:root {
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --primary-glow: rgba(37, 99, 235, 0.18);
  --primary-light: #eff6ff;
  --bg-page: #f8fafc;
  --bg-card: rgba(255, 255, 255, 0.82);
  --border-color: #e2e8f0;
  --dark: #0f172a;
  --text-main: #334155;
  --text-muted: #64748b;
  --radius-sm: 12px;
  --radius-md: 20px;
  --radius-lg: 28px;
  --radius-full: 9999px;
  --shadow-sm: 0 2px 8px rgba(15, 23, 42, 0.06);
  --shadow-md: 0 12px 28px -6px rgba(15, 23, 42, 0.12);
  --font-fa: 'Vazirmatn', sans-serif;
}
[data-theme="dark"] {
  --primary: #3b82f6;
  --primary-hover: #60a5fa;
  --primary-glow: rgba(59, 130, 246, 0.28);
  --primary-light: rgba(59, 130, 246, 0.14);
  --bg-page: #090d16;
  --bg-card: rgba(15, 23, 42, 0.78);
  --border-color: rgba(255, 255, 255, 0.09);
  --dark: #f8fafc;
  --text-main: #cbd5e1;
  --text-muted: #94a3b8;
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 12px 28px -6px rgba(0, 0, 0, 0.6);
}
* { box-sizing: border-box; margin: 0; padding: 0; font-family: var(--font-fa); -webkit-tap-highlight-color: transparent; }
html { overflow-x: hidden; -webkit-text-size-adjust: 100%; text-size-adjust: 100%; scroll-behavior: smooth; }
body { background: var(--bg-page); color: var(--text-main); min-height: 100svh; line-height: 1.7; overflow-x: hidden; transition: background-color 0.3s ease, color 0.3s ease; }
body::before { content: ''; position: fixed; top: -20%; left: 50%; transform: translateX(-50%); width: min(720px, 100vw); height: 520px; background: radial-gradient(circle, var(--primary-glow) 0%, transparent 70%); filter: blur(80px); pointer-events: none; z-index: 0; }
.container { width: 100%; max-width: 1240px; margin: 0 auto; padding: 0 24px; position: relative; z-index: 1; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }
.skip-link { position: absolute; top: 0; right: 0; z-index: 2000; transform: translateY(-120%); display: inline-flex; align-items: center; min-height: 48px; padding: 0 20px; background: var(--primary); color: #fff; font-weight: 700; text-decoration: none; border-radius: 0 0 0 12px; transition: transform 0.2s ease; }
.skip-link:focus { transform: translateY(0); }
a:focus-visible, button:focus-visible, input:focus-visible, select:focus-visible { outline: 3px solid var(--primary); outline-offset: 2px; border-radius: 8px; }

/* nav */
.res-nav { position: sticky; top: 0; z-index: 100; backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px); background: color-mix(in srgb, var(--bg-page) 88%, transparent); border-bottom: 1px solid var(--border-color); }
.res-nav-inner { display: flex; align-items: center; justify-content: space-between; gap: 12px; height: 72px; }
.brand { font-weight: 900; font-size: 1.2rem; color: var(--dark); text-decoration: none; }
.brand span { color: var(--primary); }
.nav-links { display: flex; align-items: center; gap: 8px; }
.nav-link { color: var(--text-muted); text-decoration: none; font-size: 0.88rem; font-weight: 700; padding: 10px 14px; border-radius: var(--radius-full); min-height: 44px; display: inline-flex; align-items: center; }
.nav-link:hover { color: var(--dark); background: var(--primary-light); }
.theme-btn { min-width: 48px; min-height: 48px; border-radius: 50%; border: 1px solid var(--border-color); background: var(--bg-card); cursor: pointer; font-size: 1.1rem; display: inline-flex; align-items: center; justify-content: center; }

