@charset "utf-8";
/* ============================================================
   MILITEC · ONE SURFACE 设计系统
   接管原 ui.css 的全部选择器，16 个内页可零改动套用。
   原则：1 个强调色、1 条动效曲线、超细字重 + 疏排、细边框替代阴影。
   ============================================================ */

/* ---------------- TOKENS ---------------- */
:root{
  /* 旧变量全部保留，内页不改动也能跑 */
  --red:#cc0000; --rl:#e60000; --rd:#990000;
  --g50:#f9f9f9; --g100:#f0f0f0; --g200:#e0e0e0;
  --g400:#999; --g600:#666; --g800:#333; --g900:#1a1a1a;

  /* 新令牌 */
  --ink:#0B0B0D;          /* 金属黑，深色区背景 */
  --ink-soft:#14161A;
  --paper:#F7F7F8;        /* 近白 */
  --paper-dim:#EDEDEE;
  --metal-900:#2C2F34;
  --metal-700:#5B6067;
  --metal-500:#7D838A;
  --metal-300:#9AA0A6;

  --line:rgba(0,0,0,.09);
  --line-dark:rgba(255,255,255,.13);

  --ease:cubic-bezier(.16,1,.3,1);
  --dur-fast:200ms;
  --dur:800ms;

  --col:1200px;           /* 内容列宽，比原 1000px 宽，给 3D 留空间 */
  --gut:40px;
  --nav-h:64px;
}

/* ---------------- BASE ---------------- */
*,*::before,*::after{ box-sizing:border-box; }
html{ -webkit-text-size-adjust:100%; scroll-behavior:smooth; }
body{
  margin:0; background:var(--paper); color:var(--g900);
  font-family:"PingFang SC","Hiragino Sans GB","Microsoft YaHei",
              -apple-system,BlinkMacSystemFont,"Segoe UI",Inter,system-ui,sans-serif;
  font-size:16px; line-height:1.8; font-weight:400;
  -webkit-font-smoothing:antialiased; text-rendering:optimizeLegibility;
  overflow-x:hidden;
}
img{ max-width:100%; display:block; border:0; }
a{ color:inherit; text-decoration:none; }
button{ font-family:inherit; }
::selection{ background:var(--red); color:#fff; }

/* 数字统一等宽，跳动时不错位 */
.trust-num,.stat-value,.counter,.bf-cov b,.eg-mv{ font-variant-numeric:tabular-nums; }

/* ---------------- LAYOUT ---------------- */
.container{ width:100%; max-width:var(--col); margin:0 auto; padding:0 var(--gut); }
.section{ padding:120px 0; position:relative; }
.section-inner{ max-width:var(--col); margin:0 auto; padding:0 var(--gut); }

/* ---------------- TYPOGRAPHY ---------------- */
/* 超细字重 + 疏排 = 工业精密感 */
.section-head{ margin-bottom:56px; }
.section-label{
  font-size:11px; font-weight:500; color:var(--red);
  letter-spacing:.28em; text-transform:uppercase; margin-bottom:18px;
}
.section-title{
  font-size:clamp(30px,4.4vw,52px); font-weight:200; color:var(--g900);
  line-height:1.25; letter-spacing:.02em; margin:0 0 20px;
}
.section-title strong{ font-weight:500; }
.section-desc{
  color:var(--g600); font-size:17px; line-height:1.85;
  max-width:620px; margin:0; font-weight:300;
}

.prose p{ color:var(--g600); line-height:1.9; margin:0 0 18px; font-weight:300; }
.prose h3{
  font-size:21px; font-weight:400; color:var(--g900);
  margin:40px 0 16px; letter-spacing:.02em;
}
.prose ul{ list-style:none; padding:0; margin:0 0 20px; }
.prose ul li{
  position:relative; padding-left:22px; margin-bottom:10px;
  color:var(--g600); font-weight:300; line-height:1.85;
}
.prose ul li::before{
  content:""; position:absolute; left:0; top:.78em;
  width:8px; height:1px; background:var(--red);
}

