/* =========================================================
   币游平台 · 共享样式 /assets/site.css
   深海蓝侧轨 + 蓝图网格 + 玻璃层与实色层并置
   ========================================================= */

/* ---------- 1. Reset ---------- */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{margin:0;min-height:100vh;overflow-x:hidden;position:relative;
  background-color:var(--paper);color:var(--ink);
  font-family:var(--font-body);font-size:16px;line-height:1.85;font-weight:400}
img,svg,video,canvas{display:block;max-width:100%}
button,input,select,textarea{font:inherit;color:inherit}
button{background:none;border:0;padding:0;cursor:pointer}
ul,ol{margin:0;padding:0;list-style:none}
h1,h2,h3,h4,h5,p,figure,blockquote,dl,dd{margin:0}
a{color:inherit;text-decoration:none}
table{border-collapse:collapse;width:100%}
:focus-visible{outline:2px solid var(--gold);outline-offset:3px;border-radius:6px}

/* ---------- 2. Tokens ---------- */
:root{
  --sea-900:#0B2545;
  --sea-700:#123A63;
  --sea-500:#1E5C8F;
  --gold:#C9A227;
  --gold-soft:#E8C55A;
  --mint:#5FC7A9;
  --amber:#F2994A;
  --paper:#F5F7FA;
  --white:#FFFFFF;
  --ink:#16202B;
  --slate:#5A6B7C;
  --line:#A9C4DC;
  --line-soft:#DCE7F1;
  --on-dark:#E8EDF3;

  --font-display:"HarmonyOS Sans SC","Source Han Sans SC","Noto Sans SC","PingFang SC","Microsoft YaHei",system-ui,sans-serif;
  --font-body:"Source Han Sans SC","Noto Sans SC","PingFang SC","Microsoft YaHei",system-ui,sans-serif;
  --font-serif:"Songti SC","Source Han Serif SC","Noto Serif SC",SimSun,Georgia,serif;
  --font-mono:"JetBrains Mono","IBM Plex Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;

  --rail-w:236px;
  --rail-top-h:58px;
  --gap-1:8px;
  --gap-2:16px;
  --gap-3:24px;
  --gap-4:40px;
  --gap-5:64px;
  --radius-sm:10px;
  --radius:16px;
  --radius-lg:22px;
  --shadow-card:0 1px 0 rgba(11,37,69,.05),0 14px 30px -24px rgba(11,37,69,.42);
  --ease:cubic-bezier(.22,.61,.36,1);
}

/* ---------- 3. 蓝图底层网格 ---------- */
body::before{content:"";position:fixed;inset:0;z-index:0;pointer-events:none;
  background-image:repeating-linear-gradient(to bottom,rgba(169,196,220,.34) 0 1px,transparent 1px 96px)}
body::after{content:"";position:fixed;top:0;bottom:0;right:52px;width:1px;z-index:0;pointer-events:none;
  background:linear-gradient(180deg,transparent,rgba(169,196,220,.8) 10%,rgba(169,196,220,.8) 90%,transparent)}

/* ---------- 4. 排版 ---------- */
h1,h2,h3,h4{font-family:var(--font-display);line-height:1.28;letter-spacing:-.01em;color:var(--ink);font-weight:700}
h1{font-size:clamp(30px,4.2vw,44px)}
h2{font-size:clamp(22px,2.6vw,34px)}
h3{font-size:clamp(18px,2vw,26px);font-weight:600}
h4{font-size:20px;font-weight:600}
p{font-size:16px;line-height:1.85}
strong{font-weight:700;color:var(--sea-900)}
.t-display{font-family:var(--font-display);font-weight:700;font-size:clamp(30px,4.2vw,44px);line-height:1.25;letter-spacing:-.01em}
.t-h2{font-family:var(--font-display);font-weight:700;font-size:clamp(22px,2.6vw,34px);line-height:1.3}
.t-h3{font-family:var(--font-display);font-weight:600;font-size:clamp(18px,2vw,26px);line-height:1.35}
.t-h4{font-family:var(--font-display);font-weight:600;font-size:20px;line-height:1.4}
.t-body{font-size:16px;line-height:1.85}
.t-serif{font-family:var(--font-serif);font-size:17px;line-height:1.9}
.mono{font-family:var(--font-mono);letter-spacing:.06em}
.eyebrow{display:inline-flex;align-items:center;gap:8px;font-family:var(--font-mono);
  font-size:11.5px;letter-spacing:.14em;text-transform:uppercase;color:var(--sea-500)}
.eyebrow::before{content:"";width:8px;height:8px;border-radius:2px;background:var(--gold)}
.lead{font-size:17px;line-height:1.85;color:var(--slate);max-width:62ch}

