/* ==========================================================================
   国医控股 Guoyi Holding — Design System
   纯黑科技风 / Neuralyn + Synapse 血统
   零外部依赖：不加载任何 Web Font，全部使用系统字体栈（国内访问快、不耗流量）
   ========================================================================== */

/* ---------- 1. Design Tokens ---------- */
:root {
  /* 色板：纯黑为底，白为主文字，生命绿为唯一强调色 */
  --bg:            #000000;
  --bg-elev:       #070707;
  --card:          #0b0b0b;
  --card-hover:    #111111;
  --border:        #242424;
  --border-strong: #333333;

  --fg:            #ffffff;
  --muted:         #a6a6a6;
  --muted-2:       #6e6e6e;

  /* 强调色：由原站 brand 生命绿 #00cc99 提亮，适配纯黑背景 */
  --accent:        #00e0a4;
  --accent-dim:    rgba(0, 224, 164, 0.14);
  --accent-glow:   rgba(0, 224, 164, 0.35);
  /* 次强调：原站 AI 紫 */
  --accent-2:      #8b5cf6;

  /* 排版 */
  --font-sans: "PingFang SC", "HarmonyOS Sans SC", "Microsoft YaHei",
               "Noto Sans SC", -apple-system, BlinkMacSystemFont,
               "Segoe UI", Roboto, "Helvetica Neue", sans-serif;
  /* 中文强调用宋体：黑体大标题 + 宋体强调，是中文排版里最接近
     Neuralyn「Instrument Serif 意大利体」的高级感手法，且贴合「国医」气质 */
  --font-serif: "Songti SC", "STSong", "SimSun", "Source Han Serif SC",
                Georgia, "Times New Roman", serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo,
               Consolas, "Liberation Mono", monospace;

  /* 间距 */
  --sp-1: 4px;  --sp-2: 8px;  --sp-3: 16px; --sp-4: 24px;
  --sp-5: 32px; --sp-6: 48px; --sp-7: 64px; --sp-8: 96px; --sp-9: 128px;

  /* 圆角 */
  --r-sm: 8px; --r-md: 12px; --r-lg: 16px; --r-xl: 24px; --r-2xl: 32px; --r-full: 999px;

  /* 动效（Neuralyn 同款缓动曲线，高级感的关键） */
  --ease: cubic-bezier(0.16, 1, 0.3, 1);
  --dur: 700ms;
  --dur-fast: 320ms;

  /* 版心 */
  --container: 1240px;
  --nav-h: 76px;
}

/* ---------- 2. Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
img, svg, canvas { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button, input, select, textarea { font: inherit; color: inherit; }
h1, h2, h3, h4, p, ul, ol, figure { margin: 0; }
ul, ol { padding: 0; list-style: none; }
::selection { background: var(--accent); color: #000; }

/* 细滚动条 */
::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: #0a0a0a; }
::-webkit-scrollbar-thumb { background: #2a2a2a; border-radius: 999px; }
::-webkit-scrollbar-thumb:hover { background: #3a3a3a; }

/* ---------- 3. Layout ---------- */
.container { width: 100%; max-width: var(--container); margin: 0 auto; padding: 0 24px; }
.section { padding: clamp(72px, 10vw, 148px) 0; position: relative; }
.section--tight { padding: clamp(56px, 7vw, 96px) 0; }
.divider { height: 1px; background: var(--border); border: 0; margin: 0; }

/* ---------- 4. Typography ---------- */
h1, .h1 { font-size: clamp(2.1rem, 6.2vw, 4.6rem); line-height: 1.08; letter-spacing: -0.02em; font-weight: 500; }
h2, .h2 { font-size: clamp(1.8rem, 4.4vw, 3.2rem); line-height: 1.14; letter-spacing: -0.02em; font-weight: 500; }
h3, .h3 { font-size: clamp(1.15rem, 2.2vw, 1.5rem); line-height: 1.3; font-weight: 600; letter-spacing: -0.01em; }
.lead { font-size: clamp(1rem, 1.5vw, 1.15rem); color: var(--muted); line-height: 1.85; }
.muted { color: var(--muted); }
.muted-2 { color: var(--muted-2); }

/* 宋体强调词（对应参考稿里的 serif italic accent） */
.accent-serif {
  font-family: var(--font-serif);
  font-weight: 400;
  font-style: normal;
  letter-spacing: 0.01em;
}
/* 生命绿强调 */
.accent { color: var(--accent); }

