body { font-family: Arial, sans-serif; margin: 20px; background: #f5f5f5; }
nav { background: #333; padding: 10px; margin-bottom: 20px; }
nav a { color: white; margin-right: 15px; text-decoration: none; }
nav a:hover { text-decoration: underline; }
.container { max-width: 900px; margin: auto; background: white; padding: 20px; border-radius: 5px; }
h1 { color: #333; }
table { width: 100%; border-collapse: collapse; margin-top: 10px; }
th, td { border: 1px solid #ddd; padding: 8px; text-align: left; }
th { background: #f2f2f2; }
.btn { display: inline-block; padding: 8px 15px; background: #007bff; color: white; text-decoration: none; border-radius: 3px; }
.btn-danger { background: #dc3545; }
.btn-success { background: #28a745; }
.alert { padding: 10px; margin-bottom: 15px; border-radius: 3px; }
.alert-error { background: #f8d7da; color: #721c24; }
.alert-success { background: #d4edda; color: #155724; }
.form-group { margin-bottom: 15px; }
label { display: block; margin-bottom: 5px; }
input, select { width: 100%; padding: 8px; box-sizing: border-box; }