/* ==========================================================================
   Cyberwisdom Group — Design System V2
   --------------------------------------------------------------------------
   方向：美国企业级科技集团（US enterprise technology group）
   参考：absorbai.com 的成熟企业语言 —— 深靛主色、克制留白、清晰层级、
         强 CTA 转化、宏大呼吸感的企业排版。
   原创：色板、字阶、栅格、圆角、阴影、组件形态均为 Cyberwisdom 自有表达。

   与 V1 的差异
   ------------
   1. 主色从「亮蓝 + 青」转为「深靛 + 单一品牌蓝」，去掉双引擎撞色 —— 本轮
      只做数字学习业务，双色语义造成视觉噪音。
   2. 排版尺度放大（h1 最高 4.15rem），行高更松，段落最大宽度受控。
   3. 圆角统一为 4px 系统（--r-xs 4 / --r-sm 8 / --r-md 14 / --r-lg 20 /
      --r-xl 28 / --r-pill 999），按钮从「药丸」改为「企业级方角 + 轻圆角」。
   4. 阴影从彩色发光改为中性分层（--sh-1..4），更接近 US enterprise SaaS。
   5. 新增组件：mega menu、use-case tabs、feature grid、logo wall、
      evidence band、终局 CTA、打印样式。
   6. 焦点样式全局可见（--focus），满足 WCAG 2.2 AA 键盘导航。
   ========================================================================== */

/* ==========================================================================
   1. 设计令牌
   ========================================================================== */
:root {
  /* ---- 品牌主色：深靛（企业稳重） ---- */
  --brand-900: #0A1733;
  --brand-800: #0E2047;
  --brand-700: #143060;
  --brand-600: #1B4183;
  --brand-500: #2358AC;
  --brand-400: #2569E0;
  --brand-300: #6BA3FF;
  --brand-200: #A8C8FF;
  --brand-100: #DCE9FF;
  --brand-50:  #F1F6FF;

  /* ---- 中性色阶（带一丝冷调，避免死灰） ---- */
  --ink-950: #060B18;
  --ink-900: #0A1224;
  --ink-800: #101A33;
  --ink-700: #17234A;
  --ink-600: #223059;
  --ink-500: #33406B;

  --paper: #FFFFFF;
  --paper-2: #F5F7FB;
  --paper-3: #EBEFF7;
  --paper-4: #E1E7F2;

  /* ---- 文字 ---- */
  --text-hi: #0A1224;
  --text-body: #39455F;
  --text-mute: #5A667E;
  --text-faint: #5F6B84;
  --text-on-dark: #FFFFFF;
  --text-on-dark-2: rgba(255, 255, 255, 0.74);
  --text-on-dark-3: rgba(255, 255, 255, 0.52);

  /* ---- 线条 ---- */
  --line: rgba(10, 18, 36, 0.10);
  --line-strong: rgba(10, 18, 36, 0.20);
  --line-dark: rgba(255, 255, 255, 0.12);
  --line-dark-strong: rgba(255, 255, 255, 0.28);

  /* ---- 语义状态 ---- */
  --success: #0E8A5F;
  --success-bg: #E6F5EE;
  --warning: #B4690E;
  --warning-bg: #FDF3E3;
  --error: #C6382F;
  --error-bg: #FCEDEC;
  --focus: #2569E0;

  /* ---- 强调色（数字学习业务的识别色，克制使用） ----
     取值 #9C5A0B：白字压在其上为 5.41:1，作为文字色在纸面上亦 ≥4.5:1，
     满足 WCAG 2.2 AA。旧值 #C77D14 仅为 3.3:1，已废弃。 */
  --accent: #9C5A0B;
  --accent-soft: #FDF4E7;
  --accent-ink: #7A4710;

  /* ---- 圆角（4px 系统） ---- */
  --r-xs: 4px;
  --r-sm: 8px;
  --r-md: 14px;
  --r-lg: 20px;
  --r-xl: 28px;
  --r-pill: 999px;

  /* ---- 阴影（中性分层，不发光） ---- */
  --sh-1: 0 1px 2px rgba(10, 18, 36, 0.05);
  --sh-2: 0 2px 4px rgba(10, 18, 36, 0.04), 0 8px 20px rgba(10, 18, 36, 0.06);
  --sh-3: 0 4px 8px rgba(10, 18, 36, 0.05), 0 18px 44px rgba(10, 18, 36, 0.10);
  --sh-4: 0 8px 16px rgba(10, 18, 36, 0.06), 0 32px 72px rgba(10, 18, 36, 0.13);

  /* ---- 尺寸 ---- */
  --maxw: 1200px;
  --maxw-wide: 1320px;
  --maxw-narrow: 760px;
  --gutter: 28px;
  --header-h: 72px;

  /* ---- 字体 ---- */
  --font-sans: "Inter", "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-serif: "Newsreader", "Iowan Old Style", Georgia, "Songti SC", serif;

  /* ---- 动效 ---- */
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --dur: 0.28s;
  --dur-slow: 0.5s;

  /* ---- 兼容旧类名（viz.css 与历史页面仍引用） ---- */
  --ai-500: var(--brand-400);
  --ai-400: var(--brand-300);
  --ai-300: var(--brand-200);
  --ai-glow: rgba(46, 125, 246, 0.28);
  --lr-500: var(--accent);
  --lr-400: #E0A03A;
  --lr-300: #F0C980;
  --lr-50: var(--accent-soft);
  --lr-glow: rgba(199, 125, 20, 0.24);
  --radius-s: var(--r-xs);
  --radius-m: var(--r-md);
  --radius-l: var(--r-lg);
  --shadow-s: var(--sh-1);
  --shadow-m: var(--sh-2);
  --wrap: var(--maxw);
}

/* 深色区块内重定义线条，使其在深底上可见 */
.dark, .hero, .phero, .cta-band, .footer, .stats, .stat,
.header.dark-mode, .card.dark-card, .dark-section, .evidence-band {
  --line: var(--line-dark);
  --line-strong: var(--line-dark-strong);
}

/* ==========================================================================
   2. Reset
   ========================================================================== */
*, *::before, *::after { box-sizing: border-box; }
html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  scroll-padding-top: calc(var(--header-h) + 16px);
}
body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 17px;
  line-height: 1.68;
  color: var(--text-body);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
  font-feature-settings: "cv02", "cv03", "cv04", "cv11";
}
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
button { font: inherit; cursor: pointer; border: 0; background: none; color: inherit; }
ul, ol { margin: 0; padding: 0; list-style: none; }
h1, h2, h3, h4, h5, h6 {
  color: var(--text-hi);
  font-weight: 700;
  line-height: 1.12;
  letter-spacing: -0.028em;
  margin: 0 0 0.5em;
  text-wrap: balance;
}
h1 { font-size: clamp(2.4rem, 5.2vw, 4.15rem); letter-spacing: -0.038em; }
h2 { font-size: clamp(1.9rem, 3.4vw, 2.9rem); letter-spacing: -0.032em; }
h3 { font-size: clamp(1.3rem, 2vw, 1.62rem); letter-spacing: -0.022em; }
h4, .hl-4 { font-size: 1.11rem; font-weight: 700; letter-spacing: -0.014em; }

