/* ========================================
   顶部导航栏样式
   ======================================== */

.site-header {
  background: var(--color-bg-dark);
  color: var(--color-text-inverse);
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: var(--shadow-md);
}

.header-top {
  background: rgba(0,0,0,0.2);
  padding: var(--space-1) 0;
  font-size: var(--text-xs);
}

.header-top .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.header-top a {
  color: var(--color-text-inverse);
  opacity: 0.7;
  margin-left: var(--space-4);
}

.header-top a:hover {
  opacity: 1;
  color: var(--color-accent-light);
}

.header-main {
  padding: var(--space-3) 0;
}

.header-main .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-6);
}

/* Logo */
.logo {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  text-decoration: none;
  color: var(--color-text-inverse);
  flex-shrink: 0;
}

.logo-icon {
  width: 42px;
  height: 42px;
  background: var(--color-primary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-display);
  font-size: var(--text-xl);
  color: var(--color-accent-light);
  border: 2px solid var(--color-accent);
}

.logo-text {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: 700;
  letter-spacing: 2px;
}

.logo-subtitle {
  font-size: var(--text-xs);
  opacity: 0.6;
  letter-spacing: 1px;
}

/* 搜索框 */
.header-search {
  flex: 1;
  max-width: 480px;
  position: relative;
}

.header-search input,
.header-search-form input {
  width: 100%;
  padding: var(--space-3) var(--space-4);
  padding-right: 48px;
  border-radius: var(--radius-xl);
  border: 1px solid rgba(255,255,255,0.2);
  background: rgba(255,255,255,0.1);
  color: var(--color-text-inverse);
  font-size: var(--text-sm);
  transition: all var(--transition-fast);
}

.header-search input::placeholder,
.header-search-form input::placeholder {
  color: rgba(255,255,255,0.5);
}

.header-search input:focus,
.header-search-form input:focus {
  outline: none;
  border-color: var(--color-accent);
  background: rgba(255,255,255,0.15);
}

.header-search button,
.header-search-form button {
  position: absolute;
  right: 4px;
  top: 50%;
  transform: translateY(-50%);
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--color-primary);
  color: var(--color-text-inverse);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--text-sm);
}

.header-search button:hover,
.header-search-form button:hover {
  background: var(--color-primary-light);
}

.header-search-form {
  position: relative;
}

/* 用户操作区 */
.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  flex-shrink: 0;
}

.header-actions a {
  color: var(--color-text-inverse);
  font-size: var(--text-sm);
  opacity: 0.85;
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.header-actions a:hover {
  opacity: 1;
  color: var(--color-accent-light);
}

/* 主导航 */
.main-nav {
  background: var(--color-primary);
  border-top: 1px solid rgba(255,255,255,0.1);
}

.main-nav .container {
  display: flex;
  align-items: center;
}

.nav-list {
  display: flex;
  width: 100%;
}

.nav-item {
  position: relative;
}

.nav-item > a {
  display: block;
  padding: var(--space-3) var(--space-5);
  color: var(--color-text-inverse);
  font-size: var(--text-sm);
  font-weight: 500;
  transition: background var(--transition-fast);
  white-space: nowrap;
}

.nav-item > a:hover,
.nav-item.active > a,
.nav-item.current-menu-item > a {
  background: rgba(255,255,255,0.15);
  color: var(--color-accent-light);
}

/* 下拉菜单 */
.nav-dropdown {
  position: absolute;
  top: 100%;
  left: 0;
  min-width: 200px;
  background: var(--color-bg-card);
  border-radius: 0 0 var(--radius-md) var(--radius-md);
  box-shadow: var(--shadow-lg);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-4px);
  transition: all var(--transition-fast);
  z-index: 100;
  border: 1px solid var(--color-border-light);
}

.nav-item:hover .nav-dropdown {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.nav-dropdown a {
  display: block;
  padding: var(--space-3) var(--space-4);
  color: var(--color-text);
  font-size: var(--text-sm);
  border-bottom: 1px solid var(--color-border-light);
}

.nav-dropdown a:last-child {
  border-bottom: none;
}

.nav-dropdown a:hover {
  background: var(--color-bg-alt);
  color: var(--color-primary);
}

/* 移动端菜单按钮 */
.mobile-menu-btn {
  display: none;
  width: 44px;
  height: 44px;
  align-items: center;
  justify-content: center;
  color: var(--color-text-inverse);
  font-size: var(--text-xl);
}

/* 移动端响应式 */
@media (max-width: 768px) {
  .header-search {
    display: none;
  }

  .header-top {
    display: none;
  }

  .mobile-menu-btn {
    display: flex;
  }

  .main-nav .container {
    flex-direction: column;
  }

  .nav-list {
    flex-direction: column;
    display: none;
  }

  .nav-list.active {
    display: flex;
  }

  .nav-item > a {
    padding: var(--space-4) var(--space-4);
    border-bottom: 1px solid rgba(255,255,255,0.1);
  }

  .nav-dropdown {
    position: static;
    opacity: 1;
    visibility: visible;
    transform: none;
    box-shadow: none;
    border: none;
    background: rgba(0,0,0,0.1);
  }

  .nav-dropdown a {
    color: var(--color-text-inverse);
    padding-left: var(--space-8);
    border-bottom-color: rgba(255,255,255,0.05);
  }
}