* {
    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-detail-page {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

/* Breadcrumb */
.breadcrumb {
    background: white;
    border-radius: 8px;
    padding: 15px 20px;
    margin-bottom: 20px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}

    .breadcrumb a {
        color: #1890ff;
        text-decoration: none;
        margin-right: 8px;
    }

        .breadcrumb a:hover {
            text-decoration: underline;
        }

.breadcrumb-separator {
    color: #999;
    margin: 0 8px;
}

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

/* Sidebar */
.sidebar {
    width: 250px;
    background: white;
    border-radius: 12px;
    padding: 25px;
    box-shadow: 0 2px 12px rgba(0,0,0,0.08);
    height: fit-content;
    position: sticky;
    top: 20px;
}

.sidebar-title {
    font-size: 1.1rem;
    font-weight: 600;
    color: #333;
    margin-bottom: 15px;
    padding-bottom: 8px;
    border-bottom: 2px solid #1890ff;
}

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

.toc-item {
    margin-bottom: 6px;
}

.toc-link {
    display: block;
    padding: 8px 12px;
    color: #666;
    text-decoration: none;
    border-radius: 4px;
    font-size: 0.9rem;
    transition: all 0.3s ease;
}

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

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

/* Article Header */
.article-header {
    background: white;
    border-radius: 12px;
    padding: 30px;
    margin-bottom: 20px;
    box-shadow: 0 2px 12px rgba(0,0,0,0.08);
}

.article-category {
    display: inline-block;
    background: #f0f8ff;
    color: #1890ff;
    padding: 6px 16px;
    border-radius: 16px;
    font-size: 0.9rem;
    margin-bottom: 15px;
}

.article-title {
    font-size: 2rem;
    font-weight: 700;
    color: #333;
    margin-bottom: 15px;
    line-height: 1.3;
}

.article-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 15px;
    color: #666;
    font-size: 0.9rem;
}

.meta-left {
    display: flex;
    align-items: center;
    gap: 20px;
}

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

.meta-right {
    display: flex;
    align-items: center;
    gap: 15px;
}

.action-button {
    padding: 8px 16px;
    border: 1px solid #d9d9d9;
    background: white;
    color: #666;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
    font-size: 0.9rem;
}

    .action-button:hover {
        background: #1890ff;
        color: white;
        border-color: #1890ff;
    }

/* Article Content */
.article-content {
    background: white;
    border-radius: 12px;
    padding: 40px;
    margin-bottom: 20px;
    box-shadow: 0 2px 12px rgba(0,0,0,0.08);
}

.content-section {
    margin-bottom: 30px;
}

    .content-section:last-child {
        margin-bottom: 0;
    }

.section-title {
    font-size: 1.4rem;
    font-weight: 600;
    color: #333;
    margin-bottom: 15px;
    padding-bottom: 8px;
    border-bottom: 2px solid #f0f0f0;
}

.content-text {
    color: #555;
    line-height: 1.8;
    margin-bottom: 15px;
}

    .content-text p {
        margin-bottom: 15px;
    }

    .content-text ul,
    .content-text ol {
        margin: 15px 0;
        padding-left: 25px;
    }

    .content-text li {
        margin-bottom: 8px;
    }

.code-block {
    background: #f8f9fa;
    border: 1px solid #e9ecef;
    border-radius: 6px;
    padding: 15px;
    margin: 15px 0;
    font-family: 'Courier New', monospace;
    font-size: 0.9rem;
    overflow-x: auto;
}

.highlight-box {
    background: #fff7e6;
    border: 1px solid #ffd591;
    border-radius: 6px;
    padding: 15px;
    margin: 15px 0;
}

    .highlight-box.warning {
        background: #fff2e8;
        border-color: #ffb366;
    }

    .highlight-box.success {
        background: #f6ffed;
        border-color: #b7eb8f;
    }

/* Related Articles */
.related-articles {
    background: white;
    border-radius: 12px;
    padding: 30px;
    margin-bottom: 20px;
    box-shadow: 0 2px 12px rgba(0,0,0,0.08);
}

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

.related-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
}

.related-card {
    padding: 20px;
    border: 1px solid #f0f0f0;
    border-radius: 8px;
    transition: all 0.3s ease;
    cursor: pointer;
}

    .related-card:hover {
        border-color: #1890ff;
        box-shadow: 0 4px 12px rgba(24, 144, 255, 0.1);
    }

.related-card-title {
    font-size: 1rem;
    font-weight: 600;
    color: #333;
    margin-bottom: 8px;
    line-height: 1.4;
}

.related-card-excerpt {
    color: #666;
    font-size: 0.9rem;
    line-height: 1.5;
}

/* Feedback Section */
.feedback-section {
    background: white;
    border-radius: 12px;
    padding: 30px;
    box-shadow: 0 2px 12px rgba(0,0,0,0.08);
}

.feedback-title {
    font-size: 1.3rem;
    font-weight: 600;
    color: #333;
    margin-bottom: 20px;
    text-align: center;
}

.feedback-buttons {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-bottom: 20px;
}

.feedback-button {
    padding: 12px 24px;
    border: 2px solid #d9d9d9;
    background: white;
    color: #666;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 1rem;
    display: flex;
    align-items: center;
    gap: 8px;
}

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

    .feedback-button.helpful.active {
        background: #52c41a;
        border-color: #52c41a;
    }

    .feedback-button.not-helpful.active {
        background: #ff4d4f;
        border-color: #ff4d4f;
    }

.feedback-form {
    margin-top: 20px;
    padding-top: 20px;
    border-top: 1px solid #f0f0f0;
}

.feedback-textarea {
    width: 100%;
    min-height: 100px;
    padding: 12px;
    border: 1px solid #d9d9d9;
    border-radius: 6px;
    resize: vertical;
    font-family: inherit;
    font-size: 0.9rem;
}

.feedback-submit {
    margin-top: 15px;
    padding: 10px 20px;
    background: #1890ff;
    color: white;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: background 0.3s ease;
}

    .feedback-submit:hover {
        background: #40a9ff;
    }

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

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

    .article-meta {
        flex-direction: column;
        align-items: flex-start;
    }

    .meta-right {
        width: 100%;
        justify-content: flex-start;
    }
}

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

    .article-header,
    .article-content,
    .related-articles,
    .feedback-section {
        padding: 20px;
    }

    .article-title {
        font-size: 1.5rem;
    }

    .feedback-buttons {
        flex-direction: column;
        align-items: center;
    }

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