/* hero */
.hero { padding: 48px 0 8px; text-align: center; }
.hero-badge { display: inline-flex; align-items: center; gap: 8px; background: var(--bg-card); border: 1px solid var(--border-color); backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px); padding: 8px 18px; border-radius: var(--radius-full); font-size: 0.84rem; font-weight: 700; color: var(--text-muted); box-shadow: var(--shadow-sm); }
.hero-badge .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--primary); box-shadow: 0 0 0 4px var(--primary-glow); }
.hero h1 { font-size: clamp(1.7rem, 4.5vw, 2.6rem); font-weight: 900; color: var(--dark); line-height: 1.4; margin: 18px 0 10px; }
.hero h1 .grad { color: var(--primary); }
.hero p { color: var(--text-muted); max-width: 640px; margin: 0 auto; font-size: 0.98rem; }

/* toolbar */
.toolbar { margin: 28px 0 6px; background: var(--bg-card); border: 1px solid var(--border-color); backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px); border-radius: var(--radius-md); padding: 18px; box-shadow: var(--shadow-sm); display: flex; flex-direction: column; gap: 14px; }
.search-row { display: flex; gap: 10px; flex-wrap: wrap; }
.search-box { position: relative; flex: 1 1 260px; }
.search-box .s-icon { position: absolute; right: 14px; top: 50%; transform: translateY(-50%); color: var(--text-muted); }
.search-box input { width: 100%; min-height: 52px; padding: 12px 44px 12px 14px; border-radius: 14px; border: 1px solid var(--border-color); background: var(--bg-page); color: var(--dark); font-size: 0.92rem; font-family: inherit; }
.search-box input:focus { border-color: var(--primary); outline: none; box-shadow: 0 0 0 3px var(--primary-glow); }
.selects { display: flex; gap: 10px; flex-wrap: wrap; }
.selects select { min-height: 52px; padding: 10px 14px; border-radius: 14px; border: 1px solid var(--border-color); background: var(--bg-page); color: var(--dark); font-size: 0.88rem; font-family: inherit; min-width: 150px; }
.chips { display: flex; gap: 8px; flex-wrap: wrap; }
.chip { min-height: 44px; padding: 8px 18px; border-radius: var(--radius-full); border: 1px solid var(--border-color); background: transparent; color: var(--text-muted); font-weight: 800; font-size: 0.85rem; cursor: pointer; transition: all 0.18s ease; }
.chip:hover { border-color: var(--primary); color: var(--dark); }
.chip[aria-pressed="true"] { background: var(--primary); border-color: var(--primary); color: #fff; box-shadow: 0 6px 16px var(--primary-glow); }
.result-count { font-size: 0.82rem; color: var(--text-muted); font-weight: 700; }

/* grid + cards — fixed min-height prevents CLS */
.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(min(330px, 100%), 1fr)); gap: 18px; margin: 20px 0 60px; min-height: 420px; }
.card { background: var(--bg-card); border: 1px solid var(--border-color); backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px); border-radius: var(--radius-md); padding: 22px; box-shadow: var(--shadow-sm); display: flex; flex-direction: column; gap: 12px; min-height: 300px; transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease; content-visibility: auto; contain-intrinsic-size: auto 300px; }
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); border-color: var(--primary); }
.card-top { display: flex; gap: 8px; flex-wrap: wrap; align-items: center; min-height: 30px; }
.badge { display: inline-flex; align-items: center; gap: 6px; padding: 4px 12px; border-radius: var(--radius-full); font-size: 0.76rem; font-weight: 800; }
.badge-pdf { background: rgba(37, 99, 235, 0.12); color: #2563eb; border: 1px solid rgba(37, 99, 235, 0.3); }
[data-theme="dark"] .badge-pdf { background: rgba(59, 130, 246, 0.16); color: #60a5fa; }
.badge-video { background: rgba(139, 92, 246, 0.12); color: #7c3aed; border: 1px solid rgba(139, 92, 246, 0.3); }
[data-theme="dark"] .badge-video { background: rgba(139, 92, 246, 0.18); color: #a78bfa; }
.badge-level { background: var(--primary-light); color: var(--primary); border: 1px solid var(--border-color); }
.badge-cat { background: transparent; color: var(--text-muted); border: 1px solid var(--border-color); }
.card h3 { font-size: 1.05rem; font-weight: 800; color: var(--dark); line-height: 1.6; min-height: 3.2em; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.card .desc { font-size: 0.87rem; color: var(--text-muted); line-height: 1.8; min-height: 3.2em; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.card .meta { display: flex; gap: 14px; flex-wrap: wrap; font-size: 0.78rem; color: var(--text-muted); font-weight: 700; }
.card .actions { display: flex; gap: 8px; margin-top: auto; padding-top: 6px; flex-wrap: wrap; }
.btn { min-height: 48px; padding: 10px 18px; border-radius: 12px; font-size: 0.87rem; font-weight: 800; cursor: pointer; border: 1px solid transparent; text-decoration: none; display: inline-flex; align-items: center; justify-content: center; gap: 6px; transition: all 0.18s ease; font-family: inherit; }
.btn-primary { background: var(--primary); color: #fff; flex: 1 1 auto; }
.btn-primary:hover { background: var(--primary-hover); transform: translateY(-1px); }
.btn-outline { background: transparent; border-color: var(--border-color); color: var(--dark); flex: 1 1 auto; }
.btn-outline:hover { border-color: var(--primary); color: var(--primary); }
.btn-block { width: 100%; }

