:root{--bg:#0f172a;--panel:#111827;--card:#1e293b;--card-alt:#172233;--muted:#94a3b8;--text:#e5e7eb;--primary:#22c55e;--danger:#ef4444;--border:#334155;--accent:#60a5fa;--gold:#fbbf24}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;font-family:Arial,sans-serif;background:radial-gradient(circle at top,#122444 0%,#0b1325 42%,#09111f 100%);color:var(--text)}
a{color:#93c5fd;text-decoration:none}
a:hover{text-decoration:none;opacity:.95}
img{max-width:100%;display:block}
code{background:#0b1220;padding:.15rem .35rem;border-radius:6px}
video{border-radius:20px;background:#000;width:100%;box-shadow:0 20px 40px rgba(0,0,0,.25)}
.container{max-width:1260px;margin:0 auto;padding:0 18px}.narrow{max-width:760px}.page{padding-block:24px}
.topbar{background:#020617;border-bottom:1px solid var(--border);position:sticky;top:0;z-index:30;backdrop-filter:blur(16px)}
.flex{display:flex}.between{justify-content:space-between}.center{align-items:center}
.brand{font-weight:700;color:#fff;padding:18px 0;display:block;font-size:1.08rem}.nav a{margin-left:14px;color:#cbd5e1}
.card{background:linear-gradient(180deg,rgba(30,41,59,.96),rgba(22,32,48,.98));border:1px solid rgba(71,85,105,.65);border-radius:22px;padding:22px;margin-bottom:18px;box-shadow:0 18px 50px rgba(2,6,23,.24)}
.card.flat{padding:0;overflow:hidden}
.grid{display:grid;gap:18px}.courses-grid{grid-template-columns:repeat(auto-fill,minmax(300px,1fr))}.stats-grid{grid-template-columns:repeat(auto-fit,minmax(160px,1fr))}
.stat-card span{display:block;font-size:2rem;margin-top:8px}.course-card h3{margin:0 0 10px 0;font-size:1.18rem}.course-card p{color:#cbd5e1}
.course-cover,.hero-cover,.dashboard-cover{position:relative;overflow:hidden;background:linear-gradient(135deg,#12213d,#1d4ed8)}
.course-cover{height:210px;border-radius:18px;margin:-2px -2px 18px -2px}
.dashboard-cover{width:132px;height:96px;border-radius:18px;flex:0 0 132px}
.hero-cover{width:240px;height:170px;border-radius:20px;flex:0 0 240px}
.cover-image{width:100%;height:100%;object-fit:cover}
.cover-placeholder{width:100%;height:100%;display:flex;align-items:flex-end;padding:18px;background:linear-gradient(135deg,rgba(96,165,250,.18),rgba(34,197,94,.12));font-weight:700;font-size:1.1rem;color:#fff}
.cover-badge{position:absolute;top:14px;left:14px;padding:8px 12px;border-radius:999px;background:rgba(2,6,23,.68);border:1px solid rgba(148,163,184,.26);font-size:.84rem;font-weight:700}
.course-meta-row{display:flex;gap:10px;flex-wrap:wrap;color:var(--muted);font-size:.92rem}
.course-hero-layout{display:flex;gap:22px;align-items:stretch;flex-wrap:wrap}.course-hero-content{flex:1 1 420px;min-width:280px}.course-hero h1{margin:0 0 12px 0;font-size:2.15rem;line-height:1.08}.course-subtitle{margin:0;color:#cbd5e1}.muted{color:var(--muted)}
.button,button{appearance:none;border:none;border-radius:14px;padding:12px 16px;background:var(--primary);color:#052e16;font-weight:700;cursor:pointer;display:inline-flex;justify-content:center;align-items:center;gap:8px;transition:transform .15s ease,opacity .15s ease,background .15s ease}.button:hover,button:hover{transform:translateY(-1px)}.button.secondary{background:#334155;color:#fff}.button.ghost{background:transparent;color:#cbd5e1;border:1px solid rgba(148,163,184,.24)}.button.disabled,.button[aria-disabled="true"]{background:#1f2937;color:#64748b;border:1px solid rgba(100,116,139,.35);pointer-events:none}
