/* ==========================================================================
   豆包官网 · 工业配电箱闸刀开关合闸 · 电气控制风 (Industrial Switchboard / Knife Switch)
   色彩体系：绝缘电木灰 (#2C3036 / #3D434C / #E2E6EC) + 高压警示橙 (#FF5A00 / #FF7A1A) + 首屏浅紫网格光晕
   骨架体系：纵向三段式配电盘骨架，CTA设计为推挽式断路闸刀开关
   ========================================================================== */

:root {
  /* 电气控制风核心色板：绝缘电木灰 + 高压警示橙 */
  --bakelite-bg: #E2E6EC;           /* 工业配电箱外柜冷电木灰底 */
  --bakelite-plate: #D3D9E2;        /* 三段式配电盘母线槽衬底灰 */
  --bakelite-dark: #1F2328;         /* 绝缘电木深黑灰 */
  --bakelite-panel: #2E343D;        /* 配电盘隔离开关底座灰 */
  --bakelite-muted: #525B68;        /* 电气铭牌次级刻度灰 */
  --bakelite-border: #A8B2C0;       /* 导轨绝缘子边线 */

  --voltage-orange: #FF5500;        /* 高压警示橙主色 */
  --voltage-bright: #FF7B1A;        /* 电弧合闸亮橙高光 */
  --voltage-soft: #FFF1E8;          /* 高压警示微暖浅橙底 */
  --copper-bus: #C86D28;            /* 紫铜母线排金属色 */

  /* 首屏浅紫网格加顶部光晕 */
  --violet-grid: rgba(118, 92, 232, 0.095);
  --violet-glow: rgba(142, 108, 252, 0.24);

  --shadow-switchboard: 0 12px 30px rgba(31, 35, 40, 0.12), inset 0 1px 0 rgba(255, 255, 255, 0.8);
  --shadow-engaged: 0 18px 40px rgba(255, 85, 0, 0.26), 0 0 0 2px var(--voltage-orange);

  --max-w: 1200px;
  --font-sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  --font-mono: "JetBrains Mono", Consolas, "Courier New", monospace;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  background-color: var(--bakelite-bg);
  color: var(--bakelite-dark);
}

body {
  font-family: var(--font-sans);
  background-color: var(--bakelite-bg);
  color: var(--bakelite-dark);
  line-height: 1.72;
  overflow-x: hidden;
  position: relative;
  /* 纵向三段式配电盘母线导轨与电气绝缘网格底纹 */
  background-image:
    linear-gradient(90deg,
      rgba(46, 52, 61, 0.07) 0%,
      rgba(46, 52, 61, 0.07) 18px,
      transparent 18px,
      transparent 33.33%,
      rgba(255, 85, 0, 0.045) 33.33%,
      rgba(255, 85, 0, 0.045) calc(33.33% + 2px),
      transparent calc(33.33% + 2px),
      transparent 66.66%,
      rgba(255, 85, 0, 0.045) 66.66%,
      rgba(255, 85, 0, 0.045) calc(66.66% + 2px),
      transparent calc(66.66% + 2px),
      transparent calc(100% - 18px),
      rgba(46, 52, 61, 0.07) calc(100% - 18px),
      rgba(46, 52, 61, 0.07) 100%
    ),
    repeating-linear-gradient(180deg, rgba(46, 52, 61, 0.04) 0px, rgba(46, 52, 61, 0.04) 1px, transparent 1px, transparent 40px);
}

a {
  color: inherit;
  text-decoration: none;
  transition: all 0.26s cubic-bezier(0.22, 1, 0.36, 1);
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

ul, ol {
  list-style: none;
}

.container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 32px;
}

/* ==========================================================================
   纵向三段式配电盘骨架 (Busbar Tier I / II / III) 与合闸指示铭牌
   ========================================================================== */
.ink-bleed-section {
  position: relative;
  padding: 90px 0;
  border-bottom: 4px solid var(--bakelite-panel);
}

/* 章节顶部配电盘母线铜排合闸铭牌 */
.ink-bleed-section::before {
  content: "⚡ BUSBAR TIER [I · II · III] // KNIFE SWITCH ENGAGED · 380V AC ⚡";
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  padding: 3px 20px;
  background: var(--bakelite-dark);
  color: #FFFFFF;
  border: 2px solid var(--voltage-orange);
  border-radius: 4px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 800;
  letter-spacing: 0.08em;
  white-space: nowrap;
  z-index: 3;
}

.scenarios-bg {
  background-color: var(--bakelite-plate);
  background-image:
    repeating-linear-gradient(135deg, rgba(255, 85, 0, 0.04) 0px, rgba(255, 85, 0, 0.04) 10px, transparent 10px, transparent 20px),
    linear-gradient(180deg, rgba(31, 35, 40, 0.04) 0%, transparent 100%);
}