/* ---------------- BUTTONS ---------------- */
.btn{
  display:inline-flex; align-items:center; justify-content:center; gap:8px;
  padding:13px 30px; border-radius:2px; border:1px solid var(--g200);
  background:transparent; color:var(--g900);
  font-size:14px; font-weight:400; letter-spacing:.06em; cursor:pointer;
  transition:all var(--dur-fast) var(--ease);
}
.btn:hover{ border-color:var(--g900); }
.btn-primary{
  background:var(--red); border-color:var(--red); color:#fff;
}
.btn-primary:hover{ background:var(--rd); border-color:var(--rd); }
.btn-ghost{ background:transparent; border-color:rgba(255,255,255,.28); color:#fff; }
.btn-ghost:hover{ border-color:#fff; background:rgba(255,255,255,.06); }
.btn-lg{ padding:16px 42px; font-size:15px; }
.btn-block{ display:flex; width:100%; }

/* ---------------- NAV（.sn-* 由 nav.js 生成，结构不可改）---------------- */
.sn-navbar{
  position:sticky; top:0; z-index:200;
  background:rgba(247,247,248,.86); backdrop-filter:saturate(180%) blur(20px);
  border-bottom:1px solid var(--line);
}
.sn-inner{
  max-width:var(--col); margin:0 auto; padding:0 var(--gut);
  height:var(--nav-h); display:flex; align-items:center; gap:20px;
}
.sn-logo{ display:flex; align-items:center; gap:10px; flex:none; }
.sn-logo img{ height:26px; width:auto; }
.sn-logo-mark{
  font-size:16px; font-weight:500; letter-spacing:.16em; color:var(--g900);
  display:flex; align-items:baseline; gap:3px;
}
.sn-logo-mark small{ font-size:11px; letter-spacing:.1em; color:var(--g600); }
.sn-logo-mark sup{ font-size:8px; color:var(--red); }
.sn-divider{ width:1px; height:20px; background:var(--line); flex:none; }

.sn-links{ display:flex; align-items:center; gap:4px; margin:0; padding:0; list-style:none; }
.sn-links a{
  display:inline-block; padding:8px 14px; border-radius:2px;
  font-size:13.5px; font-weight:300; color:var(--g600);
  letter-spacing:.04em; position:relative;
  transition:color var(--dur-fast) var(--ease);
}
.sn-links a:hover{ color:var(--g900); }
.sn-links a.active{ color:var(--g900); font-weight:400; }
.sn-links a.active::after{
  content:""; position:absolute; left:14px; right:14px; bottom:2px;
  height:1.5px; background:var(--red);
}
.sn-links a.sn-cta{
  color:#fff; background:var(--red); padding:9px 20px; margin-left:6px;
  font-weight:400;
}
.sn-links a.sn-cta:hover{ background:var(--rd); }
.sn-links a.sn-cta.active::after{ display:none; }
.sn-divider-cta{ width:1px; height:20px; background:var(--line); flex:none; }

.sn-dropdown{ position:relative; }
.sn-dropdown > a{ display:inline-flex; align-items:center; gap:5px; cursor:pointer; }
.sn-caret{
  width:5px; height:5px; border-right:1px solid currentColor;
  border-bottom:1px solid currentColor; transform:rotate(45deg) translateY(-1px);
  opacity:.55; transition:transform var(--dur-fast) var(--ease);
}
.sn-dropdown:hover .sn-caret{ transform:rotate(225deg) translateY(-1px); }
.sn-submenu{
  position:absolute; top:100%; left:0; min-width:212px;
  background:#fff; border:1px solid var(--line); border-radius:4px;
  padding:7px; list-style:none; margin:6px 0 0;
  box-shadow:0 18px 48px rgba(0,0,0,.10);
  opacity:0; visibility:hidden; transform:translateY(-6px);
  transition:all var(--dur-fast) var(--ease);
}
.sn-dropdown:hover .sn-submenu,
.sn-submenu.show{ opacity:1; visibility:visible; transform:translateY(0); }
.sn-submenu a{
  display:block; padding:9px 13px; border-radius:3px;
  font-size:13.5px; color:var(--g600); font-weight:300;
}
.sn-submenu a:hover{ background:var(--g50); color:var(--g900); }

