:root{
  --ink:#0F1B2D;
  --ink-2:#1B2A44;
  --ink-3:#16243A;
  --orange:#FF6B1A;
  --orange-soft:#FFB27A;
  --orange-text:#B33F00;
  --orange-veil:#FFD6C2;
  --cyan:#3DE0FF;
  --cyan-soft:#8AF2FF;
  --mist:#F5F7FA;
  --line:#C7D3E3;
  --rail-w:clamp(248px,19vw,296px);
  --gutter:clamp(16px,3.2vw,56px);
  --baseline:8px;
  --hair:rgba(199,211,227,.18);
  --hair-strong:rgba(199,211,227,.32);
  --font-serif:"Source Han Serif SC","Noto Serif SC","Songti SC","SimSun",serif;
  --font-sans:"Source Han Sans SC","Noto Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  --font-mono:"IBM Plex Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
}

*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;text-size-adjust:100%}
body,h1,h2,h3,h4,h5,p,figure,blockquote,dl,dd{margin:0}
ul,ol{margin:0;padding:0;list-style:none}
img,svg{display:block;max-width:100%}
button{font:inherit;color:inherit;background:none;border:0;cursor:pointer}
a{color:inherit}
hr{border:0;margin:0}

body{
  background:var(--ink);
  color:var(--mist);
  font-family:var(--font-sans);
  font-size:16px;
  line-height:1.7;
  font-weight:400;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}
#main-content{display:block;scroll-margin-top:16px}

:where(a,button,summary,[tabindex]):focus-visible{
  outline:2px solid var(--cyan);
  outline-offset:3px;
}

h1,h2,h3,h4{font-family:var(--font-serif);font-weight:700;line-height:1.18;letter-spacing:-.005em}
h1{font-size:clamp(2.1rem,1.4rem + 2.8vw,4.2rem)}
h2{font-size:clamp(1.6rem,1.2rem + 1.6vw,2.5rem)}
h3{font-size:clamp(1.15rem,1rem + .6vw,1.5rem)}

.display{font-family:var(--font-serif);font-weight:700;line-height:1.06;letter-spacing:-.015em;font-size:clamp(2.3rem,1.5rem + 3.2vw,4.4rem)}
.eyebrow{
  display:inline-block;
  font-family:var(--font-sans);
  font-size:11px;
  font-weight:700;
  letter-spacing:.24em;
  text-transform:uppercase;
  color:var(--cyan);
}
.lede{font-size:clamp(1rem,.95rem + .35vw,1.15rem);line-height:1.75;color:rgba(245,247,250,.82);max-width:56ch}
.mono{font-family:var(--font-mono);font-variant-numeric:tabular-nums;letter-spacing:.04em}
.num{font-family:var(--font-mono);font-variant-numeric:tabular-nums;letter-spacing:.08em;color:var(--cyan)}
.rule{height:1px;background:var(--hair)}

.container{width:min(1180px,calc(100% - 2 * var(--gutter)));margin-inline:auto}
.section{padding-block:clamp(44px,7vw,104px)}
.grid{display:grid;gap:clamp(16px,2.4vw,32px)}
.grid--2{grid-template-columns:repeat(auto-fit,minmax(268px,1fr))}
.grid--3{grid-template-columns:repeat(auto-fit,minmax(232px,1fr))}

.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:10px;
  padding:13px 22px;border:1px solid var(--orange);
  background:var(--orange);color:#0F1B2D;
  font-family:var(--font-sans);font-weight:700;font-size:14px;letter-spacing:.06em;
  text-decoration:none;line-height:1.2;
  transition:background .18s ease,color .18s ease,border-color .18s ease;
}
.btn:hover{background:var(--orange-soft);border-color:var(--orange-soft);color:#0F1B2D}
.btn--ghost{background:transparent;color:var(--mist);border-color:var(--hair-strong)}
.btn--ghost:hover{background:transparent;color:var(--cyan);border-color:var(--cyan)}
.btn--sm{padding:9px 16px;font-size:13px}

.card{
  position:relative;
  background:var(--ink-2);
  border:1px solid var(--hair);
  padding:clamp(18px,2.2vw,28px);
  transition:border-color .18s ease,background .18s ease;
}
.card::before{
  content:"";position:absolute;top:0;left:0;width:0;height:2px;
  background:linear-gradient(90deg,var(--orange),var(--cyan));
  transition:width .22s ease;
}
.card:hover,.card:focus-within{border-color:rgba(255,107,26,.55)}
.card:hover::before,.card:focus-within::before{width:100%}
.card__head{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-bottom:14px}
.card__title{font-family:var(--font-serif);font-size:clamp(1.05rem,.98rem + .45vw,1.35rem);line-height:1.32;color:var(--mist)}
.card__body{font-size:15px;line-height:1.72;color:rgba(245,247,250,.72)}