.eyebrow {
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.3em;
  text-transform: uppercase;
  color: var(--muted-2);
  margin-bottom: var(--sp-4);
  display: flex;
  align-items: center;
  gap: 12px;
}
.eyebrow::before {
  content: "";
  width: 24px; height: 1px;
  background: var(--accent);
  display: inline-block;
}
.eyebrow--plain::before { display: none; }

/* ---------- 5. Liquid Glass（取自 Neuralyn 参考稿的 CSS 实现） ---------- */
.liquid-glass {
  background: rgba(255, 255, 255, 0.01);
  background-blend-mode: luminosity;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: none;
  box-shadow: inset 0 1px 1px rgba(255, 255, 255, 0.08);
  position: relative;
  overflow: hidden;
}
.liquid-glass::before {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  padding: 1.4px;
  background: linear-gradient(180deg,
    rgba(255, 255, 255, 0.42) 0%, rgba(255, 255, 255, 0.14) 20%,
    rgba(255, 255, 255, 0) 40%, rgba(255, 255, 255, 0) 60%,
    rgba(255, 255, 255, 0.14) 80%, rgba(255, 255, 255, 0.42) 100%);
  -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  pointer-events: none;
}

/* ---------- 6. Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border: 0;
  cursor: pointer;
  border-radius: var(--r-full);
  padding: 13px 28px;
  font-size: 15px;
  font-weight: 500;
  line-height: 1;
  transition: transform var(--dur-fast) var(--ease),
              background-color var(--dur-fast) var(--ease),
              border-color var(--dur-fast) var(--ease),
              opacity var(--dur-fast) var(--ease);
  white-space: nowrap;
}
.btn:active { transform: scale(0.97); }
.btn--primary { background: var(--fg); color: #000; }
.btn--primary:hover { transform: scale(1.03); }
.btn--ghost {
  background: transparent;
  color: var(--fg);
  border: 1px solid var(--border-strong);
}
.btn--ghost:hover { border-color: var(--fg); }
.btn--accent { background: var(--accent); color: #001b13; font-weight: 600; }
.btn--accent:hover { transform: scale(1.03); box-shadow: 0 0 32px var(--accent-glow); }
.btn__icon {
  width: 26px; height: 26px;
  border-radius: 50%;
  display: grid; place-items: center;
  background: rgba(255, 255, 255, 0.12);
  flex: 0 0 auto;
}
.link-underline {
  border-bottom: 1px solid var(--border-strong);
  padding-bottom: 2px;
  transition: border-color var(--dur-fast) var(--ease);
}
.link-underline:hover { border-color: var(--accent); }

/* ---------- 7. Navbar ---------- */
.nav {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 100;
  height: var(--nav-h);
  display: flex;
  align-items: center;
  transition: background-color var(--dur-fast) var(--ease),
              border-color var(--dur-fast) var(--ease),
              backdrop-filter var(--dur-fast) var(--ease);
  border-bottom: 1px solid transparent;
}
.nav.is-scrolled {
  background: rgba(0, 0, 0, 0.72);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom-color: var(--border);
}
.nav__inner { display: flex; align-items: center; justify-content: space-between; gap: 24px; width: 100%; }
.nav__logo { display: flex; align-items: baseline; gap: 10px; font-weight: 700; letter-spacing: -0.01em; }
.nav__logo-cn { font-size: 19px; }
.nav__logo-en {
  font-size: 11px; font-weight: 500; letter-spacing: 0.22em;
  text-transform: uppercase; color: var(--muted-2);
}
.nav__links { display: flex; align-items: center; gap: 34px; }
.nav__link {
  font-size: 14px; font-weight: 500; color: var(--muted);
  transition: color var(--dur-fast) var(--ease);
  position: relative;
}
.nav__link:hover, .nav__link.is-active { color: var(--fg); }
.nav__link.is-active::after {
  content: ""; position: absolute; left: 0; right: 0; bottom: -7px;
  height: 1px; background: var(--accent);
}
.nav__right { display: flex; align-items: center; gap: 16px; }
.nav__lang {
  display: flex; align-items: center; gap: 6px;
  font-size: 13px; color: var(--muted); background: none; border: 0;
  cursor: pointer; padding: 8px 10px; border-radius: var(--r-full);
}
.nav__lang:hover { color: var(--fg); background: rgba(255, 255, 255, 0.05); }
.nav__lang-menu {
  position: absolute; top: calc(var(--nav-h) - 8px); right: 24px;
  min-width: 150px; padding: 6px;
  background: #0c0c0c; border: 1px solid var(--border);
  border-radius: var(--r-md); display: none; z-index: 120;
}
.nav__lang-menu.is-open { display: block; }
.nav__lang-menu button {
  display: block; width: 100%; text-align: left;
  padding: 9px 12px; border: 0; background: none; cursor: pointer;
  border-radius: var(--r-sm); font-size: 14px; color: var(--muted);
}
.nav__lang-menu button:hover { background: rgba(255, 255, 255, 0.06); color: var(--fg); }
.nav__lang-menu button.is-active { color: var(--accent); }
.nav__toggle {
  display: none; width: 42px; height: 42px; border-radius: 50%;
  border: 1px solid var(--border-strong); background: none; cursor: pointer;
  place-items: center;
}
.nav__toggle span {
  display: block; width: 16px; height: 1.5px; background: var(--fg); position: relative;
}
.nav__toggle span::before, .nav__toggle span::after {
  content: ""; position: absolute; left: 0; width: 16px; height: 1.5px; background: var(--fg);
}
.nav__toggle span::before { top: -5px; }
.nav__toggle span::after { top: 5px; }
.nav__mobile {
  position: fixed; inset: var(--nav-h) 0 auto 0; z-index: 99;
  background: rgba(0, 0, 0, 0.96);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
  padding: 16px 24px 28px;
  display: none;
}
.nav__mobile.is-open { display: block; }
.nav__mobile a {
  display: block; padding: 14px 0; font-size: 17px;
  border-bottom: 1px solid #141414; color: var(--muted);
}
.nav__mobile a.is-active, .nav__mobile a:hover { color: var(--fg); }

