/* ═══════════════════════════════════════════
   北京天略空间技术有限公司 — 官网样式
   Deep Space Tech Theme
   ═══════════════════════════════════════════ */

:root {
  --bg: #05070c;
  --bg-2: #0b1420;
  --line: rgba(120, 175, 225, 0.13);
  --line-strong: rgba(120, 175, 225, 0.26);
  --cyan: #4be1ff;
  --cyan-soft: rgba(75, 225, 255, 0.55);
  --text: #e8f0fb;
  --muted: #93a8c2;
  --dim: #6f85a0;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", "Helvetica Neue", sans-serif;
  --mono: ui-monospace, "SF Mono", "JetBrains Mono", Menlo, Consolas, monospace;
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);

  /* ── 流体布局：内容随浏览器宽度铺满并等比放大 ──
     以 1440px 为设计基准，所有关键尺寸用 vw 参与计算，
     视口变大 → 字号、间距、内边距同步变大，始终保持同一套视觉比例。 */
  --maxw: min(100%, 2720px);            /* 近乎铺满，仅挡住 5K 以上的极端超宽屏 */
  --gutter: clamp(20px, 3.3vw, 100px);  /* 左右安全边距 */
  --sec-pt: clamp(30px, 2.2vw, 56px);   /* 区块上留白：收紧，锚点跳转后标题不被空档推低 */
  --sec-pb: clamp(66px, 5.4vw, 140px);  /* 区块下留白：略小于原值，整体更紧凑 */
  --gap-lg: clamp(56px, 4.4vw, 118px);  /* 双栏大间距 */
  --cap-pad: clamp(26px, 2.15vw, 50px); /* 卡片内边距（大卡一档） */
}

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

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; background: var(--bg); }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 15.1px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

body::before {
  /* subtle global vignette */
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  background:
    radial-gradient(1100px 700px at 78% -8%, rgba(47, 107, 255, 0.10), transparent 62%),
    radial-gradient(900px 600px at 8% 12%, rgba(75, 225, 255, 0.05), transparent 60%);
}

img, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button { font-family: inherit; cursor: pointer; border: 0; background: none; color: inherit; }
ul { list-style: none; }

/* 中文断行：避免最后一行只剩一两个字（孤字行），放不下一整行时优先均分两行 */
p, li, dd, figcaption { text-wrap: pretty; }

.container {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 var(--gutter);
  position: relative;
  z-index: 1;
}

::selection { background: rgba(75, 225, 255, 0.25); color: #fff; }

/* ─── scrollbar ─── */
::-webkit-scrollbar { width: 10px; }
::-webkit-scrollbar-track { background: #05070c; }
::-webkit-scrollbar-thumb { background: #1b2a3d; border-radius: 6px; border: 2px solid #05070c; }
::-webkit-scrollbar-thumb:hover { background: #29405c; }

/* ═══════════ NAV ═══════════ */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  transition: background 0.4s var(--ease), border-color 0.4s var(--ease), backdrop-filter 0.4s;
  border-bottom: 1px solid transparent;
}
.nav.scrolled {
  background: rgba(5, 8, 14, 0.82);
  backdrop-filter: blur(18px) saturate(140%);
  -webkit-backdrop-filter: blur(18px) saturate(140%);
  border-bottom-color: var(--line);
}
.nav {
  background: rgba(5, 8, 14, 0.55);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}
.nav-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 var(--gutter);
  height: clamp(70px, 4.15vw, 92px);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

/* 品牌中文字体：只含「天略空间」四个字，2.2KB，避免整站换字体带来的体积与不一致 */
@font-face {
  font-family: "TL Brand";
  src: url("../fonts/brand-cn.woff2") format("woff2");
  font-weight: 400 800;
  font-display: swap;
  unicode-range: U+5929, U+7565, U+7A7A, U+95F4;
}

.brand { display: flex; align-items: center; gap: clamp(11px, 0.96vw, 17px); color: var(--cyan); }
/* 新符号为透明底 PNG（原图为白底 JPG，已去背并提亮为深底可见的钴蓝／橙），
   height:auto 防止宽高属性把比例拉变形 */
.brand-mark {
  width: clamp(34px, 2.8vw, 48px);
  height: auto;
  flex: none;
  filter: drop-shadow(0 0 11px rgba(62, 130, 224, 0.28));
  transition: filter 0.4s var(--ease);
}
.brand:hover .brand-mark { filter: drop-shadow(0 0 16px rgba(92, 156, 240, 0.46)); }
.brand-text { display: flex; flex-direction: column; line-height: 1.1; }
.brand-text strong {
  font-family: "TL Brand", var(--font);
  font-size: clamp(18.5px, 1.4vw, 26px);
  font-weight: 800;
  color: #eff7ff;
  letter-spacing: 0.09em;
  text-shadow: 0 0 26px rgba(120, 190, 255, 0.16);
}
.brand-text small {
  font-family: var(--mono);
  font-size: clamp(9.2px, 0.64vw, 12.2px);
  letter-spacing: 0.27em;
  color: #8498b1;
  text-transform: uppercase;
  margin-top: 4px;
}

.nav-links { display: flex; align-items: center; gap: clamp(24px, 2.35vw, 52px); }
.nav-links a {
  font-size: clamp(12.8px, 0.784vw, 17px);
  color: var(--muted);
  position: relative;
  padding: 6px 0;
  transition: color 0.25s;
  letter-spacing: 0.02em;
}
.nav-links a::after {
  content: "";
  position: absolute;
  left: 0; bottom: 0;
  width: 0; height: 1px;
  background: var(--cyan);
  transition: width 0.3s var(--ease);
  box-shadow: 0 0 8px var(--cyan-soft);
}
.nav-links a:hover, .nav-links a.active { color: var(--text); }
.nav-links a:hover::after, .nav-links a.active::after { width: 100%; }

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

.lang-btn {
  display: flex; align-items: center; gap: 5px;
  font-family: var(--mono); font-size: 12.1px; letter-spacing: 0.08em;
  color: var(--dim);
  padding: 6px 9px;
  border: 1px solid var(--line);
  border-radius: 3px;
  transition: border-color 0.25s, color 0.25s;
}
.lang-btn:hover { border-color: var(--line-strong); color: var(--muted); }
.lang-opt { transition: color 0.2s; }
.lang-opt.on { color: var(--cyan); }
.lang-sep { opacity: 0.35; }

