/* =====================================================================
   必博体育 · 高原竞技档案库  /assets/site.css  全站共享层
   0 变量 / 1 重置 / 2 中文排版 / 3 通用组件 / 4 头部 / 5 页脚 / 6 响应式
   ===================================================================== */

/* ---------- 0. 变量 ---------- */
:root{
  --ink-900:#0A1A2F;
  --ink-800:#12294A;
  --ink-700:#1E4A7A;
  --paper:#F5F0E6;
  --paper-2:#E6DCC8;
  --paper-card:#FFFCF4;
  --text:#171A1F;
  --muted:#55606E;
  --snow:#F2F6FB;
  --flag-blue:#2F6FB5;
  --flag-red:#C43A2E;
  --flag-green:#1E7A50;
  --flag-yellow:#E2A81E;
  --flag-white:#FFFFFF;
  --glass:rgba(18,41,74,.72);
  --glass-line:rgba(242,246,251,.16);
  --wrap:1320px;
  --measure:34em;
  --radius-sm:10px;
  --radius-md:14px;
  --radius-lg:20px;
  --radius-pill:999px;
  --shadow-float:0 22px 48px -28px rgba(10,26,47,.78);
  --font-body:"Noto Sans SC","思源黑体","PingFang SC","Microsoft YaHei",system-ui,-apple-system,sans-serif;
  --font-display:"Noto Sans SC","思源黑体","PingFang SC",system-ui,-apple-system,sans-serif;
  --font-editorial:"Noto Serif SC","思源宋体","Songti SC",Georgia,serif;
  --font-mono:"JetBrains Mono","IBM Plex Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
}

/* ---------- 1. 重置 ---------- */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{margin:0;font-family:var(--font-body);font-size:17px;font-weight:400;line-height:1.85;
  color:var(--text);background:var(--paper);
  -webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}
h1,h2,h3,h4,h5,h6,p,ul,ol,li,figure,blockquote,dl,dd{margin:0;padding:0}
ul,ol{list-style:none}
img,svg,video{display:block;max-width:100%;height:auto}
button,input,select,textarea{font:inherit;color:inherit;margin:0}
button{background:none;border:0;cursor:pointer}
a{color:inherit;text-decoration:none}
table{border-collapse:collapse;border-spacing:0;width:100%}
::selection{background:var(--flag-yellow);color:var(--ink-900)}
:focus-visible{outline:2px solid var(--flag-yellow);outline-offset:2px;border-radius:6px}
#main-content{scroll-margin-top:120px}

/* ---------- 2. 中文排版 ---------- */
.arc-display{font-family:var(--font-display);font-weight:900;letter-spacing:.08em;line-height:1.05;
  font-size:clamp(2.4rem,6vw,5.2rem);text-wrap:balance}
.arc-title{font-family:var(--font-editorial);font-weight:600;letter-spacing:.02em;line-height:1.35;
  font-size:clamp(1.5rem,3vw,2.6rem);text-wrap:balance}
.arc-lede{font-size:clamp(1rem,1.35vw,1.15rem);line-height:1.9;color:var(--muted);max-width:40em}
.arc-prose{max-width:var(--measure);font-size:17.5px;line-height:1.85;letter-spacing:.01em}
.arc-prose p+p{margin-top:1.15em}
.arc-prose h2{margin-top:1.8em;margin-bottom:.5em}
.arc-prose h3{margin-top:1.5em;margin-bottom:.4em;font-family:var(--font-editorial);font-size:1.3rem}
.arc-prose a{color:var(--flag-blue);border-bottom:1px solid rgba(47,111,181,.35)}
.arc-prose a:hover{border-bottom-color:var(--flag-blue)}
.arc-overline{display:inline-flex;align-items:center;gap:10px;font-size:12px;font-weight:600;
  letter-spacing:.24em;color:var(--flag-blue);text-transform:uppercase}
.arc-overline::before{content:"";width:26px;height:2px;background:currentColor}
.arc-label{font-size:12px;font-weight:500;letter-spacing:.14em;color:var(--muted);text-transform:uppercase}
.arc-num{font-family:var(--font-mono);font-variant-numeric:tabular-nums;letter-spacing:.02em}
.arc-quote{margin:0;padding-left:clamp(18px,3vw,32px);border-left:3px solid var(--flag-yellow);
  font-family:var(--font-editorial);font-size:clamp(1.1rem,1.8vw,1.4rem);line-height:1.75;color:var(--ink-800)}
.arc-visually-hidden{position:absolute!important;width:1px;height:1px;padding:0;margin:-1px;
  overflow:hidden;clip:rect(0 0 0 0);clip-path:inset(50%);white-space:nowrap;border:0}

