:root {
    --red-color: #ff4757;
    --red-light: #ff6b81;
    --red-dark: #ff3838;
    --black-color: #2f3542;
    --black-light: #57606f;
    --black-dark: #1e272e;
    --white: #ffffff;
    --gray-light: #f1f2f6;
    --gray: #a4b0be;
    --success: #2ed573;
    --warning: #ffa502;
    --shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
    --radius: 12px;
    --transition: all 0.3s ease;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Noto Sans SC', sans-serif;
    background: var(--gray-light);
    color: var(--black-color);
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 导航栏 */
.navbar {
    background: var(--white);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 20px;
}

.nav-brand h1 {
    font-size: 1.8rem;
    color: var(--red-color);
    display: flex;
    align-items: center;
    gap: 10px;
}

.nav-menu {
    display: flex;
    gap: 30px;
    align-items: center;
}

.nav-item {
    text-decoration: none;
    color: var(--black-light);
    font-weight: 500;
    padding: 8px 16px;
    border-radius: var(--radius);
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-item:hover, .nav-item.active {
    background: var(--red-color);
    color: var(--white);
}

/* 左右分栏布局 */
.split-layout {
    display: flex;
    min-height: 80vh;
    position: relative;
}

.column {
    flex: 1;
    padding: 40px;
    position: relative;
    overflow: hidden;
}

.red-column {
    background: linear-gradient(135deg, #ffcccc 0%, #fff5f5 100%);
}

.black-column {
    background: linear-gradient(135deg, #333333 0%, #444444 100%);
    color: var(--white);
}

.divider {
    position: relative;
    width: 100px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.divider-line {
    width: 4px;
    height: 100%;
    background: var(--white);
    box-shadow: 0 0 20px rgba(0,0,0,0.2);
}

.divider-text {
    position: absolute;
    background: var(--white);
    color: var(--black-color);
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    font-size: 1.2rem;
    box-shadow: var(--shadow);
}

/* 帖子卡片 */
.posts-container {
    display: grid;
    gap: 25px;
    margin-top: 30px;
}

.post-card {
    background: var(--white);
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow);
    display: flex;
    transition: var(--transition);
    animation: fadeIn 0.5s ease;
}

.black-column .post-card {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
}

.post-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.15);
}

.post-cover {
    flex: 0 0 200px;
    position: relative;
    overflow: hidden;
}

.post-cover img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition);
}

.post-card:hover .post-cover img {
    transform: scale(1.1);
}

.top-badge {
    position: absolute;
    top: 10px;
    left: 10px;
    background: var(--warning);
    color: white;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: bold;
}

.post-content {
    flex: 1;
    padding: 25px;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

.post-title {
    font-size: 1.3rem;
    margin-bottom: 15px;
    line-height: 1.4;
}

.post-title a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
}

.red-column .post-title a:hover {
    color: var(--red-color);
}

.black-column .post-title a:hover {
    color: var(--gray);
}

.tag {
    display: inline-block;
    padding: 2px 10px;
    border-radius: 12px;
    font-size: 0.8rem;
    margin-left: 8px;
    color: white;
    vertical-align: middle;
}

.post-summary {
    color: var(--black-light);
    margin-bottom: 15px;
    line-height: 1.6;
}

.black-column .post-summary {
    color: var(--gray);
}

.post-meta {
    display: flex;
    gap: 20px;
    font-size: 0.9rem;
    color: var(--gray);
}

.post-meta span {
    display: flex;
    align-items: center;
    gap: 5px;
}

/* 分类标签 */
.category-tabs {
    background: var(--white);
    padding: 20px 0;
    box-shadow: 0 4px 20px rgba(0,0,0,0.05);
}

.tab-btn {
    padding: 12px 24px;
    border: 2px solid transparent;
    background: none;
    border-radius: var(--radius);
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    margin-right: 10px;
}

.tab-btn.active {
    background: var(--red-color);
    color: var(--white);
    border-color: var(--red-color);
}

.tab-btn:hover:not(.active) {
    border-color: var(--gray);
}

.btn-post {
    float: right;
    background: linear-gradient(135deg, var(--red-color), var(--red-dark));
    color: white;
    padding: 12px 24px;
    border-radius: var(--radius);
    text-decoration: none;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: var(--transition);
}

.btn-post:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 30px rgba(255, 71, 87, 0.3);
}

/* 动画 */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 响应式设计 */
@media (max-width: 992px) {
    .split-layout {
        flex-direction: column;
    }
    
    .divider {
        width: 100%;
        height: 100px;
        flex-direction: row;
    }
    
    .divider-line {
        width: 100%;
        height: 4px;
    }
    
    .post-card {
        flex-direction: column;
    }
    
    .post-cover {
        flex: 0 0 200px;
    }
}

@media (max-width: 768px) {
    .nav-menu {
        display: none;
    }
    
    .nav-toggle {
        display: block;
        font-size: 1.5rem;
        cursor: pointer;
    }
}