/* =========================================================
   谈球吧体育 · 共享样式表
   文件路径：/assets/site.css
   作用：reset、变量、中文排版、页头、页脚、通用组件
   ========================================================= */

/* ---------- 1. 设计变量 ---------- */
:root{
  --ink-900:#071512;
  --ink-800:#0B1F1A;
  --line:#2A3431;
  --line-soft:rgba(42,52,49,.7);
  --moss:#3D5A4C;
  --mint:#3DF2B6;
  --aqua:#7FFFD4;
  --amber:#FFB347;
  --clay:#C96F4A;
  --paper:#F2EFE6;
  --white:#FFFFFF;
  --muted:#A8B5AE;
  --font-display:"PingFang SC","Source Han Sans SC","Noto Sans SC","Microsoft YaHei",system-ui,sans-serif;
  --font-body:"PingFang SC","Source Han Sans SC","Noto Sans SC","Helvetica Neue",Arial,system-ui,sans-serif;
  --font-mono:"JetBrains Mono","Roboto Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
  --wrap:1240px;
  --gutter:clamp(1rem,4vw,2.5rem);
  --cut:22px;
  --shadow-float:0 22px 44px -30px rgba(0,0,0,1);
  --ease:cubic-bezier(.22,.61,.36,1);
}

/* ---------- 2. Reset 与基础 ---------- */
*,
*::before,
*::after{box-sizing:border-box;}

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

body{
  margin:0;
  min-height:100vh;
  background-color:var(--ink-800);
  background-image:
    linear-gradient(90deg,rgba(42,52,49,.32) 1px,transparent 1px),
    linear-gradient(180deg,rgba(42,52,49,.24) 1px,transparent 1px);
  background-size:80px 80px,80px 80px;
  color:var(--paper);
  font-family:var(--font-body);
  font-size:17px;
  line-height:1.75;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}

h1,h2,h3,h4{
  margin:0;
  font-family:var(--font-display);
  font-weight:800;
  line-height:1.2;
  letter-spacing:-.01em;
  color:var(--white);
}

p{margin:0;}
ul,ol{margin:0;padding:0;list-style:none;}
img,svg{display:block;max-width:100%;}
button{font:inherit;color:inherit;}
a{color:var(--mint);text-decoration:none;transition:color .2s var(--ease);}
a:hover{color:var(--aqua);}

:focus-visible{
  outline:2px solid var(--aqua);
  outline-offset:3px;
  border-radius:6px;
}

::selection{background:var(--mint);color:var(--ink-900);}

#main-content{scroll-margin-top:120px;}

/* ---------- 3. 通用排版工具 ---------- */
.wrap{
  width:min(var(--wrap),calc(100% - var(--gutter) * 2));
  margin-inline:auto;
}
.wrap--narrow{
  width:min(860px,calc(100% - var(--gutter) * 2));
  margin-inline:auto;
}
.section{padding:clamp(3rem,7vw,6rem) 0;}
.section-head{
  display:flex;
  flex-wrap:wrap;
  align-items:flex-end;
  justify-content:space-between;
  gap:1.25rem;
  margin-bottom:clamp(1.5rem,3vw,2.5rem);
}
.eyebrow{
  display:inline-flex;
  align-items:center;
  gap:.6rem;
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.22em;
  text-transform:uppercase;
  color:var(--mint);
}
.eyebrow::before{
  content:"";
  width:26px;
  height:1px;
  background:var(--mint);
}
.section-title{
  margin:.6rem 0 0;
  font-size:clamp(1.75rem,3.4vw,2.4rem);
}
.lede{
  margin:.9rem 0 0;
  max-width:62ch;
  color:var(--muted);
  font-size:16.5px;
}
.mono{
  font-family:var(--font-mono);
  font-variant-numeric:tabular-nums;
}
.text-mint{color:var(--mint);}
.rule{
  height:1px;
  border:0;
  margin:0;
  background:linear-gradient(90deg,var(--mint),rgba(42,52,49,.5) 42%,transparent);
}