/* 标题层级降级后的视觉补偿 ---------------------------------------------
   卡片 / 步骤 / 指标条大量使用 h4 作为小标题，而语义父级是 h2，
   会造成标题大纲跳级（H1→H4）。构建时把这些标题降级为 h3 / h2，
   并挂上 .hl-4 / .hl-5 class —— 字号由 class 决定而非标签决定，
   因此降级前后观感完全一致，大纲则变成严格递增。 */
h1.hl-4, h2.hl-4, h3.hl-4, h4.hl-4, h5.hl-4, h6.hl-4 {
  font-size: 1.11rem; font-weight: 700; letter-spacing: -0.014em;
  margin: 0 0 0.5em; line-height: 1.12; color: var(--text-hi);
}
h1.hl-5, h2.hl-5, h3.hl-5, h4.hl-5, h5.hl-5, h6.hl-5 {
  font-size: 0.95rem; font-weight: 700; letter-spacing: -0.006em;
  margin: 0 0 0.5em; line-height: 1.12; color: var(--text-hi);
}

p { margin: 0 0 1.1em; }
p:last-child { margin-bottom: 0; }

/* 正文最大阅读宽度 —— 长行难读，是廉价模板的典型特征 */
.hero p, .phero p, .section p, .article-body p, .sec-head p { max-width: 68ch; }

/* 焦点可见 —— WCAG 2.2 AA */
:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 3px;
  border-radius: 2px;
}
.dark :focus-visible, .hero :focus-visible, .phero :focus-visible,
.cta-band :focus-visible, .footer :focus-visible {
  outline-color: var(--brand-200);
}

::selection { background: var(--brand-100); color: var(--brand-900); }

/* 跳过导航链接：仅键盘聚焦时可见（WCAG 2.4.1 Bypass Blocks） */
.skip-link {
  position: absolute; left: 12px; top: -60px; z-index: 200;
  padding: 12px 20px; border-radius: 4px;
  background: var(--brand-900); color: #fff;
  font-size: .95rem; font-weight: 600; text-decoration: none;
  transition: top .16s ease;
}
.skip-link:focus { top: 12px; outline: solid 2px var(--brand-400); outline-offset: 2px; }

/* ==========================================================================
   3. 布局
   ========================================================================== */
.wrap { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 var(--gutter); }
.wrap-narrow { max-width: var(--maxw-narrow); }
.section { padding: 112px 0; }
.section-sm { padding: 68px 0; }
.section-lg { padding: 152px 0; }
.dark { background: var(--brand-900); color: var(--text-on-dark-2); }
.dark h1, .dark h2, .dark h3, .dark h4, .dark h5, .dark .hl-4, .dark .hl-5 { color: var(--text-on-dark); }
.dark strong { color: #fff; }
.paper-2 { background: var(--paper-2); }
.paper-3 { background: var(--paper-3); }
.hr { height: 1px; background: var(--line); border: 0; margin: 0; }

/* ==========================================================================
   4. 排版元件
   ========================================================================== */
.eyebrow {
  display: inline-flex; align-items: center; gap: 9px;
  font-size: 0.7rem; font-weight: 700; letter-spacing: 0.15em;
  text-transform: uppercase; color: var(--brand-500); margin-bottom: 20px;
}
.eyebrow::before {
  content: ""; width: 20px; height: 2px; background: var(--brand-400); border-radius: 2px;
}
.dark .eyebrow, .hero .eyebrow, .phero .eyebrow { color: var(--text-on-dark-3); }
.eyebrow.ai::before { background: var(--brand-400); }
.eyebrow.lr::before { background: var(--accent); }
.eyebrow.accent::before { background: var(--accent); }
.eyebrow.no-line::before { display: none; }

.lead { font-size: 1.16rem; line-height: 1.68; color: var(--text-body); }
.dark .lead, .hero .lead { color: var(--text-on-dark-2); }
.lead-lg { font-size: 1.28rem; line-height: 1.6; }

.sec-head { max-width: 72ch; margin-bottom: 52px; }
.sec-head.center { margin-left: auto; margin-right: auto; text-align: center; }
.sec-head h2 { margin: 0 0 16px; }
.sec-head .lead { max-width: 62ch; }
.sec-head.center .lead { margin-left: auto; margin-right: auto; }
.sec-head-row {
  display: flex; align-items: flex-end; justify-content: space-between;
  gap: 40px; margin-bottom: 52px; flex-wrap: wrap;
}
.sec-head-row .sec-head { margin-bottom: 0; }

.divider-label {
  display: flex; align-items: center; gap: 20px;
  font-size: 0.72rem; font-weight: 700; letter-spacing: 0.16em;
  text-transform: uppercase; color: var(--text-faint); margin-bottom: 34px;
}
.divider-label::after { content: ""; flex: 1; height: 1px; background: var(--line); }

.tag {
  display: inline-block; padding: 5px 11px; border-radius: var(--r-xs);
  font-size: 0.72rem; font-weight: 600; letter-spacing: 0.02em;
  background: var(--paper-3); color: var(--text-body);
}
.tag.brand { background: var(--brand-50); color: var(--brand-600); }
.tag.accent { background: var(--accent-soft); color: var(--accent-ink); }
.tag.success { background: var(--success-bg); color: var(--success); }
.tag.warning { background: var(--warning-bg); color: var(--warning); }

/* ==========================================================================
   5. 按钮（企业级：方角为主，克制的阴影，明确的 hover 位移）
   ========================================================================== */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 10px;
  padding: 14px 26px; border-radius: var(--r-sm);
  font-size: 0.94rem; font-weight: 600; letter-spacing: -0.005em;
  line-height: 1.25;
  transition: transform var(--dur) var(--ease), box-shadow var(--dur) var(--ease),
              background var(--dur) var(--ease), color var(--dur) var(--ease),
              border-color var(--dur) var(--ease);
  white-space: nowrap;
  border: 1px solid transparent;
}
.btn:hover { transform: translateY(-1px); }
.btn:active { transform: translateY(0); }
.btn-primary {
  background: var(--brand-400); color: #fff;
  box-shadow: 0 1px 2px rgba(10,18,36,0.10), 0 8px 20px rgba(46,125,246,0.22);
}
.btn-primary:hover { background: var(--brand-500); box-shadow: 0 2px 4px rgba(10,18,36,0.12), 0 14px 32px rgba(46,125,246,0.28); }
.btn-gold { background: var(--accent); color: #fff; box-shadow: 0 1px 2px rgba(10,18,36,0.10), 0 8px 20px rgba(199,125,20,0.22); }
.btn-gold:hover { background: #B06E10; }
.btn-ghost { border-color: var(--line-strong); color: var(--text-hi); background: var(--paper); }
.btn-ghost:hover { border-color: var(--brand-400); color: var(--brand-600); background: var(--brand-50); }
.btn-dark { background: var(--brand-900); color: #fff; }
.btn-dark:hover { background: var(--brand-800); }
.btn-sm { padding: 10px 18px; font-size: 0.86rem; }
.btn-lg { padding: 17px 32px; font-size: 1rem; }
.btn-block { width: 100%; }
.btn[disabled], .btn[aria-disabled="true"] { opacity: 0.5; pointer-events: none; }

