/* ==========================================================
   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;
}

/* ==========================================================
   产品说明书风，清楚解释 ChatGPT 下载方式 - Product Manual Theme
   ========================================================== */

:root {
  --bg-page: #f8fafc;
  --bg-surface: #ffffff;
  --bg-sidebar: #f1f5f9;
  --bg-code: #0f172a;
  --primary: #0284c7;
  --primary-hover: #0369a1;
  --primary-light: #e0f2fe;
  --text-main: #1e293b;
  --text-muted: #64748b;
  --text-light: #94a3b8;
  --border-color: #cbd5e1;
  --border-light: #e2e8f0;
  --tech-blue: #2563eb;
  --alert-bg: #fef3c7;
  --alert-border: #f59e0b;
  --alert-text: #92400e;
  --step-bg: #0f172a;
  --step-text: #38bdf8;
  --font-base: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: Consolas, Monaco, "Courier New", monospace;
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.08), 0 2px 4px -1px rgba(0,0,0,0.04);
}

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

body {
  background-color: var(--bg-page);
  color: var(--text-main);
  font-family: var(--font-base);
  line-height: 1.65;
  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: #0f172a;
  color: #94a3b8;
  padding: 8px 0;
  font-size: 12.5px;
  border-bottom: 2px solid var(--primary);
}

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

.dec-badge {
  background: rgba(245, 158, 11, 0.2);
  color: #fde68a;
  border: 1px solid rgba(245, 158, 11, 0.5);
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  font-weight: 700;
  font-size: 11px;
  white-space: nowrap;
}

.dec-text {
  color: #cbd5e1;
  flex: 1;
  margin: 0;
}

/* 说明书风格 Header */
.site-header {
  background: var(--bg-surface);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: var(--shadow-sm);
}

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

.logo {
  display: flex;
  align-items: center;
  gap: 8px;
  text-decoration: none;
  font-size: 18px;
  font-weight: 800;
  color: #0f172a;
}

.logo-doc-icon {
  font-size: 20px;
}

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

.doc-ver-tag {
  background: var(--bg-sidebar);
  color: var(--text-muted);
  font-family: var(--font-mono);
  font-size: 11px;
  padding: 2px 6px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
}

.main-nav {
  display: flex;
  gap: 24px;
}

.nav-link {
  color: var(--text-muted);
  text-decoration: none;
  font-weight: 600;
  font-size: 14px;
  transition: all 0.2s ease;
  padding: 6px 0;
  position: relative;
}

.nav-link:hover, .nav-link.active {
  color: var(--primary);
}

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

.btn-manual-download {
  background: var(--primary);
  color: #ffffff;
  font-weight: 700;
  font-size: 13.5px;
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  text-decoration: none;
  border: 1px solid var(--primary-hover);
  transition: all 0.2s ease;
}

.btn-manual-download:hover {
  background: var(--primary-hover);
}

/* 说明书英雄区 (Hero) */
.manual-hero {
  background: #ffffff;
  border-bottom: 1px solid var(--border-color);
  padding: 44px 0 36px;
}

.manual-meta-strip {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 16px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-muted);
  flex-wrap: wrap;
}

.meta-chip {
  background: var(--bg-sidebar);
  border: 1px solid var(--border-color);
  padding: 3px 8px;
  border-radius: var(--radius-sm);
}

.hero-h1 {
  font-size: 36px;
  font-weight: 900;
  color: #0f172a;
  line-height: 1.3;
  margin-bottom: 14px;
  letter-spacing: -0.5px;
}

.hero-h1 .highlight {
  color: var(--primary);
  border-bottom: 3px solid var(--primary);
  padding-bottom: 2px;
}

.hero-desc {
  font-size: 16px;
  color: var(--text-muted);
  max-width: 860px;
  margin-bottom: 24px;
  line-height: 1.7;
}

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

.btn-cta-blue {
  background: var(--tech-blue);
  color: #fff;
  font-weight: 700;
  font-size: 15px;
  padding: 12px 26px;
  border-radius: var(--radius-sm);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  box-shadow: var(--shadow-sm);
  transition: all 0.2s ease;
}

