/* ==========================================================
   上线性能与顺滑度增强引擎 (Smoothness & Performance Optimization)
   ========================================================== */
html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

body {
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
  width: 100%;
}

*, *::before, *::after {
  box-sizing: border-box;
}

/* 硬件加速与流畅悬停 */
a, button, .media-news-card, .btn-media-primary, .btn-media-secondary, .faq-card, .intro-panel {
  -webkit-backface-visibility: hidden;
  backface-visibility: hidden;
  transform: translateZ(0);
}

/* 移动端平滑滚动与防抖 */
.table-wrapper, .table-container, .code-box, pre {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
}

/* 媒体图片防溢出与自适应 */
img, svg, video, canvas {
  max-width: 100%;
  height: auto;
  display: block;
}

/* 消除点击高亮延迟 */
a, button, input, select, textarea {
  -webkit-tap-highlight-color: transparent;
}

/* ==========================================================
   问答社区风格，FAQ 和热门问题优先 - Q&A Community Theme
   ========================================================== */

:root {
  --bg-body: #0b0f19;
  --bg-surface: #111827;
  --bg-card: #1f293d;
  --bg-card-hover: #28354f;
  --bg-card-alt: #162032;
  --primary: #3b82f6;
  --primary-hover: #60a5fa;
  --primary-light: rgba(59, 130, 246, 0.15);
  --accent: #10b981;
  --accent-light: rgba(16, 185, 129, 0.15);
  --warning: #f59e0b;
  --border-color: #334155;
  --border-subtle: rgba(255, 255, 255, 0.08);
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --text-dim: #64748b;
  --font-base: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --transition: all 0.25s ease;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
}

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

body {
  background-color: var(--bg-body);
  background-image: 
    radial-gradient(circle at 50% 0%, rgba(59, 130, 246, 0.08) 0%, transparent 50%),
    radial-gradient(circle at 80% 40%, rgba(16, 185, 129, 0.05) 0%, transparent 40%);
  background-attachment: fixed;
  color: var(--text-main);
  font-family: var(--font-base);
  line-height: 1.6;
  font-size: 15px;
  -webkit-font-smoothing: antialiased;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* 顶部独立声明条 */
.top-declaration-bar {
  background: #080c14;
  border-bottom: 1px solid var(--border-color);
  padding: 8px 0;
  font-size: 12.5px;
}

.dec-content {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

.dec-badge {
  background: rgba(245, 158, 11, 0.15);
  color: #fbbf24;
  border: 1px solid rgba(245, 158, 11, 0.3);
  padding: 2px 8px;
  border-radius: 4px;
  font-weight: 600;
  white-space: nowrap;
}

.dec-text {
  color: var(--text-muted);
  flex: 1;
  margin: 0;
}

/* 社区 Header */
.site-header {
  background: rgba(17, 24, 39, 0.88);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
  gap: 20px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  font-size: 18px;
  font-weight: 800;
  color: #fff;
  white-space: nowrap;
}

.logo-badge {
  background: var(--primary);
  color: #fff;
  font-size: 11px;
  font-weight: 800;
  padding: 3px 7px;
  border-radius: 4px;
  letter-spacing: 0.5px;
}

.accent-text {
  color: var(--primary-hover);
}

.header-search-mock {
  flex: 1;
  max-width: 380px;
  position: relative;
  display: flex;
  align-items: center;
}

.search-icon {
  position: absolute;
  left: 12px;
  font-size: 14px;
  color: var(--text-dim);
}

.search-input {
  width: 100%;
  background: var(--bg-card-alt);
  border: 1px solid var(--border-color);
  border-radius: 20px;
  padding: 7px 16px 7px 34px;
  color: var(--text-main);
  font-size: 13px;
  outline: none;
  transition: var(--transition);
}

.search-input:focus {
  border-color: var(--primary);
  background: #1e293b;
}

.main-nav {
  display: flex;
  gap: 22px;
}

.nav-link {
  color: var(--text-muted);
  text-decoration: none;
  font-weight: 500;
  font-size: 14px;
  transition: var(--transition);
  padding: 6px 0;
  position: relative;
}