.dark .btn-ghost, .hero .btn-ghost, .phero .btn-ghost, .cta-band .btn-ghost,
.footer .btn-ghost, .header.dark-mode .btn-ghost {
  color: #fff; border-color: var(--line-dark-strong); background: transparent;
}
.dark .btn-ghost:hover, .hero .btn-ghost:hover, .phero .btn-ghost:hover,
.cta-band .btn-ghost:hover, .footer .btn-ghost:hover, .header.dark-mode .btn-ghost:hover {
  border-color: #fff; background: rgba(255,255,255,0.10); color: #fff;
}
.btn .arr { transition: transform var(--dur) var(--ease); }
.btn:hover .arr { transform: translateX(3px); }
.btn-row { display: flex; flex-wrap: wrap; gap: 14px; margin-top: 36px; }

/* ==========================================================================
   6. 卡片与网格
   ========================================================================== */
.card {
  background: var(--paper); border: 1px solid var(--line);
  border-radius: var(--r-md); padding: 32px;
  transition: transform var(--dur) var(--ease), box-shadow var(--dur) var(--ease),
              border-color var(--dur) var(--ease);
  position: relative; overflow: hidden;
}
.card-pad-lg { padding: 40px; }
.card-hover:hover { transform: translateY(-3px); box-shadow: var(--sh-3); border-color: var(--brand-200); }
.card-link { display: block; height: 100%; }
.card-link:hover h3:not(.hl-4):not(.hl-5) { color: var(--brand-600); }
.card h3:not(.hl-4):not(.hl-5) { margin-bottom: 12px; transition: color var(--dur) var(--ease); }
.card-num {
  display: inline-block; font-size: 0.76rem; font-weight: 700; letter-spacing: 0.1em;
  color: var(--brand-400); margin-bottom: 16px;
}
.card-more {
  display: inline-flex; align-items: center; gap: 7px; margin-top: 18px;
  font-size: 0.9rem; font-weight: 600; color: var(--brand-500);
}
.card-more .arr { transition: transform var(--dur) var(--ease); }
.card-more:hover .arr { transform: translateX(3px); }

.grid { display: grid; gap: 26px; }
.g2 { grid-template-columns: repeat(2, 1fr); }
.g3 { grid-template-columns: repeat(3, 1fr); }
.g4 { grid-template-columns: repeat(4, 1fr); }
.g5 { grid-template-columns: repeat(5, 1fr); }
.center { text-align: center; }
.c-l { text-align: left; }
.c-r { text-align: right; }

/* 分栏（内容 + 侧栏） */
.split { display: grid; grid-template-columns: 1fr 1fr; gap: 68px; align-items: start; }
.split-60 { display: grid; grid-template-columns: 1.35fr 1fr; gap: 68px; align-items: start; }
.split-40 { display: grid; grid-template-columns: 1fr 1.35fr; gap: 68px; align-items: start; }
.sticky-side { position: sticky; top: calc(var(--header-h) + 28px); }

/* 特性列表 */
.flist { display: grid; gap: 16px; }
.flist-item { display: flex; gap: 14px; align-items: flex-start; }
.flist-item .ico {
  flex: 0 0 22px; width: 22px; height: 22px; margin-top: 3px;
  color: var(--brand-400);
}
.flist-item :is(h4, .hl-4) { margin: 0 0 5px; }
.flist-item p { margin: 0; font-size: 0.95rem; color: var(--text-mute); }

/* 步骤条（企业版） */
.steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 0; }
.step { position: relative; padding: 0 26px 0 0; }
.step::before {
  content: ""; position: absolute; top: 17px; left: 0; right: 0; height: 2px;
  background: var(--line);
}
.step::after {
  content: ""; position: absolute; top: 12px; left: 0;
  width: 12px; height: 12px; border-radius: 50%;
  background: var(--paper); border: 2px solid var(--brand-400);
}
.step :is(h4, .hl-4) { margin: 26px 0 8px; }
.step p { font-size: 0.93rem; color: var(--text-mute); margin: 0; }

/* Bento 网格 */
.bento { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.bento > *:first-child { grid-column: span 2; grid-row: span 2; }

/* 指标卡 */
.stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 0; }
.stat { padding: 0 28px; border-right: 1px solid var(--line); }
.stat:last-child { border-right: 0; }
.stat .k {
  display: block; font-size: clamp(2rem, 3.4vw, 2.9rem); font-weight: 700;
  line-height: 1.06; letter-spacing: -0.035em; color: var(--text-hi); margin-bottom: 8px;
}
.stat .v { display: block; font-size: 0.9rem; color: var(--text-mute); line-height: 1.5; }
.dark .stat .k { color: #fff; }
.dark .stat .v { color: var(--text-on-dark-3); }

/* 引用 */
.quote {
  font-family: var(--font-serif); font-size: clamp(1.25rem, 2.1vw, 1.65rem);
  line-height: 1.5; color: var(--text-hi); letter-spacing: -0.012em;
}
.quote-attr { margin-top: 20px; font-family: var(--font-sans); font-size: 0.88rem; color: var(--text-mute); }

/* 徽标墙 */
.logos {
  display: grid; grid-template-columns: repeat(6, 1fr);
  gap: 1px; background: var(--line); border: 1px solid var(--line);
  border-radius: var(--r-md); overflow: hidden;
}
.logo-item {
  background: var(--paper); padding: 26px 18px; text-align: center;
  font-size: 0.88rem; font-weight: 600; color: var(--text-mute);
  display: flex; align-items: center; justify-content: center; min-height: 92px;
}

/* 徽章行 */
.pill-row { display: flex; flex-wrap: wrap; gap: 10px; }
.pill {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 9px 16px; border: 1px solid var(--line); border-radius: var(--r-pill);
  font-size: 0.88rem; font-weight: 500; color: var(--text-body);
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease),
              background var(--dur) var(--ease);
}
.pill:hover { border-color: var(--brand-400); color: var(--brand-600); background: var(--brand-50); }
.chips { display: flex; flex-wrap: wrap; gap: 9px; }
.chip {
  display: inline-block; padding: 7px 13px; border-radius: var(--r-xs);
  background: var(--paper-2); border: 1px solid var(--line);
  font-size: 0.85rem; color: var(--text-body);
  transition: background var(--dur) var(--ease), border-color var(--dur) var(--ease);
}
.chip:hover { background: var(--brand-50); border-color: var(--brand-200); color: var(--brand-600); }

/* ==========================================================================
   7. 表格
   ========================================================================== */
.tbl-wrap { overflow-x: auto; -webkit-overflow-scrolling: touch; border: 1px solid var(--line); border-radius: var(--r-md); }
.tbl { width: 100%; border-collapse: collapse; font-size: 0.93rem; min-width: 560px; }
.tbl th, .tbl td { padding: 15px 18px; text-align: left; border-bottom: 1px solid var(--line); vertical-align: top; }
.tbl thead th {
  background: var(--paper-2); font-weight: 700; font-size: 0.78rem;
  letter-spacing: 0.07em; text-transform: uppercase; color: var(--text-mute);
}
.tbl tbody tr:last-child td { border-bottom: 0; }
.tbl tbody tr:hover { background: var(--brand-50); }

