/* 三年级3班积分系统 — 主题 */
:root {
  --brand-primary: #2C3E50;
  --brand-accent: #FF7F50;
  --brand-success: #27AE60;
  --brand-warn: #F39C12;
}

body {
  background: linear-gradient(180deg, #f8f9fc 0%, #eef2f7 100%);
  min-height: 100vh;
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei",
    "Segoe UI", Arial, sans-serif;
  color: #2C3E50;
}

.app-nav {
  background: linear-gradient(90deg, #2C3E50 0%, #34495E 100%) !important;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
}
.app-nav .nav-link.active,
.app-nav .nav-link:hover { color: var(--brand-accent) !important; }
.app-nav .navbar-brand { letter-spacing: 1px; }

main { max-width: 1280px; margin: 0 auto; }

footer { background: #fff; border-top: 1px solid #e9ecef; }

/* 卡片 / 表格 */
.card {
  border: 0;
  border-radius: 12px;
  box-shadow: 0 1px 4px rgba(44, 62, 80, 0.06);
  overflow: hidden;
}
.card-header {
  background: #f6f8fa;
  font-weight: 600;
  border-bottom: 1px solid #eef2f7;
}
.card.stat-card {
  border: 0;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.06);
}
.card.stat-card .display-6 { font-size: 1.8rem; }

.table > :not(caption) > * > * { padding: 0.55rem 0.6rem; }
.table thead th { font-weight: 600; color: #4a5568; font-size: 0.85rem; }

.table-warning td { background: #FFF8E1 !important; }

.btn { border-radius: 8px; }
.btn-primary { background: var(--brand-primary); border-color: var(--brand-primary); }
.btn-primary:hover { background: #1f2c3a; border-color: #1f2c3a; }

.badge { font-weight: 500; }

/* 移动端微调 */
@media (max-width: 768px) {
  .display-6 { font-size: 1.4rem; }
  .card-body { padding: 0.85rem; }
  .table th, .table td { font-size: 0.85rem; }
  .navbar-nav .nav-link { padding-left: 0.5rem; }
}