.menu-btn {
  display: none;
  width: 34px; height: 34px;
  flex-direction: column; justify-content: center; gap: 5px;
  align-items: center;
}
.menu-btn span {
  display: block; width: 20px; height: 1.4px; background: var(--text);
  transition: transform 0.3s var(--ease), opacity 0.3s;
}
.menu-btn.open span:nth-child(1) { transform: translateY(3.2px) rotate(45deg); }
.menu-btn.open span:nth-child(2) { transform: translateY(-3.2px) rotate(-45deg); }

/* ═══════════ BUTTONS ═══════════ */
/* 统一「发丝描边 + 低透明度青玻璃」：不再用高饱和实心块，
   层级由描边强度与青光浓度区分，和卡片、图框的 1px 线条语言一致 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  font-size: clamp(13.2px, 0.945vw, 18px);
  font-weight: 500;
  padding: clamp(11px, 0.78vw, 16px) clamp(22px, 1.55vw, 34px);
  border-radius: 2px;
  border: 1px solid transparent;
  transition: color 0.3s var(--ease), background-color 0.3s var(--ease),
              border-color 0.3s var(--ease), box-shadow 0.3s var(--ease),
              transform 0.3s var(--ease);
  position: relative;
  letter-spacing: 0.06em;
  white-space: nowrap;
  -webkit-backdrop-filter: blur(6px);
  backdrop-filter: blur(6px);
}
.btn-arrow {
  width: clamp(14px, 0.86vw, 17.1px);
  height: clamp(14px, 0.86vw, 17.1px);
  transition: transform 0.3s var(--ease);
}
/* 键盘焦点环：UA 默认是 rgb(16,16,16)，在近黑背景上几乎不可见，必须显式给色 */
:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}
/* 表单控件的焦点反馈走 border + 光晕，不需要额外外框 */
.field input:focus-visible,
.field select:focus-visible,
.field textarea:focus-visible { outline: none; }

/* 主按钮：极淡的青色渐变玻璃 + 顶部内高光，悬停才点亮 */
.btn-primary {
  color: #dcf6ff;
  font-weight: 600;
  background:
    linear-gradient(180deg, rgba(75, 225, 255, 0.22), rgba(75, 225, 255, 0.07)),
    rgba(7, 16, 27, 0.62);
  border-color: rgba(75, 225, 255, 0.38);
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.12),
    inset 0 -1px 0 rgba(75, 225, 255, 0.20),
    0 14px 34px -24px rgba(0, 0, 0, 0.95);
}
.btn-primary::after {
  content: "";
  position: absolute; inset: 0;
  border-radius: inherit;
  background: linear-gradient(100deg, transparent 32%, rgba(130, 242, 255, 0.16) 50%, transparent 68%);
  opacity: 0;
  transition: opacity 0.45s var(--ease);
  pointer-events: none;
}
.btn-primary:hover {
  color: #eefdff;
  background:
    linear-gradient(180deg, rgba(75, 225, 255, 0.33), rgba(75, 225, 255, 0.11)),
    rgba(7, 16, 27, 0.62);
  border-color: rgba(75, 225, 255, 0.78);
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.15),
    0 0 0 1px rgba(75, 225, 255, 0.16),
    0 18px 42px -26px rgba(75, 225, 255, 0.85);
  transform: translateY(-1px);
}
.btn-primary:hover::after { opacity: 1; }
.btn-primary:hover .btn-arrow { transform: translateX(3px); }
.btn-primary:active { transform: translateY(0); }

/* 次按钮：更暗更轻，只做次要引导 */
.btn-ghost {
  color: rgba(212, 231, 250, 0.84);
  border-color: rgba(120, 175, 225, 0.20);
  background: rgba(8, 14, 22, 0.38);
}
.btn-ghost:hover {
  color: #fff;
  border-color: rgba(75, 225, 255, 0.46);
  background: rgba(75, 225, 255, 0.07);
  transform: translateY(-1px);
}

/* ═══════════ HERO ═══════════ */
.hero {
  --hero-pt: clamp(96px, 10.5vh, 150px);
  position: relative;
  padding: var(--hero-pt) 0 0;
  overflow: hidden;
  isolation: isolate;
  background: #05070c;
}
.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  overflow: hidden;
}
.hero-poster {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: 50% 100%;
  filter: brightness(1.14) saturate(1.06);
}
.hero-video {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: 50% 100%;
  /* 轻微放大：裁掉模型自带的角标，同时留出运镜余量 */
  transform: scale(1.08);
  opacity: 0;
  transition: opacity 1s linear;
  filter: brightness(1.06) saturate(1.04);
}
.hero-video.on { opacity: 1; }
/* 极细胶片颗粒：叠在视频之上，让画面更像实拍素材 */
.hero-bg::after {
  content: "";
  position: absolute;
  inset: -15%;
  pointer-events: none;
  opacity: 0.05;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='160' height='160' filter='url(%23n)'/%3E%3C/svg%3E");
  background-size: 160px 160px;
  animation: heroGrain 7s steps(6) infinite;
  will-change: transform;
}
@keyframes heroGrain {
  0%   { transform: translate3d(0, 0, 0); }
  16%  { transform: translate3d(-1.6%, 1.2%, 0); }
  33%  { transform: translate3d(1.4%, -1.4%, 0); }
  50%  { transform: translate3d(-1.2%, -1%, 0); }
  66%  { transform: translate3d(1.8%, 1.4%, 0); }
  83%  { transform: translate3d(-1.4%, 0.8%, 0); }
  100% { transform: translate3d(0, 0, 0); }
}
.noanim .hero-bg::after { animation: none; }
@media (prefers-reduced-motion: reduce) {
  .hero-bg::after { animation: none; }
}
.hero-veil {
  position: absolute;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  background:
    linear-gradient(102deg, rgba(5, 7, 12, 0.97) 0%, rgba(5, 7, 12, 0.95) 36%, rgba(5, 7, 12, 0.74) 57%, rgba(5, 7, 12, 0.32) 79%, rgba(5, 7, 12, 0.04) 100%),
    linear-gradient(180deg, rgba(5, 7, 12, 0.94) 0%, rgba(5, 7, 12, 0.42) 15%, rgba(5, 7, 12, 0) 34%, rgba(5, 7, 12, 0) 64%, rgba(5, 7, 12, 0.1) 84%, rgba(5, 7, 12, 0.36) 100%);
}
.hero::after {
  content: "";
  position: absolute;
  left: 0; right: 0; bottom: 0;
  height: 72px;
  z-index: 1;
  pointer-events: none;
  background: linear-gradient(180deg, rgba(5, 7, 12, 0) 0%, rgba(5, 7, 12, 0.5) 58%, #05070c 100%);
}
.hero .container { z-index: 2; }

