/* ==========================================================================
   力通电子 · Infineon distributor — 设计系统 (纯原生 CSS)
   主色 #0072CE | 中性灰 #F8F9FA | CTA #FF6B00
   ========================================================================== */

/* ---------- 1. 变量 Tokens ---------- */
:root {
  --color-primary: #0072CE;
  --color-primary-hover: #005A9E;
  --color-primary-dark: #003D73;
  --color-primary-light: #E6F2FC;
  --color-accent: #FF6B00;
  --color-accent-hover: #E65C00;
  --color-accent-light: #FFF1E6;

  --color-bg: #FFFFFF;
  --color-bg-gray: #F8F9FA;
  --color-bg-dark: #0B1B2B;
  --color-border: #E3E8EF;
  --color-text: #1F2933;
  --color-text-secondary: #52606D;
  --color-text-muted: #5A6672;

  --color-success: #1E8E3E;
  --color-success-light: #E6F4EA;
  --color-warning: #B26A00;
  --color-warning-light: #FFF4E5;
  --color-error: #C5221F;
  --color-info: #0B6BB2;

  --space-1: 4px;  --space-2: 8px;  --space-3: 12px; --space-4: 16px;
  --space-5: 20px; --space-6: 24px; --space-8: 32px; --space-10: 40px;
  --space-12: 48px; --space-16: 64px; --space-20: 80px;

  --radius-sm: 6px; --radius-md: 8px; --radius-lg: 12px; --radius-xl: 16px; --radius-full: 9999px;

  --shadow-sm: 0 1px 3px rgba(16, 24, 40, .06);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, .07);
  --shadow-lg: 0 10px 24px rgba(16, 24, 40, .10);
  --shadow-xl: 0 20px 40px rgba(16, 24, 40, .14);

  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue",
          "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", Arial, sans-serif;
  --font-mono: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;

  --text-xs: 12px; --text-sm: 14px; --text-base: 16px; --text-lg: 18px;
  --text-xl: 20px; --text-2xl: 24px; --text-3xl: 30px; --text-4xl: 38px; --text-5xl: 46px;

  --leading-tight: 1.25; --leading-normal: 1.6; --leading-relaxed: 1.8;
  --transition: 200ms ease;
  --container: 1319px;
  --header-h: 68px;
  --z-sticky: 100; --z-overlay: 300; --z-modal: 500;
}

/* ---------- 2. 重置与基础 ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font);
  font-size: var(--text-base);
  line-height: var(--leading-normal);
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
}
img, svg { max-width: 100%; display: block; }
a { color: var(--color-primary); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--color-primary-hover); }
h1, h2, h3, h4, h5 { margin: 0 0 var(--space-4); line-height: var(--leading-tight); color: var(--color-text); font-weight: 700; }
h1 { font-size: var(--text-4xl); }
h2 { font-size: var(--text-3xl); }
h3 { font-size: var(--text-xl); }
p { margin: 0 0 var(--space-4); }
ul, ol { margin: 0 0 var(--space-4); padding-left: 1.25em; }
:focus-visible { outline: 3px solid var(--color-primary); outline-offset: 2px; border-radius: 4px; }
.skip-link { position: absolute; left: -9999px; }
.skip-link:focus { left: 12px; top: 12px; z-index: 999; background: #fff; padding: 8px 16px; border-radius: var(--radius-md); box-shadow: var(--shadow-lg); }

/* ---------- 3. 布局 ---------- */
.container { width: 100%; max-width: var(--container); margin: 0 auto; padding: 0 var(--space-6); }
.container-narrow { max-width: 900px; }
.section { padding: var(--space-16) 0; }
.section-sm { padding: var(--space-10) 0; }
.section-gray { background: var(--color-bg-gray); }
.section-dark { background: linear-gradient(135deg, var(--color-primary-dark), var(--color-primary)); color: #fff; }
.section-dark h1, .section-dark h2, .section-dark h3 { color: #fff; }
.text-center { text-align: center; }
.section-head { max-width: 760px; margin: 0 auto var(--space-12); text-align: center; }
.section-head h2 { margin-bottom: var(--space-3); }
.section-subtitle { color: var(--color-text-secondary); font-size: var(--text-lg); margin: 0; }
.grid { display: grid; gap: var(--space-6); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
.grid-12 { display: grid; grid-template-columns: repeat(12, 1fr); gap: var(--space-6); }
.col-4 { grid-column: span 4; } .col-6 { grid-column: span 6; } .col-8 { grid-column: span 8; } .col-12 { grid-column: span 12; }
.flex { display: flex; } .flex-wrap { flex-wrap: wrap; } .items-center { align-items: center; }
.justify-between { justify-content: space-between; } .gap-2 { gap: var(--space-2); } .gap-4 { gap: var(--space-4); } .gap-6 { gap: var(--space-6); }

