/* ============================================================
   乐竞赛事 Site Kit — 共享样式
   包含：Reset / CSS 变量 / 中文排版 / 头部 / 页脚 /
   通用按钮 / 面包屑 / 正文容器 / 网格 / 基础组件
   ============================================================ */

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

:root{
  --c-ice:#D4F1F4;
  --c-lake:#0FB5BA;
  --c-volt:#00D3A7;
  --c-sun:#FFC91F;
  --c-ink:#0A2A3A;
  --c-mist:#F2F4F7;
  --c-white:#FFFFFF;
  --c-gray:#66727A;
  --c-ink-70:rgba(10,42,58,.7);
  --c-ink-40:rgba(10,42,58,.4);
  --c-ink-12:rgba(10,42,58,.12);
  --c-ink-08:rgba(10,42,58,.08);
  --c-white-85:rgba(255,255,255,.85);
  --c-white-70:rgba(255,255,255,.7);
  --c-white-60:rgba(255,255,255,.6);
  --c-white-45:rgba(255,255,255,.45);
  --c-white-25:rgba(255,255,255,.25);
  --c-white-12:rgba(255,255,255,.12);
  --font-sans:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei","Noto Sans SC","Source Han Sans SC",sans-serif;
  --font-mono:"SF Mono","Cascadia Code","Roboto Mono",Consolas,"Liberation Mono",monospace;
  --cut:16px;
  --container-w:1200px;
  --header-h:76px;
  --header-h-m:64px;
  --pad-x:clamp(18px,4vw,48px);
  --sec-y:clamp(56px,9vw,116px);
  --ease:cubic-bezier(.22,.61,.36,1);
  --shadow-1:0 6px 18px rgba(10,42,58,.06);
  --shadow-2:0 14px 34px rgba(10,42,58,.14);
}

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

body{
  font-family:var(--font-sans);
  font-size:16px;
  line-height:1.75;
  color:var(--c-ink);
  background:var(--c-white);
  overflow-x:hidden;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}

main{ display:block; }
img{ max-width:100%; display:block; height:auto; }
a{ color:inherit; text-decoration:none; }
ul,ol{ list-style:none; }
button,input,select,textarea{ font:inherit; color:inherit; }
address{ font-style:normal; }
::selection{ background:var(--c-sun); color:var(--c-ink); }

:focus-visible{
  outline:2px dotted var(--c-ink);
  outline-offset:3px;
  border-radius:2px;
}
.site-header :focus-visible,
.site-nav :focus-visible,
.site-footer :focus-visible,
.section--ink :focus-visible{
  outline-color:var(--c-sun);
}

#main-content{ scroll-margin-top:var(--header-h); }

/* ---------- 容器与章节 ---------- */
.container{
  max-width:var(--container-w);
  margin-inline:auto;
  padding-inline:var(--pad-x);
}

.section{ padding-block:var(--sec-y); position:relative; }
.section--ice{ background:var(--c-ice); }
.section--mist{ background:var(--c-mist); }
.section--white{ background:var(--c-white); }
.section--ink{
  background:
    radial-gradient(900px 420px at 88% 110%, rgba(0,211,167,.16), transparent 62%),
    var(--c-ink);
  color:var(--c-white-85);
}
.section--sun{ background:var(--c-sun); color:var(--c-ink); }

.page-hero{
  position:relative;
  padding:calc(var(--header-h) + clamp(36px,7vw,84px)) var(--pad-x) clamp(40px,7vw,88px);
  background:
    radial-gradient(1100px 480px at 88% -8%, rgba(15,181,186,.28), transparent 62%),
    linear-gradient(135deg,var(--c-ice) 0%,var(--c-mist) 100%);
  overflow:hidden;
}
.page-hero--ink{
  background:
    radial-gradient(760px 380px at 82% 118%, rgba(0,211,167,.2), transparent 60%),
    var(--c-ink);
  color:var(--c-white-85);
}

/* ---------- 跳转链接 ---------- */
.skip-link{
  position:fixed;
  top:12px;
  left:12px;
  z-index:2000;
  background:var(--c-ink);
  color:#fff;
  font-size:14px;
  font-weight:700;
  padding:10px 18px;
  transform:translateY(-220%);
  transition:transform .25s var(--ease);
  box-shadow:0 4px 14px rgba(10,42,58,.28);
}
.skip-link:focus{ transform:translateY(0); }