.hero-inner {
  min-height: calc(100svh - var(--hero-pt));
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding-bottom: clamp(48px, 10vh, 130px);
}
.hero-copy { max-width: 100%; position: relative; }
/* 标题后方的一层冷光雾：让大字像从背景里发光，而不是贴在上面 */
.hero-copy::before {
  content: "";
  position: absolute;
  left: -13%; top: -30%;
  width: 90%; height: 104%;
  background:
    radial-gradient(44% 48% at 30% 42%, rgba(47, 107, 255, 0.085), rgba(47, 107, 255, 0) 68%),
    radial-gradient(36% 40% at 56% 64%, rgba(75, 225, 255, 0.055), rgba(75, 225, 255, 0) 70%);
  filter: blur(48px);
  pointer-events: none;
}

/* ── 首屏底部滚动提示：一条发丝线 + 一颗下坠的光点，无文字 ── */
.hero-scroll {
  position: absolute;
  left: 50%;
  bottom: clamp(22px, 3.6vh, 48px);
  z-index: 2;
  display: block;
  width: 2px;
  border-radius: 2px;
  height: clamp(34px, 4.6vh, 58px);
  transform: translateX(-50%);
  background: linear-gradient(180deg, rgba(120, 200, 255, 0) 0%, rgba(130, 210, 255, 0.62) 100%);
  transition: opacity 0.3s var(--ease);
}
.hero-scroll::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: -2px;
  width: 5px; height: 5px;
  border-radius: 50%;
  background: #b6f1ff;
  box-shadow: 0 0 8px rgba(140, 235, 255, 0.95), 0 0 18px rgba(90, 190, 255, 0.55);
  animation: hero-drop 2.6s cubic-bezier(0.4, 0, 0.5, 1) infinite;
}
@keyframes hero-drop {
  0%   { transform: translate(-50%, -44px); opacity: 0; }
  22%  { opacity: 1; }
  72%  { opacity: 1; }
  100% { transform: translate(-50%, 0); opacity: 0; }
}
.hero-scroll:hover { opacity: 0.55; }
@media (max-width: 720px) {
  .hero-scroll { display: none; }
}
@media (prefers-reduced-motion: reduce) {
  .hero-scroll::after { animation: none; opacity: 0.9; transform: translate(-50%, 0); }
}

.hero h1 {
  font-size: clamp(30.6px, 4.05vw, 99px);
  line-height: 1.18;
  font-weight: 600;
  letter-spacing: -0.02em;
  margin-bottom: 20px;
}
/* 第一行：银白→冰蓝的金属渐变 + 多层冷光投射 */
.hero h1 .hl {
  background: linear-gradient(178deg,
    #ffffff 0%, #ffffff 58%, #f4faff 76%,
    #d3e8ff 90%, #a9cdf2 96%, #e9f8ff 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  -webkit-text-stroke: 0.4px rgba(255, 255, 255, 0.45);
  color: transparent;
  filter:
    drop-shadow(0 1px 0 rgba(255, 255, 255, 0.45))
    drop-shadow(0 4px 12px rgba(8, 18, 34, 0.78))
    drop-shadow(0 14px 44px rgba(96, 172, 255, 0.20))
    drop-shadow(0 0 88px rgba(70, 140, 255, 0.13));
}
/* 第二行：青→蓝→紫的宽色域渐变，外加一道周期性扫过的高光 */
.hero h1 em {
  font-style: normal;
  display: block;
  white-space: nowrap;
  font-size: clamp(19.8px, 3.618vw, 88.2px);
  line-height: 1.14;
  margin-top: 0.12em;
  letter-spacing: -0.012em;
  background-image:
    linear-gradient(100deg, rgba(255, 255, 255, 0) 44%, rgba(255, 255, 255, 0.78) 50%, rgba(255, 255, 255, 0) 56%),
    linear-gradient(94deg,
      #8ef9ff 0%, #4ed5ff 16%, #57a4ff 38%,
      #a98bff 60%, #5ad4ff 82%, #8ef9ff 100%);
  background-size: 280% 100%, 100% 100%;
  background-position: -160% 50%, 0% 50%;
  background-repeat: no-repeat, no-repeat;
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  -webkit-text-stroke: 0.6px rgba(140, 226, 255, 0.30);
  filter:
    drop-shadow(0 3px 0 rgba(6, 12, 22, 0.42))
    drop-shadow(0 10px 32px rgba(75, 225, 255, 0.18))
    drop-shadow(0 0 68px rgba(47, 107, 255, 0.12));
  animation: hero-sheen 9s cubic-bezier(0.5, 0, 0.5, 1) infinite;
}
@keyframes hero-sheen {
  0%, 10%   { background-position: -160% 50%, 0% 50%; }
  62%, 100% { background-position: 160% 50%, 0% 50%; }
}
@media (prefers-reduced-motion: reduce) {
  .hero h1 em { animation: none; background-position: -220% 50%, 0% 50%; }
}
html[lang="en"] .hero h1 em {
  font-size: clamp(13.5px, 2.448vw, 61.2px);
  letter-spacing: -0.015em;
}

.hero-pos {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 26px;
  font-size: clamp(12.6px, 1.278vw, 24.3px);
  line-height: 1.4;
  font-weight: 600;
  letter-spacing: 0.26em;
  color: #e7f3ff;
  text-shadow: 0 2px 18px rgba(5, 7, 12, 0.85);
  text-indent: 0;
}
.hero-pos::before {
  content: "";
  flex: none;
  width: clamp(30px, 2.4vw, 54px);
  height: 1px;
  background: linear-gradient(90deg, var(--cyan), rgba(75, 225, 255, 0));
}
html[lang="en"] .hero-pos {
  font-family: var(--mono);
  font-weight: 500;
  letter-spacing: 0.22em;
  font-size: clamp(11.3px, 0.964vw, 18px);
  color: #b9d3e8;
}

/* 首屏正文：宽屏下强制单行展开，字号按视口宽度反算，
   「字号 × 79 字」恰好略窄于容器可用宽度（实测 100px → 7900px） */
/* 一行 90 字会拖到 1480px，阅读节奏太散；限宽约 1000px 折成两行 */
.hero-lead {
  font-size: clamp(11.7px, 1.026vw, 21.6px);
  line-height: 1.78;
  letter-spacing: 0.005em;
  color: var(--muted);
  max-width: min(100%, 1000px);
  text-wrap: pretty;
  margin-bottom: clamp(28px, 2.4vw, 46px);
}
html[lang="en"] .hero-lead {
  /* 英文 255 字符，100px → 11175px，需要单独一档更小的系数 */
  max-width: min(100%, 1060px);
  text-wrap: balance;
  font-size: clamp(10.4px, 0.765vw, 19.8px);
  letter-spacing: 0;
}

