/* ==========================================================================
   Prelook landing — 设计令牌 + 布局
   结构参考 yuumi.coldstoneboy.cn：令牌驱动、深浅双主题、卡片网格。
   ========================================================================== */

:root {
  color-scheme: light;

  /* 主色调 */
  --primary: #4f6bf6;
  --primary-hover: #3f5ae8;
  --primary-light: rgba(79, 107, 246, 0.1);
  --primary-shadow: rgba(79, 107, 246, 0.3);
  --violet: #8b5cf6;

  /* 辅助色 */
  --success: #16a34a;
  --warning: #f5a623;
  --rating: #f5b342;

  /* 中性色 */
  --bg-primary: #f8f9fb;
  --bg-secondary: #f0f2f5;
  --bg-tertiary: #e8ebf0;
  --text-primary: #1a1d23;
  --text-secondary: #4a5568;
  --text-tertiary: #8899a6;
  --border: #e2e6ea;

  /* 渐变与阴影（都带主色，避免灰扑扑） */
  --gradient-1: linear-gradient(135deg, #4f6bf6 0%, #8b5cf6 100%);
  --shadow-sm: 0 1px 3px rgba(79, 107, 246, 0.06);
  --shadow-md: 0 4px 12px rgba(79, 107, 246, 0.08);
  --shadow-lg: 0 8px 24px rgba(79, 107, 246, 0.1);
  --shadow-xl: 0 16px 48px rgba(79, 107, 246, 0.12);

  /* 间距 */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --spacing-2xl: 4.5rem;

  /* 圆角 */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.5rem;

  /* 字体：不引外部字体，中文优先落到系统黑体 */
  --font-sans:
    system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", "Noto Sans SC", sans-serif;

  /* 缓动 */
  --ease-out-expo: cubic-bezier(0.16, 1, 0.3, 1);

  /* 供脚本读取 */
  --primary-color: #4f6bf6;
}

[data-theme="dark"] {
  color-scheme: dark;

  --primary: #6d86ff;
  --primary-hover: #8199ff;
  --primary-light: rgba(109, 134, 255, 0.14);
  --primary-shadow: rgba(0, 0, 0, 0.5);

  --bg-primary: #111318;
  --bg-secondary: #1a1d23;
  --bg-tertiary: #23272e;
  --text-primary: #edf0f5;
  --text-secondary: #b0b8c4;
  --text-tertiary: #6a7a8a;
  --border: #2d333b;

  --gradient-1: linear-gradient(135deg, #6d86ff 0%, #a78bfa 100%);
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.2);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.25);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.3);
  --shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.35);

  --primary-color: #6d86ff;
}

/* ---------- 基础重置 ---------- */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

/* 锚点跳转时避开固定导航栏 */
[id] {
  scroll-margin-top: 80px;
}

:focus-visible {
  outline: 2px solid var(--primary-color);
  outline-offset: 2px;
}

body {
  font-family: var(--font-sans);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

a {
  text-decoration: none;
  color: inherit;
}

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

button {
  cursor: pointer;
  border: none;
  background: none;
  font-family: inherit;
}

::selection {
  background: var(--primary-light);
  color: var(--primary);
}

/* 噪声纹理：给纯色背景一点颗粒，深色下同样成立 */
body::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 9999;
  pointer-events: none;
  opacity: 0.025;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)'/%3E%3C/svg%3E");
  background-repeat: repeat;
  background-size: 256px 256px;
}

/* ---------- 通用 ---------- */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

.gradient-text {
  background: var(--gradient-1);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

/* 滚动入场 */
.reveal {
  opacity: 0;
  transform: translateY(28px);
  transition:
    opacity 0.6s var(--ease-out-expo),
    transform 0.6s var(--ease-out-expo);
  transition-delay: var(--reveal-delay, 0ms);
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* ---------- 导航栏 ---------- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(248, 249, 251, 0.82);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
}

