:root {
  --primary: #1677ff;
  --primary-dark: #0958d9;
  --primary-light: #e6f4ff;
  --primary-gradient: linear-gradient(135deg, #1677ff 0%, #4096ff 100%);
  --bg-page: #f7f8fc;
  --bg-card: #ffffff;
  --text: #1f1f1f;
  --text-secondary: #8c8c8c;
  --border: #f0f0f0;
  --shadow: 0 4px 24px rgba(22, 119, 255, 0.06);
  --shadow-lg: 0 12px 40px rgba(22, 119, 255, 0.1);
  --radius: 16px;
  --radius-lg: 20px;
  --sidebar-w: 240px;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  font-size: 14px;
  color: var(--text);
  background: var(--bg-page);
  line-height: 1.6;
}

a { color: var(--primary); text-decoration: none; }
a:hover { color: var(--primary-dark); }

/* Login */
.login-page {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(160deg, #e6f4ff 0%, #f7f8fc 45%, #ffffff 100%);
  padding: 24px;
}
.login-card {
  width: 100%;
  max-width: 420px;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  padding: 48px 40px;
  border: 1px solid rgba(255, 255, 255, 0.8);
}
.login-logo {
  text-align: center;
  margin-bottom: 36px;
}
.login-logo .logo-icon {
  width: 56px;
  height: 56px;
  margin: 0 auto 16px;
  background: var(--primary-gradient);
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 28px;
  color: #fff;
}
.login-logo h1 {
  font-size: 22px;
  font-weight: 700;
  color: var(--text);
}
.login-logo p {
  font-size: 13px;
  color: var(--text-secondary);
  margin-top: 6px;
  font-weight: 400;
}

/* Layout */
.admin-shell { display: flex; min-height: 100vh; }
.sidebar {
  width: var(--sidebar-w);
  background: var(--bg-card);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  position: fixed;
  top: 0; left: 0; bottom: 0;
  z-index: 100;
  box-shadow: 2px 0 16px rgba(0, 0, 0, 0.03);
}
.sidebar-brand {
  padding: 24px 20px;
  border-bottom: 1px solid var(--border);
}
.sidebar-brand h2 {
  font-size: 16px;
  font-weight: 700;
  color: var(--primary);
}
.sidebar-brand span {
  font-size: 12px;
  color: var(--text-secondary);
  font-weight: 400;
}
.sidebar-nav { flex: 1; padding: 16px 12px; overflow-y: auto; }
.nav-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 16px;
  border-radius: 12px;
  color: var(--text-secondary);
  font-weight: 500;
  margin-bottom: 4px;
  transition: all 0.2s;
}
.nav-item:hover { background: var(--primary-light); color: var(--primary); }
.nav-item.active {
  background: var(--primary-gradient);
  color: #fff;
  box-shadow: 0 4px 12px rgba(22, 119, 255, 0.25);
}
.nav-item .icon { font-size: 18px; width: 24px; text-align: center; }
.sidebar-footer {
  padding: 16px;
  border-top: 1px solid var(--border);
}
.sidebar-footer .user {
  font-size: 13px;
  color: var(--text-secondary);
  margin-bottom: 8px;
}
.sidebar-footer .user strong { color: var(--text); display: block; font-weight: 600; }

.main-wrap {
  flex: 1;
  margin-left: var(--sidebar-w);
  min-height: 100vh;
  background: linear-gradient(180deg, #f7f8fc 0%, #ffffff 40%);
}
.topbar {
  height: 64px;
  padding: 0 32px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 50;
}
.topbar h1 { font-size: 18px; font-weight: 700; }
.content { padding: 28px 32px 48px; }

/* Cards & stats */
.stat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 20px;
  margin-bottom: 28px;
}
.stat-card {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: var(--shadow);
  border: 1px solid rgba(255, 255, 255, 0.9);
  transition: transform 0.2s, box-shadow 0.2s;
}
.stat-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}
.stat-card .label {
  font-size: 13px;
  color: var(--text-secondary);
  font-weight: 400;
}
.stat-card .value {
  font-size: 32px;
  font-weight: 700;
  color: var(--text);
  margin-top: 8px;
  line-height: 1.2;
}
.stat-card .value.primary { color: var(--primary); }

.card {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
  margin-bottom: 24px;
  overflow: hidden;
}
.card-header {
  padding: 20px 24px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}
.card-header h3 { font-size: 16px; font-weight: 700; }
.card-body { padding: 24px; }

