/* === 纸飞机常见答疑 专属样式表 === */
:root {
    --accent-color: #0088cc;
    --text-dark: #0f172a;
    --text-muted: #64748b;
    --bg-aside: #f8fafc;
    --bg-main: #ffffff;
    --border-line: #e2e8f0;
    --faq-hover-bg: #fafafa;
    --hover-shadow: 0 10px 25px rgba(0,136,204,0.04);
    --radius-md: 12px;
    --radius-sm: 8px;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", sans-serif; color: var(--text-dark); background: var(--bg-main); line-height: 1.6; }

/* 侧边栏（与首页一致） */
.app-container { display: flex; min-height: 100vh; }
aside { width: 340px; background: var(--bg-aside); border-right: 1px solid var(--border-line); padding: 40px 30px; display: flex; flex-direction: column; justify-content: space-between; position: fixed; top: 0; bottom: 0; left: 0; z-index: 10; overflow-y: auto; }
.brand-section .logo-link { font-size: 24px; font-weight: 800; color: var(--accent-color); text-decoration: none; display: flex; align-items: center; gap: 8px; letter-spacing: -0.5px; }
.brand-section .site-intro { font-size: 13px; color: var(--text-muted); margin-top: 15px; text-align: justify; line-height: 1.7; }

.side-nav { margin-top: 40px; }
.side-nav ul { list-style: none; display: flex; flex-direction: column; gap: 6px; }
.side-nav a { display: flex; align-items: center; justify-content: space-between; text-decoration: none; color: #334155; font-weight: 600; font-size: 14px; padding: 10px 14px; border-radius: var(--radius-sm); transition: all 0.2s; }
.side-nav a:hover, .side-nav a.active { background: #fff; color: var(--accent-color); box-shadow: 0 4px 12px rgba(15,23,42,0.03); }
.side-nav a::after { content: "→"; opacity: 0; transform: translateX(-5px); transition: all 0.2s; font-weight: 400; }
.side-nav a:hover::after, .side-nav a.active::after { opacity: 1; transform: translateX(0); }

.aside-meta { font-size: 12px; color: #94a3b8; border-top: 1px solid var(--border-line); padding-top: 25px; }
.aside-meta a { color: var(--text-muted); text-decoration: none; display: inline-block; margin-bottom: 6px; transition: color 0.2s; }
.aside-meta a:hover { color: var(--accent-color); }
.aside-meta p { margin-top: 8px; line-height: 1.5; }

/* 主内容区域 */
main { margin-left: 340px; flex: 1; padding: 60px 80px; max-width: 1100px; }

.breadcrumb-trail { font-size: 13px; color: var(--text-muted); margin-bottom: 30px; }
.breadcrumb-trail a { color: var(--text-muted); text-decoration: none; }
.breadcrumb-trail a:hover { color: var(--accent-color); }

.view-header { margin-bottom: 30px; border-bottom: 1px solid var(--border-line); padding-bottom: 24px; }
.view-header h1 { font-size: 34px; font-weight: 800; letter-spacing: -1px; color: var(--text-dark); line-height: 1.3; margin-bottom: 12px; }
.view-header p { font-size: 16px; color: var(--text-muted); }

/* 问题分类快速导航（新增） */
.faq-category-bar { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; margin-bottom: 35px; padding: 16px 20px; background: #f8fafc; border-radius: var(--radius-md); border: 1px solid var(--border-line); }
.category-label { font-weight: 700; font-size: 14px; color: var(--text-dark); margin-right: 4px; }
.category-tag { background: #fff; color: #334155; text-decoration: none; padding: 6px 14px; border-radius: 20px; font-size: 13px; font-weight: 500; border: 1px solid var(--border-line); transition: all 0.2s; }
.category-tag:hover { background: var(--accent-color); color: #fff; border-color: var(--accent-color); }

/* 问题区块标题 */
.faq-section-title { font-size: 20px; font-weight: 800; color: var(--text-dark); margin: 35px 0 18px 0; display: flex; align-items: center; gap: 8px; }