/* ---------- 5. 布局 ---------- */
.page-shell{position:relative;z-index:1;margin-left:var(--rail-w);min-height:100vh;display:flex;flex-direction:column}
.page-main{flex:1 1 auto;width:min(1180px,100%);margin:0 auto;padding:44px 40px 80px}
.wrap{width:min(1180px,100%);margin:0 auto}
.section{padding:var(--gap-4) 0}
.section__head{display:flex;flex-wrap:wrap;align-items:baseline;gap:8px 18px;margin-bottom:var(--gap-3)}
.split{display:grid;grid-template-columns:minmax(0,7fr) minmax(0,4fr);gap:32px;align-items:start}
.rule{display:flex;align-items:center;gap:14px;margin:var(--gap-4) 0 var(--gap-3)}
.rule::after{content:"";flex:1 1 auto;height:1px;background:var(--line)}
.rule__num{font-family:var(--font-mono);font-size:12px;letter-spacing:.12em;color:var(--sea-500)}
.rule__label{font-family:var(--font-display);font-weight:600;font-size:14px;color:var(--sea-900)}
#main-content{scroll-margin-top:88px}

/* ---------- 6. 侧边轨道页头 ---------- */
.skip-link{position:fixed;top:10px;left:10px;z-index:200;padding:10px 16px;border-radius:10px;
  background:var(--gold);color:var(--sea-900);font-weight:700;font-size:14px;
  transform:translateY(-180%);transition:transform 200ms var(--ease)}
.skip-link:focus{transform:translateY(0)}

.site-rail{position:fixed;top:0;left:0;bottom:0;width:var(--rail-w);z-index:60;overflow:hidden;
  display:flex;flex-direction:column;gap:22px;padding:26px 22px 24px;
  background:linear-gradient(180deg,#0B2545 0%,#123A63 100%);color:var(--on-dark)}
.scroll-progress{position:fixed;top:0;left:var(--rail-w);right:0;height:3px;z-index:80;pointer-events:none;
  background:rgba(169,196,220,.35)}
.scroll-progress__bar{display:block;height:100%;width:0;
  background:linear-gradient(90deg,var(--gold) 0%,var(--gold-soft) 45%,var(--mint) 100%)}

.rail-top{display:flex;align-items:center;justify-content:space-between;gap:12px}
.rail-meta{display:flex;align-items:center;gap:6px;font-size:11px;letter-spacing:.1em;
  color:rgba(232,237,243,.55);text-transform:uppercase}
.rail-meta__code{color:var(--gold-soft)}
.rail-meta__sep{color:rgba(232,237,243,.32)}
.rail-meta__domain{color:rgba(232,237,243,.55)}

.rail-toggle{display:none;align-items:center;gap:8px;padding:8px 10px;border-radius:10px;
  border:1px solid rgba(232,237,243,.28);color:var(--on-dark);
  font-family:var(--font-mono);font-size:12px;letter-spacing:.08em;
  transition:border-color 200ms var(--ease),color 200ms var(--ease)}
.rail-toggle:hover{border-color:var(--gold-soft);color:#fff}
.rail-toggle__bars{display:inline-flex;flex-direction:column;gap:3px;width:16px}
.rail-toggle__bars i{display:block;height:2px;border-radius:2px;background:currentColor;
  transition:transform 220ms var(--ease),opacity 180ms var(--ease)}

.brand{display:flex;align-items:center;gap:12px;min-width:0}
.brand__mark{flex:0 0 auto;width:40px;height:40px;border-radius:12px;display:grid;place-items:center;
  color:var(--sea-900);background:linear-gradient(140deg,var(--gold-soft) 0%,var(--gold) 100%)}
.brand__text{display:flex;flex-direction:column;min-width:0}
.brand__name{font-family:var(--font-display);font-weight:700;font-size:18px;letter-spacing:.01em;color:#fff;line-height:1.3}
.brand__sub{font-size:10px;letter-spacing:.16em;color:var(--gold-soft);text-transform:uppercase}