/* ==========================================================================
   8. 页头与导航
   ========================================================================== */
.header {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: rgba(255, 255, 255, 0.88);
  backdrop-filter: saturate(180%) blur(16px);
  -webkit-backdrop-filter: saturate(180%) blur(16px);
  border-bottom: 1px solid var(--line);
  transition: background var(--dur) var(--ease), border-color var(--dur) var(--ease),
              box-shadow var(--dur) var(--ease);
}
.header.scrolled { box-shadow: var(--sh-2); border-bottom-color: transparent; }
.header-inner {
  display: flex; align-items: center; justify-content: space-between;
  gap: 24px; height: var(--header-h);
}
.logo { display: inline-flex; align-items: center; gap: 11px; flex: 0 0 auto; }
.logo-mark { width: 30px; height: 30px; color: var(--brand-400); }
.logo-mark svg { width: 100%; height: 100%; fill: currentColor; }
.logo-text { display: flex; flex-direction: column; line-height: 1.08; }
.logo-text b { font-size: 1.06rem; font-weight: 700; color: var(--text-hi); letter-spacing: -0.028em; }
.logo-text span { font-size: 0.66rem; font-weight: 600; letter-spacing: 0.17em; text-transform: uppercase; color: var(--text-faint); }
.header.dark-mode { background: transparent; border-bottom-color: transparent; backdrop-filter: none; -webkit-backdrop-filter: none; }
.header.dark-mode .logo-text b { color: #fff; }
.header.dark-mode .logo-text span { color: var(--text-on-dark-3); }
.header.dark-mode .logo-mark { color: var(--brand-300); }

.nav { display: flex; align-items: center; gap: 4px; }
.nav > a, .nav .has-drop > a {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 9px 13px; border-radius: var(--r-xs);
  font-size: 0.9rem; font-weight: 500; color: var(--text-body);
  transition: color var(--dur) var(--ease), background var(--dur) var(--ease);
}
.nav > a:hover, .nav .has-drop > a:hover,
.nav > a.active, .nav .has-drop > a.active { color: var(--brand-600); background: var(--brand-50); }
.header.dark-mode .nav > a, .header.dark-mode .nav .has-drop > a { color: rgba(255,255,255,0.82); }
.header.dark-mode .nav > a:hover, .header.dark-mode .nav .has-drop > a:hover { color: #fff; background: rgba(255,255,255,0.10); }
/* 深色页头下，active 态也要用半透明白而不是浅蓝底（浅蓝在深底上偏灰且对比不足） */
.header.dark-mode .nav > a.active, .header.dark-mode .nav .has-drop > a.active,
.header.dark-mode .nav > a:focus-visible, .header.dark-mode .nav .has-drop > a:focus-visible {
  color: #fff; background: rgba(255,255,255,0.14);
}

/* 下拉 / Mega menu */
.has-drop { position: relative; }
.has-drop > a::after {
  content: ""; width: 7px; height: 7px; margin-left: 2px;
  border-right: 1.6px solid currentColor; border-bottom: 1.6px solid currentColor;
  transform: rotate(45deg) translateY(-2px); opacity: 0.55;
}
.drop {
  position: absolute; top: calc(100% + 12px); left: 50%; transform: translateX(-50%) translateY(-6px);
  min-width: 320px; padding: 12px;
  background: var(--paper); border: 1px solid var(--line);
  border-radius: var(--r-md); box-shadow: var(--sh-4);
  opacity: 0; visibility: hidden; pointer-events: none;
  transition: opacity var(--dur) var(--ease), transform var(--dur) var(--ease), visibility var(--dur);
  z-index: 20;
}
.has-drop:hover .drop, .has-drop:focus-within .drop {
  opacity: 1; visibility: visible; pointer-events: auto;
  transform: translateX(-50%) translateY(0);
}
.drop a {
  display: block; padding: 11px 14px; border-radius: var(--r-xs);
  transition: background var(--dur) var(--ease);
}
.drop a:hover { background: var(--brand-50); }
.drop .d-t { display: block; font-size: 0.92rem; font-weight: 600; color: var(--text-hi); }
.drop .d-s { display: block; font-size: 0.82rem; color: var(--text-mute); margin-top: 2px; line-height: 1.45; }

/* 宽版 mega menu —— 二级项多时用两列 */
.drop.mega { min-width: 560px; display: grid; grid-template-columns: 1fr 1fr; gap: 4px; }

.header-cta { display: flex; align-items: center; gap: 10px; flex: 0 0 auto; }
.nav-cta { display: none; }
.nav-toggle {
  display: none; width: 42px; height: 42px; border-radius: var(--r-xs);
  align-items: center; justify-content: center;
}
.nav-toggle span, .nav-toggle span::before, .nav-toggle span::after {
  display: block; width: 20px; height: 2px; background: var(--text-hi);
  transition: transform var(--dur) var(--ease), opacity var(--dur) var(--ease);
}
.nav-toggle span { position: relative; }
.nav-toggle span::before, .nav-toggle span::after { content: ""; position: absolute; left: 0; }
.nav-toggle span::before { top: -6px; }
.nav-toggle span::after { top: 6px; }
.nav-toggle[aria-expanded="true"] span { background: transparent; }
.nav-toggle[aria-expanded="true"] span::before { transform: translateY(6px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span::after { transform: translateY(-6px) rotate(-45deg); }
.header.dark-mode .nav-toggle span,
.header.dark-mode .nav-toggle span::before,
.header.dark-mode .nav-toggle span::after { background: #fff; }

/* ==========================================================================
   9. Hero
   ========================================================================== */
.hero {
  position: relative; overflow: hidden;
  background: var(--brand-900); color: var(--text-on-dark-2);
  padding: calc(var(--header-h) + 96px) 0 104px;
}
.hero::before {
  content: ""; position: absolute; inset: 0;
  background:
    radial-gradient(900px 460px at 78% 8%, rgba(46,125,246,0.24), transparent 68%),
    radial-gradient(680px 380px at 8% 92%, rgba(28,64,131,0.5), transparent 70%);
  pointer-events: none;
}
.hero::after {
  content: ""; position: absolute; inset: 0; opacity: 0.4; pointer-events: none;
  background-image:
    linear-gradient(rgba(255,255,255,0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.035) 1px, transparent 1px);
  background-size: 64px 64px;
  mask-image: radial-gradient(circle at 50% 30%, #000 20%, transparent 78%);
  -webkit-mask-image: radial-gradient(circle at 50% 30%, #000 20%, transparent 78%);
}
.hero > .wrap { position: relative; z-index: 2; }
.hero h1 { color: #fff; max-width: 17ch; }
.hero h1 .grad {
  background: linear-gradient(96deg, var(--brand-300) 0%, var(--brand-200) 55%, #fff 100%);
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent; color: transparent;
}
.hero-badge {
  display: inline-flex; align-items: center; gap: 10px; flex-wrap: wrap;
  padding: 8px 16px; margin-bottom: 30px;
  border: 1px solid var(--line-dark-strong); border-radius: var(--r-pill);
  font-size: 0.8rem; color: var(--text-on-dark-2);
  background: rgba(255,255,255,0.05);
}
.hero-badge b { color: #fff; font-weight: 600; }
.hero-meta {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 26px;
  margin-top: 68px; padding-top: 34px; border-top: 1px solid var(--line-dark);
}
.hero-meta .k {
  display: block; font-size: clamp(1.6rem, 2.4vw, 2.05rem); font-weight: 700;
  color: #fff; letter-spacing: -0.03em; line-height: 1.1; margin-bottom: 6px;
}
.hero-meta .v { display: block; font-size: 0.85rem; color: var(--text-on-dark-3); line-height: 1.45; }