/* ---------- 4. 头部导航 ---------- */
.site-header {
  position: sticky; top: 0; z-index: var(--z-sticky);
  background: rgba(255, 255, 255, .92);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--color-border);
  transition: box-shadow var(--transition);
}
.site-header.scrolled { box-shadow: var(--shadow-md); }
.header-inner { display: flex; align-items: center; gap: var(--space-6); min-height: var(--header-h); }
.logo { display: flex; align-items: center; gap: var(--space-3); flex-shrink: 0; }
.logo svg { width: 44px; height: 44px; flex-shrink: 0; }
.logo-text { display: flex; flex-direction: column; line-height: 1.15; }
.logo-cn { font-size: 18px; font-weight: 800; color: var(--color-text); letter-spacing: .5px; }
.logo-en { font-size: 11px; color: var(--color-text-muted); text-transform: uppercase; letter-spacing: 1px; }
.logo-slogan { font-size: 11px; color: var(--color-primary); font-weight: 600; }
.main-nav { margin-left: auto; }
.nav-list { display: flex; align-items: center; gap: var(--space-2); list-style: none; margin: 0; padding: 0; }
.nav-link { display: block; padding: 8px 12px; font-size: 15px; font-weight: 500; color: var(--color-text); border-radius: var(--radius-md); }
.nav-link:hover, .nav-link.active { color: var(--color-primary); background: var(--color-primary-light); }
.header-actions { display: flex; align-items: center; gap: var(--space-3); }
.menu-toggle { display: none; flex-direction: column; gap: 5px; width: 44px; height: 44px; border: 1px solid var(--color-border); border-radius: var(--radius-md); background: #fff; align-items: center; justify-content: center; cursor: pointer; }
.menu-toggle span { display: block; width: 20px; height: 2px; background: var(--color-text); transition: var(--transition); }
.menu-toggle.active span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.menu-toggle.active span:nth-child(2) { opacity: 0; }
.menu-toggle.active span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* 产品中心下拉 */
.nav-item.has-dropdown { position: relative; }
.nav-dropdown { position: absolute; top: calc(100% + 8px); left: 0; min-width: 240px; background: #fff; border: 1px solid var(--color-border); border-radius: var(--radius-lg); box-shadow: var(--shadow-lg); padding: var(--space-2); list-style: none; margin: 0; opacity: 0; visibility: hidden; transform: translateY(6px); transition: var(--transition); }
.nav-item.has-dropdown:hover .nav-dropdown, .nav-item.has-dropdown:focus-within .nav-dropdown { opacity: 1; visibility: visible; transform: translateY(0); }
.nav-dropdown a { display: block; padding: 9px 12px; border-radius: var(--radius-sm); font-size: 14px; color: var(--color-text); }
.nav-dropdown a:hover { background: var(--color-bg-gray); color: var(--color-primary); }

/* ---------- 5. 面包屑 ---------- */
.breadcrumb { background: var(--color-bg-gray); border-bottom: 1px solid var(--color-border); }
.breadcrumb-list { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; list-style: none; margin: 0; padding: 12px 0; font-size: var(--text-sm); }
.breadcrumb-list li { display: flex; align-items: center; gap: 8px; color: var(--color-text-muted); }
.breadcrumb-list li:not(:last-child)::after { content: "/"; color: var(--color-border); }
.breadcrumb-list a { color: var(--color-text-secondary); }
.breadcrumb-list a:hover { color: var(--color-primary); }
.breadcrumb-list [aria-current] { color: var(--color-text); font-weight: 600; }