.rail-quick{display:none;align-items:center;padding:9px 14px;border-radius:999px;white-space:nowrap;
  background:var(--gold);color:var(--sea-900);font-family:var(--font-display);
  font-weight:600;font-size:13px;transition:background-color 200ms var(--ease)}
.rail-quick:hover{background:var(--gold-soft)}

.rail-nav{flex:1 1 auto;min-height:0;overflow-y:auto;overflow-x:hidden;display:flex;flex-direction:column;gap:10px}
.rail-nav__title{font-size:10.5px;letter-spacing:.16em;text-transform:uppercase;
  color:rgba(232,237,243,.42);padding-left:12px}
.rail-nav__list{display:flex;flex-direction:column;gap:2px}
.rail-link{position:relative;display:grid;grid-template-columns:32px 1fr;align-items:center;gap:10px;
  padding:10px 12px;border-radius:10px;color:rgba(232,237,243,.78);
  transition:background-color 200ms var(--ease),color 200ms var(--ease),transform 200ms var(--ease)}
.rail-link__code{font-size:11px;letter-spacing:.08em;color:rgba(232,237,243,.4)}
.rail-link__label{font-family:var(--font-display);font-weight:500;font-size:14.5px}
.rail-link:hover{background:rgba(255,255,255,.08);color:#fff;transform:translateX(4px)}
.rail-link:hover .rail-link__code{color:var(--gold-soft)}
.rail-link[aria-current="page"]{background:rgba(201,162,39,.16);color:#fff}
.rail-link[aria-current="page"] .rail-link__code{color:var(--gold-soft)}
.rail-link[aria-current="page"]::before{content:"";position:absolute;left:0;top:8px;bottom:8px;width:3px;
  border-radius:2px;background:var(--gold)}

.rail-foot{margin-top:auto;padding-top:18px;border-top:1px dashed rgba(232,237,243,.2)}
.rail-foot__note{margin-bottom:12px;font-size:13px;line-height:1.7;color:rgba(232,237,243,.6)}

/* ---------- 7. 通用按钮 ---------- */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;
  padding:13px 22px;border-radius:999px;border:1px solid transparent;
  font-family:var(--font-display);font-weight:600;font-size:15px;line-height:1.2;
  cursor:pointer;transition:background-color 200ms var(--ease),color 200ms var(--ease),
    border-color 200ms var(--ease),transform 200ms var(--ease)}
.btn--gold{background:var(--gold);color:var(--sea-900)}
.btn--gold:hover{background:var(--gold-soft)}
.btn--sea{background:var(--sea-900);color:#fff}
.btn--sea:hover{background:var(--sea-500)}
.btn--line{background:transparent;border-color:var(--sea-500);color:var(--sea-500)}
.btn--line:hover{background:rgba(30,92,143,.08);color:var(--sea-900)}
.btn--sm{font-size:13.5px;padding:9px 16px}
.btn--block{width:100%}