/* ---------- 3. 通用组件 ---------- */
.arc-container{width:100%;max-width:var(--wrap);margin-inline:auto;padding-inline:clamp(16px,4vw,44px)}

.arc-section{padding-block:clamp(56px,9vw,120px)}
.arc-section--tight{padding-block:clamp(30px,5vw,64px)}
.arc-section--paper{background:var(--paper)}
.arc-section--band{background:var(--paper-2)}
.arc-section--ink{background:var(--ink-900);color:var(--snow)}
.arc-section--ink .arc-lede{color:rgba(242,246,251,.72)}
.arc-section--ink .arc-overline{color:var(--flag-yellow)}
.arc-section--ink .arc-label,
.arc-section--ink .arc-card__meta{color:rgba(242,246,251,.6)}
.arc-section--ink .arc-quote{color:var(--snow)}
.arc-section--ink .arc-prose a{color:var(--flag-yellow)}

.arc-grid{display:grid;gap:clamp(16px,2.4vw,28px)}
.arc-grid--2{grid-template-columns:repeat(2,minmax(0,1fr))}
.arc-grid--3{grid-template-columns:repeat(3,minmax(0,1fr))}
.arc-grid--split{grid-template-columns:minmax(0,7fr) minmax(0,5fr);align-items:start}

.arc-card{padding:clamp(18px,2.4vw,28px);border-radius:var(--radius-lg);border:1px solid transparent}
.arc-card--paper{background:var(--paper-card);border-color:var(--paper-2);
  box-shadow:0 18px 36px -30px rgba(10,26,47,.6)}
.arc-card--glass{background:var(--glass);border-color:var(--glass-line);color:var(--snow);
  -webkit-backdrop-filter:blur(14px);backdrop-filter:blur(14px);box-shadow:var(--shadow-float)}
.arc-card__title{font-family:var(--font-editorial);font-weight:600;font-size:1.15rem;letter-spacing:.02em;line-height:1.5}
.arc-card__meta{display:block;margin-top:8px;font-family:var(--font-mono);font-size:12px;letter-spacing:.1em;color:var(--muted)}

.arc-btn{display:inline-flex;align-items:center;gap:10px;padding:13px 26px;border-radius:var(--radius-pill);
  font-size:14px;font-weight:600;letter-spacing:.14em;border:1px solid transparent;
  transition:transform .22s ease,background .22s ease,color .22s ease,border-color .22s ease}
.arc-btn--primary{background:var(--flag-blue);color:var(--snow)}
.arc-btn--primary:hover{background:#3C82CC;transform:translateY(-2px)}
.arc-btn--accent{background:var(--flag-yellow);color:var(--ink-900)}
.arc-btn--accent:hover{background:#F0BC3C;transform:translateY(-2px)}
.arc-btn--ghost{border-color:currentColor;color:var(--ink-800)}
.arc-btn--ghost:hover{background:rgba(47,111,181,.12)}
.arc-section--ink .arc-btn--ghost{color:var(--snow)}
.arc-btn--quiet{padding:0;border:0;color:var(--flag-blue);text-decoration:underline;text-underline-offset:4px}

.arc-breadcrumb{display:flex;flex-wrap:wrap;align-items:center;gap:8px;font-size:12px;
  letter-spacing:.12em;color:var(--muted)}
.arc-breadcrumb__link{color:var(--flag-blue)}
.arc-breadcrumb__sep{opacity:.5}
.arc-section--ink .arc-breadcrumb{color:rgba(242,246,251,.6)}
.arc-section--ink .arc-breadcrumb__link{color:var(--flag-yellow)}

