* { margin:0; padding:0; box-sizing:border-box; }
body { font-family: 'Microsoft YaHei', sans-serif; background: #f5f7fa; color: #333; }
.container { max-width: 1000px; margin: 0 auto; padding: 0 20px; }

/* 登录页 */
.login-page { display: flex; justify-content: center; align-items: center; min-height: 100vh; background: linear-gradient(135deg, #1a2a4a, #0056b3); }
.login-container { background: #fff; padding: 40px; border-radius: 12px; box-shadow: 0 4px 20px rgba(0,0,0,0.2); width: 360px; }
.login-container h1 { text-align: center; margin-bottom: 20px; color: #1a2a4a; }
.login-container input { width: 100%; padding: 12px; margin-bottom: 15px; border: 1px solid #ddd; border-radius: 6px; }
.login-container button { width: 100%; padding: 12px; background: #0056b3; color: #fff; border: none; border-radius: 6px; font-size: 16px; cursor: pointer; }
.login-container .error { background: #f8d7da; color: #721c24; padding: 10px; border-radius: 6px; margin-bottom: 15px; }

/* 后台头部 */
.admin-header { background: #1a2a4a; color: #fff; padding: 15px 0; }
.admin-header .container { display: flex; justify-content: space-between; align-items: center; }
.admin-header a { color: #aac9ff; text-decoration: none; }
.admin-header a:hover { color: #fff; }

/* 后台主体 */
.admin-body { padding: 30px 0; }
.admin-table { width: 100%; background: #fff; border-collapse: collapse; box-shadow: 0 2px 8px rgba(0,0,0,0.05); }
.admin-table th, .admin-table td { padding: 12px 15px; border: 1px solid #e9ecef; text-align: left; }
.admin-table th { background: #f1f3f5; font-weight: 600; }
.admin-table a { margin-right: 8px; color: #0056b3; }
.admin-table a:hover { text-decoration: underline; }

/* 表单 */
.form-group { margin-bottom: 18px; }
.form-group label { display: block; font-weight: 600; margin-bottom: 5px; }
.form-group input, .form-group textarea { width: 100%; padding: 10px; border: 1px solid #ddd; border-radius: 6px; font-size: 14px; }
.form-group textarea { resize: vertical; }
button[type="submit"] { padding: 10px 30px; background: #0056b3; color: #fff; border: none; border-radius: 6px; font-size: 16px; cursor: pointer; }
button[type="submit"]:hover { background: #003d80; }

/* 仪表盘卡片 */
.dashboard-cards { display: flex; gap: 20px; margin-bottom: 30px; }
.card { background: #fff; padding: 25px; border-radius: 10px; box-shadow: 0 2px 10px rgba(0,0,0,0.05); flex: 1; text-align: center; }
.card h3 { font-size: 32px; margin-bottom: 5px; color: #1a2a4a; }
.card p { color: #666; }
.card a { display: inline-block; margin-top: 10px; padding: 6px 16px; background: #0056b3; color: #fff; border-radius: 20px; text-decoration: none; }
.card a:hover { background: #003d80; }

/* 消息 */
.error { background: #f8d7da; color: #721c24; padding: 12px; border-radius: 6px; margin-bottom: 15px; }
.success { background: #d4edda; color: #155724; padding: 12px; border-radius: 6px; margin-bottom: 15px; }