/* ---------- 8. 页脚 ---------- */
.site-foot{position:relative;z-index:2;background:linear-gradient(180deg,#0B2545 0%,#123A63 100%);
  color:var(--on-dark);border-top:1px solid rgba(201,162,39,.45);padding:56px 40px 28px}
.site-foot::before{content:"";position:absolute;inset:0;z-index:0;pointer-events:none;opacity:.2;
  background-image:radial-gradient(rgba(255,255,255,.45) .5px,transparent .5px);background-size:3px 3px}
.site-foot__grid{position:relative;z-index:1;width:min(1180px,100%);margin:0 auto;
  display:grid;grid-template-columns:1.35fr 1fr 1.35fr;gap:40px 48px}
.site-foot__col{min-width:0}
.foot-brand{font-family:var(--font-display);font-weight:700;font-size:22px;color:#fff;letter-spacing:.01em;line-height:1.3}
.foot-slogan{margin-top:8px;font-size:15px;color:rgba(232,237,243,.75)}
.foot-lines{margin-top:20px;display:grid;gap:6px}
.foot-line{display:flex;align-items:center;gap:10px;padding:6px 0;font-size:14px;
  color:rgba(232,237,243,.82);transition:color 200ms var(--ease),transform 200ms var(--ease)}
.foot-line:hover{color:#fff;transform:translateX(3px)}
.foot-line__code{font-size:11px;letter-spacing:.1em;color:var(--gold-soft)}
.foot-title{font-family:var(--font-mono);font-weight:500;font-size:11px;letter-spacing:.14em;
  text-transform:uppercase;color:rgba(232,237,243,.5);margin-bottom:16px}
.foot-links{display:grid;gap:10px}
.foot-links a{display:inline-block;font-size:14px;color:rgba(232,237,243,.85);
  padding-bottom:2px;border-bottom:1px solid transparent;
  transition:color 200ms var(--ease),border-color 200ms var(--ease)}
.foot-links a:hover{color:var(--gold-soft);border-bottom-color:rgba(201,162,39,.55)}
.foot-contact{display:grid;gap:14px}
.foot-contact__row{display:flex;flex-wrap:wrap;align-items:center;gap:8px 10px;font-size:14px}
.foot-k{font-size:10.5px;letter-spacing:.12em;color:var(--gold-soft);min-width:46px}
.foot-value{color:#fff;word-break:break-all}
.foot-note{margin-top:16px;font-size:13px;line-height:1.7;color:rgba(232,237,243,.6);max-width:38ch}
.site-foot__base{position:relative;z-index:1;width:min(1180px,100%);margin:36px auto 0;padding-top:18px;
  border-top:1px solid rgba(232,237,243,.16);display:flex;flex-wrap:wrap;
  justify-content:space-between;gap:8px 24px}
.foot-meta{font-family:var(--font-mono);font-size:11px;letter-spacing:.06em;color:rgba(232,237,243,.55)}

/* ---------- 9. 内容组件 ---------- */
.crumbs{display:flex;flex-wrap:wrap;align-items:center;gap:8px;margin-bottom:24px;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.08em;color:var(--slate)}
.crumbs a:hover{color:var(--sea-500)}
.crumbs__sep{color:var(--line)}

.page-index{display:flex;flex-wrap:wrap;gap:10px 20px;padding:12px 16px;border-radius:14px;
  border:1px solid rgba(169,196,220,.6);background:rgba(255,255,255,.7);
  backdrop-filter:blur(8px);-webkit-backdrop-filter:blur(8px)}
.page-index__item{display:flex;align-items:center;gap:8px;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.08em}
.page-index__k{color:var(--slate)}
.page-index__v{color:var(--sea-900)}

.glass{border-radius:var(--radius);border:1px solid rgba(169,196,220,.6);
  background:rgba(255,255,255,.66);backdrop-filter:blur(10px);-webkit-backdrop-filter:blur(10px);
  padding:20px 22px}
.card{background:var(--white);border:1px solid var(--line-soft);border-radius:var(--radius);
  padding:24px 26px;box-shadow:var(--shadow-card)}
.card__title{font-family:var(--font-display);font-weight:600;font-size:18px;line-height:1.4;margin-bottom:8px;color:var(--ink)}
.card__meta{font-family:var(--font-mono);font-size:11px;letter-spacing:.08em;color:var(--slate)}

.chips{display:flex;flex-wrap:wrap;gap:8px}
.chip{display:inline-flex;align-items:center;gap:8px;padding:8px 14px;border-radius:999px;
  border:1px solid var(--line);background:rgba(255,255,255,.75);color:var(--sea-700);
  font-family:var(--font-mono);font-size:12px;letter-spacing:.06em;
  transition:background-color 200ms var(--ease),color 200ms var(--ease),border-color 200ms var(--ease)}
.chip:hover{border-color:var(--sea-500)}
.chip[aria-pressed="true"]{background:var(--sea-900);border-color:var(--sea-900);color:#fff}
.chip__count{color:var(--gold)}
.chip[aria-pressed="true"] .chip__count{color:var(--gold-soft)}

