/* ============================================================
   开元棋盘主站 · 共享样式 /assets/site.css
   框架式页头 + 左缘索引带 + 纵向叙事长卷基础组件
   ============================================================ */

:root{
  /* 品牌色彩 */
  --ink-deep:#0D2A23;
  --ink-mid:#17483B;
  --paper-yellow:#E4D3A6;
  --paper:#F6F1E3;
  --wood:#8A5A2B;
  --wood-light:#C79A5B;
  --neon:#1FD8C0;
  --indigo:#3B2E6E;
  --wine:#7E2233;
  --note:#E9A13B;
  --ink-text:#14201C;
  --muted:#6C7C74;

  /* 结构尺寸 */
  --rail-w:264px;
  --top-h:68px;
  --gutter:clamp(18px,3.6vw,56px);
  --wrap:1180px;

  /* 字体 */
  --font-head:"Noto Serif SC","Source Han Serif SC","Songti SC","STSong","SimSun",serif;
  --font-body:"Noto Sans SC","Source Han Sans SC","PingFang SC","Microsoft YaHei","Helvetica Neue",sans-serif;
  --font-mono:"IBM Plex Mono","JetBrains Mono",ui-monospace,SFMono-Regular,Consolas,"Courier New",monospace;
}

/* ---------- reset ---------- */
*,
*::before,
*::after{box-sizing:border-box;margin:0;padding:0}

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

body{
  font-family:var(--font-body);
  font-size:17px;
  line-height:1.85;
  font-weight:400;
  color:var(--ink-text);
  background-color:var(--paper);
  min-height:100vh;
  padding-top:var(--top-h);
  padding-left:var(--rail-w);
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
  overflow-x:hidden;
}

img,picture,svg,video{display:block;max-width:100%}
ul,ol{list-style:none}
button{font:inherit;color:inherit;background:none;border:0}
input{font:inherit}
a{color:inherit}
table{border-collapse:collapse;width:100%}

:focus-visible{
  outline:2px solid var(--neon);
  outline-offset:3px;
}

/* ---------- 中文排版 ---------- */
h1,h2,h3,h4,h5{
  font-family:var(--font-head);
  font-weight:800;
  line-height:1.28;
  letter-spacing:-0.01em;
  color:var(--ink-deep);
  text-wrap:balance;
}
h1{font-size:clamp(30px,4.6vw,56px);font-weight:900}
h2{font-size:clamp(25px,3vw,40px)}
h3{font-size:clamp(20px,2vw,28px)}
h4{font-size:20px}
p{text-wrap:pretty}

code,kbd,samp,.mono{font-family:var(--font-mono);font-size:0.94em}

/* ---------- 跳转链接 ---------- */
.skip-link{
  position:fixed;
  top:-200px;
  left:12px;
  z-index:999;
  padding:12px 22px;
  background:var(--neon);
  color:var(--ink-deep);
  font-family:var(--font-mono);
  font-size:14px;
  font-weight:600;
  letter-spacing:0.06em;
  text-decoration:none;
  clip-path:polygon(0 0, calc(100% - 10px) 0, 100% 10px, 100% 100%, 10px 100%, 0 calc(100% - 10px));
}
.skip-link:focus{
  top:12px;
}

/* ============================================================
   页头：深墨绿色带环绕视口上缘
   ============================================================ */
.site-header{
  position:fixed;
  top:0;
  left:0;
  right:0;
  height:var(--top-h);
  z-index:80;
  background-color:var(--ink-deep);
  border-bottom:1px solid rgba(138,90,43,0.55);
}
.site-header::after{
  content:"";
  position:absolute;
  top:0;
  left:0;
  right:0;
  height:2px;
  background:linear-gradient(90deg,var(--neon) 0%,rgba(31,216,192,0.25) 38%,rgba(233,161,59,0.55) 100%);
  opacity:0.75;
  pointer-events:none;
}

.header-bar{
  position:relative;
  z-index:2;
  height:100%;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:14px;
  padding:0 clamp(14px,2.4vw,28px);
}