.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; margin-bottom: clamp(32px, 2.6vw, 54px); }

/* ═══════════ SECTION BASE ═══════════ */
.section { padding: var(--sec-pt) 0 var(--sec-pb); position: relative; }
/* 直接带 hash 打开时（JS 未介入）也按导航高度让位 */
.section { scroll-margin-top: clamp(70px, 4.15vw, 92px); }
.section-alt { background: linear-gradient(180deg, var(--bg-2), var(--bg)); }
.section-alt::before,
.section-alt::after {
  content: "";
  position: absolute; left: 0; right: 0; height: 1px;
  background: linear-gradient(90deg, transparent, var(--line-strong) 30%, var(--line-strong) 70%, transparent);
}
.section-alt::before { top: 0; }
.section-alt::after { bottom: 0; }

.sec-head { max-width: none; margin-bottom: clamp(17px, 1.55vw, 34px); }
/* 区块标题一律单行展开（中文最长 17 字 = 17 × 字号，可精确反算），
   字号沿用原比例，任何时候都不会顶到容器右缘 */
.sec-head h2 {
  font-size: clamp(18px, 2vw, 46px);
  white-space: nowrap;
  line-height: 1.3;
  font-weight: 600;
  letter-spacing: -0.015em;
  margin-bottom: 0;
}
/* 英文同一句最长 62 字符、约 29.6 字符宽/百字号 → 需单独收一档字号 */
html[lang="en"] .sec-head h2 {
  font-size: clamp(15.2px, 1.86vw, 42px);
  letter-spacing: -0.02em;
}

/* ═══════════ CAPABILITY ═══════════ */
.cap-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}
/* 三类卡片共用一套基底：渐变底 + 1px 描边 + hover 上浮投影 */
.cap-card {
  background: linear-gradient(165deg, rgba(16, 24, 38, 0.82), rgba(9, 14, 22, 0.64));
  border: 1px solid var(--line);
  padding: var(--cap-pad);
  position: relative;
  transition: border-color 0.4s var(--ease), transform 0.4s var(--ease),
              box-shadow 0.4s var(--ease), background 0.4s var(--ease);
  overflow: hidden;
}
.cap-card::before {
  content: "";
  position: absolute;
  top: 0; left: 0; right: 0; height: 1px;
  background: linear-gradient(90deg, transparent, var(--cyan), transparent);
  opacity: 0;
  transition: opacity 0.4s;
}
.cap-card:hover {
  background: linear-gradient(165deg, rgba(21, 31, 47, 0.9), rgba(11, 17, 26, 0.72));
  border-color: rgba(75, 225, 255, 0.28);
  transform: translateY(-3px);
  box-shadow: 0 22px 60px -20px rgba(0, 0, 0, 0.8), 0 0 0 1px rgba(75, 225, 255, 0.05);
}
.cap-card:hover::before { opacity: 1; }

/* 能力卡配图：通栏画幅，底部渐隐融入卡片 */
.cap-visual {
  position: relative;
  margin: calc(var(--cap-pad) * -1) calc(var(--cap-pad) * -1) clamp(22px, 1.9vw, 38px);
  overflow: hidden;
  background: #060a11;
}
.cap-visual img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  transform: scale(1.005);
  transition: transform 1.2s var(--ease);
}
.cap-card:hover .cap-visual img { transform: scale(1.055); }
.cap-visual::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(180deg,
    rgba(5, 8, 14, 0.42) 0%,
    rgba(5, 8, 14, 0) 26%,
    rgba(5, 8, 14, 0) 60%,
    rgba(5, 8, 14, 0.82) 100%);
}
.cap-card h3 {
  font-size: clamp(15.8px, 1.152vw, 22.5px);
  font-weight: 600;
  line-height: 1.5;
  margin-bottom: 14px;
  letter-spacing: 0.005em;
}
.cap-card p { font-size: clamp(12.5px, 0.907vw, 17.5px); line-height: 1.85; color: var(--muted); text-wrap: balance; }
.cap-line {
  position: absolute;
  bottom: 0; left: var(--cap-pad);
  width: 0; height: 1.5px;
  background: var(--cyan);
  transition: width 0.5s var(--ease);
}
.cap-card:hover .cap-line { width: 42px; }

/* ═══════════ PRODUCTS ═══════════ */
/* 四条产品线并排一行：卡片变窄，间距与内边距同步收一档，
   字号不动（仍是正文尺度），靠换行自然排布 */
.prod-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: clamp(11px, 1.05vw, 26px);
}
@media (max-width: 1319px) {
  .prod-grid { grid-template-columns: repeat(2, 1fr); gap: clamp(16px, 1.5vw, 30px); }
}
.prod-card {
  background: linear-gradient(165deg, rgba(16, 24, 38, 0.85), rgba(9, 14, 22, 0.7));
  border: 1px solid var(--line);
  overflow: hidden;
  position: relative;
  display: flex;
  flex-direction: column;
  transition: border-color 0.4s var(--ease), transform 0.4s var(--ease), box-shadow 0.4s;
}
.prod-card::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: radial-gradient(500px 200px at 50% 0%, rgba(75, 225, 255, 0.07), transparent 70%);
  opacity: 0;
  transition: opacity 0.4s;
}
.prod-card:hover {
  border-color: rgba(75, 225, 255, 0.28);
  transform: translateY(-3px);
  box-shadow: 0 22px 60px -20px rgba(0, 0, 0, 0.8), 0 0 0 1px rgba(75, 225, 255, 0.05);
}
.prod-card:hover::after { opacity: 1; }

.prod-visual {
  position: relative;
  overflow: hidden;
  border-bottom: 1px solid var(--line);
  background: #060a11;
  flex: none; /* 卡片是 flex 列，图区不能被文字挤压变形 */
}
.prod-visual img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  object-position: 50% 50%;
  transform: scale(1.005);
  transition: transform 1.2s var(--ease);
}
.prod-card:hover .prod-visual img { transform: scale(1.05); }
/* 上下渐隐 + 四角压暗，让图片融入卡片而不是贴上去 */
.prod-visual::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    linear-gradient(180deg, rgba(9, 14, 22, 0.55) 0%, rgba(9, 14, 22, 0) 20%, rgba(9, 14, 22, 0) 66%, rgba(9, 14, 22, 0.8) 100%),
    radial-gradient(130% 110% at 50% 50%, rgba(5, 8, 14, 0) 52%, rgba(5, 8, 14, 0.42) 100%);
}

