/* ============================================================
   KAIYUN赛场 — /assets/site.css
   共享层：重置 / 变量 / 中文排版 / 页头 / 页脚 / 按钮 / 网格 / 组件
   ============================================================ */

/* ---------- 1. 重置 ---------- */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body,h1,h2,h3,h4,p,ul,ol,li,figure,blockquote{margin:0;padding:0}
ul,ol{list-style:none}
a{color:inherit;text-decoration:none}
button{font:inherit;color:inherit;background:none;border:0;padding:0;cursor:pointer}
img,svg{display:block;max-width:100%}
table{border-collapse:collapse;width:100%}

/* ---------- 2. 变量 ---------- */
:root{
  --ink:#071A16;
  --charcoal:#0B0F0E;
  --panel:#18332D;
  --paper:#F2F7F5;
  --silver:#B9C6C2;
  --cyan:#39F5D0;
  --orange:#FF7A1A;
  --deep:#10241F;
  --mist:#DDE8E4;

  --line:rgba(185,198,194,.18);
  --line-strong:rgba(185,198,194,.38);
  --line-cyan:rgba(57,245,208,.42);

  --font-sans:"Noto Sans SC","Source Han Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,-apple-system,"Segoe UI",sans-serif;
  --font-mono:"JetBrains Mono","Roboto Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;

  --wrap:1320px;
  --gutter:clamp(18px,4vw,56px);
  --space:clamp(32px,5.5vw,80px);
  --ease:160ms ease;
  --radius:2px;
}

/* ---------- 3. 基础与中文排版 ---------- */
body{
  background:var(--ink);
  color:var(--paper);
  font-family:var(--font-sans);
  font-size:16px;
  font-weight:400;
  line-height:1.75;
  letter-spacing:.01em;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
body::before{
  content:"";
  position:fixed;
  inset:0;
  z-index:0;
  pointer-events:none;
  background-image:
    repeating-linear-gradient(to right,rgba(185,198,194,.055) 0 1px,transparent 1px 96px),
    repeating-linear-gradient(to bottom,rgba(185,198,194,.038) 0 1px,transparent 1px 96px);
}
.site-header,.site-footer,main{position:relative;z-index:1}

h1,h2,h3,h4{font-weight:700;line-height:1.14;letter-spacing:-.01em}
p{max-width:70ch}
strong{font-weight:500;color:var(--paper)}
::selection{background:var(--cyan);color:#07120F}
:focus-visible{outline:2px solid var(--cyan);outline-offset:3px}

/* ---------- 4. 跳转链接 ---------- */
.skip-link{
  position:fixed;top:-120px;left:16px;z-index:200;
  padding:12px 20px;border-radius:var(--radius);
  background:var(--cyan);color:#07120F;
  font-size:14px;font-weight:700;letter-spacing:.04em;
  transition:top var(--ease);
}
.skip-link:focus,.skip-link:focus-visible{top:14px}

/* ---------- 5. 版式与容器 ---------- */
.container{width:100%;max-width:var(--wrap);margin-inline:auto;padding-inline:var(--gutter)}
.section{padding-block:var(--space);position:relative;z-index:1}
.section--tight{padding-block:clamp(22px,3.4vw,44px)}
.rule{height:1px;border:0;background:var(--line);margin:0}

.display{font-size:clamp(40px,7.2vw,96px);line-height:.94;font-weight:800;letter-spacing:-.03em}
.display--md{font-size:clamp(30px,4.6vw,64px);line-height:1.02;font-weight:800;letter-spacing:-.02em}
.heading-sm{font-size:clamp(20px,2.2vw,28px);font-weight:700;letter-spacing:-.01em;line-height:1.3}
.mono{font-family:var(--font-mono);font-variant-numeric:tabular-nums;letter-spacing:.02em}
.lede{max-width:68ch;color:var(--silver);font-size:16px;line-height:1.78}
.eyebrow{
  display:inline-flex;align-items:center;gap:10px;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.24em;
  text-transform:uppercase;color:var(--cyan);
}
.eyebrow::before{content:"";width:26px;height:1px;background:currentColor;flex:none}
.eyebrow--orange{color:var(--orange)}
.stack{display:grid;gap:16px}