/* 品牌 */
.brand-mark{
  display:inline-flex;
  align-items:center;
  gap:12px;
  min-width:0;
  text-decoration:none;
  color:var(--paper);
}
.brand-seal{
  flex:0 0 auto;
  width:38px;
  height:38px;
  display:grid;
  place-items:center;
  background:var(--neon);
  color:var(--ink-deep);
  font-family:var(--font-head);
  font-size:20px;
  font-weight:900;
  line-height:1;
  clip-path:polygon(0 0, 74% 0, 100% 26%, 100% 100%, 26% 100%, 0 74%);
}
.brand-text{
  display:flex;
  flex-direction:column;
  gap:1px;
  min-width:0;
}
.brand-name{
  font-family:var(--font-head);
  font-size:17px;
  font-weight:800;
  line-height:1.2;
  letter-spacing:0.01em;
  color:#fff;
  white-space:nowrap;
}
.brand-sub{
  font-family:var(--font-mono);
  font-size:10.5px;
  line-height:1.3;
  letter-spacing:0.22em;
  color:rgba(228,211,166,0.62);
  white-space:nowrap;
}

/* 工具区 */
.header-tools{
  display:flex;
  align-items:center;
  gap:10px;
  margin-left:auto;
}
.header-hint{
  margin:0;
  padding-right:14px;
  border-right:1px dashed rgba(138,90,43,0.8);
  font-size:14px;
  line-height:1.4;
  color:rgba(228,211,166,0.62);
  white-space:nowrap;
}

.search-toggle,
.nav-toggle{
  display:inline-flex;
  align-items:center;
  gap:8px;
  padding:8px 14px;
  cursor:pointer;
  font-family:var(--font-mono);
  font-size:13px;
  font-weight:600;
  letter-spacing:0.08em;
  color:var(--paper-yellow);
  background:transparent;
  border:1px solid rgba(138,90,43,0.85);
  clip-path:polygon(0 0, calc(100% - 9px) 0, 100% 9px, 100% 100%, 9px 100%, 0 calc(100% - 9px));
  transition:background-color .2s ease,color .2s ease,border-color .2s ease;
  white-space:nowrap;
}
.search-toggle:hover,
.nav-toggle:hover{
  color:#fff;
  background-color:rgba(31,216,192,0.14);
  border-color:var(--neon);
}
.search-toggle[aria-expanded="true"]{
  background-color:var(--neon);
  border-color:var(--neon);
  color:var(--ink-deep);
}

.nav-toggle{display:none}
.nav-toggle-text{
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:0.14em;
}
.nav-toggle-bars{
  position:relative;
  display:block;
  width:18px;
  height:2px;
  background-color:currentColor;
}
.nav-toggle-bars::before,
.nav-toggle-bars::after{
  content:"";
  position:absolute;
  left:0;
  width:18px;
  height:2px;
  background-color:currentColor;
  transition:transform .22s ease,top .22s ease;
}
.nav-toggle-bars::before{top:-6px}
.nav-toggle-bars::after{top:6px}
.nav-toggle[aria-expanded="true"] .nav-toggle-bars{background-color:transparent}
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::before{top:0;transform:rotate(45deg)}
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::after{top:0;transform:rotate(-45deg)}

/* 检索面板 */
.search-panel{
  position:absolute;
  top:100%;
  left:0;
  right:0;
  z-index:6;
  display:flex;
  align-items:center;
  flex-wrap:wrap;
  gap:12px 16px;
  padding:16px var(--gutter) 18px;
  background-color:var(--ink-mid);
  border-bottom:1px solid rgba(138,90,43,0.7);
  box-shadow:0 20px 32px -24px rgba(0,0,0,0.85);
}
.search-panel[hidden]{display:none}
.search-label{
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:0.2em;
  color:rgba(228,211,166,0.7);
}
.search-input{
  flex:1 1 240px;
  min-width:0;
  padding:10px 14px;
  font-size:16px;
  color:var(--ink-text);
  background-color:var(--paper);
  border:1px solid rgba(31,216,192,0.42);
  border-radius:0;
}
.search-input::placeholder{color:rgba(108,124,116,0.9)}
.search-input:focus-visible{
  outline:2px solid var(--neon);
  outline-offset:2px;
}
.search-status{
  flex:1 1 100%;
  margin:0;
  font-size:14px;
  line-height:1.6;
  color:rgba(228,211,166,0.72);
}

/* 阅读进度 */
.progress-track{
  position:absolute;
  left:0;
  right:0;
  bottom:-1px;
  z-index:7;
  height:2px;
  background-color:rgba(228,211,166,0.14);
}
.progress-bar{
  display:block;
  width:0;
  height:100%;
  background:linear-gradient(90deg,var(--wood-light) 0%,var(--neon) 100%);
  transition:width .1s linear;
}

