/* =========================================================
   sideline-zhongou.com.cn /assets/site.css
   球场深底 · 玻璃面板 · 信号绿 + 琥珀橙
   ========================================================= */

/* ---------- 1. Reset ---------- */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-padding-top:calc(var(--header-h) + 16px)}
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,canvas{display:block;max-width:100%;height:auto}
button,input,select,textarea{font:inherit;color:inherit}
button{background:none;border:0;cursor:pointer}
a{color:inherit;text-decoration:none}
table{border-collapse:collapse;width:100%}

/* ---------- 2. Tokens ---------- */
:root{
  --pitch:#0A1216;
  --stand:#0F1E1A;
  --glass:#16262D;
  --glass-soft:rgba(22,38,45,.62);
  --glass-strong:rgba(22,38,45,.9);
  --signal:#00E676;
  --signal-hi:#39FFB0;
  --amber:#FF9100;
  --white:#F2F6F7;
  --grey:#A8B4BA;
  --steel:#5F7178;
  --shadow-green:#06231A;
  --paper:#EDF1F1;
  --ink:#12201F;
  --line:rgba(95,113,120,.35);
  --line-soft:rgba(95,113,120,.2);
  --signal-line:rgba(0,230,118,.35);
  --amber-line:rgba(255,145,0,.35);

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

  --maxw:1440px;
  --gutter:clamp(20px,4vw,72px);
  --header-h:66px;
  --radius:3px;
  --ease:cubic-bezier(.22,.61,.36,1);
}

/* ---------- 3. Base ---------- */
html{scroll-behavior:smooth}
body{
  min-height:100vh;
  background-color:var(--pitch);
  background-image:
    radial-gradient(900px 520px at 88% -6%, rgba(0,230,118,.10), transparent 62%),
    radial-gradient(720px 420px at 2% 6%, rgba(255,145,0,.07), transparent 64%);
  background-repeat:no-repeat;
  color:var(--white);
  font-family:var(--font-body);
  font-size:17px;
  line-height:1.75;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
h1,h2,h3,h4,h5{font-family:var(--font-title);font-weight:600;line-height:1.16;letter-spacing:.004em}
h1{font-size:clamp(36px,5.2vw,72px)}
h2{font-size:clamp(26px,3.2vw,40px)}
h3{font-size:clamp(19px,2vw,24px)}
h4{font-size:18px}
strong{font-weight:600;color:var(--white)}
::selection{background:var(--signal);color:#04170F}
#main-content{display:block;min-height:1px}

/* 正文容器：段落宽度 ≤38 汉字 */
.prose{max-width:46em}
.prose p{max-width:38em;margin-block:0 1.1em;color:var(--grey);font-size:17px}
.prose p:last-child{margin-bottom:0}
.prose h2,.prose h3{margin-block:2em .6em;color:var(--white)}
.prose h2:first-child,.prose h3:first-child{margin-top:0}
.prose ul,.prose ol{margin-block:0 1.2em;padding-left:1.2em;list-style:disc;color:var(--grey);max-width:38em}
.prose li{margin-block:.35em}
.prose strong{color:var(--white)}
.prose a{color:var(--signal-hi);border-bottom:1px solid var(--signal-line)}
.prose a:hover{color:var(--signal)}

/* ---------- 4. Utils ---------- */
.wrap{width:100%;max-width:var(--maxw);margin-inline:auto;padding-inline:var(--gutter)}
.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0}
.coord{display:inline-block;font-family:var(--font-mono);font-size:12px;letter-spacing:.16em;text-transform:uppercase;color:var(--steel)}
.section{padding-block:clamp(48px,7vw,104px)}
.section--tight{padding-block:clamp(30px,4vw,56px)}
.section__head{display:flex;flex-wrap:wrap;align-items:flex-end;justify-content:space-between;gap:16px 32px;padding-bottom:14px;margin-bottom:clamp(22px,3vw,38px);border-bottom:1px solid var(--line)}
.section__title{font-size:clamp(24px,2.6vw,34px);color:var(--white)}
.section__lead{max-width:34em;color:var(--grey);font-size:15px}

/* ---------- 5. Skip link ---------- */
.skip-link{position:absolute;left:16px;top:-72px;z-index:120;padding:10px 18px;background:var(--signal);color:#04170F;font-weight:600;font-size:14px;border-radius:0 0 var(--radius) var(--radius);transition:top .18s var(--ease)}
.skip-link:focus{top:0}