/* ---------- 头部 ---------- */
.site-header{
  position:fixed;
  top:0;
  left:0;
  right:0;
  z-index:1000;
  height:var(--header-h);
  background-color:rgba(10,42,58,.28);
  transition:background-color .35s var(--ease),box-shadow .35s var(--ease);
}
.site-header::before{
  content:"";
  position:absolute;
  inset:0;
  z-index:0;
  background:linear-gradient(to bottom,rgba(10,42,58,.82) 0%,rgba(10,42,58,.42) 58%,rgba(10,42,58,0) 100%);
  transition:opacity .35s var(--ease);
  pointer-events:none;
}
.site-header::after{
  content:"";
  position:absolute;
  left:0;
  bottom:0;
  z-index:24;
  height:3px;
  width:calc(var(--scroll,0) * 100%);
  background:linear-gradient(90deg,var(--c-lake) 0%,var(--c-volt) 52%,var(--c-sun) 100%);
  pointer-events:none;
}
.site-header[data-scrolled]{
  background-color:var(--c-ink);
  box-shadow:0 6px 24px rgba(4,18,26,.34);
}
.site-header[data-scrolled]::before{ opacity:0; }

.site-header__inner{
  position:relative;
  z-index:6;
  max-width:var(--container-w);
  margin-inline:auto;
  height:var(--header-h);
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:24px;
  padding-inline:var(--pad-x);
}

/* ---------- 品牌 ---------- */
.site-brand{
  position:relative;
  z-index:5;
  display:inline-flex;
  align-items:center;
  gap:11px;
  flex:none;
}
.site-brand__mark{
  display:grid;
  place-items:center;
  width:38px;
  height:38px;
  background:linear-gradient(135deg,var(--c-sun) 0%,#ffb800 72%);
  color:var(--c-ink);
  font-size:19px;
  font-weight:900;
  clip-path:polygon(0 0,100% 0,100% 72%,72% 100%,0 100%);
}
.site-brand__text{
  display:flex;
  flex-direction:column;
  line-height:1.12;
}
.site-brand__cn{
  font-size:21px;
  font-weight:900;
  letter-spacing:.08em;
  color:#fff;
}
.site-brand__en{
  margin-top:3px;
  font-family:var(--font-mono);
  font-size:9px;
  letter-spacing:.3em;
  color:var(--c-volt);
  text-transform:uppercase;
}
.site-brand--footer .site-brand__cn{ font-size:23px; }

/* ---------- 导航 ---------- */
.site-nav{
  position:relative;
  z-index:1;
  display:flex;
  align-items:center;
  gap:22px;
}

.site-nav__list{
  display:flex;
  align-items:center;
  gap:2px;
}
.site-nav__list a{
  position:relative;
  display:inline-block;
  padding:9px 12px;
  font-size:15px;
  font-weight:600;
  letter-spacing:.06em;
  color:var(--c-white-85);
  white-space:nowrap;
  transition:color .25s var(--ease);
}
.site-nav__list a::after{
  content:"";
  position:absolute;
  left:12px;
  right:12px;
  bottom:2px;
  height:2px;
  background:var(--c-sun);
  transform:scaleX(0);
  transform-origin:left;
  transition:transform .28s var(--ease);
}
.site-nav__list a:hover{ color:#fff; }
.site-nav__list a:hover::after,
.site-nav__list a[aria-current="page"]::after{ transform:scaleX(1); }
.site-nav__list a[aria-current="page"]{ color:#fff; }

.site-hotline{
  display:inline-flex;
  align-items:center;
  gap:9px;
  margin-left:4px;
  padding:7px 14px;
  font-family:var(--font-mono);
  font-size:13px;
  letter-spacing:.05em;
  color:#fff;
  border:1px solid var(--c-white-25);
  border-radius:2px;
  background:rgba(255,255,255,.06);
  white-space:nowrap;
}
.site-hotline::before{
  content:"";
  width:7px;
  height:7px;
  border-radius:50%;
  background:var(--c-volt);
  animation:hotPulse 2.2s infinite ease-out;
}
@keyframes hotPulse{
  0%,100%{ box-shadow:0 0 0 0 rgba(0,211,167,.55); }
  55%{ box-shadow:0 0 0 7px rgba(0,211,167,0); }
}

