:root {
  --primary-color: #6366f1;
  --primary-hover: #4f46e5;
  --primary-light: rgba(99,102,241,0.1);
  --success-color: #10b981;
  --success-light: rgba(16,185,129,0.1);
  --warning-color: #f59e0b;
  --warning-light: rgba(245,158,11,0.1);
  --danger-color: #ef4444;
  --danger-light: rgba(239,68,68,0.1);
  --info-color: #3b82f6;
  --info-light: rgba(59,130,246,0.1);
  --dark-color: #1e293b;
  --light-color: #f1f5f9;
  --gray-color: #64748b;
  --border-color: #e2e8f0;
  --bg-color: #f8fafc;
  --sidebar-bg: #0f172a;
  --sidebar-hover: rgba(255,255,255,0.06);
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
  --shadow: 0 1px 3px rgba(0,0,0,0.1), 0 1px 2px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -1px rgba(0,0,0,0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.1), 0 4px 6px -2px rgba(0,0,0,0.05);
  --radius: 12px;
  --radius-sm: 8px;
  --radius-xs: 6px;
  --transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

* { margin: 0; padding: 0; box-sizing: border-box; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans SC", sans-serif;
  background: var(--bg-color);
  color: #334155;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

.admin-layout { display: flex; min-height: 100vh; }

/* ===== 侧边栏 ===== */
.sidebar {
  width: 260px;
  background: var(--sidebar-bg);
  color: #e2e8f0;
  display: flex;
  flex-direction: column;
  position: fixed;
  height: 100vh;
  overflow-y: auto;
  z-index: 200;
  transition: var(--transition);
}

.sidebar::-webkit-scrollbar { width: 4px; }
.sidebar::-webkit-scrollbar-thumb { background: rgba(255,255,255,0.1); border-radius: 4px; }

.logo {
  padding: 24px 20px;
  border-bottom: 1px solid rgba(255,255,255,0.06);
  display: flex;
  align-items: center;
  gap: 12px;
}

.logo-icon {
  width: 40px;
  height: 40px;
  background: linear-gradient(135deg, var(--primary-color), #8b5cf6);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
  flex-shrink: 0;
}

.logo-text h1 {
  font-size: 16px;
  font-weight: 700;
  color: #fff;
  line-height: 1.3;
}

.logo-sub {
  font-size: 11px;
  color: rgba(255,255,255,0.35);
  letter-spacing: 0.5px;
}

.menu { flex: 1; padding: 16px 12px; }

.menu-item {
  display: flex;
  align-items: center;
  padding: 11px 16px;
  color: rgba(255,255,255,0.5);
  text-decoration: none;
  border-radius: var(--radius-sm);
  transition: var(--transition);
  cursor: pointer;
  margin-bottom: 2px;
  font-size: 14px;
}

.menu-item:hover {
  background: var(--sidebar-hover);
  color: rgba(255,255,255,0.85);
}

.menu-item.active {
  background: linear-gradient(135deg, var(--primary-color), #8b5cf6);
  color: #fff;
  font-weight: 500;
  box-shadow: 0 4px 12px rgba(99,102,241,0.3);
}

.menu-item .icon {
  margin-right: 12px;
  font-size: 16px;
  width: 20px;
  text-align: center;
}

.user-info {
  padding: 16px 20px;
  border-top: 1px solid rgba(255,255,255,0.06);
  display: flex;
  align-items: center;
  gap: 12px;
}

.avatar {
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, #334155, #475569);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  flex-shrink: 0;
}

.user-detail { flex: 1; min-width: 0; }

.username {
  font-weight: 600;
  font-size: 13px;
  color: #e2e8f0;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.subscription-badge {
  display: inline-block;
  padding: 2px 8px;
  background: linear-gradient(135deg, var(--primary-color), #8b5cf6);
  border-radius: 4px;
  font-size: 11px;
  color: #fff;
  margin-top: 2px;
}

