:root {
  --bg: #ffffff;
  --text: #111827;
  --muted: #6b7280;
  --brand: #4f46e5;
  --card: #f9fafb;
  --border: #e5e7eb;
  --radius: 16px;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, "Noto Sans", "Apple Color Emoji", "Segoe UI Emoji";
  background: var(--bg);
  color: var(--text);
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; border-radius: 12px; }

.site-header {
  display: grid; grid-template-columns: auto 1fr auto; align-items: center;
  gap: 16px; padding: 12px 16px; border-bottom: 1px solid var(--border); position: sticky; top: 0; background: var(--bg); z-index: 10;
}
.logo svg { height: 36px; }
.search { display: flex; gap: 8px; }
.search input { flex: 1; padding: 10px 14px; border-radius: 12px; border: 1px solid var(--border); font-size: 16px; }
.search button, .post-btn, button { padding: 10px 16px; border-radius: 12px; border: 1px solid var(--border); background: var(--card); cursor: pointer; font-weight: 600; }
.post-btn { background: #10b981; border-color: #10b981; color: white; }
.user-nav { display: flex; gap: 12px; align-items: center; justify-content: flex-end; }
.user-nav a.muted { color: var(--muted); }

.top-nav { display: flex; gap: 12px; padding: 8px 16px; overflow-x: auto; border-bottom: 1px solid var(--border); }
.top-nav a { padding: 8px 12px; border: 1px solid var(--border); border-radius: 999px; background: var(--card); white-space: nowrap; }

.container { max-width: 1100px; margin: 0 auto; padding: 16px; }
.hero { padding: 24px; border: 1px solid var(--border); background: var(--card); border-radius: var(--radius); text-align: center; }
.categories h2, .latest h2 { margin-top: 24px; }
.cat-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 16px; }
.cat-card { padding: 16px; border: 1px solid var(--border); border-radius: var(--radius); background: var(--bg); }
.cat-card h3 { margin: 0 0 8px 0; }
.cat-card ul { margin: 0; padding-left: 18px; color: var(--muted); }

.ad-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 16px; }
.ad-card { border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; background: var(--bg); position: relative; }
.ad-card .ad-meta { padding: 12px; }
.ad-card h3 { margin: 0 0 4px 0; font-size: 16px; }
.ad-card .price { font-weight: 700; }
.ad-card .muted { color: var(--muted); font-size: 12px; }

.ad-detail { display: grid; grid-template-columns: 1.2fr 1fr; gap: 24px; }
.ad-detail .gallery { display: grid; gap: 8px; align-content: start; }
.ad-info .price-lg { font-size: 28px; font-weight: 800; margin: 8px 0 12px; }
.ad-info .desc { white-space: pre-wrap; }
.ad-info-top { display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.fav-form button { border: 1px solid var(--border); background: var(--bg); border-radius: 999px; padding: 6px 12px; }

.pagination { display: flex; gap: 8px; margin: 24px 0; }
.pagination a { padding: 8px 12px; border: 1px solid var(--border); border-radius: 8px; }
.pagination a.active { background: var(--brand); color: white; border-color: var(--brand); }

.post-form { display: grid; gap: 12px; }
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }
.post-form input, .post-form select, .post-form textarea { width: 100%; padding: 10px 12px; border-radius: 10px; border: 1px solid var(--border); }
.thumbs { display: grid; grid-template-columns: repeat(auto-fit, minmax(160px, 1fr)); gap: 12px; }
.thumb { border: 1px solid var(--border); padding: 8px; border-radius: 12px; }

.card-actions { display: flex; gap: 12px; padding: 12px; border-top: 1px solid var(--border); }

.filters { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 12px; }
.filters input, .filters select { padding: 8px 10px; border-radius: 10px; border: 1px solid var(--border); }

.site-footer { border-top: 1px solid var(--border); padding: 16px; text-align: center; color: var(--muted); margin-top: 32px; }

@media (max-width: 900px) {
  .ad-detail { grid-template-columns: 1fr; }
  .grid-2, .grid-3 { grid-template-columns: 1fr; }
}