:root {
  --primary: #2563eb;
  --bg: #f8fafc;
  --card: #fff;
  --border: #e2e8f0;
  --text: #1e293b;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: system-ui, sans-serif; background: var(--bg); color: var(--text); }
nav { background: var(--card); border-bottom: 1px solid var(--border); padding: 0.8rem 1.5rem; display: flex; align-items: center; flex-wrap: wrap; gap: 0.5rem; }
nav h2 { margin-right: auto; }
button { padding: 0.4rem 0.8rem; border: 1px solid var(--border); border-radius: 4px; background: var(--card); cursor: pointer; }
button:hover { background: var(--primary); color: #fff; border-color: var(--primary); }
main { padding: 1.5rem; max-width: 1200px; margin: 0 auto; }
.card { background: var(--card); border: 1px solid var(--border); border-radius: 8px; padding: 1.5rem; margin-bottom: 1rem; }
table { width: 100%; border-collapse: collapse; }
th, td { padding: 0.5rem; text-align: left; border-bottom: 1px solid var(--border); }
.form-group { margin-bottom: 1rem; }
input, textarea, select { width: 100%; padding: 0.5rem; border: 1px solid var(--border); border-radius: 4px; font-size: 0.95rem; }
.login-page { display: flex; justify-content: center; align-items: center; height: 100vh; }
.login-box { width: 320px; padding: 2rem; background: var(--card); border-radius: 8px; box-shadow: 0 4px 6px rgba(0,0,0,0.1); }
.login-box h1 { text-align: center; margin-bottom: 1.5rem; }
#logoutBtn { background: #ef4444; color: #fff; border: none; }