.tag{
  display:inline-flex;align-items:center;gap:6px;
  padding:3px 10px;
  border:1px solid rgba(255,107,26,.5);
  color:var(--orange-soft);
  font-size:11.5px;letter-spacing:.1em;line-height:1.6;
}

.table-wrap{
  overflow:auto;
  max-height:540px;
  border:1px solid var(--hair);
  background:rgba(27,42,68,.55);
  -webkit-overflow-scrolling:touch;
}
.data-table{width:100%;border-collapse:collapse;font-size:14.5px}
.data-table th,.data-table td{padding:11px 14px;text-align:left;border-bottom:1px solid rgba(199,211,227,.12);white-space:nowrap}
.data-table thead th{
  position:sticky;top:0;z-index:2;
  background:var(--ink-2);color:var(--cyan);
  font-family:var(--font-mono);font-size:11px;letter-spacing:.14em;text-transform:uppercase;
}
.data-table td.is-num{text-align:right;font-family:var(--font-mono);font-variant-numeric:tabular-nums}
.data-table tbody tr:hover{background:rgba(138,242,255,.10)}

.faq{border-top:1px solid var(--hair)}
.faq__item{border-bottom:1px solid var(--hair)}
.faq__q{
  display:flex;align-items:center;justify-content:space-between;gap:16px;
  padding:16px 0;list-style:none;cursor:pointer;
  font-weight:700;font-size:clamp(.98rem,.94rem + .2vw,1.08rem);color:var(--mist);
}
.faq__q::-webkit-details-marker{display:none}
.faq__q::after{content:"+";flex:none;font-family:var(--font-mono);color:var(--orange);font-size:18px;line-height:1}
.faq__item[open] .faq__q::after{content:"–";color:var(--cyan)}
.faq__a{padding:0 0 18px;max-width:64ch;color:rgba(245,247,250,.78);font-size:15.5px}

.crumbs{font-size:13px;color:var(--line)}
.crumbs ol{display:flex;flex-wrap:wrap;align-items:center;gap:8px}
.crumbs li{display:inline-flex;align-items:center;gap:8px}
.crumbs li + li::before{content:"／";color:rgba(199,211,227,.45)}
.crumbs a{color:var(--line);text-decoration:none;border-bottom:1px solid transparent;transition:color .18s ease,border-color .18s ease}
.crumbs a:hover{color:var(--orange-soft);border-bottom-color:var(--cyan)}

.prose{max-width:68ch;font-size:17px;line-height:1.85;color:rgba(245,247,250,.86)}
.prose > * + *{margin-top:1.1em}
.prose h2,.prose h3{color:var(--mist);margin-top:1.8em}
.prose a{color:var(--cyan);text-decoration:underline;text-underline-offset:3px}

.frame{
  position:relative;overflow:hidden;
  background:linear-gradient(145deg,var(--ink-3),var(--ink) 70%);
  border:1px solid var(--hair);
}
.frame::after{
  content:"";position:absolute;inset:0;pointer-events:none;opacity:.65;
  background:
    repeating-linear-gradient(90deg,transparent 0 63px,rgba(199,211,227,.10) 63px 64px),
    repeating-linear-gradient(0deg,transparent 0 63px,rgba(199,211,227,.10) 63px 64px);
}
.frame img{width:100%;height:100%;object-fit:cover}
.frame--wide{aspect-ratio:16/9}
.frame--tall{aspect-ratio:3/4}
.frame--square{aspect-ratio:1/1}

/* ---------- header ---------- */
.site-header{position:relative;z-index:60}

.skip-link{
  position:fixed;top:10px;left:10px;z-index:400;
  padding:10px 18px;
  background:var(--cyan);color:var(--ink);
  font-weight:700;font-size:14px;text-decoration:none;
  transform:translateY(-220%);
  transition:transform .18s ease;
}
.skip-link:focus{transform:translateY(0)}

.mobile-bar{
  position:sticky;top:0;z-index:70;
  display:flex;align-items:center;gap:10px;
  padding:12px var(--gutter);
  background:var(--ink);
  border-bottom:1px solid var(--hair);
}
.mobile-bar__brand{
  display:inline-flex;align-items:center;gap:9px;
  font-family:var(--font-sans);font-weight:800;font-size:16px;letter-spacing:.03em;
  color:var(--mist);text-decoration:none;
}
.mobile-bar__brand::before{
  content:"";width:9px;height:19px;background:var(--orange);transform:skewX(-14deg);flex:none;
}
.mobile-bar__meta{
  margin-left:auto;
  font-family:var(--font-mono);font-size:10.5px;letter-spacing:.2em;
  color:var(--cyan);text-transform:uppercase;
}