.sn-right{ margin-left:auto; display:flex; align-items:center; gap:12px; flex:none; }
.sn-lang{ position:relative; }
.sn-lang-btn{
  display:inline-flex; align-items:center; gap:6px;
  padding:7px 12px; border:1px solid var(--line); border-radius:2px;
  background:transparent; cursor:pointer;
  font-size:12.5px; color:var(--g600); letter-spacing:.04em;
  transition:border-color var(--dur-fast) var(--ease);
}
.sn-lang-btn:hover{ border-color:var(--g400); }
.sn-flag{ font-size:13px; line-height:1; }
.sn-arrow{
  width:5px; height:5px; border-right:1px solid currentColor;
  border-bottom:1px solid currentColor; transform:rotate(45deg) translateY(-1px); opacity:.5;
}
.sn-lang-menu{
  position:absolute; top:calc(100% + 6px); right:0; min-width:150px;
  background:#fff; border:1px solid var(--line); border-radius:4px;
  padding:6px; list-style:none; margin:0;
  box-shadow:0 18px 48px rgba(0,0,0,.10);
  opacity:0; visibility:hidden; transform:translateY(-6px);
  transition:all var(--dur-fast) var(--ease);
}
.sn-lang-menu.show{ opacity:1; visibility:visible; transform:translateY(0); }
.sn-lang-menu a{ display:block; padding:8px 12px; border-radius:3px; font-size:13px; color:var(--g600); }
.sn-lang-menu a:hover{ background:var(--g50); color:var(--g900); }
.sn-toggle{ display:none; }

/* ---------------- 产品卡 ---------------- */
.ucard{
  background:#fff; border:1px solid var(--line); border-radius:4px;
  overflow:hidden; transition:all var(--dur-fast) var(--ease);
}
.ucard:hover{ border-color:var(--g200); transform:translateY(-3px); box-shadow:0 16px 44px rgba(0,0,0,.07); }
.ucard-thumb{ background:var(--g50); aspect-ratio:4/3; overflow:hidden; }
.ucard-thumb img{ width:100%; height:100%; object-fit:cover; }
.ucard h3{ font-size:17px; font-weight:400; margin:20px 24px 6px; letter-spacing:.02em; }
.ucard .model{ font-size:12px; color:var(--g400); letter-spacing:.06em; margin:0 24px 14px; }
.ucard .spec-list{ list-style:none; margin:0 24px 14px; padding:0; }
.ucard .spec-list li{
  display:flex; justify-content:space-between; gap:12px;
  padding:7px 0; border-top:1px solid var(--g100); font-size:13px;
}
.ucard .spec-list li .k{ color:var(--g400); flex:none; }
.ucard .spec-list li .v{ color:var(--g900); text-align:right; }
.ucard .desc{ color:var(--g600); font-size:13.5px; line-height:1.75; margin:0 24px; font-weight:300; }
.ucard .btn{ margin:18px 24px 24px; }

/* ---------------- 制造商背书 ---------------- */
.proof{ background:var(--g50); }
.proof-head{ text-align:center; margin-bottom:56px; }
.proof-cols{ display:grid; grid-template-columns:repeat(auto-fit,minmax(280px,1fr)); gap:40px; }
.mfg-group{ list-style:none; margin:0; padding:0; }
.mfg-cat{
  font-size:11px; letter-spacing:.2em; text-transform:uppercase;
  color:var(--red); margin-bottom:18px; display:flex; align-items:center; gap:10px;
}
.mfg-cat::before{ content:""; width:14px; height:1px; background:var(--red); flex:none; }
.mfg-chips{ display:flex; flex-wrap:wrap; gap:8px; list-style:none; margin:0; padding:0; }
.mfg-chips span{
  display:inline-block; padding:7px 14px; background:#fff;
  border:1px solid var(--line); border-radius:2px;
  font-size:13px; color:var(--g800); letter-spacing:.02em;
  transition:border-color var(--dur-fast) var(--ease);
}
.mfg-chips span:hover{ border-color:var(--red); }
.proof-cert h3{ font-size:19px; font-weight:400; margin:0 0 12px; }
.proof-cert p{ color:var(--g600); font-size:14px; font-weight:300; margin:0 0 22px; }
.proof-list{ list-style:none; margin:0; padding:0; }
.proof-list li{
  position:relative; padding-left:20px; margin-bottom:11px;
  color:var(--g600); font-size:14px; font-weight:300;
}
.proof-list li::before{
  content:""; position:absolute; left:0; top:.8em; width:7px; height:1px; background:var(--red);
}