/* skeleton — same footprint as cards, zero CLS */
.skel { background: var(--bg-card); border: 1px solid var(--border-color); border-radius: var(--radius-md); padding: 22px; min-height: 300px; display: flex; flex-direction: column; gap: 12px; overflow: hidden; }
.skel-line { border-radius: 8px; background: linear-gradient(90deg, var(--border-color) 25%, var(--primary-light) 50%, var(--border-color) 75%); background-size: 200% 100%; animation: shimmer 1.4s infinite; }
@keyframes shimmer { from { background-position: 200% 0; } to { background-position: -200% 0; } }
.empty-state { text-align: center; padding: 60px 20px; color: var(--text-muted); grid-column: 1 / -1; }
.empty-state .big { font-size: 3rem; margin-bottom: 10px; }

/* modal */
.modal { position: fixed; inset: 0; z-index: 1000; background: rgba(2, 6, 23, 0.7); backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px); display: none; align-items: center; justify-content: center; padding: 20px; }
.modal.active { display: flex; }
.modal-card { background: var(--bg-page); border: 1px solid var(--border-color); border-radius: var(--radius-lg); width: 100%; max-width: 820px; max-height: 90svh; overflow: auto; box-shadow: var(--shadow-md); }
.modal-head { display: flex; align-items: center; justify-content: space-between; gap: 12px; padding: 18px 22px; border-bottom: 1px solid var(--border-color); position: sticky; top: 0; background: var(--bg-page); z-index: 2; }
.modal-head h2 { font-size: 1.02rem; font-weight: 800; color: var(--dark); }
.modal-close { min-width: 48px; min-height: 48px; border-radius: 12px; border: 1px solid var(--border-color); background: transparent; color: var(--text-muted); font-size: 1.2rem; cursor: pointer; }
.modal-close:hover { color: var(--dark); border-color: var(--primary); }
.video-wrap { position: relative; width: 100%; aspect-ratio: 16 / 9; background: #000; }
.video-wrap iframe { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; }
.modal-foot { padding: 16px 22px; display: flex; gap: 10px; flex-wrap: wrap; border-top: 1px solid var(--border-color); }

.footer { border-top: 1px solid var(--border-color); padding: 26px 0; text-align: center; color: var(--text-muted); font-size: 0.85rem; }
.footer a { color: var(--primary); text-decoration: none; font-weight: 700; }

@media (max-width: 640px) {
  .container { padding: 0 14px; }
  .hero { padding: 32px 0 4px; }
  .grid { grid-template-columns: 1fr; }
  .selects select { flex: 1 1 100%; }
  .nav-links .nav-link.hide-m { display: none; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.001ms !important; transition-duration: 0.001ms !important; }
  .card:hover, .btn-primary:hover { transform: none; }
  .skel-line { animation: none; }
}