.nav-link:hover, .nav-link.active {
  color: #fff;
}

.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 100%;
  height: 2px;
  background: var(--primary);
  border-radius: 2px;
}

.btn-ask {
  background: var(--primary);
  color: #fff;
  text-decoration: none;
  font-size: 13.5px;
  font-weight: 600;
  padding: 8px 18px;
  border-radius: 20px;
  transition: var(--transition);
  white-space: nowrap;
}

.btn-ask:hover {
  background: var(--primary-hover);
  box-shadow: 0 4px 12px rgba(59, 130, 246, 0.4);
}

/* 首页社区 Hero 区域 */
.community-hero {
  padding: 48px 0 36px;
  background: linear-gradient(180deg, rgba(31, 41, 61, 0.5) 0%, transparent 100%);
  border-bottom: 1px solid var(--border-subtle);
}

.hero-stats-banner {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  background: rgba(59, 130, 246, 0.1);
  border: 1px solid rgba(59, 130, 246, 0.25);
  padding: 5px 14px;
  border-radius: 20px;
  color: var(--primary-hover);
  font-size: 12.5px;
  font-weight: 600;
  margin-bottom: 18px;
}

.hero-h1 {
  font-size: 38px;
  font-weight: 900;
  color: #fff;
  line-height: 1.25;
  margin-bottom: 16px;
}

.hero-h1 .highlight {
  color: var(--primary-hover);
  background: linear-gradient(90deg, #60a5fa, #34d399);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-desc {
  font-size: 16px;
  color: var(--text-muted);
  max-width: 820px;
  line-height: 1.7;
  margin-bottom: 28px;
}

.hero-cta-group {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 30px;
}

.btn-cta-primary {
  background: #2563eb;
  color: #fff;
  font-weight: 700;
  font-size: 15px;
  padding: 12px 28px;
  border-radius: 8px;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  transition: var(--transition);
  box-shadow: 0 4px 14px rgba(37, 99, 235, 0.35);
}

.btn-cta-primary:hover {
  background: #3b82f6;
  transform: translateY(-2px);
}

.btn-cta-secondary {
  background: var(--bg-card);
  color: #f1f5f9;
  font-weight: 600;
  font-size: 15px;
  padding: 12px 26px;
  border-radius: 8px;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  border: 1px solid var(--border-color);
  transition: var(--transition);
}

.btn-cta-secondary:hover {
  background: var(--bg-card-hover);
  border-color: var(--primary);
  transform: translateY(-2px);
}

.community-metrics-bar {
  display: flex;
  gap: 30px;
  padding-top: 20px;
  border-top: 1px solid var(--border-subtle);
  flex-wrap: wrap;
}

.c-metric {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13.5px;
  color: var(--text-muted);
}

.c-metric-num {
  font-weight: 800;
  color: #fff;
  font-size: 16px;
}

/* 优先展示：社区精选置顶 FAQ 问答列表 (热门问题优先) */
.section {
  padding: 50px 0;
}

.section-header-flex {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  margin-bottom: 30px;
  flex-wrap: wrap;
  gap: 16px;
}

.section-title {
  font-size: 26px;
  font-weight: 800;
  color: #fff;
  display: flex;
  align-items: center;
  gap: 10px;
}

.section-tag {
  color: var(--primary);
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  display: block;
  margin-bottom: 4px;
}

.qa-tab-filters {
  display: flex;
  gap: 8px;
}

.qa-filter-btn {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-muted);
  padding: 6px 14px;
  border-radius: 20px;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  text-decoration: none;
  transition: var(--transition);
}

.qa-filter-btn.active, .qa-filter-btn:hover {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

/* 问答列表项样式 */
.qa-stream {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.qa-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 22px 24px;
  display: grid;
  grid-template-columns: 70px 1fr;
  gap: 20px;
  transition: var(--transition);
}

.qa-card:hover {
  border-color: var(--primary);
  background: var(--bg-card-alt);
  box-shadow: 0 6px 20px rgba(0,0,0,0.3);
}