/* ---------- 8. Hero ---------- */
.hero {
  position: relative;
  min-height: 100svh;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  overflow: hidden;
  padding-top: var(--nav-h);
}
.hero__canvas {
  position: absolute; inset: 0; z-index: 0;
  width: 100%; height: 100%;
}
/* 底部渐隐，让内容压住 canvas */
.hero__fade {
  position: absolute; left: 0; right: 0; bottom: 0; height: 42vh; z-index: 1;
  background: linear-gradient(to top, var(--bg) 8%, rgba(0,0,0,0.72) 45%, transparent 100%);
  pointer-events: none;
}
.hero__radial {
  position: absolute; z-index: 0; pointer-events: none;
  width: 1100px; height: 1100px; left: 50%; top: 42%;
  transform: translate(-50%, -50%);
  background: radial-gradient(circle,
      rgba(0, 224, 164, 0.10) 0%,
      rgba(139, 92, 246, 0.05) 38%,
      transparent 68%);
}
.hero__inner {
  position: relative; z-index: 2;
  padding-bottom: clamp(40px, 8vh, 88px);
  display: flex; flex-direction: column; gap: clamp(28px, 5vh, 52px);
}
.hero__tag {
  align-self: flex-start;
  display: inline-flex; align-items: center; gap: 10px;
  padding: 7px 16px 7px 8px; border-radius: var(--r-full);
  font-size: 13px; color: var(--muted);
}
.hero__tag b {
  background: var(--fg); color: #000; font-weight: 600;
  font-size: 11px; letter-spacing: 0.04em;
  padding: 3px 8px; border-radius: 6px;
}
.hero__title { max-width: 15ch; }
.hero__title .line { display: block; }
.hero__sub {
  max-width: 46ch; color: var(--muted);
  font-size: clamp(0.98rem, 1.4vw, 1.1rem); line-height: 1.85;
}
.hero__actions { display: flex; flex-wrap: wrap; align-items: center; gap: 18px; }
.hero__bottom {
  display: flex; flex-wrap: wrap; align-items: flex-end;
  justify-content: space-between; gap: 24px;
  border-top: 1px solid var(--border);
  padding-top: 22px;
}
.hero__tags { display: flex; flex-wrap: wrap; gap: 10px; }
.chip {
  font-size: 12px; color: var(--muted);
  border: 1px solid var(--border); border-radius: var(--r-full);
  padding: 6px 14px;
  transition: border-color var(--dur-fast) var(--ease), color var(--dur-fast) var(--ease);
}
.chip:hover { border-color: var(--border-strong); color: var(--fg); }
.scroll-hint {
  display: flex; align-items: center; gap: 10px;
  font-size: 12px; letter-spacing: 0.2em; text-transform: uppercase; color: var(--muted-2);
}
.scroll-hint i {
  width: 1px; height: 34px; background: linear-gradient(var(--accent), transparent);
  animation: scrollPulse 2.2s var(--ease) infinite;
}
@keyframes scrollPulse {
  0% { transform: scaleY(0.2); opacity: 0.3; transform-origin: top; }
  50% { transform: scaleY(1); opacity: 1; transform-origin: top; }
  100% { transform: scaleY(0.2); opacity: 0.3; transform-origin: top; }
}