/* Forms */
.form-group { margin-bottom: 20px; }
.form-group label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 8px;
}
.form-control {
  width: 100%;
  padding: 10px 14px;
  border: 1px solid var(--border);
  border-radius: 12px;
  font-size: 14px;
  transition: border-color 0.2s, box-shadow 0.2s;
  background: #fff;
}
.form-control:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(22, 119, 255, 0.12);
}
textarea.form-control { min-height: 100px; resize: vertical; }
.form-row { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 16px; }
.form-hint { font-size: 12px; color: var(--text-secondary); margin-top: 6px; font-weight: 400; }
.form-check { display: flex; align-items: center; gap: 8px; margin-bottom: 8px; }
.form-check input { width: 16px; height: 16px; accent-color: var(--primary); }

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 10px 20px;
  border-radius: 12px;
  font-size: 14px;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: all 0.2s;
  text-decoration: none;
}
.btn-primary {
  background: var(--primary-gradient);
  color: #fff;
  box-shadow: 0 4px 14px rgba(22, 119, 255, 0.3);
}
.btn-primary:hover {
  color: #fff;
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(22, 119, 255, 0.35);
}
.btn-secondary {
  background: #fff;
  color: var(--text);
  border: 1px solid var(--border);
}
.btn-secondary:hover { border-color: var(--primary); color: var(--primary); }
.btn-danger { background: #fff2f0; color: #ff4d4f; border: 1px solid #ffccc7; }
.btn-danger:hover { background: #ff4d4f; color: #fff; }
.btn-sm { padding: 6px 12px; font-size: 13px; border-radius: 10px; }
.btn-link { background: none; border: none; color: var(--primary); padding: 0; cursor: pointer; font-weight: 500; }

/* Table */
.table-wrap { overflow-x: auto; }
table.data-table {
  width: 100%;
  border-collapse: collapse;
}
table.data-table th,
table.data-table td {
  padding: 14px 16px;
  text-align: left;
  border-bottom: 1px solid var(--border);
}
table.data-table th {
  font-size: 12px;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  background: #fafbfc;
}
table.data-table tbody tr:hover { background: #fafcff; }
table.data-table td { font-weight: 400; color: var(--text); }

/* Badge */
.badge {
  display: inline-block;
  padding: 4px 10px;
  border-radius: 8px;
  font-size: 12px;
  font-weight: 600;
}
.badge-success { background: #f6ffed; color: #52c41a; }
.badge-muted { background: #f5f5f5; color: #8c8c8c; }
.badge-hot { background: #fff7e6; color: #fa8c16; }

/* Alert */
.alert {
  padding: 12px 16px;
  border-radius: 12px;
  margin-bottom: 20px;
  font-size: 14px;
}
.alert-success { background: #f6ffed; color: #389e0d; border: 1px solid #b7eb8f; }
.alert-error { background: #fff2f0; color: #cf1322; border: 1px solid #ffccc7; }

/* Quick links */
.quick-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: 16px;
}
.quick-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 24px 16px;
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  transition: all 0.2s;
  color: var(--text);
  text-decoration: none;
}
.quick-item:hover {
  border-color: var(--primary);
  box-shadow: var(--shadow);
  transform: translateY(-2px);
  color: var(--primary);
}
.quick-item .qi-icon { font-size: 32px; margin-bottom: 10px; }
.quick-item .qi-text { font-size: 13px; font-weight: 600; }

/* Chart */
.chart-box { height: 280px; padding: 16px 0; }

/* Pagination */
.pagination { display: flex; gap: 6px; margin-top: 20px; flex-wrap: wrap; }
.pagination a, .pagination span {
  padding: 8px 14px;
  border-radius: 10px;
  border: 1px solid var(--border);
  font-size: 13px;
  color: var(--text);
}
.pagination a:hover { border-color: var(--primary); color: var(--primary); }
.pagination .active span { background: var(--primary); color: #fff; border-color: var(--primary); }

/* Dynamic rows */
.io-block {
  border: 1px dashed var(--border);
  border-radius: 12px;
  padding: 16px;
  margin-bottom: 12px;
  position: relative;
  background: #fafcff;
}
.io-block .remove-io {
  position: absolute;
  top: 12px;
  right: 12px;
}
.sortable-item { cursor: grab; }
.sortable-item:active { cursor: grabbing; }

.tabs { display: flex; gap: 8px; margin-bottom: 20px; border-bottom: 1px solid var(--border); }
.tab-link {
  padding: 10px 20px;
  color: var(--text-secondary);
  font-weight: 500;
  border-bottom: 2px solid transparent;
  margin-bottom: -1px;
}
.tab-link.active { color: var(--primary); border-bottom-color: var(--primary); font-weight: 600; }

.empty-tip { text-align: center; padding: 48px; color: var(--text-secondary); }

@media (max-width: 900px) {
  .sidebar { transform: translateX(-100%); }
  .main-wrap { margin-left: 0; }
}