:root{
  --ink:#0B1B2B;
  --ink-2:#132A3D;
  --deep:#06131E;
  --slate:#5E7183;
  --mist:#AEBBC7;
  --cyan:#23D3C7;
  --orange:#FF8A3D;
  --violet:#7A6CFF;
  --paper:#F3F7FA;
  --pale:#DCE9EE;
  --text:#C6D2DB;

  --font-display:"PingFang SC","Hiragino Sans GB","Source Han Sans SC","Noto Sans SC","Microsoft YaHei",system-ui,-apple-system,"Segoe UI",sans-serif;
  --font-body:var(--font-display);
  --font-mono:ui-monospace,SFMono-Regular,"SF Mono",Menlo,Consolas,"Liberation Mono","PingFang SC",monospace;

  --shell:1240px;
  --gutter:clamp(18px,4vw,56px);
  --header-h:clamp(64px,9vw,76px);
  --ease:cubic-bezier(.4,.1,.2,1);
  --t:200ms;
  --r-sm:4px;
  --r-md:14px;
  --r-lg:26px;
}

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

html{
  -webkit-text-size-adjust:100%;
  scroll-behavior:smooth;
  scroll-padding-top:calc(var(--header-h) + 16px);
}

body{
  margin:0;
  background:var(--ink);
  color:var(--text);
  font-family:var(--font-body);
  font-size:1rem;
  line-height:1.75;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}

img,svg,video{display:block;max-width:100%;height:auto;}
ul,ol{margin:0;padding:0;list-style:none;}

h1,h2,h3,h4{
  margin:0 0 14px;
  font-family:var(--font-display);
  font-weight:800;
  letter-spacing:-.02em;
  line-height:1.18;
  color:var(--paper);
}
h1{font-size:clamp(2rem,4.4vw,3.1rem);}
h2{font-size:clamp(1.5rem,2.8vw,2.1rem);}
h3{font-size:clamp(1.14rem,1.8vw,1.4rem);letter-spacing:-.01em;}
h4{font-size:1rem;letter-spacing:0;}
p{margin:0 0 18px;}
p:last-child{margin-bottom:0;}

a{color:var(--cyan);text-decoration:underline;text-decoration-color:rgba(35,211,199,.4);text-underline-offset:3px;transition:color var(--t) var(--ease),text-decoration-color var(--t) var(--ease);}
a:hover{color:var(--violet);text-decoration-color:rgba(122,108,255,.6);}

:focus-visible{outline:2px solid var(--orange);outline-offset:3px;border-radius:3px;}

/* ---------- layout ---------- */
.shell{
  width:100%;
  max-width:var(--shell);
  margin-inline:auto;
  padding-inline:var(--gutter);
}

.grid-12{
  display:grid;
  grid-template-columns:repeat(12,minmax(0,1fr));
  gap:clamp(16px,2.4vw,32px);
}
.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;}

.divider{
  height:1px;
  border:0;
  margin:clamp(28px,4vw,48px) 0;
  background:linear-gradient(90deg,transparent,rgba(174,187,199,.34),transparent);
}

/* ---------- typography helpers ---------- */
.mono{font-family:var(--font-mono);font-variant-numeric:tabular-nums;}

.eyebrow{
  display:inline-flex;
  align-items:center;
  gap:10px;
  margin:0 0 14px;
  font-family:var(--font-mono);
  font-size:.74rem;
  letter-spacing:.18em;
  color:var(--cyan);
}
.eyebrow::before{
  content:"";
  width:22px;
  height:1px;
  background:var(--cyan);
}

.prose{max-width:68ch;font-size:1.02rem;line-height:1.78;color:var(--text);}
.prose h2,.prose h3{color:var(--paper);margin-top:clamp(26px,3.4vw,40px);}
.prose ul{list-style:disc;padding-left:1.25em;margin:0 0 18px;}
.prose ol{list-style:decimal;padding-left:1.35em;margin:0 0 18px;}
.prose li{margin-bottom:8px;}

