/* ==========================================================================
   胖虎AI 8095 — 首页（独立样式表）
   --------------------------------------------------------------------------
   设计基调：Apple 风浅色毛玻璃（liquid glass）。
   - 背景是低饱和的浅灰白，上面浮着几团大范围、低透明度的彩色光晕
   - 所有卡片/导航是半透明玻璃：backdrop-filter blur + saturate，
     顶部 1px 高光内边线模拟折射，外侧一层很软的投影模拟悬浮
   - 字体走系统栈（macOS/iOS 即 SF Pro），字距收紧，标题用大字重反差

   这个文件是自包含的：首页不再加载 tailwind CDN / styles.css / app.js。
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. Tokens
   -------------------------------------------------------------------------- */

:root {
  /* 表面 */
  --bg: #f7f8fb;
  --bg-deep: #f1f3f8;
  --glass-fill: rgba(255, 255, 255, 0.62);
  --glass-fill-strong: rgba(255, 255, 255, 0.76);
  --glass-fill-soft: rgba(255, 255, 255, 0.44);
  --glass-edge: rgba(255, 255, 255, 0.72);
  --glass-hairline: rgba(15, 23, 42, 0.07);
  --glass-blur: 28px;
  --glass-saturate: 180%;

  /* 文字 —— 全部经过对比度校验，见文件末尾注释 */
  --ink: #14161c; /* 16.6:1 on --bg */
  --ink-2: #4a5060; /* 8.0:1  on --bg */
  --ink-3: #5f6675; /* 5.9:1  on --bg */
  --ink-on-dark: #ffffff;

  /* 品牌 */
  --brand: #1b2433;
  --brand-soft: rgba(27, 36, 51, 0.06);
  --accent-a: #6f8cff;
  --accent-b: #b58cff;
  --accent-c: #64d2c4;

  /* 主按钮：深海蓝渐变。白字 5.2:1 达 AA，
     比原来的近黑色在浅灰白玻璃底上更跳、也更清新。 */
  --blue: #2563eb;
  --blue-deep: #1d4ed8;
  --blue-darker: #1e40af;
  --blue-soft: rgba(37, 99, 235, 0.08);
  --blue-glow: rgba(37, 99, 235, 0.42);

  /* 拟态：一亮一暗两道方向相反的阴影，模拟从表面「浮起来」 */
  --neu-light: rgba(255, 255, 255, 0.9);
  --neu-dark: rgba(15, 23, 42, 0.1);

  /* 结构 */
  --radius-sm: 14px;
  --radius: 22px;
  --radius-lg: 32px;
  --radius-pill: 999px;

  --shadow-sm: 0 2px 8px rgba(15, 23, 42, 0.05);
  --shadow: 0 18px 40px -18px rgba(15, 23, 42, 0.22), 0 2px 8px rgba(15, 23, 42, 0.04);
  --shadow-lg: 0 40px 90px -30px rgba(15, 23, 42, 0.3), 0 4px 14px rgba(15, 23, 42, 0.05);

  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --nav-h: 68px;
}

/* --------------------------------------------------------------------------
   2. Reset / base
   -------------------------------------------------------------------------- */

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  min-height: 100dvh;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--ink);
  background: var(--bg);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1,
h2,
h3,
h4,
p,
figure {
  margin: 0;
}

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

img,
svg {
  display: block;
  max-width: 100%;
}

button {
  font: inherit;
  color: inherit;
  border: 0;
  background: none;
  cursor: pointer;
}

:focus-visible {
  outline: 2px solid var(--brand);
  outline-offset: 3px;
  border-radius: 6px;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  top: 12px;
  left: 12px;
  z-index: 200;
  padding: 12px 20px;
  border-radius: var(--radius-pill);
  background: #fff;
  box-shadow: var(--shadow);
  font-weight: 600;
  transform: translateY(-160%);
  transition: transform 0.24s var(--ease);
}

.skip-link:focus-visible {
  transform: translateY(0);
}

/* --------------------------------------------------------------------------
   3. 背景光晕
   -------------------------------------------------------------------------- */

.aurora {
  position: fixed;
  inset: 0;
  z-index: -1;
  overflow: hidden;
  background:
    radial-gradient(120% 90% at 50% -10%, #ffffff 0%, rgba(255, 255, 255, 0) 62%),
    linear-gradient(180deg, #fafbfd 0%, var(--bg) 46%, var(--bg-deep) 100%);
}