/* 首页 hero：左文案 + 右信息面板（US enterprise 采购负责人阅读路径） */
.hero-inner {
  display: grid; grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  gap: 64px; align-items: start;
}
.hero-copy .eyebrow { display: block; margin-bottom: 18px; }
.hero-copy h1 { max-width: 15ch; font-size: clamp(2.1rem, 4.2vw, 3.3rem); }
.hero-copy .lead { max-width: 58ch; }
.hero-copy .btn-row { margin-top: 32px; }
.hero-note {
  margin-top: 26px; padding-top: 20px;
  border-top: 1px solid var(--line-dark);
  font-size: 0.86rem; color: var(--text-on-dark-3); max-width: 52ch; line-height: 1.6;
}
.hero-panel {
  background: rgba(255,255,255,0.045);
  border: 1px solid var(--line-dark-strong);
  border-radius: var(--r-lg);
  padding: 30px 30px 26px;
  backdrop-filter: blur(2px);
}
.hero-panel-head { margin-bottom: 22px; }
.hero-panel-label {
  display: block; font-size: 0.76rem; font-weight: 600;
  letter-spacing: 0.09em; text-transform: uppercase;
  color: var(--brand-300);
}
.hero-qa { list-style: none; margin: 0; padding: 0; }
.hero-qa li {
  display: grid; grid-template-columns: 62px 1fr; gap: 16px;
  padding: 15px 0; border-top: 1px solid var(--line-dark);
  align-items: baseline;
}
.hero-qa li:first-child { border-top: 0; padding-top: 0; }
.hero-q {
  font-size: 0.78rem; font-weight: 700; letter-spacing: 0.05em;
  text-transform: uppercase; color: var(--brand-300);
}
.hero-a { font-size: 0.93rem; color: var(--text-on-dark-2); line-height: 1.55; }
.hero-panel-foot {
  margin-top: 22px; padding-top: 18px; border-top: 1px solid var(--line-dark);
  font-size: 0.88rem; color: #fff; font-weight: 500; line-height: 1.5;
}

/* 页面级 hero（内页） */
.phero {
  position: relative; overflow: hidden;
  background: var(--brand-900); color: var(--text-on-dark-2);
  padding: calc(var(--header-h) + 74px) 0 76px;
}
.phero::before {
  content: ""; position: absolute; inset: 0;
  background: radial-gradient(820px 420px at 82% 0%, rgba(46,125,246,0.20), transparent 70%);
  pointer-events: none;
}
.phero > .wrap { position: relative; z-index: 2; }
.phero h1 { color: #fff; max-width: 19ch; }
.phero .lead { color: var(--text-on-dark-2); max-width: 62ch; }
.phero .btn-row { margin-top: 34px; }

.crumbs {
  display: flex; flex-wrap: wrap; align-items: center; gap: 9px;
  font-size: 0.8rem; color: var(--text-on-dark-3); margin-bottom: 26px;
}
.crumbs a { color: var(--text-on-dark-2); transition: color var(--dur) var(--ease); }
.crumbs a:hover { color: #fff; text-decoration: underline; text-underline-offset: 3px; }
.crumbs span { opacity: 0.55; }

/* ==========================================================================
   10. Use-case tabs（参考站标志性模块：标签切换 + 说明 + 图形）
   ========================================================================== */
.uc-tabs { display: grid; grid-template-columns: 300px 1fr; gap: 48px; align-items: start; }
.uc-list { display: grid; gap: 2px; }
.uc-tab {
  display: block; width: 100%; text-align: left;
  padding: 17px 20px; border-radius: var(--r-sm);
  border: 1px solid transparent; border-left: 3px solid var(--line);
  transition: background var(--dur) var(--ease), border-color var(--dur) var(--ease);
}
.uc-tab:hover { background: var(--paper-2); }
.uc-tab[aria-selected="true"] { background: var(--brand-50); border-left-color: var(--brand-400); }
.uc-tab .uc-t { display: block; font-size: 0.98rem; font-weight: 600; color: var(--text-hi); }
.uc-tab .uc-d { display: block; font-size: 0.85rem; color: var(--text-mute); margin-top: 3px; line-height: 1.5; }
.uc-panel { display: none; }
.uc-panel.active { display: block; animation: ucIn 0.4s var(--ease-out); }
@keyframes ucIn { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }

/* 旧 .tabs/.tab 组件（内容页仍用） */
.tabs { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 28px; border-bottom: 1px solid var(--line); padding-bottom: 14px; }
.tab {
  padding: 9px 16px; border-radius: var(--r-xs); font-size: 0.9rem; font-weight: 500;
  color: var(--text-mute); transition: background var(--dur) var(--ease), color var(--dur) var(--ease);
}
.tab:hover { background: var(--paper-2); color: var(--text-hi); }
.tab.active { background: var(--brand-900); color: #fff; }
.tab-panel { display: none; }
.tab-panel.active { display: block; }

/* ==========================================================================
   11. 手风琴（FAQ）
   ========================================================================== */
.acc { border-top: 1px solid var(--line); }
.acc-item { border-bottom: 1px solid var(--line); }
.acc-head {
  display: flex; align-items: flex-start; justify-content: space-between; gap: 24px;
  width: 100%; text-align: left; padding: 24px 0;
  font-size: 1.05rem; font-weight: 600; color: var(--text-hi); line-height: 1.45;
  transition: color var(--dur) var(--ease);
}
.acc-head:hover { color: var(--brand-600); }
.acc-head::after {
  content: "+"; flex: 0 0 auto; font-size: 1.5rem; font-weight: 400;
  color: var(--brand-400); line-height: 1; transition: transform var(--dur) var(--ease);
}
.acc-item.open .acc-head::after { transform: rotate(45deg); }
.acc-body { max-height: 0; overflow: hidden; transition: max-height 0.4s var(--ease); }
.acc-body-inner { padding: 0 0 26px; color: var(--text-body); max-width: 74ch; }
.faq-item { border-bottom: 1px solid var(--line); }