/* ---------- 移动菜单按钮 ---------- */
.site-nav-toggle{
  display:none;
  position:relative;
  z-index:5;
  width:48px;
  height:48px;
  align-items:flex-end;
  flex-direction:column;
  justify-content:center;
  gap:6px;
  padding:12px;
  background:transparent;
  border:0;
  cursor:pointer;
  color:#fff;
}
.site-nav-toggle__bar{
  display:block;
  width:24px;
  height:2px;
  background:currentColor;
  transition:transform .3s var(--ease),opacity .25s var(--ease),width .3s var(--ease);
}
.site-nav-toggle__bar:nth-child(2){ width:17px; }
.site-nav-toggle[aria-expanded="true"] .site-nav-toggle__bar:nth-child(1){
  transform:translateY(8px) rotate(45deg);
  width:24px;
}
.site-nav-toggle[aria-expanded="true"] .site-nav-toggle__bar:nth-child(2){
  opacity:0;
  transform:translateX(6px);
}
.site-nav-toggle[aria-expanded="true"] .site-nav-toggle__bar:nth-child(3){
  transform:translateY(-8px) rotate(-45deg);
}

html.nav-lock{ overflow:hidden; }

/* ---------- 页脚 ---------- */
.site-footer{
  position:relative;
  background:
    linear-gradient(90deg,var(--c-ink) 0%,#071e2b 58%,#062130 100%);
  color:var(--c-white-85);
  overflow:hidden;
}
.site-footer__band{
  height:6px;
  background:linear-gradient(90deg,var(--c-lake) 0%,var(--c-volt) 52%,var(--c-sun) 100%);
}
.site-footer__inner{
  display:grid;
  grid-template-columns:1.7fr 1fr 1.4fr;
  gap:clamp(28px,5vw,64px);
  padding-block:clamp(50px,8vw,88px) clamp(40px,6vw,60px);
  align-items:start;
}
.site-footer__desc{
  margin-top:18px;
  max-width:40ch;
  font-size:14px;
  line-height:1.9;
  color:var(--c-white-60);
}
.site-footer__col{ min-width:0; }
.site-footer__col--contact{ align-self:start; }
.site-footer__head{
  display:flex;
  align-items:center;
  gap:10px;
  margin-bottom:20px;
  font-size:13px;
  font-weight:800;
  letter-spacing:.18em;
  color:var(--c-sun);
}
.site-footer__head::after{
  content:"";
  width:26px;
  height:1px;
  background:var(--c-white-25);
}
.site-footer__list li{ margin-block:4px; }
.site-footer__list a{
  display:inline-flex;
  align-items:baseline;
  gap:9px;
  padding-block:5px;
  font-size:15px;
  color:var(--c-white-70);
  transition:color .25s var(--ease),transform .25s var(--ease);
}
.site-footer__list a::before{
  content:"→";
  font-family:var(--font-mono);
  font-size:12px;
  color:var(--c-volt);
}
.site-footer__list a:hover{
  color:var(--c-sun);
  transform:translateX(4px);
}
.site-footer__contact{
  display:grid;
  gap:10px;
}
.site-footer__contact span{
  display:flex;
  align-items:flex-start;
  gap:12px;
  font-size:14px;
  line-height:1.7;
  color:var(--c-white-65);
  padding-block:3px;
}
.site-footer__contact span::before{
  content:attr(data-tag);
  flex:none;
  margin-top:3px;
  padding:2px 6px;
  font-family:var(--font-mono);
  font-size:10px;
  letter-spacing:.08em;
  color:var(--c-sun);
  border:1px solid var(--c-white-25);
  border-radius:2px;
}
.site-footer__bottom{
  border-top:1px solid var(--c-white-12);
  padding-block:18px;
}
.site-footer__meta{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  justify-content:space-between;
  gap:8px 28px;
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.04em;
  color:var(--c-white-45);
}

/* ---------- 标题与正文 ---------- */
.title-lg{
  font-size:clamp(32px,6vw,58px);
  font-weight:900;
  line-height:1.12;
  letter-spacing:.02em;
  color:var(--c-ink);
}
.title-md{
  font-size:clamp(24px,4vw,38px);
  font-weight:900;
  line-height:1.18;
  color:var(--c-ink);
}
.title-sm{
  font-size:clamp(18px,2.4vw,24px);
  font-weight:800;
  line-height:1.32;
  color:var(--c-ink);
}
.lead{
  font-size:clamp(17px,2vw,19px);
  line-height:1.85;
  color:var(--c-ink-70);
}
.note{
  font-size:14px;
  line-height:1.8;
  color:var(--c-gray);
}
.num{
  font-family:var(--font-mono);
  font-variant-numeric:tabular-nums;
  letter-spacing:-.02em;
}

