/* ========================================
   文件说明：头部导航样式
   文件路径：css/components/header.css
   ======================================== */

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background: var(--color-bg-card);
  box-shadow: var(--shadow-sm);
  z-index: var(--z-sticky);
  transition: box-shadow var(--transition-base);
}

.site-header--scrolled {
  box-shadow: var(--shadow-md);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  max-width: var(--container-xl);
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

.header-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
}

.header-logo__img {
  height: 40px;
  width: 40px;
  border-radius: 50%;
  box-shadow: 0 2px 8px rgba(45, 106, 79, 0.15);
  transition: transform var(--transition-base);
}

.header-logo:hover .header-logo__img {
  transform: scale(1.08);
}

.header-logo__text {
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: var(--color-primary);
  letter-spacing: 2px;
}

.header-nav {
  display: flex;
  align-items: center;
  gap: var(--spacing-xl);
}

.header-nav__link {
  font-size: var(--font-size-base);
  color: var(--color-text-secondary);
  transition: color var(--transition-fast);
  padding: var(--spacing-sm) 0;
  position: relative;
}

.header-nav__link:hover,
.header-nav__link--active {
  color: var(--color-primary);
}

.header-nav__link--active::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--color-primary);
  border-radius: 1px;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

/* 移动端汉堡菜单 */
.header-menu-btn {
  display: none;
  width: 32px;
  height: 32px;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
}

.header-menu-btn span {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--color-text-primary);
  transition: all var(--transition-fast);
}

.header-menu-btn.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.header-menu-btn.active span:nth-child(2) {
  opacity: 0;
}

.header-menu-btn.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* 移动端导航 */
.mobile-nav {
  display: none;
  position: fixed;
  top: var(--header-height);
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--color-bg-card);
  z-index: var(--z-fixed);
  padding: var(--spacing-lg);
  overflow-y: auto;
}

.mobile-nav.active {
  display: block;
  animation: fadeIn var(--transition-fast);
}

.mobile-nav__link {
  display: block;
  padding: var(--spacing-md) 0;
  font-size: var(--font-size-lg);
  color: var(--color-text-secondary);
  border-bottom: 1px solid var(--color-border-light);
}

.mobile-nav__link:hover,
.mobile-nav__link--active {
  color: var(--color-primary);
}

@media (max-width: 768px) {
  .header-nav { display: none; }
  .header-menu-btn { display: flex; }
}