.aurora span {
  position: absolute;
  display: block;
  border-radius: 50%;
  /* 光晕整体压淡：原来 blur 90 / opacity 0.5，三团叠在一起把整页染成紫蓝，
     长时间看很累。加大模糊半径让边界更散，透明度降到「若隐若现」。 */
  filter: blur(130px);
  opacity: 0.17;
  will-change: transform;
}

.aurora .orb-a {
  top: -14vh;
  left: -6vw;
  width: 46vw;
  height: 46vw;
  min-width: 380px;
  min-height: 380px;
  background: radial-gradient(circle, var(--accent-a) 0%, rgba(111, 140, 255, 0) 70%);
  animation: drift-a 26s var(--ease) infinite alternate;
}

.aurora .orb-b {
  top: 24vh;
  right: -12vw;
  width: 42vw;
  height: 42vw;
  min-width: 340px;
  min-height: 340px;
  background: radial-gradient(circle, var(--accent-b) 0%, rgba(181, 140, 255, 0) 70%);
  opacity: 0.13;
  animation: drift-b 32s var(--ease) infinite alternate;
}

.aurora .orb-c {
  bottom: -18vh;
  left: 28vw;
  width: 40vw;
  height: 40vw;
  min-width: 320px;
  min-height: 320px;
  background: radial-gradient(circle, var(--accent-c) 0%, rgba(100, 210, 196, 0) 70%);
  opacity: 0.11;
  animation: drift-c 38s var(--ease) infinite alternate;
}

@keyframes drift-a {
  to {
    transform: translate3d(8vw, 6vh, 0) scale(1.14);
  }
}

@keyframes drift-b {
  to {
    transform: translate3d(-7vw, 9vh, 0) scale(1.1);
  }
}

@keyframes drift-c {
  to {
    transform: translate3d(6vw, -7vh, 0) scale(1.18);
  }
}

/* --------------------------------------------------------------------------
   4. 玻璃基元
   -------------------------------------------------------------------------- */

.glass {
  position: relative;
  background: var(--glass-fill);
  border: 1px solid var(--glass-hairline);
  border-radius: var(--radius);
  box-shadow:
    var(--shadow),
    inset 0 1px 0 var(--glass-edge);
  -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(var(--glass-saturate));
  backdrop-filter: blur(var(--glass-blur)) saturate(var(--glass-saturate));
}

/* 玻璃顶缘的一道折射高光 */
.glass::before {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  padding: 1px;
  background: linear-gradient(150deg, rgba(255, 255, 255, 0.9), rgba(255, 255, 255, 0) 42%);
  -webkit-mask:
    linear-gradient(#000 0 0) content-box,
    linear-gradient(#000 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  pointer-events: none;
}

@supports not ((backdrop-filter: blur(1px)) or (-webkit-backdrop-filter: blur(1px))) {
  .glass {
    background: rgba(255, 255, 255, 0.92);
  }
}

/* --------------------------------------------------------------------------
   5. 导航
   -------------------------------------------------------------------------- */

.site-nav {
  position: fixed;
  top: calc(14px + env(safe-area-inset-top));
  left: 50%;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
  width: min(1160px, calc(100% - 32px));
  padding: 10px 12px 10px 18px;
  border-radius: var(--radius-pill);
  transform: translateX(-50%);
  transition: box-shadow 0.4s var(--ease), background-color 0.4s var(--ease);
}

.site-nav.is-scrolled {
  background: var(--glass-fill-strong);
  box-shadow:
    var(--shadow-lg),
    inset 0 1px 0 var(--glass-edge);
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  min-height: 44px;
  padding-right: 6px;
  font-weight: 700;
  font-size: 19px;
  letter-spacing: -0.02em;
}

.nav-brand img {
  width: 34px;
  height: 34px;
  border-radius: 50%;
  object-fit: cover;
  box-shadow: 0 0 0 1px rgba(15, 23, 42, 0.08);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
  margin-right: auto;
}

.nav-links a {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 14px;
  border-radius: var(--radius-pill);
  color: var(--ink-2);
  font-size: 15px;
  font-weight: 500;
  transition: color 0.22s var(--ease), background-color 0.22s var(--ease);
}

