@charset "utf-8";
/* ==========================================================================
   禾下土 · 农业科技小站  /  style.css
   --------------------------------------------------------------------------
   性能预算（2 核 2G · 首屏 < 300KB · 请求数 < 25）
     · 本文件未压缩约 24KB，nginx gzip 后约 6KB
     · 零图片请求：土壤颗粒、光斑、图标、二维码全部由 CSS 渐变 + 内联 SVG 生成
     · 动画只碰 transform / opacity / stroke-dashoffset，均不触发 layout
     · 首屏内容全部为静态 HTML，JS 只做增强（没 JS 也能读完整篇）

   卡顿排查顺序（从先关到后关，已按 GPU 代价排序）
     1. .hero::before / .hero::after 光斑 —— filter:blur + mix-blend-mode，
        移动端 GPU 填充率最贵，先用「省电模式」或删掉这两条伪元素
     2. .cursor-glow 跟随光 —— 每帧一次 transform，只在 hover 设备启用
     3. .vine-line stroke-dashoffset —— 只在首屏入场跑一次 6.5s，之后零重绘
     4. .grain 噪点 —— 静态图层只绘制一次，一般不用管
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. Design tokens
   -------------------------------------------------------------------------- */
:root {
  /* 色板 */
  --soil: #3b2f2a;
  --deep: #1e1a17;
  --bark: #26201c;
  --bark-2: #2f2723;
  --sprout: #7ce07a;
  --moss: #4caf6d;
  --wheat: #e8c46a;
  --cream: #f3efe6;
  --cream-dim: #c4bbb0;
  --cream-mute: #9f958c;

  /* 8px 基准栅格 */
  --s1: 8px;
  --s2: 16px;
  --s3: 24px;
  --s4: 32px;
  --s6: 48px;
  --s8: 64px;
  --s12: 96px;
  --s16: 128px;

  --radius: 6px;
  --radius-lg: 10px;
  --maxw: 1200px;

  /* 字体：标题机械感无衬线，正文系统栈。中文全部显式指定，避免回退成宋体 */
  --font-display: "Space Grotesk", "Archivo", "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", "Source Han Sans SC", "Noto Sans SC", system-ui, sans-serif;
  --font-body: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", "Noto Sans SC",
    sans-serif;

  --ease: cubic-bezier(0.22, 0.85, 0.24, 1);
  --grow: 0; /* 滚动进度 0~1，由 main.js 写入 */
}

/* --------------------------------------------------------------------------
   2. Reset / base
   -------------------------------------------------------------------------- */
*,
*::before,
*::after {
  box-sizing: border-box;
}

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

body {
  margin: 0;
  background: var(--deep);
  color: var(--cream);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  letter-spacing: 0.01em;
  overflow-x: hidden;
  /* 底色：极深的土壤，顶部带一层几乎看不见的褐 */
  background-image: radial-gradient(
      120% 80% at 50% -10%,
      #2a221d 0%,
      rgba(30, 26, 23, 0) 60%
    ),
    radial-gradient(80% 60% at 100% 100%, #241f1b 0%, rgba(30, 26, 23, 0) 55%);
  background-attachment: fixed;
}

h1,
h2,
h3,
h4 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.14;
  letter-spacing: -0.02em;
  margin: 0;
  color: var(--cream);
}

p {
  margin: 0;
}

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

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

ul,
ol {
  margin: 0;
  padding: 0;
  list-style: none;
}

::selection {
  background: var(--sprout);
  color: var(--deep);
}

/* 可见焦点：满足键盘可达 */
:focus-visible {
  outline: 2px solid var(--sprout);
  outline-offset: 3px;
  border-radius: 2px;
}

.skip {
  position: absolute;
  left: -9999px;
  top: 8px;
  z-index: 999;
  padding: 10px 18px;
  background: var(--sprout);
  color: var(--deep);
  font-weight: 600;
  border-radius: var(--radius);
}
.skip:focus {
  left: 16px;
}

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

/* --------------------------------------------------------------------------
   3. 布局骨架
   -------------------------------------------------------------------------- */
.wrap {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 var(--s4);
  position: relative;
}

.section {
  position: relative;
  padding: var(--s16) 0;
}

.section--tight {
  padding: var(--s12) 0;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--s1);
  font-family: var(--font-display);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--moss);
  margin-bottom: var(--s3);
}
.eyebrow::before {
  content: "";
  width: 22px;
  height: 1px;
  background: var(--moss);
  opacity: 0.7;
}

.section-title {
  font-size: clamp(1.75rem, 3.4vw, 2.75rem);
  /* 用 em 而不是 ch：中文一个汉字约等于 1em，22ch 只有 11 个字，
     会把「一半时间在田里，一半时间在屏前」断成孤字 */
  max-width: 20em;
}

.section-sub {
  margin-top: var(--s3);
  max-width: 30em;
  color: var(--cream-dim);
  font-size: 15.5px;
}

/* --------------------------------------------------------------------------
   4. 全站氛围层：颗粒噪点
   —— 140×140 的 SVG feTurbulence 平铺，静态图层只栅格化一次
   -------------------------------------------------------------------------- */
.grain {
  position: fixed;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  opacity: 0.045;
  mix-blend-mode: overlay;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='140' height='140'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.82' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='140' height='140' filter='url(%23n)'/%3E%3C/svg%3E");
}

/* 跟随光：柔光层，transform 由 rAF 驱动，仅 hover 设备 */
.cursor-glow {
  position: fixed;
  left: 0;
  top: 0;
  width: 560px;
  height: 560px;
  margin: -280px 0 0 -280px;
  z-index: 1;
  pointer-events: none;
  border-radius: 50%;
  opacity: 0;
  transition: opacity 0.6s ease;
  mix-blend-mode: screen;
  background: radial-gradient(
    circle,
    rgba(124, 224, 122, 0.13) 0%,
    rgba(76, 175, 109, 0.06) 42%,
    rgba(232, 196, 106, 0.025) 62%,
    rgba(30, 26, 23, 0) 72%
  );
  will-change: transform;
}
.cursor-glow.is-live {
  opacity: 1;
}