/* ---------- 6. 网格 ---------- */
.grid{display:grid;gap:clamp(16px,2.4vw,32px)}
.grid--7-5{grid-template-columns:7fr 5fr}
.grid--5-7{grid-template-columns:5fr 7fr}
.grid--8-4{grid-template-columns:8fr 4fr}
.grid--4-8{grid-template-columns:4fr 8fr}
.grid--3{grid-template-columns:repeat(3,minmax(0,1fr))}
.grid--2{grid-template-columns:repeat(2,minmax(0,1fr))}
@media(max-width:960px){
  .grid--7-5,.grid--5-7,.grid--8-4,.grid--4-8,.grid--3{grid-template-columns:1fr}
}
@media(max-width:640px){
  .grid--2{grid-template-columns:1fr}
}

/* ---------- 7. 按钮 ---------- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:10px;
  padding:12px 22px;border:1px solid transparent;border-radius:var(--radius);
  font-size:14px;font-weight:500;letter-spacing:.06em;line-height:1.2;
  transition:background var(--ease),color var(--ease),border-color var(--ease),box-shadow var(--ease);
}
.btn--primary{background:var(--orange);border-color:var(--orange);color:#0A100E;font-weight:700}
.btn--primary:hover{background:#E96A0C;border-color:#FFB27A;color:#0A100E}
.btn--ghost{border-color:var(--line-strong);color:var(--paper);background:transparent}
.btn--ghost:hover{border-color:var(--cyan);color:var(--cyan)}
.btn--block{width:100%}

/* ---------- 8. 卡片 / 标签 / 面包屑 ---------- */
.card{
  position:relative;background:var(--panel);
  border:1px solid var(--line);border-radius:var(--radius);
  padding:clamp(18px,2.2vw,28px);
  transition:border-color var(--ease),background var(--ease);
}
.card:hover{border-color:var(--line-cyan)}
.card:focus-within{outline:2px solid var(--cyan);outline-offset:2px}
.card--flat{background:transparent}
.card--accent{
  border-color:var(--line-cyan);
  background:linear-gradient(165deg,rgba(57,245,208,.07),transparent 58%),var(--panel);
}
.card-title{font-size:clamp(18px,1.9vw,24px);font-weight:700;line-height:1.32}
.card-meta{
  font-family:var(--font-mono);font-size:11px;letter-spacing:.18em;
  text-transform:uppercase;color:var(--silver);
}
.card-text{margin-top:10px;color:var(--silver);font-size:14.5px;line-height:1.75}

.tag{
  display:inline-flex;align-items:center;gap:6px;
  padding:3px 9px;border:1px solid var(--line-cyan);border-radius:1px;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.14em;
  text-transform:uppercase;line-height:1.6;color:var(--cyan);
}
.tag--orange{border-color:rgba(255,122,26,.45);color:var(--orange)}
.tag--muted{border-color:var(--line);color:var(--silver)}

.breadcrumb{padding-block:18px}
.breadcrumb-list{
  display:flex;flex-wrap:wrap;align-items:center;gap:8px;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.14em;color:var(--silver);
}
.breadcrumb-item{display:inline-flex;align-items:center;gap:8px}
.breadcrumb-item + .breadcrumb-item::before{content:"/";color:rgba(185,198,194,.45)}
.breadcrumb-link{color:var(--silver);transition:color var(--ease)}
.breadcrumb-link:hover{color:var(--cyan)}
.breadcrumb-item[aria-current="page"]{color:var(--paper)}

/* ---------- 9. 图片容器（供页面阶段放置占位图） ---------- */
.media-frame{
  position:relative;display:block;overflow:hidden;
  border:1px solid var(--line);border-radius:var(--radius);
  background:linear-gradient(155deg,#0E2A24 0%,#071A16 58%,#0B1A17 100%);
  aspect-ratio:16/9;
}
.media-frame::after{
  content:"";position:absolute;inset:10px;
  border:1px solid rgba(57,245,208,.16);pointer-events:none;
}
.media-frame img{width:100%;height:100%;object-fit:cover;filter:saturate(.92) contrast(1.02)}
.media-frame--wide{aspect-ratio:21/9}
.media-frame--square{aspect-ratio:1/1}
.media-frame--tall{aspect-ratio:3/4}
.media-caption{margin-top:10px;font-family:var(--font-mono);font-size:11px;letter-spacing:.12em;color:var(--silver)}