.qa-vote-box {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background: rgba(255, 255, 255, 0.03);
  border-radius: var(--radius-sm);
  padding: 10px 6px;
  text-align: center;
  border: 1px solid var(--border-subtle);
}

.vote-num {
  font-size: 16px;
  font-weight: 800;
  color: #fff;
}

.vote-label {
  font-size: 11px;
  color: var(--text-dim);
}

.qa-badge-solved {
  margin-top: 6px;
  font-size: 10px;
  background: var(--accent-light);
  color: #34d399;
  border: 1px solid rgba(16, 185, 129, 0.3);
  padding: 1px 4px;
  border-radius: 3px;
  font-weight: 600;
}

.qa-main {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.qa-title-wrap {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.qa-tag-badge {
  font-size: 11px;
  padding: 2px 8px;
  border-radius: 4px;
  font-weight: 600;
  background: rgba(59, 130, 246, 0.15);
  color: #93c5fd;
  border: 1px solid rgba(59, 130, 246, 0.3);
}

.qa-title-link {
  font-size: 17px;
  font-weight: 700;
  color: #f8fafc;
  text-decoration: none;
  transition: var(--transition);
}

.qa-title-link:hover {
  color: var(--primary-hover);
}

.qa-snippet {
  color: var(--text-muted);
  font-size: 14px;
  line-height: 1.6;
}

.qa-footer-meta {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-top: 6px;
  font-size: 12.5px;
  color: var(--text-dim);
  flex-wrap: wrap;
}

.author-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--text-muted);
}

.verified-icon {
  color: #10b981;
}

/* 六宫格功能模块区 (社区专题库) */
.grid-six {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.module-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 24px;
  transition: var(--transition);
  position: relative;
}

.module-card:hover {
  transform: translateY(-3px);
  border-color: var(--primary);
  background: var(--bg-card);
}

.module-icon {
  font-size: 28px;
  margin-bottom: 12px;
  display: inline-block;
}

.module-title {
  font-size: 18px;
  font-weight: 700;
  color: #fff;
  margin-bottom: 10px;
}

.module-desc {
  color: var(--text-muted);
  font-size: 13.5px;
  line-height: 1.6;
  margin-bottom: 16px;
}

.module-link {
  color: var(--primary-hover);
  text-decoration: none;
  font-size: 13px;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.module-link:hover {
  text-decoration: underline;
}

/* 正文介绍区：“教程中心”与“我们提供什么” */
.intro-container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

.intro-panel {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 28px;
}

.panel-title {
  font-size: 20px;
  font-weight: 800;
  color: #fff;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 10px;
}

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

.intro-list li {
  position: relative;
  padding-left: 20px;
  margin-bottom: 12px;
  color: var(--text-muted);
  font-size: 14px;
}

.intro-list li::before {
  content: '✓';
  position: absolute;
  left: 0;
  color: var(--accent);
  font-weight: 800;
}

.intro-list strong {
  color: #fff;
}

/* 热门教程表格 */
.table-wrapper {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.community-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
}

.community-table th {
  background: #162032;
  color: #e2e8f0;
  font-weight: 700;
  font-size: 13.5px;
  padding: 14px 18px;
  border-bottom: 1px solid var(--border-color);
}

.community-table td {
  padding: 15px 18px;
  color: var(--text-muted);
  font-size: 13.5px;
  border-bottom: 1px solid var(--border-subtle);
}

.community-table tr:hover td {
  background: rgba(59, 130, 246, 0.04);
  color: var(--text-main);
}

.badge-tag {
  display: inline-block;
  padding: 3px 8px;
  border-radius: 4px;
  font-size: 11.5px;
  font-weight: 600;
}

.badge-easy {
  background: rgba(16, 185, 129, 0.15);
  color: #34d399;
  border: 1px solid rgba(16, 185, 129, 0.3);
}

.badge-medium {
  background: rgba(245, 158, 11, 0.15);
  color: #fbbf24;
  border: 1px solid rgba(245, 158, 11, 0.3);
}

