/* Sim Atlas hub — layout and components (uses tokens.css) */

body.hub {
  min-height: 100vh;
  background:
    radial-gradient(1200px 600px at 10% -10%, rgba(62, 230, 255, 0.10), transparent 60%),
    radial-gradient(900px 500px at 100% 0%, rgba(167, 139, 250, 0.12), transparent 60%),
    var(--bg);
  display: flex; flex-direction: column;
}
:root[data-theme="light"] body.hub {
  background:
    radial-gradient(1200px 600px at 10% -10%, rgba(62, 230, 255, 0.18), transparent 60%),
    radial-gradient(900px 500px at 100% 0%, rgba(167, 139, 250, 0.16), transparent 60%),
    var(--bg);
}
.container { width: 100%; max-width: var(--max-width); margin: 0 auto; padding: 0 var(--space-4); }
.skip-link { position: absolute; left: 8px; top: -48px; z-index: 100; padding: 8px 12px; background: var(--accent); color: #06101f; border-radius: 8px; font-weight: 600; }
.skip-link:focus { top: 8px; }
main { flex: 1; outline: none; }
h1, h2, h3 { color: var(--text-strong); margin: 0; line-height: 1.2; letter-spacing: -0.01em; }
h1 { font-size: clamp(28px, 4.5vw, var(--fs-3xl)); }
h2 { font-size: var(--fs-xl); }
h3 { font-size: var(--fs-lg); }
p { margin: 0; }
.muted { color: var(--muted); }
.row { display: flex; align-items: center; gap: var(--space-2); flex-wrap: wrap; }

/* ---------- header ---------- */
.site-header { position: sticky; top: 0; z-index: 50; background: var(--panel); border-bottom: 1px solid var(--panel-border); backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px); }
.site-header .container { display: flex; align-items: center; gap: var(--space-3); height: 60px; }
.brand { display: inline-flex; align-items: center; gap: 10px; text-decoration: none; color: var(--text-strong); font-weight: 700; font-size: var(--fs-lg); letter-spacing: -0.01em; }
.brand svg { width: 28px; height: 28px; }
.nav { display: flex; align-items: center; gap: var(--space-1); margin-left: var(--space-2); }
.nav a { color: var(--text); text-decoration: none; padding: 6px 10px; border-radius: 8px; font-size: var(--fs-sm); }
.nav a:hover, .nav a[aria-current="page"] { background: rgba(255,255,255,.08); color: var(--text-strong); }
.header-search { margin-left: auto; position: relative; flex: 0 1 320px; }
.header-search input, .hero-search input {
  width: 100%; background: rgba(255,255,255,.06); border: 1px solid var(--panel-border); border-radius: 999px; padding: 8px 14px 8px 36px; color: var(--text); font-size: var(--fs-sm);
}
.header-search svg, .hero-search svg { position: absolute; left: 12px; top: 50%; transform: translateY(-50%); width: 16px; height: 16px; opacity: .6; pointer-events: none; }
.header-search kbd { position: absolute; right: 10px; top: 50%; transform: translateY(-50%); font: 600 10px var(--font-mono); padding: 2px 6px; border: 1px solid var(--panel-border); border-radius: 5px; color: var(--muted); }
.header-tools { display: flex; align-items: center; gap: var(--space-2); }
.lang-select { background: rgba(255,255,255,.06); border: 1px solid var(--panel-border); border-radius: 999px; padding: 6px 10px; font-size: var(--fs-sm); cursor: pointer; }
.lang-select option { color: #000; }
.icon-btn { width: 36px; height: 36px; display: inline-grid; place-items: center; border-radius: 999px; border: 1px solid var(--panel-border); background: rgba(255,255,255,.06); cursor: pointer; }
.icon-btn:hover { background: rgba(255,255,255,.12); }

/* ---------- hero ---------- */
.hero { padding: clamp(40px, 8vw, 96px) 0 var(--space-6); text-align: center; }
.hero .eyebrow { display: inline-flex; gap: 8px; align-items: center; font-size: var(--fs-sm); color: var(--muted); margin-bottom: var(--space-4); }
.hero p.sub { max-width: 680px; margin: var(--space-4) auto 0; color: var(--muted); font-size: var(--fs-lg); }
.hero-search { position: relative; max-width: 620px; margin: var(--space-6) auto 0; }
.hero-search input { padding: 14px 18px 14px 44px; font-size: var(--fs-md); background: var(--panel-solid); box-shadow: var(--shadow-soft); }
.hero-search svg { left: 16px; width: 18px; height: 18px; }
.hero .stats { margin-top: var(--space-4); font-size: var(--fs-sm); color: var(--muted); }
.hero .actions { margin-top: var(--space-5); display: flex; justify-content: center; gap: var(--space-3); flex-wrap: wrap; }

/* ---------- sections ---------- */
.section { padding: var(--space-6) 0; }
.section-head { display: flex; align-items: end; justify-content: space-between; gap: var(--space-3); margin-bottom: var(--space-4); flex-wrap: wrap; }
.section-head p { color: var(--muted); margin-top: 4px; }
.grid { display: grid; gap: var(--space-4); grid-template-columns: repeat(auto-fill, minmax(270px, 1fr)); }
.grid.subjects { grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); }