/* ===== 主内容区 ===== */
.main-content {
  flex: 1;
  margin-left: 260px;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.topbar {
  background: #fff;
  padding: 16px 32px;
  box-shadow: var(--shadow-sm);
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: sticky;
  top: 0;
  z-index: 100;
}

.topbar h2 {
  font-size: 20px;
  font-weight: 700;
  color: var(--dark-color);
}

.topbar-actions { display: flex; gap: 8px; }

.page-content {
  padding: 24px 32px;
  flex: 1;
}

/* ===== 按钮 ===== */
.btn {
  padding: 9px 18px;
  border: none;
  border-radius: var(--radius-xs);
  cursor: pointer;
  font-size: 13px;
  font-weight: 500;
  transition: var(--transition);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  white-space: nowrap;
}

.btn-primary { background: var(--primary-color); color: #fff; }
.btn-primary:hover { background: var(--primary-hover); box-shadow: 0 4px 12px rgba(99,102,241,0.3); }

.btn-success { background: var(--success-color); color: #fff; }
.btn-success:hover { background: #059669; }

.btn-danger { background: var(--danger-color); color: #fff; }
.btn-danger:hover { background: #dc2626; }

.btn-warning { background: var(--warning-color); color: #fff; }
.btn-warning:hover { background: #d97706; }

.btn-secondary { background: var(--gray-color); color: #fff; }
.btn-secondary:hover { background: #475569; }

.btn-icon {
  width: 36px;
  height: 36px;
  padding: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--light-color);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  color: var(--gray-color);
}

.btn-icon:hover { background: var(--border-color); color: var(--dark-color); }

.btn-logout:hover { background: var(--danger-light); border-color: var(--danger-color); color: var(--danger-color); }

.btn-sm { padding: 5px 12px; font-size: 12px; }

/* ===== 卡片 ===== */
.card {
  background: #fff;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 24px;
  margin-bottom: 20px;
  border: 1px solid var(--border-color);
}

.card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border-color);
}

.card-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--dark-color);
}

.card-body { color: #475569; }

/* ===== 统计卡片 ===== */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px;
  margin-bottom: 24px;
}

.stat-card {
  background: #fff;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 20px;
  display: flex;
  align-items: center;
  gap: 16px;
  border: 1px solid var(--border-color);
  transition: var(--transition);
}

.stat-card:hover { transform: translateY(-2px); box-shadow: var(--shadow-md); }

.stat-icon {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  flex-shrink: 0;
}

.stat-icon.primary { background: var(--primary-light); }
.stat-icon.success { background: var(--success-light); }
.stat-icon.warning { background: var(--warning-light); }
.stat-icon.danger { background: var(--danger-light); }

.stat-content { flex: 1; }

.stat-value {
  font-size: 24px;
  font-weight: 800;
  color: var(--dark-color);
  line-height: 1.2;
}

.stat-label {
  font-size: 13px;
  color: var(--gray-color);
  margin-top: 4px;
}

/* ===== 表格 ===== */
.table-container { overflow-x: auto; }

table { width: 100%; border-collapse: collapse; }

th, td {
  padding: 12px 16px;
  text-align: left;
  border-bottom: 1px solid var(--border-color);
}

th {
  background: var(--light-color);
  font-weight: 600;
  color: var(--gray-color);
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

td { font-size: 13px; color: #334155; }

tr:hover { background: rgba(99,102,241,0.02); }

.status-badge {
  padding: 4px 10px;
  border-radius: 20px;
  font-size: 12px;
  font-weight: 600;
  display: inline-block;
}

.status-active { background: var(--success-light); color: var(--success-color); }
.status-pending { background: var(--warning-light); color: var(--warning-color); }
.status-inactive { background: rgba(100,116,139,0.1); color: var(--gray-color); }
.status-danger { background: var(--danger-light); color: var(--danger-color); }

/* ===== 表单 ===== */
.form-group { margin-bottom: 20px; }

.form-label {
  display: block;
  margin-bottom: 6px;
  font-weight: 600;
  color: var(--dark-color);
  font-size: 13px;
}