.nav-links a:hover {
  color: var(--blue-deep);
  background: var(--blue-soft);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 6px;
}

.icon-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  color: var(--ink-2);
  transition: color 0.22s var(--ease), background-color 0.22s var(--ease);
}

.icon-button:hover {
  color: var(--blue-deep);
  background: var(--blue-soft);
}

.icon-button svg {
  width: 20px;
  height: 20px;
}

/* 语言菜单 */
.menu-wrap {
  position: relative;
}

.menu-pop {
  position: absolute;
  top: calc(100% + 10px);
  right: 0;
  z-index: 10;
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 168px;
  padding: 6px;
  border-radius: 16px;
  background: var(--glass-fill-strong);
  border: 1px solid var(--glass-hairline);
  box-shadow: var(--shadow-lg), inset 0 1px 0 var(--glass-edge);
  -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(var(--glass-saturate));
  backdrop-filter: blur(var(--glass-blur)) saturate(var(--glass-saturate));
  transform-origin: top right;
  animation: pop-in 0.2s var(--ease);
}

.menu-pop[hidden] {
  display: none;
}

@keyframes pop-in {
  from {
    opacity: 0;
    transform: scale(0.94) translateY(-6px);
  }
}

.menu-pop button {
  display: flex;
  align-items: center;
  gap: 10px;
  min-height: 44px;
  padding: 0 14px;
  border-radius: 11px;
  color: var(--ink-2);
  font-size: 15px;
  text-align: left;
  transition: background-color 0.18s var(--ease), color 0.18s var(--ease);
}

.menu-pop button:hover {
  color: var(--ink);
  background: rgba(15, 23, 42, 0.05);
}

.menu-pop button[aria-checked="true"] {
  color: var(--ink);
  font-weight: 600;
  background: rgba(15, 23, 42, 0.06);
}

.menu-pop button .tick {
  margin-left: auto;
  opacity: 0;
}

.menu-pop button[aria-checked="true"] .tick {
  opacity: 1;
}

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 46px;
  padding: 0 22px;
  border-radius: var(--radius-pill);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: -0.01em;
  white-space: nowrap;
  transition: transform 0.24s var(--ease), box-shadow 0.24s var(--ease),
    background-color 0.24s var(--ease), color 0.24s var(--ease);
}

.btn svg {
  width: 18px;
  height: 18px;
  flex: none;
}

/* 主按钮：深海蓝渐变 + 拟态浮起。
   顶缘一道内高光模拟受光面，底部一圈蓝色辉光模拟投在玻璃上的色散。 */
.btn-primary {
  color: var(--ink-on-dark);
  background: linear-gradient(180deg, var(--blue) 0%, var(--blue-deep) 100%);
  box-shadow:
    0 12px 28px -10px var(--blue-glow),
    0 2px 6px rgba(29, 78, 216, 0.25),
    inset 0 1px 0 rgba(255, 255, 255, 0.28),
    inset 0 -1px 0 rgba(15, 23, 42, 0.14);
}

.btn-primary:hover {
  transform: translateY(-1.5px);
  background: linear-gradient(180deg, #3b82f6 0%, var(--blue) 100%);
  box-shadow:
    0 20px 38px -12px var(--blue-glow),
    0 3px 8px rgba(29, 78, 216, 0.28),
    inset 0 1px 0 rgba(255, 255, 255, 0.34),
    inset 0 -1px 0 rgba(15, 23, 42, 0.14);
}

/* 按下去时反转阴影方向 —— 拟态里的「按进表面」 */
.btn-primary:active {
  transform: translateY(0) scale(0.985);
  background: linear-gradient(180deg, var(--blue-deep) 0%, var(--blue-darker) 100%);
  box-shadow:
    0 3px 10px -4px var(--blue-glow),
    inset 0 2px 5px rgba(15, 23, 42, 0.32),
    inset 0 -1px 0 rgba(255, 255, 255, 0.14);
}

