/**
 * CN 低代码品牌学习中心 — 统一二级导航
 */
.platform-subnav {
  position: fixed;
  top: 55px;
  left: 0;
  right: 0;
  z-index: 40;
  background: linear-gradient(90deg, #059669, #10b981);
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.12);
}

.platform-subnav-desktop {
  display: none;
  align-items: center;
  justify-content: center;
  flex-wrap: nowrap;
  gap: 0.25rem;
  padding: 0.5rem 0;
  overflow-x: auto;
  scrollbar-width: none;
}

.platform-subnav-desktop::-webkit-scrollbar {
  display: none;
}

.platform-subnav-link {
  flex-shrink: 0;
  padding: 0.45rem 0.9rem;
  border-radius: 0.5rem;
  color: rgba(255, 255, 255, 0.95);
  font-size: 0.875rem;
  font-weight: 500;
  text-decoration: none;
  white-space: nowrap;
  transition: background 0.2s ease, color 0.2s ease;
}

.platform-subnav-link:hover {
  background: rgba(255, 255, 255, 0.14);
  color: #fff;
}

.platform-subnav-link.is-active {
  background: rgba(255, 255, 255, 0.24);
  color: #fff;
  font-weight: 600;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.12);
}

.platform-subnav-back {
  opacity: 0.9;
}

.platform-subnav-mobile {
  display: block;
  padding: 0.4rem 0;
}

.platform-subnav-select {
  width: 100%;
  padding: 0.45rem 0.75rem;
  border-radius: 0.5rem;
  border: 1px solid rgba(255, 255, 255, 0.35);
  background: rgba(255, 255, 255, 0.12);
  color: #fff;
  font-size: 0.875rem;
}

@media (min-width: 768px) {
  .platform-subnav-desktop {
    display: flex;
  }
  .platform-subnav-mobile {
    display: none;
  }
}