/* ---------- 4. 网格与分栏 ---------- */
.grid-2{
  display:grid;
  gap:clamp(1.25rem,2.5vw,2rem);
  grid-template-columns:repeat(auto-fit,minmax(280px,1fr));
}
.grid-3{
  display:grid;
  gap:clamp(1.15rem,2.2vw,1.75rem);
  grid-template-columns:repeat(auto-fit,minmax(240px,1fr));
}
.grid-split{
  display:grid;
  gap:clamp(1.5rem,3vw,2.75rem);
  grid-template-columns:minmax(0,1fr);
}
@media (min-width:960px){
  .grid-split{grid-template-columns:minmax(0,.85fr) minmax(0,1.15fr);}
}

/* ---------- 5. 按钮 ---------- */
.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:.55rem;
  padding:.8rem 1.35rem;
  border:1px solid var(--line);
  border-radius:999px;
  background:transparent;
  color:var(--paper);
  font-size:15px;
  font-weight:600;
  cursor:pointer;
  transition:transform .25s var(--ease),background-color .25s var(--ease),border-color .25s var(--ease),color .25s var(--ease);
}
.btn:hover{transform:translateY(-2px);}
.btn--primary{
  background:linear-gradient(140deg,var(--mint),var(--aqua));
  border-color:transparent;
  color:var(--ink-900);
}
.btn--primary:hover{color:var(--ink-900);}
.btn--ghost{border-color:rgba(61,242,182,.45);color:var(--mint);}
.btn--ghost:hover{background:rgba(61,242,182,.1);}
.btn--amber{border-color:rgba(255,179,71,.5);color:var(--amber);}
.btn--amber:hover{background:rgba(255,179,71,.12);color:var(--amber);}
.btn--clay{border-color:rgba(201,111,74,.55);color:var(--clay);}
.btn--clay:hover{background:rgba(201,111,74,.14);color:var(--clay);}

/* ---------- 6. 面板与数据件 ---------- */
.surface{
  position:relative;
  padding:clamp(1.25rem,2.4vw,1.9rem);
  border:1px solid var(--line);
  background:linear-gradient(160deg,rgba(42,52,49,.42),rgba(11,31,26,.92));
}
.surface--cut{
  clip-path:polygon(0 0,calc(100% - var(--cut)) 0,100% var(--cut),100% 100%,0 100%);
}
.surface--hoverable{
  transition:transform .3s var(--ease),border-color .3s var(--ease),box-shadow .3s var(--ease);
}
.surface--hoverable:hover{
  transform:translate(-2px,-4px);
  border-color:rgba(61,242,182,.45);
  box-shadow:0 26px 50px -34px rgba(0,0,0,1);
}

.stat{display:grid;gap:.3rem;}
.stat-value{
  font-family:var(--font-mono);
  font-size:clamp(1.6rem,3vw,2.1rem);
  font-weight:700;
  letter-spacing:-.02em;
  color:var(--mint);
  font-variant-numeric:tabular-nums;
}
.stat-label{
  font-size:13px;
  letter-spacing:.04em;
  color:var(--muted);
}

.marker{
  display:inline-grid;
  place-items:center;
  min-width:34px;
  height:34px;
  padding:0 .4rem;
  border:1px solid rgba(61,242,182,.45);
  border-radius:10px;
  background:rgba(61,242,182,.08);
  font-family:var(--font-mono);
  font-size:13px;
  color:var(--mint);
}

.tag{
  display:inline-flex;
  align-items:center;
  padding:.18rem .55rem;
  border:1px solid var(--line);
  border-radius:6px;
  font-family:var(--font-mono);
  font-size:11.5px;
  letter-spacing:.06em;
  color:var(--muted);
}
.tag--live{color:var(--mint);border-color:rgba(61,242,182,.45);background:rgba(61,242,182,.1);}
.tag--warn{color:var(--amber);border-color:rgba(255,179,71,.45);background:rgba(255,179,71,.1);}
.tag--out{color:var(--clay);border-color:rgba(201,111,74,.5);background:rgba(201,111,74,.12);}

.chip{
  display:inline-flex;
  align-items:center;
  gap:.35rem;
  padding:.3rem .65rem;
  border:1px solid var(--line);
  border-radius:999px;
  font-family:var(--font-mono);
  font-size:11.5px;
  letter-spacing:.06em;
  color:var(--muted);
}
.chip--ios{color:var(--amber);border-color:rgba(255,179,71,.4);}
.chip--android{color:var(--clay);border-color:rgba(201,111,74,.45);}
.chip--pad{color:var(--aqua);border-color:rgba(127,255,212,.35);}

