/* ===== 开元棋盘官方版中国站 · 共享样式 /assets/site.css ===== */

/* --- 1. Reset --- */
*,*::before,*::after{box-sizing:border-box}
html,body,h1,h2,h3,h4,h5,p,ul,ol,li,figure,blockquote,dl,dd{margin:0;padding:0}
ul,ol{list-style:none}
img,svg,video{display:block;max-width:100%}
button{font:inherit;color:inherit;background:none;border:0}
a{color:inherit;text-decoration:none}
[hidden]{display:none!important}

/* --- 2. 设计变量 --- */
:root{
  --ink-deep:#0B1F1A;
  --ink:#12362D;
  --celadon:#1E4D40;
  --moss:#2F6B58;
  --gold:#C9A227;
  --gold-light:#E3C56B;
  --cinnabar:#C0392B;
  --paper:#F5F2E9;
  --stone:#1A1A1A;
  --lime:#8A8F8A;
  --rail-w:264px;
  --maxw:1180px;
  --gutter:clamp(1.25rem,4vw,3rem);
  --line:rgba(201,162,39,.22);
  --line-soft:rgba(245,242,233,.12);
  --t-fast:.18s;
  --t-base:.38s;
  --t-slow:.7s;
  --ease:cubic-bezier(.22,.61,.36,1);
  --font-serif:'Noto Serif SC','Source Han Serif SC','Songti SC',Songti,STSong,serif;
  --font-sans:'Inter','Noto Sans SC','PingFang SC','Hiragino Sans GB','Microsoft YaHei',sans-serif;
}

/* --- 3. 中文排版与页面底 --- */
html{
  -webkit-text-size-adjust:100%;
  scroll-behavior:smooth;
  scroll-padding-top:84px;
}
body{
  font-family:var(--font-sans);
  font-size:1rem;
  line-height:1.75;
  font-weight:400;
  color:var(--paper);
  background-color:var(--ink-deep);
  background-image:
    repeating-linear-gradient(90deg,rgba(245,242,233,.028) 0 1px,transparent 1px 78px),
    repeating-linear-gradient(180deg,rgba(245,242,233,.028) 0 1px,transparent 1px 78px),
    radial-gradient(120% 70% at 84% -12%,rgba(30,77,64,.55),transparent 62%),
    radial-gradient(90% 60% at -10% 100%,rgba(201,162,39,.09),transparent 60%);
  background-attachment:fixed;
  padding-top:64px;
  min-height:100vh;
  -webkit-font-smoothing:antialiased;
}
h1,h2,h3,h4{font-family:var(--font-serif);font-weight:600;line-height:1.28;letter-spacing:.01em}
h1{font-size:clamp(2rem,4.6vw,3.4rem)}
h2{font-size:clamp(1.5rem,2.8vw,2.1rem)}
h3{font-size:clamp(1.125rem,1.8vw,1.35rem)}
p{text-wrap:pretty}
strong{color:var(--gold-light);font-weight:600}

:where(a,button,input,summary,[tabindex]):focus-visible{
  outline:2px solid var(--gold-light);
  outline-offset:3px;
}

/* --- 4. 布局骨架 --- */
.wrap{
  width:100%;
  max-width:var(--maxw);
  margin-inline:auto;
  padding-inline:var(--gutter);
}
.section{
  position:relative;
  padding-block:clamp(48px,8vw,96px);
}
.section--ink{background:linear-gradient(180deg,rgba(18,54,45,.85),rgba(11,31,26,.95))}
.section--paper{background:var(--paper);color:rgba(26,26,26,.86)}
.section--paper .display-title,
.section--paper h2,
.section--paper h3{color:var(--ink-deep)}
.section--paper .lede{color:rgba(26,26,26,.72)}
.section--paper .note,
.section--paper .media-caption{color:rgba(26,26,26,.55)}
.section--paper .eyebrow{color:#8a6d10}
.section--paper .index-list{border-top-color:rgba(11,31,26,.16)}
.section--paper .index-list>li{border-bottom-color:rgba(11,31,26,.16)}
.section--paper .index-val{color:rgba(26,26,26,.78)}
.section--paper .index-key{color:#8a6d10}
.section--paper .rule{background:linear-gradient(90deg,rgba(11,31,26,.35),rgba(11,31,26,0))}
.section--paper .btn--ghost{color:var(--ink-deep);border-color:rgba(11,31,26,.32)}
.section--paper .btn--ghost:hover{border-color:var(--gold);color:#8a6d10}