.ink-reveal {
  opacity: 1;
  transform: translateY(0);
  transition: opacity 0.6s ease, transform 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

.js-ready .ink-reveal {
  opacity: 0;
  transform: translateY(20px);
}

.js-ready .ink-reveal.is-inked {
  opacity: 1;
  transform: translateY(0);
}

/* 章节标题区 */
.section-header {
  text-align: center;
  max-width: 760px;
  margin: 0 auto 56px;
  position: relative;
  z-index: 2;
}

.ink-seal-tag {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 6px 18px;
  font-size: 12.5px;
  font-weight: 800;
  letter-spacing: 0.06em;
  color: var(--bakelite-dark);
  background: #FFFFFF;
  border: 2px solid var(--bakelite-panel);
  border-left: 7px solid var(--voltage-orange);
  border-right: 7px solid var(--voltage-orange);
  border-radius: 4px;
  margin-bottom: 16px;
  box-shadow: var(--shadow-switchboard);
}

.ink-seal-stamp {
  display: inline-block;
  padding: 2px 8px;
  font-size: 11px;
  font-weight: 800;
  color: #FFF;
  background: var(--voltage-orange);
  border-radius: 3px;
  font-family: var(--font-mono);
}

.section-title {
  font-size: clamp(26px, 3.6vw, 40px);
  font-weight: 900;
  color: var(--bakelite-dark);
  line-height: 1.25;
  margin-bottom: 14px;
}

.section-desc {
  font-size: 16px;
  color: var(--bakelite-muted);
  font-weight: 500;
  line-height: 1.75;
}

/* ==========================================================================
   推挽式断路闸刀开关 (Push-Pull Knife Switch CTA) 样式体系
   ========================================================================== */
.btn-capsule-start,
.hero-embed-btn,
.btn-primary-gradient,
.btn-secondary-outline,
.platform-btn,
.mobile-btn-chat,
.mobile-btn-dl {
  position: relative;
  transition: transform 0.24s cubic-bezier(0.34, 1.56, 0.64, 1), box-shadow 0.24s ease, background-color 0.24s ease;
}

/* 推挽式闸刀绝缘手柄横杠刻槽 */
.btn-primary-gradient::after,
.btn-capsule-start::after,
.hero-embed-btn::after {
  content: "▐▌ON";
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin-left: 8px;
  padding: 2px 7px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 900;
  line-height: 1.1;
  background: rgba(31, 35, 40, 0.88);
  color: var(--voltage-bright);
  border: 1.5px solid rgba(255, 255, 255, 0.55);
  border-radius: 4px;
  transform: translateY(-2px);
  transition: transform 0.22s cubic-bezier(0.34, 1.56, 0.64, 1), background-color 0.22s ease, color 0.22s ease;
}

.btn-secondary-outline::after {
  content: "▐▌PULL";
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin-left: 8px;
  padding: 2px 7px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 900;
  line-height: 1.1;
  background: var(--bakelite-panel);
  color: #FFFFFF;
  border-radius: 4px;
  transform: translateY(-2px);
  transition: transform 0.22s cubic-bezier(0.34, 1.56, 0.64, 1), background-color 0.22s ease;
}

/* 悬停或推入合闸时：闸刀手柄下压就位，触点亮起高压警示橙 */
.btn-primary-gradient:hover::after,
.btn-capsule-start:hover::after,
.hero-embed-btn:hover::after,
.btn-secondary-outline:hover::after,
.is-knife-engaged::after {
  transform: translateY(2px) scale(1.04);
  background: #FFFFFF;
  color: var(--voltage-orange);
}

/* ==========================================================================
   1. 顶部导航
   左侧是圆形「豆」标和品牌名，右侧是「登录」文字链和胶囊按钮「开始使用」。
   窄屏时中间锚点收起，底部固定「下载 App」和「开始对话」。
   ========================================================================== */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  height: 70px;
  background: rgba(226, 230, 236, 0.94);
  backdrop-filter: saturate(1.8) blur(16px);
  -webkit-backdrop-filter: saturate(1.8) blur(16px);
  border-bottom: 3px solid var(--bakelite-panel);
}

.nav-inner {
  max-width: var(--max-w);
  height: 100%;
  margin: 0 auto;
  padding: 0 32px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.nav-brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
}

.brand-dou-circle {
  position: relative;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--bakelite-dark);
  border: 2.5px solid var(--voltage-orange);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  box-shadow: 0 4px 12px rgba(255, 85, 0, 0.28);
  flex-shrink: 0;
}