/* --------------------------------------------------------------------------
   5. 导航
   -------------------------------------------------------------------------- */
.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(30, 26, 23, 0.72);
  backdrop-filter: saturate(120%) blur(10px);
  -webkit-backdrop-filter: saturate(120%) blur(10px);
  border-bottom: 1px solid rgba(243, 239, 230, 0.08);
  transition: background 0.3s ease, border-color 0.3s ease;
}
.nav.is-stuck {
  background: rgba(24, 21, 18, 0.94);
  border-bottom-color: rgba(243, 239, 230, 0.14);
}

.nav-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 var(--s4);
  height: 64px;
  display: flex;
  align-items: center;
  gap: var(--s4);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: 0.02em;
  font-size: 17px;
}
.brand svg {
  width: 22px;
  height: 22px;
  stroke: var(--sprout);
  fill: none;
  stroke-width: 1.7;
}
.brand-en {
  font-size: 10px;
  font-weight: 500;
  letter-spacing: 0.22em;
  color: var(--cream-mute);
  padding-left: 2px;
  transform: translateY(1px);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--s3);
  margin-left: auto;
  font-size: 14.5px;
}
.nav-links a {
  color: var(--cream-dim);
  padding: 6px 2px;
  position: relative;
  transition: color 0.22s ease;
}
.nav-links a::after {
  content: "";
  position: absolute;
  left: 0;
  right: 100%;
  bottom: 2px;
  height: 1px;
  background: var(--sprout);
  transition: right 0.28s var(--ease);
}
.nav-links a:hover {
  color: var(--cream);
}
.nav-links a:hover::after,
.nav-links a[aria-current="page"]::after {
  right: 0;
}
.nav-links a[aria-current="page"] {
  color: var(--sprout);
}

.eco {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 7px 12px;
  font: inherit;
  font-size: 12.5px;
  color: var(--cream-dim);
  background: transparent;
  border: 1px solid rgba(243, 239, 230, 0.18);
  border-radius: 999px;
  cursor: pointer;
  transition: color 0.2s, border-color 0.2s, background 0.2s;
}
.eco svg {
  width: 13px;
  height: 13px;
  stroke: currentColor;
  fill: none;
  stroke-width: 1.8;
}
.eco:hover {
  color: var(--cream);
  border-color: rgba(124, 224, 122, 0.5);
}
.eco[aria-pressed="true"] {
  color: var(--sprout);
  border-color: rgba(124, 224, 122, 0.55);
  background: rgba(124, 224, 122, 0.08);
}

/* --------------------------------------------------------------------------
   6. Hero —— 藤蔓 / 光斑 / 生长
   -------------------------------------------------------------------------- */
.hero {
  position: relative;
  min-height: clamp(600px, 92vh, 900px);
  display: flex;
  align-items: center;
  overflow: hidden;
  isolation: isolate;
  padding: var(--s16) 0 var(--s12);
}

/* 光斑：两团斜射柔光，26s 极慢漂移
   代价：filter:blur(20px) + mix-blend-mode:screen，填充率开销最大的一个效果 */
.hero::before {
  content: "";
  position: absolute;
  inset: -25% -10%;
  z-index: 0;
  pointer-events: none;
  background: radial-gradient(
      42% 52% at 16% 4%,
      rgba(232, 196, 106, 0.24) 0%,
      rgba(232, 196, 106, 0) 62%
    ),
    radial-gradient(
      34% 40% at 74% 26%,
      rgba(124, 224, 122, 0.15) 0%,
      rgba(124, 224, 122, 0) 60%
    );
  filter: blur(18px);
  mix-blend-mode: screen;
  animation: light-drift 26s ease-in-out infinite alternate;
  will-change: transform;
}

/* 地平线：土壤与光的交界，一条 1px 的暖色渐隐线 */
.hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  background: linear-gradient(
    90deg,
    rgba(232, 196, 106, 0) 0%,
    rgba(232, 196, 106, 0.35) 38%,
    rgba(124, 224, 122, 0.3) 62%,
    rgba(232, 196, 106, 0) 100%
  );
}

@keyframes light-drift {
  0% {
    transform: translate3d(-2%, -1%, 0) scale(1);
  }
  50% {
    transform: translate3d(2.5%, 1.5%, 0) scale(1.06);
  }
  100% {
    transform: translate3d(-1%, 2%, 0) scale(1.02);
  }
}

/* --------------------------------------------------------------------------
   藤蔓生长 + 叶芽萌发
   成本结构：全段只有一个属性会触发重绘（stroke-dashoffset，6.5s 跑一次）；
            跑完之后叶片的 opacity / transform 全在合成层，逐帧零重绘。
   -------------------------------------------------------------------------- */
.vine {
  position: absolute;
  inset: 0;
  z-index: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  opacity: 0.62;
  /* 重绘隔离：藤蔓每帧的脏矩形不会把 hero 的背景纹理和文字一起拉进重绘 */
  contain: paint;
}

.vine-line {
  fill: none;
  stroke: url(#vine-grad);
  stroke-width: 1.5;
  stroke-linecap: round;
  /* pathLength=1000 已把 1759px 的路径归一化，dasharray 写一个值就等于全长，
     不必手算弧长；dashoffset=1000 时整条线正好被推出路径之外 = 完全不可见。
     只设一段 dash，不会像 dasharray:1000 1000 那样出现第二段重复虚线。 */
  stroke-dasharray: 1000;
  stroke-dashoffset: 1000;
  /* forwards：结束后定格在 offset=0，浏览器不再为它生成新的绘制命令 */
  animation: vine-grow 6.5s cubic-bezier(0.45, 0.02, 0.55, 0.98) forwards;
}

/* 起手略慢（顶土），中段匀速，收尾微缓（尖端变细）——生长不是匀速直线 */
@keyframes vine-grow {
  from {
    stroke-dashoffset: 1000;
  }
  to {
    stroke-dashoffset: 0;
  }
}