/* ---------- 6. Header ---------- */
.site-header{position:sticky;top:0;z-index:80;background:transparent;border-bottom:1px solid transparent;transition:background .3s var(--ease),border-color .3s var(--ease),backdrop-filter .3s var(--ease)}
.site-header[data-stuck]{background:rgba(10,18,22,.74);-webkit-backdrop-filter:blur(16px) saturate(150%);backdrop-filter:blur(16px) saturate(150%);border-bottom-color:var(--line)}
.header-inner{display:flex;align-items:center;gap:clamp(12px,1.6vw,26px);width:100%;max-width:var(--maxw);min-height:var(--header-h);margin-inline:auto;padding:10px var(--gutter)}

.brand{display:flex;align-items:center;gap:11px;margin-right:auto;color:var(--white)}
.brand__mark{position:relative;flex:0 0 auto;width:12px;height:26px;background:var(--signal);border-radius:1px;box-shadow:0 0 0 1px rgba(0,230,118,.25)}
.brand__mark::after{content:"";position:absolute;left:16px;top:50%;width:14px;height:2px;background:var(--amber);transform:translateY(-50%)}
.brand__text{display:flex;flex-direction:column;line-height:1.15}
.brand__name{font-family:var(--font-title);font-weight:600;font-size:20px;letter-spacing:.02em}
.brand__tag{font-family:var(--font-mono);font-size:11px;letter-spacing:.18em;text-transform:uppercase;color:var(--steel)}

.header-clock{display:flex;align-items:baseline;gap:8px;flex:0 0 auto;padding:5px 11px;border:1px solid var(--amber-line);border-radius:var(--radius);background:rgba(255,145,0,.08);font-family:var(--font-mono);font-size:13px;line-height:1.2;color:var(--amber)}
.header-clock__label{font-size:11px;letter-spacing:.16em;color:var(--grey)}
.header-clock__value{font-variant-numeric:tabular-nums;letter-spacing:.06em;min-width:9ch;text-align:right}

.site-nav{display:flex;align-items:center;gap:clamp(12px,1.5vw,24px)}
.nav-list{display:flex;align-items:center;gap:clamp(10px,1.5vw,22px)}
.nav-list__item{flex:0 0 auto}
.nav-link{position:relative;display:inline-block;padding:8px 2px;font-size:15px;color:var(--grey);transition:color .18s var(--ease)}
.nav-link::after{content:"";position:absolute;left:0;right:0;bottom:2px;height:2px;background:var(--signal);transform:scaleX(0);transform-origin:left;transition:transform .18s var(--ease)}
.nav-link:hover{color:var(--white)}
.nav-link:hover::after{transform:scaleX(1)}
.nav-link[aria-current="page"]{color:var(--white)}
.nav-link[aria-current="page"]::after{transform:scaleX(1)}

.header-cta{flex:0 0 auto;padding:9px 16px;font-size:14px}

.nav-toggle{display:none;align-items:center;gap:10px;padding:9px 13px;border:1px solid var(--line);border-radius:var(--radius);color:var(--white);font-size:13px;letter-spacing:.1em;transition:border-color .18s var(--ease),color .18s var(--ease)}
.nav-toggle:hover{border-color:var(--signal);color:var(--signal-hi)}
.nav-toggle__bars{position:relative;display:block;width:18px;height:2px;background:var(--white);transition:background .18s var(--ease)}
.nav-toggle__bars::before,.nav-toggle__bars::after{content:"";position:absolute;left:0;width:18px;height:2px;background:var(--white);transition:transform .2s var(--ease),top .2s var(--ease),background .2s var(--ease)}
.nav-toggle__bars::before{top:-6px}
.nav-toggle__bars::after{top:6px}
.nav-toggle__label{font-family:var(--font-mono);text-transform:uppercase}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars{background:transparent}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::before{top:0;background:var(--signal);transform:rotate(45deg)}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::after{top:0;background:var(--signal);transform:rotate(-45deg)}

.scroll-progress{position:absolute;left:0;right:0;bottom:-1px;height:2px;background:rgba(95,113,120,.18);overflow:hidden}
.scroll-progress__bar{display:block;height:100%;width:100%;transform:scaleX(0);transform-origin:left;background:linear-gradient(90deg,var(--signal),var(--signal-hi) 60%,var(--amber))}

