/* 页头样式 */
#main-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    background-color: rgba(255, 255, 255, 0.5);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: none;
    transition: all var(--transition-normal);
    height: var(--header-height);
}

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

.logo,
.main-nav,
.header-actions {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
    height: 100%;
}

.logo {
    display: flex;
    align-items: center;
    text-decoration: none;
    color: var(--text-primary);
    gap: var(--spacing-sm);
}

.logo img {
    height: 28px;
    margin-right: var(--spacing-sm);
}

.logo-text {
    font-size: 1.1rem;
    font-weight: 600;
    letter-spacing: -0.01em;
}

.main-nav {
    display: none;
}

@media (min-width: 768px) {
    .main-nav {
        display: flex;
        gap: var(--spacing-lg);
        height: 100%;
    }

    .nav-item {
        font-size: 0.9rem;
        font-weight: 500;
        color: var(--text-secondary);
        text-decoration: none;
        padding: 0 12px;
        height: 36px;
        display: inline-flex;
        align-items: center;
        border-radius: 8px;
        background-color: transparent;
        transition: color var(--transition-fast), background-color var(--transition-fast);
    }

    .nav-item:hover {
        color: var(--text-primary);
        background-color: var(--gray-100);
    }

    .nav-item.active {
        color: var(--text-primary);
        background-color: transparent;
    }
}

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

.header-actions .btn {
    height: 36px;
    display: inline-flex;
    align-items: center;
    padding: 0 16px;
}

.search-container {
    position: relative;
    display: none;
}

@media (min-width: 768px) {
    .search-container {
        display: block;
    }
}

#search-input {
    background-color: transparent;
    border: none;
    border-radius: var(--border-radius-sm);
    padding: 0 12px 0 32px;
    width: 180px;
    height: 36px;
    font-size: 0.9rem;
    line-height: 1;
    transition: all var(--transition-normal);
}

#search-input:focus {
    width: 240px;
    background-color: var(--light-color);
    box-shadow: var(--shadow-md);
}

#search-button {
    position: absolute;
    left: 10px;
    top: 50%;
    transform: translateY(-50%);
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
}

/* 移动端菜单 */
.mobile-menu-toggle {
    display: block;
    width: 30px;
    height: 30px;
    cursor: pointer;
    background: none;
    border: none;
    padding: 0;
    z-index: 1001;
}

.mobile-menu-toggle span {
    display: block;
    width: 22px;
    height: 2px;
    background-color: var(--text-primary);
    margin: 5px auto;
    transition: all var(--transition-fast);
}

@media (min-width: 768px) {
    .mobile-menu-toggle {
        display: none;
    }
}

.mobile-nav {
    position: fixed;
    top: var(--header-height);
    left: 0;
    width: 100%;
    height: calc(100vh - var(--header-height));
    background-color: var(--light-color);
    transform: translateX(-100%);
    transition: transform var(--transition-normal);
    padding: var(--spacing-xl);
    display: flex;
    flex-direction: column;
}

.mobile-nav.active {
    transform: translateX(0);
}

.mobile-nav-item {
    color: var(--text-primary);
    text-decoration: none;
    font-size: 1.5rem;
    font-weight: 600;
    padding: var(--spacing-md) 0;
    border-bottom: 1px solid var(--gray-200);
}