.brand-dou-circle img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.brand-dou-badge {
  position: absolute;
  right: -2px;
  bottom: -2px;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--voltage-orange);
  color: #FFF;
  font-size: 11px;
  font-weight: 900;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1.5px solid #FFF;
}

.brand-meta {
  display: flex;
  flex-direction: column;
}

.brand-name {
  font-size: 19px;
  font-weight: 900;
  color: var(--bakelite-dark);
  line-height: 1.2;
  display: flex;
  align-items: center;
  gap: 8px;
}

.brand-sub {
  font-size: 11.5px;
  color: var(--bakelite-muted);
  font-family: var(--font-mono);
}

.nav-anchors {
  display: flex;
  align-items: center;
  gap: 18px;
}

.nav-link {
  font-size: 14px;
  color: var(--bakelite-panel);
  font-weight: 700;
  padding: 6px 12px;
  border-radius: 6px;
}

.nav-link:hover,
.nav-link.active {
  color: #FFF;
  background: var(--voltage-orange);
}

.nav-right {
  display: flex;
  align-items: center;
  gap: 16px;
}

.nav-login-link {
  font-size: 14.5px;
  font-weight: 800;
  color: var(--bakelite-dark);
  padding: 6px 10px;
}

.nav-login-link:hover {
  color: var(--voltage-orange);
}

/* 胶囊按钮「开始使用」（兼具推挽闸刀合闸触点） */
.btn-capsule-start {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 4px;
  padding: 9px 20px;
  border-radius: 999px;
  background: linear-gradient(135deg, var(--bakelite-dark) 0%, var(--voltage-orange) 62%, var(--voltage-bright) 100%);
  color: #FFF;
  font-size: 14px;
  font-weight: 800;
  box-shadow: 0 5px 0 var(--bakelite-dark), 0 8px 18px rgba(255, 85, 0, 0.30);
}

.btn-capsule-start:hover {
  transform: translateY(2px);
  box-shadow: 0 2px 0 var(--bakelite-dark), 0 6px 14px rgba(255, 85, 0, 0.38);
}

/* ==========================================================================
   2. 首屏 (Hero)
   内容居中。最上是呼吸点徽章「AI 智能助手 · 多端同步 · 免费使用」，
   下面是大标题「豆包，你的 AI 助手」和两行副标题。
   再往下是圆角输入框，按钮嵌在框内，文案是「开始对话」。
   主按钮「免费开始使用」是满宽渐变，次按钮「下载 App」是白底线框。
   最底一行写支持网页、iOS、Android、Windows、macOS。
   背景是浅紫网格加顶部光晕 + 纵向三段式配电盘骨架。
   ========================================================================== */
.hero-section {
  position: relative;
  padding: 74px 0 66px;
  overflow: hidden;
  /* 浅紫网格加顶部光晕，融合高压警示橙微光 */
  background-image:
    radial-gradient(ellipse 76% 56% at 50% 0%, var(--violet-glow) 0%, rgba(255, 85, 0, 0.12) 48%, transparent 78%),
    linear-gradient(to right, var(--violet-grid) 1px, transparent 1px),
    linear-gradient(to bottom, var(--violet-grid) 1px, transparent 1px);
  background-size: 100% 100%, 32px 32px, 32px 32px;
  border-bottom: 4px solid var(--bakelite-panel);
}

.hero-center-box {
  max-width: 820px;
  margin: 0 auto;
  text-align: center;
  position: relative;
  z-index: 2;
  padding: 40px 36px 34px;
  background: rgba(255, 255, 255, 0.90);
  border: 3px solid var(--bakelite-panel);
  border-top: 8px solid var(--voltage-orange);
  border-radius: 16px;
  box-shadow: var(--shadow-switchboard);
}

/* 纵向三段式配电盘侧边铜排分割标尺 */
.hero-center-box::before {
  content: "TIER-01 [BUSBAR]  ──  TIER-02 [BREAKER]  ──  TIER-03 [OUTPUT]";
  display: inline-block;
  margin-bottom: 14px;
  padding: 3px 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 800;
  color: var(--voltage-orange);
  background: var(--voltage-soft);
  border: 1px solid var(--voltage-orange);
  border-radius: 4px;
}

.breathing-badge {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 7px 20px;
  border-radius: 999px;
  background: #FFFFFF;
  border: 2px solid var(--bakelite-panel);
  font-size: 13.5px;
  font-weight: 800;
  color: var(--bakelite-dark);
  margin-bottom: 22px;
  box-shadow: var(--shadow-switchboard);
}

.breathing-dot {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--voltage-orange);
  box-shadow: 0 0 0 0 rgba(255, 85, 0, 0.78);
  animation: arcPulse 2s infinite;
}