/* ==========================================================================
   12. CTA 带（终局 CTA —— 参考站最有商业说服力的模块）
   ========================================================================== */
.cta-band {
  background: var(--brand-900); color: var(--text-on-dark-2);
  padding: 96px 0; position: relative; overflow: hidden;
}
.cta-band::before {
  content: ""; position: absolute; inset: 0;
  background: radial-gradient(700px 340px at 88% 20%, rgba(46,125,246,0.20), transparent 68%);
  pointer-events: none;
}
.cta-inner { position: relative; z-index: 2; }
.cta-band h2 { color: #fff; max-width: 20ch; }
.cta-band .lead { color: var(--text-on-dark-2); max-width: 58ch; }
.cta-points { display: grid; gap: 12px; margin: 30px 0 0; }
.cta-points li {
  display: flex; gap: 12px; align-items: flex-start;
  font-size: 0.96rem; color: var(--text-on-dark-2);
}
.cta-points li::before {
  content: ""; flex: 0 0 18px; width: 18px; height: 18px; margin-top: 4px;
  border-radius: 50%; background: rgba(46,125,246,0.22);
  border: 1px solid rgba(107,163,255,0.5);
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%236BA3FF' stroke-width='3.4' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M20 6 9 17l-5-5'/%3E%3C/svg%3E");
  background-size: 11px; background-repeat: no-repeat; background-position: center;
}

/* 证据带 */
.evidence-band {
  background: var(--brand-800); color: var(--text-on-dark-2);
  padding: 60px 0; border-top: 1px solid var(--line-dark);
}
.evidence-band .k {
  display: block; font-size: clamp(1.9rem, 3vw, 2.6rem); font-weight: 700;
  color: #fff; letter-spacing: -0.03em; line-height: 1.08; margin-bottom: 6px;
}
.evidence-band .v { display: block; font-size: 0.87rem; color: var(--text-on-dark-3); }

/* ==========================================================================
   13. 表单
   ========================================================================== */
.field { margin-bottom: 20px; }
.field label { display: block; font-size: 0.88rem; font-weight: 600; color: var(--text-hi); margin-bottom: 8px; }
.field input, .field textarea, .field select {
  width: 100%; padding: 13px 15px;
  border: 1px solid var(--line-strong); border-radius: var(--r-sm);
  font: inherit; font-size: 0.96rem; color: var(--text-hi); background: var(--paper);
  transition: border-color var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}
.field input:focus, .field textarea:focus, .field select:focus {
  outline: none; border-color: var(--brand-400);
  box-shadow: 0 0 0 3px rgba(46,125,246,0.16);
}
.field textarea { min-height: 130px; resize: vertical; }
.field .hint { font-size: 0.8rem; color: var(--text-mute); margin-top: 6px; }
.form-note { font-size: 0.84rem; color: var(--text-mute); margin-top: 16px; }
.form-success {
  display: none; padding: 18px 20px; margin-bottom: 22px;
  background: var(--success-bg); border: 1px solid rgba(14,138,95,0.28);
  border-radius: var(--r-sm); color: var(--success); font-size: 0.93rem;
}

/* ==========================================================================
   14. 面包屑（内页浅色版本）
   ========================================================================== */
.crumbs-light { color: var(--text-mute); }
.crumbs-light a { color: var(--text-body); }
.crumbs-light a:hover { color: var(--brand-600); }

/* ==========================================================================
   15. 文章卡与文章正文
   ========================================================================== */
.post-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 26px; }
.post {
  display: flex; flex-direction: column; height: 100%;
  background: var(--paper); border: 1px solid var(--line);
  border-radius: var(--r-md); overflow: hidden;
  transition: transform var(--dur) var(--ease), box-shadow var(--dur) var(--ease), border-color var(--dur) var(--ease);
}
.post:hover { transform: translateY(-3px); box-shadow: var(--sh-3); border-color: var(--brand-200); }
.post .thumb {
  aspect-ratio: 16 / 9; background: linear-gradient(135deg, var(--brand-800), var(--brand-600));
  display: flex; align-items: center; justify-content: center; padding: 24px;
}
.post .thumb .tt { color: #fff; font-size: 1.1rem; font-weight: 700; letter-spacing: -0.02em; text-align: center; }
.post-body { padding: 24px; display: flex; flex-direction: column; flex: 1; }
.post-meta { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; font-size: 0.8rem; color: var(--text-faint); margin-bottom: 12px; }
.post-meta .tag { font-size: 0.7rem; }
.post h3:not(.hl-4):not(.hl-5) { font-size: 1.13rem; line-height: 1.34; margin-bottom: 10px; }
.post h3:not(.hl-4):not(.hl-5) a { transition: color var(--dur) var(--ease); }
.post h3:not(.hl-4):not(.hl-5) a:hover { color: var(--brand-600); }
.post p { font-size: 0.92rem; color: var(--text-mute); margin-bottom: 18px; }
.post .card-more { margin-top: auto; }
/* 索引页文章卡片（blog.html / insights.html 使用的 .body / .meta 结构） */
.post .body { padding: 24px; display: flex; flex-direction: column; flex: 1; }
.post .meta {
  display: flex; flex-wrap: wrap; align-items: center; gap: 10px;
  font-size: 0.8rem; color: var(--text-faint); margin-top: auto;
}
.post .meta .cat { font-weight: 600; color: var(--text-mute); }
.post .thumb.ink { background: linear-gradient(135deg, var(--brand-900), var(--brand-700)); }
.post .thumb .tag { background: rgba(255,255,255,.16); color: #fff; }
.post .thumb .tag.ink { background: rgba(255,255,255,.16); color: #fff; }

.article-head { padding: calc(var(--header-h) + 64px) 0 48px; background: var(--paper-2); }
.article-head h1 { max-width: 21ch; }
.article-meta { display: flex; flex-wrap: wrap; align-items: center; gap: 16px; font-size: 0.85rem; color: var(--text-mute); margin-top: 22px; }
.article-body { max-width: 72ch; padding: 64px 0; }
.article-body h2 { margin-top: 1.9em; margin-bottom: 0.6em; }
.article-body h3:not(.hl-4):not(.hl-5) { margin-top: 1.5em; margin-bottom: 0.5em; }
.article-body ul, .article-body ol { margin: 0 0 1.2em; padding-left: 1.3em; }
.article-body ul li { list-style: disc; margin-bottom: 0.5em; }
.article-body ol li { list-style: decimal; margin-bottom: 0.5em; }
.article-body blockquote {
  margin: 1.6em 0; padding: 4px 0 4px 24px;
  border-left: 3px solid var(--brand-400);
  font-family: var(--font-serif); font-size: 1.16rem; line-height: 1.6; color: var(--text-hi);
}
.article-toc {
  background: var(--paper-2); border: 1px solid var(--line);
  border-radius: var(--r-md); padding: 22px 24px; margin-bottom: 34px;
}
.article-toc :is(h4, .hl-4) { font-size: 0.76rem; letter-spacing: 0.12em; text-transform: uppercase; color: var(--text-mute); margin-bottom: 12px; }
.article-toc a { display: block; font-size: 0.9rem; padding: 5px 0; color: var(--text-body); }
.article-toc a:hover { color: var(--brand-600); }
.article-contact {
  margin-top: 54px; padding: 34px; border-radius: var(--r-md);
  background: var(--paper-2); border: 1px solid var(--line);
}
.article-contact h3:not(.hl-4):not(.hl-5) { margin-bottom: 10px; }
.article-contact .btn-row { margin-top: 22px; }