/* ============================================================
   左缘竖直索引带
   ============================================================ */
.site-nav{
  position:fixed;
  top:var(--top-h);
  left:0;
  bottom:0;
  z-index:70;
  width:var(--rail-w);
  display:flex;
  flex-direction:column;
  gap:16px;
  padding:24px 0 28px;
  overflow-y:auto;
  overflow-x:hidden;
  background-color:var(--ink-mid);
  background-image:repeating-linear-gradient(180deg,rgba(13,42,35,0.4) 0 1px,transparent 1px 7px);
  border-right:1px solid rgba(138,90,43,0.55);
}
.site-nav::before{
  content:"";
  display:block;
  flex:0 0 auto;
  width:54px;
  height:3px;
  margin:0 22px 4px;
  background-color:var(--neon);
  opacity:0.82;
}

.rail-head{
  display:flex;
  align-items:baseline;
  justify-content:space-between;
  gap:10px;
  padding:0 22px;
  margin:0;
  font-family:var(--font-mono);
  font-size:11.5px;
  letter-spacing:0.22em;
  color:rgba(228,211,166,0.72);
}
.rail-count{
  color:var(--neon);
  letter-spacing:0.08em;
}

.rail-list{
  display:flex;
  flex-direction:column;
  gap:2px;
  margin:0;
  padding:0;
}
.rail-item{display:block}

.rail-link{
  display:grid;
  grid-template-columns:32px 1fr;
  column-gap:8px;
  align-items:baseline;
  padding:13px 20px 13px 22px;
  font-size:16px;
  line-height:1.5;
  color:var(--paper-yellow);
  text-decoration:none;
  border-left:3px solid transparent;
  transition:background-color .18s ease,border-color .18s ease,color .18s ease;
}
.rail-link:hover{
  color:var(--paper);
  background-color:rgba(31,216,192,0.1);
  border-left-color:rgba(31,216,192,0.6);
}
.rail-link[aria-current="page"]{
  color:#fff;
  background-color:rgba(228,211,166,0.13);
  border-left-color:var(--neon);
}
.rail-link[aria-current="page"] .rail-num{color:var(--neon)}
.rail-link.is-current{color:var(--neon)}
.rail-num{
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:0.06em;
  color:rgba(228,211,166,0.48);
}
.rail-label{
  font-family:var(--font-head);
  font-weight:700;
  letter-spacing:-0.005em;
}

.rail-foot{
  margin:auto 0 0;
  padding:18px 22px 0;
  border-top:1px dashed rgba(138,90,43,0.7);
  font-size:14px;
  line-height:1.75;
  color:rgba(228,211,166,0.55);
}

/* ============================================================
   通用容器与栅格
   ============================================================ */
.wrap{
  width:100%;
  max-width:var(--wrap);
  margin-inline:auto;
  padding-inline:var(--gutter);
}

.prose{
  max-width:72ch;
  font-size:17px;
  line-height:1.85;
}
.prose > p{margin-bottom:1.05em}
.prose h3,
.prose h4{margin:1.9em 0 0.6em}
.prose ul,
.prose ol{
  list-style:disc;
  margin:0 0 1.05em;
  padding-left:1.4em;
}
.prose ol{list-style:decimal}
.prose li{margin-bottom:0.42em}
.prose strong{font-weight:600}
.prose a{
  color:var(--ink-mid);
  text-decoration:underline;
  text-decoration-style:dashed;
  text-decoration-thickness:1px;
  text-underline-offset:4px;
}
.prose a:hover{color:var(--neon);text-decoration-color:var(--neon)}

.grid{display:grid;gap:clamp(16px,2.4vw,28px)}
.grid--2{grid-template-columns:repeat(auto-fit,minmax(260px,1fr))}
.grid--3{grid-template-columns:repeat(auto-fit,minmax(216px,1fr))}
.grid--board{grid-template-columns:repeat(12,1fr)}

.grid--board > *{grid-column:span 12}
.grid--board > .col-3{grid-column:span 3}
.grid--board > .col-4{grid-column:span 4}
.grid--board > .col-5{grid-column:span 5}
.grid--board > .col-6{grid-column:span 6}
.grid--board > .col-7{grid-column:span 7}
.grid--board > .col-8{grid-column:span 8}
.grid--board > .col-9{grid-column:span 9}