/* 叶芽：外层 <g transform> 用 SVG 属性定位，不参与动画；
   内层 .bud 只做一次 scale + opacity，0.58s，之后彻底静止 */
.bud {
  fill: rgba(124, 224, 122, 0.92);
  opacity: 0;
  transform: scale(0.12) rotate(-14deg);
  transform-box: fill-box;
  transform-origin: 0% 50%; /* 叶柄落在路径上，叶子由内向外张开 */
  /* 第二个控制点 1.5 > 1 制造轻微过冲：叶子是"弹开"的，不是匀速放大 */
  animation: bud-sprout 0.58s cubic-bezier(0.18, 1.5, 0.42, 1) forwards;
  animation-delay: var(--d, 0s); /* 由路径进度反解出的错峰延迟 */
}

@keyframes bud-sprout {
  to {
    opacity: 1;
    transform: none;
  }
}

/* 叶片呼吸：只转不缩，支点钉在叶柄上，叶子不会从茎上"脱开"。
   transform 走合成层，15 片一起跑也不产生重绘。 */
.bud-blade {
  transform-box: fill-box;
  transform-origin: 0% 50%;
  animation: bud-sway 7s ease-in-out infinite;
  animation-delay: calc(var(--d, 0s) - 0.4s);
}

@keyframes bud-sway {
  0%,
  100% {
    transform: rotate(-1.8deg);
  }
  50% {
    transform: rotate(1.8deg);
  }
}

/* 叶脉：一条 0.9px 的静态曲线，让 28px 的色块读成"叶子"而不是"豆子"。
   不参与任何动画，只在首帧绘制一次。 */
.bud-vein {
  fill: none;
  stroke: rgba(24, 34, 20, 0.55);
  stroke-width: 0.9;
  stroke-linecap: round;
}

.bud--wheat {
  fill: rgba(232, 196, 106, 0.92);
}

.hero-inner {
  position: relative;
  z-index: 2;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 var(--s4);
  width: 100%;
}

.hero h1 {
  font-size: clamp(2.5rem, 6.4vw, 5.25rem);
  line-height: 1.02;
  letter-spacing: -0.035em;
  margin: var(--s3) 0 0;
  max-width: 9.5em;
}
.hero h1 .beam {
  color: var(--sprout);
  position: relative;
}
/* 标题里的一条"生长线"，静态、克制 */
.hero h1 .beam::after {
  content: "";
  position: absolute;
  left: 2px;
  right: 4px;
  bottom: 0.06em;
  height: 2px;
  background: linear-gradient(90deg, var(--sprout), rgba(124, 224, 122, 0.05));
  border-radius: 2px;
}

.hero-lede {
  margin-top: var(--s4);
  max-width: 26em;
  font-size: clamp(15px, 1.35vw, 17.5px);
  line-height: 1.85;
  color: var(--cream-dim);
}
.hero-lede strong {
  color: var(--cream);
  font-weight: 600;
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: var(--s2);
  margin-top: var(--s6);
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 14px 26px;
  border-radius: var(--radius);
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.01em;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.22s var(--ease), background 0.22s ease,
    border-color 0.22s ease, color 0.22s ease;
}
.btn svg {
  width: 16px;
  height: 16px;
  stroke: currentColor;
  fill: none;
  stroke-width: 1.8;
  transition: transform 0.24s var(--ease);
}
.btn:hover svg {
  transform: translateX(3px);
}

.btn--primary {
  background: var(--sprout);
  color: #14210f;
}
.btn--primary:hover {
  background: #8fe98c;
  transform: translateY(-2px);
}

.btn--ghost {
  color: var(--cream);
  border-color: rgba(243, 239, 230, 0.24);
  background: rgba(243, 239, 230, 0.03);
}
.btn--ghost:hover {
  border-color: rgba(232, 196, 106, 0.6);
  color: var(--wheat);
  transform: translateY(-2px);
}

/* Hero 底部微数据 */
.hero-stats {
  display: flex;
  flex-wrap: wrap;
  gap: var(--s6);
  margin-top: var(--s12);
  padding-top: var(--s3);
  border-top: 1px solid rgba(243, 239, 230, 0.1);
  max-width: 620px;
}
.hero-stat b {
  display: block;
  font-family: var(--font-display);
  font-size: 26px;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--cream);
  font-variant-numeric: tabular-nums;
  line-height: 1.2;
}
.hero-stat span {
  font-size: 12.5px;
  color: var(--cream-mute);
  letter-spacing: 0.04em;
}

/* 滚动提示 */
.scroll-hint {
  position: absolute;
  left: 50%;
  bottom: 28px;
  transform: translateX(-50%);
  z-index: 2;
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--cream-mute);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
}
.scroll-hint::after {
  content: "";
  width: 1px;
  height: 34px;
  background: linear-gradient(
    to bottom,
    rgba(124, 224, 122, 0.8),
    rgba(124, 224, 122, 0)
  );
  animation: hint-fall 2.6s ease-in-out infinite;
  transform-origin: top;
}
@keyframes hint-fall {
  0%,
  100% {
    transform: scaleY(0.35);
    opacity: 0.4;
  }
  50% {
    transform: scaleY(1);
    opacity: 1;
  }
}

/* --------------------------------------------------------------------------
   7. 茎干：滚动驱动的竖向主干 + 果实节点
   —— scaleY 由 --grow 控制，纯合成属性，不动 layout
   -------------------------------------------------------------------------- */
.stem {
  position: absolute;
  top: 0;
  bottom: 0;
  left: calc(50% - 636px);
  width: 1px;
  z-index: 0;
  pointer-events: none;
}
.stem-line {
  position: absolute;
  inset: 0;
  transform-origin: top center;
  transform: scaleY(var(--grow));
  background: linear-gradient(
    to bottom,
    rgba(124, 224, 122, 0) 0%,
    rgba(124, 224, 122, 0.5) 8%,
    rgba(76, 175, 109, 0.42) 60%,
    rgba(232, 196, 106, 0.4) 100%
  );
}