.actions{margin-top:14px;display:flex;gap:10px;flex-wrap:wrap}.split-actions{justify-content:space-between}
.form-grid{display:grid;gap:14px}.form-grid label{display:grid;gap:8px;font-size:.95rem}.form-grid input,.form-grid select{width:100%;padding:12px 14px;border-radius:10px;border:1px solid var(--border);background:#0f172a;color:#fff}
.narrow-card{max-width:480px;margin-inline:auto}.alert{padding:12px 14px;border-radius:12px;margin-bottom:18px}.alert.success{background:rgba(34,197,94,.15);border:1px solid rgba(34,197,94,.45)}.alert.error{background:rgba(239,68,68,.15);border:1px solid rgba(239,68,68,.45)}
.hero h1{margin-top:0;margin-bottom:8px}.hero p{margin:0;color:#cbd5e1}
.lesson-list{list-style:none;padding:0;margin:0;display:grid;gap:12px}.lesson-list li{display:flex;justify-content:space-between;align-items:center;padding:14px 0;border-bottom:1px solid rgba(71,85,105,.45)}
.lesson-list.rich li{gap:16px}.lesson-main{display:grid;gap:7px;min-width:0}.lesson-main strong{font-size:1rem;line-height:1.35}.lesson-status-line{display:flex;gap:8px;flex-wrap:wrap}.lesson-actions{display:flex;align-items:center;gap:10px;flex-wrap:wrap}
.status-badge,.module-badge,.completion-pill,.pill{display:inline-flex;align-items:center;gap:6px;padding:7px 12px;border-radius:999px;font-size:.88rem;font-weight:700}
.status-badge.done,.completion-pill.done,.pill.done{background:rgba(34,197,94,.16);color:#86efac;border:1px solid rgba(34,197,94,.34)}
.status-badge.partial,.pill.partial{background:rgba(96,165,250,.16);color:#bfdbfe;border:1px solid rgba(96,165,250,.34)}
.status-badge.idle,.pill.idle{background:rgba(148,163,184,.14);color:#cbd5e1;border:1px solid rgba(148,163,184,.28)}
.status-badge.locked,.pill.locked{background:rgba(251,191,36,.14);color:#fcd34d;border:1px solid rgba(251,191,36,.28)}
.module-head{display:flex;justify-content:space-between;gap:14px;align-items:flex-start;margin-bottom:14px}.module-head h2{margin:0 0 8px 0;font-size:1.22rem}.module-badge{background:rgba(96,165,250,.16);color:#bfdbfe;border:1px solid rgba(96,165,250,.34)}
.progress-box{margin-top:16px;background:rgba(15,23,42,.55);border:1px solid rgba(71,85,105,.6);border-radius:18px;padding:14px}.progress-box.compact{margin-top:10px}
.progress-meta{display:flex;justify-content:space-between;gap:12px;align-items:center;margin-bottom:8px}.progress-meta strong{font-size:.96rem}
.progress-track{height:10px;background:#0b1220;border-radius:999px;overflow:hidden}.progress-track span{display:block;height:100%;background:linear-gradient(90deg,var(--primary),#60a5fa);border-radius:999px}
.progress-box small{display:block;margin-top:8px;color:var(--muted)}
.watch-layout{display:grid;grid-template-columns:minmax(0,1.75fr) minmax(330px,.95fr);gap:18px;align-items:start}.watch-main{margin-bottom:0}.watch-sidebar{display:grid;gap:18px}.watch-sidebar .card{margin-bottom:0}
.sticky-stack{position:sticky;top:88px;display:grid;gap:18px}
.watch-header{display:flex;justify-content:space-between;gap:16px;align-items:flex-start;margin-bottom:14px}.watch-header h1{margin:0 0 8px 0;font-size:2rem;line-height:1.08}
.video-tools{display:flex;justify-content:space-between;gap:12px;align-items:center;flex-wrap:wrap;margin-top:14px}.video-actions{display:flex;gap:10px;flex-wrap:wrap}.lesson-progress-mini{display:grid;gap:4px;text-align:right}.lesson-progress-mini span{font-size:.92rem;color:var(--muted)}.lesson-progress-mini strong{font-size:1.1rem}
