:root {
  --primary: #1e5bb5;
  --primary-dark: #164694;
  --primary-light: #e8f0fc;
  --accent: #00a8e6;
  --bg: #f5f7fa;
  --card: #ffffff;
  --text: #1f2937;
  --text-secondary: #6b7280;
  --border: #e5e7eb;
  --success: #10b981;
  --warning: #f59e0b;
  --danger: #ef4444;
  --info: #3b82f6;
  --sidebar-width: 260px;
  --sidebar-collapsed: 64px;
  --radius: 8px;
  --shadow: 0 2px 8px rgba(0,0,0,0.06);
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html, body { height: 100%; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif; color: var(--text); background: var(--bg); }

/* Login */
.login-page { background: linear-gradient(135deg, #1e5bb5 0%, #0d2b5e 100%); display: flex; align-items: center; justify-content: center; min-height: 100vh; }
.login-container { width: 420px; max-width: 92%; animation: fadeIn 0.5s ease; }
.login-brand { text-align: center; color: #fff; margin-bottom: 24px; }
.login-logo { width: 80px; height: 80px; border-radius: 50%; background: #fff; padding: 8px; margin-bottom: 12px; }
.login-brand h1 { font-size: 28px; letter-spacing: 2px; }
.login-brand p { opacity: 0.9; font-size: 16px; }
.login-box { background: #fff; border-radius: var(--radius); box-shadow: 0 12px 40px rgba(0,0,0,0.18); padding: 28px; }
.login-tabs { display: flex; border-bottom: 1px solid var(--border); margin-bottom: 20px; }
.login-tab { flex: 1; padding: 12px; border: none; background: none; cursor: pointer; font-size: 15px; color: var(--text-secondary); position: relative; }
.login-tab.active { color: var(--primary); font-weight: 600; }
.login-tab.active::after { content: ''; position: absolute; bottom: -1px; left: 20%; width: 60%; height: 2px; background: var(--primary); }
.login-form .form-group { margin-bottom: 16px; }
.form-group label { display: block; margin-bottom: 6px; font-size: 13px; color: var(--text-secondary); }
.form-group input, .form-group select, .form-group textarea { width: 100%; padding: 10px 12px; border: 1px solid var(--border); border-radius: var(--radius); font-size: 14px; transition: border 0.2s; }
.form-group input:focus, .form-group select:focus, .form-group textarea:focus { outline: none; border-color: var(--primary); }
.captcha-row { display: flex; gap: 10px; }
.captcha-row input { flex: 1; }
#captchaCanvas, #registerCaptchaCanvas, #bindCaptchaCanvas { border: 1px solid var(--border); border-radius: var(--radius); cursor: pointer; background: #f9fafb; }
.btn { display: inline-flex; align-items: center; justify-content: center; padding: 10px 18px; border-radius: var(--radius); border: none; font-size: 14px; cursor: pointer; transition: all 0.2s; }
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-dark); }
.btn-block { width: 100%; padding: 12px; font-size: 15px; }
.btn-ghost { background: transparent; color: var(--text-secondary); border: 1px solid var(--border); }
.btn-ghost:hover { background: var(--bg); }
.btn-sm { padding: 6px 12px; font-size: 13px; }
.btn-success { background: var(--success); color: #fff; }
.btn-warning { background: var(--warning); color: #fff; }
.btn-danger { background: var(--danger); color: #fff; }
.btn-info { background: var(--info); color: #fff; }
.login-links { display: flex; justify-content: space-between; margin-top: 14px; }
.login-links a { color: var(--primary); font-size: 13px; text-decoration: none; }
.login-links a:hover { text-decoration: underline; }
.login-agreement { text-align: center; font-size: 12px; color: var(--text-secondary); margin-top: 18px; }

/* Modal */
.modal { position: fixed; inset: 0; background: rgba(0,0,0,0.45); display: flex; align-items: center; justify-content: center; z-index: 1000; }
.modal.hidden { display: none; }
.modal-content { background: #fff; border-radius: var(--radius); width: 420px; max-width: 92%; max-height: 90vh; overflow: auto; }
.modal-header { display: flex; justify-content: space-between; align-items: center; padding: 16px 20px; border-bottom: 1px solid var(--border); }
.modal-header h3 { font-size: 16px; }
.modal-close { font-size: 22px; cursor: pointer; color: var(--text-secondary); }
.modal-body { padding: 20px; }
.text-muted { color: var(--text-secondary); font-size: 13px; margin-bottom: 12px; }