.acc{border-top:1px solid var(--line-soft)}
.acc__item{border-bottom:1px solid var(--line-soft)}
.acc__trigger{display:flex;width:100%;align-items:center;gap:14px;padding:16px 2px;text-align:left;
  font-family:var(--font-display);font-weight:600;font-size:16px;color:var(--ink);
  transition:color 200ms var(--ease)}
.acc__trigger:hover{color:var(--sea-500)}
.acc__code{flex:0 0 auto;font-family:var(--font-mono);font-size:11.5px;letter-spacing:.08em;color:var(--slate)}
.acc__label{flex:1 1 auto}
.acc__icon{flex:0 0 auto;position:relative;width:18px;height:18px;color:var(--sea-500)}
.acc__icon::before,.acc__icon::after{content:"";position:absolute;left:50%;top:50%;width:12px;height:2px;
  border-radius:2px;background:currentColor;transform:translate(-50%,-50%);
  transition:transform 260ms var(--ease)}
.acc__icon::after{transform:translate(-50%,-50%) rotate(90deg)}
.acc__item[data-open] .acc__icon::after{transform:translate(-50%,-50%) rotate(0deg)}
.acc__panel{display:grid;grid-template-rows:0fr;transition:grid-template-rows 260ms var(--ease)}
.acc__item[data-open] .acc__panel{grid-template-rows:1fr}
.acc__body{overflow:hidden;min-height:0}
.acc__inner{padding:0 2px 20px;max-width:70ch;font-size:15.5px;line-height:1.85;color:#33414f}

.figure{margin:0;border-radius:var(--radius);overflow:hidden;border:1px solid var(--line);
  background:linear-gradient(140deg,rgba(30,92,143,.16) 0%,rgba(201,162,39,.14) 55%,rgba(95,199,169,.16) 100%)}
.figure__media{position:relative;width:100%;aspect-ratio:16/10;overflow:hidden}
.figure__media>img,.figure__media>svg{width:100%;height:100%;object-fit:cover}
.figure--wide .figure__media{aspect-ratio:21/9}
.figure--square .figure__media{aspect-ratio:1/1}
.figure--tall .figure__media{aspect-ratio:4/5}
.figure__cap{padding:10px 14px;background:#fff;border-top:1px solid var(--line-soft);
  font-family:var(--font-mono);font-size:11px;letter-spacing:.06em;color:var(--slate)}

.pair{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:20px}
.pair__card{display:flex;flex-direction:column;gap:12px;padding:22px;border-radius:var(--radius);
  background:#fff;border:1px solid var(--line-soft);box-shadow:var(--shadow-card)}
.pair__head{display:flex;align-items:center;justify-content:space-between;gap:12px;
  padding-bottom:12px;border-bottom:1px dashed var(--line)}
.pair__name{font-family:var(--font-display);font-weight:600;font-size:17px;color:var(--ink)}
.pair__rows{display:grid;gap:2px}
.pair__row{display:flex;justify-content:space-between;gap:12px;padding:8px 0;font-size:14px;
  color:#33414f;border-bottom:1px solid rgba(169,196,220,.28)}
.pair__row:last-child{border-bottom:0}

.dots{display:flex;flex-wrap:wrap;gap:8px}
.dot{width:12px;height:12px;border-radius:50%;background:#fff;border:1.5px solid var(--line)}
.dot--done{background:var(--mint);border-color:var(--mint)}
.dot--now{background:var(--gold);border-color:var(--gold)}
.dot--todo{background:rgba(242,153,74,.2);border-color:var(--amber)}

.tag{display:inline-flex;align-items:center;gap:6px;padding:4px 10px;border-radius:999px;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.06em;
  background:rgba(30,92,143,.1);color:var(--sea-700)}
.tag--gold{background:rgba(201,162,39,.18);color:#7a6214}
.tag--mint{background:rgba(95,199,169,.2);color:#1f6b57}
.tag--amber{background:rgba(242,153,74,.2);color:#8a4d13}

.copy{display:inline-flex;align-items:center;padding:4px 10px;border-radius:999px;
  border:1px solid rgba(232,237,243,.32);color:rgba(232,237,243,.85);
  font-family:var(--font-mono);font-size:11px;letter-spacing:.06em;
  transition:background-color 200ms var(--ease),color 200ms var(--ease),border-color 200ms var(--ease)}
.copy:hover{border-color:var(--gold-soft);color:#fff}
.copy[data-copied="true"]{background:var(--mint);border-color:var(--mint);color:var(--sea-900)}
.copy--ink{border-color:var(--line);color:var(--sea-700)}
.copy--ink:hover{border-color:var(--sea-500);color:var(--sea-900)}
.copy--ink[data-copied="true"]{background:var(--mint);border-color:var(--mint);color:var(--sea-900)}