.nav-toggle{
  display:inline-flex;align-items:center;gap:9px;
  padding:9px 13px;
  border:1px solid var(--hair-strong);
  color:var(--mist);
  transition:border-color .18s ease,color .18s ease;
}
.nav-toggle:hover{border-color:var(--orange);color:var(--orange-soft)}
.nav-toggle__bars{position:relative;width:18px;height:12px;flex:none}
.nav-toggle__bars::before,.nav-toggle__bars::after{
  content:"";position:absolute;left:0;width:100%;height:1.5px;background:currentColor;
  transition:transform .2s ease,opacity .2s ease;
}
.nav-toggle__bars::before{top:2px}
.nav-toggle__bars::after{bottom:2px}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::before{transform:translateY(3.5px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::after{transform:translateY(-3.5px) rotate(-45deg)}
.nav-toggle__label{font-size:13px;letter-spacing:.1em;font-weight:700}

.rail{
  position:fixed;top:0;left:0;bottom:0;z-index:90;
  width:min(88vw,344px);
  display:flex;flex-direction:column;
  padding:22px 18px 20px;
  background:var(--ink);
  border-right:1px solid var(--hair-strong);
  overflow-y:auto;overscroll-behavior:contain;
  transform:translateX(-104%);
  transition:transform .28s cubic-bezier(.4,0,.2,1);
  box-shadow:24px 0 60px rgba(4,9,18,.55);
}
.rail[data-open="true"]{transform:none}

.rail__head{
  display:flex;align-items:flex-start;justify-content:space-between;gap:12px;
  padding-bottom:18px;border-bottom:1px solid var(--hair);
}
.rail__mark{display:grid;gap:8px;text-decoration:none;color:var(--mist)}
.rail__badge{display:block;width:38px;height:6px;background:var(--orange);transform:skewX(-22deg)}
.rail__wordmark{font-family:var(--font-sans);font-weight:800;font-size:20px;line-height:1.2;letter-spacing:.02em}
.rail__wordmark em{font-style:normal;color:var(--orange)}
.rail__tagline{font-family:var(--font-mono);font-size:9.5px;letter-spacing:.24em;color:var(--cyan)}
.rail__close{
  flex:none;display:inline-flex;align-items:center;justify-content:center;
  width:36px;height:36px;line-height:1;font-size:18px;
  border:1px solid var(--hair-strong);color:var(--mist);
  transition:border-color .18s ease,color .18s ease;
}
.rail__close:hover{border-color:var(--orange);color:var(--orange)}

.rail__nav{margin-top:16px}
.rail__list{display:flex;flex-direction:column;gap:2px}
.rail__link{
  position:relative;
  display:grid;grid-template-columns:34px 1fr;align-items:center;gap:6px;
  padding:14px 12px 14px 14px;
  border-left:2px solid transparent;
  color:var(--line);text-decoration:none;
  transition:color .18s ease,border-color .18s ease,background .18s ease;
}
.rail__link::before{
  content:"";position:absolute;top:0;bottom:0;left:0;width:0;
  background:linear-gradient(90deg,rgba(255,107,26,.30),rgba(255,107,26,0));
  transition:width .22s ease;pointer-events:none;
}
.rail__link:hover,.rail__link:focus-visible{color:var(--mist)}
.rail__link:hover::before,.rail__link:focus-visible::before{width:100%}
.rail__link:hover .rail__num,.rail__link:focus-visible .rail__num{color:var(--orange)}
.rail__num{
  font-family:var(--font-mono);font-size:11px;letter-spacing:.12em;
  color:rgba(199,211,227,.5);
  transition:color .18s ease;
}
.rail__label{font-size:15px;letter-spacing:.02em}
.rail__link[aria-current="page"]{
  color:var(--mist);
  border-left-color:var(--cyan);
  background:rgba(61,224,255,.08);
}
.rail__link[aria-current="page"] .rail__num{color:var(--orange)}
.rail__link[aria-current="page"] .rail__label{font-weight:700}

.rail__progress{margin-top:16px;height:2px;background:rgba(199,211,227,.18);position:relative;overflow:hidden}
.rail__progress-bar{
  position:absolute;inset:0;display:block;
  background:linear-gradient(90deg,var(--orange),var(--cyan));
  transform:scaleX(0);transform-origin:0 50%;
}

.rail__foot{margin-top:auto;padding-top:20px;border-top:1px solid var(--hair);display:grid;gap:12px}
.rail__foot-line{font-size:12.5px;line-height:1.65;color:rgba(199,211,227,.72)}
.rail__cta{
  display:inline-flex;align-items:center;justify-content:space-between;gap:10px;
  padding:11px 14px;border:1px solid var(--orange);
  color:var(--orange);text-decoration:none;
  font-size:13px;font-weight:700;letter-spacing:.08em;
  transition:background .18s ease,color .18s ease;
}
.rail__cta::after{content:"→";font-family:var(--font-mono)}
.rail__cta:hover{background:var(--orange);color:var(--ink)}