/* ---------- 6. Hero ---------- */
.hero { position: relative; overflow: hidden; color: #fff; padding: var(--space-20) 0; background: linear-gradient(135deg, #06233F 0%, #0A4C86 55%, #0072CE 100%); }
.hero-bg { position: absolute; inset: 0; opacity: .35; pointer-events: none; }
.hero .container { position: relative; z-index: 2; }
.hero-eyebrow { display: inline-flex; align-items: center; gap: 8px; background: rgba(255, 255, 255, .12); border: 1px solid rgba(255, 255, 255, .25); padding: 6px 16px; border-radius: var(--radius-full); font-size: var(--text-sm); margin-bottom: var(--space-5); }
.hero h1 { color: #fff; font-size: var(--text-5xl); margin-bottom: var(--space-4); }
.hero-subtitle { font-size: var(--text-xl); color: rgba(255, 255, 255, .92); max-width: 720px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: var(--space-4); margin-top: var(--space-8); }
.hero-stats { display: flex; flex-wrap: wrap; gap: var(--space-10); margin-top: var(--space-12); }
.hero-stat .num { font-size: var(--text-3xl); font-weight: 800; }
.hero-stat .label { font-size: var(--text-sm); color: rgba(255, 255, 255, .8); }
.hero-split { display: grid; grid-template-columns: 1.15fr .85fr; gap: var(--space-12); align-items: center; }
.hero-panel { background: rgba(255, 255, 255, .08); border: 1px solid rgba(255, 255, 255, .18); border-radius: var(--radius-xl); padding: var(--space-8); backdrop-filter: blur(6px); }
.hero-panel h3 { color: #fff; }

/* 页面 Banner（内页） */
.page-banner { background: linear-gradient(135deg, #06233F, #0072CE); color: #fff; padding: var(--space-12) 0; position: relative; overflow: hidden; }
.page-banner h1 { color: #fff; margin-bottom: var(--space-2); }
.page-banner p { color: rgba(255, 255, 255, .88); margin: 0; }
.page-banner .hero-bg { opacity: .25; }

/* 新闻详情全宽 Banner */
.news-banner { position: relative; min-height: 340px; display: flex; align-items: flex-end; background: linear-gradient(135deg, #06233F, #0A4C86); background-size: cover; background-position: center; color: #fff; }
.news-banner .container { position: relative; z-index: 2; padding-bottom: var(--space-10); padding-top: var(--space-10); }
.news-banner h1 { color: #fff; text-shadow: 0 2px 12px rgba(0, 0, 0, .5); max-width: 900px; }
.news-banner .meta { display: flex; flex-wrap: wrap; gap: var(--space-4); color: rgba(255, 255, 255, .9); font-size: var(--text-sm); text-shadow: 0 1px 6px rgba(0, 0, 0, .5); }

/* ---------- 7. 按钮 ---------- */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; min-height: 44px; padding: 12px 24px; font-size: 15px; font-weight: 600; border: 1px solid transparent; border-radius: var(--radius-md); cursor: pointer; transition: all var(--transition); text-align: center; line-height: 1; }
.btn:hover { box-shadow: var(--shadow-md); transform: translateY(-1px); }
.btn:active { transform: translateY(0); }
.btn-primary { background: var(--color-primary); color: #fff; }
.btn-primary:hover { background: var(--color-primary-hover); color: #fff; }
.btn-cta { background: var(--color-accent); color: #fff; }
.btn-cta:hover { background: var(--color-accent-hover); color: #fff; }
.btn-outline { background: transparent; color: var(--color-primary); border-color: var(--color-primary); }
.btn-outline:hover { background: var(--color-primary-light); }
.btn-white { background: #fff; color: var(--color-primary); }
.btn-white:hover { background: #f2f8ff; color: var(--color-primary-hover); }
.btn-outline-white { background: transparent; color: #fff; border-color: rgba(255, 255, 255, .7); }
.btn-outline-white:hover { background: rgba(255, 255, 255, .14); color: #fff; }
.btn-ghost { background: var(--color-bg-gray); color: var(--color-text); border-color: var(--color-border); }
.btn-sm { min-height: 38px; padding: 8px 16px; font-size: 14px; }
.btn-lg { min-height: 52px; padding: 14px 32px; font-size: 16px; }
.btn-block { width: 100%; }