.arc-divider{height:1px;border:0;margin-block:clamp(28px,4vw,48px);
  background:linear-gradient(90deg,var(--ink-700),rgba(30,74,122,0))}
.arc-flagstrip{display:flex;width:88px;height:4px;border-radius:var(--radius-pill);overflow:hidden}
.arc-flagstrip .arc-band__seg{height:100%}

.arc-tag{display:inline-flex;align-items:center;gap:6px;padding:4px 12px;border-radius:var(--radius-pill);
  font-size:12px;letter-spacing:.1em;border:1px solid rgba(23,26,31,.16);color:var(--muted)}
.arc-tag--up{color:var(--flag-green);border-color:rgba(30,122,80,.42);background:rgba(30,122,80,.09)}
.arc-tag--down{color:var(--flag-red);border-color:rgba(196,58,46,.42);background:rgba(196,58,46,.09)}
.arc-tag--flat{color:var(--flag-blue);border-color:rgba(47,111,181,.42);background:rgba(47,111,181,.09)}

.arc-figure{display:grid;gap:10px;margin:0}
.arc-figure__img{position:relative;width:100%;aspect-ratio:16/10;border-radius:var(--radius-lg);
  overflow:hidden;background:linear-gradient(155deg,var(--ink-800),var(--ink-900) 58%,var(--ink-700));
  box-shadow:var(--shadow-float)}
.arc-figure__img img{width:100%;height:100%;object-fit:cover;filter:saturate(.72) contrast(1.06)}
.arc-figure__img::after{content:"";position:absolute;inset:0;pointer-events:none;
  background-image:linear-gradient(rgba(242,246,251,.09) 1px,transparent 1px),
                   linear-gradient(90deg,rgba(242,246,251,.09) 1px,transparent 1px);
  background-size:44px 44px}
.arc-figure__caption{font-size:12.5px;line-height:1.7;color:var(--muted)}
.arc-figure--plate .arc-figure__img{aspect-ratio:4/3;border-radius:4px;padding:10px;background:var(--paper-2);
  box-shadow:none}
.arc-figure--plate .arc-figure__img img{border-radius:2px;filter:saturate(.45) sepia(.22) contrast(1.05)}
.arc-figure--plate .arc-figure__img::after{display:none}
.arc-figure--wide{grid-column:1/-1}

.arc-table__wrap{overflow-x:auto;border:1px solid var(--paper-2);border-radius:var(--radius-md);
  background:var(--paper-card)}
.arc-table{width:100%;min-width:560px;font-size:14.5px}
.arc-table th,.arc-table td{padding:11px 16px;text-align:left;border-bottom:1px solid rgba(23,26,31,.1)}
.arc-table thead th{background:var(--paper-2);color:var(--ink-800);font-size:12px;font-weight:600;
  letter-spacing:.14em;white-space:nowrap}
.arc-table tbody tr:nth-child(even){background:rgba(230,220,200,.35)}
.arc-table td.arc-num{text-align:right}

.arc-spy{position:sticky;top:132px;display:block}
.arc-spy__list{display:grid;gap:6px;border-left:1px solid var(--paper-2);padding-left:14px}
.arc-spy__link{display:block;font-size:12.5px;letter-spacing:.08em;color:var(--muted);
  padding:3px 0;transition:color .2s ease,transform .2s ease}
.arc-spy__link[aria-current="true"]{color:var(--flag-blue);transform:translateX(3px);
  box-shadow:inset 2px 0 0 var(--flag-yellow)}

/* 进场显现 */
html.arc-js [data-reveal]{opacity:0;transform:translateY(12px);
  transition:opacity .6s ease,transform .6s ease}
html.arc-js [data-reveal].is-visible{opacity:1;transform:none}

/* ---------- 4. 头部 ---------- */
.arc-header{position:sticky;top:0;z-index:80;color:var(--snow);
  background:rgba(10,26,47,.93);
  -webkit-backdrop-filter:blur(16px) saturate(1.3);backdrop-filter:blur(16px) saturate(1.3);
  border-bottom:1px solid rgba(47,111,181,.42)}

