:root {
    --primary-color: #2563eb;
    --secondary-color: #3b82f6;
    --accent-color: #60a5fa;
    --primary-rgb: 37, 99, 235;
    --background-color: #f8fafc;
    --card-background: rgba(255, 255, 255, 0.9);
    --text-color: #1e293b;
    --text-muted: #64748b;
    --border-radius: 0.75rem;
    --box-shadow: 0 4px 10px rgba(0, 0, 0, 0.08);
    --hover-shadow: 0 10px 20px rgba(0, 0, 0, 0.12);
}

body {
    background: var(--background-color);
    background-image: 
        radial-gradient(at 40% 20%, rgba(37,99,235,0.1) 0px, transparent 50%),
        radial-gradient(at 80% 0%, rgba(96,165,250,0.1) 0px, transparent 50%),
        radial-gradient(at 0% 50%, rgba(37,99,235,0.1) 0px, transparent 50%);
    background-attachment: fixed;
    color: var(--text-color);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

.main-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 2rem 1rem;
}

/* 面包屑导航 */
.breadcrumb {
    padding: 0.75rem 1rem;
    background-color: rgba(255, 255, 255, 0.8);
    border-radius: var(--border-radius);
    box-shadow: 0 1px 5px rgba(0, 0, 0, 0.05);
    margin-bottom: 1.5rem;
    backdrop-filter: blur(5px);
}

.breadcrumb-item + .breadcrumb-item::before {
    content: "›";
    color: var(--primary-color);
    font-weight: bold;
    font-size: 1.2rem;
    line-height: 1;
}

.breadcrumb-item a {
    color: var(--primary-color);
    text-decoration: none;
    transition: all 0.3s ease;
    font-weight: 500;
}

.breadcrumb-item a:hover {
    color: var(--secondary-color);
    text-decoration: underline;
}

.breadcrumb-item.active {
    color: var(--text-muted);
}

/* 页面标题 */
.page-title {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 1.75rem;
    position: relative;
    display: block;
    border-bottom: 2px solid rgba(37,99,235,0.1);
    padding-bottom: 0.75rem;
}

.page-title small {
    font-size: 0.95rem;
    color: var(--text-muted);
    font-weight: normal;
    line-height: 1.5;
    margin-top: 0.5rem;
}

/* 广告样式 */
.advertisement {
    margin-bottom: 2rem;
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--box-shadow);
    transition: transform 0.3s ease;
    background: white;
    max-width: 100%;
}

.advertisement:hover {
    transform: translateY(-3px);
    box-shadow: var(--hover-shadow);
}

.advertisement img {
    width: 100%;
    height: auto;
    display: block;
}

/* 文章列表 */
.article-list {
    margin-bottom: 2rem;
}

.article-item {
    background: var(--card-background);
    border-radius: var(--border-radius);
    margin-bottom: 1.75rem;
    overflow: hidden;
    box-shadow: var(--box-shadow);
    transition: all 0.3s ease;
    position: relative;
    border: 1px solid rgba(0,0,0,0.03);
}

.article-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--hover-shadow);
}

.article-image {
    display: block;
    overflow: hidden;
    height: 100%;
    border-radius: 0.5rem;
    margin: 0.75rem;
}

.article-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
    border-radius: 0.5rem;
}

.article-image:hover img {
    transform: scale(1.05);
}

.article-content {
    padding: 1.5rem;
}

.article-title {
    font-size: 1.4rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
    line-height: 1.4;
}

.article-title a {
    color: var(--text-color);
    text-decoration: none;
    transition: color 0.3s ease;
}

.article-title a:hover {
    color: var(--primary-color);
}

.article-meta {
    color: var(--text-muted);
    font-size: 0.875rem;
    margin-bottom: 1.25rem;
    display: flex;
    flex-wrap: wrap;
    gap: 1.25rem;
}