/* ---------- 章节头 ---------- */
.sec-head{
  display:flex;
  align-items:flex-end;
  gap:16px;
  margin-bottom:clamp(28px,4vw,46px);
}
.sec-head__index{
  flex:none;
  padding:7px 11px;
  font-family:var(--font-mono);
  font-size:13px;
  font-weight:600;
  line-height:1;
  color:var(--c-ink);
  background:var(--c-sun);
  clip-path:polygon(0 0,100% 0,calc(100% - 8px) 100%,0 100%);
}
.sec-head__title{
  font-weight:900;
  font-size:clamp(26px,4vw,42px);
  line-height:1.15;
  color:var(--c-ink);
}
.sec-head__line{
  flex:1;
  height:2px;
  margin-bottom:9px;
  background:linear-gradient(90deg,var(--c-lake),rgba(15,181,186,0));
}
.sec-head__note{
  flex:none;
  writing-mode:vertical-rl;
  text-orientation:mixed;
  font-size:12px;
  letter-spacing:.32em;
  color:var(--c-gray);
  padding-left:6px;
}
.section--ink .sec-head__title{ color:#fff; }
.section--ink .sec-head__note{ color:var(--c-white-45); }

.aside-label{
  display:inline-flex;
  align-items:center;
  gap:8px;
  writing-mode:vertical-rl;
  text-orientation:mixed;
  font-size:12px;
  letter-spacing:.34em;
  color:var(--c-gray);
}
.aside-label::before{
  content:"";
  width:3px;
  height:34px;
  background:var(--c-sun);
}

/* ---------- 网格 ---------- */
.grid{
  display:grid;
  grid-template-columns:repeat(12,1fr);
  gap:clamp(16px,2.4vw,28px);
}
.grid--2{ grid-template-columns:repeat(2,1fr); }
.grid--3{ grid-template-columns:repeat(3,1fr); }
.grid--4{ grid-template-columns:repeat(4,1fr); }
.span-2{ grid-column:span 2; }
.span-3{ grid-column:span 3; }
.span-4{ grid-column:span 4; }
.span-5{ grid-column:span 5; }
.span-6{ grid-column:span 6; }
.span-7{ grid-column:span 7; }
.span-8{ grid-column:span 8; }
.span-12{ grid-column:span 12; }

/* ---------- 按钮 ---------- */
.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:10px;
  min-height:46px;
  padding:12px 26px;
  font-size:15px;
  font-weight:700;
  letter-spacing:.06em;
  color:#fff;
  background:var(--c-lake);
  border:0;
  cursor:pointer;
  clip-path:polygon(0 0,calc(100% - 12px) 0,100% 12px,100% 100%,0 100%);
  transition:filter .28s var(--ease),transform .28s var(--ease),background-color .28s;
}
.btn--primary{ background:var(--c-lake); color:#fff; }
.btn--primary:hover{
  filter:brightness(1.08) drop-shadow(0 6px 14px rgba(15,181,186,.34));
  transform:translateY(-2px);
}
.btn--sun{
  background:var(--c-sun);
  color:var(--c-ink);
  clip-path:polygon(0 0,100% 0,100% calc(100% - 10px),calc(100% - 10px) 100%,0 100%);
}
.btn--sun:hover{
  filter:brightness(1.05) drop-shadow(0 6px 14px rgba(255,201,31,.4));
  transform:translateY(-2px);
}
.btn--ghost{
  background:transparent;
  color:var(--c-ink);
  border:2px solid var(--c-ink);
  clip-path:polygon(0 0,calc(100% - 12px) 0,100% 12px,100% 100%,0 100%);
}
.btn--ghost:hover{
  background:var(--c-ink);
  color:#fff;
  transform:translateY(-2px);
}
.btn--sm{ min-height:36px; padding:8px 16px; font-size:13px; }