/* App layout */
.app-page { display: flex; }
.sidebar { width: var(--sidebar-width); height: 100vh; background: #0f2444; color: #fff; display: flex; flex-direction: column; position: fixed; left: 0; top: 0; transition: width 0.25s; z-index: 100; }
.sidebar-brand { display: flex; align-items: center; gap: 12px; padding: 16px; border-bottom: 1px solid rgba(255,255,255,0.08); }
.sidebar-brand img { width: 42px; height: 42px; border-radius: 50%; background: #fff; }
.brand-title { font-size: 16px; font-weight: 700; letter-spacing: 1px; }
.brand-subtitle { font-size: 11px; opacity: 0.7; }
.sidebar-nav { flex: 1; overflow-y: auto; padding: 10px 0; }
.nav-group { margin-bottom: 4px; }
.nav-title { display: flex; align-items: center; justify-content: space-between; padding: 10px 16px; font-size: 13px; color: rgba(255,255,255,0.65); cursor: pointer; }
.nav-title:hover { color: #fff; }
.nav-items { display: none; }
.nav-group.open > .nav-items { display: block; }
.nav-item { display: block; padding: 10px 16px 10px 32px; color: rgba(255,255,255,0.8); font-size: 13px; text-decoration: none; border-left: 3px solid transparent; }
.nav-item:hover, .nav-item.active { color: #fff; background: rgba(255,255,255,0.06); border-left-color: var(--accent); }
.sidebar-footer { padding: 12px 16px; border-top: 1px solid rgba(255,255,255,0.08); }
.user-info { display: flex; flex-direction: column; margin-bottom: 8px; }
.user-info span { font-weight: 600; }
.user-info small { opacity: 0.65; font-size: 11px; }
.main-wrapper { margin-left: var(--sidebar-width); flex: 1; min-height: 100vh; display: flex; flex-direction: column; transition: margin-left 0.25s; }
.topbar { height: 56px; background: #fff; border-bottom: 1px solid var(--border); display: flex; align-items: center; padding: 0 20px; gap: 16px; position: sticky; top: 0; z-index: 90; }
.menu-toggle { background: none; border: none; font-size: 20px; cursor: pointer; color: var(--text-secondary); }
.breadcrumb { flex: 1; font-size: 16px; font-weight: 600; }
.topbar-actions { color: var(--text-secondary); font-size: 13px; }
.main-content { flex: 1; padding: 20px; }

/* Dashboard */
.dashboard { animation: fadeIn 0.3s; }
.kpi-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 16px; margin-bottom: 20px; }
.kpi-card { background: var(--card); border-radius: var(--radius); padding: 18px; box-shadow: var(--shadow); }
.kpi-card h4 { font-size: 13px; color: var(--text-secondary); margin-bottom: 8px; font-weight: normal; }
.kpi-card .value { font-size: 26px; font-weight: 700; color: var(--primary); }
.kpi-card .sub { font-size: 12px; color: var(--text-secondary); margin-top: 6px; }
.card { background: var(--card); border-radius: var(--radius); box-shadow: var(--shadow); margin-bottom: 20px; }
.card-header { padding: 16px 20px; border-bottom: 1px solid var(--border); display: flex; justify-content: space-between; align-items: center; }
.card-header h3 { font-size: 15px; }
.card-body { padding: 20px; }
.dashboard-grid { display: grid; grid-template-columns: 2fr 1fr; gap: 20px; }

/* Table */
.table-toolbar { display: flex; gap: 10px; margin-bottom: 14px; flex-wrap: wrap; }
.table-toolbar input, .table-toolbar select { padding: 8px 12px; border: 1px solid var(--border); border-radius: var(--radius); font-size: 13px; }
.table { width: 100%; border-collapse: collapse; font-size: 13px; }
.table th, .table td { padding: 12px; text-align: left; border-bottom: 1px solid var(--border); }
.table th { background: #f9fafb; color: var(--text-secondary); font-weight: 600; }
.table tr:hover { background: #f9fafb; }
.table .actions { display: flex; gap: 6px; }
.badge { display: inline-block; padding: 3px 8px; border-radius: 12px; font-size: 12px; }
.badge-success { background: #d1fae5; color: #065f46; }
.badge-warning { background: #fef3c7; color: #92400e; }
.badge-danger { background: #fee2e2; color: #991b1b; }
.badge-info { background: #dbeafe; color: #1e40af; }
.badge-default { background: #f3f4f6; color: #4b5563; }

/* Pagination */
.pagination { display: flex; justify-content: flex-end; align-items: center; gap: 8px; margin-top: 14px; }
.pagination button { padding: 6px 12px; border: 1px solid var(--border); background: #fff; border-radius: var(--radius); cursor: pointer; font-size: 13px; }
.pagination button:disabled { opacity: 0.5; cursor: not-allowed; }
.pagination .page-info { font-size: 13px; color: var(--text-secondary); }

/* Form */
.page-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 20px; }
.page-header h2 { font-size: 18px; }
.form-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 16px; }
.form-actions { display: flex; gap: 10px; margin-top: 20px; }

/* Misc */
.hidden { display: none !important; }
.empty-state { text-align: center; padding: 40px; color: var(--text-secondary); }
.empty-state p { margin-top: 8px; }

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

@media (max-width: 768px) {
  .sidebar { width: var(--sidebar-collapsed); }
  .sidebar-brand .brand-title, .sidebar-brand .brand-subtitle, .nav-title span, .nav-item span, .user-info { display: none; }
  .main-wrapper { margin-left: var(--sidebar-collapsed); }
  .dashboard-grid { grid-template-columns: 1fr; }
}