/* ---------- subject tiles ---------- */
.subject-tile { --c: var(--accent); --c2: var(--accent-2); position: relative; overflow: hidden; display: flex; flex-direction: column; gap: var(--space-3); padding: var(--space-5); text-decoration: none; color: var(--text); background: var(--panel); border: 1px solid var(--panel-border); border-radius: var(--radius-lg); transition: transform .18s, border-color .18s, box-shadow .18s; min-height: 220px; }
.subject-tile::before { content: ""; position: absolute; inset: -40% auto auto -20%; width: 70%; aspect-ratio: 1; border-radius: 50%; background: radial-gradient(circle, color-mix(in srgb, var(--c) 35%, transparent), transparent 70%); pointer-events: none; }
.subject-tile:hover { transform: translateY(-3px); border-color: color-mix(in srgb, var(--c) 60%, var(--panel-border)); box-shadow: var(--shadow); }
.subject-tile .icon { font-size: 34px; line-height: 1; filter: drop-shadow(0 0 12px color-mix(in srgb, var(--c) 60%, transparent)); }
.subject-tile h3 { font-size: var(--fs-xl); color: var(--text-strong); }
.subject-tile .tagline { color: var(--muted); font-size: var(--fs-sm); flex: 1; }
.subject-tile .counts { display: flex; gap: 6px; flex-wrap: wrap; }
.subject-tile .featured { font-size: var(--fs-xs); color: var(--muted); }
.subject-tile .featured b { color: var(--c); font-weight: 600; }

/* ---------- topic cards ---------- */
.topic-card { --c: var(--accent); display: flex; flex-direction: column; text-decoration: none; color: var(--text); background: var(--panel); border: 1px solid var(--panel-border); border-radius: var(--radius-lg); overflow: hidden; transition: transform .18s, border-color .18s, box-shadow .18s; }
.topic-card:hover { transform: translateY(-3px); border-color: color-mix(in srgb, var(--c) 60%, var(--panel-border)); box-shadow: var(--shadow); }
.thumb { aspect-ratio: 16 / 9; background: linear-gradient(135deg, color-mix(in srgb, var(--c) 35%, #0b1020), color-mix(in srgb, var(--c2, var(--accent-2)) 25%, #0b1020)); display: grid; place-items: center; position: relative; overflow: hidden; }
.thumb img { width: 100%; height: 100%; object-fit: cover; display: block; }
.thumb .ph { font-size: 44px; filter: drop-shadow(0 0 18px color-mix(in srgb, var(--c) 70%, transparent)); opacity: .9; }
.thumb .ph-grid { position: absolute; inset: 0; background-image: linear-gradient(rgba(255,255,255,.05) 1px, transparent 1px), linear-gradient(90deg, rgba(255,255,255,.05) 1px, transparent 1px); background-size: 24px 24px; mask-image: radial-gradient(circle at center, #000 30%, transparent 80%); -webkit-mask-image: radial-gradient(circle at center, #000 30%, transparent 80%); }
.thumb .ribbon { position: absolute; top: 10px; left: 10px; display: flex; gap: 6px; }
.card-body { padding: var(--space-4); display: flex; flex-direction: column; gap: var(--space-2); flex: 1; }
.card-body h3 { font-size: var(--fs-md); }
.card-body p { color: var(--muted); font-size: var(--fs-sm); display: -webkit-box; -webkit-line-clamp: 3; -webkit-box-orient: vertical; overflow: hidden; }
.card-body .meta { margin-top: auto; display: flex; gap: 6px; flex-wrap: wrap; align-items: center; font-size: var(--fs-xs); color: var(--muted); padding-top: var(--space-2); }
.card-body .meta .subj { color: var(--c); font-weight: 600; }

/* chips */
.chip.status { font-weight: 600; }
.chip.status.published { color: #06101f; background: var(--success); border-color: transparent; }
.chip.status.draft { color: #06101f; background: var(--warning); border-color: transparent; }
.chip.status.planned { color: var(--muted); }
.chip.b3d { background: rgba(62,230,255,.14); color: var(--accent); border-color: rgba(62,230,255,.3); font-weight: 700; }
.chip.level { background: transparent; }
.chip.exp { background: rgba(251, 191, 36, .12); color: var(--warning); border-color: rgba(251,191,36,.3); }
.chip.idea { background: rgba(167, 139, 250, .14); color: var(--accent-2); border-color: rgba(167,139,250,.35); }
.chip .flag { font-size: 13px; }