/* ---------- 卡片 ---------- */
.cut-card{
  --cut:16px;
  position:relative;
  background:var(--c-white);
  padding:clamp(22px,3vw,34px);
  border:1px solid var(--c-ink-08);
  clip-path:polygon(0 0,calc(100% - var(--cut)) 0,100% var(--cut),100% 100%,0 100%);
  filter:drop-shadow(0 4px 12px rgba(10,42,58,.05));
  transition:transform .3s var(--ease),filter .3s var(--ease),border-color .3s var(--ease);
}
.cut-card::after{
  content:"";
  position:absolute;
  left:0;
  bottom:0;
  height:4px;
  width:100%;
  background:linear-gradient(90deg,var(--c-lake),var(--c-volt));
  transform:scaleX(.16);
  transform-origin:left;
  transition:transform .35s var(--ease);
}
.cut-card:hover{
  border-color:var(--c-lake);
  filter:drop-shadow(0 12px 24px rgba(10,42,58,.12));
  transform:translateY(-4px);
}
.cut-card:hover::after{ transform:scaleX(1); }
.cut-card--ice{ background:var(--c-ice); }
.cut-card--mist{ background:var(--c-mist); }
.cut-card--ink{
  background:var(--c-ink);
  color:var(--c-white-85);
  border-color:rgba(255,255,255,.08);
}

/* ---------- 图片容器 ---------- */
.media{
  position:relative;
  overflow:hidden;
  aspect-ratio:16/9;
  background-color:var(--c-ice);
  background-image:
    linear-gradient(135deg,rgba(15,181,186,.14) 25%,transparent 25.5%),
    linear-gradient(45deg,rgba(255,201,31,.16) 25%,transparent 25.5%);
  background-size:40px 40px,40px 40px;
  background-position:center center;
}
.media--square{ aspect-ratio:1/1; }
.media--wide{ aspect-ratio:21/9; }
.media--portrait{ aspect-ratio:3/4; }
.media--fill{
  background-image:
    linear-gradient(135deg,rgba(15,181,186,.14) 25%,transparent 25.5%),
    linear-gradient(45deg,rgba(255,201,31,.16) 25%,transparent 25.5%),
    var(--img,none);
  background-size:40px 40px,40px 40px,cover;
}
.media::after{
  content:attr(data-label);
  position:absolute;
  right:10px;
  bottom:10px;
  padding:3px 9px;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.18em;
  color:var(--c-ink);
  background:var(--c-sun);
  clip-path:polygon(0 0,100% 0,calc(100% - 6px) 100%,0 100%);
}

/* ---------- 标签 ---------- */
.chip{
  display:inline-flex;
  align-items:center;
  gap:6px;
  padding:5px 12px;
  font-size:12px;
  font-weight:700;
  letter-spacing:.08em;
  color:var(--c-ink);
  background:var(--c-mist);
  border-radius:2px;
}
.chip--sun{ background:var(--c-sun); }
.chip--lake{ background:var(--c-lake); color:#fff; }
.chip--line{
  background:transparent;
  border:1px solid var(--c-ink-12);
  color:var(--c-gray);
}

/* ---------- 数据指标 ---------- */
.kpi{
  display:grid;
  gap:6px;
}
.kpi__num{
  font-family:var(--font-mono);
  font-variant-numeric:tabular-nums;
  font-size:clamp(30px,4.4vw,46px);
  font-weight:700;
  line-height:1;
  color:var(--c-lake);
  letter-spacing:-.02em;
}
.kpi__num small{
  font-size:.5em;
  font-weight:400;
  color:var(--c-gray);
  margin-left:6px;
}
.kpi__label{
  font-size:13px;
  letter-spacing:.1em;
  color:var(--c-gray);
}
.cut-card--ink .kpi__num{ color:var(--c-sun); }
.cut-card--ink .kpi__num small{ color:var(--c-white-45); }
.cut-card--ink .kpi__label{ color:var(--c-white-60); }

/* ---------- 滚动数据条 ---------- */
.ticker{
  overflow:hidden;
  background:var(--c-ink);
  color:var(--c-white);
  position:relative;
}
.ticker__track{
  display:flex;
  width:max-content;
  animation:tickerScroll 32s linear infinite;
}
.ticker:hover .ticker__track,
.ticker:focus-within .ticker__track{ animation-play-state:paused; }
.ticker__item{
  display:inline-flex;
  align-items:center;
  padding:14px 28px;
  white-space:nowrap;
  font-family:var(--font-mono);
  font-size:14px;
  letter-spacing:.03em;
  color:var(--c-white-70);
}
.ticker__item b{
  color:var(--c-sun);
  font-weight:700;
  margin-inline:8px;
}
.ticker__item::after{
  content:"◆";
  margin-left:28px;
  font-size:8px;
  color:var(--c-lake);
}
@keyframes tickerScroll{
  from{ transform:translateX(0); }
  to{ transform:translateX(-50%); }
}