@keyframes arcPulse {
  0% { box-shadow: 0 0 0 0 rgba(255, 85, 0, 0.78); }
  70% { box-shadow: 0 0 0 9px rgba(255, 85, 0, 0); }
  100% { box-shadow: 0 0 0 0 rgba(255, 85, 0, 0); }
}

.hero-h1 {
  font-size: clamp(36px, 5.2vw, 56px);
  font-weight: 900;
  line-height: 1.18;
  letter-spacing: -0.02em;
  margin-bottom: 12px;
  background: linear-gradient(120deg, var(--bakelite-dark) 0%, var(--bakelite-panel) 45%, var(--voltage-orange) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-h1-sub {
  display: block;
  font-size: clamp(18px, 2.3vw, 24px);
  font-weight: 800;
  color: var(--voltage-orange);
  -webkit-text-fill-color: var(--voltage-orange);
  margin-top: 10px;
}

.hero-subtitle {
  font-size: 17px;
  color: var(--bakelite-muted);
  line-height: 1.8;
  max-width: 700px;
  margin: 18px auto 28px;
}

/* 圆角输入框，按钮嵌在框内，文案是「开始对话」 */
.hero-input-bar {
  display: flex;
  align-items: center;
  max-width: 680px;
  margin: 0 auto 22px;
  padding: 7px 8px 7px 22px;
  background: #FFFFFF;
  border: 2.5px solid var(--bakelite-panel);
  border-radius: 999px;
  box-shadow: var(--shadow-switchboard);
  transition: border-color 0.25s, box-shadow 0.25s;
}

.hero-input-bar:focus-within {
  border-color: var(--voltage-orange);
  box-shadow: var(--shadow-engaged);
}

.hero-input-field {
  flex: 1;
  border: none;
  outline: none;
  background: transparent;
  font-size: 15.5px;
  color: var(--bakelite-dark);
  font-family: inherit;
  min-width: 0;
}

.hero-input-field::placeholder {
  color: #748091;
}

.hero-embed-btn {
  padding: 11px 22px;
  border: none;
  border-radius: 999px;
  background: var(--voltage-orange);
  color: #FFF;
  font-size: 15px;
  font-weight: 800;
  cursor: pointer;
  flex-shrink: 0;
  box-shadow: 0 4px 0 var(--bakelite-dark);
}

.hero-embed-btn:hover {
  background: var(--bakelite-dark);
  transform: translateY(2px);
  box-shadow: 0 2px 0 var(--voltage-orange);
}

/* 主按钮「免费开始使用」是满宽渐变（推挽式合闸闸刀开关），次按钮「下载 App」是白底线框 */
.hero-cta-group {
  max-width: 680px;
  margin: 0 auto 22px;
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 14px;
}

.btn-primary-gradient {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  width: 100%;
  padding: 15px 24px;
  border-radius: 999px;
  background: linear-gradient(135deg, var(--bakelite-dark) 0%, var(--voltage-orange) 54%, var(--voltage-bright) 100%);
  color: #FFF;
  font-size: 16px;
  font-weight: 800;
  border: 2px solid var(--bakelite-dark);
  box-shadow: 0 6px 0 var(--bakelite-dark), 0 12px 26px rgba(255, 85, 0, 0.28);
  cursor: pointer;
}

.btn-primary-gradient:hover {
  transform: translateY(3px);
  box-shadow: 0 3px 0 var(--bakelite-dark), 0 8px 18px rgba(255, 85, 0, 0.38);
}

.btn-secondary-outline {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  width: 100%;
  padding: 15px 24px;
  border-radius: 999px;
  background: #FFFFFF;
  color: var(--bakelite-dark);
  border: 2.5px solid var(--bakelite-panel);
  font-size: 16px;
  font-weight: 800;
  box-shadow: 0 6px 0 var(--bakelite-panel);
  cursor: pointer;
}

.btn-secondary-outline:hover {
  border-color: var(--voltage-orange);
  color: var(--voltage-orange);
  transform: translateY(3px);
  box-shadow: 0 3px 0 var(--voltage-orange);
}

.hero-platforms-note {
  font-size: 13.5px;
  color: var(--bakelite-muted);
  font-weight: 700;
}

/* ==========================================================================
   3. 对话预览 (拟态对话卡 · 配电盘观察窗)
   ========================================================================== */
.dialogue-preview-wrap {
  max-width: 920px;
  margin: 44px auto 0;
  position: relative;
  z-index: 2;
}

.dialogue-mock-card {
  position: relative;
  background: #FFFFFF;
  border: 3px solid var(--bakelite-panel);
  border-radius: 16px;
  box-shadow: var(--shadow-switchboard);
  overflow: hidden;
}