/* 果实节点：挂在茎干上，模块进入视口时点亮 */
.node {
  position: absolute;
  left: calc(50% - 636px);
  width: 9px;
  height: 9px;
  margin-left: -4px;
  border-radius: 50%;
  border: 1px solid rgba(124, 224, 122, 0.35);
  background: var(--deep);
  z-index: 0;
  transform: scale(0.4);
  opacity: 0;
  transition: transform 0.6s var(--ease), opacity 0.6s ease,
    background 0.6s ease, box-shadow 0.6s ease;
}
.node.is-in {
  transform: scale(1);
  opacity: 1;
  background: var(--sprout);
  box-shadow: 0 0 0 4px rgba(124, 224, 122, 0.1),
    0 0 18px rgba(124, 224, 122, 0.45);
}

/* --------------------------------------------------------------------------
   8. 进场：模块像果实挂上枝头
   —— 只有 html.js 才隐藏，JS 挂了内容照样可见
   -------------------------------------------------------------------------- */
.js .reveal {
  opacity: 0;
  transform: translateY(26px) rotate(-0.3deg);
}
.js .reveal.is-in {
  opacity: 1;
  transform: translateY(0) rotate(0deg);
  transition: opacity 0.75s var(--ease), transform 0.75s var(--ease);
}
.js .reveal--d1 {
  transition-delay: 0.06s;
}
.js .reveal--d2 {
  transition-delay: 0.12s;
}
.js .reveal--d3 {
  transition-delay: 0.18s;
}

/* --------------------------------------------------------------------------
   9. 生长时间轴（5 阶段）
   -------------------------------------------------------------------------- */
.timeline {
  position: relative;
  margin-top: var(--s12);
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: var(--s3);
}
/* 横向茎：一条从实验田延伸出去的线 */
.timeline::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 22px;
  height: 1px;
  background: linear-gradient(
    90deg,
    rgba(76, 175, 109, 0.55),
    rgba(124, 224, 122, 0.25) 55%,
    rgba(232, 196, 106, 0.4)
  );
}

.tl-item {
  position: relative;
  padding-top: var(--s8);
}
.tl-dot {
  position: absolute;
  top: 16px;
  left: 0;
  width: 13px;
  height: 13px;
  border-radius: 50%;
  border: 1.5px solid var(--moss);
  background: var(--deep);
  transition: background 0.4s ease, box-shadow 0.4s ease;
}
.tl-item:hover .tl-dot {
  background: var(--sprout);
  box-shadow: 0 0 0 5px rgba(124, 224, 122, 0.12);
}

.tl-year {
  font-family: var(--font-display);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.14em;
  color: var(--wheat);
  font-variant-numeric: tabular-nums;
}
.tl-name {
  margin-top: 6px;
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 700;
  color: var(--cream);
  letter-spacing: -0.01em;
}
.tl-desc {
  margin-top: 10px;
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--cream-mute);
}

/* --------------------------------------------------------------------------
   10. 技术矩阵
   -------------------------------------------------------------------------- */
.tech-grid {
  margin-top: var(--s12);
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1px;
  background: rgba(243, 239, 230, 0.09);
  border: 1px solid rgba(243, 239, 230, 0.09);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.tech-card {
  position: relative;
  display: flex;
  flex-direction: column;
  background: var(--deep);
  padding: var(--s4) var(--s4) var(--s6);
  min-height: 232px;
  transition: background 0.3s ease, transform 0.35s var(--ease);
  transform-origin: bottom center;
  will-change: transform;
}
.tech-card::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(
    70% 60% at 50% 0%,
    rgba(124, 224, 122, 0.09),
    rgba(124, 224, 122, 0) 65%
  );
  opacity: 0;
  transition: opacity 0.4s ease;
  pointer-events: none;
}
/* 叶片被风吹的轻摆：角度按列错开，像一阵风扫过去 */
.tech-card:nth-child(4n + 1) {
  --tilt: -1.4deg;
}
.tech-card:nth-child(4n + 2) {
  --tilt: 0.9deg;
}
.tech-card:nth-child(4n + 3) {
  --tilt: -0.7deg;
}
.tech-card:nth-child(4n + 4) {
  --tilt: 1.6deg;
}
.tech-card:hover {
  background: var(--bark);
  transform: rotate(var(--tilt, 1deg)) translateY(-5px);
}
.tech-card:hover::before {
  opacity: 1;
}

.tech-ico {
  width: 34px;
  height: 34px;
  stroke: var(--moss);
  fill: none;
  stroke-width: 1.5;
  stroke-linecap: round;
  stroke-linejoin: round;
  transition: stroke 0.3s ease, transform 0.4s var(--ease);
}
.tech-card:hover .tech-ico {
  stroke: var(--sprout);
  transform: translateY(-2px) rotate(-4deg);
}

.tech-idx {
  position: absolute;
  top: var(--s4);
  right: var(--s4);
  font-family: var(--font-display);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--cream-mute);
  font-variant-numeric: tabular-nums;
}

.tech-name {
  margin-top: var(--s4);
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 700;
  letter-spacing: -0.01em;
}
.tech-desc {
  margin-top: 10px;
  margin-bottom: var(--s3);
  overflow-wrap: break-word;
  font-size: 13.5px;
  line-height: 1.72;
  color: var(--cream-mute);
}
.tech-tag {
  display: inline-block;
  align-self: flex-start; /* 卡片是 flex column，不加这行会被横向拉伸成通栏 */
  margin-top: auto;
  padding: 3px 10px;
  font-size: 11.5px;
  letter-spacing: 0.06em;
  color: var(--wheat);
  border: 1px solid rgba(232, 196, 106, 0.3);
  border-radius: 999px;
}

/* --------------------------------------------------------------------------
   11. 年轮数据
   -------------------------------------------------------------------------- */
.rings {
  margin-top: var(--s12);
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: var(--s3);
}