/* ---------------- 数据条 ---------------- */
.trust-strip{ background:var(--ink); padding:64px 0; }
.trust-strip .trust-grid{
  max-width:var(--col); margin:0 auto; padding:0 var(--gut);
  display:grid; grid-template-columns:repeat(auto-fit,minmax(150px,1fr)); gap:28px;
}
.trust-item{ text-align:center; }
.trust-item:first-child{ border-left:0; }
.trust-num{
  font-size:clamp(30px,3.6vw,44px); font-weight:200; color:#fff;
  line-height:1.1; letter-spacing:.01em;
}
.trust-num .accent{ color:var(--red); font-weight:400; }
.trust-label{
  font-size:11.5px; color:rgba(255,255,255,.5);
  letter-spacing:.18em; text-transform:uppercase; margin-top:12px;
}

/* ---------------- 页脚 ---------------- */
.site-footer{ background:var(--ink); color:rgba(255,255,255,.62); padding:80px 0 0; font-size:13.5px; }
.site-footer .container{ max-width:var(--col); padding:0 var(--gut); }
.ft-grid{ display:grid; grid-template-columns:1.6fr 1fr 1fr 1.2fr; gap:44px; padding-bottom:56px; }
.ft-brand{ color:#fff; font-size:17px; font-weight:400; letter-spacing:.2em; margin:0 0 14px; }
.ft-brand span{ display:block; }
.ft-tag{ color:rgba(255,255,255,.4); font-size:12.5px; line-height:1.8; font-weight:300; margin:0; }
.ft-col h4{
  color:#fff; font-size:11px; font-weight:500; letter-spacing:.2em;
  text-transform:uppercase; margin:0 0 18px;
}
.ft-col a,.ft-col p{ color:rgba(255,255,255,.62); font-size:13.5px; line-height:2; margin:0; display:block; font-weight:300; }
.ft-col a:hover{ color:#fff; }
.ft-cols-links a{ display:block; }
.ft-bottom{
  border-top:1px solid var(--line-dark); padding:22px 0 30px;
  display:flex; justify-content:space-between; align-items:center; gap:16px;
  flex-wrap:wrap; font-size:12px; color:rgba(255,255,255,.36);
}
.ft-bottom a{ color:rgba(255,255,255,.5); }
.ft-bottom a:hover{ color:#fff; }
.footer-logo{ height:22px; margin-bottom:14px; }
.footer-logo span{ display:none; }
.footer-firm{ font-size:12px; line-height:1.9; color:rgba(255,255,255,.4); }

.official-link{
  display:inline-flex; align-items:center; gap:8px; color:var(--red);
  font-size:13px; letter-spacing:.04em; position:relative;
}
.official-link::after{
  content:""; position:absolute; left:0; bottom:-3px; width:100%; height:1px;
  background:var(--red); transform:scaleX(0); transform-origin:left;
  transition:transform var(--dur-fast) var(--ease);
}
.official-link:hover::after{ transform:scaleX(1); }

/* ============================================================
   ONE SURFACE · 尺度轴
   ============================================================ */

/* 舞台：滚动叙事的容器 */
.os-stage{ position:relative; background:var(--ink); }

/* 视口：sticky 的画布层，高度由 --os-h 控制 */
.os-viewport{
  position:sticky; top:var(--nav-h);
  height:calc(100vh - var(--nav-h)); min-height:520px;
  overflow:hidden; z-index:0;
}
.os-viewport canvas{ position:absolute; inset:0; width:100%; height:100%; display:block; }