.mock-window-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 22px;
  background: var(--bakelite-dark);
  color: #FFF;
  border-bottom: 3px solid var(--voltage-orange);
}

.window-dots {
  display: flex;
  gap: 8px;
}

.win-dot {
  width: 11px;
  height: 11px;
  border-radius: 50%;
}

.win-dot.red { background: var(--voltage-orange); }
.win-dot.yellow { background: #F5A623; }
.win-dot.green { background: #2ECC71; }

.window-title {
  font-size: 13px;
  color: #E2E6EC;
  font-weight: 700;
  font-family: var(--font-mono);
}

.window-status {
  font-size: 12px;
  color: var(--voltage-bright);
  font-weight: 800;
  font-family: var(--font-mono);
}

.dialogue-stream {
  padding: 28px 28px 24px;
  display: flex;
  flex-direction: column;
  gap: 18px;
  text-align: left;
}

.chat-row {
  display: flex;
  gap: 14px;
  align-items: flex-start;
}

.chat-row.user {
  justify-content: flex-end;
}

.chat-avatar {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  font-weight: 800;
  background: var(--bakelite-dark);
  color: #FFF;
  overflow: hidden;
  border: 2px solid var(--voltage-orange);
}

.chat-avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.chat-bubble {
  max-width: 78%;
  padding: 14px 18px;
  font-size: 14.5px;
  line-height: 1.7;
  border-radius: 10px;
}

.chat-row.user .chat-bubble {
  background: var(--bakelite-dark);
  color: #FFF;
  border-left: 4px solid var(--voltage-orange);
}

.chat-row.ai .chat-bubble {
  background: var(--voltage-soft);
  color: var(--bakelite-dark);
  border: 1.5px solid var(--bakelite-border);
}

.chat-meta-tag {
  display: inline-block;
  font-size: 11.5px;
  color: var(--voltage-orange);
  font-weight: 800;
  font-family: var(--font-mono);
  margin-bottom: 4px;
}

.dialogue-visual-showcase {
  margin-top: 26px;
  padding: 18px;
  background: #FFFFFF;
  border: 2.5px solid var(--bakelite-panel);
  border-radius: 16px;
  box-shadow: var(--shadow-switchboard);
}

.dialogue-visual-showcase img {
  width: 100%;
  border: 1px solid var(--bakelite-border);
  border-radius: 8px;
}

.showcase-caption {
  margin-top: 12px;
  font-size: 13.5px;
  color: var(--bakelite-muted);
  text-align: center;
  font-weight: 700;
}

/* ==========================================================================
   4. 信任条
   四句横排：多端同步、传输加密、中文场景优化、未成年人保护。没有大图标堆砌。
   ========================================================================== */
.trust-strip {
  background: var(--bakelite-dark);
  color: #FFF;
  padding: 22px 0;
  border-bottom: 4px solid var(--voltage-orange);
}

.trust-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  text-align: center;
}

.trust-item {
  font-size: 15px;
  font-weight: 800;
  color: #FFFFFF;
  padding: 6px 12px;
  border-right: 1px solid rgba(255, 255, 255, 0.2);
}

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

.trust-item span {
  display: block;
  font-size: 12.5px;
  color: #C4CEDB;
  font-weight: 400;
  margin-top: 3px;
}

/* ==========================================================================
   5. 能力矩阵 & 纵向三段式配电盘模块卡片系统
   ========================================================================== */
.matrix-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 22px;
  align-items: stretch;
}

.white-ink-card,
.scenario-card,
.qa-card,
.platform-dl-card,
.tech-short-card,
.review-card,
.security-module-card {
  position: relative;
  background-color: #FFFFFF;
  border: 2.5px solid var(--bakelite-panel);
  border-top: 7px solid var(--voltage-orange);
  border-radius: 12px;
  box-shadow: var(--shadow-switchboard);
  transition: transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1), box-shadow 0.28s ease, border-color 0.28s ease;
}

/* 卡片右上角闸刀断路合闸触点状态 */
.white-ink-card::before,
.tech-short-card::before,
.security-module-card::before {
  content: "⚡ CLOSED [ON]";
  position: absolute;
  top: 10px;
  right: 14px;
  font-family: var(--font-mono);
  font-size: 10.5px;
  font-weight: 800;
  color: var(--voltage-orange);
  background: var(--voltage-soft);
  padding: 2px 7px;
  border: 1px solid var(--voltage-orange);
  border-radius: 3px;
}

/* 纵向三段式配电盘底栏铜排刻度 */
.white-ink-card {
  padding: 28px 22px 24px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.white-ink-card:hover,
.scenario-card:hover,
.qa-card:hover,
.platform-dl-card:hover,
.tech-short-card:hover,
.review-card:hover,
.security-module-card:hover {
  transform: translateY(-4px);
  border-color: var(--voltage-orange);
  box-shadow: var(--shadow-engaged);
}

