/* 
 * 头部导航样式
 */

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 100;
  background: transparent;
  transition: background var(--transition-normal), box-shadow var(--transition-normal);
}

.site-header.scrolled {
  background: rgba(12, 14, 18, 0.85);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 80px;
}

.logo {
  flex-shrink: 0;
}

.logo img {
  height: 32px;
  width: auto;
}

.main-nav {
  display: flex;
  margin-left: var(--spacing-6);
}

.main-nav ul {
  display: flex;
  list-style: none;
}

.main-nav ul li {
  margin: 0 var(--spacing-4);
}

.main-nav ul li a {
  position: relative;
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-gray-5);
  padding: var(--spacing-2) 0;
  transition: color var(--transition-fast);
}

.main-nav ul li a:hover {
  color: var(--color-white);
}

.main-nav ul li a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--gradient-primary);
  transition: width var(--transition-fast);
}

.main-nav ul li a:hover::after {
  width: 100%;
}

.header-actions {
  display: flex;
  align-items: center;
}

.header-actions .btn {
  margin-left: var(--spacing-3);
}

.mobile-menu-toggle {
  display: none;
  background: transparent;
  border: none;
  width: 28px;
  height: 24px;
  position: relative;
  cursor: pointer;
  margin-left: var(--spacing-3);
}

.mobile-menu-toggle span {
  display: block;
  position: absolute;
  height: 2px;
  width: 100%;
  background: var(--color-white);
  border-radius: 2px;
  opacity: 1;
  left: 0;
  transform: rotate(0deg);
  transition: var(--transition-fast);
}

.mobile-menu-toggle span:nth-child(1) {
  top: 0;
}

.mobile-menu-toggle span:nth-child(2) {
  top: 10px;
}

.mobile-menu-toggle span:nth-child(3) {
  top: 20px;
}

.mobile-menu-toggle.active span:nth-child(1) {
  top: 10px;
  transform: rotate(45deg);
}

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

.mobile-menu-toggle.active span:nth-child(3) {
  top: 10px;
  transform: rotate(-45deg);
}

/* 移动菜单 */
.mobile-menu {
  position: fixed;
  top: 80px;
  left: 0;
  width: 100%;
  background: var(--color-dark-2);
  padding: var(--spacing-4) 0;
  z-index: 99;
  transform: translateY(-100%);
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-normal);
  box-shadow: 0 10px 20px rgba(0, 0, 0, 0.2);
}

.mobile-menu.active {
  transform: translateY(0);
  opacity: 1;
  visibility: visible;
}

.mobile-nav ul {
  list-style: none;
}

.mobile-nav ul li {
  margin-bottom: var(--spacing-3);
}

.mobile-nav ul li a {
  display: block;
  font-size: var(--font-size-lg);
  font-weight: 500;
  padding: var(--spacing-2) 0;
  color: var(--color-gray-5);
  transition: color var(--transition-fast);
}

.mobile-nav ul li a:hover {
  color: var(--color-white);
}

.mobile-nav ul li a.mobile-register {
  color: var(--color-primary-light);
}

/* 响应式调整 */
@media (max-width: 1024px) {
  .header-inner {
    height: 70px;
  }
  
  .main-nav ul li {
    margin: 0 var(--spacing-3);
  }
}

@media (max-width: 768px) {
  .main-nav {
    display: none;
  }
  
  .header-actions .btn {
    display: none;
  }
  
  .mobile-menu-toggle {
    display: block;
  }
  
  .mobile-menu {
    top: 70px;
  }
}