/* ---------- 7. Buttons ---------- */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:12px 22px;border:1px solid transparent;border-radius:var(--radius);font-size:15px;font-weight:600;letter-spacing:.02em;line-height:1.2;transition:background .18s var(--ease),color .18s var(--ease),border-color .18s var(--ease),transform .18s var(--ease)}
.btn--signal{background:var(--signal);color:#04170F}
.btn--signal:hover{background:var(--signal-hi);transform:translateY(-1px)}
.btn--ghost{border-color:var(--line);color:var(--white)}
.btn--ghost:hover{border-color:var(--signal);color:var(--signal-hi)}
.btn--amber{border-color:var(--amber-line);color:var(--amber);background:rgba(255,145,0,.06)}
.btn--amber:hover{background:rgba(255,145,0,.14)}

/* ---------- 8. Breadcrumb ---------- */
.breadcrumb{padding-block:16px;border-bottom:1px solid var(--line-soft)}
.breadcrumb__list{display:flex;flex-wrap:wrap;align-items:center;gap:9px;font-family:var(--font-mono);font-size:12px;letter-spacing:.14em;text-transform:uppercase;color:var(--steel)}
.breadcrumb__item{display:inline-flex;align-items:center;gap:9px}
.breadcrumb__link{color:var(--grey);transition:color .18s var(--ease)}
.breadcrumb__link:hover{color:var(--signal-hi)}
.breadcrumb__sep{color:var(--steel)}
.breadcrumb__current{color:var(--white)}

/* ---------- 9. Grid & layout ---------- */
.grid{display:grid;gap:clamp(16px,2vw,28px)}
.grid--2{grid-template-columns:repeat(2,minmax(0,1fr))}
.grid--3{grid-template-columns:repeat(3,minmax(0,1fr))}
.layout-asym{display:grid;grid-template-columns:4fr 5fr 3fr;gap:clamp(16px,2vw,28px);align-items:start}
.col--rail{min-width:0}
.col--sticky{position:sticky;top:calc(var(--header-h) + 18px)}

/* ---------- 10. Panels ---------- */
.panel{padding:clamp(16px,2vw,26px);background:var(--stand);border:1px solid var(--line-soft);border-radius:var(--radius)}
.panel--glass{background:var(--glass-soft);border-color:var(--signal-line);-webkit-backdrop-filter:blur(14px);backdrop-filter:blur(14px);box-shadow:0 24px 60px rgba(6,35,26,.55)}
.panel--signal{border-color:var(--signal-line);background:linear-gradient(160deg,rgba(0,230,118,.08),rgba(15,30,26,.9) 55%)}
.paper-panel{background:var(--paper);color:var(--ink);border-radius:var(--radius);padding:clamp(22px,3.4vw,56px)}
.paper-panel h1,.paper-panel h2,.paper-panel h3{color:var(--ink)}
.paper-panel .prose p,.paper-panel .prose li{color:#3A4A4C}
.paper-panel .prose a{color:#0B7A46;border-bottom-color:rgba(11,122,70,.4)}
.paper-panel .coord{color:#6C7C7E}

/* ---------- 11. Badges & chips ---------- */
.badge{display:inline-flex;align-items:center;gap:6px;padding:4px 9px;border:1px solid currentColor;border-radius:2px;font-family:var(--font-mono);font-size:11px;letter-spacing:.16em;text-transform:uppercase;line-height:1.4}
.badge--live{color:var(--signal)}
.badge--amber{color:var(--amber)}
.dot{display:inline-block;width:7px;height:7px;border-radius:50%;background:var(--signal);animation:pulse 2s infinite}
@keyframes pulse{0%{box-shadow:0 0 0 0 rgba(0,230,118,.55)}70%{box-shadow:0 0 0 9px rgba(0,230,118,0)}100%{box-shadow:0 0 0 0 rgba(0,230,118,0)}}
.chip-row{display:flex;flex-wrap:wrap;gap:8px}
.chip{display:inline-flex;align-items:center;gap:6px;padding:6px 14px;border:1px solid var(--line);border-radius:99px;font-size:13px;color:var(--grey);cursor:pointer;transition:border-color .18s var(--ease),color .18s var(--ease),background .18s var(--ease)}
.chip:hover{border-color:var(--signal);color:var(--white)}
.chip[aria-pressed="true"]{border-color:var(--signal);color:var(--signal);background:rgba(0,230,118,.08)}

/* ---------- 12. Index list ---------- */
.index-list{display:flex;flex-direction:column}
.index-row{display:grid;grid-template-columns:56px minmax(0,1fr) auto;gap:8px 18px;align-items:baseline;padding:18px 0;border-bottom:1px solid var(--line-soft);transition:border-color .18s var(--ease)}
.index-row:hover{border-bottom-color:rgba(0,230,118,.6)}
.index-row__num{font-family:var(--font-mono);font-size:13px;letter-spacing:.1em;color:var(--signal)}
.index-row__title{font-family:var(--font-title);font-size:19px;color:var(--white)}
.index-row__desc{grid-column:2 / 3;color:var(--grey);font-size:14px;max-width:40em}
.index-row__meta{grid-row:1 / 2;grid-column:3 / 4;font-family:var(--font-mono);font-size:12px;letter-spacing:.1em;color:var(--steel);text-align:right;white-space:nowrap}