/* ============================================================
   色带 / 章节头
   ============================================================ */
.band{
  position:relative;
  padding-block:clamp(46px,7vw,96px);
}
.band--paper{background-color:var(--paper);color:var(--ink-text)}
.band--yellow{background-color:var(--paper-yellow);color:var(--ink-text)}
.band--deep{background-color:var(--ink-deep);color:var(--paper-yellow)}
.band--dark{background-color:var(--ink-mid);color:var(--paper-yellow)}
.band--indigo{background-color:var(--indigo);color:var(--paper)}

.band--deep h1,.band--deep h2,.band--deep h3,.band--deep h4,
.band--dark h1,.band--dark h2,.band--dark h3,.band--dark h4,
.band--indigo h1,.band--indigo h2,.band--indigo h3,.band--indigo h4{color:#fff}

.band--cut{clip-path:polygon(0 0, 100% 0, 100% calc(100% - 34px), 0 100%)}
.band--cut-top{clip-path:polygon(0 34px, 100% 0, 100% 100%, 0 100%)}

.chapter-head{
  display:flex;
  flex-direction:column;
  gap:8px;
  padding-left:18px;
  margin-bottom:clamp(22px,3vw,38px);
  border-left:4px solid var(--wood);
}
.chapter-num{
  font-family:var(--font-mono);
  font-size:13px;
  letter-spacing:0.16em;
  color:var(--wood);
}
.chapter-title{margin:0}
.chapter-sub{
  margin:0;
  max-width:62ch;
  font-size:16px;
  color:var(--muted);
}
.band--deep .chapter-sub,
.band--dark .chapter-sub,
.band--indigo .chapter-sub{color:rgba(228,211,166,0.74)}
.band--deep .chapter-num,
.band--dark .chapter-num{color:var(--wood-light)}
.band--indigo .chapter-num{color:var(--neon)}

/* ============================================================
   基础组件
   ============================================================ */
.panel{
  padding:clamp(18px,2.4vw,28px);
  background-color:var(--paper);
  border:1px solid rgba(138,90,43,0.5);
  clip-path:polygon(0 0, calc(100% - 18px) 0, 100% 18px, 100% 100%, 18px 100%, 0 calc(100% - 18px));
}
.panel--deep{
  background-color:var(--ink-mid);
  color:var(--paper-yellow);
  border-color:rgba(31,216,192,0.28);
}
.panel--deep h2,.panel--deep h3,.panel--deep h4{color:#fff}

.tag{
  display:inline-block;
  padding:3px 10px;
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:0.1em;
  background-color:var(--note);
  color:var(--ink-deep);
  clip-path:polygon(0 0, calc(100% - 7px) 0, 100% 7px, 100% 100%, 7px 100%, 0 calc(100% - 7px));
}
.tag--neon{background-color:var(--neon);color:var(--ink-deep)}
.tag--wine{background-color:var(--wine);color:var(--paper)}
.tag--indigo{background-color:var(--indigo);color:var(--paper-yellow)}

.timeline{
  border-left:2px solid rgba(138,90,43,0.5);
  padding-left:0;
}
.timeline > li{
  position:relative;
  padding:0 0 26px 26px;
}
.timeline > li::before{
  content:"";
  position:absolute;
  left:-7px;
  top:9px;
  width:12px;
  height:12px;
  background-color:var(--note);
  clip-path:polygon(50% 0, 100% 50%, 50% 100%, 0 50%);
}

.tilt{transform:rotate(-1.6deg)}
.tilt--right{transform:rotate(1.8deg)}

/* 检索命中 */
.kw-hit{
  color:var(--neon);
  text-decoration:underline dashed;
  text-decoration-thickness:1px;
  text-underline-offset:4px;
}
.band--paper .kw-hit,
.band--yellow .kw-hit{
  color:var(--ink-mid);
  text-decoration-color:var(--wood);
}
.hit-mark{
  padding-left:14px;
  border-left:3px solid var(--wood);
}