/* ---------- buttons ---------- */
.btn{
  display:inline-flex;
  align-items:center;
  gap:10px;
  padding:13px 22px;
  border:1px solid transparent;
  border-radius:var(--r-sm) var(--r-md) var(--r-sm) var(--r-md);
  font-family:var(--font-display);
  font-weight:700;
  font-size:.94rem;
  letter-spacing:.01em;
  text-decoration:none;
  cursor:pointer;
  transition:transform var(--t) var(--ease),background var(--t) var(--ease),border-color var(--t) var(--ease),color var(--t) var(--ease),box-shadow var(--t) var(--ease);
}
.btn--primary{background:var(--cyan);color:var(--deep);}
.btn--primary:hover{background:#3FE6DA;color:var(--deep);transform:translateY(-2px);box-shadow:0 14px 24px -18px rgba(35,211,199,.95);}
.btn--signal{background:var(--orange);color:#20120A;}
.btn--signal:hover{background:#FFA063;color:#20120A;transform:translateY(-2px);box-shadow:0 14px 24px -18px rgba(255,138,61,.95);}
.btn--ghost{background:transparent;border-color:rgba(174,187,199,.5);color:var(--paper);}
.btn--ghost:hover{border-color:var(--cyan);color:var(--cyan);transform:translateY(-2px);}

/* ---------- tags & status ---------- */
.tag{
  display:inline-flex;
  align-items:center;
  gap:7px;
  padding:5px 11px;
  border:1px solid rgba(174,187,199,.4);
  border-radius:999px;
  background:rgba(19,42,61,.6);
  color:var(--mist);
  font-family:var(--font-mono);
  font-size:.72rem;
  letter-spacing:.08em;
}
.tag--cyan{color:var(--cyan);border-color:rgba(35,211,199,.5);background:rgba(35,211,199,.1);}
.tag--orange{color:var(--orange);border-color:rgba(255,138,61,.5);background:rgba(255,138,61,.1);}
.tag--violet{color:var(--violet);border-color:rgba(122,108,255,.5);background:rgba(122,108,255,.12);}

.status-dot{
  display:inline-block;
  width:7px;
  height:7px;
  border-radius:50%;
  background:var(--cyan);
  vertical-align:middle;
}
.status-dot--orange{background:var(--orange);}
.status-dot--violet{background:var(--violet);}

/* ---------- breadcrumbs ---------- */
.breadcrumbs{
  margin:0 0 clamp(18px,2.4vw,28px);
  font-family:var(--font-mono);
  font-size:.76rem;
  letter-spacing:.06em;
  color:var(--slate);
}
.breadcrumbs ol{display:flex;flex-wrap:wrap;align-items:center;gap:6px;}
.breadcrumbs li{display:inline-flex;align-items:center;gap:6px;}
.breadcrumbs li + li::before{content:"/";color:var(--slate);}
.breadcrumbs a{color:var(--mist);text-decoration:none;}
.breadcrumbs a:hover{color:var(--cyan);}

/* ---------- media containers ---------- */
.media{
  position:relative;
  display:block;
  overflow:hidden;
  border:1px solid rgba(174,187,199,.22);
  border-radius:var(--r-md) var(--r-sm) var(--r-md) var(--r-sm);
  background:
    linear-gradient(135deg,rgba(35,211,199,.16),rgba(122,108,255,.12) 46%,rgba(255,138,61,.12)),
    var(--ink-2);
}
.media__img{display:block;width:100%;height:100%;object-fit:cover;}
.media--16x9{aspect-ratio:16 / 9;}
.media--4x3{aspect-ratio:4 / 3;}
.media--3x2{aspect-ratio:3 / 2;}
.media--1x1{aspect-ratio:1 / 1;}
.media--grid::after{
  content:"";
  position:absolute;
  inset:0;
  pointer-events:none;
  background-image:
    linear-gradient(rgba(174,187,199,.16) 1px,transparent 1px),
    linear-gradient(90deg,rgba(174,187,199,.16) 1px,transparent 1px);
  background-size:32px 32px;
}
.media__label{
  position:absolute;
  left:14px;
  bottom:14px;
  padding:5px 10px;
  border:1px solid rgba(35,211,199,.4);
  border-radius:var(--r-sm) 12px var(--r-sm) 12px;
  background:rgba(6,19,30,.74);
  color:var(--paper);
  font-family:var(--font-mono);
  font-size:.7rem;
  letter-spacing:.12em;
}

