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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: #f5f5f5;
    line-height: 1.6;
}

.help-list-page {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

/* Header Section */
.page-header {
    background: linear-gradient(135deg, #1e3a8a 0%, #3b82f6 100%);
    border-radius: 12px;
    padding: 40px;
    margin-bottom: 30px;
    color: white;
    text-align: center;
}

.page-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 20px;
}

.page-subtitle {
    font-size: 1.1rem;
    opacity: 0.9;
    margin-bottom: 30px;
}

.search-container {
    max-width: 600px;
    margin: 0 auto;
}

.search-box {
    display: flex;
    background: white;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

.search-input {
    flex: 1;
    padding: 15px 20px;
    border: none;
    outline: none;
    font-size: 1rem;
    color: #333;
}

    .search-input::placeholder {
        color: #999;
    }

.search-button {
    padding: 15px 30px;
    background: #1890ff;
    color: white;
    border: none;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.3s ease;
}

    .search-button:hover {
        background: #40a9ff;
    }

/* Main Content */
.main-content {
    display: flex;
    gap: 30px;
}

/* Sidebar */
.sidebar {
    width: 250px;
    background: white;
    border-radius: 12px;
    padding: 30px;
    box-shadow: 0 2px 12px rgba(0,0,0,0.08);
    height: fit-content;
    position: sticky;
    top: 20px;
}

.sidebar-title {
    font-size: 1.3rem;
    font-weight: 600;
    color: #333;
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid #1890ff;
}

.category-list {
    list-style: none;
}

.category-item {
    margin-bottom: 8px;
}

.category-link {
    display: block;
    padding: 12px 16px;
    color: #666;
    text-decoration: none;
    border-radius: 6px;
    transition: all 0.3s ease;
    position: relative;
}

    .category-link:hover,
    .category-link.active {
        background: #f0f8ff;
        color: #1890ff;
    }

        .category-link.active::before {
            content: '';
            position: absolute;
            left: 0;
            top: 0;
            bottom: 0;
            width: 3px;
            background: #1890ff;
        }

.category-count {
    float: right;
    background: #e6f7ff;
    color: #1890ff;
    padding: 2px 8px;
    border-radius: 12px;
    font-size: 0.8rem;
}

/* Content Area */
.content-area {
    flex: 1;
}

/* Filter Bar */
.filter-bar {
    background: white;
    border-radius: 12px;
    padding: 20px;
    margin-bottom: 20px;
    box-shadow: 0 2px 12px rgba(0,0,0,0.08);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 15px;
}

.filter-left {
    display: flex;
    align-items: center;
    gap: 15px;
}

.filter-tag {
    padding: 6px 12px;
    background: #f0f8ff;
    color: #1890ff;
    border-radius: 16px;
    font-size: 0.9rem;
    cursor: pointer;
    transition: all 0.3s ease;
}

    .filter-tag:hover,
    .filter-tag.active {
        background: #1890ff;
        color: white;
    }

.sort-select {
    padding: 8px 12px;
    border: 1px solid #d9d9d9;
    border-radius: 6px;
    background: white;
    font-size: 0.9rem;
    cursor: pointer;
}

.results-count {
    color: #666;
    font-size: 0.9rem;
}

/* Articles Grid */
.articles-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.article-card {
    background: white;
    border-radius: 12px;
    padding: 25px;
    box-shadow: 0 2px 12px rgba(0,0,0,0.08);
    transition: all 0.3s ease;
    cursor: pointer;
}

    .article-card:hover {
        transform: translateY(-4px);
        box-shadow: 0 8px 20px rgba(0,0,0,0.12);
    }

.article-category {
    display: inline-block;
    background: #f0f8ff;
    color: #1890ff;
    padding: 4px 12px;
    border-radius: 12px;
    font-size: 0.8rem;
    margin-bottom: 12px;
}

.article-title {
    font-size: 1.2rem;
    font-weight: 600;
    color: #333;
    margin-bottom: 10px;
    line-height: 1.4;
}

.article-excerpt {
    color: #666;
    font-size: 0.9rem;
    line-height: 1.5;
    margin-bottom: 15px;
}

.article-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.8rem;
    color: #999;
}

.article-date {
    display: flex;
    align-items: center;
    gap: 5px;
}

.article-views {
    display: flex;
    align-items: center;
    gap: 5px;
}

/* Pagination */
.pagination {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 10px;
    margin-top: 30px;
}

    .pagination button {
        padding: 8px 12px;
        border: 1px solid #d9d9d9;
        background: white;
        color: #666;
        border-radius: 6px;
        cursor: pointer;
        transition: all 0.3s ease;
    }

        .pagination button:hover,
        .pagination button.active {
            background: #1890ff;
            color: white;
            border-color: #1890ff;
        }

        .pagination button:disabled {
            background: #f5f5f5;
            color: #ccc;
            cursor: not-allowed;
        }

/* Empty State */
.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: #999;
}

.empty-icon {
    font-size: 4rem;
    margin-bottom: 20px;
    opacity: 0.5;
}

.empty-title {
    font-size: 1.2rem;
    margin-bottom: 10px;
}

.empty-description {
    font-size: 0.9rem;
}

/* Responsive Design */
@media (max-width: 992px) {
    .main-content {
        flex-direction: column;
    }

    .sidebar {
        width: 100%;
        position: static;
    }

    .articles-grid {
        grid-template-columns: 1fr;
    }

    .filter-bar {
        flex-direction: column;
        align-items: flex-start;
    }
}

@media (max-width: 768px) {
    .help-list-page {
        padding: 10px;
    }

    .page-header {
        padding: 30px 20px;
    }

    .page-title {
        font-size: 2rem;
    }

    .sidebar,
    .filter-bar {
        padding: 20px;
    }
}