:root{
  --bg:#f5f7fb; --card:#ffffff; --ink:#1f2937; --muted:#6b7280;
  --line:#e5e7eb; --brand:#2563eb; --brand-d:#1d4ed8; --ok:#16a34a;
  --warn:#d97706; --danger:#dc2626; --shadow:0 8px 30px rgba(17,24,39,.08);
  --radius:16px;
}
*{box-sizing:border-box}
html,body{margin:0;padding:0}
body{font-family:"Segoe UI",system-ui,-apple-system,Roboto,Arial,sans-serif;
  background:var(--bg);color:var(--ink);line-height:1.5;-webkit-font-smoothing:antialiased}
a{color:var(--brand);text-decoration:none}
button{font:inherit;cursor:pointer}
img{max-width:100%}

/* ---------- buttons ---------- */
.btn{display:inline-flex;align-items:center;gap:8px;border:0;border-radius:10px;
  padding:10px 16px;background:var(--brand);color:#fff;font-weight:600;transition:.15s}
.btn:hover{background:var(--brand-d)}
.btn.ghost{background:#fff;color:var(--ink);border:1px solid var(--line)}
.btn.ok{background:var(--ok)} .btn.danger{background:var(--danger)}
.btn.sm{padding:6px 12px;font-size:13px;border-radius:8px}
.btn[disabled]{opacity:.5;cursor:not-allowed}

/* ---------- login ---------- */
.login-wrap{min-height:100vh;display:grid;place-items:center;position:relative;overflow:hidden;
  background:radial-gradient(1200px 600px at 80% -10%,#e8efff,transparent),var(--bg)}
.watermark{position:fixed;inset:0;display:grid;place-items:center;pointer-events:none;opacity:.05;z-index:0}
.watermark img{width:min(70vw,640px)}
.login-card{position:relative;z-index:1;width:min(94vw,420px);background:var(--card);
  border:1px solid var(--line);border-radius:20px;box-shadow:var(--shadow);padding:34px 30px}
.login-logo{display:flex;flex-direction:column;align-items:center;gap:10px;margin-bottom:18px;text-align:center}
.login-logo img{height:56px}
.login-logo h1{font-size:20px;margin:6px 0 0}
.login-logo p{margin:0;color:var(--muted);font-size:13px;font-weight:600;letter-spacing:.3px}
.field{margin:14px 0}
.field label{display:block;font-size:13px;font-weight:600;margin-bottom:6px;color:#374151}
.field input,.field select,.field textarea{width:100%;padding:11px 13px;border:1px solid var(--line);
  border-radius:10px;background:#fff;font-size:14px;outline:none;transition:.15s}
.field input:focus,.field select:focus,.field textarea:focus{border-color:var(--brand);
  box-shadow:0 0 0 3px rgba(37,99,235,.12)}
.err{color:var(--danger);font-size:13px;min-height:18px;margin-top:4px}
.err.blocked{background:#fef2f2;border:1px solid #fecaca;color:#b91c1c;padding:12px 14px;
  border-radius:10px;font-weight:600;line-height:1.45;text-align:left}

/* ---------- app shell ---------- */
.topbar{position:sticky;top:0;z-index:40;background:#fff;border-bottom:1px solid var(--line);
  display:flex;align-items:center;gap:14px;padding:10px 20px;box-shadow:0 2px 10px rgba(17,24,39,.03)}
.topbar .brand{display:flex;align-items:center;gap:10px;font-weight:700;min-width:0}
.topbar .brand img{height:34px;flex:none}
.topbar .brand>div{min-width:0;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;font-size:15px}
.topbar .brand small{display:block;color:var(--muted);font-weight:600;font-size:11px;overflow:hidden;text-overflow:ellipsis}
.spacer{flex:1}
.userchip{display:flex;align-items:center;gap:10px;font-weight:600;flex:none;min-width:0}
.topbar .btn.ghost.sm{flex:none}
.avatar{width:36px;height:36px;border-radius:50%;background:var(--brand);color:#fff;
  display:grid;place-items:center;font-weight:700;font-size:15px;flex:none}

/* live notice ticker */
.ticker{background:linear-gradient(90deg,#111827,#1f2937);color:#fff;overflow:hidden;white-space:nowrap;
  padding:8px 0;font-size:14px;position:relative}
.ticker .tag{position:relative;z-index:2;background:var(--brand);padding:8px 14px;margin-right:14px;
  font-weight:700;font-size:12px;white-space:nowrap;box-shadow:8px 0 12px -2px rgba(17,24,39,.9)}
.ticker .scroll{display:inline-block;padding-left:100%;animation:tick 28s linear infinite}
.ticker:hover .scroll{animation-play-state:paused}
@keyframes tick{to{transform:translateX(-100%)}}
.ticker .item{margin-right:60px}

.container{max-width:1180px;margin:0 auto;padding:22px 20px 60px}

/* hero */
.hero{background:#000;border-radius:var(--radius);overflow:hidden;box-shadow:var(--shadow);position:relative}
.hero video{width:100%;display:block;max-height:460px;background:#000}
.hero .hero-cap{position:absolute;left:20px;top:16px;color:#fff;text-shadow:0 2px 8px rgba(0,0,0,.7);pointer-events:none}
.hero .hero-cap h2{margin:0;font-size:22px}
.hero .hero-cap p{margin:2px 0 0;opacity:.85}

