.header {
    background-color: #ffffff;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 30px;
    display: flex;
    justify-content: space-around;
    align-items: center;
    height: 80px;
}

.logo {
    font-size: 1.8rem;
    font-weight: normal;
    color: var(--color-dark);
    letter-spacing: -0.5px;
}

.nav {
    display: flex;
    gap: 3rem;
}

.nav-link {
    text-decoration: none;
    color: var(--color-secondary);
    font-weight: bold;
    transition: color 0.2s ease;
    position: relative;
    font-size: 1.1rem;
}

.nav-link:hover {
    color: var(--color-dark);
}

.nav-link.active {
    color: var(--color-dark);
}

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 100%;
    height: 2px;
    background-color: var(--color-primary);
}

.user-actions {
    display: flex;
    gap: 1.5rem;
    align-items: center;
}

.main-container {
    width: 100%;
    margin: 1.5rem auto;
    padding: 0 30px;
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.post-section {
    background-color: #ffffff;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--box-shadow);
    overflow: hidden;
    padding: 1rem;
}

.section-header {
    padding: 2rem 2rem 1.5rem;
    border-bottom: 1px solid #f1f2f3;
}

.section-header h2 {
    font-size: 1.5rem;
    font-weight: normal;
    color: var(--color-dark);
    margin: 0;
}

/* 首页左右分栏布局 */
.home-layout {
    display: grid;
    grid-template-columns: 350px 1fr;
    grid-template-rows: auto 1fr;
    gap: 10px;
    margin-top: 20px;
}

/* 移动端适配 - 首页布局在小屏幕上的优化 */
@media (max-width: 768px) {
    .home-layout {
        grid-template-columns: 1fr;
        grid-template-rows: auto auto 1fr;
        gap: 15px;
    }
}

/* 将栏目标签栏移动到主题列表上方 */
.category-tabs-container {
    grid-column: 2;
    grid-row: 1;
    margin: 0 0 5px 0;
}

/* 调整置顶主题轮播区位置 */
.pinned-topics-carousel {
    grid-column: 1;
    grid-row: 1 / span 2;
    align-self: start;
    background: #fff;
    border-radius: 12px;
    overflow: hidden;
}

/* 右侧主题列表区域 */
.topics-list-area {
    min-height: 400px;
}

/* 响应式设计 */
@media (max-width: 1024px) {
    .home-layout {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    
    .pinned-topics-carousel {
        order: 1;
        grid-column: 1;
        grid-row: 1;
    }
    
    .topics-list-area {
        order: 2;
        grid-column: 1;
        grid-row: 2;
    }
}

/* 移动端适配 - 确保在小屏幕上正确显示 */
@media (max-width: 768px) {
    .pinned-topics-carousel {
        grid-column: 1;
        grid-row: 1;
    }
    
    .topics-list-area {
        grid-column: 1;
        grid-row: 2;
    }
}

/* 移动端适配 - 顶栏响应式设计 */
@media (max-width: 768px) {
    .header-content {
        padding: 0 15px;
        height: 60px;
    }
    
    .logo {
        font-size: 1.5rem;
    }
    
    .nav {
        display: none;
        position: absolute;
        top: 60px;
        left: 0;
        right: 0;
        background: #ffffff;
        flex-direction: column;
        gap: 0;
        box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
        z-index: 99;
    }
    
    .nav.active {
        display: flex;
    }
    
    .nav-link {
        padding: 15px 20px;
        border-bottom: 1px solid #f1f2f3;
        font-size: 1rem;
    }
    
    .nav-link:last-child {
        border-bottom: none;
    }
    
    .user-actions {
        gap: 1rem;
    }
    
    .mobile-menu-btn {
        display: block;
        background: none;
        border: none;
        font-size: 1.5rem;
        cursor: pointer;
        color: var(--color-dark);
        padding: 5px;
    }
    
    .main-container {
        width: 95%;
        padding: 0 15px;
        margin: 1rem auto;
    }
    
    .post-section {
        padding: 0.8rem;
    }
}

@media (min-width: 769px) {
    .mobile-menu-btn {
        display: none;
    }
    
    .nav {
        display: flex !important;
    }
}

/* 移动端适配 - 顶栏在极小屏幕上的优化 */
@media (max-width: 480px) {
    .header-content {
        padding: 0 10px;
        height: 50px;
    }
    
    .logo {
        font-size: 1.3rem;
    }
    
    .nav {
        top: 50px;
    }
    
    .nav-link {
        padding: 12px 15px;
        font-size: 0.95rem;
    }
    
    .user-actions {
        gap: 0.8rem;
    }
    
    .mobile-menu-btn {
        font-size: 1.3rem;
        padding: 3px;
    }
    
    .main-container {
        width: 100%;
        padding: 0 10px;
        margin: 0.8rem auto;
    }
    
    .post-section {
        padding: 0.6rem;
    }
    
    .section-header {
        padding: 1.5rem 1.5rem 1rem;
    }
    
    .section-header h2 {
        font-size: 1.3rem;
    }
    
    .home-layout {
        margin-top: 15px;
    }
    
    /* 确保主容器在极小屏幕上正确显示 */
    .main-container {
        width: 100%;
        padding: 0 5px;
        margin: 0.5rem auto;
    }
    
    .post-section {
        padding: 0.5rem;
    }
}