.article-date, .article-category {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.article-meta i {
    color: var(--primary-color);
}

.article-category a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color 0.3s ease;
    font-weight: 500;
}

.article-category a:hover {
    color: var(--secondary-color);
    text-decoration: underline;
}

.article-summary {
    color: #475569;
    font-size: 1rem;
    line-height: 1.7;
    margin-bottom: 1.5rem;
}

.article-item .btn-primary {
    background-color: var(--primary-color);
    border-color: var(--primary-color);
    transition: all 0.3s ease;
    border-radius: 2rem;
    padding: 0.375rem 1.25rem;
    font-weight: 500;
}

.article-item .btn-primary:hover {
    background-color: var(--secondary-color);
    border-color: var(--secondary-color);
    transform: translateX(3px);
    box-shadow: 0 3px 5px rgba(0,0,0,0.1);
}

/* 侧边栏样式 */
.card {
    border: none;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    overflow: hidden;
    margin-bottom: 2rem;
    background-color: var(--card-background);
    transition: transform 0.3s ease;
}

.card:hover {
    transform: translateY(-3px);
    box-shadow: var(--hover-shadow);
}

.card-header {
    background-color: rgba(37,99,235,0.05);
    border-bottom: 1px solid rgba(37,99,235,0.1);
    padding: 1.25rem 1.5rem;
}

.card-header h5 {
    color: var(--primary-color);
    font-weight: 600;
    margin: 0;
    font-size: 1.1rem;
}

.list-group-item {
    background-color: transparent;
    border-color: rgba(0,0,0,0.05);
    transition: all 0.3s ease;
    padding: 0.75rem 1.25rem;
}

.list-group-item:hover {
    background-color: rgba(37,99,235,0.05);
}

.list-group-item a {
    color: var(--text-color);
    display: block;
    transition: color 0.3s ease;
}

.list-group-item a:hover {
    color: var(--primary-color);
}

.list-group-item a.fw-bold {
    color: var(--primary-color);
}

/* 侧栏标题占位 */
.sidebar-title-placeholder {
    height: 3.5rem;
    visibility: hidden;
}

/* 随机文章链接 */
.random-article-link {
    display: block;
    color: var(--text-color);
    transition: all 0.3s ease;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    padding: 0.25rem 0;
}

.random-article-link:hover {
    color: var(--primary-color);
    transform: translateX(3px);
}

.badge {
    font-weight: 500;
    transition: all 0.3s ease;
    padding: 0.4em 0.65em;
}

.list-group-item:hover .badge {
    background-color: var(--secondary-color) !important;
    transform: scale(1.05);
}

.friend-links {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    padding: 0.5rem;
}

.friend-link {
    display: inline-block;
    padding: 0.35rem 0.9rem;
    background-color: rgba(37,99,235,0.1);
    color: var(--primary-color);
    border-radius: 2rem;
    font-size: 0.9rem;
    transition: all 0.3s ease;
    text-decoration: none;
}

.friend-link:hover {
    color: white;
    transform: translateY(-2px);
}

/* 警告信息 */
.alert-info {
    background-color: rgba(96,165,250,0.1);
    border-color: rgba(96,165,250,0.2);
    color: var(--primary-color);
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
}

/* 响应式调整 */
@media (max-width: 767.98px) {
    .article-item {
        margin-bottom: 1.5rem;
    }
    
    .article-content {
        padding: 1.25rem;
    }
    
    .article-title {
        font-size: 1.25rem;
    }
    
    .article-summary {
        font-size: 0.95rem;
        margin-bottom: 1.25rem;
    }
    
    .page-title {
        font-size: 1.75rem;
    }
}

@media (max-width: 575.98px) {
    .main-container {
        padding: 1.5rem 0.75rem;
    }
    
    .article-meta {
        flex-direction: column;
        gap: 0.5rem;
    }
    
    .article-image {
        margin: 0.5rem 0.5rem 0;
    }
}