/* ---------- 13. Stats & TOC ---------- */
.stat-rail{display:flex;flex-direction:column;gap:14px}
.stat{display:flex;flex-direction:column;gap:4px;padding-block:12px;border-top:1px solid var(--line-soft)}
.stat:first-child{border-top:1px solid var(--line)}
.stat__label{font-family:var(--font-mono);font-size:12px;letter-spacing:.16em;text-transform:uppercase;color:var(--steel)}
.stat__value{font-family:var(--font-mono);font-variant-numeric:tabular-nums;font-size:clamp(34px,4.4vw,64px);line-height:1;color:var(--white)}
.stat__value--signal{color:var(--signal)}
.stat__value--amber{color:var(--amber)}
.stat__note{font-size:13px;color:var(--grey)}
.toc{display:flex;flex-direction:column;gap:2px}
.toc__link{display:flex;align-items:baseline;gap:10px;padding:8px 0 8px 12px;border-left:2px solid transparent;font-size:14px;color:var(--grey);transition:color .18s var(--ease),border-color .18s var(--ease)}
.toc__link:hover{color:var(--white)}
.toc__link[data-active]{color:var(--signal);border-left-color:var(--signal)}
.toc__index{font-family:var(--font-mono);font-size:11px;letter-spacing:.14em;color:var(--steel)}
.toc__link[data-active] .toc__index{color:var(--signal)}

/* ---------- 14. Media ---------- */
.media{position:relative;overflow:hidden;width:100%;aspect-ratio:16 / 9;border:1px solid var(--line-soft);border-radius:var(--radius);background:linear-gradient(145deg,var(--glass) 0%,var(--stand) 58%,var(--shadow-green) 100%)}
.media--wide{aspect-ratio:21 / 9}
.media--tall{aspect-ratio:4 / 5}
.media img{width:100%;height:100%;object-fit:cover}
.media__cap{position:absolute;left:0;right:0;bottom:0;padding:14px 16px;font-family:var(--font-mono);font-size:12px;letter-spacing:.1em;color:var(--white);background:linear-gradient(180deg,rgba(6,35,26,0),rgba(6,35,26,.9))}
.media__tag{position:absolute;top:12px;left:12px;padding:4px 9px;border:1px solid var(--signal-line);border-radius:2px;background:rgba(6,35,26,.72);font-family:var(--font-mono);font-size:11px;letter-spacing:.14em;color:var(--signal);text-transform:uppercase}
.figure{display:flex;flex-direction:column;gap:10px}
.figure__cap{font-family:var(--font-mono);font-size:12px;letter-spacing:.1em;color:var(--steel)}

/* ---------- 15. Footer ---------- */
.site-footer{position:relative;margin-top:clamp(56px,8vw,120px);background:var(--stand);border-top:1px solid var(--line)}
.site-footer::before{content:"";position:absolute;top:0;left:0;width:min(300px,44vw);height:2px;background:linear-gradient(90deg,var(--signal),rgba(0,230,118,0))}
.footer-inner{width:100%;max-width:var(--maxw);margin-inline:auto;padding:clamp(30px,4vw,62px) var(--gutter) clamp(22px,3vw,34px)}
.footer-block{display:grid;grid-template-columns:minmax(80px,140px) minmax(0,1fr);gap:12px clamp(14px,2vw,32px);padding-block:clamp(16px,2.4vw,26px);border-top:1px solid var(--line-soft)}
.footer-block:first-child{padding-top:0;border-top:0}
.footer-block--brand{padding-bottom:clamp(20px,2.6vw,30px)}
.footer-coord{font-family:var(--font-mono);font-size:12px;letter-spacing:.16em;text-transform:uppercase;color:var(--steel)}
.footer-block__body{min-width:0}
.footer-brand{font-family:var(--font-title);font-weight:600;font-size:clamp(24px,2.6vw,32px);line-height:1.2;color:var(--white)}
.footer-line{margin-top:6px;max-width:34em;font-size:15px;color:var(--grey)}
.footer-list{display:flex;flex-wrap:wrap;gap:10px 26px}
.footer-list--inline{gap:10px 22px}
.footer-link{font-size:15px;color:var(--grey);transition:color .18s var(--ease)}
.footer-link:hover{color:var(--signal-hi)}
.footer-link--inline{color:var(--signal)}
.footer-link--inline:hover{color:var(--signal-hi)}
.footer-contact{display:grid;gap:8px}
.footer-contact li{display:flex;flex-wrap:wrap;gap:6px 14px;font-size:15px}
.footer-contact__k{min-width:52px;font-family:var(--font-mono);font-size:12px;letter-spacing:.14em;text-transform:uppercase;line-height:1.9;color:var(--steel)}
.footer-contact__v{color:var(--white)}
.footer-note{margin-top:12px;max-width:46em;font-size:13px;color:var(--grey)}
.footer-legal{margin-top:14px;font-family:var(--font-mono);font-size:12px;letter-spacing:.08em;color:var(--steel)}