/* ---------- 9. Stats ---------- */
.stats {
  display: grid; grid-template-columns: repeat(4, 1fr);
  border: 1px solid var(--border); border-radius: var(--r-xl);
  overflow: hidden; background: var(--card);
}
.stat { padding: clamp(22px, 3vw, 34px); border-right: 1px solid var(--border); }
.stat:last-child { border-right: 0; }
.stat__num {
  font-family: var(--font-sans);
  font-size: clamp(2rem, 4.4vw, 3.1rem);
  font-weight: 600; line-height: 1; letter-spacing: -0.03em;
  display: flex; align-items: baseline; gap: 2px;
}
.stat__num em { font-style: normal; color: var(--accent); font-size: 0.62em; font-weight: 600; }
.stat__label { margin-top: 12px; font-size: 14px; color: var(--muted); }

/* ---------- 10. Cards / Grid ---------- */
.grid { display: grid; gap: 16px; }
.grid--2 { grid-template-columns: repeat(2, 1fr); }
.grid--3 { grid-template-columns: repeat(3, 1fr); }
.grid--4 { grid-template-columns: repeat(4, 1fr); }

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--r-xl);
  padding: clamp(22px, 2.6vw, 32px);
  transition: background-color var(--dur-fast) var(--ease),
              border-color var(--dur-fast) var(--ease),
              transform var(--dur-fast) var(--ease);
  position: relative; overflow: hidden;
}
.card:hover { background: var(--card-hover); border-color: var(--border-strong); }
.card__icon {
  width: 44px; height: 44px; border-radius: var(--r-md);
  display: grid; place-items: center; font-size: 21px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border);
  margin-bottom: 20px;
}
.card__title { font-size: 17px; font-weight: 600; margin-bottom: 10px; }
.card__desc { font-size: 14.5px; color: var(--muted); line-height: 1.75; }
/* 悬停时右上角泛出的生命绿光晕 */
.card--glow::after {
  content: ""; position: absolute; top: -60px; right: -60px;
  width: 160px; height: 160px; border-radius: 50%;
  background: var(--accent-glow); filter: blur(60px);
  opacity: 0; transition: opacity var(--dur) var(--ease);
  pointer-events: none;
}
.card--glow:hover::after { opacity: 0.5; }

/* 数字序号卡（对应参考稿的 01/02/03） */
.step { position: relative; padding-top: 26px; border-top: 1px solid var(--border); }
.step__no {
  font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.14em;
  color: var(--accent); margin-bottom: 14px; display: block;
}
.step__title { font-size: 18px; font-weight: 600; margin-bottom: 10px; }
.step__desc { font-size: 14.5px; color: var(--muted); line-height: 1.8; }

/* ---------- 11. Tabs（12 个技术平台的分类筛选） ---------- */
.tabs { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 34px; }
.tab {
  border: 1px solid var(--border); background: transparent; color: var(--muted);
  border-radius: var(--r-full); padding: 9px 20px; font-size: 14px; cursor: pointer;
  transition: all var(--dur-fast) var(--ease);
}
.tab:hover { color: var(--fg); border-color: var(--border-strong); }
.tab.is-active { background: var(--fg); color: #000; border-color: var(--fg); font-weight: 600; }
.platform { display: flex; flex-direction: column; }
.platform[hidden] { display: none; }
.platform__tags { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 16px; }
.tag {
  font-size: 11.5px; color: var(--muted);
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border);
  border-radius: 6px; padding: 4px 9px;
}

/* ---------- 12. Marquee（灰度 logo 跑马灯） ---------- */
.marquee {
  overflow: hidden; position: relative;
  mask-image: linear-gradient(90deg, transparent, #000 12%, #000 88%, transparent);
  -webkit-mask-image: linear-gradient(90deg, transparent, #000 12%, #000 88%, transparent);
}
.marquee__track { display: flex; gap: 64px; width: max-content; animation: marquee 42s linear infinite; }
.marquee:hover .marquee__track { animation-play-state: paused; }
.marquee__item {
  font-size: 15px; font-weight: 600; letter-spacing: 0.02em;
  color: var(--fg); opacity: 0.4; white-space: nowrap;
  transition: opacity var(--dur-fast) var(--ease);
}
.marquee__item:hover { opacity: 1; }
@keyframes marquee { from { transform: translateX(0); } to { transform: translateX(-50%); } }