.prod-body {
  padding: clamp(20px, 1.5vw, 32px) clamp(18px, 1.28vw, 26px) clamp(22px, 1.6vw, 34px);
  display: flex;
  flex-direction: column;
  flex: 1;
}
.prod-head { margin-bottom: 13px; }
.prod-head h3 {
  font-size: clamp(15.8px, 1.09vw, 21.2px);
  font-weight: 600;
  margin: 0;
  letter-spacing: 0.005em;
  line-height: 1.4;
}
.prod-desc {
  font-size: clamp(12.4px, 0.9vw, 17.4px);
  line-height: 1.75;
  color: var(--muted);
  padding-bottom: 18px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 18px;
}
.prod-list { display: flex; flex-direction: column; gap: 11px; }
.prod-list li {
  font-size: clamp(12.1px, 0.875vw, 16.6px);
  line-height: 1.72;
  color: #b3c5da;
  padding-left: 15px;
  position: relative;
}
.prod-list li::before {
  content: "";
  position: absolute;
  left: 0; top: 8px;
  width: 4px; height: 4px;
  border: 1px solid var(--cyan);
  transform: rotate(45deg);
  opacity: 0.75;
}
/* ═══════════ TECH STACK ═══════════ */
.tech-layout {
  display: grid;
  grid-template-columns: 0.88fr 1.12fr;
  gap: clamp(24px, 2.6vw, 56px);
}
.tech-visual {
  position: relative;
  margin: 0;
  display: flex;
  flex-direction: column;
  border: 1px solid var(--line);
  background: radial-gradient(120% 92% at 50% 42%, rgba(16, 34, 60, 0.85), rgba(6, 10, 17, 0.98) 72%);
  overflow: hidden;
  box-shadow: 0 20px 54px -32px rgba(0, 0, 0, 0.95);
}
.tech-visual::after {
  content: "";
  position: absolute;
  inset: 0;
  box-shadow: inset 0 0 62px rgba(4, 7, 12, 0.55);
  pointer-events: none;
}
.tech-visual img {
  display: block;
  width: 100%;
  height: auto;
  /* 保持原始画幅：裁成宽银幕会切掉最上面一层，四层必须完整 */
  height: auto;
  flex: none;
  filter: brightness(1.2) saturate(1.08) contrast(1.03);
  transform: scale(1.004);
  transition: transform 1.6s var(--ease), filter 0.6s;
}
.tech-visual:hover img { transform: scale(1.045); filter: brightness(1.28) saturate(1.12) contrast(1.04); }
/* 说明条叠在图片底部（图的下缘是空的深色），省掉一整条 60px 高度 */
.tech-visual figcaption {
  position: absolute;
  left: 0; right: 0; bottom: 0;
  z-index: 1;
  padding: clamp(20px, 1.8vw, 34px) clamp(16px, 1.25vw, 26px) clamp(12px, 0.9vw, 18px);
  background: linear-gradient(180deg, rgba(5, 8, 14, 0) 0%, rgba(5, 8, 14, 0.82) 62%, rgba(5, 8, 14, 0.94) 100%);
  display: flex;
  align-items: baseline;
  gap: 10px;
  flex-wrap: wrap;
}
.tv-idx {
  font-family: var(--mono);
  font-size: clamp(9.3px, 0.632vw, 11.9px);
  letter-spacing: 0.2em;
  color: var(--cyan);
  opacity: 0.9;
  white-space: nowrap;
}
.tv-txt {
  font-size: clamp(10.8px, 0.756vw, 14.2px);
  line-height: 1.5;
  color: #a8bed3;
}

.stack {
  display: flex;
  flex-direction: column;
  border: 1px solid var(--line);
  background: rgba(10, 16, 26, 0.5);
}
.stack-row {
  display: grid;
  grid-template-columns: clamp(185px, 11.3vw, 300px) 1fr;
  border-bottom: 1px solid var(--line);
  transition: background 0.3s;
  flex: 1 1 auto;
  background: linear-gradient(90deg, rgba(75, 225, 255, 0.035), rgba(75, 225, 255, 0) 40%);
}
.stack-row:last-child { border-bottom: 0; }
.stack-row:hover { background: linear-gradient(90deg, rgba(75, 225, 255, 0.075), rgba(75, 225, 255, 0.012) 55%); }
.stack-label {
  padding: clamp(20px, 1.6vw, 34px) clamp(18px, 1.45vw, 32px);
  border-right: 1px solid var(--line);
  display: flex;
  align-items: center;
  gap: clamp(10px, 0.82vw, 15px);
}
.stack-ico {
  width: clamp(16px, 1.12vw, 22px);
  height: auto;
  flex: none;
  color: var(--cyan);
  opacity: 0.7;
  transition: opacity 0.3s;
}
.stack-row:hover .stack-ico { opacity: 1; }
.stack-idx {
  font-family: var(--mono);
  font-size: clamp(10px, 0.699vw, 13.8px);
  color: var(--cyan);
  opacity: 0.6;
  letter-spacing: 0.08em;
  min-width: 1.9em;
}
.stack-label h3 { font-size: clamp(13.2px, 0.936vw, 18px); font-weight: 600; letter-spacing: 0.06em; white-space: nowrap; }
/* 六列网格：四层共用同一套列位，跨行对齐，行宽被填满
   （原来用 flex-wrap，每行右侧空出约 40%） */
.stack-body {
  padding: clamp(20px, 1.6vw, 34px) clamp(22px, 1.85vw, 40px);
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  align-items: center;
  gap: clamp(8px, 0.62vw, 13px);
}
.stack-body span {
  font-size: clamp(11.9px, 0.851vw, 16.6px);
  color: #b6c8dd;
  text-align: center;
  padding: 7px clamp(6px, 0.5vw, 11px);
  white-space: nowrap;
  border: 1px solid var(--line);
  border-radius: 2px;
  background: rgba(255, 255, 255, 0.012);
  transition: all 0.3s;
}
.stack-body span:hover {
  border-color: rgba(75, 225, 255, 0.35);
  color: var(--cyan);
  background: rgba(75, 225, 255, 0.05);
}
/* 英文标签长短差异大，等分网格会出现 3+1 的空档，改回按内容自然排列 */
html[lang="en"] .stack-body { display: flex; flex-wrap: wrap; gap: 9px; }
html[lang="en"] .stack-body span { white-space: normal; text-align: left; }
@media (max-width: 1180px) {
  .stack-body { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .stack-body span { white-space: normal; }
}
@media (max-width: 720px) {
  .stack-body { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  /* 窄屏图很矮，说明条叠加会压住最下层，恢复为独立一条 */
  .tech-visual figcaption {
    position: static;
    background: rgba(8, 13, 21, 0.55);
    border-top: 1px solid var(--line);
    padding: 14px 18px;
  }
}

html[lang="en"] .stack-body span {
  font-size: clamp(10.4px, 0.633vw, 13.2px);
  padding: 5px clamp(8px, 0.52vw, 11px);
  letter-spacing: 0;
  white-space: nowrap;
}