.arc-skip{position:absolute;left:16px;top:-64px;z-index:200;padding:10px 18px;
  background:var(--flag-yellow);color:var(--ink-900);font-weight:700;font-size:13px;letter-spacing:.1em;
  border-radius:0 0 12px 12px;transition:top .2s ease}
.arc-skip:focus{top:0}

.arc-header__band{display:flex;width:100%;height:6px;overflow:hidden;
  animation:arc-band-sway 13s ease-in-out infinite alternate}
.arc-band__seg{display:block;height:100%}
.arc-band__seg--blue{background:var(--flag-blue);flex:32}
.arc-band__seg--white{background:var(--flag-white);flex:12}
.arc-band__seg--red{background:var(--flag-red);flex:22}
.arc-band__seg--green{background:var(--flag-green);flex:18}
.arc-band__seg--yellow{background:var(--flag-yellow);flex:16}
.arc-header[data-section="values"] .arc-band__seg--blue{flex:40}
.arc-header[data-section="values"] .arc-band__seg--yellow{flex:8}
.arc-header[data-section="projects"] .arc-band__seg--blue{flex:18}
.arc-header[data-section="projects"] .arc-band__seg--yellow{flex:30}
.arc-header[data-section="stories"] .arc-band__seg--red{flex:34}
.arc-header[data-section="stories"] .arc-band__seg--blue{flex:20}
.arc-header[data-section="knowledge"] .arc-band__seg--green{flex:32}
.arc-header[data-section="knowledge"] .arc-band__seg--red{flex:12}
.arc-header[data-section="inquiry"] .arc-band__seg--white{flex:26}
.arc-header[data-section="inquiry"] .arc-band__seg--blue{flex:24}
.arc-header[data-section="legal"] .arc-band__seg--white{flex:34}
.arc-header[data-section="legal"] .arc-band__seg--yellow{flex:6}
@keyframes arc-band-sway{
  from{transform:translate3d(0,0,0) rotate(-.12deg)}
  to{transform:translate3d(0,-1px,0) rotate(.12deg)}
}

.arc-progress{position:relative;height:2px;background:rgba(242,246,251,.1)}
.arc-progress__bar{display:block;width:0;height:100%;
  background:linear-gradient(90deg,var(--flag-blue),var(--flag-yellow) 45%,var(--flag-red) 72%,var(--flag-green));
  transition:width .12s linear}

.arc-header__inner{position:relative;display:grid;grid-template-columns:minmax(0,1fr) auto minmax(0,1fr);
  align-items:center;gap:clamp(12px,2vw,28px);
  width:100%;max-width:var(--wrap);margin-inline:auto;
  min-height:66px;padding:10px clamp(16px,4vw,44px);
  transition:min-height .28s ease,padding .28s ease}

.arc-brand{display:inline-flex;align-items:center;gap:10px;color:var(--snow);grid-column:1;justify-self:start}
.arc-brand__mark{flex:none;width:30px;height:30px;border-radius:9px;
  background:repeating-linear-gradient(135deg,
    var(--flag-blue) 0 6px,var(--flag-white) 6px 10px,var(--flag-red) 10px 16px,
    var(--flag-green) 16px 20px,var(--flag-yellow) 20px 26px);
  box-shadow:inset 0 0 0 1px rgba(242,246,251,.3),0 8px 16px -10px rgba(0,0,0,.9)}
.arc-brand__text{display:flex;flex-direction:column;line-height:1.2}
.arc-brand__name{font-family:var(--font-display);font-weight:900;font-size:1.06rem;letter-spacing:.2em}
.arc-brand__sub{display:block;overflow:hidden;max-height:24px;font-family:var(--font-mono);
  font-size:11px;letter-spacing:.12em;color:rgba(242,246,251,.62);
  transition:max-height .26s ease,opacity .24s ease}