.section-head{
  display:flex;
  flex-direction:column;
  gap:14px;
  margin-bottom:clamp(24px,4vw,40px);
  max-width:70ch;
}
.eyebrow{
  display:inline-flex;
  align-items:center;
  gap:12px;
  font-size:.75rem;
  letter-spacing:.32em;
  text-transform:uppercase;
  color:var(--gold);
}
.eyebrow::before{content:"";display:block;width:26px;height:1px;background:currentColor}
.display-title{
  font-family:var(--font-serif);
  font-size:clamp(2.4rem,6vw,4.6rem);
  line-height:1.1;
  letter-spacing:.01em;
  margin:0;
}
.lede{
  font-size:clamp(1rem,1.5vw,1.15rem);
  line-height:1.85;
  color:rgba(245,242,233,.78);
  max-width:56ch;
}
.prose{
  max-width:68ch;
  font-size:1rem;
  line-height:1.85;
  color:rgba(245,242,233,.84);
}
.prose p{margin-bottom:1.05em}
.prose h2,.prose h3{margin:1.6em 0 .6em;color:var(--paper)}
.prose ul,.prose ol{margin:0 0 1.05em 1.1em;list-style:disc}
.prose li{margin-bottom:.4em}
.note{font-size:.8125rem;line-height:1.7;color:var(--lime)}
.rule{height:1px;border:0;margin:0;background:linear-gradient(90deg,rgba(201,162,39,.55),rgba(201,162,39,0))}

/* --- 5. 面包屑 --- */
.breadcrumb{font-size:.8125rem;color:var(--lime);padding-block:18px}
.breadcrumb-list{display:flex;flex-wrap:wrap;align-items:center;gap:8px}
.breadcrumb-list li+li::before{content:"/";margin-right:8px;color:rgba(201,162,39,.6)}
.breadcrumb-list a{color:rgba(245,242,233,.7);transition:color var(--t-fast)}
.breadcrumb-list a:hover{color:var(--gold-light)}
.breadcrumb-list [aria-current="page"]{color:var(--gold)}

/* --- 6. 按钮 --- */
.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:10px;
  padding:12px 22px;
  font-family:var(--font-sans);
  font-size:.875rem;
  letter-spacing:.16em;
  border:1px solid transparent;
  cursor:pointer;
  transition:background var(--t-fast),color var(--t-fast),border-color var(--t-fast),transform var(--t-fast);
}
.btn--gold{background:var(--gold);color:#14231e;border-color:var(--gold)}
.btn--gold:hover{background:var(--gold-light);border-color:var(--gold-light);transform:translateY(-1px)}
.btn--ghost{background:transparent;color:var(--paper);border-color:rgba(245,242,233,.34)}
.btn--ghost:hover{border-color:var(--gold);color:var(--gold-light)}
.btn--line{background:transparent;color:var(--gold);border-color:rgba(201,162,39,.5)}
.btn--line:hover{background:rgba(201,162,39,.12)}