[data-theme="dark"] .navbar {
  background: rgba(17, 19, 24, 0.82);
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--spacing-md);
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
  height: 64px;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  flex: none;
}

.nav-brand .logo {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
}

.brand-name {
  font-size: 1.25rem;
  font-weight: 700;
  background: var(--gradient-1);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

.nav-menu {
  display: flex;
  gap: var(--spacing-lg);
}

.nav-link {
  position: relative;
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: color 0.2s ease;
}

.nav-link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -6px;
  height: 2px;
  border-radius: 2px;
  background: var(--primary);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.2s ease;
}

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

.nav-link.active::after {
  transform: scaleX(1);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  flex: none;
}

.theme-toggle,
.lang-toggle {
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  transition:
    background 0.2s ease,
    color 0.2s ease;
}

.theme-toggle {
  width: 40px;
}

.lang-toggle {
  min-width: 40px;
  padding: 0 10px;
  font-size: 0.8125rem;
  font-weight: 600;
}

.theme-toggle:hover,
.lang-toggle:hover {
  background: var(--bg-tertiary);
  color: var(--primary);
}

.theme-toggle svg {
  width: 20px;
  height: 20px;
}

.icon-moon {
  display: none;
}

[data-theme="dark"] .icon-sun {
  display: none;
}

[data-theme="dark"] .icon-moon {
  display: block;
}

/* ---------- 按钮 ---------- */
.btn {
  position: relative;
  overflow: hidden;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-xs);
  padding: 0.625rem 1.25rem;
  font-size: 0.9375rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  transition:
    transform 0.2s ease,
    box-shadow 0.2s ease,
    background 0.2s ease,
    border-color 0.2s ease,
    color 0.2s ease;
}

.btn:active {
  transform: scale(0.97);
}

.btn .ripple {
  position: absolute;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.45);
  transform: scale(0);
  animation: btn-ripple 0.6s ease-out forwards;
  pointer-events: none;
  z-index: 2;
}

@keyframes btn-ripple {
  to {
    transform: scale(1);
    opacity: 0;
  }
}

.btn-primary {
  background: var(--gradient-1);
  color: #fff;
  box-shadow: 0 4px 14px var(--primary-shadow);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px var(--primary-shadow);
}

.btn-outline {
  background: var(--bg-primary);
  border: 1px solid var(--border);
  color: var(--text-primary);
}

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

/* ---------- 英雄区域 ---------- */
.hero {
  position: relative;
  display: flex;
  align-items: center;
  padding: 128px 0 72px;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  z-index: -1;
  background: linear-gradient(180deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
}

.gradient-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(90px);
}

.orb-1 {
  width: 460px;
  height: 460px;
  background: rgba(79, 107, 246, 0.3);
  top: -150px;
  right: -60px;
}

.orb-2 {
  width: 380px;
  height: 380px;
  background: rgba(139, 92, 246, 0.24);
  bottom: -140px;
  left: -90px;
}

.grid-pattern {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(79, 107, 246, 0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(79, 107, 246, 0.045) 1px, transparent 1px);
  background-size: 50px 50px;
  mask-image: radial-gradient(70% 60% at 50% 40%, #000 20%, transparent 100%);
  -webkit-mask-image: radial-gradient(70% 60% at 50% 40%, #000 20%, transparent 100%);
}

.hero-container {
  display: grid;
  grid-template-columns: 1.05fr 1fr;
  gap: var(--spacing-2xl);
  align-items: center;
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

.hero-title {
  /* Ten full-width glyphs at the 4.4vw ramp: the cap must keep the whole
     one-line title inside the hero's text column (~553px on wide screens).
     3.5rem × 10 chars ≈ 554px — exactly one pixel over, which is why it broke
     into two balanced lines on large monitors. */
  font-size: clamp(2.25rem, 4.4vw, 3.25rem);
  font-weight: 800;
  line-height: 1.12;
  margin-bottom: var(--spacing-md);
  letter-spacing: -0.01em;
  text-wrap: balance;
}