.card-ink-index {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background: var(--bakelite-dark);
  color: var(--voltage-bright);
  border: 2px solid var(--voltage-orange);
  border-radius: 8px;
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 900;
  margin-bottom: 16px;
}

.card-title {
  font-size: 19px;
  font-weight: 900;
  color: var(--bakelite-dark);
  margin-bottom: 10px;
}

.card-two-lines {
  font-size: 14.5px;
  color: var(--bakelite-muted);
  line-height: 1.65;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  margin-bottom: 14px;
  padding-top: 10px;
  border-top: 1.5px dashed var(--bakelite-border);
}

.card-more-link {
  font-size: 13px;
  font-weight: 800;
  color: var(--voltage-orange);
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding-top: 8px;
  border-top: 2px solid var(--bakelite-bg);
}

/* ==========================================================================
   6. 场景
   按身份分块：学习、工作、创作、编程、生活。每块有英文小标，再加可直接照抄的提问。
   ========================================================================== */
.scenarios-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.scenario-card {
  padding: 28px 24px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.scenario-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--bakelite-border);
}

.scenario-cn {
  font-size: 21px;
  font-weight: 900;
  color: var(--bakelite-dark);
}

.scenario-en {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 800;
  color: var(--voltage-orange);
  letter-spacing: 0.06em;
}

.copy-prompt-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.copy-prompt-item {
  padding: 10px 14px;
  background: var(--bakelite-bg);
  border: 1.5px solid var(--bakelite-border);
  border-left: 5px solid var(--voltage-orange);
  border-radius: 6px;
  font-size: 13.5px;
  color: var(--bakelite-dark);
  font-weight: 600;
  line-height: 1.55;
  cursor: pointer;
}

.copy-prompt-item:hover {
  background: var(--voltage-soft);
  border-color: var(--voltage-orange);
}

.scenario-banner-card {
  background: #FFFFFF;
  border: 2.5px solid var(--bakelite-panel);
  border-top: 7px solid var(--voltage-orange);
  border-radius: 12px;
  padding: 20px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  box-shadow: var(--shadow-switchboard);
}

.scenario-banner-card img {
  margin-bottom: 12px;
  border-radius: 8px;
}

/* ==========================================================================
   7. 问答示例 (纵向三段式：上段铭牌 / 中段用户输入 / 下段系统交付)
   三列卡片，覆盖职场写作、编程调试、长文总结。上句是用户输入，下句是系统交付。
   ========================================================================== */
.qa-grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.qa-card {
  padding: 26px 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.qa-card-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--bakelite-border);
}

.qa-tag {
  padding: 4px 12px;
  background: var(--voltage-orange);
  color: #FFF;
  border-radius: 4px;
  font-size: 12px;
  font-weight: 800;
}

.qa-user-box {
  padding: 14px 16px;
  background: var(--voltage-soft);
  border-left: 4px solid var(--voltage-orange);
  border-radius: 6px;
  font-size: 14px;
  color: var(--bakelite-dark);
  font-weight: 700;
}

.qa-ai-box {
  padding: 14px 16px;
  background: var(--bakelite-bg);
  border: 1.5px solid var(--bakelite-border);
  border-radius: 8px;
  font-size: 13.5px;
  color: var(--bakelite-panel);
  line-height: 1.7;
  flex: 1;
}

/* ==========================================================================
   8. 下载
   说明同一账号多端同步，并配扫码去应用商店。和首屏的「下载 App」是同一条路径。
   ========================================================================== */
.download-section {
  background: var(--bakelite-plate);
}

.download-split {
  display: grid;
  grid-template-columns: 330px 1fr;
  gap: 28px;
  align-items: stretch;
}

.qr-panel {
  position: relative;
  background: #FFFFFF;
  border: 2.5px solid var(--bakelite-panel);
  border-top: 7px solid var(--voltage-orange);
  border-radius: 12px;
  padding: 32px 26px;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-switchboard);
}

.qr-code-box {
  width: 156px;
  height: 156px;
  padding: 14px;
  background: #FFF;
  border: 3px solid var(--bakelite-dark);
  border-radius: 10px;
  margin: 16px 0;
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  grid-template-rows: repeat(5, 1fr);
  gap: 5px;
}

.qr-pixel { background: var(--bakelite-dark); }
.qr-pixel.light { background: var(--voltage-orange); }
.qr-pixel.blank { background: transparent; }

