:root {
  --bg: #f7f7f9;
  --surface: #ffffff;
  --border: #e2e5ea;
  --text: #1f2937;
  --muted: #6b7280;
  --primary: #0f766e;
}
* { box-sizing: border-box; }
body { margin: 0; font-family: Inter, Arial, sans-serif; background: var(--bg); color: var(--text); display: grid; grid-template-columns: 240px 1fr; min-height: 100vh; }
.sidebar { background: #111827; color: white; padding: 24px; }
.sidebar nav { display: flex; flex-direction: column; gap: 10px; margin-top: 20px; }
.sidebar a { color: #d1d5db; text-decoration: none; }
.sidebar a:hover { color: white; }
.content { padding: 32px; }
.card { background: var(--surface); border: 1px solid var(--border); border-radius: 12px; padding: 20px; margin-top: 16px; }
.grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 16px; }
input { width: 100%; padding: 10px 12px; margin: 6px 0 14px; border: 1px solid var(--border); border-radius: 8px; }
button { background: var(--primary); color: white; border: none; padding: 10px 14px; border-radius: 8px; cursor: pointer; }
@media (max-width: 900px) {
  body { grid-template-columns: 1fr; }
  .grid { grid-template-columns: 1fr 1fr; }
}