/* 文字层：叠在画布上，随进度交替 */
.os-track{ position:relative; z-index:2; margin-top:calc(-100vh + var(--nav-h)); }
.os-chapter{
  /* 每个尺度要留够滚动余量，否则四个尺度一晃就过去了。
     但又不能太高：章节高 - 视口高 = 文字不可见的空档，
     这段空白正好落在层与层之间的推近转场里，超过一屏就变成空洞。 */
  min-height:120vh; display:flex; align-items:center;
  padding:0 var(--gut); pointer-events:none;
}
.os-chapter-inner{
  max-width:520px; pointer-events:auto;
  opacity:0; transform:translateY(24px);
  transition:opacity var(--dur) var(--ease), transform var(--dur) var(--ease);
  will-change:opacity,transform;
}
.os-chapter.on .os-chapter-inner{ opacity:1; transform:none; }

.os-scale{
  font-size:11px; letter-spacing:.3em; text-transform:uppercase;
  color:var(--red); margin-bottom:16px;
  display:flex; align-items:center; gap:10px;
}
.os-scale::before{ content:""; width:22px; height:1px; background:var(--red); }
.os-chapter h2{
  font-size:clamp(26px,3.2vw,40px); font-weight:200; color:#fff;
  line-height:1.3; letter-spacing:.02em; margin:0 0 18px;
}
.os-chapter p{
  color:rgba(255,255,255,.6); font-size:16px; line-height:1.9;
  font-weight:300; margin:0 0 14px;
}
.os-note{ font-size:12px; color:rgba(255,255,255,.34); letter-spacing:.03em; }

/* 章节靠右排布，避免永远压在同一侧 */
.os-chapter.right{ justify-content:flex-end; }
.os-chapter.right .os-chapter-inner{ text-align:left; }

/* 尺度进度指示器 */
.os-rail{
  position:fixed; right:26px; top:50%; transform:translateY(-50%);
  z-index:30; display:flex; flex-direction:column; gap:14px;
  opacity:0; transition:opacity var(--dur) var(--ease); pointer-events:none;
}
.os-rail.on{ opacity:1; }
.os-rail i{
  display:block; width:1px; height:26px; background:rgba(255,255,255,.22);
  position:relative; transition:background var(--dur-fast) var(--ease);
}
.os-rail i.on{ background:var(--red); }
.os-rail i.on::after{
  content:attr(data-s); position:absolute; right:14px; top:50%;
  transform:translateY(-50%); font-size:10px; letter-spacing:.12em;
  color:var(--red); white-space:nowrap; font-style:normal;
}

/* 序章与尾声：浅色 */
.os-intro{
  min-height:92vh; display:flex; flex-direction:column;
  align-items:center; justify-content:center; text-align:center;
  padding:0 var(--gut); background:var(--ink); position:relative; z-index:2;
}
.os-badge{
  display:inline-block; font-size:11px; letter-spacing:.26em;
  text-transform:uppercase; color:rgba(255,255,255,.42);
  border:1px solid var(--line-dark); padding:6px 14px;
  border-radius:2px; margin-bottom:34px;
}
.os-intro h1{
  font-size:clamp(34px,6vw,72px); font-weight:200; color:#fff;
  line-height:1.2; letter-spacing:.03em; margin:0 0 26px;
}
.os-intro h1 strong{ font-weight:400; color:var(--red); }
.os-intro p{
  color:rgba(255,255,255,.55); font-size:17px; font-weight:300;
  max-width:560px; margin:0 0 44px; line-height:1.9;
}
.os-scroll{
  font-size:11px; letter-spacing:.28em; text-transform:uppercase;
  color:rgba(255,255,255,.34);
  animation:osNudge 2.4s var(--ease) infinite;
}
@keyframes osNudge{ 0%,100%{ transform:translateY(0); opacity:.4 } 50%{ transform:translateY(7px); opacity:1 } }

.os-outro{
  background:var(--ink); color:#fff; text-align:center;
  padding:120px var(--gut); position:relative; z-index:2;
}

/* 通用滚动揭示（内页用） */
.rv{ opacity:0; transform:translateY(20px); transition:opacity .7s var(--ease), transform .7s var(--ease); }
.rv.on{ opacity:1; transform:none; }

/* ============================================================
   内容区块 · 产品优势 / 应用案例 / 研究院 / 关于 / 背书
   这些类原先靠首页内联样式，新系统里统一用细边框 + 疏排重写：
   不用卡片阴影，用 1px 分隔线；不用图标色块，用序号与强调色点睛。
   ============================================================ */
.section{ padding:120px 0; position:relative; }
.features,.cases,.research,.about{ border-top:1px solid var(--line); }