.form-control {
  width: 100%;
  padding: 10px 14px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xs);
  font-size: 14px;
  transition: var(--transition);
  background: #fff;
  color: #334155;
}

.form-control:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px var(--primary-light);
}

.form-control:disabled { background: var(--light-color); cursor: not-allowed; }

textarea.form-control { min-height: 100px; resize: vertical; }

/* ===== 弹窗 ===== */
.modal {
  display: none;
  position: fixed;
  top: 0; left: 0;
  width: 100%; height: 100%;
  z-index: 1000;
  align-items: center;
  justify-content: center;
}

.modal.active { display: flex; }

.modal-overlay {
  position: absolute;
  top: 0; left: 0;
  width: 100%; height: 100%;
  background: rgba(15,23,42,0.6);
  backdrop-filter: blur(4px);
}

.modal-content {
  background: #fff;
  border-radius: var(--radius);
  width: 90%;
  max-width: 560px;
  max-height: 90vh;
  overflow-y: auto;
  position: relative;
  z-index: 1;
  box-shadow: var(--shadow-lg);
  animation: modalIn 0.25s ease;
}

@keyframes modalIn {
  from { opacity: 0; transform: scale(0.95) translateY(10px); }
  to { opacity: 1; transform: scale(1) translateY(0); }
}

.modal-header {
  padding: 20px 24px;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.modal-header h3 { font-size: 16px; font-weight: 700; color: var(--dark-color); }

.modal-body { padding: 24px; }
.modal-footer {
  padding: 16px 24px;
  border-top: 1px solid var(--border-color);
  display: flex;
  justify-content: flex-end;
  gap: 8px;
}

.btn-close {
  background: none;
  border: none;
  font-size: 20px;
  cursor: pointer;
  color: var(--gray-color);
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-xs);
  transition: var(--transition);
}

.btn-close:hover { background: var(--light-color); color: var(--dark-color); }

/* ===== Toast ===== */
.toast-container {
  position: fixed;
  top: 20px;
  right: 20px;
  z-index: 2000;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.toast {
  background: #fff;
  padding: 14px 20px;
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-lg);
  display: flex;
  align-items: center;
  gap: 10px;
  min-width: 280px;
  font-size: 13px;
  font-weight: 500;
  animation: toastIn 0.3s ease;
}

@keyframes toastIn {
  from { opacity: 0; transform: translateX(100%); }
  to { opacity: 1; transform: translateX(0); }
}

.toast.success { border-left: 4px solid var(--success-color); }
.toast.error { border-left: 4px solid var(--danger-color); }
.toast.warning { border-left: 4px solid var(--warning-color); }
.toast.info { border-left: 4px solid var(--info-color); }

/* ===== 加载动画 ===== */
.loading {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 60px 20px;
}

.spinner {
  width: 36px;
  height: 36px;
  border: 3px solid var(--border-color);
  border-top-color: var(--primary-color);
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
}

@keyframes spin { to { transform: rotate(360deg); } }

/* ===== 空状态 ===== */
.empty-state {
  text-align: center;
  padding: 48px 20px;
  color: var(--gray-color);
}

.empty-state-icon {
  font-size: 56px;
  margin-bottom: 16px;
  opacity: 0.4;
}

.empty-state-title {
  font-size: 16px;
  margin-bottom: 8px;
  color: var(--dark-color);
  font-weight: 600;
}

/* ===== 响应式 ===== */
@media (max-width: 768px) {
  .sidebar { width: 64px; }

  .logo-text, .menu-item span:not(.icon), .user-detail { display: none; }

  .logo { padding: 16px; justify-content: center; }
  .logo-icon { width: 36px; height: 36px; font-size: 18px; }

  .menu-item { justify-content: center; padding: 12px; }
  .menu-item .icon { margin-right: 0; font-size: 20px; }

  .user-info { justify-content: center; padding: 12px; }

  .main-content { margin-left: 64px; }
  .page-content { padding: 16px; }
  .stats-grid { grid-template-columns: 1fr; }
}