/* ---------- 10. 横向主题带 ---------- */
.band{
  background:var(--deep);border-block:1px solid var(--line);
  padding-block:14px;overflow:hidden;
}
.band-inner{
  display:flex;align-items:center;gap:clamp(16px,3vw,40px);
  width:100%;max-width:var(--wrap);margin-inline:auto;padding-inline:var(--gutter);
}
.band-label{
  font-family:var(--font-mono);font-size:11px;letter-spacing:.2em;
  text-transform:uppercase;color:var(--orange);white-space:nowrap;
}
.band-text{font-size:13.5px;letter-spacing:.04em;color:var(--silver)}

/* ---------- 11. 页头 ---------- */
.site-header{
  position:sticky;top:0;z-index:80;
  background:var(--charcoal);
  border-bottom:1px solid var(--line);
}
.header-rail{background:#080D0C;border-bottom:1px solid var(--line)}
.header-rail-inner{
  display:flex;align-items:center;justify-content:space-between;gap:16px;
  width:100%;max-width:var(--wrap);margin-inline:auto;
  padding:7px var(--gutter);
}
.rail-item{
  display:inline-flex;align-items:center;gap:8px;
  font-family:var(--font-mono);font-size:10.5px;letter-spacing:.18em;
  text-transform:uppercase;color:var(--silver);white-space:nowrap;
}
.rail-item--mono{color:var(--cyan)}
.rail-dot{
  width:6px;height:6px;flex:none;background:var(--orange);
  box-shadow:0 0 0 1px rgba(255,122,26,.35);
}

.header-inner{
  position:relative;
  display:flex;align-items:center;justify-content:space-between;gap:20px;
  width:100%;max-width:var(--wrap);margin-inline:auto;
  padding:14px var(--gutter);
}

.brand{display:inline-flex;align-items:center;gap:12px;flex:none}
.brand-mark{
  position:relative;width:16px;height:16px;flex:none;
  border:1px solid var(--cyan);
  transition:border-color var(--ease);
}
.brand-mark::after{
  content:"";position:absolute;inset:4px;background:var(--orange);
  transition:transform var(--ease),background var(--ease);
}
.brand:hover .brand-mark{border-color:var(--orange)}
.brand:hover .brand-mark::after{transform:scale(.55);background:var(--cyan)}
.brand-text{display:block}
.brand-name{display:block;font-size:17px;font-weight:700;letter-spacing:.02em;line-height:1.2}
.brand-note{
  display:block;font-family:var(--font-mono);font-size:10px;
  letter-spacing:.26em;color:var(--silver);line-height:1.7;
}

.nav-toggle{
  display:none;align-items:center;gap:10px;
  padding:9px 14px;border:1px solid var(--line-strong);border-radius:var(--radius);
  color:var(--paper);font-family:var(--font-mono);
  font-size:11px;letter-spacing:.18em;text-transform:uppercase;
  transition:border-color var(--ease),color var(--ease);
}
.nav-toggle:hover{border-color:var(--cyan);color:var(--cyan)}
.nav-toggle-icon{display:grid;gap:3px;width:16px}
.nav-toggle-line{display:block;height:1px;background:currentColor;transition:transform var(--ease),opacity var(--ease)}
.nav-toggle[aria-expanded="true"] .nav-toggle-line:nth-child(1){transform:translateY(4px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] .nav-toggle-line:nth-child(2){opacity:0}
.nav-toggle[aria-expanded="true"] .nav-toggle-line:nth-child(3){transform:translateY(-4px) rotate(-45deg)}

