:root {
  --bg: #0f1419;
  --surface: #1a222d;
  --text: #e7ecf2;
  --muted: #8b98a8;
  --accent: #6366f1;
  --accent-light: rgba(99, 102, 241, 0.15);
  --border: #2a3544;
  --danger: #f87171;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; background: var(--bg); color: var(--text); min-height: 100vh; }
.hidden { display: none !important; }
a { color: var(--accent); text-decoration: none; }

.nav {
  display: flex; align-items: center; justify-content: space-between;
  padding: 14px 28px; background: var(--surface); border-bottom: 1px solid var(--border);
}
.logo { display: flex; align-items: center; gap: 8px; font-weight: 700; font-size: 1.1rem; cursor: pointer; }
.logo-icon { width: 28px; height: 28px; background: var(--accent); border-radius: 6px; color: #fff; display: flex; align-items: center; justify-content: center; font-size: 12px; }
.nav-links { display: flex; gap: 10px; }

.btn {
  padding: 9px 18px; border-radius: 8px; font-size: 0.9rem; font-weight: 500; cursor: pointer; border: 1px solid var(--border);
  background: var(--surface); color: var(--text);
}
.btn-primary { background: var(--accent); color: #fff; border-color: var(--accent); }

.layout { display: flex; min-height: calc(100vh - 57px); }
.sidebar {
  width: 220px; background: var(--surface); border-right: 1px solid var(--border); padding: 20px 0; flex-shrink: 0;
}
.sidebar a {
  display: block; padding: 10px 24px; color: var(--muted); font-size: 0.9rem; cursor: pointer;
}
.sidebar a:hover, .sidebar a.active { color: var(--accent); background: var(--accent-light); }

.main { flex: 1; padding: 28px 32px; }
.main h2 { font-size: 1.3rem; margin-bottom: 4px; }
.main .sub { color: var(--muted); font-size: 0.85rem; margin-bottom: 24px; }

.video-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(160px, 1fr)); gap: 16px; margin-top: 20px; }
.video-card {
  background: var(--surface); border: 1px solid var(--border); border-radius: 10px; padding: 16px;
  text-align: center; cursor: pointer; transition: box-shadow 0.15s;
}
.video-card:hover { box-shadow: 0 4px 16px rgba(0,0,0,0.25); }
.video-card .thumb { font-size: 2rem; margin-bottom: 10px; }
.video-card .name { font-size: 0.85rem; font-weight: 500; }
.video-card .date { font-size: 0.75rem; color: var(--muted); margin-top: 4px; }

.sync-bar {
  display: flex; align-items: center; gap: 12px; padding: 12px 16px; background: var(--accent-light);
  border-radius: 8px; font-size: 0.85rem; color: var(--accent); margin-bottom: 20px;
}
.sync-bar .dot { width: 8px; height: 8px; background: var(--accent); border-radius: 50%; animation: pulse 1.5s infinite; }
@keyframes pulse { 0%,100% { opacity: 1; } 50% { opacity: 0.4; } }

.upload-zone {
  border: 2px dashed var(--border); border-radius: 10px; padding: 36px; text-align: center; cursor: pointer; margin-top: 16px;
}
.upload-zone:hover { border-color: var(--accent); }
.progress-wrap { margin-top: 16px; background: var(--border); border-radius: 8px; overflow: hidden; height: 8px; }
.progress-bar { height: 100%; width: 0; background: var(--accent); transition: width 0.15s; }

.page-narrow { max-width: 420px; margin: 0 auto; padding: 64px 24px; }
.card { background: var(--surface); border: 1px solid var(--border); border-radius: 12px; padding: 32px; }
.card h2 { margin-bottom: 8px; }
.form-group { margin-bottom: 14px; }
.form-group label { display: block; font-size: 0.85rem; margin-bottom: 4px; color: var(--muted); }
.form-group input {
  width: 100%; padding: 11px 14px; border: 1px solid var(--border); border-radius: 8px; font-size: 0.95rem;
  background: var(--bg); color: var(--text);
}
.form-group input:focus { outline: none; border-color: var(--accent); }

.alert { padding: 11px 14px; border-radius: 8px; font-size: 0.88rem; margin-bottom: 14px; }
.alert-error { background: rgba(248, 113, 113, 0.12); color: var(--danger); border: 1px solid rgba(248, 113, 113, 0.35); }

.hero { text-align: center; padding: 72px 24px; max-width: 640px; margin: 0 auto; }
.hero h1 { font-size: 2.2rem; margin-bottom: 12px; letter-spacing: -0.02em; }
.hero p { color: var(--muted); line-height: 1.6; margin-bottom: 28px; }

footer { text-align: center; padding: 24px; color: var(--muted); font-size: 0.8rem; border-top: 1px solid var(--border); margin-top: 40px; }

@media (max-width: 640px) {
  .layout { flex-direction: column; }
  .sidebar { width: 100%; display: flex; overflow-x: auto; padding: 0; }
  .sidebar a { white-space: nowrap; padding: 12px 16px; }
}