/* ---------- skip link ---------- */
.skip-link{
  position:absolute;
  left:clamp(12px,3vw,32px);
  top:-120px;
  z-index:200;
  padding:12px 18px;
  border-radius:var(--r-sm) var(--r-md) var(--r-sm) var(--r-md);
  background:var(--cyan);
  color:var(--deep);
  font-family:var(--font-display);
  font-weight:700;
  text-decoration:none;
  transition:top var(--t) var(--ease);
}
.skip-link:focus{top:12px;color:var(--deep);}

/* ---------- header ---------- */
.site-header{
  position:sticky;
  top:0;
  z-index:80;
  background:linear-gradient(180deg,rgba(6,19,30,.78),rgba(6,19,30,0));
  border-bottom:1px solid rgba(243,247,250,.1);
  transition:background var(--t) var(--ease),border-color var(--t) var(--ease),box-shadow var(--t) var(--ease);
}
.site-header[data-state="solid"]{
  background:rgba(11,27,43,.96);
  border-bottom-color:rgba(35,211,199,.34);
  box-shadow:0 16px 34px -28px rgba(6,19,30,.95);
}
.site-header[data-open="true"]{
  background:rgba(6,19,30,.98);
  border-bottom-color:rgba(35,211,199,.34);
}

.header-inner{
  display:flex;
  align-items:center;
  gap:clamp(14px,2.6vw,36px);
  min-height:var(--header-h);
  padding-block:8px;
}

.brand{
  display:inline-flex;
  align-items:center;
  gap:12px;
  flex:0 0 auto;
  text-decoration:none;
  color:var(--paper);
}
.brand__mark{
  padding:6px 10px;
  border:1px solid rgba(35,211,199,.55);
  border-radius:var(--r-sm) var(--r-md) var(--r-sm) var(--r-md);
  background:rgba(35,211,199,.08);
  color:var(--cyan);
  font-family:var(--font-mono);
  font-weight:700;
  font-size:1rem;
  letter-spacing:.06em;
  transition:background var(--t) var(--ease),border-color var(--t) var(--ease);
}
.brand:hover .brand__mark{background:rgba(35,211,199,.2);border-color:var(--cyan);}
.brand__meta{display:flex;flex-direction:column;line-height:1.2;}
.brand__name{font-family:var(--font-display);font-weight:700;font-size:1.02rem;letter-spacing:-.01em;color:var(--paper);}
.brand__sub{font-family:var(--font-mono);font-size:.68rem;letter-spacing:.14em;color:var(--slate);}

.header-tools{
  display:flex;
  align-items:center;
  gap:clamp(10px,1.6vw,22px);
  margin-left:auto;
  flex:0 0 auto;
}

.call-sign{
  display:inline-flex;
  align-items:center;
  gap:8px;
  margin:0;
  font-family:var(--font-mono);
  font-size:.76rem;
  letter-spacing:.12em;
  color:var(--mist);
}
.call-sign__dot{
  width:7px;
  height:7px;
  border-radius:50%;
  background:var(--cyan);
  box-shadow:0 0 0 3px rgba(35,211,199,.16);
}
.call-sign__text{white-space:nowrap;}

.header-cta{
  display:inline-flex;
  align-items:center;
  gap:8px;
  padding:10px 16px;
  border-radius:var(--r-sm) var(--r-md) var(--r-sm) var(--r-md);
  background:var(--cyan);
  color:var(--deep);
  font-family:var(--font-display);
  font-weight:700;
  font-size:.86rem;
  text-decoration:none;
  white-space:nowrap;
  transition:background var(--t) var(--ease),transform var(--t) var(--ease),box-shadow var(--t) var(--ease);
}
.header-cta:hover{
  background:#3FE6DA;
  color:var(--deep);
  transform:translateY(-1px);
  box-shadow:0 12px 22px -16px rgba(35,211,199,.95);
}