/* 问题卡片矩阵 */
.faq-matrix { display: flex; flex-direction: column; gap: 24px; margin-bottom: 50px; }
.faq-node { border: 1px solid var(--border-line); border-radius: var(--radius-md); padding: 28px; transition: background 0.2s; }
.faq-node:hover { background: var(--faq-hover-bg); }
.faq-node h2 { font-size: 17px; font-weight: 800; color: var(--text-dark); margin-bottom: 14px; display: flex; align-items: flex-start; gap: 10px; line-height: 1.4; }
.faq-node h2::before { content: "Q."; color: var(--accent-color); font-style: italic; font-size: 20px; font-weight: 900; flex-shrink: 0; }

.faq-answer { color: #334155; font-size: 14.5px; line-height: 1.8; padding-left: 28px; }
.faq-answer p { margin-bottom: 12px; text-align: justify; }
.faq-answer ul { margin-left: 20px; margin-bottom: 12px; }
.faq-answer li { margin-bottom: 6px; }
.faq-answer code { background: #f1f5f9; padding: 2px 6px; border-radius: 4px; font-size: 0.9em; }
.faq-answer strong { color: var(--text-dark); }
.faq-answer a { color: var(--accent-color); text-decoration: none; font-weight: 500; }
.faq-answer a:hover { text-decoration: underline; }

/* 自检工具箱（新增创意板块） */
.self-check-toolkit { background: #f0f9ff; border: 1px solid #bae6fd; border-radius: var(--radius-md); padding: 30px; margin-bottom: 50px; }
.self-check-toolkit h2 { font-size: 22px; font-weight: 800; color: var(--text-dark); margin-bottom: 12px; display: flex; align-items: center; gap: 8px; }
.self-check-toolkit > p { font-size: 14px; color: #334155; margin-bottom: 24px; }
.check-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; margin-bottom: 20px; }
.check-item { display: flex; align-items: flex-start; gap: 12px; background: #fff; padding: 16px; border-radius: var(--radius-sm); border: 1px solid #e0f2fe; }
.check-icon { font-size: 20px; flex-shrink: 0; margin-top: 2px; }
.check-info h3 { font-size: 15px; font-weight: 700; color: var(--text-dark); margin-bottom: 4px; }
.check-info p { font-size: 13px; color: var(--text-muted); line-height: 1.5; margin: 0; }
.toolkit-footer { font-size: 14px; color: #475569; margin-top: 8px; }
.toolkit-footer a { color: var(--accent-color); text-decoration: none; font-weight: 600; }
.toolkit-footer a:hover { text-decoration: underline; }

/* 底部深层文本 */
.deep-seo-footer-text { border-top: 1px solid var(--border-line); padding-top: 50px; }
.deep-seo-footer-text h3 { font-size: 22px; font-weight: 800; color: var(--text-dark); margin-top: 35px; margin-bottom: 14px; }
.deep-seo-footer-text p { font-size: 15px; color: #334155; margin-bottom: 18px; text-align: justify; line-height: 1.8; }
.deep-seo-footer-text a { color: var(--accent-color); text-decoration: none; }
.deep-seo-footer-text a:hover { text-decoration: underline; }

/* 响应式设计 */
@media (max-width: 1024px) {
    aside { width: 260px; padding: 30px 20px; }
    main { margin-left: 260px; padding: 40px 40px; }
    .check-grid { grid-template-columns: 1fr; }
}
@media (max-width: 768px) {
    .app-container { flex-direction: column; }
    aside { width: 100%; position: relative; border-right: none; border-bottom: 1px solid var(--border-line); padding: 30px 20px; }
    .side-nav { margin-top: 20px; }
    .side-nav ul { flex-direction: row; flex-wrap: wrap; gap: 8px; }
    .side-nav a { padding: 6px 12px; font-size: 13px; }
    .side-nav a::after { display: none; }
    main { margin-left: 0; padding: 30px 20px; }
    .view-header h1 { font-size: 26px; }
    .faq-node { padding: 20px; }
    .faq-answer { padding-left: 0; }
    .faq-category-bar { flex-direction: column; align-items: flex-start; }
    .check-grid { grid-template-columns: 1fr; }
}