/* ---------- 16. To top / reveal ---------- */
.to-top{position:fixed;right:clamp(16px,3vw,36px);bottom:clamp(16px,3vw,32px);z-index:90;display:inline-flex;align-items:center;justify-content:center;width:46px;height:46px;border:1px solid var(--line);border-radius:50%;background:var(--glass-strong);-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);color:var(--white);opacity:0;visibility:hidden;transform:translateY(10px);transition:opacity .24s var(--ease),transform .24s var(--ease),border-color .24s var(--ease),color .24s var(--ease),visibility .24s}
.to-top[data-visible]{opacity:1;visibility:visible;transform:none}
.to-top:hover{border-color:var(--signal);color:var(--signal)}
.to-top__arrow{font-size:16px;line-height:1}
html.js [data-reveal]{opacity:0;transform:translateY(14px);transition:opacity .5s var(--ease),transform .5s var(--ease)}
html.js [data-reveal].is-inview{opacity:1;transform:none}

/* ---------- 17. Focus ---------- */
:focus-visible{outline:2px solid var(--signal);outline-offset:2px;border-radius:2px}
a:focus:not(:focus-visible),button:focus:not(:focus-visible){outline:none}

/* ---------- 18. Responsive ---------- */
@media (max-width:1280px){
  .header-clock{display:none}
}
@media (max-width:1180px){
  .brand__tag{display:none}
}
@media (max-width:1080px){
  .nav-toggle{display:inline-flex;margin-left:auto}
  .site-nav{
    position:fixed;top:var(--header-h);left:0;right:0;z-index:75;
    display:flex;flex-direction:column;align-items:stretch;gap:0;
    padding:16px var(--gutter) 26px;
    background:rgba(10,18,22,.97);
    -webkit-backdrop-filter:blur(18px);backdrop-filter:blur(18px);
    border-top:1px solid var(--line-soft);
    border-bottom:1px solid var(--signal-line);
    box-shadow:0 28px 60px rgba(6,35,26,.65);
    max-height:calc(100vh - var(--header-h));overflow-y:auto;
    opacity:0;visibility:hidden;transform:translateY(-10px);
    transition:opacity .22s var(--ease),transform .22s var(--ease),visibility .22s var(--ease);
  }
  .site-nav[data-open]{opacity:1;visibility:visible;transform:none}
  .nav-list{flex-direction:column;align-items:stretch;gap:0}
  .nav-list__item{border-bottom:1px solid var(--line-soft)}
  .nav-link{display:block;padding:14px 2px;font-size:17px;color:var(--white)}
  .nav-link::after{display:none}
  .nav-link[aria-current="page"]{color:var(--signal)}
  .header-cta{width:100%;margin-top:18px}
  .layout-asym{grid-template-columns:6fr 6fr}
  .col--rail{grid-column:1 / -1}
  .col--sticky{position:static}
}
@media (max-width:760px){
  body{font-size:16px}
  .grid--2,.grid--3{grid-template-columns:minmax(0,1fr)}
  .layout-asym{grid-template-columns:minmax(0,1fr)}
  .index-row{grid-template-columns:42px minmax(0,1fr)}
  .index-row__meta{grid-row:3 / 4;grid-column:2 / 3;text-align:left}
  .footer-block{grid-template-columns:minmax(0,1fr);gap:8px}
  .footer-contact li{flex-direction:column;gap:0}
  .section__head{flex-direction:column;align-items:flex-start}
}

/* ---------- 19. Reduced motion ---------- */
@media (prefers-reduced-motion: reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{animation-duration:.001ms !important;animation-iteration-count:1 !important;transition-duration:.001ms !important}
  html.js [data-reveal],html.js [data-reveal].is-inview{opacity:1;transform:none}
  .btn--signal:hover{transform:none}
  .to-top{transform:none}
}