/* ==========================================================================
   16. 页脚
   ========================================================================== */
.footer {
  background: var(--ink-950); color: var(--text-on-dark-3);
  padding: 88px 0 32px; font-size: 0.92rem;
}
.footer a { color: var(--text-on-dark-2); transition: color var(--dur) var(--ease); }
.footer a:hover { color: #fff; }
.footer-grid { display: grid; grid-template-columns: 1.6fr repeat(4, 1fr); gap: 44px; }
.footer-col h4, .footer-col .hl-5 {
  font-size: 0.73rem; font-weight: 700; letter-spacing: 0.14em; text-transform: uppercase;
  color: #fff; margin-bottom: 18px;
}
.footer-col li { margin-bottom: 11px; }
.footer-blurb { margin: 20px 0; color: var(--text-on-dark-3); max-width: 40ch; line-height: 1.65; }
.footer-offices p { margin-bottom: 10px; font-size: 0.86rem; line-height: 1.55; }
.footer-offices b { color: var(--text-on-dark-2); font-weight: 600; }
.footer .logo-text b { color: #fff; }
.footer .logo-text span { color: var(--text-on-dark-3); }
.footer .logo-mark { color: var(--brand-300); }
.footer-bottom {
  display: flex; align-items: center; justify-content: space-between; gap: 24px;
  flex-wrap: wrap; margin-top: 60px; padding-top: 26px;
  border-top: 1px solid var(--line-dark); font-size: 0.84rem;
}
.footer-bottom span { display: flex; gap: 20px; flex-wrap: wrap; }
.socials { display: flex; gap: 12px; }
.socials a {
  width: 36px; height: 36px; border-radius: var(--r-xs);
  border: 1px solid var(--line-dark); display: inline-flex;
  align-items: center; justify-content: center; transition: border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}
.socials a:hover { border-color: var(--brand-300); background: rgba(46,125,246,0.14); }
.socials svg { width: 17px; height: 17px; fill: currentColor; }

/* 页脚联系区 */
.footer-contact {
  display: grid; grid-template-columns: 1fr auto; gap: 48px; align-items: center;
  padding: 40px; margin-bottom: 62px; border-radius: var(--r-lg);
  background: var(--brand-800); border: 1px solid var(--line-dark);
}
.footer-contact h3:not(.hl-4):not(.hl-5) { color: #fff; font-size: 1.5rem; margin-bottom: 10px; }
.footer-contact p { color: var(--text-on-dark-2); max-width: 56ch; margin: 0; }
.footer-contact-actions { display: grid; gap: 12px; }
.wa-btn {
  display: inline-flex; align-items: center; gap: 13px;
  padding: 14px 20px; border-radius: var(--r-sm);
  background: var(--paper); border: 1px solid var(--line);
  transition: border-color var(--dur) var(--ease), transform var(--dur) var(--ease);
}
.wa-btn:hover { border-color: #25D366; transform: translateY(-1px); }
.wa-ico { display: inline-flex; width: 26px; height: 26px; color: #25D366; }
.wa-ico svg { width: 100%; height: 100%; fill: currentColor; }
.wa-ico-mail { color: var(--brand-400); }
.wa-txt { display: flex; flex-direction: column; line-height: 1.28; }
.wa-txt b { font-size: 0.92rem; color: var(--text-hi); }
.wa-txt span { font-size: 0.82rem; color: var(--text-mute); }

/* ==========================================================================
   17. WhatsApp 按钮
   ========================================================================== */
.btn-wa { background: #25D366; color: #04240F; box-shadow: 0 1px 2px rgba(10,18,36,0.1), 0 8px 20px rgba(37,211,102,0.2); }
.btn-wa:hover { background: #1EBE5A; }
/* 深色区块里的 ghost 按钮会变成透明底（见上方 .btn-ghost 分组规则，
   权重更高）。WhatsApp 品牌绿必须保留 —— 它是全站主要联系入口的识别色。 */
.dark .btn-wa, .hero .btn-wa, .phero .btn-wa, .cta-band .btn-wa,
.footer .btn-wa, .header.dark-mode .btn-wa,
.dark .btn.btn-wa, .hero .btn.btn-wa, .phero .btn.btn-wa,
.cta-band .btn.btn-wa, .footer .btn.btn-wa, .header.dark-mode .btn.btn-wa {
  background: #25D366; color: #04240F;
}
.dark .btn-wa:hover, .hero .btn-wa:hover, .phero .btn-wa:hover,
.cta-band .btn-wa:hover, .footer .btn-wa:hover, .header.dark-mode .btn-wa:hover {
  background: #1EBE5A;
}
.btn-wa svg { width: 19px; height: 19px; fill: currentColor; }
.btn-wa-num { font-variant-numeric: tabular-nums; }
.hdr-wa { padding: 11px 16px; }
.nav-mail { font-size: 0.86rem; color: var(--text-mute); }

/* ==========================================================================
   18. 滚动揭示
   ========================================================================== */
.rv { opacity: 0; transform: translateY(16px); transition: opacity 0.65s var(--ease-out), transform 0.65s var(--ease-out); }
.rv.in { opacity: 1; transform: none; }
.rv.d1 { transition-delay: 0.07s; }
.rv.d2 { transition-delay: 0.14s; }
.rv.d3 { transition-delay: 0.21s; }
.rv.d4 { transition-delay: 0.28s; }
.rv.d5 { transition-delay: 0.35s; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .rv { opacity: 1; transform: none; transition: none; }
  .rv.d1, .rv.d2, .rv.d3, .rv.d4, .rv.d5 { transition: none; }
  *, *::before, *::after { animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; }
}

/* ==========================================================================
   19. 杂项
   ========================================================================== */
.checklist { display: grid; gap: 12px; }
.checklist li { display: flex; gap: 13px; align-items: flex-start; font-size: 0.96rem; }
.checklist li::before {
  content: ""; flex: 0 0 19px; width: 19px; height: 19px; margin-top: 3px;
  border-radius: 50%; background: var(--brand-50);
  border: 1px solid var(--brand-200);
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%232E7DF6' stroke-width='3.4' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M20 6 9 17l-5-5'/%3E%3C/svg%3E");
  background-size: 11px; background-repeat: no-repeat; background-position: center;
}
.callout {
  padding: 26px 30px; border-radius: var(--r-md);
  background: var(--brand-50); border: 1px solid var(--brand-100);
  border-left: 3px solid var(--brand-400);
}
.callout :is(h4, .hl-4) { margin-bottom: 8px; }
.callout p:last-child { margin-bottom: 0; }
.avatar {
  width: 46px; height: 46px; border-radius: 50%;
  background: var(--brand-100); color: var(--brand-600);
  display: inline-flex; align-items: center; justify-content: center;
  font-weight: 700; font-size: 1rem;
}
.ico { color: var(--brand-400); }
.ico svg { width: 100%; height: 100%; }

/* ==========================================================================
   20. 响应式
   ========================================================================== */
@media (max-width: 1100px) {
  .footer-grid { grid-template-columns: 1.4fr repeat(2, 1fr); gap: 36px; }
  .g5 { grid-template-columns: repeat(3, 1fr); }
  .logos { grid-template-columns: repeat(4, 1fr); }
}