.arc-nav{grid-column:2;justify-self:center}
.arc-nav__list{display:flex;align-items:center;gap:2px;padding:5px;
  border-radius:var(--radius-pill);background:rgba(18,41,74,.68);border:1px solid var(--glass-line);
  -webkit-backdrop-filter:blur(8px);backdrop-filter:blur(8px)}
.arc-nav__item{display:block}
.arc-nav__link{display:inline-flex;align-items:center;gap:7px;padding:8px 15px;white-space:nowrap;
  border-radius:var(--radius-pill);font-size:13.5px;font-weight:500;letter-spacing:.08em;
  color:rgba(242,246,251,.76);transition:background .22s ease,color .22s ease,box-shadow .22s ease}
.arc-nav__link:hover{background:rgba(47,111,181,.34);color:var(--snow)}
.arc-nav__link[aria-current="page"]{color:var(--snow);background:rgba(226,168,30,.16);
  box-shadow:inset 0 0 0 1px rgba(226,168,30,.55)}
.arc-nav__dot{flex:none;width:6px;height:6px;border-radius:50%;background:var(--flag-yellow);
  opacity:0;transform:scale(.4);transition:opacity .2s ease,transform .2s ease}
.arc-nav__link[aria-current="page"] .arc-nav__dot{opacity:1;transform:scale(1)}

.arc-header__tools{display:flex;align-items:center;gap:8px;grid-column:3;justify-self:end}
.arc-search{position:relative;display:flex;align-items:center;width:172px;
  transition:width .3s ease,opacity .26s ease}
.arc-search::before{content:"";position:absolute;left:12px;top:50%;width:8px;height:8px;margin-top:-6px;
  border:1.5px solid rgba(242,246,251,.55);border-radius:50%;pointer-events:none;
  transition:opacity .2s ease}
.arc-search::after{content:"";position:absolute;left:19px;top:50%;width:6px;height:1.5px;margin-top:2px;
  background:rgba(242,246,251,.55);transform:rotate(45deg);pointer-events:none;
  transition:opacity .2s ease}
.arc-search__input{width:100%;padding:8px 12px 8px 27px;border-radius:var(--radius-pill);
  background:rgba(242,246,251,.08);border:1px solid rgba(242,246,251,.2);color:var(--snow);
  font-size:13px;letter-spacing:.03em;-webkit-appearance:none;appearance:none;
  transition:background .2s ease,border-color .2s ease,padding .3s ease}
.arc-search__input::placeholder{color:rgba(242,246,251,.48)}
.arc-search__input:focus{background:rgba(242,246,251,.14);border-color:rgba(226,168,30,.7)}
.arc-search__status{position:absolute;top:calc(100% + 8px);right:0;z-index:5;pointer-events:none;
  padding:3px 10px;border-radius:var(--radius-pill);white-space:nowrap;
  font-size:11px;letter-spacing:.12em;color:var(--flag-yellow);
  background:rgba(10,26,47,.96);border:1px solid rgba(226,168,30,.4);
  opacity:0;transform:translateY(-4px);transition:opacity .2s ease,transform .2s ease}
.arc-search__status[data-active="true"]{opacity:1;transform:none}

.arc-index-btn{padding:8px 14px;border-radius:var(--radius-pill);border:1px solid var(--glass-line);
  background:rgba(18,41,74,.7);color:rgba(242,246,251,.85);
  font-size:12px;font-weight:500;letter-spacing:.18em;transition:background .22s ease,color .22s ease,border-color .22s ease}
.arc-index-btn:hover{background:rgba(47,111,181,.4);color:#fff}
.arc-index-btn[aria-expanded="true"]{background:var(--flag-yellow);border-color:var(--flag-yellow);color:var(--ink-900)}

.arc-nav-toggle{display:none;flex-direction:column;align-items:center;justify-content:center;gap:4px;
  width:40px;height:40px;border-radius:12px;border:1px solid var(--glass-line);background:rgba(18,41,74,.7)}
.arc-nav-toggle__bar{display:block;width:16px;height:2px;border-radius:2px;background:var(--snow);
  transition:transform .26s ease,opacity .2s ease}
.arc-nav-toggle[aria-expanded="true"] .arc-nav-toggle__bar:nth-child(1){transform:translateY(6px) rotate(45deg)}
.arc-nav-toggle[aria-expanded="true"] .arc-nav-toggle__bar:nth-child(2){opacity:0}
.arc-nav-toggle[aria-expanded="true"] .arc-nav-toggle__bar:nth-child(3){transform:translateY(-6px) rotate(-45deg)}