/* ---------- nav ---------- */
.site-nav{
  position:absolute;
  top:100%;
  left:0;
  right:0;
  max-height:calc(100vh - var(--header-h));
  overflow-y:auto;
  padding:8px 0 20px;
  background:rgba(6,19,30,.98);
  border-top:1px solid rgba(35,211,199,.24);
  border-bottom:1px solid rgba(35,211,199,.2);
  opacity:0;
  visibility:hidden;
  transform:translateY(-8px);
  transition:opacity var(--t) var(--ease),transform var(--t) var(--ease),visibility var(--t) var(--ease);
}
.site-header[data-open="true"] .site-nav{
  opacity:1;
  visibility:visible;
  transform:none;
}

.nav-list{
  display:flex;
  flex-direction:column;
  padding-inline:var(--gutter);
}
.nav-item{display:block;}

.nav-link{
  position:relative;
  display:flex;
  align-items:baseline;
  gap:12px;
  padding:15px 0;
  border-bottom:1px solid rgba(174,187,199,.13);
  color:rgba(243,247,250,.88);
  font-size:.98rem;
  text-decoration:none;
  transition:color var(--t) var(--ease);
}
.nav-link__num{
  font-family:var(--font-mono);
  font-size:.7rem;
  letter-spacing:.1em;
  color:var(--slate);
  transition:color var(--t) var(--ease);
}
.nav-link__text{flex:1 1 auto;}
.nav-link:hover{color:var(--paper);}
.nav-link:hover .nav-link__num{color:var(--cyan);}
.nav-link[aria-current="page"]{color:var(--cyan);}
.nav-link[aria-current="page"] .nav-link__num{color:var(--orange);}

/* ---------- nav toggle ---------- */
.nav-toggle{
  display:inline-flex;
  align-items:center;
  gap:9px;
  padding:9px 12px;
  border:1px solid rgba(174,187,199,.4);
  border-radius:var(--r-sm) 12px var(--r-sm) 12px;
  background:transparent;
  color:var(--paper);
  font-family:var(--font-mono);
  font-size:.76rem;
  letter-spacing:.12em;
  cursor:pointer;
  transition:border-color var(--t) var(--ease),color var(--t) var(--ease),background var(--t) var(--ease);
}
.nav-toggle:hover{border-color:var(--cyan);color:var(--cyan);background:rgba(35,211,199,.08);}
.nav-toggle__label{white-space:nowrap;}
.nav-toggle__bars{display:inline-flex;flex-direction:column;gap:3px;width:16px;}
.nav-toggle__bars i{
  display:block;
  height:1.5px;
  width:100%;
  background:currentColor;
  transition:transform var(--t) var(--ease),opacity var(--t) var(--ease);
}
.site-header[data-open="true"] .nav-toggle__bars i:nth-child(1){transform:translateY(4.5px) rotate(45deg);}
.site-header[data-open="true"] .nav-toggle__bars i:nth-child(2){opacity:0;}
.site-header[data-open="true"] .nav-toggle__bars i:nth-child(3){transform:translateY(-4.5px) rotate(-45deg);}

/* ---------- scroll rail ---------- */
.scroll-rail{
  position:absolute;
  left:0;
  right:0;
  bottom:-1px;
  height:2px;
  overflow:hidden;
  background:rgba(174,187,199,.14);
}
.scroll-rail__bar{
  display:block;
  height:100%;
  width:100%;
  transform:scaleX(0);
  transform-origin:0 50%;
  background:linear-gradient(90deg,var(--cyan),var(--violet) 62%,var(--orange));
  transition:transform 100ms linear;
}

/* ---------- footer ---------- */
.site-footer{
  border-top:1px solid rgba(35,211,199,.22);
  background:var(--deep);
  color:var(--mist);
}
.footer-top{
  display:flex;
  flex-direction:column;
  gap:clamp(28px,4vw,52px);
  padding-block:clamp(44px,6vw,82px);
}
.footer-brand__mark{
  margin:0 0 12px;
  font-family:var(--font-display);
  font-weight:800;
  font-size:1.36rem;
  letter-spacing:-.01em;
  color:var(--paper);
}
.footer-brand__mark .mono{color:var(--cyan);}
.footer-brand__note{
  margin:0;
  max-width:48ch;
  font-size:.94rem;
  line-height:1.78;
  color:var(--mist);
}