/* ---------- 7. 面包屑 ---------- */
.breadcrumb{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:.5rem;
  font-family:var(--font-mono);
  font-size:12.5px;
  color:var(--muted);
}
.breadcrumb li{display:flex;align-items:center;gap:.5rem;}
.breadcrumb li:not(:last-child)::after{content:"/";color:var(--moss);}
.breadcrumb a{color:var(--muted);}
.breadcrumb a:hover{color:var(--mint);}
.breadcrumb [aria-current="page"]{color:var(--paper);}

/* ---------- 8. 图片容器基础规则 ---------- */
.frame-figure{
  position:relative;
  margin:0;
  border:1px solid var(--line);
  background:linear-gradient(150deg,rgba(61,242,182,.08),rgba(11,31,26,.92));
  overflow:hidden;
  clip-path:polygon(0 0,calc(100% - 24px) 0,100% 24px,100% 100%,0 100%);
}
.frame-figure img{
  width:100%;
  height:100%;
  object-fit:cover;
  aspect-ratio:16 / 10;
}
.frame-figure--wide img{aspect-ratio:21 / 9;}
.frame-figure--square img{aspect-ratio:1 / 1;}
.frame-figure--tall img{aspect-ratio:3 / 4;}
.frame-figure figcaption{
  padding:.85rem 1rem;
  border-top:1px solid var(--line);
  background:rgba(7,21,18,.75);
  font-size:13px;
  color:var(--muted);
}
.frame-placeholder{
  display:grid;
  place-items:center;
  aspect-ratio:16 / 10;
  padding:1.5rem;
  background-image:
    linear-gradient(90deg,rgba(42,52,49,.5) 1px,transparent 1px),
    linear-gradient(180deg,rgba(42,52,49,.5) 1px,transparent 1px);
  background-size:40px 40px,40px 40px;
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.12em;
  color:var(--muted);
  text-align:center;
}

/* ---------- 9. 显现动效钩子 ---------- */
[data-reveal]{
  opacity:0;
  transform:translateY(14px);
  transition:opacity .6s var(--ease),transform .6s var(--ease);
}
[data-reveal].is-visible{opacity:1;transform:none;}

/* ---------- 10. 页头 ---------- */
.site-header{
  position:sticky;
  top:0;
  z-index:80;
  background:linear-gradient(180deg,rgba(7,21,18,.97),rgba(11,31,26,.92));
  border-bottom:1px solid var(--line-soft);
  backdrop-filter:blur(14px);
  -webkit-backdrop-filter:blur(14px);
}
.site-header::before{
  content:"";
  position:absolute;
  inset:0;
  pointer-events:none;
  background-image:linear-gradient(90deg,rgba(42,52,49,.5) 1px,transparent 1px);
  background-size:72px 100%;
  opacity:.55;
}
.header-inner{
  position:relative;
  z-index:1;
  width:min(var(--wrap),calc(100% - var(--gutter) * 2));
  margin-inline:auto;
}

.skip-link{
  position:absolute;
  left:1rem;
  top:-5rem;
  z-index:200;
  padding:.7rem 1.1rem;
  border-radius:999px;
  background:var(--mint);
  color:var(--ink-900);
  font-size:14px;
  font-weight:700;
  transition:top .2s var(--ease);
}
.skip-link:focus{top:.75rem;color:var(--ink-900);}

/* 顶部信息轨 */
.header-topline{
  display:flex;
  align-items:center;
  gap:1.5rem;
  padding:.65rem 0;
  max-height:60px;
  overflow:hidden;
  border-bottom:1px dashed var(--line-soft);
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.08em;
  color:var(--muted);
  transition:max-height .35s var(--ease),opacity .25s var(--ease),padding .35s var(--ease),border-color .3s var(--ease);
}
.header-topline > *{
  white-space:nowrap;
  overflow:hidden;
  text-overflow:ellipsis;
}
.topline-brand{color:var(--paper);opacity:.78;}
.topline-ticker{
  flex:1 1 auto;
  min-width:0;
  display:flex;
  align-items:center;
  gap:.5rem;
  color:var(--muted);
}
.topline-dot{
  flex:0 0 auto;
  width:7px;
  height:7px;
  border-radius:50%;
  background:var(--mint);
  box-shadow:0 0 0 4px rgba(61,242,182,.14);
  animation:pulse 2.6s infinite;
}
.topline-coord{
  flex:0 0 auto;
  color:var(--moss);
}
@keyframes pulse{
  0%,100%{opacity:1;transform:scale(1);}
  50%{opacity:.45;transform:scale(.82);}
}