.arc-index-panel{position:absolute;top:calc(100% - 4px);right:clamp(16px,4vw,44px);z-index:90;
  width:min(380px,calc(100vw - 32px));padding:18px;border-radius:var(--radius-lg);
  background:rgba(10,26,47,.96);border:1px solid var(--glass-line);box-shadow:var(--shadow-float);
  -webkit-backdrop-filter:blur(18px);backdrop-filter:blur(18px);
  transition:opacity .24s ease,transform .24s ease,visibility .24s}
.arc-index-panel[data-open="false"]{opacity:0;visibility:hidden;transform:translateY(-10px);pointer-events:none}
.arc-index__head{margin-bottom:12px;font-size:11px;font-weight:600;letter-spacing:.24em;
  color:var(--flag-yellow);text-transform:uppercase}
.arc-index__list{display:grid;gap:2px}
.arc-index__item{display:block}
.arc-index__link{display:grid;grid-template-columns:auto minmax(0,1fr);gap:2px 12px;
  padding:9px 10px;border-radius:12px;transition:background .18s ease}
.arc-index__link:hover{background:rgba(47,111,181,.28)}
.arc-index__num{grid-row:1/3;font-family:var(--font-mono);font-size:12px;color:var(--flag-yellow);padding-top:3px}
.arc-index__label{font-size:14px;font-weight:500;letter-spacing:.06em;color:var(--snow)}
.arc-index__desc{font-size:11.5px;letter-spacing:.04em;color:rgba(242,246,251,.55)}
.arc-index__link[aria-current="page"] .arc-index__label{color:var(--flag-yellow)}

.arc-header--compact .arc-header__inner{min-height:52px;padding-block:6px}
.arc-header--compact .arc-brand__sub{max-height:0;opacity:0}
.arc-header--compact .arc-search{width:0;opacity:0;pointer-events:none}
.arc-header--compact .arc-search::before,
.arc-header--compact .arc-search::after{opacity:0}
.arc-header--compact .arc-search__input{padding-inline:0;border-width:0}

/* ---------- 5. 页脚 ---------- */
.arc-footer{position:relative;background:var(--ink-900);color:var(--snow)}
.arc-footer__band{display:flex;width:100%;height:6px}
.arc-footer__band .arc-band__seg{height:100%}
.arc-footer__inner{display:grid;grid-template-columns:minmax(0,1.4fr) minmax(0,1fr) minmax(0,1.25fr);
  gap:clamp(24px,4vw,60px);padding-block:clamp(40px,6vw,76px)}
.arc-footer__col{min-width:0}
.arc-footer__col--brand .arc-brand{margin-bottom:16px}
.arc-brand--footer .arc-brand__mark{width:34px;height:34px}
.arc-footer__title{margin-bottom:16px;font-family:var(--font-display);font-size:12px;font-weight:700;
  letter-spacing:.22em;color:var(--flag-yellow)}
.arc-footer__lede{max-width:34em;margin-top:10px;font-size:14px;line-height:1.9;color:rgba(242,246,251,.7)}
.arc-footer__icp{margin-top:16px;font-family:var(--font-mono);font-size:12px;letter-spacing:.08em;
  color:rgba(242,246,251,.55)}
.arc-footer__list{display:grid;gap:9px}
.arc-footer__link{display:inline-block;font-size:14px;color:rgba(242,246,251,.72);
  transition:color .2s ease,transform .2s ease}
.arc-footer__link:hover{color:var(--snow);transform:translateX(3px)}
.arc-footer__contact{display:flex;flex-wrap:wrap;align-items:center;gap:8px;font-size:14px;
  color:rgba(242,246,251,.75);line-height:1.7}
.arc-footer__key{flex:none;min-width:3.6em;font-size:11px;letter-spacing:.18em;color:rgba(242,246,251,.45)}
.arc-footer__value{min-width:0;font-family:var(--font-mono);font-size:13px;color:var(--snow);
  word-break:break-word}
.arc-footer__note{margin-top:14px;font-size:12.5px;line-height:1.75;color:rgba(242,246,251,.5)}
.arc-copy{display:inline-flex;align-items:center;padding:5px 12px;border-radius:var(--radius-pill);
  border:1px solid var(--glass-line);background:rgba(47,111,181,.22);color:var(--snow);
  font-size:11px;letter-spacing:.16em;transition:background .2s ease,border-color .2s ease}
.arc-copy:hover{background:rgba(47,111,181,.48);border-color:rgba(226,168,30,.6)}
.arc-copy__status{font-size:11px;letter-spacing:.1em;color:var(--flag-yellow)}
.arc-footer__legal{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;
  gap:12px 24px;padding-block:20px;border-top:1px solid rgba(242,246,251,.12)}
.arc-footer__legal-list{display:flex;flex-wrap:wrap;gap:8px 20px}
.arc-footer__legal-link{font-size:12.5px;letter-spacing:.08em;color:rgba(242,246,251,.6);
  border-bottom:1px solid transparent;transition:color .2s ease,border-color .2s ease}
.arc-footer__legal-link:hover{color:var(--flag-yellow);border-bottom-color:var(--flag-yellow)}
.arc-footer__meta{font-family:var(--font-mono);font-size:11.5px;letter-spacing:.06em;
  color:rgba(242,246,251,.42)}