/* ---- 产品优势：三列，序号 + 细线分隔 ---- */
.features-grid{
  display:grid; grid-template-columns:repeat(3,1fr);
  gap:1px; background:var(--line);
  border:1px solid var(--line); margin-top:52px;
}
.feature-item{
  background:var(--paper); padding:38px 34px 42px;
  transition:background var(--dur-fast) var(--ease);
}
.feature-item:hover{ background:#fff; }
.feature-item h4{
  margin:0 0 14px; font-size:17px; font-weight:500;
  color:var(--g900); letter-spacing:.02em;
  display:flex; align-items:baseline; gap:11px;
}
.feature-item h4::before{
  content:counter(fi,decimal-leading-zero);
  counter-increment:fi;
  font-size:11px; font-weight:400; color:var(--red);
  letter-spacing:.12em; font-variant-numeric:tabular-nums;
}
.features-grid{ counter-reset:fi; }
.feature-item p{
  margin:0; font-size:14.5px; line-height:1.85;
  color:var(--g600); font-weight:300;
}

/* ---- 应用案例：卡片，悬停时强调色上线 ---- */
.cases-grid{
  display:grid; grid-template-columns:repeat(3,1fr);
  gap:20px; margin-top:52px;
}
.case-card{
  position:relative; background:#fff;
  border:1px solid var(--line); padding:30px 28px 28px;
  transition:border-color var(--dur-fast) var(--ease),
             transform var(--dur-fast) var(--ease);
}
.case-card::after{
  content:""; position:absolute; left:0; right:0; top:-1px; height:1px;
  background:var(--red); transform:scaleX(0); transform-origin:left;
  transition:transform .5s var(--ease);
}
.case-card:hover{ transform:translateY(-3px); }
.case-card:hover::after{ transform:scaleX(1); }
.case-icon-wrap{ color:var(--red); margin-bottom:18px; }
.case-icon-wrap svg{ display:block; }
.case-body h4{
  margin:0 0 12px; font-size:16px; font-weight:500;
  color:var(--g900); letter-spacing:.02em;
}
.case-body p{
  margin:0 0 18px; font-size:14px; line-height:1.82;
  color:var(--g600); font-weight:300;
}
.case-tags{ display:flex; flex-wrap:wrap; gap:7px; }
.case-tag{
  font-size:11.5px; color:var(--metal-700);
  border:1px solid var(--line); padding:3px 9px; border-radius:2px;
  letter-spacing:.02em;
}

/* ---- 研究院：四列，纯文字 + 序号 ---- */
.research-grid{
  display:grid; grid-template-columns:repeat(4,1fr);
  gap:32px; margin-top:52px; counter-reset:ri;
}
.research-icon{ color:var(--red); margin-bottom:16px; }
.research-icon svg{ display:block; }
.research-grid h4,.research-item h4{
  margin:0 0 10px; font-size:16px; font-weight:500;
  color:var(--g900); letter-spacing:.02em;
}
.research-grid p,.research-item p{
  margin:0; font-size:14px; line-height:1.82;
  color:var(--g600); font-weight:300;
}
.research-cta{ margin-top:44px; }

/* ---- 关于：左文右数 ---- */
.about-grid{
  display:grid; grid-template-columns:1.15fr .85fr;
  gap:72px; align-items:start; margin-top:48px;
}
.about-text p{
  margin:0 0 20px; font-size:15.5px; line-height:1.95;
  color:var(--g600); font-weight:300;
}
.about-stats{
  display:grid; grid-template-columns:1fr 1fr;
  gap:1px; background:var(--line); border:1px solid var(--line);
}
.stat-item{ background:var(--paper); padding:26px 22px; }
.stat-number{
  font-size:30px; font-weight:200; color:var(--g900);
  letter-spacing:.02em; line-height:1.2; margin-bottom:6px;
  font-variant-numeric:tabular-nums;
}
.stat-number:first-child{ color:var(--red); }
.stat-label{
  font-size:12.5px; color:var(--metal-500);
  letter-spacing:.04em; line-height:1.6;
}