/* ---------- 8. 卡片 ---------- */
.card { background: #fff; border: 1px solid var(--color-border); border-radius: var(--radius-lg); box-shadow: var(--shadow-md); overflow: hidden; transition: transform var(--transition), box-shadow var(--transition); }
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.card-link { display: block; color: inherit; }
.card-link:hover { color: inherit; }
.card-media { aspect-ratio: 16 / 9; background: var(--color-bg-gray); display: flex; align-items: center; justify-content: center; overflow: hidden; }
.card-media svg, .card-media img { width: 100%; height: 100%; object-fit: cover; }
.card-body { padding: var(--space-6); }
.card-body h3 { margin-bottom: var(--space-2); font-size: var(--text-lg); }
.card-body p { color: var(--color-text-secondary); font-size: var(--text-sm); margin-bottom: var(--space-3); }
.card-meta { display: flex; flex-wrap: wrap; gap: var(--space-3); font-size: var(--text-xs); color: var(--color-text-muted); }
.card-cta { color: var(--color-primary); font-weight: 600; font-size: var(--text-sm); }
.card:hover .card-cta { color: var(--color-accent); }
.card-flat { box-shadow: none; }
.card-flat:hover { transform: none; box-shadow: var(--shadow-md); }

/* 产品图标卡 */
.cat-card { text-align: center; }
.cat-card .cat-icon { width: 96px; height: 96px; margin: 0 auto var(--space-4); }
.cat-card .count { color: var(--color-primary); font-weight: 600; font-size: var(--text-sm); }

/* 通用列表页卡片网格 */
.card-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--space-6); }
.card-grid-2 { grid-template-columns: repeat(2, 1fr); }
.card-grid-4 { grid-template-columns: repeat(4, 1fr); }

/* ---------- 9. 核心优势 ---------- */
.feature-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--space-6); }
.feature { background: #fff; border: 1px solid var(--color-border); border-radius: var(--radius-lg); padding: var(--space-8) var(--space-6); text-align: center; box-shadow: var(--shadow-sm); transition: var(--transition); }
.feature:hover { box-shadow: var(--shadow-lg); transform: translateY(-4px); }
.feature .ico { width: 56px; height: 56px; margin: 0 auto var(--space-4); color: var(--color-primary); }
.feature h3 { font-size: var(--text-lg); }
.feature p { color: var(--color-text-secondary); font-size: var(--text-sm); margin: 0; }

/* 数字条 */
.stat-band { display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--space-6); text-align: center; }
.stat-band .num { font-size: var(--text-4xl); font-weight: 800; color: var(--color-primary); }
.stat-band .label { color: var(--color-text-secondary); }

/* ---------- 10. Tabs ---------- */
.tabs { border-bottom: 2px solid var(--color-border); display: flex; flex-wrap: wrap; gap: var(--space-2); margin-bottom: var(--space-8); }
.tab-btn { appearance: none; background: none; border: none; border-bottom: 3px solid transparent; padding: 12px 20px; font-size: 15px; font-weight: 600; color: var(--color-text-secondary); cursor: pointer; transition: var(--transition); margin-bottom: -2px; }
.tab-btn:hover { color: var(--color-primary); }
.tab-btn.active { color: var(--color-primary); border-bottom-color: var(--color-primary); }
.tab-panel { display: none; }
.tab-panel.active { display: block; animation: fadeIn .25s ease; }
.filter-chips { display: flex; flex-wrap: wrap; gap: var(--space-2); margin-bottom: var(--space-6); }
.chip { padding: 8px 16px; border: 1px solid var(--color-border); border-radius: var(--radius-full); font-size: var(--text-sm); color: var(--color-text-secondary); background: #fff; cursor: pointer; }
.chip:hover, .chip.active { border-color: var(--color-primary); color: var(--color-primary); background: var(--color-primary-light); }