/* 次按钮：玻璃拟态 —— 上亮下暗两道外阴影把它从背景里托起来 */
.btn-ghost {
  color: var(--blue-deep);
  background: var(--glass-fill-strong);
  border: 1px solid rgba(37, 99, 235, 0.16);
  box-shadow:
    -4px -4px 12px var(--neu-light),
    6px 8px 20px -8px var(--neu-dark),
    inset 0 1px 0 var(--glass-edge);
  -webkit-backdrop-filter: blur(18px) saturate(var(--glass-saturate));
  backdrop-filter: blur(18px) saturate(var(--glass-saturate));
}

.btn-ghost:hover {
  transform: translateY(-1.5px);
  border-color: rgba(37, 99, 235, 0.3);
  background: rgba(255, 255, 255, 0.88);
  box-shadow:
    -6px -6px 16px var(--neu-light),
    10px 14px 28px -10px var(--neu-dark),
    inset 0 1px 0 var(--glass-edge);
}

.btn-ghost:active {
  transform: translateY(0) scale(0.985);
  box-shadow:
    inset 3px 3px 8px rgba(15, 23, 42, 0.09),
    inset -3px -3px 8px rgba(255, 255, 255, 0.9);
}

.btn-lg {
  min-height: 54px;
  padding: 0 30px;
  font-size: 16.5px;
}

/* --------------------------------------------------------------------------
   6. 布局
   -------------------------------------------------------------------------- */

.wrap {
  width: min(1160px, calc(100% - 40px));
  margin: 0 auto;
}

.section {
  padding: clamp(72px, 10vw, 132px) 0;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 15px 7px 11px;
  border-radius: var(--radius-pill);
  background: var(--glass-fill);
  border: 1px solid var(--glass-hairline);
  box-shadow: inset 0 1px 0 var(--glass-edge);
  color: var(--ink-2);
  font-size: 13.5px;
  font-weight: 600;
  letter-spacing: 0.01em;
  -webkit-backdrop-filter: blur(16px) saturate(var(--glass-saturate));
  backdrop-filter: blur(16px) saturate(var(--glass-saturate));
}

.eyebrow .dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--blue);
  box-shadow: 0 0 0 4px var(--blue-soft);
}

/* --------------------------------------------------------------------------
   7. Hero
   -------------------------------------------------------------------------- */

.hero {
  position: relative;
  /* 下边距收紧：下面 .section 自带 72~132px 上边距，叠起来会留一大片空 */
  padding: calc(var(--nav-h) + clamp(48px, 8vw, 92px)) 0 clamp(16px, 2.5vw, 34px);
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.02fr) minmax(0, 0.98fr);
  align-items: center;
  gap: clamp(36px, 5vw, 72px);
}

.hero h1 {
  margin: 22px 0 20px;
  font-family: var(--font-display);
  font-size: clamp(40px, 5.6vw, 68px);
  line-height: 1.06;
  font-weight: 700;
  letter-spacing: -0.035em;
}

.hero h1 .accent {
  background: linear-gradient(96deg, #4a5f9e 0%, #7a5fb8 48%, #3f9d92 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero p.lede {
  max-width: 34em;
  color: var(--ink-2);
  font-size: clamp(16.5px, 1.35vw, 18.5px);
  line-height: 1.66;
}

.hero-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 34px;
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 18px;
  margin-top: 34px;
  color: var(--ink-3);
  font-size: 13.5px;
}

.hero-meta .sep {
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: currentColor;
  opacity: 0.4;
}

/* --------------------------------------------------------------------------
   hero 视觉：会自己敲代码的终端
   -------------------------------------------------------------------------- */

.hero-visual {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.code-card {
  overflow: hidden;
  border-radius: var(--radius-lg);
  box-shadow:
    var(--shadow-lg),
    -6px -6px 18px rgba(255, 255, 255, 0.7),
    inset 0 1px 0 var(--glass-edge);
}

/* 顶部条：macOS 风格的三个灯 + 文件名 + 状态徽标 */
/* 三个灯靠左、文件名居中、状态徽标靠右 —— 和真实终端窗口一致。
   用 grid 三列而不是 flex：中间那列拿到剩余空间，标题才是真的居中，
   不会因为左右两边宽度不一样被推偏。 */
.code-bar {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  border-bottom: 1px solid var(--glass-hairline);
  background: rgba(255, 255, 255, 0.42);
}

.code-bar .dots {
  display: inline-flex;
  gap: 6px;
}

.code-bar .dots i {
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: #d8dce4;
  box-shadow: inset 0 1px 1px rgba(15, 23, 42, 0.14);
}