/* 按钮 */
.btn{
  display:inline-flex;
  align-items:center;
  gap:8px;
  padding:12px 22px;
  cursor:pointer;
  font-family:var(--font-mono);
  font-size:14px;
  font-weight:600;
  letter-spacing:0.06em;
  text-decoration:none;
  border:1px solid transparent;
  clip-path:polygon(0 0, calc(100% - 12px) 0, 100% 12px, 100% 100%, 12px 100%, 0 calc(100% - 12px));
  transition:background-color .2s ease,color .2s ease,border-color .2s ease,transform .2s ease;
}
.btn--primary{background-color:var(--neon);color:var(--ink-deep)}
.btn--primary:hover{background-color:#4BE6D2;transform:translateY(-1px)}
.btn--ghost{border-color:rgba(199,154,91,0.8);color:var(--paper-yellow)}
.btn--ghost:hover{color:#fff;background-color:rgba(31,216,192,0.12);border-color:var(--neon)}
.btn--line{border-color:var(--wood);color:var(--ink-text)}
.btn--line:hover{background-color:var(--paper-yellow)}

/* 面包屑 */
.breadcrumb{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:8px;
  padding-top:22px;
  font-family:var(--font-mono);
  font-size:12.5px;
  letter-spacing:0.08em;
  color:var(--muted);
}
.breadcrumb a{
  color:inherit;
  text-decoration:none;
  border-bottom:1px dashed rgba(138,90,43,0.6);
}
.breadcrumb a:hover{color:var(--ink-mid);border-bottom-color:var(--neon)}
.breadcrumb-sep{color:var(--wood);opacity:0.6}

/* ============================================================
   图片容器（页面阶段放置图片占位）
   ============================================================ */
.figure{margin:0}
.figure-img{
  position:relative;
  overflow:hidden;
  aspect-ratio:4 / 3;
  background-color:var(--ink-mid);
  background-image:linear-gradient(135deg,var(--ink-mid) 0%,var(--ink-deep) 100%);
  border:1px solid rgba(138,90,43,0.5);
  clip-path:polygon(0 0, calc(100% - 22px) 0, 100% 22px, 100% 100%, 22px 100%, 0 calc(100% - 22px));
}
.figure-img[data-ratio="wide"]{aspect-ratio:16 / 9}
.figure-img[data-ratio="tall"]{aspect-ratio:3 / 4}
.figure-img[data-ratio="square"]{aspect-ratio:1 / 1}
.figure-img > img,
.figure-img > picture,
.figure-img > svg{
  width:100%;
  height:100%;
  object-fit:cover;
}
.figure-cap{
  margin-top:10px;
  padding-left:10px;
  border-left:2px solid var(--wood);
  font-size:14px;
  line-height:1.7;
  color:var(--muted);
}
.band--deep .figure-cap,
.band--dark .figure-cap,
.band--indigo .figure-cap{color:rgba(228,211,166,0.7)}

/* ============================================================
   入场显现
   ============================================================ */
[data-reveal]{opacity:1;transform:none}
html.has-js [data-reveal]{
  opacity:0;
  transform:translateY(16px);
  transition:opacity .4s ease,transform .4s ease;
}
html.has-js [data-reveal].is-visible{
  opacity:1;
  transform:none;
}

/* ============================================================
   页脚
   ============================================================ */
.site-footer{
  position:relative;
  padding:clamp(40px,6vw,72px) 0 0;
  background-color:var(--ink-deep);
  color:var(--paper-yellow);
  border-top:1px solid rgba(138,90,43,0.6);
}
.site-footer::after{
  content:"";
  position:absolute;
  left:0;
  right:0;
  bottom:0;
  height:6px;
  background-image:repeating-linear-gradient(90deg,var(--wood) 0 12px,transparent 12px 24px);
  opacity:0.32;
  pointer-events:none;
}

.footer-inner{
  display:grid;
  grid-template-columns:minmax(220px,1.3fr) repeat(3,minmax(128px,1fr));
  gap:clamp(24px,3.4vw,48px);
}

.footer-mark{
  margin:0 0 10px;
  font-family:var(--font-head);
  font-size:22px;
  font-weight:800;
  letter-spacing:-0.01em;
  color:#fff;
}
.footer-slogan{
  margin:0 0 12px;
  font-family:var(--font-head);
  font-size:16px;
  font-weight:700;
  line-height:1.7;
  color:var(--paper-yellow);
}
.footer-note{
  margin:0;
  font-size:14px;
  line-height:1.8;
  color:rgba(228,211,166,0.58);
}