.site-header.is-condensed .header-topline{
  max-height:0;
  padding-top:0;
  padding-bottom:0;
  opacity:0;
  border-color:transparent;
}

/* 品牌 + 导航横条 */
.header-bar{
  position:relative;
  display:flex;
  align-items:center;
  gap:.9rem;
  padding:.9rem 0 1rem;
  transition:padding .35s var(--ease);
}
.site-header.is-condensed .header-bar{padding-top:.55rem;padding-bottom:.6rem;}

.brand{
  display:inline-flex;
  align-items:center;
  gap:.75rem;
  padding:.45rem 1.1rem .45rem .5rem;
  border:1px solid var(--line);
  border-radius:999px;
  background:rgba(11,31,26,.85);
  transition:border-color .25s var(--ease),transform .25s var(--ease),box-shadow .25s var(--ease);
}
.brand:hover{
  border-color:rgba(61,242,182,.5);
  transform:translateY(-2px);
  box-shadow:var(--shadow-float);
}
.brand-mark{
  display:grid;
  place-items:center;
  width:38px;
  height:38px;
  border-radius:12px;
  background:linear-gradient(150deg,var(--mint),#1F8F6D);
  color:var(--ink-900);
  font-size:18px;
  font-weight:800;
  clip-path:polygon(0 0,100% 0,100% 72%,74% 100%,0 100%);
}
.brand-text{display:flex;flex-direction:column;line-height:1.15;}
.brand-name{
  font-size:16.5px;
  font-weight:800;
  letter-spacing:.02em;
  color:var(--white);
}
.brand-sub{
  font-family:var(--font-mono);
  font-size:10.5px;
  letter-spacing:.14em;
  color:var(--muted);
}

.nav-pill{
  margin-left:auto;
  display:flex;
  align-items:center;
  gap:.4rem;
  padding:.4rem .45rem .4rem .5rem;
  border:1px solid var(--line);
  border-radius:999px;
  background:rgba(7,21,18,.88);
  box-shadow:0 14px 34px -28px rgba(0,0,0,1);
  transition:box-shadow .35s var(--ease),transform .35s var(--ease);
}
.site-header.is-condensed .nav-pill{
  box-shadow:0 22px 46px -22px rgba(0,0,0,1);
}

.nav-list{
  display:flex;
  align-items:center;
  gap:.1rem;
}
.nav-list a{
  display:inline-block;
  padding:.5rem .8rem;
  border-radius:999px;
  font-size:14.5px;
  font-weight:600;
  color:var(--paper);
  white-space:nowrap;
  transition:background-color .22s var(--ease),color .22s var(--ease),transform .22s var(--ease);
}
.nav-list a:hover{
  color:var(--aqua);
  background:rgba(61,242,182,.1);
  transform:translateY(-1px);
}
.nav-list a[aria-current="page"]{
  color:var(--ink-900);
  background:linear-gradient(140deg,var(--mint),var(--aqua));
}

.nav-divider{
  flex:0 0 auto;
  width:1px;
  height:22px;
  margin:0 .35rem;
  background:var(--line);
}

.nav-devices{
  display:flex;
  align-items:center;
  gap:.3rem;
}
.device-link{
  display:inline-block;
  padding:.42rem .7rem;
  border:1px solid transparent;
  border-radius:999px;
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.03em;
  white-space:nowrap;
  transition:transform .22s var(--ease),background-color .22s var(--ease),color .22s var(--ease);
}
.device-link:hover{transform:translateY(-1px);}
.device-link--ios{
  color:var(--amber);
  border-color:rgba(255,179,71,.45);
  background:rgba(255,179,71,.09);
}
.device-link--ios:hover{color:var(--amber);background:rgba(255,179,71,.18);}
.device-link--android{
  color:var(--clay);
  border-color:rgba(201,111,74,.5);
  background:rgba(201,111,74,.1);
}
.device-link--android:hover{color:var(--clay);background:rgba(201,111,74,.2);}
.device-link--pad{
  color:var(--aqua);
  border-color:rgba(127,255,212,.4);
  background:rgba(127,255,212,.08);
}
.device-link--pad:hover{color:var(--aqua);background:rgba(127,255,212,.16);}

