:root {
  --bg: #f8f9fa;
  --card-bg: #ffffff;
  --text: #1a1a1a;
  --text-secondary: #555;
  --accent: #0066cc;
  --border: #e0e0e0;
  --nav-bg: rgba(255, 255, 255, 0.95);
  --shadow: 0 2px 8px rgba(0,0,0,0.08);
  --radius: 8px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

[data-theme="dark"] {
  --bg: #121212;
  --card-bg: #1e1e1e;
  --text: #e0e0e0;
  --text-secondary: #aaa;
  --accent: #4dabf7;
  --border: #333;
  --nav-bg: rgba(18, 18, 18, 0.95);
  --shadow: 0 2px 8px rgba(0,0,0,0.3);
}

* { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: var(--font); background: var(--bg); color: var(--text); line-height: 1.5; transition: background 0.3s, color 0.3s; }

/* Sticky Nav */
.navbar {
  position: sticky; top: 0; z-index: 100;
  background: var(--nav-bg); backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
  padding: 0.75rem 1rem;
  display: flex; justify-content: space-between; align-items: center;
}
.nav-brand { font-weight: 700; font-size: 1.1rem; color: var(--text); text-decoration: none; }
.nav-controls { display: flex; gap: 0.5rem; align-items: center; }
.lang-btn, .theme-btn {
  background: transparent; border: 1px solid var(--border);
  color: var(--text); padding: 0.25rem 0.5rem; border-radius: 4px;
  cursor: pointer; font-size: 0.85rem; transition: all 0.2s;
}
.lang-btn.active { background: var(--accent); color: #fff; border-color: var(--accent); }
.theme-btn:hover, .lang-btn:hover { border-color: var(--accent); }

/* Grid */
.container { max-width: 1200px; margin: 0 auto; padding: 1.5rem 1rem; }
.museum-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); gap: 1.5rem; }

/* Card */
.card {
  background: var(--card-bg); border-radius: var(--radius);
  box-shadow: var(--shadow); overflow: hidden;
  display: flex; flex-direction: column;
  transition: transform 0.2s, box-shadow 0.2s;
}
.card:hover { transform: translateY(-2px); box-shadow: 0 4px 12px rgba(0,0,0,0.12); }
.card-header { padding: 1rem; border-bottom: 1px solid var(--border); display: flex; justify-content: space-between; align-items: flex-start; }
.card-title { font-size: 1.1rem; font-weight: 700; margin-bottom: 0.25rem; }
.card-meta { font-size: 0.8rem; color: var(--text-secondary); text-align: right; }
.card-body { padding: 1rem; flex: 1; }
.info-row { display: flex; gap: 0.5rem; margin-bottom: 0.5rem; font-size: 0.9rem; align-items: flex-start; }
.info-icon { flex-shrink: 0; width: 1.2em; text-align: center; color: var(--accent); }
.info-text a { color: var(--accent); text-decoration: none; }
.info-text a:hover { text-decoration: underline; }

/* Expandable Exhibitions */
.exhibitions-toggle {
  width: 100%; background: transparent; border: none; border-top: 1px solid var(--border);
  padding: 0.75rem 1rem; text-align: left; cursor: pointer;
  color: var(--accent); font-weight: 600; font-size: 0.9rem;
  display: flex; justify-content: space-between; align-items: center;
}
.exhibitions-toggle:hover { background: rgba(0,102,204,0.05); }
.exhibitions-content { display: none; padding: 0 1rem 1rem; }
.exhibitions-content.open { display: block; }
.exhibition-item { margin-bottom: 0.75rem; padding-bottom: 0.75rem; border-bottom: 1px dashed var(--border); }
.exhibition-item:last-child { border-bottom: none; margin-bottom: 0; padding-bottom: 0; }
.exh-title { font-weight: 600; font-size: 0.9rem; margin-bottom: 0.2rem; }
.exh-date { font-size: 0.8rem; color: var(--text-secondary); }
.countdown-bar { height: 4px; background: var(--border); border-radius: 2px; margin-top: 0.3rem; overflow: hidden; }
.countdown-fill { height: 100%; background: var(--accent); border-radius: 2px; transition: width 0.5s; }
.badge-upcoming { display: inline-block; background: #ff9800; color: #fff; font-size: 0.7rem; padding: 0.1rem 0.4rem; border-radius: 3px; margin-left: 0.3rem; vertical-align: middle; }

/* Footer */
.footer { text-align: center; padding: 2rem 1rem; font-size: 0.8rem; color: var(--text-secondary); border-top: 1px solid var(--border); margin-top: 2rem; }

/* Mobile */
@media (max-width: 600px) {
  .museum-grid { grid-template-columns: 1fr; }
  .navbar { padding: 0.5rem 0.75rem; }
  .nav-brand { font-size: 1rem; }
  .container { padding: 1rem 0.75rem; }
}