.platforms-grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}

.platform-dl-card {
  padding: 22px 20px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.platform-dl-card h3 {
  font-size: 18px;
  font-weight: 900;
  margin-bottom: 6px;
}

.platform-dl-card p {
  font-size: 13.5px;
  color: var(--bakelite-muted);
  margin-bottom: 16px;
}

.platform-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 9px 16px;
  background: var(--voltage-orange);
  color: #FFF;
  border-radius: 6px;
  font-size: 13px;
  font-weight: 800;
  box-shadow: 0 3px 0 var(--bakelite-dark);
}

.platform-btn:hover {
  background: var(--bakelite-dark);
  transform: translateY(2px);
  box-shadow: 0 1px 0 var(--voltage-orange);
}

/* ==========================================================================
   9. 技术底座
   四列，序号 01 到 04：语言理解、语音交互、图像、智能体。比上面的能力卡更短。
   ========================================================================== */
.tech-grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.tech-short-card {
  padding: 22px 20px;
}

.tech-num {
  font-family: var(--font-mono);
  font-size: 28px;
  font-weight: 900;
  color: var(--voltage-orange);
  line-height: 1.1;
  margin-bottom: 8px;
}

.tech-short-card h3 {
  font-size: 17px;
  font-weight: 900;
  margin-bottom: 6px;
}

.tech-short-card p {
  font-size: 13.5px;
  color: var(--bakelite-muted);
  line-height: 1.55;
}

/* ==========================================================================
   10. 评价
   三列引用：在校研究生、互联网运营、后端工程师。页内写明这些是示例，上线前要换成授权评价。
   ========================================================================== */
.review-disclaimer {
  text-align: center;
  font-size: 13px;
  font-weight: 800;
  color: var(--bakelite-dark);
  background: #FFFFFF;
  border: 2px solid var(--voltage-orange);
  padding: 8px 20px;
  border-radius: 999px;
  display: table;
  margin: -32px auto 36px;
  box-shadow: var(--shadow-switchboard);
}

.reviews-grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}

.review-card {
  padding: 28px 24px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.review-text {
  font-size: 14.5px;
  color: var(--bakelite-dark);
  line-height: 1.75;
  margin-bottom: 20px;
}

.review-user {
  display: flex;
  align-items: center;
  gap: 12px;
  padding-top: 14px;
  border-top: 1.5px solid var(--bakelite-border);
}

.review-avatar {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  background: var(--voltage-orange);
  color: #FFF;
  font-weight: 800;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* ==========================================================================
   11. 安全
   六块说明：加密、隐私政策、内容安全、未成年人保护、用户协议、举报入口。
   做成产品模块，不是一整面法律文。
   ========================================================================== */
.security-grid-6 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.security-module-card {
  padding: 24px 22px;
}

.security-badge {
  display: inline-block;
  padding: 3px 10px;
  font-size: 12px;
  font-weight: 800;
  font-family: var(--font-mono);
  color: #FFF;
  background: var(--bakelite-dark);
  border-left: 3px solid var(--voltage-orange);
  border-radius: 4px;
  margin-bottom: 12px;
}

.security-module-card h3 {
  font-size: 18px;
  font-weight: 900;
  margin-bottom: 8px;
}

.security-module-card p {
  font-size: 13.5px;
  color: var(--bakelite-muted);
  line-height: 1.65;
}

/* ==========================================================================
   12. 常见问题
   四个类别：产品认知、功能使用、下载与多端、安全与隐私。每条回答拆成四步。
   ========================================================================== */
.faq-narrow-wrap {
  max-width: 880px;
  margin: 0 auto;
}

.faq-category-tabs {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
  margin-bottom: 28px;
}

.faq-cat-pill {
  padding: 6px 16px;
  background: #FFFFFF;
  border: 2px solid var(--bakelite-panel);
  border-radius: 6px;
  font-size: 13.5px;
  font-weight: 800;
  color: var(--bakelite-dark);
}

.faq-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.faq-details {
  background: #FFFFFF;
  border: 2px solid var(--bakelite-panel);
  border-left: 7px solid var(--voltage-orange);
  border-radius: 10px;
  box-shadow: var(--shadow-switchboard);
  overflow: hidden;
}

.faq-summary {
  padding: 20px 24px;
  font-size: 16.5px;
  font-weight: 800;
  color: var(--bakelite-dark);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  list-style: none;
}

.faq-summary::-webkit-details-marker {
  display: none;
}

.faq-cat-label {
  font-size: 12px;
  font-weight: 800;
  padding: 3px 10px;
  background: var(--voltage-orange);
  color: #FFF;
  border-radius: 4px;
  margin-right: 10px;
}

.faq-steps-grid {
  padding: 18px 24px 22px;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  border-top: 1.5px dashed var(--bakelite-border);
}