.code-bar .dots i:nth-child(1) {
  background: #f2a5a0;
}

.code-bar .dots i:nth-child(2) {
  background: #f2d69b;
}

.code-bar .dots i:nth-child(3) {
  background: #a8ddb4;
}

.code-file {
  color: var(--ink-3);
  font-family: var(--font-mono);
  font-size: 12.5px;
  text-align: center;
}

.code-badge {
  justify-self: end;
  padding: 3px 10px;
  border-radius: var(--radius-pill);
  background: var(--blue-soft);
  color: var(--blue-deep);
  font-size: 11.5px;
  font-weight: 600;
  letter-spacing: 0.02em;
  transition: background-color 0.3s var(--ease), color 0.3s var(--ease);
}

.code-badge.is-live {
  background: rgba(14, 165, 233, 0.14);
  color: #0369a1;
}

.code-badge.is-done {
  background: rgba(14, 125, 55, 0.12);
  color: #0e7d37;
}

/* 代码区。高度锁死，避免打字过程中整页高度跳动。 */
.code-body {
  position: relative;
  margin: 0;
  padding: 18px 20px;
  min-height: 268px;
  overflow: hidden;
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.85;
  white-space: pre-wrap;
  word-break: break-word;
  tab-size: 2;
}

.code-body code {
  font: inherit;
  color: var(--ink-2);
}

/* 语法着色 —— 全部在浅底上验过对比度 */
.code-body .t-cmd {
  color: #0e7d37;
  font-weight: 600;
} /* 5.2:1 */

.code-body .t-url {
  color: var(--blue-deep);
} /* 6.3:1 */

.code-body .t-flag {
  color: #7c3aed;
} /* 5.6:1 */

.code-body .t-str {
  color: #b45309;
} /* 4.9:1 */

.code-body .t-key {
  color: #0f766e;
} /* 4.9:1 */

.code-body .t-punc {
  color: var(--ink-3);
}

.caret {
  display: inline-block;
  width: 7px;
  height: 15px;
  margin-left: 1px;
  vertical-align: text-bottom;
  border-radius: 1px;
  background: var(--blue);
  animation: caret-blink 1.05s steps(1) infinite;
}

@keyframes caret-blink {
  0%,
  49% {
    opacity: 1;
  }
  50%,
  100% {
    opacity: 0;
  }
}

/* 返回气泡 */
.reply-card {
  display: flex;
  align-items: flex-start;
  gap: 11px;
  padding: 14px 16px;
  border-radius: var(--radius);
  box-shadow:
    var(--shadow),
    -4px -4px 12px rgba(255, 255, 255, 0.65),
    inset 0 1px 0 var(--glass-edge);
  animation: reply-in 0.45s var(--ease);
}

.reply-card[hidden] {
  display: none;
}

@keyframes reply-in {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
}

.reply-avatar {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex: none;
  width: 28px;
  height: 28px;
  border-radius: 9px;
  background: linear-gradient(150deg, var(--blue) 0%, var(--blue-deep) 100%);
  color: #fff;
  box-shadow: 0 6px 14px -6px var(--blue-glow);
}

.reply-avatar svg {
  width: 15px;
  height: 15px;
}

.reply-text {
  padding-top: 3px;
  color: var(--ink-2);
  font-size: 14.2px;
  line-height: 1.65;
}

.reply-text::after {
  content: "";
  display: inline-block;
  width: 6px;
  height: 13px;
  margin-left: 2px;
  vertical-align: text-bottom;
  border-radius: 1px;
  background: var(--blue);
  opacity: 0;
  animation: caret-blink 1.05s steps(1) infinite;
}

.reply-card.is-typing .reply-text::after {
  opacity: 1;
}

.hero-visual .float-chip {
  position: absolute;
  display: flex;
  align-items: center;
  gap: 9px;
  padding: 11px 15px;
  border-radius: var(--radius-pill);
  background: var(--glass-fill-strong);
  border: 1px solid var(--glass-hairline);
  box-shadow: var(--shadow), inset 0 1px 0 var(--glass-edge);
  font-size: 13px;
  font-weight: 600;
  white-space: nowrap;
  -webkit-backdrop-filter: blur(20px) saturate(var(--glass-saturate));
  backdrop-filter: blur(20px) saturate(var(--glass-saturate));
}