/* ---------- 13. 滚动逐词点亮（Neuralyn 同款叙事手法） ---------- */
.word-reveal { display: flex; flex-wrap: wrap; gap: 0; }
.word-reveal span {
  margin-right: 0.3em;
  color: #3a3a3a;
  transition: color 520ms var(--ease), opacity 520ms var(--ease);
  opacity: 0.35;
}
.word-reveal span.is-lit { color: var(--fg); opacity: 1; }
.quote {
  font-size: clamp(1.35rem, 3.4vw, 2.5rem);
  line-height: 1.45; font-weight: 500; letter-spacing: -0.01em;
  max-width: 34ch;
}
.quote__mark {
  font-family: var(--font-serif); font-size: 3.4rem; line-height: 1;
  color: var(--accent); margin-bottom: 14px; display: block;
}

/* ---------- 14. 富文本块 / 双栏 ---------- */
.split { display: grid; grid-template-columns: 1.05fr 0.95fr; gap: clamp(32px, 6vw, 80px); align-items: center; }
.split--top { align-items: start; }
.prose p { color: var(--muted); line-height: 1.95; margin-bottom: 18px; }
.prose p:last-child { margin-bottom: 0; }
.prose strong { color: var(--fg); font-weight: 600; }
.feature-list { display: grid; gap: 18px; }
.feature-list li { display: flex; gap: 14px; align-items: flex-start; }
.feature-list .dot {
  width: 6px; height: 6px; border-radius: 50%; background: var(--accent);
  margin-top: 11px; flex: 0 0 auto;
}
.feature-list .feature-list__text { font-size: 15px; color: var(--muted); line-height: 1.8; }

/* 视觉方块（替代参考稿里的视频卡，零流量消耗） */
.visual {
  position: relative; border-radius: var(--r-2xl);
  border: 1px solid var(--border); background: #050505;
  aspect-ratio: 4 / 3; overflow: hidden;
}
.visual canvas, .visual .visual__mesh { position: absolute; inset: 0; width: 100%; height: 100%; }
.visual__label {
  position: absolute; left: 22px; bottom: 20px; z-index: 2;
  font-size: 13px; color: var(--muted);
}
.visual__badge {
  position: absolute; top: 20px; left: 20px; z-index: 2;
  font-size: 12px; color: var(--fg); padding: 6px 13px; border-radius: var(--r-full);
}
/* 纯 CSS 网格底纹，替代视频/图片背景 */
.grid-bg {
  background-image:
    linear-gradient(rgba(255,255,255,0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.045) 1px, transparent 1px);
  background-size: 46px 46px;
}

/* ---------- 15. 表格（能力矩阵） ---------- */
.matrix { border: 1px solid var(--border); border-radius: var(--r-xl); overflow: hidden; }
.matrix__row {
  display: grid; grid-template-columns: 260px 1fr; gap: 24px;
  padding: 24px clamp(20px, 3vw, 32px);
  border-bottom: 1px solid var(--border);
  transition: background-color var(--dur-fast) var(--ease);
}
.matrix__row:last-child { border-bottom: 0; }
.matrix__row:hover { background: var(--card); }
.matrix__key { font-size: 15px; font-weight: 600; display: flex; align-items: center; gap: 10px; }
.matrix__key .no { font-family: var(--font-mono); font-size: 12px; color: var(--accent); }
.matrix__val { font-size: 14.5px; color: var(--muted); line-height: 1.8; }

/* ---------- 16. 表单 ---------- */
.form { display: grid; gap: 18px; }
.form__row { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.field { display: flex; flex-direction: column; gap: 8px; }
.field label { font-size: 13px; color: var(--muted); }
.field label .req { color: var(--accent); }
.field input, .field select, .field textarea {
  background: #0a0a0a; border: 1px solid var(--border);
  border-radius: var(--r-md); padding: 13px 15px; font-size: 15px;
  transition: border-color var(--dur-fast) var(--ease), background-color var(--dur-fast) var(--ease);
  width: 100%;
}
.field input::placeholder, .field textarea::placeholder { color: #555; }
.field input:focus, .field select:focus, .field textarea:focus {
  outline: none; border-color: var(--accent); background: #0d0d0d;
}
.field textarea { resize: vertical; min-height: 132px; }
.field select { appearance: none; cursor: pointer; }
.form__note { font-size: 13px; color: var(--muted-2); }
.form__status { font-size: 14px; min-height: 22px; }
.form__status.is-ok { color: var(--accent); }
.form__status.is-err { color: #ff6b6b; }