.nav-toggle{
  display:none;
  align-items:center;
  gap:.55rem;
  margin-left:auto;
  padding:.55rem .95rem;
  border:1px solid var(--line);
  border-radius:999px;
  background:rgba(11,31,26,.9);
  color:var(--paper);
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.12em;
  cursor:pointer;
  transition:border-color .25s var(--ease),color .25s var(--ease),transform .25s var(--ease);
}
.nav-toggle:hover{
  border-color:rgba(61,242,182,.5);
  color:var(--aqua);
  transform:translateY(-1px);
}
.nav-toggle-text{line-height:1;}
.nav-toggle-bars{
  position:relative;
  flex:0 0 auto;
  width:18px;
  height:2px;
  border-radius:2px;
  background:currentColor;
}
.nav-toggle-bars::before,
.nav-toggle-bars::after{
  content:"";
  position:absolute;
  left:0;
  width:18px;
  height:2px;
  border-radius:2px;
  background:currentColor;
  transition:transform .25s var(--ease);
}
.nav-toggle-bars::before{top:-6px;}
.nav-toggle-bars::after{top:6px;}
.nav-toggle[aria-expanded="true"] .nav-toggle-bars{background:transparent;}
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::before{transform:translateY(6px) rotate(45deg);}
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::after{transform:translateY(-6px) rotate(-45deg);}

.scroll-progress{
  position:absolute;
  left:0;
  bottom:-1px;
  width:100%;
  height:2px;
  background:linear-gradient(90deg,var(--moss),var(--mint));
  transform:scaleX(0);
  transform-origin:0 50%;
  transition:transform .12s linear;
}

/* ---------- 11. 页头响应式 ---------- */
@media (max-width:1100px){
  .header-topline{font-size:11px;gap:1rem;}
  .topline-coord{display:none;}

  .nav-toggle{display:inline-flex;}

  .nav-pill{
    position:absolute;
    left:0;
    right:0;
    top:calc(100% + .6rem);
    margin-left:0;
    flex-direction:column;
    align-items:stretch;
    gap:.5rem;
    padding:.85rem;
    border-radius:20px;
    background:linear-gradient(180deg,rgba(7,21,18,.99),rgba(11,31,26,.99));
    box-shadow:0 30px 60px -30px rgba(0,0,0,1);
    max-height:calc(100vh - 8rem);
    overflow:auto;
    opacity:0;
    visibility:hidden;
    transform:translateY(-10px);
    pointer-events:none;
    transition:opacity .25s var(--ease),transform .25s var(--ease),visibility .25s var(--ease);
  }
  .nav-pill[data-open]{
    opacity:1;
    visibility:visible;
    transform:none;
    pointer-events:auto;
  }
  .nav-list{
    flex-direction:column;
    align-items:stretch;
    gap:.15rem;
  }
  .nav-list a{
    display:block;
    padding:.7rem .9rem;
    border-radius:14px;
    font-size:15.5px;
  }
  .nav-divider{
    width:100%;
    height:1px;
    margin:.4rem 0;
  }
  .nav-devices{flex-wrap:wrap;gap:.4rem;}
  .device-link{padding:.5rem .8rem;}
}

@media (max-width:720px){
  :root{--gutter:1rem;}
  .brand-sub{display:none;}
  .brand{padding-right:.85rem;}
  .topline-brand{display:none;}
  .header-topline{font-size:10.5px;}
}