/* ---------- 面包屑 ---------- */
.breadcrumb{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:4px 0;
  padding-block:16px;
  font-size:13px;
  color:var(--c-gray);
}
.breadcrumb li{ display:flex; align-items:center; }
.breadcrumb a{
  color:var(--c-lake);
  font-weight:600;
  transition:color .2s var(--ease);
}
.breadcrumb a:hover{ color:var(--c-ink); }
.breadcrumb li + li::before{
  content:"/";
  margin-inline:10px;
  color:var(--c-ink-40);
  font-family:var(--font-mono);
}

/* ---------- 折叠问答 ---------- */
.acc{
  background:var(--c-white);
  border:1px solid var(--c-ink-12);
  margin-bottom:12px;
  transition:border-color .25s var(--ease);
}
.acc[open]{ border-color:var(--c-lake); }
.acc summary{
  cursor:pointer;
  list-style:none;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:16px;
  padding:18px 22px;
  font-size:16px;
  font-weight:700;
  color:var(--c-ink);
}
.acc summary::-webkit-details-marker{ display:none; }
.acc summary::after{
  content:"＋";
  flex:none;
  font-family:var(--font-mono);
  font-size:20px;
  color:var(--c-lake);
  transition:transform .3s var(--ease);
}
.acc[open] summary::after{ content:"－"; }
.acc__body{
  padding:0 22px 22px;
  font-size:15px;
  line-height:1.9;
  color:var(--c-gray);
}

/* ---------- 站内检索 ---------- */
.search-box{
  display:flex;
  align-items:center;
  gap:10px;
  background:var(--c-white);
  border:2px solid var(--c-ink);
  padding:6px 6px 6px 18px;
  clip-path:polygon(0 0,calc(100% - 14px) 0,100% 14px,100% 100%,0 100%);
  transition:border-color .25s var(--ease);
}
.search-box:focus-within{ border-color:var(--c-lake); }
.search-box__input{
  flex:1;
  min-width:0;
  border:0;
  background:transparent;
  font-size:16px;
  color:var(--c-ink);
}
.search-box__input:focus{ outline:none; }
.search-box__input::placeholder{ color:var(--c-gray); opacity:.72; }
.search-box__btn{
  background:var(--c-sun);
  color:var(--c-ink);
  border:0;
  padding:12px 22px;
  font-size:14px;
  font-weight:800;
  cursor:pointer;
  white-space:nowrap;
  clip-path:polygon(0 0,calc(100% - 8px) 0,100% 8px,100% 100%,0 100%);
  transition:filter .25s var(--ease),transform .25s var(--ease);
}
.search-box__btn:hover{
  filter:brightness(1.05);
  transform:translateX(-2px);
}

/* ---------- 返回顶部 ---------- */
.to-top{
  position:fixed;
  right:22px;
  bottom:22px;
  z-index:900;
  width:48px;
  height:48px;
  display:grid;
  place-items:center;
  font-size:20px;
  color:var(--c-sun);
  background:var(--c-ink);
  border:1px solid var(--c-white-25);
  cursor:pointer;
  clip-path:polygon(0 0,100% 0,100% calc(100% - 10px),calc(100% - 10px) 100%,0 100%);
  opacity:0;
  visibility:hidden;
  transform:translateY(14px);
  transition:opacity .3s var(--ease),transform .3s var(--ease),visibility .3s,background-color .25s;
}
.to-top[data-visible]{ opacity:1; visibility:visible; transform:translateY(0); }
.to-top:hover{ background:var(--c-lake); color:#fff; }

/* ---------- 装饰辅助 ---------- */
.diagonal-lines{
  background-image:repeating-linear-gradient(-45deg,rgba(10,42,58,.05) 0 1px,transparent 1px 9px);
}
.diagonal-lines--light{
  background-image:repeating-linear-gradient(-45deg,rgba(255,255,255,.06) 0 1px,transparent 1px 9px);
}
.slant{
  display:block;
  height:22px;
  background:var(--c-sun);
  clip-path:polygon(0 55%,100% 0,100% 45%,0 100%);
}
.tape{
  display:block;
  height:8px;
  background:var(--c-sun);
  clip-path:polygon(0 0,100% 0,calc(100% - 8px) 100%,8px 100%);
}