.arc-top{position:fixed;right:clamp(14px,3vw,28px);bottom:clamp(14px,3vw,28px);z-index:70;
  display:inline-flex;align-items:center;gap:8px;padding:10px 16px;border-radius:var(--radius-pill);
  background:rgba(10,26,47,.92);border:1px solid var(--glass-line);color:var(--snow);
  font-size:12px;letter-spacing:.14em;-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);
  opacity:0;visibility:hidden;transform:translateY(10px);
  transition:opacity .25s ease,transform .25s ease,visibility .25s}
.arc-top[data-visible="true"]{opacity:1;visibility:visible;transform:none}
.arc-top__glyph{width:0;height:0;border-left:5px solid transparent;border-right:5px solid transparent;
  border-bottom:6px solid var(--flag-yellow)}

/* ---------- 6. 响应式 ---------- */
@media (max-width:1220px){
  .arc-header__inner{grid-template-columns:minmax(0,1fr) auto}
  .arc-nav{position:absolute;top:calc(100% + 8px);left:clamp(16px,4vw,44px);right:clamp(16px,4vw,44px);
    z-index:95;opacity:0;visibility:hidden;transform:translateY(-10px);
    transition:opacity .24s ease,transform .24s ease,visibility .24s}
  .arc-nav[data-open="true"]{opacity:1;visibility:visible;transform:none}
  .arc-nav__list{flex-direction:column;align-items:stretch;gap:2px;padding:10px;border-radius:22px;
    background:rgba(10,26,47,.97);box-shadow:var(--shadow-float)}
  .arc-nav__link{justify-content:flex-start;padding:12px 16px;border-radius:14px;
    font-size:15px;letter-spacing:.1em}
  .arc-nav-toggle{display:flex}
}
@media (max-width:960px){
  .arc-grid--2,.arc-grid--3,.arc-grid--split{grid-template-columns:minmax(0,1fr)}
  .arc-spy{position:static}
  .arc-footer__inner{grid-template-columns:minmax(0,1fr) minmax(0,1fr)}
  .arc-footer__col--brand{grid-column:1/-1}
}
@media (max-width:760px){
  body{font-size:16.5px}
  .arc-brand__sub{max-height:0;opacity:0}
  .arc-search{width:128px}
  .arc-header__inner{min-height:58px}
  .arc-footer__legal{flex-direction:column;align-items:flex-start}
}
@media (max-width:520px){
  .arc-brand__name{font-size:.96rem;letter-spacing:.14em}
  .arc-search{width:100px}
  .arc-index-btn{padding:8px 10px;font-size:11px;letter-spacing:.1em}
  .arc-footer__inner{grid-template-columns:minmax(0,1fr)}
  .arc-index-panel{right:12px;left:12px;width:auto}
  .arc-top{padding:9px 13px;font-size:11px}
}

@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.arc-js [data-reveal]{opacity:1;transform:none}
  .arc-header__band{animation:none}
}