/* ---------- 17. 联系信息 ---------- */
.contact-item { display: flex; gap: 16px; align-items: flex-start; }
.contact-item__icon {
  width: 42px; height: 42px; border-radius: var(--r-md); flex: 0 0 auto;
  display: grid; place-items: center; font-size: 18px;
  background: rgba(255,255,255,0.05); border: 1px solid var(--border);
}
.contact-item__label { font-size: 13px; color: var(--muted-2); margin-bottom: 4px; }
.contact-item__value { font-size: 15px; line-height: 1.65; word-break: break-word; }

/* ---------- 18. CTA 区 ---------- */
.cta {
  border: 1px solid var(--border); border-radius: var(--r-2xl);
  padding: clamp(36px, 6vw, 76px);
  background:
    radial-gradient(900px 380px at 78% 20%, rgba(0,224,164,0.10), transparent 62%),
    radial-gradient(700px 340px at 12% 88%, rgba(139,92,246,0.08), transparent 60%),
    var(--card);
  position: relative; overflow: hidden;
}

/* ---------- 19. Footer ---------- */
.footer { border-top: 1px solid var(--border); padding: 64px 0 32px; margin-top: 0; }
.footer__grid { display: grid; grid-template-columns: 1.5fr 1fr 1fr 1.3fr; gap: 40px; }
.footer__brand { font-size: 19px; font-weight: 700; margin-bottom: 6px; }
.footer__en {
  font-size: 11px; letter-spacing: 0.22em; text-transform: uppercase;
  color: var(--muted-2); margin-bottom: 18px;
}
.footer__desc { font-size: 14px; color: var(--muted); line-height: 1.85; max-width: 34ch; }
.footer__title { font-size: 14px; font-weight: 600; margin-bottom: 18px; }
.footer__list li { margin-bottom: 11px; }
.footer__list a { font-size: 14px; color: var(--muted); transition: color var(--dur-fast) var(--ease); }
.footer__list a:hover { color: var(--accent); }
.footer__bottom {
  margin-top: 52px; padding-top: 24px; border-top: 1px solid var(--border);
  display: flex; flex-wrap: wrap; gap: 16px; justify-content: space-between;
  font-size: 13px; color: var(--muted-2);
}
.footer__legal { display: flex; gap: 18px; flex-wrap: wrap; }
.footer__legal a:hover { color: var(--muted); }

/* 悬浮客服按钮 */
.fab {
  position: fixed; right: 24px; bottom: 24px; z-index: 90;
  width: 54px; height: 54px; border-radius: 50%;
  display: grid; place-items: center; font-size: 22px;
  background: var(--fg); color: #000; border: 0; cursor: pointer;
  box-shadow: 0 10px 34px rgba(0,0,0,0.6);
  transition: transform var(--dur-fast) var(--ease);
}
.fab:hover { transform: scale(1.08); }
.fab__hint {
  position: fixed; right: 88px; bottom: 38px; z-index: 90;
  font-size: 13px; color: var(--muted); background: #0c0c0c;
  border: 1px solid var(--border); border-radius: var(--r-full);
  padding: 7px 15px; opacity: 0; transform: translateX(8px);
  transition: all var(--dur-fast) var(--ease); pointer-events: none;
}
.fab:hover + .fab__hint { opacity: 1; transform: translateX(0); }

/* ---------- 20. 入场动效 ---------- */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  filter: blur(4px);
  transition: opacity var(--dur) var(--ease),
              transform var(--dur) var(--ease),
              filter var(--dur) var(--ease);
  will-change: opacity, transform;
}
.reveal.is-in { opacity: 1; transform: none; filter: blur(0); }
.reveal[data-delay="1"] { transition-delay: 80ms; }
.reveal[data-delay="2"] { transition-delay: 160ms; }
.reveal[data-delay="3"] { transition-delay: 240ms; }
.reveal[data-delay="4"] { transition-delay: 320ms; }
.reveal[data-delay="5"] { transition-delay: 400ms; }