.hero-description {
  font-size: 1.125rem;
  color: var(--text-secondary);
  margin-bottom: var(--spacing-lg);
  max-width: 32rem;
}

/* 安装入口就在 hero 里。两列而不是一行四颗：hero 的文字栏只有 ~557px，
   一行塞不下四颗带图标的按钮。max-width 是给单列后的平板准备的，
   否则每颗会被拉到半屏宽。 */
.hero-actions {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.625rem;
  max-width: 560px;
  margin-inline: auto;
  /* Gap used to come from .hero-stats' bottom margin above; with the stats
     removed this needs its own spacing. */
  margin-top: var(--spacing-xl);
}

/* 四个入口等权：Chrome 不做强调，避免暗示"只该装 Chrome" */
.install-btn {
  gap: 0.625rem;
  padding: 0.75rem 1rem;
  font-size: 0.9375rem;
  font-weight: 600;
  /* 两列并排时"Firefox 安装"最长，折行会把它顶成两行高 */
  white-space: nowrap;
  background: var(--bg-primary);
  border: 1px solid var(--border);
  color: var(--text-primary);
}

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

/* 前三颗挂浏览器官方多色 logo，第四颗是内联的"外链"线性图标 */
.browser-logo {
  width: 22px;
  height: 22px;
  flex: none;
}

/* 英雄区域右侧的产品示意 */
.hero-visual {
  display: flex;
  justify-content: center;
  align-items: center;
}

.app-preview {
  position: relative;
  width: 100%;
  max-width: 520px;
}

/* 录屏后面垫一层柔光，免得它像一块贴上去的白色方块 */
.app-preview::before {
  content: "";
  position: absolute;
  inset: -8% -4%;
  background: radial-gradient(closest-side, rgba(79, 107, 246, 0.3), transparent 72%);
  filter: blur(30px);
  pointer-events: none;
}

.demo-frame {
  position: relative;
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  background: var(--bg-primary);
  box-shadow: var(--shadow-xl);
  overflow: hidden;
}

/* 宽高属性自带 928×700 的宽高比，元数据到位前也占得住位置。
   录屏内容永远是浅色页面，所以它不参与深浅主题切换。 */
.demo-video {
  display: block;
  width: 100%;
  height: auto;
}

.demo-toggle {
  position: absolute;
  right: 12px;
  bottom: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  padding: 0;
  /* 固定浅色而不取主题令牌：它压在白色录屏上，深色主题里跟着变深就糊了 */
  color: #4a5160;
  background: rgba(255, 255, 255, 0.82);
  border: 1px solid rgba(15, 23, 42, 0.1);
  border-radius: 9999px;
  box-shadow: 0 2px 8px rgba(15, 23, 42, 0.16);
  backdrop-filter: blur(6px);
  cursor: pointer;
  opacity: 0.72;
  transition:
    opacity 0.2s ease,
    transform 0.2s ease;
}

.demo-toggle:hover,
.demo-toggle:focus-visible {
  opacity: 1;
}

.demo-toggle svg {
  width: 16px;
  height: 16px;
  fill: currentColor;
}

/* 正在播放时给的是"暂停"图标，暂停时换成"播放"图标 */
.demo-toggle .icon-play {
  display: none;
}

.demo-toggle[data-paused="true"] .icon-play {
  display: block;
}

.demo-toggle[data-paused="true"] .icon-pause {
  display: none;
}

/* ---------- 区块标题 ---------- */
section {
  padding: var(--spacing-2xl) 0;
}

.section-header {
  text-align: center;
  margin-bottom: var(--spacing-xl);
}

.section-tag {
  display: inline-block;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--primary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--spacing-xs);
}

.section-title {
  font-size: clamp(1.75rem, 3vw, 2.5rem);
  font-weight: 700;
  margin-bottom: var(--spacing-xs);
  text-wrap: balance;
}