@media (max-width: 980px) {
  :root { --gutter: 22px; }
  .section { padding: 84px 0; }
  .section-lg { padding: 104px 0; }
  .section-sm { padding: 56px 0; }
  .split, .split-60, .split-40 { grid-template-columns: 1fr; gap: 40px; }
  .sticky-side { position: static; }
  .g4, .g5, .stats, .hero-meta { grid-template-columns: repeat(2, 1fr); gap: 30px 24px; }
  .hero-inner { grid-template-columns: 1fr; gap: 44px; }
  .stat { border-right: 0; padding: 0; }
  .hero-meta { gap: 28px 24px; }
  .bento { grid-template-columns: repeat(2, 1fr); }
  .bento > *:first-child { grid-column: span 2; grid-row: auto; }
  .post-grid { grid-template-columns: repeat(2, 1fr); }
  .uc-tabs { grid-template-columns: 1fr; gap: 28px; }
  .uc-list { grid-template-columns: repeat(2, 1fr); }
  .steps { grid-template-columns: repeat(2, 1fr); gap: 32px 0; }
  .footer-contact { grid-template-columns: 1fr; gap: 30px; padding: 32px; }
  .drop.mega { min-width: 420px; }
}

@media (max-width: 860px) {
  .header-cta .hdr-wa { display: none; }
  .nav {
    position: fixed; inset: var(--header-h) 0 auto 0;
    flex-direction: column; align-items: stretch; gap: 2px;
    max-height: calc(100vh - var(--header-h)); overflow-y: auto;
    padding: 20px var(--gutter) 32px;
    background: var(--paper); border-bottom: 1px solid var(--line);
    box-shadow: var(--sh-3);
    transform: translateX(100%); transition: transform var(--dur-slow) var(--ease);
  }
  .nav.open { transform: translateX(0); }
  .header.dark-mode .nav { background: var(--brand-900); border-bottom-color: var(--line-dark); }
  .nav > a, .nav .has-drop > a { padding: 13px 4px; font-size: 1rem; border-radius: 0; border-bottom: 1px solid var(--line); }
  .header.dark-mode .nav > a, .header.dark-mode .nav .has-drop > a { color: #fff; border-bottom-color: var(--line-dark); }
  /* 移动端：二级菜单占满整行，展开在顶层项之下 */
  .has-drop { display: block; width: 100%; }
  .drop {
    position: static; top: auto; left: auto; right: auto;
    transform: none; opacity: 1; visibility: visible;
    pointer-events: auto; min-width: 0; width: 100%;
    padding: 0 0 12px 14px; margin: 0;
    border: 0; border-left: 2px solid var(--line); border-radius: 0; box-shadow: none;
    display: none; background: transparent;
  }
  .drop.mega { grid-template-columns: 1fr; }
  .has-drop.open .drop { display: block; }
  /* 移动端：hover 规则里的 translateX(-50%) 必须重置，
     否则下拉会向左偏移半个宽度（桌面端的居中定位残留） */
  .has-drop:hover .drop, .has-drop:focus-within .drop {
    transform: none; opacity: 1; visibility: visible; pointer-events: auto;
  }
  .drop a { padding: 10px 8px; }
  /* 移动端隐藏二级副标题：折叠菜单里一行一个链接更易点 */
  .drop .d-s { display: none; }
  .drop .d-t { font-size: 0.95rem; }
  .drop a { color: var(--text-hi); }
  .drop a:hover { background: var(--brand-50); }
  /* 深色页头（首页 hero 为深底，页头同步 dark-mode）：
     下拉文字必须用浅色，否则深色字落在深色底上不可读。 */
  .header.dark-mode .drop .d-t,
  .header.dark-mode .drop a { color: #fff; }
  .header.dark-mode .drop a:hover { background: rgba(255,255,255,0.10); }
  /* 移动端用 +/− 指示展开状态（桌面端为 hover 箭头） */
  .has-drop > a::after {
    content: "+"; display: block; flex: 0 0 auto;
    width: 22px; height: 22px; line-height: 20px; text-align: center;
    border: 1px solid var(--line); border-radius: var(--r-xs);
    font-size: 0.95rem; color: var(--text-mute);
    transform: none; opacity: 1; margin-left: 0;
    border-right: 1px solid var(--line); border-bottom: 1px solid var(--line);
  }
  .has-drop.open > a::after { content: "\2212"; }
  .has-drop > a[aria-expanded="true"] { color: var(--brand-600); }
  .nav-cta { display: grid; gap: 10px; margin-top: 22px; padding-top: 20px; border-top: 1px solid var(--line); }
  .nav-cta .btn-wa { width: 100%; justify-content: center; }
  .nav-cta .btn-wa-num { white-space: nowrap; }
  .has-drop > a { display: flex; align-items: center; justify-content: space-between; gap: 12px; }
  .nav-toggle { display: inline-flex; }
  .footer-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 640px) {
  :root { --gutter: 18px; }
  body { font-size: 16.5px; }
  .section { padding: 68px 0; }
  .section-lg { padding: 84px 0; }
  .section-sm { padding: 48px 0; }
  .hero { padding: calc(var(--header-h) + 46px) 0 62px; }
  .phero { padding: calc(var(--header-h) + 54px) 0 58px; }
  .g2, .g3, .g4, .g5, .post-grid, .stats, .hero-meta, .uc-list { grid-template-columns: 1fr; }
  .bento { grid-template-columns: 1fr; }
  .bento > *:first-child { grid-column: auto; }
  .logos { grid-template-columns: repeat(2, 1fr); }
  .steps { grid-template-columns: 1fr; }
  .card { padding: 24px; }
  .card-pad-lg { padding: 28px; }
  .footer-grid { grid-template-columns: 1fr; gap: 32px; }
  .footer-bottom { flex-direction: column; align-items: flex-start; }
  .btn { width: 100%; }
  .btn-row .btn { width: 100%; }
  .hero-meta { grid-template-columns: repeat(2, 1fr); }
  .cta-band { padding: 68px 0; }
  .article-body { padding: 44px 0; }
  .drop.mega { min-width: 0; }
}

/* 打印 —— 企业文档常见需求（合规培训材料常被打印） */
@media print {
  .header, .footer, .cta-band, .btn, .btn-row, .nav, .article-contact { display: none !important; }
  body { font-size: 11pt; color: #000; }
  .hero, .phero, .article-head { background: none; color: #000; padding: 0 0 18pt; }
  .hero h1, .phero h1, .article-head h1 { color: #000; }
  .hero-inner { grid-template-columns: 1fr; }
  .hero-panel { border: 1px solid #ccc; background: none; }
  a { text-decoration: underline; }
}

/* ---------------------------------------------------------------------------
   表单错误态与状态提示（配合 assets/js/forms.js）
   WCAG 2.2 AA：错误不仅靠颜色标示，同时有 aria-invalid 与文字提示。
   --------------------------------------------------------------------------- */
.field-invalid input,
.field-invalid select,
.field-invalid textarea,
[aria-invalid="true"] {
  border-color: #C6382F !important;
  box-shadow: 0 0 0 3px rgba(198, 56, 47, 0.16);
}
.field-invalid > span,
.field-invalid > label {
  color: #C6382F;
}
.field {
  position: relative;
}
[data-form-status] {
  line-height: 1.7;
}
[data-form-status] a {
  text-decoration: underline;
  color: inherit;
}
[data-form-status][role="alert"] {
  border-color: #C6382F !important;
}