.ring-card {
  position: relative;
  display: grid;
  place-items: center;
  padding: var(--s2);
  border: 1px solid rgba(243, 239, 230, 0.09);
  border-radius: var(--radius-lg);
  background: linear-gradient(
    180deg,
    rgba(38, 32, 28, 0.7),
    rgba(30, 26, 23, 0.3)
  );
  cursor: default;
  transition: border-color 0.4s ease, background 0.4s ease;
}
.ring-card:hover,
.ring-card:focus-visible {
  border-color: rgba(124, 224, 122, 0.35);
  background: linear-gradient(
    180deg,
    rgba(44, 37, 32, 0.9),
    rgba(30, 26, 23, 0.45)
  );
}

.ring-svg {
  width: 100%;
  max-width: 100%;
  height: auto;
  aspect-ratio: 1;
}
.ring-svg circle {
  fill: none;
  stroke: var(--moss);
  stroke-width: 1;
  opacity: 0.36;
  transform-box: fill-box;
  transform-origin: center;
  transition: transform 0.65s var(--ease), opacity 0.65s ease,
    stroke 0.5s ease;
}
.ring-svg circle:nth-child(2) {
  transition-delay: 0.03s;
}
.ring-svg circle:nth-child(3) {
  transition-delay: 0.06s;
}
.ring-svg circle:nth-child(4) {
  transition-delay: 0.09s;
}
.ring-svg circle:nth-child(5) {
  transition-delay: 0.12s;
}
.ring-svg circle:nth-child(6) {
  transition-delay: 0.15s;
}
.ring-svg circle:nth-child(7) {
  transition-delay: 0.18s;
}

/* 年轮扩张：逐圈放大 + 提亮，像树干在吸水 */
.ring-card:hover .ring-svg circle,
.ring-card:focus-visible .ring-svg circle {
  transform: scale(1.11);
  opacity: 0.8;
  stroke: var(--sprout);
}
.ring-card:hover .ring-svg circle:nth-child(odd),
.ring-card:focus-visible .ring-svg circle:nth-child(odd) {
  stroke: var(--wheat);
}

.ring-meta {
  position: absolute;
  inset: 0;
  display: grid;
  align-content: center;
  justify-items: center;
  text-align: center;
  pointer-events: none;
}
.ring-meta b {
  font-family: var(--font-display);
  font-size: clamp(26px, 2.6vw, 34px);
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--cream);
  font-variant-numeric: tabular-nums;
  line-height: 1;
  transition: color 0.4s ease, transform 0.45s var(--ease);
}
.ring-meta span {
  margin-top: 10px;
  font-size: 12.5px;
  letter-spacing: 0.12em;
  color: var(--cream-mute);
  transition: color 0.4s ease;
}
.ring-card:hover .ring-meta b,
.ring-card:focus-visible .ring-meta b {
  color: var(--sprout);
  transform: scale(1.06);
}
.ring-card:hover .ring-meta span,
.ring-card:focus-visible .ring-meta span {
  color: var(--cream-dim);
}

.rings-note {
  margin-top: var(--s3);
  font-size: 12.5px;
  color: var(--cream-mute);
  max-width: 40em;
}

/* --------------------------------------------------------------------------
   12. 案例田块（图文交替）
   -------------------------------------------------------------------------- */
.case-row {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr);
  gap: var(--s12);
  align-items: center;
  padding: var(--s12) 0;
  border-top: 1px solid rgba(243, 239, 230, 0.08);
}
.case-row:first-of-type {
  border-top: 0;
}
.case-row:nth-of-type(even) .case-figure {
  order: 2;
}

.case-figure {
  position: relative;
  aspect-ratio: 4 / 3;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid rgba(243, 239, 230, 0.1);
  /* 田垄纹理：repeating-linear-gradient 零请求、零解码 */
  background-image: repeating-linear-gradient(
      96deg,
      rgba(243, 239, 230, 0.055) 0px,
      rgba(243, 239, 230, 0.055) 1px,
      rgba(243, 239, 230, 0) 1px,
      rgba(243, 239, 230, 0) 17px
    ),
    radial-gradient(70% 60% at 30% 12%, rgba(232, 196, 106, 0.16), transparent 62%),
    linear-gradient(160deg, #2b241d, #16130f);
}
.case-figure svg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}
.case-badge {
  position: absolute;
  left: var(--s2);
  bottom: var(--s2);
  padding: 6px 12px;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--cream);
  background: rgba(30, 26, 23, 0.82);
  border: 1px solid rgba(243, 239, 230, 0.16);
  border-radius: 999px;
  backdrop-filter: blur(4px);
}

.case-kicker {
  font-family: var(--font-display);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--wheat);
  text-transform: uppercase;
}
.case-title {
  margin-top: var(--s2);
  font-size: clamp(1.4rem, 2.3vw, 1.9rem);
}
.case-body {
  margin-top: var(--s3);
  color: var(--cream-dim);
  font-size: 15px;
  line-height: 1.85;
}
.case-metrics {
  display: flex;
  flex-wrap: wrap;
  gap: var(--s6);
  margin-top: var(--s4);
  padding-top: var(--s3);
  border-top: 1px solid rgba(243, 239, 230, 0.09);
}
.case-metric b {
  display: block;
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 700;
  color: var(--sprout);
  font-variant-numeric: tabular-nums;
  line-height: 1.3;
}
.case-metric span {
  font-size: 12px;
  color: var(--cream-mute);
  letter-spacing: 0.04em;
}

/* --------------------------------------------------------------------------
   13. 团队 / 合作方
   -------------------------------------------------------------------------- */
.team-grid {
  margin-top: var(--s8);
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  gap: var(--s3);
}
.member {
  text-align: center;
}
.avatar {
  width: 100%;
  max-width: 132px;
  margin: 0 auto;
  line-height: 1;
  aspect-ratio: 1;
  border-radius: 50%;
  display: grid;
  place-items: center;
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 700;
  color: var(--sprout);
  background: radial-gradient(
      circle at 34% 28%,
      rgba(124, 224, 122, 0.16),
      rgba(124, 224, 122, 0) 58%
    ),
    linear-gradient(150deg, #332b26, #211c19);
  border: 1px solid rgba(243, 239, 230, 0.1);
  transition: transform 0.4s var(--ease), border-color 0.4s ease;
}
.member:hover .avatar {
  transform: translateY(-4px) rotate(-2deg);
  border-color: rgba(124, 224, 122, 0.4);
}
.member-name {
  margin-top: 12px;
  font-size: 13.5px;
  color: var(--cream);
  font-weight: 600;
}
.member-role {
  margin-top: 2px;
  font-size: 11.5px;
  color: var(--cream-mute);
}

