:root {
  --bg: #0f172a;
  --card: #ffffff;
  --border: #e2e8f0;
  --primary: #0f766e;
  --muted: #64748b;
  --danger: #b91c1c;
}
* { box-sizing: border-box; }
body { margin: 0; font-family: Arial, sans-serif; background: #f8fafc; color: #0f172a; }
header { background: var(--bg); color: #fff; padding: 16px 24px; }
nav a { color: #fff; text-decoration: none; margin-right: 14px; font-size: 14px; }
main { padding: 24px; }
.container { max-width: 1200px; margin: 0 auto; }
.card { background: var(--card); border: 1px solid var(--border); border-radius: 10px; padding: 18px; margin-bottom: 20px; }
.grid { display: grid; gap: 16px; grid-template-columns: repeat(auto-fit,minmax(220px,1fr)); }
.metric { font-size: 28px; font-weight: bold; }
.muted { color: var(--muted); }
.table { width: 100%; border-collapse: collapse; }
.table th, .table td { padding: 10px; border-bottom: 1px solid var(--border); text-align: left; font-size: 14px; vertical-align: top; }
.btn { background: var(--primary); color: white; border: none; padding: 10px 14px; border-radius: 8px; cursor: pointer; text-decoration: none; display: inline-block; }
.btn-secondary { background: #334155; }
.btn-danger { background: var(--danger); }
.btn-light { background: #cbd5e1; color: #0f172a; }
label { display: block; margin-bottom: 6px; font-weight: 600; }
input, select, textarea { width: 100%; padding: 10px; border: 1px solid var(--border); border-radius: 8px; margin-bottom: 12px; }
textarea { min-height: 120px; }
.flash-success, .flash-error { padding: 12px 14px; border-radius: 8px; margin-bottom: 16px; }
.flash-success { background: #dcfce7; color: #166534; }
.flash-error { background: #fee2e2; color: #991b1b; }
.actions form { display: inline-block; margin-right: 6px; }
code { background: #eef2ff; padding: 2px 6px; border-radius: 6px; }
.small { font-size: 12px; }