.btn-cta-blue:hover {
  background: #1d4ed8;
  transform: translateY(-1px);
}

.btn-cta-outline {
  background: #fff;
  color: #0f172a;
  font-weight: 700;
  font-size: 15px;
  padding: 12px 24px;
  border-radius: var(--radius-sm);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  border: 1px solid var(--border-color);
  transition: all 0.2s ease;
}

.btn-cta-outline:hover {
  background: var(--bg-sidebar);
  border-color: #94a3b8;
}

/* 规格参数条 (Spec Bar) */
.spec-bar {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  background: var(--bg-sidebar);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 16px 20px;
}

.spec-item {
  border-right: 1px solid var(--border-color);
  padding-right: 12px;
}

.spec-item:last-child {
  border-right: none;
}

.spec-label {
  font-size: 12px;
  color: var(--text-muted);
  display: block;
  font-weight: 600;
  text-transform: uppercase;
}

.spec-val {
  font-size: 15px;
  font-weight: 800;
  color: #0f172a;
  font-family: var(--font-mono);
}

/* 说明书下载方式分步详解区 (核心设计亮点) */
.manual-download-section {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 32px;
  margin: 40px 0;
  box-shadow: var(--shadow-sm);
}

.download-steps-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  margin-top: 24px;
}

.step-card {
  background: var(--bg-page);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 20px;
  position: relative;
}

.step-num {
  position: absolute;
  top: -12px;
  left: 16px;
  background: var(--step-bg);
  color: var(--step-text);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 800;
  padding: 2px 8px;
  border-radius: var(--radius-sm);
}

.step-platform {
  font-size: 16px;
  font-weight: 800;
  color: #0f172a;
  margin: 8px 0 6px;
}

.step-desc {
  font-size: 13px;
  color: var(--text-muted);
  line-height: 1.5;
  margin-bottom: 12px;
}

.step-code {
  background: #ffffff;
  border: 1px dashed var(--border-color);
  padding: 6px 8px;
  font-size: 11.5px;
  color: var(--primary);
  font-family: var(--font-mono);
  border-radius: var(--radius-sm);
  word-break: break-all;
}

/* 六宫格功能模块区 */
.section {
  padding: 44px 0;
}

.section-header {
  margin-bottom: 28px;
}

.section-title {
  font-size: 24px;
  font-weight: 800;
  color: #0f172a;
  display: flex;
  align-items: center;
  gap: 8px;
}

.section-title::before {
  content: '§';
  color: var(--primary);
  font-family: var(--font-mono);
}

.section-subtitle {
  color: var(--text-muted);
  font-size: 14px;
  margin-top: 4px;
}

.grid-six {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.module-card {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 22px;
  transition: all 0.2s ease;
  box-shadow: var(--shadow-sm);
}

.module-card:hover {
  border-color: var(--primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.module-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
}

.module-icon {
  font-size: 24px;
}

.module-code {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--text-light);
  background: var(--bg-sidebar);
  padding: 1px 6px;
  border-radius: var(--radius-sm);
}

.module-title {
  font-size: 17px;
  font-weight: 700;
  color: #0f172a;
  margin-bottom: 8px;
}

.module-desc {
  font-size: 13.5px;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 14px;
}

.module-link {
  color: var(--primary);
  text-decoration: none;
  font-size: 13px;
  font-weight: 700;
  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: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 26px;
  box-shadow: var(--shadow-sm);
}

.panel-title {
  font-size: 19px;
  font-weight: 800;
  color: #0f172a;
  margin-bottom: 14px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.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(--primary);
  font-size: 10px;
  top: 4px;
}

.intro-list strong {
  color: #0f172a;
}

/* 热门教程表格 (说明书规范表格) */
.table-wrapper {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

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

.manual-table th {
  background: var(--bg-sidebar);
  color: #0f172a;
  font-weight: 700;
  font-size: 13.5px;
  padding: 13px 18px;
  border-bottom: 2px solid var(--border-color);
}