.faq-step-box {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 12px;
  background: var(--bakelite-bg);
  border: 1px solid var(--bakelite-border);
  border-radius: 8px;
  font-size: 13.5px;
  color: var(--bakelite-dark);
}

.step-circle {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--voltage-orange);
  color: #FFF;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 800;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  margin-top: 2px;
}

/* ==========================================================================
   13. 收口与页脚
   末段是「现在就开始使用豆包」，把人送回对话或下载。
   ========================================================================== */
.closing-cta-section {
  background: linear-gradient(135deg, var(--bakelite-dark) 0%, #3A2218 52%, var(--voltage-orange) 100%);
  color: #FFF;
  padding: 88px 0;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.closing-cta-box {
  max-width: 720px;
  margin: 0 auto;
  position: relative;
  z-index: 2;
}

.closing-cta-title {
  font-size: clamp(28px, 4vw, 42px);
  font-weight: 900;
  margin-bottom: 16px;
  color: #FFF;
}

.closing-cta-desc {
  font-size: 16px;
  color: #F4EAE4;
  margin-bottom: 32px;
}

.closing-btn-row {
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
}

.site-footer {
  background: #16191D;
  color: #BDC7D4;
  padding: 64px 0 36px;
  font-size: 14px;
}

.footer-top-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1fr;
  gap: 36px;
  padding-bottom: 40px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.14);
}

.footer-brand-title {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 19px;
  font-weight: 900;
  color: #FFF;
  margin-bottom: 12px;
}

.footer-brand-title img {
  width: 34px;
  height: 34px;
  border-radius: 50%;
}

.footer-col h4 {
  color: var(--voltage-bright);
  font-size: 15px;
  font-weight: 800;
  margin-bottom: 14px;
}

.footer-col ul {
  display: flex;
  flex-direction: column;
  gap: 9px;
}

.footer-col a {
  color: #BDC7D4;
}

.footer-col a:hover {
  color: #FFF;
}

.footer-bottom-bar {
  padding-top: 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 14px;
  font-size: 13px;
  color: #8492A4;
}

/* ==========================================================================
   窄屏底部固定双按钮条：「下载 App」和「开始对话」
   ========================================================================== */
.mobile-fixed-bar {
  display: none;
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 120;
  padding: 10px 16px calc(10px + env(safe-area-inset-bottom));
  background: rgba(226, 230, 236, 0.96);
  backdrop-filter: blur(14px);
  border-top: 2px solid var(--bakelite-panel);
  grid-template-columns: 1fr 1.25fr;
  gap: 12px;
}

.mobile-fixed-bar a {
  padding: 12px 14px;
  border-radius: 999px;
  font-size: 14.5px;
  font-weight: 800;
  text-align: center;
}

.mobile-btn-dl {
  background: #FFFFFF;
  color: var(--bakelite-dark);
  border: 2px solid var(--bakelite-panel);
}

.mobile-btn-chat {
  background: var(--voltage-orange);
  color: #FFF;
}

/* ==========================================================================
   响应式适配 (1080px / 900px / 640px)
   窄屏改成单列堆叠，主按钮拉满宽，底部双按钮一直在。
   ========================================================================== */
@media (max-width: 1080px) {
  .matrix-grid,
  .tech-grid-4,
  .trust-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .scenarios-grid,
  .qa-grid-3,
  .reviews-grid-3,
  .security-grid-6 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 900px) {
  .nav-anchors {
    display: none;
  }
  .download-split {
    grid-template-columns: 1fr;
  }
  .platforms-grid-3 {
    grid-template-columns: repeat(2, 1fr);
  }
  .footer-top-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 640px) {
  body {
    padding-bottom: 74px;
  }
  .ink-bleed-section {
    padding: 60px 0;
  }
  .hero-center-box {
    padding: 28px 18px;
  }
  .hero-cta-group,
  .matrix-grid,
  .scenarios-grid,
  .qa-grid-3,
  .platforms-grid-3,
  .tech-grid-4,
  .reviews-grid-3,
  .security-grid-6,
  .trust-grid,
  .faq-steps-grid,
  .footer-top-grid {
    grid-template-columns: 1fr;
  }
  .hero-input-bar {
    flex-direction: column;
    border-radius: 20px;
    padding: 12px;
    gap: 10px;
  }
  .hero-input-field,
  .hero-embed-btn {
    width: 100%;
  }
  .trust-item {
    border-right: none;
    border-bottom: 1px solid rgba(255, 255, 255, 0.18);
    padding-bottom: 10px;
  }
  .trust-item:last-child {
    border-bottom: none;
  }
  .mobile-fixed-bar {
    display: grid;
  }
}