.footer-col-title{
  margin:0 0 14px;
  padding-bottom:8px;
  border-bottom:1px dashed rgba(138,90,43,0.7);
  font-family:var(--font-mono);
  font-size:12px;
  font-weight:600;
  letter-spacing:0.2em;
  color:var(--neon);
}

.footer-list{
  display:flex;
  flex-direction:column;
  gap:9px;
}
.footer-link{
  font-size:15px;
  line-height:1.6;
  color:rgba(228,211,166,0.84);
  text-decoration:none;
  border-bottom:1px solid transparent;
  transition:color .18s ease,border-color .18s ease;
}
.footer-link:hover{
  color:#fff;
  border-bottom-color:var(--neon);
}

.footer-contact{
  grid-column:1 / -1;
  display:grid;
  grid-template-columns:repeat(auto-fit,minmax(228px,1fr));
  gap:18px 24px;
  padding-top:clamp(20px,2.6vw,30px);
  border-top:1px dashed rgba(138,90,43,0.7);
}
.footer-contact .footer-col-title{
  grid-column:1 / -1;
  margin-bottom:0;
}

.contact-item{
  display:flex;
  flex-direction:column;
  gap:4px;
  min-width:0;
}
.contact-key{
  font-family:var(--font-mono);
  font-size:11.5px;
  letter-spacing:0.18em;
  color:rgba(228,211,166,0.5);
}
.contact-val{
  font-size:15px;
  line-height:1.65;
  color:var(--paper);
  word-break:break-word;
}
.contact-row{
  display:flex;
  align-items:center;
  flex-wrap:wrap;
  gap:10px;
}

.copy-btn{
  padding:3px 10px;
  cursor:pointer;
  font-family:var(--font-mono);
  font-size:11.5px;
  letter-spacing:0.1em;
  color:var(--neon);
  background-color:transparent;
  border:1px solid rgba(31,216,192,0.5);
  clip-path:polygon(0 0, calc(100% - 7px) 0, 100% 7px, 100% 100%, 7px 100%, 0 calc(100% - 7px));
  transition:background-color .18s ease,color .18s ease,border-color .18s ease;
}
.copy-btn:hover{
  background-color:var(--neon);
  border-color:var(--neon);
  color:var(--ink-deep);
}

.footer-bottom{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:12px 22px;
  margin-top:clamp(30px,4vw,50px);
  padding-top:20px;
  padding-bottom:26px;
  border-top:1px solid rgba(138,90,43,0.45);
  font-size:13.5px;
  color:rgba(228,211,166,0.6);
}
.footer-filing{
  margin:0;
  font-family:var(--font-mono);
  letter-spacing:0.06em;
}
.footer-copy{margin:0}
.footer-legal{
  display:flex;
  flex-wrap:wrap;
  gap:16px;
  margin-left:auto;
}
.footer-legal .footer-link{font-size:13.5px}

/* ============================================================
   响应式
   ============================================================ */
@media (max-width:1024px){
  :root{--top-h:62px}

  body{padding-left:0}

  .nav-toggle{display:inline-flex}
  .header-hint{display:none}

  .brand-sub{display:none}

  .site-nav{
    width:min(320px,86vw);
    transform:translateX(-104%);
    transition:transform .28s ease;
    box-shadow:16px 0 40px -18px rgba(0,0,0,0.75);
  }
  .site-nav[data-open]{transform:translateX(0)}

  .footer-inner{grid-template-columns:repeat(2,minmax(0,1fr))}
  .footer-brand{grid-column:1 / -1}
}

@media (max-width:900px){
  .grid--board > [class^="col-"]{grid-column:span 12}
}

@media (max-width:640px){
  body{font-size:16px}

  .brand-name{font-size:15px}
  .brand-seal{width:34px;height:34px;font-size:18px}

  .search-toggle{padding:7px 11px;font-size:12px}
  .search-panel{padding:14px 18px 16px}

  .footer-inner{grid-template-columns:1fr}
  .footer-legal{margin-left:0}
  .footer-bottom{padding-bottom:30px}
}

/* ============================================================
   减弱动效
   ============================================================ */
@media (prefers-reduced-motion: reduce){
  html{scroll-behavior:auto}

  *,
  *::before,
  *::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
    transition-delay:0ms !important;
  }

  html.has-js [data-reveal]{
    opacity:1;
    transform:none;
  }
  .progress-bar{transition:none}
}