/* ---------- 11. 表格 ---------- */
.table-wrap { overflow-x: auto; -webkit-overflow-scrolling: touch; border: 1px solid var(--color-border); border-radius: var(--radius-lg); }
table { width: 100%; border-collapse: collapse; font-size: var(--text-sm); }
th, td { padding: 12px 16px; text-align: left; border-bottom: 1px solid var(--color-border); white-space: nowrap; }
thead th { background: #EEF2F6; color: var(--color-text); font-weight: 700; position: sticky; top: 0; }
tbody tr:nth-child(even) { background: var(--color-bg-gray); }
tbody tr:hover { background: var(--color-primary-light); }
td a { font-weight: 600; }

/* 规格参数斑马纹表 */
.spec-table th { width: 220px; background: #EEF2F6; }
.spec-table td { white-space: normal; }

/* 动态筛选表 */
.filter-bar { display: flex; flex-wrap: wrap; gap: var(--space-3); margin-bottom: var(--space-5); align-items: flex-end; }
.filter-field { display: flex; flex-direction: column; gap: 4px; }
.filter-field label { font-size: var(--text-xs); color: var(--color-text-muted); font-weight: 600; }
.filter-field select { min-height: 40px; padding: 8px 12px; border: 1px solid var(--color-border); border-radius: var(--radius-md); background: #fff; font-size: var(--text-sm); color: var(--color-text); min-width: 140px; }
.filter-count { font-size: var(--text-sm); color: var(--color-text-muted); margin-left: auto; }
.filter-table th[data-sort] { cursor: pointer; user-select: none; }
.filter-table th[data-sort]::after { content: " ↕"; color: var(--color-text-muted); font-size: 11px; }
.table-empty { padding: var(--space-8); text-align: center; color: var(--color-text-muted); }

/* 库存标签 */
.badge { display: inline-flex; align-items: center; gap: 6px; padding: 4px 12px; border-radius: var(--radius-full); font-size: var(--text-xs); font-weight: 700; }
.badge-stock { background: var(--color-success-light); color: var(--color-success); }
.badge-inquiry { background: var(--color-warning-light); color: var(--color-warning); }
.badge-cat { background: var(--color-primary-light); color: var(--color-primary); }
.badge-tag { background: var(--color-bg-gray); color: var(--color-text-secondary); border: 1px solid var(--color-border); }

/* ---------- 12. 侧边栏 ---------- */
.layout-sidebar { display: grid; grid-template-columns: 1fr 300px; gap: var(--space-10); align-items: start; }
.layout-sidebar-left { grid-template-columns: 300px 1fr; }
.sidebar { display: flex; flex-direction: column; gap: var(--space-6); }
.sidebar-widget { background: #fff; border: 1px solid var(--color-border); border-radius: var(--radius-lg); padding: var(--space-6); box-shadow: var(--shadow-sm); }
.sidebar-widget h4 { font-size: var(--text-base); margin-bottom: var(--space-4); padding-bottom: var(--space-3); border-bottom: 1px solid var(--color-border); }
.sidebar-nav { list-style: none; margin: 0; padding: 0; }
.sidebar-nav li { margin-bottom: 2px; }
.sidebar-nav a { display: block; padding: 9px 12px; border-radius: var(--radius-md); font-size: var(--text-sm); color: var(--color-text-secondary); }
.sidebar-nav a:hover, .sidebar-nav a.active { background: var(--color-primary-light); color: var(--color-primary); font-weight: 600; }
.sticky-sidebar { position: sticky; top: calc(var(--header-h) + 20px); }
.toc { list-style: none; margin: 0; padding: 0; font-size: var(--text-sm); }
.toc a { display: block; padding: 6px 10px; border-left: 2px solid var(--color-border); color: var(--color-text-secondary); }
.toc a:hover, .toc a.active { border-left-color: var(--color-primary); color: var(--color-primary); background: var(--color-bg-gray); }