.hero-visual .float-chip svg {
  width: 16px;
  height: 16px;
  color: var(--ink-2);
}

.hero-visual .chip-1 {
  top: 12%;
  left: -7%;
  animation: bob 7s ease-in-out infinite;
}

.hero-visual .chip-2 {
  right: -6%;
  bottom: 6%;
  animation: bob 8.5s ease-in-out infinite reverse;
}

@keyframes bob {
  0%,
  100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-9px);
  }
}

/* --------------------------------------------------------------------------
   8. 特性卡片
   -------------------------------------------------------------------------- */

.section-head {
  max-width: 660px;
  margin: 0 0 clamp(36px, 4.4vw, 60px);
}

.section-head h2 {
  margin: 18px 0 14px;
  font-family: var(--font-display);
  font-size: clamp(28px, 3.4vw, 42px);
  line-height: 1.16;
  font-weight: 700;
  letter-spacing: -0.028em;
}

.section-head p {
  color: var(--ink-2);
  font-size: clamp(15.5px, 1.2vw, 17px);
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(276px, 1fr));
  gap: 18px;
}

.feature {
  padding: clamp(26px, 2.6vw, 34px);
  border-radius: var(--radius-lg);
  transition: transform 0.5s var(--ease), box-shadow 0.5s var(--ease);
}

.feature:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg), inset 0 1px 0 var(--glass-edge);
}

/* 图标底座用拟态：微微凸起的圆角方块 */
.feature .chip {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  margin-bottom: 20px;
  border-radius: 15px;
  background: linear-gradient(150deg, rgba(255, 255, 255, 0.96), rgba(233, 239, 252, 0.6));
  border: 1px solid rgba(37, 99, 235, 0.12);
  box-shadow:
    -3px -3px 8px var(--neu-light),
    5px 6px 14px -6px var(--neu-dark),
    inset 0 1px 0 rgba(255, 255, 255, 0.95);
  color: var(--blue-deep);
}

.feature .chip svg {
  width: 23px;
  height: 23px;
}

.feature h3 {
  margin-bottom: 10px;
  font-size: 19.5px;
  font-weight: 650;
  letter-spacing: -0.018em;
}

.feature p {
  color: var(--ink-2);
  font-size: 15.2px;
  line-height: 1.66;
}

/* 数据条 */
.stat-strip {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(190px, 1fr));
  gap: 1px;
  overflow: hidden;
  border-radius: var(--radius-lg);
  background: var(--glass-hairline);
}

.stat-strip .stat {
  padding: clamp(24px, 2.6vw, 34px);
  background: var(--glass-fill);
  -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(var(--glass-saturate));
  backdrop-filter: blur(var(--glass-blur)) saturate(var(--glass-saturate));
}

.stat-strip .stat strong {
  display: block;
  font-family: var(--font-display);
  font-size: clamp(24px, 2.6vw, 32px);
  font-weight: 700;
  letter-spacing: -0.03em;
}

.stat-strip .stat span {
  display: block;
  margin-top: 5px;
  color: var(--ink-3);
  font-size: 14px;
}

/* --------------------------------------------------------------------------
   9. CTA
   -------------------------------------------------------------------------- */

.cta-slab {
  position: relative;
  overflow: hidden;
  padding: clamp(44px, 6vw, 80px) clamp(24px, 5vw, 64px);
  border-radius: var(--radius-lg);
  text-align: center;
  box-shadow: var(--shadow-lg), inset 0 1px 0 var(--glass-edge);
}

.cta-slab::after {
  content: "";
  position: absolute;
  inset: -40% -10% auto;
  height: 130%;
  background: radial-gradient(60% 60% at 50% 0%, rgba(111, 140, 255, 0.18), transparent 70%);
  pointer-events: none;
}

.cta-slab > * {
  position: relative;
  z-index: 1;
}

.cta-slab h2 {
  margin: 20px auto 16px;
  max-width: 16em;
  font-family: var(--font-display);
  font-size: clamp(28px, 3.8vw, 46px);
  line-height: 1.13;
  font-weight: 700;
  letter-spacing: -0.03em;
}