.tech-notes {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: clamp(18px, 1.65vw, 38px);
  margin-top: clamp(30px, 2.7vw, 58px);
}
.note {
  padding: clamp(22px, 1.85vw, 40px) clamp(24px, 1.95vw, 42px);
  border-left: 2px solid rgba(75, 225, 255, 0.3);
  background: linear-gradient(90deg, rgba(75, 225, 255, 0.04), transparent);
}
.note h3 { font-size: clamp(13.8px, 0.983vw, 18.9px); font-weight: 600; margin-bottom: 10px; letter-spacing: 0.03em; }
.note p { font-size: clamp(12.3px, 0.892vw, 17px); line-height: 1.8; color: var(--muted); }
.note-head { display: flex; align-items: center; gap: clamp(9px, 0.72vw, 14px); margin-bottom: clamp(9px, 0.72vw, 14px); }
.note-head h3 { margin-bottom: 0; }
.note-ico {
  width: clamp(18px, 1.26vw, 26px);
  height: auto;
  flex: none;
  color: var(--cyan);
  opacity: 0.82;
  transition: opacity 0.3s;
}
.note:hover .note-ico { opacity: 1; }

/* ═══════════ SCENARIOS ═══════════ */
.scene-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: clamp(12px, 0.9vw, 20px);
}
/* 3 列写不下时降为 2 列（与产品区同一断点），避免描述被挤成"只差一两个字"的折行 */
@media (max-width: 1319px) {
  .scene-grid { grid-template-columns: repeat(2, 1fr); }
}
.scene {
  --scene-pad: clamp(18px, 1.25vw, 33px);
  padding: var(--scene-pad);
  border: 1px solid var(--line);
  background: linear-gradient(165deg, rgba(16, 24, 38, 0.82), rgba(9, 14, 22, 0.64));
  transition: border-color 0.4s var(--ease), transform 0.4s var(--ease),
              box-shadow 0.4s var(--ease), background 0.4s var(--ease);
  position: relative;
  overflow: hidden;
}
.scene:hover {
  border-color: rgba(75, 225, 255, 0.28);
  background: linear-gradient(165deg, rgba(21, 31, 47, 0.9), rgba(11, 17, 26, 0.74));
  transform: translateY(-3px);
  box-shadow: 0 22px 60px -20px rgba(0, 0, 0, 0.8), 0 0 0 1px rgba(75, 225, 255, 0.05);
}
/* 场景插画：通栏出血，底部渐隐融进卡片 */
.scene-visual {
  position: relative;
  margin: calc(var(--scene-pad) * -1) calc(var(--scene-pad) * -1) clamp(18px, 1.5vw, 30px);
  overflow: hidden;
  background: #060a11;
}
.scene-visual img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  transform: scale(1.005);
  transition: transform 1.2s var(--ease);
}
.scene:hover .scene-visual img { transform: scale(1.055); }
.scene-visual::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(180deg,
    rgba(5, 8, 14, 0.40) 0%,
    rgba(5, 8, 14, 0) 30%,
    rgba(5, 8, 14, 0) 62%,
    rgba(5, 8, 14, 0.78) 100%);
}
.scene h3 { font-size: clamp(14.2px, 1.04vw, 19.8px); font-weight: 600; margin-bottom: 10px; line-height: 1.5; }
.scene p { font-size: clamp(11px, 0.85vw, 16px); line-height: 1.8; color: var(--muted); text-wrap: pretty; }

/* ═══════════ ABOUT ═══════════ */
.about-wrap {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: var(--gap-lg);
  align-items: start;
}
.about-copy h2 {
  text-wrap: balance;
  font-size: clamp(18px, 1.92vw, 42px);
  line-height: 1.32;
  font-weight: 600;
  margin-bottom: 30px;
  letter-spacing: -0.015em;
}
.about-copy p {
  font-size: clamp(13.8px, 1.002vw, 18.9px);
  line-height: 1.95;
  color: var(--muted);
  margin-bottom: 20px;
}
.values {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: clamp(18px, 1.6vw, 36px);
  margin-top: clamp(30px, 2.8vw, 58px);
  padding-top: clamp(26px, 2.3vw, 46px);
  border-top: 1px solid var(--line);
}
.value h3 {
  font-size: clamp(12.8px, 0.917vw, 17.5px);
  font-weight: 600;
  color: var(--cyan);
  margin-bottom: 9px;
  letter-spacing: 0.06em;
}
.value p { font-size: clamp(11.8px, 0.851vw, 16.1px); line-height: 1.75; color: var(--dim); margin: 0; }

/* 时间轴：细线自上而下渐隐，比等宽 1px 更能读出"进程"的意思 */
.timeline {
  position: relative;
  padding-left: 8px;
  border-left: 0;
}
.timeline::before {
  content: "";
  position: absolute;
  left: 0; top: 5px; bottom: 5px;
  width: 1px;
  background: linear-gradient(180deg,
    rgba(75, 225, 255, 0.55), rgba(120, 175, 225, 0.20) 46%, rgba(120, 175, 225, 0.06) 100%);
}
.tl-item {
  position: relative;
  padding: 0 0 clamp(26px, 2.3vw, 46px) clamp(22px, 1.9vw, 40px);
}
.tl-item:last-child { padding-bottom: 0; }
.tl-dot {
  position: absolute;
  left: -4.5px; top: 8px;
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--bg);
  border: 1.5px solid var(--cyan);
  box-shadow: 0 0 10px rgba(75, 225, 255, 0.5);
}
/* 桌面端让轴线一直延伸到左栏底部，右栏不再"悬在半空" */
@media (min-width: 1181px) {
  .about-wrap { align-items: stretch; }
  .about-side { display: flex; }
  .timeline { flex: 1; }
  .timeline::before { bottom: 0; }
}
.tl-item h3 { font-size: clamp(13.2px, 0.964vw, 18.5px); font-weight: 600; margin-bottom: 7px; letter-spacing: 0.03em; }
.tl-item p { font-size: clamp(12.1px, 0.869vw, 16.6px); line-height: 1.8; color: var(--muted); }