/* --- 7. 标签与筛选 --- */
.tag-row{display:flex;flex-wrap:wrap;gap:8px}
.tag{
  display:inline-flex;
  align-items:center;
  gap:6px;
  padding:5px 12px;
  font-family:var(--font-sans);
  font-size:.75rem;
  letter-spacing:.14em;
  line-height:1.6;
  background:rgba(30,77,64,.35);
  color:rgba(245,242,233,.85);
  border:1px solid rgba(245,242,233,.22);
  cursor:pointer;
  transition:background var(--t-fast),color var(--t-fast),border-color var(--t-fast);
}
.tag--gold{background:rgba(201,162,39,.12);border-color:rgba(201,162,39,.55);color:var(--gold-light)}
.tag--red{background:rgba(192,57,43,.14);border-color:rgba(192,57,43,.62);color:#e5847a}
.tag--outline{background:transparent}
.tag[aria-pressed="true"]{background:var(--gold);color:#14231e;border-color:var(--gold)}
.tag:hover{border-color:var(--gold)}

/* --- 8. 资料卡与索引 --- */
.card-grid{
  display:grid;
  gap:16px;
  grid-template-columns:repeat(auto-fit,minmax(240px,1fr));
}
.archive-card{
  position:relative;
  padding:20px 20px 22px;
  background:linear-gradient(180deg,rgba(30,77,64,.5),rgba(18,54,45,.88));
  border:1px solid rgba(201,162,39,.16);
  transition:border-color var(--t-fast),transform var(--t-base) var(--ease),box-shadow var(--t-base);
}
.archive-card::before{
  content:"";
  position:absolute;
  inset:0 0 auto 0;
  height:2px;
  background:linear-gradient(90deg,var(--gold),rgba(201,162,39,0));
  opacity:.55;
}
.archive-card:hover{
  border-color:var(--cinnabar);
  transform:translateY(-3px);
  box-shadow:0 18px 34px -26px rgba(0,0,0,.9);
}
.archive-card__head{
  display:flex;
  align-items:baseline;
  justify-content:space-between;
  gap:12px;
  margin-bottom:10px;
}
.archive-card__title{font-family:var(--font-serif);font-size:1.125rem;color:var(--paper)}
.archive-card__meta{font-size:.8125rem;letter-spacing:.1em;color:var(--lime)}
.index-list{border-top:1px solid var(--line-soft)}
.index-list>li{
  display:grid;
  grid-template-columns:minmax(84px,140px) 1fr;
  gap:12px;
  padding:14px 4px;
  border-bottom:1px solid var(--line-soft);
}
.index-row{
  display:grid;
  grid-template-columns:minmax(84px,140px) 1fr;
  gap:12px;
  padding:14px 4px;
  border-bottom:1px solid var(--line-soft);
}
.index-key{font-size:.8125rem;letter-spacing:.16em;color:var(--gold);font-variant-numeric:tabular-nums}
.index-val{font-size:.9375rem;color:rgba(245,242,233,.82)}

/* --- 9. 图片容器与装饰 --- */
.media-frame{
  position:relative;
  display:block;
  overflow:hidden;
  aspect-ratio:16/10;
  border:1px solid rgba(201,162,39,.24);
  background-color:var(--ink);
  background-image:
    repeating-conic-gradient(from 0deg at 50% 50%,rgba(245,242,233,.055) 0 25%,transparent 0 50%),
    linear-gradient(140deg,var(--ink),var(--celadon));
  background-size:40px 40px,100% 100%;
}
.media-frame img{width:100%;height:100%;object-fit:cover}
.media-frame--wide{aspect-ratio:21/9}
.media-frame--tall{aspect-ratio:3/4}
.media-frame--square{aspect-ratio:1/1}
.media-grid{display:grid;gap:14px;grid-template-columns:repeat(auto-fit,minmax(200px,1fr))}
.media-caption{margin-top:10px;font-size:.8125rem;color:var(--lime)}
.board-veil{
  position:absolute;
  inset:0;
  pointer-events:none;
  opacity:.45;
  background-image:repeating-conic-gradient(from 0deg at 50% 50%,rgba(245,242,233,.05) 0 25%,transparent 0 50%);
  background-size:52px 52px;
}

