/* 顶部导航栏样式 */
.top-nav {
    grid-area: header;
    background-color: var(--bg-card);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
    transition: all var(--transition);
}

.nav-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
    padding: 0 var(--space-md);
    max-width: 100%;
}

/* Logo和品牌 */
.nav-brand {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    flex-shrink: 0;
}

.logo svg {
    display: block;
    transition: transform var(--transition-fast);
}

.logo:hover svg {
    transform: scale(1.05);
}

.site-title {
    font-size: var(--font-size-lg);
    font-weight: var(--font-weight-bold);
    color: var(--text-primary);
    margin: 0;
}

/* 搜索区域 */
.nav-search {
    flex: 1;
    max-width: 500px;
    margin: 0 var(--space-lg);
}

.search-container {
    position: relative;
    width: 100%;
}

.search-input {
    width: 100%;
    height: 40px;
    padding: 0 var(--space-sm) 0 var(--space-xl);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    font-size: var(--font-size-base);
    transition: all var(--transition-fast);
}

.search-input:focus {
    outline: none;
    border-color: var(--primary-color);
    background-color: var(--bg-card);
    box-shadow: 0 0 0 3px rgba(91, 106, 255, 0.1);
}

.search-input::placeholder {
    color: var(--text-muted);
}

.search-icon {
    position: absolute;
    left: var(--space-sm);
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-muted);
    pointer-events: none;
}

/* 导航操作区 */
.nav-actions {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    flex-shrink: 0;
}

/* 主题切换按钮 */
.theme-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: var(--border-radius);
    background-color: transparent;
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

.theme-toggle:hover {
    background-color: var(--bg-hover);
    color: var(--text-primary);
}

.theme-toggle:focus {
    background-color: var(--bg-hover);
}

.theme-icon {
    transition: all var(--transition-fast);
}

.theme-icon-dark {
    display: none;
}

[data-theme="dark"] .theme-icon-light {
    display: none;
}

[data-theme="dark"] .theme-icon-dark {
    display: block;
}

/* 移动端菜单按钮 */
.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    width: 40px;
    height: 40px;
    border-radius: var(--border-radius);
    background-color: transparent;
    transition: all var(--transition-fast);
}

.mobile-menu-toggle:hover {
    background-color: var(--bg-hover);
}

.hamburger-line {
    width: 20px;
    height: 2px;
    background-color: var(--text-primary);
    margin: 2px 0;
    transition: all var(--transition-fast);
    border-radius: 1px;
}

.mobile-menu-toggle[aria-expanded="true"] .hamburger-line:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.mobile-menu-toggle[aria-expanded="true"] .hamburger-line:nth-child(2) {
    opacity: 0;
}

.mobile-menu-toggle[aria-expanded="true"] .hamburger-line:nth-child(3) {
    transform: rotate(-45deg) translate(7px, -6px);
}

/* 响应式设计 */
@media (max-width: 768px) {
    .nav-content {
        padding: 0 var(--space-sm);
    }
    
    .nav-search {
        margin: 0 var(--space-sm);
        max-width: none;
    }
    
    .mobile-menu-toggle {
        display: flex;
    }
    
    .site-title {
        font-size: var(--font-size-base);
    }
}

@media (max-width: 480px) {
    .nav-brand {
        gap: var(--space-xs);
    }
    
    .site-title {
        display: none;
    }
    
    .nav-search {
        margin: 0 var(--space-xs);
    }
    
    .search-input {
        font-size: var(--font-size-sm);
    }
}