.section-title{display:flex;align-items:center;gap:10px;margin:28px 0 12px;font-size:18px}
.section-title .count{color:var(--muted);font-size:13px;font-weight:600}

/* progress */
.progress-card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);
  padding:18px 20px;box-shadow:var(--shadow);margin-top:18px}
.pbar{height:12px;background:#eef2f7;border-radius:20px;overflow:hidden;margin-top:10px}
.pbar>i{display:block;height:100%;background:linear-gradient(90deg,var(--brand),#22c55e);transition:width .5s}

/* grids */
.grid{display:grid;gap:16px}
.grid.cards{grid-template-columns:repeat(auto-fill,minmax(220px,1fr))}
.grid.folders{grid-template-columns:repeat(auto-fill,minmax(280px,1fr))}
.tile{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:18px;
  box-shadow:var(--shadow);transition:.18s;cursor:pointer}
.tile:hover{transform:translateY(-3px);box-shadow:0 14px 36px rgba(17,24,39,.12)}
.tile .ic{width:46px;height:46px;border-radius:12px;background:#eef2ff;display:grid;place-items:center;
  font-size:22px;margin-bottom:12px;overflow:hidden}
.tile .ic img{width:100%;height:100%;object-fit:cover}
.tile h3{margin:0 0 4px;font-size:16px}
.tile p{margin:0;color:var(--muted);font-size:13px}

.folder .vid-row{display:flex;align-items:center;gap:12px;padding:10px 0;border-top:1px solid var(--line)}
.folder .vid-row:first-of-type{border-top:0}
.folder .vid-row .t{flex:1;min-width:0;font-size:14px;line-height:1.3}
.folder .vid-row .btn.sm{flex:none;min-width:104px;justify-content:center}
.badge{flex:none;display:inline-flex;align-items:center;justify-content:center;gap:4px;
  font-size:11px;font-weight:700;padding:4px 10px;border-radius:20px;min-width:104px;white-space:nowrap}
.badge.done{background:#dcfce7;color:#166534}
.badge.lock{background:#f3f4f6;color:#6b7280}
.badge.play{background:#dbeafe;color:#1e40af}

/* modal */
.modal-bg{position:fixed;inset:0;background:rgba(15,23,42,.55);display:none;place-items:center;z-index:100;padding:16px}
.modal-bg.open{display:grid}
.modal{background:#fff;border-radius:18px;width:min(96vw,860px);max-height:92vh;overflow:auto;box-shadow:var(--shadow)}
.modal header{display:flex;align-items:center;padding:16px 20px;border-bottom:1px solid var(--line)}
.modal header h3{margin:0;font-size:17px}
.modal header .x{margin-left:auto;background:#f3f4f6;border:0;width:34px;height:34px;border-radius:50%;font-size:18px}
.modal .body{padding:20px}

/* video player */
.player-shell{background:#000;border-radius:14px;overflow:hidden}
.player-shell video{width:100%;display:block;max-height:60vh}
.player-controls{display:flex;align-items:center;gap:10px;padding:12px;background:#0b1220;color:#fff;flex-wrap:wrap}
.player-controls .time{font-variant-numeric:tabular-nums;font-size:13px;opacity:.8}

.empty{color:var(--muted);text-align:center;padding:40px;border:1px dashed var(--line);border-radius:var(--radius)}

/* ---------- inline icons ---------- */
.section-title svg{width:20px;height:20px;color:var(--brand);flex:none}
.ticker .tag svg{width:14px;height:14px;vertical-align:-2px;margin-right:6px}
.tile .ic svg{width:24px;height:24px;color:var(--brand)}
.badge svg{width:13px;height:13px;flex:none}
.btn svg{width:16px;height:16px;flex:none}
.tile .arrow{display:inline-flex;align-items:center;gap:4px;color:var(--brand);font-weight:600}
.tile .arrow svg{width:14px;height:14px}
.tile .fhead{display:flex;align-items:center;gap:8px}
.tile .fhead svg{width:18px;height:18px;color:var(--brand);flex:none}
.modal header h3 svg{width:18px;height:18px;vertical-align:-3px;margin-right:4px;color:var(--brand)}

@media(max-width:680px){
  .topbar{padding:9px 12px;gap:8px}
  .topbar .brand small{display:none}
  .topbar .brand>div{font-size:14px}
  /* hide username text, keep avatar (works for both span and bare text node) */
  .userchip{font-size:0;gap:0}
  .userchip .avatar{font-size:15px}
  .topbar .btn.ghost.sm{padding:7px 12px}
  .container{padding:16px 14px 50px}
  .hero video{max-height:240px}
  .hero .hero-cap{left:14px;top:12px}
  .hero .hero-cap h2{font-size:17px}
  .hero .hero-cap p{font-size:13px}
  .grid.cards,.grid.folders{grid-template-columns:1fr}
  .section-title{font-size:16px;margin:22px 0 10px}
  .progress-card{padding:16px}
}
@media(max-width:420px){
  .topbar .brand>div{display:none}
  .folder .vid-row .btn.sm,.badge{min-width:88px}
}