.partners {
  margin-top: var(--s12);
  padding-top: var(--s6);
  border-top: 1px solid rgba(243, 239, 230, 0.08);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--s8);
}
.partners-label {
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--cream-mute);
}
.partner {
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: rgba(243, 239, 230, 0.55);
  transition: color 0.3s ease;
}
.partner:hover {
  color: var(--cream-dim);
}

/* --------------------------------------------------------------------------
   14. 页脚 / 联系
   -------------------------------------------------------------------------- */
.contact {
  position: relative;
  padding: var(--s16) 0 var(--s12);
  border-top: 1px solid rgba(243, 239, 230, 0.1);
  background: linear-gradient(180deg, rgba(38, 32, 28, 0.35), rgba(24, 21, 18, 0.9));
}
.contact-grid {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
  gap: var(--s12);
}

.contact h2 {
  font-size: clamp(1.6rem, 2.8vw, 2.3rem);
  max-width: 9em;
}
.contact-note {
  margin-top: var(--s3);
  color: var(--cream-dim);
  font-size: 14.5px;
  max-width: 20em;
  line-height: 1.85;
}

.contact-list {
  margin-top: var(--s6);
  display: grid;
  gap: 14px;
  font-size: 14px;
  color: var(--cream-dim);
}
.contact-list li {
  display: flex;
  align-items: center;
  gap: 10px;
}
.contact-list svg {
  width: 15px;
  height: 15px;
  stroke: var(--moss);
  fill: none;
  stroke-width: 1.6;
  flex: none;
}
.contact-list a:hover {
  color: var(--sprout);
}

.form {
  display: grid;
  gap: var(--s3);
}
.field {
  display: grid;
  gap: 8px;
}
.field label {
  font-size: 12.5px;
  letter-spacing: 0.06em;
  color: var(--cream-dim);
}
.field input,
.field select,
.field textarea {
  width: 100%;
  font: inherit;
  font-size: 14.5px;
  color: var(--cream);
  background: rgba(24, 21, 18, 0.75);
  border: 1px solid rgba(243, 239, 230, 0.16);
  border-radius: var(--radius);
  padding: 12px 14px;
  transition: border-color 0.25s ease, background 0.25s ease;
  appearance: none;
}
.field textarea {
  resize: vertical;
  min-height: 96px;
}
/* appearance:none 会吃掉原生箭头，自己补一个内联 SVG */
.field select {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'%3E%3Cpath d='M1 1.5 6 6.5 11 1.5' fill='none' stroke='%23C4BBB0' stroke-width='1.5' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 14px center;
  padding-right: 40px;
  cursor: pointer;
}
.field input:hover,
.field select:hover,
.field textarea:hover {
  border-color: rgba(243, 239, 230, 0.28);
}
.field input:focus,
.field select:focus,
.field textarea:focus {
  border-color: var(--sprout);
  background: rgba(24, 21, 18, 0.95);
  outline: none;
  box-shadow: 0 0 0 3px rgba(124, 224, 122, 0.14);
}
.field ::placeholder {
  color: #7d736b;
}
.field-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: var(--s3);
}

.form-foot {
  display: flex;
  align-items: center;
  gap: var(--s3);
  flex-wrap: wrap;
}
.form-hint {
  font-size: 12px;
  color: var(--cream-mute);
  line-height: 1.6;
}
.form-status {
  font-size: 13px;
  color: var(--sprout);
  min-height: 1.4em;
}

/* 蜜罐：不能用 display:none —— 部分爬虫会跳过 display 为 none 的字段。
   用绝对定位挪出视口 + clip 双保险，读屏软件也读不到。 */
.hp {
  position: absolute;
  left: -9999px;
  width: 1px;
  height: 1px;
  overflow: hidden;
}

/* 表单旁的直连方式：表单挂掉、或备案期不收集时，靠它兜住线索 */
.contact-direct {
  margin-top: var(--s3);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--s2);
}
.contact-direct-label {
  width: 100%;
  font-size: 12.5px;
  color: var(--cream-mute);
  letter-spacing: 0.04em;
}
.contact-direct .btn {
  padding: 11px 18px;
  font-size: 13.5px;
}
/* 备案期隐藏表单后，直连按钮升为主要入口，给一点视觉权重 */
.contact-direct.is-primary {
  margin-top: 0;
}
.contact-direct.is-primary .btn--ghost {
  border-color: rgba(232, 196, 106, 0.45);
  color: var(--wheat);
}

/* 页脚底栏 */
.footer-bottom {
  margin-top: var(--s12);
  padding-top: var(--s3);
  border-top: 1px solid rgba(243, 239, 230, 0.08);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--s4);
  font-size: 12.5px;
  color: var(--cream-mute);
}
.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: var(--s3);
}
.footer-links a:hover {
  color: var(--cream-dim);
}

.qr {
  display: flex;
  align-items: center;
  gap: 14px;
}
.qr svg {
  width: 76px;
  height: 76px;
  border-radius: 4px;
  flex: none;
}
.qr span {
  font-size: 12px;
  line-height: 1.6;
  color: var(--cream-mute);
  max-width: 12ch;
}

/* --------------------------------------------------------------------------
   15. 二级页（tech / case）页头
   -------------------------------------------------------------------------- */
.page-head {
  position: relative;
  padding: var(--s16) 0 var(--s12);
  border-bottom: 1px solid rgba(243, 239, 230, 0.08);
  overflow: hidden;
  isolation: isolate;
}
.page-head::before {
  content: "";
  position: absolute;
  inset: -30% -10%;
  z-index: -1;
  background: radial-gradient(
    38% 48% at 22% 0%,
    rgba(232, 196, 106, 0.16),
    rgba(232, 196, 106, 0) 60%
  );
  filter: blur(16px);
  mix-blend-mode: screen;
}
.page-head h1 {
  font-size: clamp(2.1rem, 5vw, 3.6rem);
  max-width: 11em;
  margin-top: var(--s3);
}
.page-head p {
  margin-top: var(--s3);
  max-width: 36em;
  color: var(--cream-dim);
  font-size: 16px;
  line-height: 1.85;
}

