/* Base */
:root {
  --bg: #ffffff;
  --text: #1f2937;
  --muted: #6b7280;
  --primary: #2563eb;
  --surface: #f3f4f6;
  --border: #e5e7eb;
}

:root.dark {
  --bg: #0b1120;
  --text: #e5e7eb;
  --muted: #9ca3af;
  --primary: #60a5fa;
  --surface: #111827;
  --border: #1f2937;
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Ubuntu, Cantarell, Noto Sans, sans-serif;
  line-height: 1.6;
  background: var(--bg);
  color: var(--text);
}

.container { max-width: 960px; margin: 0 auto; padding: 0 16px; }

/* Header */
.site-header { position: sticky; top: 0; background: var(--surface); border-bottom: 1px solid var(--border); z-index: 10; }
.header-inner { display: flex; align-items: center; justify-content: space-between; padding: 12px 0; }
.brand { font-weight: 700; color: var(--text); text-decoration: none; }

.site-nav { position: relative; }
.menu { list-style: none; display: flex; gap: 12px; margin: 0; padding: 0; }
.menu a { text-decoration: none; color: var(--text); padding: 6px 10px; border-radius: 6px; }
.menu a:hover, .menu a:focus { background: var(--border); }

.nav-toggle { display: none; }
.theme-toggle { margin-left: 12px; }

/* Main */
.hero { padding: 24px 0; }
.demo-card { background: var(--surface); border: 1px solid var(--border); border-radius: 10px; padding: 16px; }

/* Buttons */
.button { background: var(--primary); color: white; border: none; padding: 8px 12px; border-radius: 8px; cursor: pointer; }
.button:hover { filter: brightness(0.95); }

/* Forms */
.form { display: grid; gap: 12px; max-width: 560px; }
.form-row { display: grid; gap: 6px; }
input, textarea { width: 100%; padding: 10px; border-radius: 8px; border: 1px solid var(--border); background: var(--bg); color: var(--text); }
.form-actions { display: flex; align-items: center; gap: 12px; }
.form-status { color: var(--muted); }

/* Footer */
.site-footer { border-top: 1px solid var(--border); margin-top: 48px; }
.site-footer .container { padding: 16px 0; color: var(--muted); }

/* Responsive */
@media (max-width: 640px) {
  .menu { display: none; position: absolute; right: 0; top: 44px; flex-direction: column; background: var(--surface); border: 1px solid var(--border); padding: 8px; min-width: 180px; border-radius: 8px; }
  .menu.open { display: flex; }
  .nav-toggle { display: inline-flex; align-items: center; justify-content: center; padding: 6px 8px; }
}