.site-nav{display:flex;align-items:center;gap:clamp(14px,2vw,28px)}
.nav-list{display:flex;align-items:stretch}
.nav-item{display:flex}
.nav-item + .nav-item{border-left:1px solid var(--line)}
.nav-link{
  position:relative;display:block;padding:8px 14px;
  font-size:14px;letter-spacing:.04em;color:var(--paper);
  transition:color var(--ease);
}
.nav-index{
  display:block;font-family:var(--font-mono);font-size:10px;
  letter-spacing:.2em;line-height:1.7;color:var(--silver);
  transition:color var(--ease);
}
.nav-link::after{
  content:"";position:absolute;left:14px;right:14px;bottom:2px;height:1px;
  background:var(--cyan);transform:scaleX(0);transform-origin:left center;
  transition:transform var(--ease);
}
.nav-link:hover{color:var(--cyan)}
.nav-link:hover .nav-index{color:var(--cyan)}
.nav-link:hover::after,.nav-link:focus-visible::after{transform:scaleX(1)}
.nav-link[aria-current="page"]{color:var(--cyan)}
.nav-link[aria-current="page"] .nav-index{color:var(--orange)}
.nav-link[aria-current="page"]::after{transform:scaleX(1)}

.nav-cta{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  padding:10px 16px;border:1px solid var(--orange);border-radius:var(--radius);
  font-size:13px;font-weight:500;letter-spacing:.08em;color:var(--orange);
  white-space:nowrap;
  transition:background var(--ease),color var(--ease),border-color var(--ease);
}
.nav-cta:hover{background:var(--orange);color:#0A100E}

.header-progress{
  position:absolute;left:0;right:0;bottom:-1px;height:2px;
  background:transparent;pointer-events:none;
}
.header-progress-bar{
  display:block;width:100%;height:100%;
  background:linear-gradient(90deg,var(--cyan),var(--orange));
  transform:scaleX(0);transform-origin:left center;
  transition:transform 120ms linear;
}

/* ---------- 12. 页脚 ---------- */
.site-footer{background:var(--charcoal);border-top:1px solid var(--line);color:var(--paper)}
.footer-top{background:var(--deep);border-bottom:1px solid var(--line)}
.footer-top-inner{
  display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:16px;
  width:100%;max-width:var(--wrap);margin-inline:auto;
  padding:22px var(--gutter);
}
.footer-lede{
  font-size:clamp(17px,2.1vw,24px);font-weight:700;
  letter-spacing:-.01em;line-height:1.35;max-width:26ch;
}
.footer-cta{
  display:inline-flex;align-items:center;gap:10px;
  padding:11px 18px;border:1px solid var(--line-strong);border-radius:var(--radius);
  font-family:var(--font-mono);font-size:12px;letter-spacing:.14em;color:var(--paper);
  transition:border-color var(--ease),color var(--ease),background var(--ease);
}
.footer-cta:hover{border-color:var(--cyan);color:var(--cyan);background:rgba(57,245,208,.06)}

.footer-grid{
  display:grid;
  grid-template-columns:1.5fr .9fr .9fr .9fr 1.7fr;
  gap:clamp(22px,3vw,40px) clamp(18px,2.4vw,32px);
  width:100%;max-width:var(--wrap);margin-inline:auto;
  padding:clamp(34px,5vw,64px) var(--gutter) clamp(26px,3.4vw,44px);
}
.footer-brand{display:flex;flex-direction:column;gap:12px}
.footer-brand-link{display:inline-flex;align-items:center;gap:10px}
.footer-mark{position:relative;width:13px;height:13px;flex:none;border:1px solid var(--cyan)}
.footer-mark::after{content:"";position:absolute;inset:3px;background:var(--orange)}
.footer-name{font-size:16px;font-weight:700;letter-spacing:.02em}
.footer-tag{font-family:var(--font-mono);font-size:11px;letter-spacing:.1em;line-height:1.9;color:var(--silver);max-width:30ch}
.footer-note{font-size:12.5px;line-height:1.7;color:rgba(185,198,194,.72);max-width:28ch}

.footer-col{display:block}
.footer-col-title{
  margin-bottom:14px;
  font-family:var(--font-mono);font-size:11px;font-weight:500;
  letter-spacing:.22em;text-transform:uppercase;color:var(--cyan);
}
.footer-list{display:grid;gap:9px}
.footer-link{
  position:relative;display:inline-block;
  font-size:14px;color:var(--silver);
  transition:color var(--ease);
}
.footer-link::after{
  content:"";position:absolute;left:0;right:0;bottom:-1px;height:1px;
  background:var(--cyan);transform:scaleX(0);transform-origin:left center;
  transition:transform var(--ease);
}
.footer-link:hover{color:var(--cyan)}
.footer-link:hover::after{transform:scaleX(1)}
.footer-link--inline{font-family:var(--font-mono);font-size:12px;letter-spacing:.1em}

