/* AI University (umbrella) — house tokens, indigo accent. */
:root {
  --paper: #f8fafc; --panel: #ffffff; --panel-alt: #f1f5f9;
  --ink: #1e293b; --ink-strong: #0f172a; --muted: #64748b;
  --line: #e2e8f0; --line-strong: #cbd5e1;
  --accent: #4f46e5; --accent-hover: #4338ca; --accent-soft: #eef2ff;
  --radius-sm: 0.5rem; --radius: 0.75rem; --radius-lg: 1rem;
  --shadow: 0 1px 3px rgba(15,23,42,0.08), 0 1px 2px -1px rgba(15,23,42,0.06);
  --shadow-lg: 0 10px 25px -8px rgba(15,23,42,0.15), 0 4px 10px -4px rgba(15,23,42,0.08);
  --font-body: 'Manrope', ui-sans-serif, system-ui, sans-serif;
  --font-display: 'Fraunces', ui-serif, Georgia, serif;
  --font-mono: ui-monospace, 'SF Mono', Menlo, monospace;
  font-size: 16px;
}
:root[data-theme="dark"] {
  --paper: #0f172a; --panel: #1e293b; --panel-alt: #0f172a;
  --ink: #f1f5f9; --ink-strong: #ffffff; --muted: #94a3b8;
  --line: #334155; --line-strong: #475569;
  --accent: #a5b4fc; --accent-hover: #c7d2fe; --accent-soft: #1e1b4b;
}
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body { font-family: var(--font-body); line-height: 1.6; color: var(--ink); background: var(--paper); -webkit-font-smoothing: antialiased; }
a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-hover); }
h1, h2, h3 { font-family: var(--font-display); color: var(--ink-strong); line-height: 1.12; letter-spacing: -0.02em; }
.container { max-width: 1080px; margin: 0 auto; padding: 0 1.25rem; }

.nav { position: sticky; top: 0; z-index: 50; background: color-mix(in srgb, var(--paper) 85%, transparent); backdrop-filter: blur(12px); border-bottom: 1px solid var(--line); }
.nav-inner { display: flex; align-items: center; gap: 1.5rem; height: 64px; }
.brand { display: flex; align-items: center; gap: 0.6rem; }
.brand-mark { width: 40px; height: 40px; border-radius: 10px; flex-shrink: 0; }
.brand-name { font-family: var(--font-display); font-weight: 800; font-size: 1.15rem; color: var(--ink-strong); line-height: 1; }
.brand-tag { font-size: 0.72rem; color: var(--muted); font-weight: 600; }
.controls { margin-left: auto; }
.icon-btn { width: 36px; height: 36px; display: grid; place-items: center; border: 1px solid var(--line); border-radius: var(--radius-sm); background: var(--panel); color: var(--ink); cursor: pointer; }
.icon-btn:hover { border-color: var(--line-strong); }

.btn { display: inline-flex; align-items: center; justify-content: center; gap: 0.5rem; padding: 0.7rem 1.3rem; border-radius: var(--radius); font-weight: 700; font-size: 0.95rem; background: var(--accent); color: #fff; border: 1px solid transparent; cursor: pointer; font-family: var(--font-body); transition: transform .15s, background .15s; }
.btn:hover { background: var(--accent-hover); color: #fff; transform: translateY(-1px); }
.btn-lg { padding: 0.9rem 1.7rem; font-size: 1.05rem; }
.btn-ghost { background: transparent; color: var(--ink-strong); border-color: var(--line-strong); }
.btn-ghost:hover { background: var(--panel-alt); color: var(--ink-strong); }

.pill { display: inline-block; padding: 0.35rem 0.85rem; border-radius: 999px; background: var(--accent-soft); color: var(--accent-hover); font-weight: 700; font-size: 0.8rem; }
.tag { display: inline-block; font-size: 0.72rem; font-weight: 700; color: var(--muted); background: var(--panel-alt); border: 1px solid var(--line); padding: 0.2rem 0.55rem; border-radius: var(--radius-sm); }

.hero { padding: 4.5rem 0 3rem; }
.hero h1 { font-size: clamp(2.2rem, 5vw, 3.6rem); font-weight: 800; max-width: 16ch; }
.hero p.lead { font-size: 1.2rem; color: var(--muted); max-width: 56ch; margin: 1.1rem 0 1.8rem; }
.hero-cta { display: flex; gap: 0.8rem; flex-wrap: wrap; }

section { padding: 3rem 0; }
.section-head { margin-bottom: 1.8rem; }
.section-head h2 { font-size: clamp(1.6rem, 3vw, 2.2rem); font-weight: 700; }
.section-head p { color: var(--muted); margin-top: 0.5rem; }
.grid { display: grid; gap: 1.1rem; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); }
.card { background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius-lg); padding: 1.4rem; box-shadow: var(--shadow); display: flex; flex-direction: column; gap: 0.7rem; align-items: flex-start; }
.card h3 { font-size: 1.25rem; }
.card p { color: var(--muted); font-size: 0.95rem; }
.card.live { border-color: var(--accent); }
.card.soon { opacity: 0.92; }

footer { border-top: 1px solid var(--line); padding: 2.5rem 0; color: var(--muted); font-size: 0.88rem; margin-top: 2rem; }
footer .container { display: flex; flex-wrap: wrap; gap: 1rem; justify-content: space-between; }
.muted { color: var(--muted); }