/* 底部导航：白天模式浅色底，选中项图标下衬紫色色块、Material Icons */
.mobile-bottom-nav {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  height: 92px;
  padding: 10px 0 16px;
  background-color: #fff;
  display: flex;
  justify-content: space-around;
  align-items: center;
  border-top: 1px solid #eee;
  border-radius: 20px 20px 0 0;
  box-shadow: 0 -2px 12px rgba(0,0,0,0.06);
  z-index: 1050;
}

.mobile-bottom-nav .nav-item {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-decoration: none;
  color: #6b7280;
  transition: color 0.2s, transform 0.2s;
  gap: 6px;
}

.mobile-bottom-nav .nav-item .icon-wrap {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 56px;
  height: 42px;
  border-radius: 14px;
  transition: background-color 0.2s;
}

.mobile-bottom-nav .nav-item .icon-wrap .material-icons {
  font-size: 32px;
}

.mobile-bottom-nav .nav-item.active {
  color: #5B41E1;
}

.mobile-bottom-nav .nav-item.active .icon-wrap {
  background-color: rgba(91, 65, 225, 0.25);
}

.mobile-bottom-nav .nav-item.active .icon-wrap .material-icons {
  color: #5B41E1;
}

.mobile-bottom-nav .nav-item span:not(.material-icons) {
  font-size: 14px;
  font-weight: 500;
}

@media (max-width: 991.98px) {
  body { padding-bottom: 92px !important; }
  .topheader { padding: 0 10px 0 20px; }
  .logo-name { font-size: 16px; }
}

[data-bs-theme="dark"] .mobile-bottom-nav {
  background-color: #1f2937;
  box-shadow: 0 -4px 20px rgba(0,0,0,0.3);
}

[data-bs-theme="dark"] .mobile-bottom-nav .nav-item {
  color: #9ca3af;
}

[data-bs-theme="dark"] .mobile-bottom-nav .nav-item.active {
  color: #7c3aed;
}

[data-bs-theme="dark"] .mobile-bottom-nav .nav-item.active .icon-wrap {
  background-color: rgba(124, 58, 237, 0.25);
}

[data-bs-theme="dark"] .mobile-bottom-nav .nav-item.active .icon-wrap .material-icons {
  color: #a78bfa;
}