/* ---------- 12. 页脚 ---------- */
.site-footer{
  position:relative;
  margin-top:5rem;
  border-top:1px solid var(--line);
  background:linear-gradient(180deg,var(--ink-800),var(--ink-900) 46%);
  overflow:hidden;
}
.site-footer::before{
  content:"";
  position:absolute;
  inset:0;
  pointer-events:none;
  background-image:linear-gradient(90deg,rgba(42,52,49,.45) 1px,transparent 1px);
  background-size:72px 100%;
  opacity:.5;
}
.site-footer::after{
  content:"";
  position:absolute;
  top:0;
  left:0;
  width:min(320px,42%);
  height:3px;
  background:linear-gradient(90deg,var(--mint),transparent);
}
.footer-inner{
  position:relative;
  z-index:1;
  width:min(var(--wrap),calc(100% - var(--gutter) * 2));
  margin-inline:auto;
}
.footer-grid{
  display:grid;
  grid-template-columns:1.6fr 1fr 1fr 1.3fr;
  gap:clamp(1.5rem,3vw,3rem);
  padding:clamp(2.5rem,5vw,4.5rem) 0 clamp(1.75rem,3vw,2.75rem);
}
.footer-brand{min-width:0;}
.footer-mark{
  display:grid;
  place-items:center;
  width:44px;
  height:44px;
  border-radius:14px;
  background:linear-gradient(150deg,var(--mint),#1F8F6D);
  color:var(--ink-900);
  font-size:19px;
  font-weight:800;
  clip-path:polygon(0 0,100% 0,100% 72%,74% 100%,0 100%);
}
.footer-name{
  margin:.9rem 0 .35rem;
  font-size:20px;
  font-weight:800;
  letter-spacing:.02em;
  color:var(--white);
}
.footer-desc{
  max-width:36ch;
  font-size:14.5px;
  line-height:1.75;
  color:var(--muted);
}
.footer-chips{
  display:flex;
  flex-wrap:wrap;
  gap:.4rem;
  margin-top:1.1rem;
}

.footer-col{min-width:0;}
.footer-contact{min-width:0;}
.footer-heading{
  display:flex;
  align-items:center;
  gap:.6rem;
  margin:0 0 1rem;
  font-family:var(--font-mono);
  font-size:11.5px;
  font-weight:600;
  letter-spacing:.18em;
  color:var(--aqua);
}
.footer-heading::after{
  content:"";
  flex:1;
  height:1px;
  background:linear-gradient(90deg,rgba(127,255,212,.4),transparent);
}
.footer-links{display:grid;gap:.55rem;}
.footer-links a{
  font-size:14.5px;
  color:var(--paper);
  transition:color .2s var(--ease),padding-left .2s var(--ease);
}
.footer-links a:hover{
  color:var(--mint);
  padding-left:.35rem;
}

.footer-contact-list{display:grid;gap:.75rem;}
.footer-contact-list li{display:grid;gap:.15rem;}
.footer-label{
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.14em;
  color:var(--muted);
  opacity:.75;
}
.footer-value{
  font-size:14px;
  line-height:1.7;
  color:var(--paper);
  word-break:break-word;
}
.footer-value--mono{
  font-family:var(--font-mono);
  letter-spacing:.02em;
}

.footer-base{
  display:grid;
  grid-template-columns:auto auto minmax(0,1fr) auto;
  align-items:center;
  gap:1rem 2rem;
  padding:1.4rem 0 2rem;
  border-top:1px solid var(--line);
  font-size:13px;
  color:var(--muted);
}
.footer-copy{
  font-family:var(--font-mono);
  letter-spacing:.04em;
}
.footer-legal{
  font-family:var(--font-mono);
  color:var(--paper);
  opacity:.8;
}
.footer-note{
  font-size:12.5px;
  line-height:1.7;
  color:rgba(168,181,174,.85);
}
.to-top{
  display:inline-flex;
  align-items:center;
  gap:.5rem;
  padding:.5rem .95rem;
  border:1px solid var(--line);
  border-radius:999px;
  background:transparent;
  color:var(--paper);
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.1em;
  cursor:pointer;
  transition:border-color .25s var(--ease),color .25s var(--ease),transform .25s var(--ease);
}
.to-top::before{
  content:"\2191";
  font-size:14px;
  line-height:1;
}
.to-top:hover{
  border-color:rgba(61,242,182,.5);
  color:var(--mint);
  transform:translateY(-2px);
}

@media (max-width:1000px){
  .footer-grid{grid-template-columns:1fr 1fr;}
  .footer-base{grid-template-columns:1fr 1fr;}
  .footer-note{grid-column:1 / -1;}
  .to-top{justify-self:start;}
}
@media (max-width:640px){
  .footer-grid{grid-template-columns:1fr;}
  .footer-base{grid-template-columns:1fr;justify-items:start;gap:.75rem;}
  .footer-note{grid-column:auto;}
  .site-footer{margin-top:3rem;}
}

/* ---------- 13. 动效偏好 ---------- */
@media (prefers-reduced-motion: reduce){
  html{scroll-behavior:auto;}
  *,
  *::before,
  *::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
  }
  .topline-dot{animation:none;}
  [data-reveal]{opacity:1;transform:none;}
  .scroll-progress{transition:none;}
}