/* ---------- subject page ---------- */
.subject-hero { --c: var(--accent); --c2: var(--accent-2); padding: var(--space-7) 0 var(--space-5); background: linear-gradient(180deg, color-mix(in srgb, var(--c) 14%, transparent), transparent); border-bottom: 1px solid var(--panel-border); }
.subject-hero .container { display: flex; gap: var(--space-5); align-items: center; flex-wrap: wrap; }
.subject-hero .big-icon { font-size: 64px; line-height: 1; filter: drop-shadow(0 0 24px color-mix(in srgb, var(--c) 70%, transparent)); }
.subject-hero p { color: var(--muted); max-width: 640px; margin-top: var(--space-2); font-size: var(--fs-lg); }
.subject-hero .counts { margin-top: var(--space-3); }
.crumbs { display: flex; gap: 6px; align-items: center; font-size: var(--fs-sm); color: var(--muted); flex-wrap: wrap; }
.crumbs a { color: var(--muted); text-decoration: none; }
.crumbs a:hover { color: var(--text-strong); }
.tabs { display: flex; gap: 6px; overflow-x: auto; padding: var(--space-4) 0; scrollbar-width: none; }
.tabs::-webkit-scrollbar { display: none; }
.tab { flex: none; display: inline-flex; flex-direction: column; align-items: flex-start; gap: 1px; padding: 8px 14px; border-radius: 12px; border: 1px solid var(--panel-border); background: rgba(255,255,255,.04); color: var(--text); text-decoration: none; min-width: 120px; }
.tab small { color: var(--muted); font-size: var(--fs-xs); }
.tab[aria-current="page"] { border-color: var(--c, var(--accent)); background: color-mix(in srgb, var(--c, var(--accent)) 18%, transparent); color: var(--text-strong); }
.tab:hover { background: rgba(255,255,255,.1); }
.empty { padding: var(--space-7) var(--space-4); text-align: center; color: var(--muted); border: 1px dashed var(--panel-border); border-radius: var(--radius-lg); }

/* ---------- topic page ---------- */
.topic-hero { --c: var(--accent); --c2: var(--accent-2); padding: var(--space-6) 0; }
.topic-hero .container { display: grid; grid-template-columns: 1.1fr .9fr; gap: var(--space-6); align-items: start; }
.topic-hero .thumb { border-radius: var(--radius-lg); border: 1px solid var(--panel-border); box-shadow: var(--shadow); }
.topic-hero h1 { margin: var(--space-3) 0; }
.topic-hero .lead { color: var(--text); font-size: var(--fs-lg); line-height: 1.6; }
.topic-hero .cta-row { margin-top: var(--space-5); display: flex; gap: var(--space-3); align-items: center; flex-wrap: wrap; }
.btn.big { padding: 12px 20px; font-size: var(--fs-md); border-radius: 12px; }
.facts { margin-top: var(--space-5); display: grid; grid-template-columns: repeat(auto-fit, minmax(170px, 1fr)); gap: var(--space-3); }
.fact { padding: var(--space-3) var(--space-4); border: 1px solid var(--panel-border); border-radius: var(--radius); background: var(--panel); }
.fact .k { font-size: var(--fs-xs); text-transform: uppercase; letter-spacing: .06em; color: var(--muted); margin-bottom: 6px; }
.fact .v { display: flex; gap: 6px; flex-wrap: wrap; align-items: center; font-size: var(--fs-sm); }
.note { font-size: var(--fs-sm); color: var(--muted); padding: 10px 14px; border-left: 3px solid var(--c, var(--accent)); background: rgba(255,255,255,.04); border-radius: 0 var(--radius-sm) var(--radius-sm) 0; }

/* ---------- about / prose ---------- */
.prose { max-width: 760px; }
.prose p { margin: var(--space-3) 0; color: var(--text); font-size: var(--fs-lg); line-height: 1.7; }
.prose ul { margin: var(--space-3) 0; padding-left: 1.2em; color: var(--text); }
.prose li { margin: 6px 0; }

/* ---------- footer ---------- */
.site-footer { border-top: 1px solid var(--panel-border); margin-top: var(--space-7); padding: var(--space-6) 0; color: var(--muted); font-size: var(--fs-sm); }
.site-footer .container { display: flex; justify-content: space-between; gap: var(--space-4); flex-wrap: wrap; align-items: center; }
.site-footer a { color: var(--muted); }
.site-footer a:hover { color: var(--text-strong); }
.site-footer .links { display: flex; gap: var(--space-4); flex-wrap: wrap; }

/* ---------- states ---------- */
.loading { padding: var(--space-8) 0; text-align: center; color: var(--muted); }
.spinner { width: 28px; height: 28px; border-radius: 50%; border: 3px solid var(--panel-border); border-top-color: var(--accent); animation: spin .8s linear infinite; margin: 0 auto var(--space-3); }
@keyframes spin { to { transform: rotate(360deg); } }
.error-box { margin: var(--space-6) auto; max-width: 640px; padding: var(--space-5); border: 1px solid rgba(248,113,113,.4); background: rgba(248,113,113,.08); border-radius: var(--radius-lg); color: var(--text); }
.fade-in { animation: fade .25s ease-out; }
@keyframes fade { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: none; } }

/* ---------- responsive ---------- */
@media (max-width: 900px) {
  .topic-hero .container { grid-template-columns: 1fr; }
  .topic-hero .thumb { order: -1; }
}
@media (max-width: 720px) {
  .nav { display: none; }
  .header-search { display: none; }
  .site-header .container { gap: var(--space-2); }
  .header-tools { margin-left: auto; }
  .subject-hero .big-icon { font-size: 48px; }
  .hero { padding-top: 40px; }
}