/* ---- 背书条：深色，四列 ---- */
.trust-strip{ background:var(--ink); color:#fff; padding:84px 0; }
.trust-grid{
  display:grid; grid-template-columns:repeat(4,1fr);
  max-width:var(--col); margin:0 auto; padding:0 var(--gut); gap:36px;
}
.trust-item{ border-left:1px solid var(--line-dark); padding-left:22px; }
.trust-num{
  font-size:16px; font-weight:400; color:#fff;
  letter-spacing:.02em; margin-bottom:8px;
}
.trust-label{
  font-size:13px; line-height:1.75; color:rgba(255,255,255,.42);
  font-weight:300;
}

/* ---------------- RESPONSIVE ---------------- */
@media (max-width:1000px){
  .ft-grid{ grid-template-columns:1fr 1fr; gap:36px; }
  .features-grid{ grid-template-columns:1fr 1fr; }
  .cases-grid{ grid-template-columns:1fr 1fr; }
  .research-grid{ grid-template-columns:1fr 1fr; gap:28px; }
  .trust-grid{ grid-template-columns:1fr 1fr; gap:28px; }
  .about-grid{ grid-template-columns:1fr; gap:44px; }
}
@media (max-width:640px){
  .features-grid,.cases-grid{ grid-template-columns:1fr; }
  .research-grid,.trust-grid,.about-stats{ grid-template-columns:1fr; }
  .feature-item{ padding:28px 24px 30px; }
  .trust-item{ border-left:0; border-top:1px solid var(--line-dark); padding:18px 0 0; }
  /* 链接里长公司名/URL 需要强制断词 */
  .official-link{ max-width:100%; overflow-wrap:anywhere; word-break:break-all; }
  .product-link,.match-card{ overflow-wrap:anywhere; }
  /* 防伪输入框在手机端改为纵向布局，否则按钮会被挤出视口 */
  .verify-input-group{ flex-direction:column; max-width:100%; }
  .verify-input-group .verify-btn{ width:100%; padding:14px; }
  .match-select-row{ flex-direction:column; }
  .match-select-row > *{ width:100%; }
}
@media (max-width:900px){
  :root{ --gut:22px; --col:100%; }
  .section{ padding:76px 0; }
  .sn-links{
    display:none; position:absolute; top:var(--nav-h); left:0; right:0;
    flex-direction:column; align-items:stretch; gap:0;
    background:rgba(247,247,248,.98); backdrop-filter:blur(20px);
    border-bottom:1px solid var(--line); padding:10px var(--gut) 18px;
  }
  .sn-links.show{ display:flex; }
  .sn-links a{ padding:12px 0; font-size:15px; }
  .sn-links a.sn-cta{ margin:10px 0 0; text-align:center; }
  .sn-links a.active::after{ display:none; }
  .sn-submenu{
    position:static; opacity:1; visibility:visible; transform:none;
    box-shadow:none; border:0; border-left:1px solid var(--line);
    margin:4px 0 4px 12px; padding:0; background:transparent; min-width:0;
  }
  .sn-dropdown:hover .sn-submenu{ display:block; }
  .sn-toggle{
    display:inline-flex; flex-direction:column; justify-content:center; gap:4px;
    width:34px; height:34px; background:none; border:0; cursor:pointer; padding:0;
  }
  .sn-toggle span{ display:block; height:1px; background:var(--g900); transition:all var(--dur-fast) var(--ease); }
  .sn-divider,.sn-divider-cta{ display:none; }

  .os-chapter{ min-height:78vh; }
  .os-chapter-inner{ max-width:none; }
  .os-rail{ right:12px; gap:10px; }
  .os-rail i{ height:18px; }
  .os-rail i.on::after{ display:none; }
  .os-viewport{ min-height:420px; }
  .ft-grid{ grid-template-columns:1fr; gap:30px; }
  .ft-bottom{ justify-content:center; text-align:center; }
}

/* 尊重系统减弱动效设置 */
@media (prefers-reduced-motion:reduce){
  *,*::before,*::after{
    animation-duration:.01ms !important; animation-iteration-count:1 !important;
    transition-duration:.01ms !important; scroll-behavior:auto !important;
  }
  .rv,.os-chapter-inner{ opacity:1 !important; transform:none !important; }
}