/* ═══════════ CONTACT ═══════════ */
.contact {
  background:
    radial-gradient(900px 500px at 85% 20%, rgba(47, 107, 255, 0.1), transparent 65%),
    linear-gradient(180deg, var(--bg), #04060a);
  border-top: 1px solid var(--line);
}
.contact-wrap {
  display: grid;
  grid-template-columns: 0.95fr 1.05fr;
  /* 行距单独收紧：标题与下方两栏靠得更近，列距保持原比例 */
  row-gap: clamp(34px, 3vw, 76px);
  column-gap: var(--gap-lg);
  align-items: start;
}
.contact-info h2 {
  text-wrap: balance;
  font-size: clamp(18px, 1.92vw, 42px);
  font-weight: 600;
  margin-bottom: 0;
  line-height: 1.3;
  letter-spacing: -0.015em;
}
/* 联系区：标题占满整行，其下才是「信息｜表单」两栏 */
.contact-info { grid-column: 1 / -1; }
/* 信息列表与右侧表单同高居中，避免左栏底部留空 */
.contact-list {
  display: flex; flex-direction: column;
  gap: clamp(22px, 2.4vw, 48px);
  align-self: start;
}
.contact-list li { display: flex; flex-direction: column; gap: 8px; }
/* 中文标签不能用等宽字体 + 宽字距：会显得比正文更小更散，与周围脱节 */
.cl-label {
  font-family: var(--font);
  font-size: clamp(12.2px, 0.847vw, 16.6px);
  font-weight: 500;
  letter-spacing: 0.06em;
  color: var(--muted);
  text-transform: uppercase;
}
html[lang="en"] .cl-label { font-size: clamp(11.4px, 0.8vw, 15.7px); letter-spacing: 0.1em; }
.cl-val { font-size: clamp(13.8px, 1.002vw, 18.9px); color: var(--text); letter-spacing: 0.01em; }
a.cl-val { text-decoration: none; transition: color 0.25s var(--ease); }
a.cl-val:hover { color: var(--cyan); }

.contact-form {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: clamp(15px, 1.25vw, 26px);
  padding: clamp(28px, 2.5vw, 54px) clamp(24px, 2.4vw, 52px);
  border: 1px solid var(--line);
  background: rgba(10, 16, 26, 0.6);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
}
.field { display: flex; flex-direction: column; gap: 8px; }
.field-full { grid-column: 1 / -1; }
.field label {
  font-size: clamp(12.2px, 0.847vw, 16.6px);
  font-weight: 500;
  color: var(--muted);
  letter-spacing: 0.06em;
}
.field input,
.field select,
.field textarea {
  font-family: inherit;
  font-size: clamp(12.8px, 0.917vw, 17.5px);
  color: var(--text);
  background: rgba(5, 9, 15, 0.8);
  border: 1px solid var(--line);
  border-radius: 2px;
  padding: clamp(10px, 0.76vw, 15px) clamp(12px, 0.9vw, 18px);
  outline: none;
  transition: border-color 0.25s, box-shadow 0.25s;
  width: 100%;
  resize: vertical;
}
.field select { -webkit-appearance: none; appearance: none; cursor: pointer; background-image: linear-gradient(45deg, transparent 50%, var(--dim) 50%), linear-gradient(135deg, var(--dim) 50%, transparent 50%); background-position: calc(100% - 18px) calc(50% + 1px), calc(100% - 13px) calc(50% + 1px); background-size: 5px 5px, 5px 5px; background-repeat: no-repeat; }
.field select option { background: #0a121d; color: var(--text); }
/* 原 #40556e 在 #05090f 上仅 2.61:1，占位提示几乎看不清 */
.field input::placeholder,
.field textarea::placeholder { color: #667e96; }
.field input:focus,
.field select:focus,
.field textarea:focus {
  border-color: rgba(75, 225, 255, 0.5);
  box-shadow: 0 0 0 3px rgba(75, 225, 255, 0.07);
}
.field input.err { border-color: rgba(255, 93, 108, 0.6); }

.form-foot {
  display: flex;
  align-items: center;
  gap: 18px;
  flex-wrap: wrap;
  margin-top: 6px;
}
.form-hint { font-size: 11.9px; color: var(--dim); line-height: 1.6; }
.form-hint.ok { color: var(--cyan); }

/* ═══════════ FOOTER ═══════════ */
.footer {
  border-top: 1px solid var(--line);
  padding: clamp(52px, 4.5vw, 96px) 0 clamp(26px, 2.2vw, 44px);
  background: #04060a;
}
.footer-inner {
  display: grid;
  grid-template-columns: 1.1fr 1.4fr;
  gap: clamp(44px, 3.8vw, 90px);
  padding-bottom: clamp(36px, 3.1vw, 66px);
}
.footer-brand .brand { margin-bottom: 20px; }
.footer-slogan {
  font-size: clamp(11.8px, 0.832vw, 16.1px);
  color: var(--dim);
  line-height: 1.9;
  max-width: clamp(320px, 24vw, 460px);
}
.footer-cols { display: grid; grid-template-columns: repeat(3, 1fr); gap: clamp(24px, 2vw, 44px); }
.footer-col { display: flex; flex-direction: column; gap: 11px; }
.footer-col h2 {
  font-family: var(--font);
  font-size: clamp(12.3px, 0.868vw, 17px);
  font-weight: 600;
  letter-spacing: 0.06em;
  color: #b3c7dd;
  text-transform: uppercase;
  margin-bottom: 9px;
}
html[lang="en"] .footer-col h2 {
  font-size: clamp(11.2px, 0.79vw, 15.5px);
  letter-spacing: 0.11em;
}
.footer-col a, .footer-col span {
  font-size: clamp(11.9px, 0.851vw, 16.6px);
  color: var(--dim);
  transition: color 0.25s;
  line-height: 1.6;
}
.footer-col a:hover { color: var(--cyan); }
.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 20px;
  padding-top: clamp(18px, 1.5vw, 30px);
  border-top: 1px solid var(--line);
  font-size: clamp(10.8px, 0.756vw, 14.7px);
  color: #667e96;
  flex-wrap: wrap;
}
.footer-icp { font-family: var(--mono); letter-spacing: 0.04em; color: inherit; text-decoration: none; transition: color .3s; }
.footer-icp:hover { color: var(--cyan); }
.footer-icp[hidden] { display: none; }

.to-top {
  position: fixed;
  right: clamp(16px, 1.6vw, 34px); bottom: clamp(16px, 1.6vw, 34px);
  width: clamp(42px, 2.9vw, 56px); height: clamp(42px, 2.9vw, 56px);
  display: grid;
  place-items: center;
  border: 1px solid var(--line-strong);
  background: rgba(8, 13, 21, 0.85);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  color: var(--muted);
  border-radius: 3px;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: all 0.35s var(--ease);
  z-index: 90;
}
.to-top.show { opacity: 1; visibility: visible; transform: none; }
.to-top:hover { color: var(--cyan); border-color: var(--cyan-soft); }
.to-top svg { width: clamp(16px, 1.1vw, 21px); height: clamp(16px, 1.1vw, 21px); }