.section-subtitle {
  font-size: 1.0625rem;
  color: var(--text-secondary);
  max-width: 44rem;
  margin: 0 auto;
}

/* ---------- 功能特性 ---------- */
.features {
  background: var(--bg-secondary);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--spacing-md);
}

.feature-card {
  position: relative;
  background: var(--bg-primary);
  padding: var(--spacing-lg);
  border-radius: var(--radius-xl);
  border: 1px solid var(--border);
  transition:
    transform 0.25s ease,
    box-shadow 0.25s ease,
    border-color 0.25s ease;
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--primary);
}

.feature-card.featured {
  border-color: var(--primary);
  background: linear-gradient(135deg, var(--bg-primary) 0%, var(--primary-light) 100%);
}

.feature-badge {
  position: absolute;
  top: var(--spacing-md);
  right: var(--spacing-md);
  padding: 0.25rem 0.625rem;
  font-size: 0.75rem;
  font-weight: 600;
  background: var(--primary);
  color: #fff;
  border-radius: 9999px;
}

.feature-icon {
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--primary-light) 0%, rgba(79, 107, 246, 0.04) 100%);
  border-radius: var(--radius-lg);
  margin-bottom: var(--spacing-md);
}

.feature-icon svg {
  width: 24px;
  height: 24px;
  color: var(--primary);
}

.feature-card h3 {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: var(--spacing-xs);
}

.feature-card p {
  font-size: 0.9375rem;
  color: var(--text-secondary);
}

.feature-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: var(--spacing-md);
}

.feature-tags .tag {
  padding: 0.25rem 0.625rem;
  font-size: 0.75rem;
  font-weight: 500;
  background: var(--bg-tertiary);
  color: var(--text-secondary);
  border-radius: var(--radius-sm);
}

/* ---------- 极速原理 ---------- */
.speed {
  background: var(--bg-primary);
}

.steps-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--spacing-md);
}

.step-card {
  position: relative;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: var(--spacing-lg);
  transition:
    transform 0.25s ease,
    box-shadow 0.25s ease,
    border-color 0.25s ease;
}

.step-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--primary);
}

.step-num {
  display: block;
  font-size: 1.875rem;
  font-weight: 800;
  letter-spacing: 0.02em;
  background: var(--gradient-1);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

.step-card h3 {
  font-size: 1.125rem;
  font-weight: 600;
  margin: var(--spacing-xs) 0 var(--spacing-xs);
}

.step-card p {
  font-size: 0.9375rem;
  color: var(--text-secondary);
}

.step-card::after {
  content: "→";
  position: absolute;
  right: -18px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-tertiary);
  font-size: 1.125rem;
}

.step-card:last-child::after {
  content: none;
}

.compare {
  max-width: 660px;
  margin: var(--spacing-xl) auto 0;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: var(--spacing-lg) var(--spacing-md);
}

.compare-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: var(--spacing-sm);
}

.cmp-row {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  margin: 10px 0;
}

.cmp-label {
  flex: none;
  width: 132px;
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.cmp-bar {
  flex: 1;
  height: 18px;
  border-radius: 9999px;
  background: var(--bg-tertiary);
  overflow: hidden;
}

.cmp-bar i {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  height: 100%;
  padding-right: 8px;
  border-radius: 9999px;
  font-style: normal;
  font-size: 0.75rem;
  color: #fff;
}

.cmp-bar.cold i {
  width: 0;
  background: linear-gradient(90deg, #c3cadb, #97a1b8);
  animation: coldfill 4.5s ease-in-out infinite;
}

.cmp-bar.warm i {
  width: 0;
  background: var(--gradient-1);
  animation: warmfill 4.5s ease-out infinite;
}

@keyframes coldfill {
  0% {
    width: 0;
  }
  15% {
    width: 12%;
  }
  85% {
    width: 100%;
  }
  100% {
    width: 100%;
  }
}