.material-list{list-style:none;padding:0;margin:0;display:grid;gap:10px}.material-list li{padding-bottom:10px;border-bottom:1px solid rgba(71,85,105,.45)}.stack-actions{display:grid;gap:10px}
.table{width:100%;border-collapse:collapse}.table th,.table td{padding:12px;border-bottom:1px solid var(--border);text-align:left;vertical-align:top}
.prose p:first-child{margin-top:0}.prose p:last-child{margin-bottom:0}
.sidebar-outline{display:grid;gap:14px}.sidebar-module{padding:16px;border-radius:18px;background:rgba(11,18,32,.45);border:1px solid rgba(71,85,105,.42)}.sidebar-module.current{border-color:rgba(96,165,250,.45);box-shadow:0 0 0 1px rgba(96,165,250,.18) inset}.sidebar-module-header{display:flex;justify-content:space-between;align-items:flex-start;gap:8px;margin-bottom:10px}.sidebar-module-header h4{margin:0;font-size:1rem;line-height:1.3}
.sidebar-lessons{list-style:none;padding:0;margin:0;display:grid;gap:6px}.sidebar-lessons a,.sidebar-lessons span{display:flex;justify-content:space-between;gap:10px;padding:10px 12px;border-radius:14px;color:#dbeafe;background:rgba(30,41,59,.55);border:1px solid rgba(51,65,85,.75)}.sidebar-lessons a.current{background:linear-gradient(90deg,rgba(37,99,235,.22),rgba(34,197,94,.16));border-color:rgba(96,165,250,.45);color:#fff}.sidebar-lessons span.locked{color:#fcd34d;background:rgba(38,30,8,.42);border-color:rgba(234,179,8,.22)}
.autoplay-box{display:grid;gap:10px}.toggle-row{display:flex;justify-content:space-between;align-items:center;gap:12px}.toggle{position:relative;width:54px;height:32px;display:inline-block}.toggle input{display:none}.toggle-slider{position:absolute;inset:0;background:#1f2937;border:1px solid rgba(148,163,184,.34);border-radius:999px;transition:.2s}.toggle-slider:before{content:"";position:absolute;width:24px;height:24px;left:3px;top:3px;background:#fff;border-radius:50%;transition:.2s}.toggle input:checked + .toggle-slider{background:rgba(34,197,94,.28);border-color:rgba(34,197,94,.45)}.toggle input:checked + .toggle-slider:before{transform:translateX(22px)}
.next-countdown{padding:12px 14px;border-radius:14px;background:rgba(34,197,94,.12);border:1px solid rgba(34,197,94,.24);display:none}.next-countdown.show{display:block}.next-countdown strong{display:block;margin-bottom:4px}.next-countdown small{display:block;color:#cbd5e1}
.student-course-card{display:flex;gap:18px;align-items:flex-start;flex-wrap:wrap}.student-course-card .course-content{flex:1 1 340px;min-width:280px}
.metrics-row{display:flex;gap:8px;flex-wrap:wrap;margin-top:10px}.metric-pill{padding:8px 12px;border-radius:999px;background:rgba(96,165,250,.14);border:1px solid rgba(96,165,250,.22);color:#dbeafe;font-size:.88rem;font-weight:700}
.lock-banner{padding:12px 14px;border-radius:16px;background:rgba(251,191,36,.12);border:1px solid rgba(251,191,36,.24);color:#fde68a}
.section-title{margin:0 0 8px 0}.section-copy{margin:0;color:#cbd5e1}
.install-body{padding:24px}
@media (max-width:1024px){.watch-layout{grid-template-columns:1fr}.sticky-stack{position:static}.lesson-progress-mini{text-align:left}.hero-cover{width:100%;max-width:420px;height:220px}}
@media (max-width:720px){.nav a{margin-left:8px;font-size:.92rem}.lesson-list li,.module-head,.watch-header,.student-course-card{flex-direction:column;align-items:flex-start;gap:10px}.split-actions{justify-content:flex-start}.course-cover{height:190px}.hero-cover{height:190px}}