/* --- 10. 滚动显现 --- */
[data-reveal]{
  opacity:0;
  transform:translateY(16px);
  transition:opacity var(--t-slow) var(--ease),transform var(--t-slow) var(--ease);
  transition-delay:var(--reveal-delay,0ms);
}
[data-reveal].is-revealed{opacity:1;transform:none}
html:not(.has-js) [data-reveal]{opacity:1;transform:none}

/* --- 11. 页头：移动优先 --- */
.skip-link{
  position:fixed;
  left:12px;
  top:-80px;
  z-index:120;
  padding:10px 16px;
  background:var(--gold);
  color:var(--ink-deep);
  font-size:.8125rem;
  letter-spacing:.12em;
  transition:top var(--t-fast) var(--ease);
}
.skip-link:focus{top:10px}

.site-header{
  position:fixed;
  top:0;
  left:0;
  right:0;
  height:64px;
  display:flex;
  align-items:center;
  gap:12px;
  padding:0 16px;
  background:var(--ink-deep);
  border-bottom:1px solid rgba(201,162,39,.24);
  z-index:90;
}
.site-header::after{
  content:"";
  position:absolute;
  left:0;
  right:0;
  bottom:-1px;
  height:1px;
  background:linear-gradient(90deg,rgba(201,162,39,.6),rgba(201,162,39,0));
}

.brand{display:flex;align-items:center;gap:10px;min-width:0}
.brand-mark{
  flex:0 0 34px;
  width:34px;
  height:34px;
  background-color:var(--ink-deep);
  background-image:conic-gradient(var(--gold) 0 25%,transparent 0 50%,var(--gold) 0 75%,transparent 0);
  background-size:17px 17px;
  border:1px solid rgba(201,162,39,.55);
}
.brand-text{display:flex;flex-direction:column;min-width:0;line-height:1.2}
.brand-name{font-family:var(--font-serif);font-size:1rem;letter-spacing:.12em;color:var(--paper)}
.brand-tag{font-size:.625rem;letter-spacing:.32em;color:var(--gold)}

.nav-toggle{
  margin-left:auto;
  display:inline-flex;
  align-items:center;
  gap:9px;
  padding:8px 12px;
  font-size:.75rem;
  letter-spacing:.22em;
  color:var(--gold-light);
  border:1px solid rgba(201,162,39,.45);
  cursor:pointer;
  transition:background var(--t-fast),color var(--t-fast),border-color var(--t-fast);
}
.nav-toggle:hover{background:rgba(30,77,64,.6);border-color:var(--gold);color:var(--paper)}
.nav-toggle[aria-expanded="true"]{background:var(--gold);border-color:var(--gold);color:var(--ink-deep)}
.nav-toggle-bars{position:relative;display:block;width:14px;height:2px;background:currentColor;transition:background var(--t-fast)}
.nav-toggle-bars::before,
.nav-toggle-bars::after{
  content:"";
  position:absolute;
  left:0;
  width:14px;
  height:2px;
  background:currentColor;
  transition:transform var(--t-base) var(--ease);
}
.nav-toggle-bars::before{top:-5px}
.nav-toggle-bars::after{top:5px}
.site-header[data-open="true"] .nav-toggle-bars{background:transparent}
.site-header[data-open="true"] .nav-toggle-bars::before{transform:translateY(5px) rotate(45deg)}
.site-header[data-open="true"] .nav-toggle-bars::after{transform:translateY(-5px) rotate(-45deg)}
.nav-toggle-label{font-family:var(--font-sans)}