@keyframes warmfill {
  0% {
    width: 0;
  }
  6% {
    width: 100%;
  }
  100% {
    width: 100%;
  }
}

.compare-note {
  margin-top: var(--spacing-sm);
  font-size: 0.8125rem;
  color: var(--text-tertiary);
}

/* ---------- 用户评价 ---------- */
.reviews {
  background: var(--bg-secondary);
}

/* 用多栏而不是 grid：卡片高矮不一时能自然排成参考图那种错落的三列 */
.reviews-grid {
  columns: 3;
  column-gap: var(--spacing-md);
}

.review-card {
  break-inside: avoid;
  margin-bottom: var(--spacing-md);
  background: var(--bg-primary);
  border-radius: var(--radius-xl);
  padding: var(--spacing-md);
}

.review-head {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 0.75rem;
}

.review-avatar {
  position: relative;
  width: 44px;
  height: 44px;
  flex: none;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: var(--bg-tertiary);
  color: var(--text-tertiary);
}

.review-avatar .avatar-glyph {
  width: 26px;
  height: 26px;
}

/* 小圆环是和卡片同色的底"挖"出来的，不能用 border，否则两边颜色对不上 */
.review-badge {
  position: absolute;
  right: -3px;
  bottom: -3px;
  width: 20px;
  height: 20px;
  padding: 3px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: var(--bg-secondary);
}

.review-badge img {
  width: 100%;
  height: 100%;
}

.review-who {
  display: flex;
  flex-direction: column;
  gap: 0.125rem;
  min-width: 0;
}

.review-name {
  font-size: 1rem;
  font-weight: 700;
}

.review-stars {
  color: var(--rating);
  font-size: 0.875rem;
  letter-spacing: 0.08em;
  line-height: 1;
}

.review-text {
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--text-secondary);
}

/* ---------- 常见问题 ---------- */
.faq {
  background: var(--bg-secondary);
}

.faq-list {
  max-width: 820px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.faq details {
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-sm) var(--spacing-md);
  transition: border-color 0.2s ease;
}

.faq details[open] {
  border-color: var(--primary);
}

.faq summary {
  cursor: pointer;
  font-weight: 600;
  font-size: 1rem;
  list-style: none;
}

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

.faq summary::after {
  content: "+";
  float: right;
  color: var(--primary);
  font-size: 1.25rem;
  line-height: 1;
  transition: transform 0.2s ease;
}

.faq details[open] summary::after {
  content: "−";
}

.faq details p {
  margin-top: 0.75rem;
  font-size: 0.9375rem;
  color: var(--text-secondary);
}

/* ---------- 收尾 CTA（满幅色带） ---------- */
/* 整段是一个饱和色块，不参与 --bg-* 的深浅交替，所以浅色/深色各写一版渐变：
   深色主题下压暗一档，白字和白色按钮才不至于刺眼。 */
.cta-band {
  background: linear-gradient(135deg, #4f6bf6 0%, #6553f0 55%, #8b5cf6 100%);
  color: #fff;
  overflow: hidden;
}

[data-theme="dark"] .cta-band {
  background: linear-gradient(135deg, #3a4fc4 0%, #4b3ec0 55%, #6638b8 100%);
}

.cta-inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 0.92fr);
  align-items: center;
  gap: var(--spacing-2xl);
}

.cta-badge {
  display: inline-flex;
  align-items: center;
  padding: 0.375rem 0.875rem;
  border-radius: 9999px;
  background: rgba(255, 255, 255, 0.16);
  border: 1px solid rgba(255, 255, 255, 0.3);
  font-size: 0.8125rem;
  font-weight: 500;
}

.cta-title {
  margin-top: var(--spacing-md);
  font-size: clamp(1.75rem, 3.2vw, 2.625rem);
  font-weight: 800;
  line-height: 1.18;
  letter-spacing: -0.02em;
}

.cta-sub {
  margin-top: var(--spacing-sm);
  font-size: 1.0625rem;
  color: rgba(255, 255, 255, 0.84);
}