.badge-hard {
  background: rgba(239, 68, 68, 0.15);
  color: #f87171;
  border: 1px solid rgba(239, 68, 68, 0.3);
}

.tbl-link {
  color: var(--primary-hover);
  text-decoration: none;
  font-weight: 600;
}

.tbl-link:hover {
  text-decoration: underline;
}

/* 延伸阅读与免责入口卡片 */
.extended-reading {
  background: linear-gradient(135deg, #162032 0%, #1e293b 100%);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 24px 28px;
  margin-top: 30px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 20px;
}

.reading-info h4 {
  font-size: 17px;
  color: #fff;
  margin-bottom: 4px;
}

.reading-info p {
  color: var(--text-muted);
  font-size: 13.5px;
}

.reading-actions {
  display: flex;
  gap: 12px;
}

/* 子页面通用内容布局 */
.page-hero {
  padding: 44px 0 30px;
  background: #111827;
  border-bottom: 1px solid var(--border-color);
}

.page-title {
  font-size: 30px;
  font-weight: 900;
  color: #fff;
  margin-bottom: 10px;
}

.page-subtitle {
  color: var(--text-muted);
  font-size: 15px;
  max-width: 750px;
}

.content-section {
  padding: 40px 0;
}

.article-content {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 36px;
  color: #cbd5e1;
  line-height: 1.8;
}

.article-content h2 {
  font-size: 22px;
  color: #fff;
  margin: 30px 0 14px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  gap: 8px;
}

.article-content h2::before {
  content: '#';
  color: var(--primary);
}

.article-content h3 {
  font-size: 17px;
  color: #93c5fd;
  margin: 20px 0 10px;
}

.article-content p {
  margin-bottom: 14px;
}

.article-content ul, .article-content ol {
  margin-bottom: 18px;
  padding-left: 24px;
}

.article-content li {
  margin-bottom: 6px;
}

.article-content strong {
  color: #fff;
}

.callout-box {
  background: rgba(59, 130, 246, 0.08);
  border-left: 4px solid var(--primary);
  padding: 14px 18px;
  border-radius: 0 6px 6px 0;
  margin: 20px 0;
  color: #e2e8f0;
}

.code-box {
  background: #090d16;
  border: 1px solid var(--border-color);
  border-radius: 6px;
  padding: 16px;
  font-family: Consolas, Monaco, monospace;
  font-size: 13.5px;
  color: #93c5fd;
  overflow-x: auto;
  margin: 18px 0;
}

/* 页脚 */
.site-footer {
  background: #080c14;
  border-top: 1px solid var(--border-color);
  padding: 50px 0 30px;
  margin-top: 50px;
}

.footer-inner {
  display: grid;
  grid-template-columns: 1.5fr 2fr;
  gap: 40px;
  margin-bottom: 30px;
}

.footer-desc {
  color: var(--text-dim);
  font-size: 13px;
  margin: 14px 0;
  line-height: 1.6;
  max-width: 400px;
}

.copyright {
  color: var(--text-dim);
  font-size: 12px;
}

.footer-links {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.link-col h4 {
  color: #f1f5f9;
  font-size: 14px;
  margin-bottom: 14px;
  font-weight: 700;
}

.link-col a {
  display: block;
  color: var(--text-muted);
  text-decoration: none;
  font-size: 13px;
  margin-bottom: 8px;
  transition: var(--transition);
}

.link-col a:hover {
  color: var(--primary-hover);
}

/* 响应式 */
@media (max-width: 992px) {
  .grid-six {
    grid-template-columns: repeat(2, 1fr);
  }
  .intro-container {
    grid-template-columns: 1fr;
  }
  .footer-inner {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .main-nav, .header-search-mock {
    display: none;
  }
  .hero-h1 {
    font-size: 26px;
  }
  .grid-six {
    grid-template-columns: 1fr;
  }
  .qa-card {
    grid-template-columns: 1fr;
    gap: 12px;
  }
  .qa-vote-box {
    flex-direction: row;
    justify-content: flex-start;
    gap: 12px;
    padding: 6px 12px;
  }
  .footer-links {
    grid-template-columns: 1fr 1fr;
  }
}