.site-nav{
  position:fixed;
  top:64px;
  left:0;
  right:0;
  max-height:calc(100vh - 64px);
  overflow-y:auto;
  padding:10px 0 22px;
  background-color:#0d241e;
  background-image:
    repeating-linear-gradient(90deg,rgba(245,242,233,.04) 0 1px,transparent 1px 40px),
    repeating-linear-gradient(180deg,rgba(245,242,233,.04) 0 1px,transparent 1px 40px);
  border-bottom:1px solid rgba(201,162,39,.3);
  opacity:0;
  visibility:hidden;
  pointer-events:none;
  transform:translateY(-14px);
  transition:opacity var(--t-base) var(--ease),transform var(--t-base) var(--ease),visibility var(--t-base);
  z-index:88;
}
.site-header[data-open="true"] .site-nav,
.site-nav[data-open="true"]{
  opacity:1;
  visibility:visible;
  pointer-events:auto;
  transform:translateY(0);
}

.nav-index{display:flex;flex-direction:column}
.nav-item{border-top:1px solid rgba(245,242,233,.09)}
.nav-item:last-child{border-bottom:1px solid rgba(245,242,233,.09)}
.nav-link{
  position:relative;
  display:flex;
  align-items:baseline;
  gap:14px;
  padding:15px 22px;
  font-size:1rem;
  letter-spacing:.05em;
  color:rgba(245,242,233,.74);
  transition:color var(--t-fast),background var(--t-fast);
}
.nav-link::before{
  content:"";
  position:absolute;
  left:0;
  top:0;
  bottom:0;
  width:2px;
  background:var(--gold);
  transform:scaleY(0);
  transform-origin:top;
  transition:transform var(--t-base) var(--ease);
}
.nav-link:hover{color:var(--gold-light);background:rgba(47,107,88,.3)}
.nav-link:hover::before{transform:scaleY(1)}
.nav-link[aria-current="page"]{color:var(--gold);background:rgba(30,77,64,.55)}
.nav-link[aria-current="page"]::before{transform:scaleY(1)}
.nav-num{
  flex:0 0 auto;
  font-size:.6875rem;
  letter-spacing:.16em;
  color:rgba(201,162,39,.7);
  font-variant-numeric:tabular-nums;
}
.nav-link[aria-current="page"] .nav-num{color:var(--gold)}
.nav-label{font-family:var(--font-sans)}
.nav-note{
  padding:18px 22px 0;
  font-size:.75rem;
  letter-spacing:.2em;
  color:var(--lime);
}
.rail-progress{display:none}

/* --- 12. 页脚 --- */
.site-footer{
  position:relative;
  padding:clamp(38px,6vw,68px) var(--gutter) 26px;
  background:linear-gradient(180deg,#0B1F1A,#07130f);
  border-top:1px solid rgba(201,162,39,.26);
  color:rgba(245,242,233,.78);
}
.site-footer::before{
  content:"";
  position:absolute;
  inset:0 0 auto 0;
  height:120px;
  pointer-events:none;
  background-image:repeating-linear-gradient(90deg,rgba(245,242,233,.03) 0 1px,transparent 1px 44px);
  opacity:.8;
}
.footer-grid{
  position:relative;
  display:grid;
  grid-template-columns:1fr;
  gap:32px;
  max-width:var(--maxw);
  margin-inline:auto;
}
.footer-mark{
  font-family:var(--font-serif);
  font-size:1.25rem;
  letter-spacing:.12em;
  color:var(--gold-light);
  margin-bottom:8px;
}
.footer-line{
  font-size:.75rem;
  letter-spacing:.3em;
  color:var(--lime);
  margin-bottom:14px;
}
.footer-note{
  font-size:.875rem;
  line-height:1.8;
  color:rgba(245,242,233,.66);
  max-width:34ch;
  margin-bottom:18px;
}
.footer-cta{margin-top:2px}
.footer-title{
  font-family:var(--font-sans);
  font-size:.75rem;
  font-weight:600;
  letter-spacing:.3em;
  color:var(--gold);
  margin-bottom:16px;
}
.footer-list{display:flex;flex-direction:column;gap:10px;font-size:.875rem}
.footer-list a{
  display:inline-block;
  color:rgba(245,242,233,.78);
  transition:color var(--t-fast);
}
.footer-list a::after{
  content:"";
  display:block;
  width:0;
  height:1px;
  background:var(--gold);
  transition:width var(--t-base) var(--ease);
}
.footer-list a:hover{color:var(--gold-light)}
.footer-list a:hover::after{width:100%}
.footer-list--meta{gap:12px}
.footer-list--meta li{display:flex;gap:12px;align-items:baseline}
.footer-meta-key{
  flex:0 0 42px;
  font-size:.6875rem;
  letter-spacing:.2em;
  color:var(--lime);
}
.footer-meta-val{font-size:.875rem;line-height:1.7;color:rgba(245,242,233,.82);word-break:break-word}
.footer-base{
  position:relative;
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  justify-content:space-between;
  gap:12px 24px;
  max-width:var(--maxw);
  margin:34px auto 0;
  padding-top:18px;
  border-top:1px solid rgba(245,242,233,.1);
  font-size:.75rem;
  letter-spacing:.06em;
  color:var(--lime);
}
.footer-legal{display:flex;flex-wrap:wrap;gap:18px}
.footer-legal a{color:rgba(245,242,233,.7);transition:color var(--t-fast)}
.footer-legal a:hover{color:var(--gold-light)}