.cta-actions {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.625rem;
  max-width: 560px;
  margin-top: var(--spacing-lg);
}

/* 色带上固定用白底深字：--bg-primary 在深色主题里是近黑色，压在紫底上像四块补丁 */
.cta-actions .install-btn {
  background: rgba(255, 255, 255, 0.96);
  border-color: transparent;
  color: #1f2333;
}

.cta-actions .install-btn:hover {
  background: #fff;
  border-color: transparent;
  color: #4f6bf6;
}

/* ---------- 色带右侧插画 ---------- */
/* 用「前一层用负 margin 压住后一层」而不是绝对定位：窗口高度由内容决定，
   绝对定位要按内容高度算偏移，改一行骨架线就得重算一次。 */
.cta-art {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
}

.art-win {
  border-radius: 12px;
  overflow: hidden;
  background: #fff;
  box-shadow: 0 18px 42px rgba(12, 16, 40, 0.3);
}

.art-back {
  width: 72%;
  transform: rotate(5deg);
}

.art-front {
  width: 84%;
  align-self: flex-start;
  /* 百分比 margin 按容器宽度算，这里就是"往上压 12% 的容器宽" */
  margin: -12% 0 0 -4%;
  transform: rotate(-3deg);
  z-index: 1;
  box-shadow: 0 26px 56px rgba(12, 16, 40, 0.38);
}

.art-bar {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 9px 11px;
  background: #1f2333;
}

.art-bar > i {
  flex: none;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.3);
}

.art-pill {
  flex: 1;
  height: 8px;
  border-radius: 9999px;
  background: rgba(255, 255, 255, 0.22);
}

/* 预览窗那一条：浅色玻璃 + 主色，跟产品里的窗口标题栏同一个意思 */
.art-bar-preview {
  background: color-mix(in srgb, #4f6bf6 17%, #fff);
  border-bottom: 1px solid rgba(79, 107, 246, 0.26);
}

.art-bar-preview .art-pill {
  background: rgba(31, 35, 51, 0.18);
}

.art-favicon {
  flex: none;
  width: 14px;
  height: 14px;
  border-radius: 4px;
  background: linear-gradient(135deg, #4f6bf6, #a78bfa);
}

.art-btns {
  display: flex;
  gap: 5px;
}

.art-btns i {
  width: 9px;
  height: 9px;
  border-radius: 3px;
  background: rgba(31, 35, 51, 0.18);
}

.art-body {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 16px;
}

.art-line {
  height: 10px;
  border-radius: 5px;
  background: #e9ecf3;
}

.art-line.w60 {
  width: 60%;
}
.art-line.w70 {
  width: 70%;
}
.art-line.w80 {
  width: 80%;
}
.art-line.w85 {
  width: 85%;
}

/* ---------- 页脚 ---------- */
/* 上面那一段是满幅色带，所以这里不再需要 border-top：颜色边界本身就是分界 */
.footer {
  background: var(--bg-primary);
  padding: var(--spacing-2xl) 0 var(--spacing-md);
}

.footer-content {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 2fr);
  align-items: start;
  gap: var(--spacing-2xl);
  margin-bottom: var(--spacing-xl);
}

.footer-brand {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
  max-width: 22rem;
}

.footer-brand-head {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.footer-logo {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
}

.footer-name {
  font-size: 1.375rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--text-primary);
}

.footer-brand p {
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--text-tertiary);
}

/* 四栏等宽平铺，而不是靠 gap 撑开的 flex——栏数变了也不用重算间距 */
.footer-links {
  width: 300px;
  margin-left: auto;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--spacing-lg);
  place-items: end;
}

.footer-column h4 {
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--spacing-md);
}

.footer-column a {
  display: block;
  font-size: 0.9375rem;
  line-height: 1.6;
  color: var(--text-secondary);
  margin-bottom: 0.75rem;
  transition: color 0.2s ease;
}