.rail-scrim{
  position:fixed;inset:0;z-index:85;
  background:rgba(6,12,22,.62);
  opacity:0;pointer-events:none;
  transition:opacity .24s ease;
}
.rail-scrim[data-visible="true"]{opacity:1;pointer-events:auto}

body[data-nav-open="true"]{overflow:hidden}

/* ---------- footer ---------- */
.site-footer{
  position:relative;
  margin-top:clamp(40px,7vw,96px);
  border-top:1px solid var(--hair);
  background:
    radial-gradient(72% 120% at 10% 100%,rgba(255,107,26,.16),transparent 62%),
    radial-gradient(56% 110% at 88% 100%,rgba(61,224,255,.11),transparent 64%),
    linear-gradient(180deg,#0C1727,#08111D);
}
.skyline{
  position:relative;height:78px;overflow:hidden;
  border-bottom:1px solid rgba(61,224,255,.16);
  background:
    repeating-linear-gradient(90deg,rgba(199,211,227,.22) 0 2px,transparent 2px 26px) bottom/100% 46px no-repeat,
    repeating-linear-gradient(90deg,transparent 0 12px,rgba(199,211,227,.14) 12px 14px,transparent 14px 34px) bottom/100% 68px no-repeat,
    linear-gradient(180deg,transparent,rgba(15,27,45,.9));
}
.footer__inner{
  width:min(1180px,calc(100% - 2 * var(--gutter)));
  margin-inline:auto;
  padding-block:clamp(30px,4.6vw,56px);
  display:grid;gap:clamp(26px,4vw,48px);
  grid-template-columns:1fr;
}
.footer__brand{display:grid;gap:14px;justify-items:start}
.footer__logo{
  display:inline-flex;align-items:center;gap:10px;
  font-family:var(--font-sans);font-weight:800;font-size:21px;letter-spacing:.02em;
  color:var(--mist);text-decoration:none;
}
.footer__logo::before{content:"";width:9px;height:20px;background:var(--orange);transform:skewX(-14deg);flex:none}
.footer__note{font-size:14.5px;line-height:1.7;color:rgba(199,211,227,.8);max-width:34ch}
.footer__col{display:grid;gap:14px;align-content:start;justify-items:start}
.footer__h{
  font-family:var(--font-mono);font-size:10.5px;font-weight:500;
  letter-spacing:.24em;text-transform:uppercase;color:var(--cyan);
}
.footer__list{display:grid;gap:9px}
.footer__link{
  display:inline-block;
  font-size:14px;color:var(--line);text-decoration:none;
  border-bottom:1px solid transparent;
  transition:color .18s ease,border-color .18s ease;
}
.footer__link:hover{color:var(--orange-soft);border-bottom-color:var(--cyan)}
.footer__meta{font-size:13.5px;color:rgba(199,211,227,.78);overflow-wrap:anywhere}
.footer__meta .mono{color:var(--mist);font-size:13px}

.footer__bar{border-top:1px solid var(--hair)}
.footer__bar-inner{
  width:min(1180px,calc(100% - 2 * var(--gutter)));
  margin-inline:auto;
  padding:16px 0 24px;
  display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;
  gap:12px 24px;
  font-size:12.5px;color:rgba(199,211,227,.62);
}
.footer__legal{display:flex;flex-wrap:wrap;gap:16px}
.footer__legal .footer__link{font-size:12.5px;color:rgba(199,211,227,.7)}
.footer__legal .footer__link:hover{color:var(--orange-soft)}
.footer__icp{font-family:var(--font-mono);font-size:12px;letter-spacing:.04em;color:rgba(199,211,227,.55)}

/* ---------- responsive ---------- */
@media (min-width:720px){
  .footer__inner{grid-template-columns:1.5fr 1fr 1.3fr}
}
@media (max-width:400px){
  .mobile-bar__meta{display:none}
}
@media (min-width:980px){
  body{padding-left:var(--rail-w)}
  .mobile-bar{display:none}
  .rail-scrim{display:none}
  .rail{
    position:fixed;
    width:var(--rail-w);
    transform:none;
    padding:30px 22px 24px;
    box-shadow:none;
    background:linear-gradient(180deg,#0F1B2D 0%,#0F1B2D 58%,#122036 100%);
  }
  .rail__close{display:none}
  .rail__nav{margin-top:22px}
  .rail__link{padding-block:13px}
  body[data-nav-open="true"]{overflow:auto}
}
@media (prefers-reduced-motion:no-preference){
  html{scroll-behavior:smooth}
}
@media (prefers-reduced-motion:reduce){
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
    scroll-behavior:auto !important;
  }
}