.manual-table td {
  padding: 14px 18px;
  color: var(--text-muted);
  font-size: 13.5px;
  border-bottom: 1px solid var(--border-light);
}

.manual-table tr:hover td {
  background: #f8fafc;
  color: var(--text-main);
}

.badge-tag {
  display: inline-block;
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  font-size: 11.5px;
  font-weight: 600;
}

.badge-easy {
  background: #dcfce7;
  color: #166534;
  border: 1px solid #bbf7d0;
}

.badge-medium {
  background: #fef3c7;
  color: #92400e;
  border: 1px solid #fde68a;
}

.badge-hard {
  background: #fee2e2;
  color: #991b1b;
  border: 1px solid #fecaca;
}

.tbl-link {
  color: var(--primary);
  text-decoration: none;
  font-weight: 700;
}

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

/* FAQ 常见问答模块 */
.faq-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.faq-item {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 20px;
  box-shadow: var(--shadow-sm);
}

.faq-q {
  font-size: 15.5px;
  font-weight: 800;
  color: #0f172a;
  margin-bottom: 8px;
  display: flex;
  align-items: flex-start;
  gap: 8px;
}

.faq-q-tag {
  background: var(--primary-light);
  color: var(--primary);
  font-size: 11px;
  padding: 1px 6px;
  border-radius: var(--radius-sm);
}

.faq-a {
  font-size: 13.5px;
  color: var(--text-muted);
  line-height: 1.6;
}

/* 延伸阅读与免责入口卡片 */
.extended-reading {
  background: var(--bg-sidebar);
  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: #0f172a;
  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: 40px 0 28px;
  background: #ffffff;
  border-bottom: 1px solid var(--border-color);
}

.page-title {
  font-size: 30px;
  font-weight: 900;
  color: #0f172a;
  margin-bottom: 8px;
}

.page-subtitle {
  color: var(--text-muted);
  font-size: 15px;
  max-width: 800px;
}

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

.article-content {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 36px;
  box-shadow: var(--shadow-sm);
  color: #334155;
  line-height: 1.8;
}

.article-content h2 {
  font-size: 22px;
  color: #0f172a;
  margin: 30px 0 14px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  gap: 8px;
}

.article-content h2::before {
  content: '§';
  color: var(--primary);
  font-family: var(--font-mono);
}

.article-content h3 {
  font-size: 17px;
  color: #0369a1;
  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: #0f172a;
}

.manual-callout {
  background: var(--alert-bg);
  border-left: 4px solid var(--alert-border);
  padding: 14px 18px;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin: 20px 0;
  color: var(--alert-text);
  font-size: 14px;
}

.code-box {
  background: var(--bg-code);
  border: 1px solid #1e293b;
  border-radius: var(--radius-sm);
  padding: 16px;
  font-family: var(--font-mono);
  font-size: 13.5px;
  color: #38bdf8;
  overflow-x: auto;
  margin: 18px 0;
}

/* 页脚 */
.site-footer {
  background: #0f172a;
  color: #94a3b8;
  padding: 50px 0 30px;
  margin-top: 50px;
  border-top: 3px solid var(--primary);
}

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

.footer-desc {
  color: #64748b;
  font-size: 13px;
  margin: 14px 0;
  line-height: 1.6;
  max-width: 400px;
}

.copyright {
  color: #475569;
  font-size: 12px;
}

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

.link-col h4 {
  color: #f8fafc;
  font-size: 14px;
  margin-bottom: 14px;
  font-weight: 700;
}

.link-col a {
  display: block;
  color: #94a3b8;
  text-decoration: none;
  font-size: 13px;
  margin-bottom: 8px;
  transition: all 0.2s ease;
}

.link-col a:hover {
  color: #38bdf8;
}

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

@media (max-width: 768px) {
  .main-nav {
    display: none;
  }
  .hero-h1 {
    font-size: 26px;
  }
  .download-steps-grid {
    grid-template-columns: 1fr;
  }
  .grid-six {
    grid-template-columns: 1fr;
  }
  .spec-bar {
    grid-template-columns: 1fr;
  }
  .footer-links {
    grid-template-columns: 1fr 1fr;
  }
}