.footer-column a:hover {
  color: var(--primary);
}

.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--spacing-sm);
  padding-top: var(--spacing-lg);
  border-top: 1px solid var(--border);
  font-size: 0.875rem;
  color: var(--text-tertiary);
}

/* 右下角一组：备案号 + 回到顶部。备案号是硬编码的中文法定标识，没有词条。 */
.footer-meta {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

.footer-filing {
  transition: color 0.2s ease;
}

.footer-filing:hover {
  color: var(--primary);
}

/* Floating back-to-top button: hidden until the user scrolls past the fold,
   then fades in. Fixed to the bottom-right so it never overlaps the nav. */
.to-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--bg-secondary);
  color: var(--text-secondary);
  cursor: pointer;
  opacity: 0;
  pointer-events: none;
  transition:
    opacity 0.25s ease,
    transform 0.25s ease,
    border-color 0.2s ease,
    color 0.2s ease;
  box-shadow: var(--shadow-md);
}
.to-top.is-visible {
  opacity: 1;
  pointer-events: auto;
}
.to-top:hover {
  color: var(--primary);
  border-color: var(--primary);
  transform: translateY(-2px);
}
.to-top svg {
  width: 20px;
  height: 20px;
}

/* ---------- 响应式 ---------- */
@media (max-width: 1080px) {
  .hero-container {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-content {
    order: 1;
  }

  .hero-visual {
    order: 0;
  }

  /* 单列之后视觉不再是"半栏"，可以吃满更多宽度 */
  .app-preview {
    max-width: 620px;
  }

  .hero-description {
    max-width: 100%;
    margin-inline: auto;
  }

  .hero-actions {
    justify-content: center;
  }
  .features-grid,
  .steps-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .reviews-grid {
    columns: 2;
  }

  .step-card::after {
    content: none;
  }
}

@media (max-width: 880px) {
  .nav-menu {
    display: none;
  }
}

/* 色带在窄屏立起来：文案居中、插画挪到下面并收窄。
   断点压到 820px 而不是 960：768–960 这一档还放得下左右两栏，
   提前立起来只会让色带上下空出一大片。 */
@media (max-width: 820px) {
  .cta-inner {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .cta-actions {
    margin-inline: auto;
  }

  .cta-art {
    max-width: 380px;
    width: 100%;
    margin: var(--spacing-lg) auto 0;
    align-self: center;
  }
}

/* 手机上只留色块和按钮：插画会让这一段占掉整整一屏，而这一段的意义就是那四颗按钮 */
@media (max-width: 600px) {
  .cta-art {
    display: none;
  }
}

@media (max-width: 768px) {
  :root {
    --spacing-2xl: 3.5rem;
  }

  /* 手机上演示视频照样留着，只是挪到标题与下载按钮之后：先给结论，再给演示 */
  .hero-visual {
    order: 2;
  }

  .hero {
    padding-top: 108px;
  }

  .features-grid,
  .steps-grid {
    grid-template-columns: 1fr;
  }

  .reviews-grid {
    columns: 1;
  }

  .cmp-row {
    flex-direction: column;
    align-items: stretch;
    gap: 0.25rem;
  }

  .cmp-label {
    width: auto;
  }

  .footer-content {
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
  }

  .footer-links {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: var(--spacing-lg);
  }

  .footer-column {
    min-width: 8rem;
  }

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.5rem;
  }
}

@media (max-width: 520px) {
  .hero-title {
    font-size: 2rem;
  }
}

/* 再窄就只能一行一颗了：两列时每颗只剩 ~140px，装不下"Firefox 安装 + 图标" */
@media (max-width: 380px) {
  .hero-actions {
    grid-template-columns: 1fr;
  }
}

/* ---------- 减少动态效果 ---------- */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }

  .cmp-bar.cold i,
  .cmp-bar.warm i {
    width: 100%;
    animation: none;
  }

  .reveal {
    opacity: 1;
    transform: none;
  }
}