* { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif; background: #f5f7fa; color: #333; }
.app-container { display: flex; min-height: 100vh; }
.sidebar { width: 220px; background: #1e2a3a; color: #fff; padding: 20px 0; }
.sidebar .logo { font-size: 20px; font-weight: bold; text-align: center; margin-bottom: 30px; }
.sidebar nav a { display: block; padding: 15px 20px; color: #cbd5e1; text-decoration: none; }
.sidebar nav a:hover { background: #3b82f6; color: #fff; }
.main-content { flex: 1; padding: 30px; width: calc(100% - 220px); }
.main-content.login-mode { width: 100%; display: flex; justify-content: center; align-items: center; background: #f5f7fa; }
h1, h2, h3 { margin-bottom: 20px; }
.card { background: #fff; border-radius: 8px; box-shadow: 0 2px 4px rgba(0,0,0,0.05); padding: 20px; margin-bottom: 20px; }
.form-group { margin-bottom: 15px; }
.form-group label { display: block; margin-bottom: 5px; font-weight: bold; }
.form-group input, .form-group select, .form-group textarea { width: 100%; padding: 10px; border: 1px solid #ddd; border-radius: 4px; }
.btn { display: inline-block; padding: 10px 15px; border-radius: 4px; cursor: pointer; border: none; text-decoration: none; font-size: 14px; }
.btn-primary { background: #3b82f6; color: #fff; }
.btn-secondary { background: #e2e8f0; color: #333; }
.btn-danger { background: #ef4444; color: #fff; }
table { width: 100%; border-collapse: collapse; background: #fff; }
th, td { padding: 12px 15px; text-align: left; border-bottom: 1px solid #ddd; }
th { background: #f8fafc; }
tr:hover { background: #f1f5f9; }
.toast { position: fixed; top: 20px; right: 20px; padding: 15px 20px; background: #333; color: #fff; border-radius: 4px; display: none; z-index: 1000; }
.toast.success { background: #10b981; }
.toast.error { background: #ef4444; }
.modal-overlay { position: fixed; top: 0; left: 0; right: 0; bottom: 0; background: rgba(0,0,0,0.5); display: none; justify-content: center; align-items: center; z-index: 100; backdrop-filter: blur(2px); }
.modal-content { background: #fff; padding: 30px; border-radius: 8px; width: 400px; max-width: 90%; }
.grid-cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 20px; }