/* ---------- 13. 文章正文 ---------- */
.article { max-width: 800px; }
.article-content { font-size: 17px; line-height: 1.85; color: var(--color-text); }
.article-content > p { margin-bottom: 24px; }
.article-content h2 { font-size: var(--text-2xl); margin: 40px 0 16px; padding-left: 14px; border-left: 4px solid var(--color-primary); }
.article-content h3 { font-size: var(--text-lg); margin: 28px 0 12px; color: var(--color-text); }
.article-content ul, .article-content ol { margin-bottom: 24px; }
.article-content li { margin-bottom: 8px; }
.article-content blockquote { margin: 24px 0; padding: 16px 20px; border-left: 4px solid var(--color-accent); background: var(--color-accent-light); border-radius: 0 var(--radius-md) var(--radius-md) 0; color: var(--color-text-secondary); }
.article-content pre { background: #0F1B2A; color: #E6EDF3; padding: 18px 20px; border-radius: var(--radius-md); overflow-x: auto; font-family: var(--font-mono); font-size: 14px; line-height: 1.7; margin: 24px 0; }
.article-content code { font-family: var(--font-mono); font-size: .92em; background: var(--color-bg-gray); padding: 2px 6px; border-radius: 4px; }
.article-content pre code { background: none; padding: 0; color: inherit; }
.article-content img { border-radius: var(--radius-lg); margin: 24px 0; }
.article-content table { white-space: normal; }
.article-content figure { margin: 24px 0; }
.article-content figcaption { font-size: var(--text-sm); color: var(--color-text-muted); text-align: center; margin-top: 8px; }
.article-lead { font-size: var(--text-lg); color: var(--color-text-secondary); margin-bottom: var(--space-8); }

/* 作者栏 */
.author-box { display: flex; align-items: center; gap: var(--space-4); padding: var(--space-5); background: var(--color-bg-gray); border-radius: var(--radius-lg); margin: var(--space-8) 0; }
.author-avatar { width: 64px; height: 64px; border-radius: var(--radius-full); flex-shrink: 0; background: var(--color-primary-light); }
.author-box .name { font-weight: 700; }
.author-box .role { font-size: var(--text-sm); color: var(--color-text-secondary); }

/* 标签 */
.tag-list { display: flex; flex-wrap: wrap; gap: 8px; margin: var(--space-6) 0; }
.tag-pill { display: inline-flex; padding: 6px 14px; background: var(--color-bg-gray); border: 1px solid var(--color-border); border-radius: var(--radius-full); font-size: var(--text-xs); color: var(--color-text-secondary); }
.tag-pill:hover { background: var(--color-primary-light); color: var(--color-primary); border-color: var(--color-primary); }

/* 分享 */
.share-bar { display: flex; align-items: center; gap: var(--space-3); padding: var(--space-5) 0; border-top: 1px solid var(--color-border); border-bottom: 1px solid var(--color-border); margin: var(--space-8) 0; }
.share-bar .label { font-weight: 600; font-size: var(--text-sm); }
.share-btn { width: 40px; height: 40px; display: inline-flex; align-items: center; justify-content: center; border-radius: var(--radius-full); background: var(--color-bg-gray); border: 1px solid var(--color-border); cursor: pointer; }
.share-btn:hover { background: var(--color-primary-light); border-color: var(--color-primary); }

/* 相关文章 */
.related-list { list-style: none; margin: 0; padding: 0; }
.related-list li { padding: var(--space-3) 0; border-bottom: 1px dashed var(--color-border); }
.related-list li:last-child { border-bottom: none; }
.related-list a { font-weight: 500; font-size: var(--text-sm); }
.related-list .date { display: block; font-size: var(--text-xs); color: var(--color-text-muted); margin-top: 2px; }

/* ---------- 14. CTA 区块 ---------- */
.cta-band { background: linear-gradient(135deg, #0072CE, #06233F); color: #fff; border-radius: var(--radius-xl); padding: var(--space-12); text-align: center; position: relative; overflow: hidden; }
.cta-band h2 { color: #fff; }
.cta-band p { color: rgba(255, 255, 255, .9); max-width: 680px; margin: 0 auto var(--space-8); }
.cta-band .actions { display: flex; flex-wrap: wrap; gap: var(--space-4); justify-content: center; }
.cta-options { display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--space-4); margin-top: var(--space-8); }