.cta-slab p {
  max-width: 40em;
  margin: 0 auto 32px;
  color: var(--ink-2);
  font-size: clamp(15.5px, 1.2vw, 17px);
}

/* --------------------------------------------------------------------------
   10. 页脚
   -------------------------------------------------------------------------- */

.site-footer {
  padding: 44px 0 calc(44px + env(safe-area-inset-bottom));
  border-top: 1px solid var(--glass-hairline);
}

.footer-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.footer-brand strong {
  display: block;
  font-size: 16px;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.footer-brand span {
  display: block;
  margin-top: 4px;
  color: var(--ink-3);
  font-size: 13.5px;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
}

.footer-links a {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 12px;
  border-radius: var(--radius-pill);
  color: var(--ink-3);
  font-size: 14px;
  transition: color 0.22s var(--ease), background-color 0.22s var(--ease);
}

.footer-links a:hover {
  color: var(--ink);
  background: var(--brand-soft);
}

/* --------------------------------------------------------------------------
   11. 入场动画
   -------------------------------------------------------------------------- */

/* 只有在 JS 确认可用（<html class="js">）时才让元素以隐藏态起步。
   否则脚本一挂，整页内容就永久 opacity:0 —— 什么都看不见。 */
html.js .reveal {
  opacity: 0;
  transform: translateY(26px);
  transition: opacity 0.9s var(--ease), transform 0.9s var(--ease);
  will-change: opacity, transform;
}

html.js .reveal.is-in {
  opacity: 1;
  transform: none;
}

/* --------------------------------------------------------------------------
   12. 响应式
   -------------------------------------------------------------------------- */

@media (max-width: 980px) {
  .hero-grid {
    grid-template-columns: minmax(0, 1fr);
    gap: 44px;
  }

  .hero-visual {
    order: -1;
    max-width: 560px;
    margin: 0 auto;
  }

  .nav-links {
    display: none;
  }
}

@media (max-width: 720px) {
  .site-nav {
    width: calc(100% - 20px);
    padding: 8px 10px 8px 14px;
    background: var(--glass-fill-strong);
    box-shadow: var(--shadow), inset 0 1px 0 var(--glass-edge);
  }

  .nav-brand {
    font-size: 17px;
  }

  .nav-brand img {
    width: 30px;
    height: 30px;
  }

  .hero-cta .btn {
    flex: 1 1 100%;
  }

  .hero-visual .float-chip {
    display: none;
  }
}

@media (max-width: 480px) {
  body {
    font-size: 15.5px;
  }

  .wrap {
    width: calc(100% - 28px);
  }

  .section {
    padding: 64px 0;
  }

  .hero h1 {
    font-size: 36px;
    letter-spacing: -0.03em;
  }

  .feature {
    padding: 24px;
  }

  .code-body {
    min-height: 232px;
    padding: 14px 15px;
    font-size: 11.8px;
    line-height: 1.75;
  }

  .reply-text {
    font-size: 13.4px;
  }

  .cta-slab {
    padding: 40px 22px;
  }

  .footer-row {
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (max-width: 380px) {
  .hero h1 {
    font-size: 31px;
  }

  .nav-brand span {
    display: none;
  }
}

/* --------------------------------------------------------------------------
   13. 动效偏好
   -------------------------------------------------------------------------- */

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

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

/* 高对比度偏好：把玻璃换成实心，保证文字始终可读 */
@media (prefers-contrast: more) {
  .glass,
  .stat-strip .stat,
  .menu-pop,
  .eyebrow,
  .btn-ghost {
    background: #fff;
    -webkit-backdrop-filter: none;
    backdrop-filter: none;
  }

  :root {
    --glass-hairline: rgba(15, 23, 42, 0.28);
    --ink-2: #353c4a;
    --ink-3: #454c5b;
  }
}

/* --------------------------------------------------------------------------
   对比度校验（相对 --bg #f2f3f7 或玻璃之上的等效底色 ≈ #f7f8fb）
     --ink   #14161c  → 16.4:1  ✓ AAA
     --ink-2 #4a5060  →  7.8:1  ✓ AAA
     --ink-3 #5f6675  →  5.7:1  ✓ AA
     白字 on --brand #1b2433 → 15.1:1 ✓ AAA
   -------------------------------------------------------------------------- */