.anchor-list{position:sticky;top:32px;display:grid;gap:2px}
.anchor-list__link{display:block;padding:6px 0 6px 10px;border-left:2px solid transparent;
  font-family:var(--font-mono);font-size:11.5px;letter-spacing:.06em;color:var(--slate);
  transition:color 200ms var(--ease),border-color 200ms var(--ease)}
.anchor-list__link:hover{color:var(--sea-500)}
.anchor-list__link[aria-current="true"]{color:var(--sea-900);border-left-color:var(--gold)}

/* ---------- 10. 动效 ---------- */
.reveal{opacity:0;transform:translateY(12px);
  transition:opacity 320ms var(--ease),transform 320ms var(--ease)}
.reveal.is-in{opacity:1;transform:none}

/* ---------- 11. 响应式 ---------- */
@media (max-width:1280px){
  .page-main{padding:40px 32px 72px}
  .site-foot{padding:48px 32px 24px}
}
@media (max-width:1024px){
  :root{--rail-w:0px}
  body::after{display:none}
  .site-rail{left:0;right:0;bottom:auto;width:auto;height:var(--rail-top-h);
    flex-direction:row;align-items:center;gap:10px;padding:0 14px;overflow:visible;
    border-bottom:1px solid rgba(169,196,220,.22)}
  .rail-top{order:1;flex:0 0 auto;gap:8px}
  .rail-meta{display:none}
  .rail-toggle{display:inline-flex;order:1}
  .brand{order:2;flex:1 1 auto;gap:9px}
  .brand__mark{width:30px;height:30px;border-radius:9px}
  .brand__name{font-size:16px}
  .brand__sub{display:none}
  .rail-quick{order:3;display:inline-flex}
  .rail-foot{display:none}
  .rail-nav{order:4;position:fixed;top:var(--rail-top-h);left:0;right:0;z-index:59;
    max-height:calc(100vh - var(--rail-top-h));overflow-y:auto;
    display:block;padding:16px 16px 24px;background:var(--sea-900);
    border-bottom:1px solid rgba(169,196,220,.22);
    transform:translateY(-12px);opacity:0;visibility:hidden;
    transition:opacity 220ms var(--ease),transform 220ms var(--ease),visibility 220ms var(--ease)}
  .site-rail[data-open] .rail-nav{transform:translateY(0);opacity:1;visibility:visible}
  .site-rail[data-open] .rail-toggle__bars i:nth-child(1){transform:translateY(5px) rotate(45deg)}
  .site-rail[data-open] .rail-toggle__bars i:nth-child(2){opacity:0}
  .site-rail[data-open] .rail-toggle__bars i:nth-child(3){transform:translateY(-5px) rotate(-45deg)}
  .site-rail::after{content:"";position:fixed;inset:var(--rail-top-h) 0 0;z-index:58;
    background:rgba(11,37,69,.44);opacity:0;visibility:hidden;
    transition:opacity 220ms var(--ease),visibility 220ms var(--ease)}
  .site-rail[data-open]::after{opacity:1;visibility:visible}
  .rail-nav__title{padding-left:0;margin-bottom:6px}
  .rail-link{grid-template-columns:32px 1fr;padding:12px 10px}
  html.nav-open,html.nav-open body{overflow:hidden}
  .scroll-progress{left:0;top:var(--rail-top-h)}
  .page-shell{padding-top:var(--rail-top-h)}
  #main-content{scroll-margin-top:calc(var(--rail-top-h) + 14px)}
  .page-main{padding:28px 20px 64px}
  .site-foot{padding:40px 20px 24px}
  .site-foot__grid{grid-template-columns:1fr;gap:32px}
  .foot-note{max-width:none}
  .site-foot__base{margin-top:28px}
  .anchor-list{position:static}
}
@media (max-width:760px){
  body::before{background-image:repeating-linear-gradient(to bottom,rgba(169,196,220,.28) 0 1px,transparent 1px 72px)}
  .split{grid-template-columns:1fr;gap:24px}
  .pair{grid-template-columns:1fr}
  .page-main{padding:22px 16px 56px}
  .card,.pair__card{padding:20px}
  .site-foot{padding:36px 16px 22px}
}

/* ---------- 12. 动效降级 ---------- */
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{animation-duration:.001ms !important;animation-iteration-count:1 !important;
    transition-duration:.001ms !important}
  .reveal{opacity:1;transform:none}
  .scroll-progress__bar{transition:none}
}