/* ═══════════ REVEAL ANIMATION ═══════════ */
.reveal {
  opacity: 0;
  transform: translateY(26px);
  transition: opacity 0.85s var(--ease), transform 0.85s var(--ease);
  transition-delay: calc(var(--i, 0) * 70ms);
}
.reveal.in { opacity: 1; transform: none; }

/* 静态渲染模式（?noanim=1，用于截图与打印） */
.noanim .reveal { opacity: 1 !important; transform: none !important; transition: none !important; }

@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  html { scroll-behavior: auto; }
}

/* ═══════════ RESPONSIVE ═══════════ */
@media (max-width: 1600px) {
  .tech-layout { grid-template-columns: 1fr; gap: clamp(24px, 2.6vw, 40px); }
  /* 图与下方表格必须左右对齐，否则整块看起来是"图浮在中间、表铺满全宽" */
  .tech-visual { justify-self: stretch; width: 100%; max-width: none; }
}

@media (max-width: 1180px) {
  .hero { --hero-pt: clamp(92px, 10vh, 120px); }
  .hero h1 { font-size: clamp(30.6px, 4.86vw, 61.2px); }
  .hero-copy { max-width: 100%; }
  .about-wrap, .contact-wrap { grid-template-columns: 1fr; gap: 56px; }
  .cap-grid { grid-template-columns: repeat(2, 1fr); }
  .scene-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-inner { grid-template-columns: 1fr; gap: 44px; }
}

@media (max-width: 900px) {
  .nav-links {
    position: fixed;
    top: 70px; left: 0; right: 0;
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
    padding: 8px 32px 24px;
    background: rgba(5, 8, 14, 0.97);
    -webkit-backdrop-filter: blur(20px);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--line);
    transform: translateY(-12px);
    opacity: 0;
    visibility: hidden;
    transition: all 0.32s var(--ease);
  }
  .nav-links.open { transform: none; opacity: 1; visibility: visible; }
  .nav-links a { padding: 15px 0; font-size: 14.2px; width: 100%; border-bottom: 1px solid rgba(120,175,225,.07); }
  .menu-btn { display: flex; }
  .prod-grid { grid-template-columns: 1fr; }
  .tech-notes { grid-template-columns: 1fr; }
  .stack-row { grid-template-columns: 1fr; }
  .stack-label { border-right: 0; border-bottom: 1px solid var(--line); padding: 18px 22px; }
  .stack-body { padding: 18px 22px; }
  .contact-form { padding: 28px 24px; }
}

@media (max-width: 720px) {
  .container { padding: 0 20px; }
  .hero-bg img { object-position: 60% bottom; }
  .hero-inner { padding-bottom: 96px; }
  html[lang="en"] .hero h1 em { white-space: normal; font-size: 18px; line-height: 1.3; }
  .hero h1 em { font-size: clamp(18px, 5.535vw, 21.6px); letter-spacing: -0.02em; }
  .hero-veil {
    background:
      linear-gradient(180deg, rgba(5, 7, 12, 0.9) 0%, rgba(5, 7, 12, 0.62) 26%, rgba(5, 7, 12, 0.16) 56%, rgba(5, 7, 12, 0.3) 78%, rgba(5, 7, 12, 0.78) 100%);
  }
  .nav-inner { padding: 0 20px; height: 68px; }
  .nav-links { top: 68px; padding: 8px 20px 20px; }
  .hero { --hero-pt: 92px; }
  .cap-grid { grid-template-columns: 1fr; }
  .cap-card { padding: 26px 22px; }
  .cap-visual { margin: -26px -22px 20px; }
  .scene-grid { grid-template-columns: 1fr; }
  .values { grid-template-columns: 1fr; gap: 18px; }
  .contact-form { grid-template-columns: 1fr; }
  .footer-cols { grid-template-columns: 1fr 1fr; gap: 28px 20px; }
  /* 第三列内容最宽（邮箱/地址），跨满整行，避免只剩左半屏 */
  .footer-col:nth-child(3) { grid-column: 1 / -1; }
  .footer-bottom { flex-direction: column; align-items: flex-start; gap: 8px; }
  .hero-actions { gap: 12px; }
  .hero-actions .btn { flex: 1 1 auto; }
  .prod-body { padding: 26px 22px 28px; }
  .sec-head { margin-bottom: 16px; }
  .to-top { right: 16px; bottom: 16px; }
  /* .container 的 padding 简写会清掉 .footer-inner 的下内边距 */
  .footer-inner { padding-bottom: 30px; }
}

@media (max-width: 420px) {
  .brand-text small { font-size: 8.4px; }
}

/* ═══════════ HERO LEAD：窄屏恢复自动换行 ═══════════
   宽度不足 1240 时若仍强制单行，字号会被压到 14px 以下且行长达一整屏，
   反而难读，因此以下恢复多行排版并放宽行宽上限 */
/* 1139 以下字号会跌破 13px，且双行版每行约 66 字、尾行仍有十余字，不会出现孤字 */
@media (max-width: 1139px) {
  .hero-lead {
    white-space: normal;
    font-size: 14.7px;
    line-height: 1.85;
    letter-spacing: 0.01em;
    max-width: 100%;
  }
}

/* 英文段落 255 字符，单行需要近 12px 字号，1600 以下允许换成两行，保持可读 */
@media (max-width: 1599px) {
  html[lang="en"] .hero-lead {
    white-space: normal;
    font-size: 14.2px;
    line-height: 1.72;
    letter-spacing: 0;
    max-width: 100%;
  }
}

@media (max-width: 720px) {
  html[lang="en"] .hero-lead { font-size: 13.8px; }
}

/* ═══════════ 区块标题：窄屏恢复换行 ═══════════
   中文 17 字在 28px 下需 476px，视口低于 560 时容不下单行；
   英文 62 字符在 24px 下需 711px，低于 820 时容不下单行 */
@media (max-width: 820px) {
  html[lang="en"] .sec-head h2 {
    white-space: normal;
    text-wrap: balance;
    font-size: clamp(14.6px, 2.55vw, 20px);
  }
}

@media (max-width: 560px) {
  .sec-head h2 { white-space: normal; text-wrap: balance; }
}

/* 标点后的换行点：桌面单行时隐藏，窄屏才生效，避免把词拆开 */
br.only-m { display: none; }
@media (max-width: 560px) {
  .sec-head h2 br.only-m { display: inline; }
}