/* Minimal, fast, accessible styles */
:root {
  --bg: #ffffff;
  --text: #1a1a1a;
  --muted: #6b7280;
  --card: #f8fafc;
  --accent: #00539b; /* PSU blue-ish */
  --ring: rgba(0, 83, 155, 0.25);
}

* { box-sizing: border-box; }
html { font-family: 'Inter', system-ui, -apple-system, Segoe UI, Roboto, sans-serif; }
body { margin: 0; background: var(--bg); color: var(--text); line-height: 1.6; }

.container { width: min(100%, 960px); margin: 0 auto; padding: 0 20px; }

.site-header { position: sticky; top: 0; background: rgba(255,255,255,0.9); backdrop-filter: blur(6px); border-bottom: 1px solid #eee; }
.header-inner { display: flex; align-items: center; justify-content: space-between; padding: 18px 0; }
.identity h1 { margin: 0; font-size: 1.6rem; letter-spacing: 0.2px; }
.subtitle { margin: 2px 0 0; color: var(--muted); font-weight: 400; font-size: 0.95rem; }

.btn { display: inline-block; padding: 8px 14px; color: white; background: var(--accent); border-radius: 8px; text-decoration: none; font-weight: 600; }
.btn:focus-visible { outline: 3px solid var(--ring); outline-offset: 2px; }

main { padding: 28px 0 48px; }
.card { background: var(--card); border: 1px solid #e5e7eb; border-radius: 4px; padding: 20px; margin-bottom: 20px; }
h2 { margin: 0 0 12px; font-size: 1.25rem; }
h3 { margin: 8px 0 6px; font-size: 1.05rem; }
.muted { color: var(--muted); font-size: 0.95rem; }

.gallery { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 16px; }
.gallery figure { margin: 0; background: #fff; border: 1px solid #eef2f7; border-radius: 12px; overflow: hidden; }
.gallery a { display: block; }
.gallery a:hover { transform: translateY(-2px); transition: transform 150ms ease; }
.gallery img { width: 100%; height: 200px; object-fit: cover; display: block; }
.gallery figcaption { padding: 12px 14px; font-size: 0.92rem; color: var(--muted); line-height: 1.4; }

.teaching-content { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.teaching-content h3 { margin: 0 0 8px; font-size: 1.05rem; }
.teaching-content ul { margin: 0; padding-left: 18px; }
.teaching-content li { margin: 4px 0; }

@media (max-width: 640px) {
  .teaching-content { grid-template-columns: 1fr; gap: 16px; }
}

.site-footer { border-top: 1px solid #eee; padding: 24px 0; background: #fff; }
.site-footer small { color: var(--muted); }

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b0e14;
    --text: #e5e7eb;
    --muted: #9aa4b2;
    --card: #111827;
    --accent: #3b82f6;
    --ring: rgba(59, 130, 246, 0.35);
  }
  .site-header { background: rgba(11,14,20,0.7); border-color: #111; }
  .card, .gallery figure { border-color: #1f2937; }
  .gallery img { filter: brightness(0.95) contrast(1.05); }
}