.footer-col--contact{display:block}
.contact-row{
  display:grid;grid-template-columns:46px minmax(0,1fr);gap:10px;
  padding:8px 0;border-bottom:1px solid rgba(185,198,194,.1);
}
.contact-row:first-of-type{border-top:1px solid rgba(185,198,194,.1)}
.contact-label{
  font-family:var(--font-mono);font-size:11px;letter-spacing:.14em;
  text-transform:uppercase;color:var(--silver);
}
.contact-value{font-size:13.5px;line-height:1.7;color:var(--paper);word-break:break-word}
.contact-note{margin-top:12px;font-size:12px;line-height:1.75;color:rgba(185,198,194,.7);max-width:38ch}

.footer-bottom{border-top:1px solid var(--line)}
.footer-bottom-inner{
  display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:12px 24px;
  width:100%;max-width:var(--wrap);margin-inline:auto;
  padding:18px var(--gutter) 26px;
}
.footer-legal{font-family:var(--font-mono);font-size:11.5px;letter-spacing:.1em;color:var(--silver)}
.footer-meta{
  display:inline-flex;align-items:center;gap:8px;
  font-family:var(--font-mono);font-size:11.5px;letter-spacing:.1em;
  color:rgba(185,198,194,.7);
}
.footer-meta--links{gap:8px}
.footer-sep{color:rgba(185,198,194,.4)}

/* ---------- 13. 显现协议 ---------- */
.js [data-reveal]{opacity:0;transform:translateY(14px);transition:opacity 480ms ease,transform 480ms ease}
.js [data-reveal].is-visible{opacity:1;transform:none}

/* ---------- 14. 响应式 ---------- */
@media(max-width:1100px){
  .footer-grid{grid-template-columns:repeat(3,minmax(0,1fr))}
  .footer-col--contact{grid-column:1 / -1}
}
@media(max-width:900px){
  .nav-toggle{display:inline-flex}
  .site-nav{
    position:absolute;top:100%;left:0;right:0;
    display:none;flex-direction:column;align-items:stretch;gap:0;
    background:var(--charcoal);
    border-top:1px solid var(--line);border-bottom:1px solid var(--line);
    padding:6px var(--gutter) 20px;
    max-height:calc(100dvh - 110px);overflow-y:auto;
    box-shadow:0 26px 52px rgba(0,0,0,.55);
  }
  .site-nav[data-open="true"]{display:flex}
  .nav-list{flex-direction:column}
  .nav-item{display:block;border-left:0;border-bottom:1px solid var(--line)}
  .nav-link{display:flex;align-items:baseline;gap:14px;padding:15px 2px;font-size:16px}
  .nav-index{font-size:11px}
  .nav-link::after{left:2px;right:2px;bottom:6px}
  .nav-cta{margin-top:16px;width:100%;padding:14px 18px;font-size:14px}
  .header-inner{padding-block:12px}
}
@media(max-width:760px){
  .footer-grid{grid-template-columns:1fr 1fr}
  .footer-brand{grid-column:1 / -1}
  .footer-col--contact{grid-column:1 / -1}
  .footer-top-inner{flex-direction:column;align-items:flex-start}
  .footer-lede{max-width:none}
}
@media(max-width:640px){
  .rail-item:nth-child(2){display:none}
  .brand-name{font-size:16px}
  .footer-grid{grid-template-columns:1fr}
  .footer-bottom-inner{flex-direction:column;align-items:flex-start;gap:10px}
  .display{letter-spacing:-.02em}
}
@media(max-width:400px){
  .brand-note{display:none}
  .nav-toggle-text{display:none}
}

/* ---------- 15. 降低动效 ---------- */
@media (prefers-reduced-motion: reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{
    animation-duration:.01ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.01ms !important;
    scroll-behavior:auto !important;
  }
  .js [data-reveal]{opacity:1;transform:none}
  .header-progress-bar{transition:none}
}