/* ---------- 21. 响应式 ---------- */
@media (max-width: 1080px) {
  .grid--4 { grid-template-columns: repeat(2, 1fr); }
  .footer__grid { grid-template-columns: 1fr 1fr; gap: 34px; }
}
@media (max-width: 900px) {
  .nav__links, .nav__right .btn { display: none; }
  .nav__toggle { display: grid; }
  .split { grid-template-columns: 1fr; }
  .grid--3 { grid-template-columns: repeat(2, 1fr); }
  .stats { grid-template-columns: repeat(2, 1fr); }
  .stat:nth-child(2) { border-right: 0; }
  .stat:nth-child(1), .stat:nth-child(2) { border-bottom: 1px solid var(--border); }
}
@media (max-width: 640px) {
  :root { --nav-h: 66px; }
  .container { padding: 0 18px; }
  .grid--2, .grid--3, .grid--4 { grid-template-columns: 1fr; }
  .stats { grid-template-columns: 1fr; }
  .stat { border-right: 0; border-bottom: 1px solid var(--border); }
  .stat:last-child { border-bottom: 0; }
  .form__row { grid-template-columns: 1fr; }
  .matrix__row { grid-template-columns: 1fr; gap: 10px; }
  .footer__grid { grid-template-columns: 1fr; }
  .hero__bottom { flex-direction: column; align-items: flex-start; }
  .fab { right: 16px; bottom: 16px; }
}

/* ---------- 22. 无障碍 / 降低动效 ---------- */
@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;
  }
  .reveal { opacity: 1; transform: none; filter: none; }
  .word-reveal span { opacity: 1; color: var(--fg); }
}
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }
.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;
}

/* ==========================================================================
   点云 hero（原生 WebGL 模型渲染器）
   ========================================================================== */
.hero__cloud {
  position: absolute; inset: 0; z-index: 0;
  width: 100%; height: 100%;
  display: none;
  pointer-events: none;           /* 点击交给 hero 上的按钮，拖拽在 hero 上监听 */
}
html.has-cloud .hero__cloud { display: block; }
html.has-cloud .hero__fade { height: 32vh; }
html.has-cloud .hero__radial { opacity: 0.5; }

.cloud-panel {
  position: absolute; right: 24px; bottom: 104px; z-index: 3;
  width: 216px; padding: 14px 14px 10px;
  border-radius: 16px;
  background: rgba(8, 8, 8, 0.62);
  border: 1px solid var(--border);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  font-family: var(--font-mono);
  user-select: none;
}
.cloud-panel[hidden] { display: none; }
.cloud-panel__row { display: flex; align-items: center; gap: 8px; margin-top: 10px; }
.cloud-panel__model { justify-content: space-between; margin-top: 0; }
.cloud-panel__nav {
  width: 26px; height: 26px; border-radius: 50%; flex: 0 0 auto;
  border: 1px solid var(--border-strong); background: transparent;
  color: var(--fg); display: grid; place-items: center; cursor: pointer;
  transition: border-color var(--dur-fast) var(--ease), color var(--dur-fast) var(--ease);
}
.cloud-panel__nav:hover { border-color: var(--accent); color: var(--accent); }
.cloud-panel__nav .icon { width: 13px; height: 13px; }
.cloud-panel__meta { text-align: center; min-width: 0; }
.cloud-panel__idx { display: block; font-size: 10px; letter-spacing: 0.16em; color: var(--muted-2); }
.cloud-panel__name { display: block; font-size: 13px; color: var(--fg); font-family: var(--font-sans); margin-top: 3px; white-space: nowrap; }
.cloud-panel__latin { display: block; font-size: 9px; letter-spacing: 0.18em; color: var(--accent); margin-top: 3px; }
.cloud-panel__lab { font-size: 11px; color: var(--muted-2); flex: 0 0 auto; min-width: 44px; }
.cloud-panel__range {
  -webkit-appearance: none; appearance: none;
  flex: 1; height: 2px; border-radius: 2px; background: var(--border-strong); outline: none;
}
.cloud-panel__range::-webkit-slider-thumb {
  -webkit-appearance: none; width: 11px; height: 11px; border-radius: 50%;
  background: var(--accent); cursor: pointer; border: 0;
}
.cloud-panel__range::-moz-range-thumb { width: 11px; height: 11px; border: 0; border-radius: 50%; background: var(--accent); cursor: pointer; }
.cloud-panel__telemetry {
  justify-content: space-between; font-size: 10px; letter-spacing: 0.1em;
  color: var(--muted-2); border-top: 1px solid var(--border);
  padding-top: 9px; margin-top: 12px;
}
.cloud-panel__telemetry b { color: var(--fg); font-weight: 500; }
@media (max-width: 900px) {
  .cloud-panel { right: 16px; bottom: 88px; width: 186px; padding: 11px; }
}
@media (max-width: 560px) {
  /* 小屏只保留模型切换，滑杆与遥测收起，避免遮挡 */
  .cloud-panel { width: 168px; right: 12px; bottom: 80px; padding: 10px; }
  .cloud-panel__row:not(.cloud-panel__model) { display: none; }
}