/* ---------- 响应式 ---------- */
@media (max-width:1024px){
  .site-footer__inner{ grid-template-columns:1.4fr 1fr; }
  .site-footer__brand{ grid-column:1 / -1; }
  .grid--4{ grid-template-columns:repeat(2,1fr); }
  .grid--3{ grid-template-columns:repeat(2,1fr); }
  .span-6,.span-7,.span-8{ grid-column:span 6; }
}

@media (max-width:920px){
  :root{ --header-h:var(--header-h-m); }
  .site-header{ height:var(--header-h-m); }
  .site-header__inner{ height:var(--header-h-m); }

  .site-nav{
    position:fixed;
    inset:0;
    z-index:4;
    display:flex;
    flex-direction:column;
    justify-content:center;
    align-items:stretch;
    gap:0;
    padding:calc(var(--header-h-m) + 22px) var(--pad-x) 36px;
    background:
      radial-gradient(640px 320px at 88% 18%,rgba(0,211,167,.18),transparent 62%),
      linear-gradient(160deg,var(--c-ink) 0%,#061c28 100%);
    opacity:0;
    visibility:hidden;
    transform:translateY(-16px);
    transition:opacity .32s var(--ease),transform .32s var(--ease),visibility .32s;
    overflow-y:auto;
  }
  .site-nav::before{
    content:"LEJING";
    position:absolute;
    right:-24px;
    bottom:4vh;
    font-family:var(--font-mono);
    font-size:clamp(84px,22vw,190px);
    line-height:1;
    letter-spacing:-.04em;
    color:rgba(255,255,255,.035);
    pointer-events:none;
    white-space:nowrap;
  }
  .site-nav[data-open]{
    opacity:1;
    visibility:visible;
    transform:translateY(0);
  }

  .site-nav__list{
    width:100%;
    max-width:560px;
    margin-inline:auto;
    display:flex;
    flex-direction:column;
    gap:2px;
  }
  .site-nav__list a{
    display:flex;
    align-items:baseline;
    gap:14px;
    padding:15px 4px;
    font-size:clamp(22px,6vw,30px);
    font-weight:900;
    color:var(--c-white-85);
    border-bottom:1px solid var(--c-white-12);
    transition:color .25s var(--ease),transform .25s var(--ease);
  }
  .site-nav__list a::before{
    content:attr(data-index);
    font-family:var(--font-mono);
    font-size:12px;
    font-weight:500;
    letter-spacing:.04em;
    color:var(--c-sun);
  }
  .site-nav__list a:hover{ color:#fff; transform:translateX(4px); }
  .site-nav__list a[aria-current="page"]{ color:var(--c-sun); }

  .site-hotline{
    display:inline-flex;
    margin:32px auto 0;
    border-color:var(--c-white-25);
    background:rgba(255,255,255,.05);
  }

  .site-nav-toggle{ display:flex; }
  .site-nav-toggle__label{
    position:absolute;
    width:1px;
    height:1px;
    overflow:hidden;
    clip:rect(0 0 0 0);
  }

  .sec-head__note{ display:none; }
}

@media (max-width:640px){
  .site-footer__inner{ grid-template-columns:1fr; }
  .site-footer__brand{ grid-column:auto; }
  .grid--2,.grid--3,.grid--4{ grid-template-columns:1fr; }
  .span-2,.span-3,.span-4,.span-5,.span-6,.span-7,.span-8,.span-12{ grid-column:1 / -1; }
  .sec-head{ flex-wrap:wrap; }
  .sec-head__line{ order:10; flex-basis:100%; }
  .to-top{ right:14px; bottom:14px; }
}

/* ---------- 动效降级 ---------- */
@media (prefers-reduced-motion:reduce){
  html{ scroll-behavior:auto; }
  *,*::before,*::after{
    animation-duration:.01ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.01ms !important;
  }
  .ticker__track,
  .ticker:hover .ticker__track{ animation-play-state:paused !important; }
  .site-nav-toggle__bar,
  .site-nav-toggle[aria-expanded="true"] .site-nav-toggle__bar{
    transform:none;
    opacity:1;
    transition:none;
  }
}