.breadcrumb {
  display: flex;
  gap: 8px;
  font-size: 12.5px;
  color: var(--cream-mute);
  margin-bottom: var(--s4);
}
.breadcrumb a:hover {
  color: var(--sprout);
}

/* 技术详情条目 */
.spec {
  display: grid;
  grid-template-columns: 200px minmax(0, 1fr);
  gap: var(--s12);
  padding: var(--s12) 0;
  border-top: 1px solid rgba(243, 239, 230, 0.08);
}
.spec:first-of-type {
  border-top: 0;
}
.spec-head {
  position: sticky;
  top: 96px;
  align-self: start;
}
.spec-no {
  font-family: var(--font-display);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--wheat);
}
.spec-head h2 {
  margin-top: 12px;
  font-size: clamp(1.3rem, 2vw, 1.65rem);
}
.spec-head .tech-ico {
  width: 30px;
  height: 30px;
  margin-bottom: var(--s3);
}
.spec-body p {
  color: var(--cream-dim);
  font-size: 15px;
  line-height: 1.9;
  max-width: 34em;
}
.spec-body p + p {
  margin-top: var(--s2);
}
.spec-kpis {
  margin-top: var(--s6);
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  background: rgba(243, 239, 230, 0.09);
  border: 1px solid rgba(243, 239, 230, 0.09);
  border-radius: var(--radius);
  overflow: hidden;
}
.spec-kpi {
  background: var(--deep);
  padding: var(--s3);
}
.spec-kpi b {
  display: block;
  font-family: var(--font-display);
  font-size: 21px;
  font-weight: 700;
  color: var(--sprout);
  font-variant-numeric: tabular-nums;
}
.spec-kpi span {
  font-size: 12px;
  color: var(--cream-mute);
}
.spec-diagram {
  margin-top: var(--s6);
  border: 1px solid rgba(243, 239, 230, 0.1);
  border-radius: var(--radius-lg);
  background: linear-gradient(160deg, #262019, #191512);
  padding: var(--s4);
}
.spec-diagram svg {
  width: 100%;
  height: auto;
}
.spec-diagram figcaption {
  margin-top: var(--s2);
  font-size: 12px;
  color: var(--cream-mute);
}

/* 小屏示意图的替代方案（见 tech.html 里 .diagram-mobile）：
   720×240 的 viewBox 在 375 宽的容器里缩放比约 0.39，
   图内 11px 标注实际只有 4.3px —— 不是"偏小"，是看不见。
   所以 600px 以下直接换成语义化的参数列表，而不是把图缩小。 */
.diagram-mobile {
  display: none;
  margin: var(--s2) 0 0;
  padding: 0;
  list-style: none;
  font-size: 13.5px;
  line-height: 1.7;
}
.diagram-mobile li {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 4px 12px;
  padding: 9px 0;
  border-top: 1px solid rgba(243, 239, 230, 0.08);
  color: var(--cream-dim);
}
.diagram-mobile li:first-child {
  border-top: 0;
}
.diagram-mobile b {
  font-family: var(--font-display);
  color: var(--wheat);
  font-weight: 600;
  font-variant-numeric: tabular-nums;
}

@media (max-width: 600px) {
  .spec-diagram svg {
    display: none;
  }
  .diagram-mobile {
    display: block;
  }
  /* 只有一个 SVG、没有替代列表的图，保留可横向拖动作为兜底 */
  .spec-diagram:not(:has(.diagram-mobile)) {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
  }
  .spec-diagram:not(:has(.diagram-mobile)) svg {
    display: block;
    width: 720px;
    max-width: none;
  }
}

/* 案例页大数字 */
.case-hero-metrics {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1px;
  margin-top: var(--s12);
  background: rgba(243, 239, 230, 0.09);
  border: 1px solid rgba(243, 239, 230, 0.09);
  border-radius: var(--radius-lg);
  overflow: hidden;
}
.case-hero-metrics div {
  background: var(--deep);
  padding: var(--s4);
}
.case-hero-metrics b {
  display: block;
  font-family: var(--font-display);
  font-size: clamp(24px, 3vw, 32px);
  font-weight: 700;
  color: var(--cream);
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.02em;
}
.case-hero-metrics span {
  font-size: 12.5px;
  color: var(--cream-mute);
}

/* 通用页尾行动条 */
.cta-band {
  padding: var(--s12) 0;
  border-top: 1px solid rgba(243, 239, 230, 0.08);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--s4);
}
.cta-band h2 {
  font-size: clamp(1.3rem, 2.4vw, 1.8rem);
  max-width: 15em;
}

/* --------------------------------------------------------------------------
   16. 省电模式：关掉全部自动动画，保留完整布局与可读性
   -------------------------------------------------------------------------- */
.eco .hero::before,
.eco .hero::after {
  animation: none;
  opacity: 0.55;
}
.eco .vine-line {
  animation: none;
  stroke-dashoffset: 0;
}
.eco .bud {
  animation: none;
  opacity: 1;
  transform: none;
}
.eco .bud-blade {
  animation: none;
}
.eco .cursor-glow {
  display: none;
}
.eco .scroll-hint::after {
  animation: none;
  opacity: 0.5;
}
.eco .grain {
  opacity: 0.03;
}
.eco .nav {
  backdrop-filter: none;
  -webkit-backdrop-filter: none;
  background: rgba(30, 26, 23, 0.97);
}

/* --------------------------------------------------------------------------
   17. 无障碍：尊重系统减少动效
   -------------------------------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
  .vine-line {
    animation: none;
    stroke-dashoffset: 0;
  }
  .bud {
    animation: none;
    opacity: 1;
    transform: none;
  }
  .bud-blade {
    animation: none;
  }
  .js .reveal {
    opacity: 1;
    transform: none;
  }
  .cursor-glow {
    display: none;
  }
  .hero::before {
    animation: none;
  }
}