/* --- 13. 平板 --- */
@media (min-width:720px){
  .footer-grid{grid-template-columns:1.25fr .85fr 1fr;gap:34px}
  .index-list>li,.index-row{grid-template-columns:minmax(110px,170px) 1fr}
}

/* --- 14. 桌面：侧边轨道 --- */
@media (min-width:1040px){
  html{scroll-padding-top:32px}
  body{padding-top:0;padding-left:var(--rail-w)}

  .site-header{
    top:0;
    left:0;
    bottom:0;
    right:auto;
    width:var(--rail-w);
    height:auto;
    flex-direction:column;
    align-items:stretch;
    gap:0;
    padding:30px 0 0;
    border-bottom:0;
    border-right:1px solid rgba(201,162,39,.18);
    background-image:
      repeating-linear-gradient(180deg,rgba(245,242,233,.035) 0 1px,transparent 1px 56px),
      linear-gradient(180deg,#0B1F1A,#091815);
  }
  .site-header::after{display:none}

  .brand{align-items:flex-start;gap:14px;padding:0 22px 26px}
  .brand-mark{flex-basis:42px;width:42px;height:42px;background-size:21px 21px}
  .brand-name{font-size:1.125rem;letter-spacing:.16em}
  .brand-tag{font-size:.6875rem;letter-spacing:.34em;margin-top:2px}

  .nav-toggle{display:none}

  .site-nav{
    position:static;
    flex:1 1 auto;
    max-height:none;
    overflow-y:auto;
    padding:0;
    background:none;
    border:0;
    opacity:1;
    visibility:visible;
    pointer-events:auto;
    transform:none;
    transition:none;
    display:flex;
    flex-direction:column;
  }
  .nav-item{border-top-color:rgba(245,242,233,.08)}
  .nav-link{padding:13px 22px;font-size:.9375rem}
  .nav-note{padding:20px 22px 0;margin-top:auto}

  .rail-progress{
    display:block;
    height:2px;
    margin:22px 22px 26px;
    background-color:rgba(245,242,233,.12);
    background-image:linear-gradient(90deg,var(--gold),var(--gold-light));
    background-repeat:no-repeat;
    background-size:0 100%;
    transition:background-size .12s linear;
  }

  .media-grid{grid-template-columns:repeat(auto-fit,minmax(240px,1fr))}
}

/* --- 15. 无障碍动效降级 --- */
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{
    transition-duration:.001ms!important;
    animation-duration:.001ms!important;
    animation-iteration-count:1!important;
  }
  [data-reveal]{opacity:1;transform:none}
}