.footer-grid{
  display:grid;
  grid-template-columns:repeat(2,minmax(0,1fr));
  gap:clamp(22px,3vw,42px);
}
.footer-col__title{
  margin:0 0 14px;
  font-family:var(--font-mono);
  font-size:.72rem;
  font-weight:700;
  letter-spacing:.16em;
  color:var(--cyan);
  line-height:1.4;
}
.footer-links{display:flex;flex-direction:column;gap:10px;}
.footer-link{
  display:inline-block;
  padding-bottom:2px;
  border-bottom:1px solid transparent;
  color:var(--mist);
  font-size:.92rem;
  text-decoration:none;
  transition:color var(--t) var(--ease),border-color var(--t) var(--ease);
}
.footer-link:hover{color:var(--paper);border-bottom-color:var(--cyan);}

.footer-contact{display:flex;gap:10px;margin:0 0 10px;font-size:.9rem;line-height:1.6;}
.footer-contact__key{
  flex:0 0 auto;
  padding-top:2px;
  font-family:var(--font-mono);
  font-size:.72rem;
  letter-spacing:.1em;
  color:var(--slate);
}
.footer-contact__val{
  font-family:var(--font-mono);
  font-size:.86rem;
  color:var(--paper);
  word-break:break-word;
}
.footer-contact--address .footer-contact__val{
  font-family:var(--font-body);
  font-size:.9rem;
  line-height:1.65;
}
.footer-note{
  margin:14px 0 0;
  padding-left:12px;
  border-left:2px solid var(--orange);
  font-size:.82rem;
  line-height:1.7;
  color:var(--slate);
}

.footer-bottom{
  border-top:1px solid rgba(174,187,199,.16);
  background:rgba(11,27,43,.62);
}
.footer-bottom__inner{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  justify-content:space-between;
  gap:10px 26px;
  padding-block:18px;
}
.footer-legal,.footer-fixed{
  margin:0;
  font-family:var(--font-mono);
  font-size:.76rem;
  letter-spacing:.06em;
  color:var(--slate);
}
.footer-fixed{color:var(--mist);}

/* ---------- motion preference ---------- */
@media (prefers-reduced-motion: no-preference){
  .call-sign__dot{animation:signal-pulse 2.8s var(--ease) infinite;}
}
@keyframes signal-pulse{
  0%,100%{opacity:1;}
  50%{opacity:.4;}
}

/* ---------- responsive ---------- */
@media (max-width:899px){
  html[data-nav-open="true"],
  html[data-nav-open="true"] body{overflow:hidden;}
}

@media (min-width:900px){
  .site-nav{
    position:static;
    max-height:none;
    overflow:visible;
    padding:0;
    margin-left:auto;
    background:transparent;
    border:0;
    opacity:1;
    visibility:visible;
    transform:none;
  }
  .nav-list{
    flex-direction:row;
    align-items:center;
    gap:clamp(6px,1.5vw,26px);
    padding-inline:0;
  }
  .nav-link{
    padding:8px 0;
    border-bottom:0;
    font-size:.93rem;
    gap:7px;
  }
  .nav-link::after{
    content:"";
    position:absolute;
    left:0;
    right:0;
    bottom:0;
    height:2px;
    background:var(--cyan);
    transform:scaleX(0);
    transform-origin:0 50%;
    transition:transform var(--t) var(--ease),background var(--t) var(--ease);
  }
  .nav-link:hover::after{transform:scaleX(1);}
  .nav-link[aria-current="page"]::after{transform:scaleX(1);background:var(--orange);}
  .nav-toggle{display:none;}
  .footer-grid{grid-template-columns:repeat(4,minmax(0,1fr));}
  .footer-top{
    display:grid;
    grid-template-columns:minmax(240px,.85fr) 2.4fr;
    align-items:start;
  }
}

@media (max-width:900px){
  .span-4,.span-5,.span-6,.span-7,.span-8{grid-column:span 12;}
}

@media (max-width:760px){
  .call-sign{display:none;}
}

@media (max-width:560px){
  .header-cta{display:none;}
  .brand__sub{display:none;}
  .footer-bottom__inner{flex-direction:column;align-items:flex-start;}
}

@media (prefers-reduced-motion: reduce){
  html{scroll-behavior:auto;}
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
  }
}