{width:46px;height:46px;border-radius:14px;display:grid;place-items:center;font-family:'JetBrains Mono',monospace;font-size:17px;font-weight:700;color:#000;background:var(--gradient);flex:none;box-shadow:0 8px 22px rgba(199,121,255,0.22)}
.block-info{flex:1;min-width:0}
.block-eyebrow{font-size:10px;font-weight:800;letter-spacing:0.16em;text-transform:uppercase;color:var(--text-faint);margin-bottom:3px}
.block-title{font-size:21px;font-weight:800;letter-spacing:-0.02em;line-height:1.1}
.block-prog{display:flex;flex-direction:column;align-items:flex-end;gap:6px;flex:none}
.block-prog-track{width:84px;height:5px;background:var(--border);border-radius:99px;overflow:hidden}
.block-prog-fill{height:100%;width:0;background:var(--gradient);border-radius:99px;transition:width .45s ease}
.block-prog-txt{font-family:'JetBrains Mono',monospace;font-size:10.5px;font-weight:700;color:var(--text-faint)}
.lesson-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:14px}
.lesson-card{display:flex;flex-direction:column;border:1px solid var(--border-strong);background:rgba(15,16,20,0.55);border-radius:18px;padding:22px 24px;transition:transform .22s ease,border-color .22s ease,box-shadow .22s ease;position:relative;overflow:hidden;min-height:158px}
.lesson-card::after{content:'';position:absolute;left:0;right:0;top:0;height:2px;background:var(--gradient);transform:scaleX(0);transform-origin:left;transition:transform .3s ease}
.lesson-card:hover{border-color:var(--accent);transform:translateY(-3px);box-shadow:0 18px 40px rgba(0,0,0,0.45)}
.lesson-card:hover::after{transform:scaleX(1)}
.lc-top{display:flex;align-items:center;justify-content:space-between;margin-bottom:15px}
.lc-num{font-family:'JetBrains Mono',monospace;font-size:21px;font-weight:700;letter-spacing:-0.02em;background:var(--gradient-text);-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent}
.lesson-card.done .lc-num{background:none;-webkit-text-fill-color:var(--green)}
.lc-check{flex:none;width:24px;height:24px;border-radius:50%;border:1.5px solid var(--border-strong);display:grid;place-items:center;font-size:12px;color:transparent;transition:all .2s}
.lesson-card.done{border-color:rgba(80,220,150,0.35)}
.lesson-card.done .lc-check{background:var(--gradient);border-color:transparent;color:#000;font-weight:900}
.lc-title{font-size:16.5px;font-weight:750;letter-spacing:-0.015em;line-height:1.25;margin-bottom:8px}
.lc-desc{font-size:13px;color:var(--text-dim);line-height:1.5;flex:1}
.lc-foot{margin-top:16px;display:flex;align-items:center;gap:8px}
.lc-badge{display:inline-flex;align-items:center;gap:6px;font-size:10.5px;font-weight:700;letter-spacing:0.04em;color:var(--text-faint);border:1px solid var(--border-strong);border-radius:99px;padding:4px 11px}

/* search overlay */
.search-results{position:absolute;top:42px;left:0;right:0;background:var(--bg-elevated);border:1px solid var(--border-strong);border-radius:14px;max-height:50vh;overflow-y:auto;z-index:60;display:none;box-shadow:0 24px 64px rgba(0,0,0,0.7)}
.search-results.open{display:block}
.sr-item{display:block;padding:12px 16px;border-bottom:1px solid var(--border)}
.sr-item:last-child{border-bottom:none}
.sr-item:hover{background:rgba(199,121,255,0.08)}
.sr-title{font-size:13px;font-weight:700}
.sr-ctx{font-size:11.5px;color:var(--text-dim);margin-top:3px;line-height:1.45}
.sr-ctx mark{background:rgba(199,121,255,0.3);color:#fff;border-radius:3px;padding:0 2px}
.sr-empty{padding:14px 16px;font-size:12.5px;color:var(--text-faint)}

.menu-btn{display:none;position:fixed;top:14px;left:14px;z-index:90;background:var(--bg-elevated);border:1px solid var(--border-strong);color:var(--text);width:42px;height:42px;border-radius:12px;font-size:18px;cursor:pointer}
@media (max-width:1080px){
  .layout{grid-template-columns:1fr}
  .sidebar{position:fixed;left:0;top:0;width:300px;transform:translateX(-100%);transition:transform .3s ease;box-shadow:24px 0 64px rgba(0,0,0,0.6)}
  .sidebar.open{transform:translateX(0)}
  .menu-btn{display:block}
  main{padding:80px 22px 120px}
  .pn-grid,.lesson-grid{grid-template-columns:1fr}
}
@media print{.sidebar,.menu-btn,.reading-progress,.aurora-bg{display:none!important}.layout{grid-template-columns:1fr}body{background:#fff;color:#000}}