/* ---------- 15. 表单 ---------- */
.form-group { margin-bottom: var(--space-5); }
.form-label { display: block; margin-bottom: 6px; font-size: var(--text-sm); font-weight: 600; color: var(--color-text); }
.form-label .req { color: var(--color-error); }
.form-input, .form-select, .form-textarea { width: 100%; min-height: 44px; padding: 10px 14px; font-size: var(--text-base); font-family: inherit; color: var(--color-text); background: #fff; border: 1px solid var(--color-border); border-radius: var(--radius-md); transition: var(--transition); }
.form-textarea { min-height: 120px; resize: vertical; }
.form-input:focus, .form-select:focus, .form-textarea:focus { border-color: var(--color-primary); box-shadow: 0 0 0 3px var(--color-primary-light); outline: none; }
.form-hint { font-size: var(--text-xs); color: var(--color-text-muted); margin-top: 4px; }

/* ---------- 16. 页脚 ---------- */
.site-footer { background: var(--color-bg-dark); color: #C3CDD8; padding: var(--space-16) 0 var(--space-6); margin-top: var(--space-16); }
.footer-grid { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1.2fr; gap: var(--space-10); }
.site-footer h4 { color: #fff; font-size: var(--text-base); margin-bottom: var(--space-5); }
.footer-brand .footer-logo { display: flex; align-items: center; gap: var(--space-3); color: #fff; font-weight: 700; margin-bottom: var(--space-4); }
.footer-brand .footer-logo svg { width: 40px; height: 40px; }
.footer-desc { font-size: var(--text-sm); color: #9AA7B4; line-height: 1.7; }
.footer-links { list-style: none; margin: 0; padding: 0; }
.footer-links li { margin-bottom: 10px; }
.footer-links a { color: #C3CDD8; font-size: var(--text-sm); }
.footer-links a:hover { color: #fff; }
.footer-contact { list-style: none; margin: 0; padding: 0; font-size: var(--text-sm); }
.footer-contact li { margin-bottom: 10px; color: #9AA7B4; }
.footer-bottom { display: flex; flex-wrap: wrap; gap: var(--space-4); justify-content: space-between; align-items: center; margin-top: var(--space-12); padding-top: var(--space-6); border-top: 1px solid rgba(255, 255, 255, .12); font-size: var(--text-xs); color: #8794A1; }
.footer-legal { display: flex; gap: var(--space-5); }
.footer-legal a { color: #8794A1; }

/* ---------- 17. 悬浮/提示 ---------- */
.back-to-top { position: fixed; right: 24px; bottom: 24px; width: 46px; height: 46px; border-radius: var(--radius-full); background: var(--color-primary); color: #fff; border: none; cursor: pointer; display: flex; align-items: center; justify-content: center; box-shadow: var(--shadow-lg); opacity: 0; visibility: hidden; transform: translateY(10px); transition: var(--transition); z-index: var(--z-sticky); }
.back-to-top.visible { opacity: 1; visibility: visible; transform: none; }
.toast { position: fixed; left: 50%; bottom: 40px; transform: translate(-50%, 20px); background: #111827; color: #fff; padding: 12px 24px; border-radius: var(--radius-md); box-shadow: var(--shadow-xl); opacity: 0; transition: var(--transition); z-index: var(--z-modal); }
.toast.show { opacity: 1; transform: translate(-50%, 0); }

/* QQ 悬浮 */
.qq-float { position: fixed; right: 24px; bottom: 84px; background: #12B7F5; color: #fff; border-radius: var(--radius-lg); padding: 12px 14px; box-shadow: var(--shadow-lg); font-size: var(--text-sm); text-align: center; z-index: var(--z-sticky); }
.qq-float strong { display: block; font-size: var(--text-base); }