/* 文字侧压暗遮罩：让点云保持体量，同时保证标题可读（比缩小模型更合理） */
html.has-cloud .hero::after {
  content: "";
  position: absolute; inset: 0; z-index: 1; pointer-events: none;
  background: linear-gradient(90deg,
    rgba(0, 0, 0, 0.86) 0%,
    rgba(0, 0, 0, 0.66) 30%,
    rgba(0, 0, 0, 0.30) 52%,
    rgba(0, 0, 0, 0) 70%);
}
@media (max-width: 900px) {
  /* 窄屏点云在中后方，改用径向遮罩压住中间文字区 */
  html.has-cloud .hero::after {
    background: radial-gradient(120% 78% at 50% 44%,
      rgba(0, 0, 0, 0.88) 0%,
      rgba(0, 0, 0, 0.66) 46%,
      rgba(0, 0, 0, 0.22) 74%,
      rgba(0, 0, 0, 0) 100%);
  }
}
/* ==========================================================================
   小屏修正（点云 hero 上线后暴露）
   ========================================================================== */
@media (max-width: 560px) {
  /* 导航：拉丁副标与语言名都会换行，小屏隐藏 */
  .nav__logo { gap: 6px; }
  .nav__logo-en { display: none; }
  .nav__lang-current { display: none; }
  .cloud-panel { display: none; }        /* 面板收起，改为自动轮播模型 */
  html.has-cloud .hero::after {
    background: radial-gradient(124% 80% at 50% 42%,
      rgba(0, 0, 0, 0.78) 0%,
      rgba(0, 0, 0, 0.56) 48%,
      rgba(0, 0, 0, 0.18) 76%,
      rgba(0, 0, 0, 0) 100%);
  }
}
/* ==========================================================================
   粒子牵拉线背景层（原版 2D 神经网络）+ 一页一模型的遮罩/面板定位
   ========================================================================== */
/* 固定背景层：顶部（hero 点云区）渐隐，往下才显现牵拉线 */
.pull-bg {
  position: fixed; inset: 0; z-index: 0;
  pointer-events: none; width: 100%; height: 100%;
  -webkit-mask-image: linear-gradient(180deg, transparent 0%, transparent 16%, rgba(0,0,0,0.5) 34%, #000 62%, #000 100%);
  mask-image: linear-gradient(180deg, transparent 0%, transparent 16%, rgba(0,0,0,0.5) 34%, #000 62%, #000 100%);
}
main, .footer { position: relative; z-index: 1; }

/* 内页：点云放在 page-head 内，需要同样的文字侧遮罩 */
html.has-cloud .page-head::after {
  content: ""; position: absolute; inset: 0; z-index: 1; pointer-events: none;
  background: linear-gradient(90deg, rgba(0,0,0,0.86) 0%, rgba(0,0,0,0.6) 34%, rgba(0,0,0,0.16) 62%, rgba(0,0,0,0) 84%);
}
html.has-cloud .page-head .cloud-panel { bottom: auto; top: 50%; transform: translateY(-50%); }
@media (max-width: 900px) {
  html.has-cloud .page-head::after {
    background: radial-gradient(120% 78% at 40% 50%, rgba(0,0,0,0.88) 0%, rgba(0,0,0,0.62) 46%, rgba(0,0,0,0.2) 76%, rgba(0,0,0,0) 100%);
  }
}
.cloud-panel[hidden] { display: none !important; }
/* ==========================================================================
   修复：点云压暗层必须待在文字之下
   .page-head__inner 原本是 z-index:1，与遮罩 ::after 同层，
   而伪元素排在子元素之后绘制 → 遮罩会糊在标题上（内页标题发暗的根因）。
   把内容提到 z-index:2 即可；首页 .hero__inner 本来就是 2，所以一直正常。
   ========================================================================== */
html.has-cloud .page-head__inner { z-index: 2; }
html.has-cloud .hero .scroll-hint { z-index: 2; }