/* --------------------------------------------------------------------------
   18. 响应式：1440 / 1024 / 768 / 375
   -------------------------------------------------------------------------- */
@media (max-width: 1280px) {
  .stem,
  .node {
    display: none; /* 视口不够宽时茎干会压到内容，直接不做 */
  }
}

@media (max-width: 1024px) {
  :root {
    --s16: 96px;
    --s12: 72px;
  }
  .tech-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .tech-card {
    min-height: 200px;
  }
  .rings {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .timeline {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: var(--s4) var(--s3);
  }
  .timeline::before {
    display: none;
  }
  .tl-item {
    padding-top: var(--s6);
  }
  .tl-dot {
    top: 6px;
  }
  .case-row {
    grid-template-columns: minmax(0, 1fr);
    gap: var(--s6);
  }
  .case-row:nth-of-type(even) .case-figure {
    order: 0;
  }
  .contact-grid {
    grid-template-columns: minmax(0, 1fr);
    gap: var(--s8);
  }
  .team-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: var(--s4) var(--s3);
  }
  .spec {
    grid-template-columns: minmax(0, 1fr);
    gap: var(--s4);
  }
  .spec-head {
    position: static;
  }
  .case-hero-metrics {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 768px) {
  :root {
    --s16: 72px;
    --s12: 56px;
    --s8: 40px;
  }
  body {
    font-size: 15px;
  }
  /* 375 下 1.75rem 的标题会把 13 字标题挤出一个孤字，收到 1.5rem 正好一行 */
  .section-title {
    font-size: 1.5rem;
  }
  .wrap,
  .nav-inner,
  .hero-inner {
    padding-left: var(--s3);
    padding-right: var(--s3);
  }
  .nav-inner {
    height: 56px;
    gap: var(--s2);
  }
  .brand-en {
    display: none;
  }
  .nav-links {
    gap: var(--s2);
    font-size: 13.5px;
  }
  .eco {
    padding: 6px 9px;
  }
  .eco .eco-label {
    display: none;
  }
  .hero {
    min-height: clamp(520px, 86vh, 720px);
    padding: var(--s12) 0 var(--s8);
  }
  .hero-lede {
    font-size: 14.5px;
  }
  .hero-stats {
    gap: var(--s4);
    margin-top: var(--s8);
  }
  .hero-stat b {
    font-size: 21px;
  }
  .scroll-hint {
    display: none;
  }
  /* 375 下 viewBox 是 16:10、容器是 9:19，slice 只能截取中段，
     28px 的叶子缩到 7px 成了绿点，所以小屏只留茎、不留叶 */
  .vine {
    opacity: 0.32;
  }
  .bud {
    display: none;
  }
  /* 移动端降低视觉开销：光斑缩小、模糊减弱 */
  .hero::before {
    filter: blur(10px);
    inset: -10% -10%;
    /* blur + mix-blend-mode 已经是全站最贵的一处，
       小屏再常驻一层合成层，低端安卓会掉帧。这里交还控制权 */
    will-change: auto;
  }
  .cursor-glow {
    display: none;
  }
  .tech-grid {
    grid-template-columns: minmax(0, 1fr);
  }
  .tech-card {
    min-height: 0;
    padding: var(--s4);
  }
  /* 移动端取消倾斜，避免误触抖动 */
  .tech-card:hover {
    transform: none;
  }
  .rings {
    gap: var(--s2);
  }
  .ring-card {
    padding: var(--s2);
  }
  .timeline {
    grid-template-columns: minmax(0, 1fr);
  }
  .team-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .spec-kpis {
    grid-template-columns: 1fr;
  }
  .field-row {
    grid-template-columns: minmax(0, 1fr);
  }
  .partners {
    gap: var(--s4);
  }
  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
  }
  .cta-band {
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (max-width: 520px) {
  /* 小屏导航：品牌 + 3 个链接 + 省电图标要在 375 里塞下，
     任何一项留足尺寸都会把「省电」推出屏幕，所以这里全部收紧 */
  .nav-inner {
    gap: 8px;
    padding-left: 20px;
    padding-right: 20px;
  }
  .brand {
    font-size: 15px;
    gap: 6px;
  }
  .brand svg {
    width: 19px;
    height: 19px;
  }
  .nav-links {
    gap: 10px;
    font-size: 13px;
    flex: none;
  }
  .nav-links a:last-child {
    display: none;
  }
  .eco {
    padding: 5px 8px;
    flex: none;
  }

  .hero h1 {
    /* 主标语现在是 7 个字，375 下 2.3rem 正好一行（258px < 327px 内容宽）。
       原来限 5em 是为了老文案的 9 字标题，现在会把「土里」挤成孤字，放开 */
    max-width: 8em;
    font-size: 2.3rem;
  }
  .btn {
    padding: 13px 20px;
    font-size: 14px;
  }
  .cta-row {
    gap: 10px;
  }

  /* 统计条：三个数字挤在一行比折成三行好看，缩字号换空间 */
  .hero-stats {
    gap: var(--s2);
    margin-top: var(--s8);
  }
  .hero-stat b {
    font-size: 19px;
  }
  .hero-stat span {
    font-size: 11.5px;
  }

  /* 年轮：单列会让四个圆各占一整屏高，2×2 更紧凑 */
  .rings {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: var(--s2);
  }
  .ring-card {
    padding: 12px;
  }
  .ring-meta b {
    font-size: 22px;
  }
  .ring-meta span {
    margin-top: 6px;
    font-size: 11.5px;
  }
  .case-metrics {
    gap: var(--s4);
  }
}

/* 打印：去掉所有装饰，只留文字 */
@media print {
  .grain,
  .cursor-glow,
  .vine,
  .stem,
  .node,
  .nav,
  .scroll-hint,
  .hero::before {
    display: none !important;
  }
  body {
    background: #fff;
    color: #000;
  }
}