/* ---------- 18. 通用工具 ---------- */
.mt-0 { margin-top: 0; } .mt-4 { margin-top: var(--space-4); } .mt-6 { margin-top: var(--space-6); } .mt-8 { margin-top: var(--space-8); }
.mb-0 { margin-bottom: 0; } .mb-4 { margin-bottom: var(--space-4); } .mb-6 { margin-bottom: var(--space-6); } .mb-8 { margin-bottom: var(--space-8); }
.muted { color: var(--color-text-muted); }
.secondary { color: var(--color-text-secondary); }
.small { font-size: var(--text-sm); }
.divider { height: 1px; background: var(--color-border); margin: var(--space-8) 0; border: none; }
.timeline-item { list-style: none; padding: 14px 0; border-bottom: 1px dashed var(--color-border); }
.timeline-item:last-child { border-bottom: none; }
.timeline-item strong { display: block; margin-bottom: 4px; }
.timeline-item .date { display: block; color: var(--color-text-secondary); font-size: var(--text-sm); }
.card-media .ico { width: 96px; height: 96px; }
.prose-img { border-radius: var(--radius-lg); border: 1px solid var(--color-border); }
.info-callout { background: var(--color-primary-light); border-left: 4px solid var(--color-primary); padding: var(--space-5) var(--space-6); border-radius: 0 var(--radius-md) var(--radius-md) 0; margin: var(--space-6) 0; }
.info-callout p:last-child { margin-bottom: 0; }
.ai-quote { background: var(--color-bg-gray); border: 1px dashed var(--color-primary); border-radius: var(--radius-lg); padding: var(--space-6); margin: var(--space-6) 0; }
.ai-quote::before { content: "供 AI 引用 / AI-Quotable"; display: block; font-size: var(--text-xs); font-weight: 700; color: var(--color-primary); margin-bottom: 8px; letter-spacing: .5px; }
.faq-item { border: 1px solid var(--color-border); border-radius: var(--radius-lg); padding: var(--space-5) var(--space-6); margin-bottom: var(--space-4); background: #fff; }
.faq-item h3 { font-size: var(--text-base); margin-bottom: var(--space-3); }
.faq-item p:last-child { margin-bottom: 0; }
.pager { display: flex; flex-wrap: wrap; gap: var(--space-3); justify-content: center; margin-top: var(--space-10); }

@keyframes fadeIn { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: none; } }

/* ---------- 19. 响应式 ---------- */
@media (max-width: 1199px) {
  h1 { font-size: var(--text-3xl); }
  .hero h1 { font-size: var(--text-4xl); }
  .feature-grid, .grid-4, .stat-band, .cta-options { grid-template-columns: repeat(2, 1fr); }
  .card-grid, .card-grid-4 { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .layout-sidebar, .layout-sidebar-left { grid-template-columns: 1fr; }
  .hero-split { grid-template-columns: 1fr; }
}

@media (max-width: 767px) {
  :root { --text-4xl: 30px; --text-5xl: 34px; --text-3xl: 24px; }
  .container { padding: 0 var(--space-4); }
  .section { padding: var(--space-12) 0; }
  .menu-toggle { display: flex; }
  .main-nav { position: fixed; top: var(--header-h); left: 0; right: 0; background: #fff; border-bottom: 1px solid var(--color-border); box-shadow: var(--shadow-lg); max-height: calc(100vh - var(--header-h)); overflow-y: auto; transform: translateY(-120%); transition: transform var(--transition); }
  .main-nav.active { transform: translateY(0); }
  .nav-list { flex-direction: column; align-items: stretch; padding: var(--space-4); gap: 2px; }
  .nav-link { padding: 14px 12px; }
  .nav-dropdown { position: static; opacity: 1; visibility: visible; transform: none; box-shadow: none; border: none; padding-left: var(--space-4); }
  .header-actions .btn { display: none; }
  .grid-2, .grid-3, .grid-4, .feature-grid, .stat-band, .cta-options, .card-grid, .card-grid-2, .card-grid-4 { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; gap: var(--space-6); }
  .hero { padding: var(--space-12) 0; }
  .hero-stats { gap: var(--space-6); }
  .hero-actions .btn { width: 100%; }
  .cta-band { padding: var(--space-8) var(--space-5); }
  .qq-float { display: none; }
  .grid-12 { grid-template-columns: 1fr; }
  .col-4, .col-6, .col-8, .col-12 { grid-column: span 1; }
  .tabs { flex-wrap: nowrap; overflow-x: auto; }
  .tab-btn { white-space: nowrap; }
  .author-box { flex-direction: column; text-align: center; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: .001ms !important; transition-duration: .001ms !important; scroll-behavior: auto !important; }
}