:root{
  --ink:#07110E;
  --panel:#0E2A22;
  --moss:#1B4A3A;
  --cyan:#38F2D0;
  --cyan-soft:#A7FFF0;
  --orange:#FF7A1A;
  --paper:#F3F6EF;
  --muted:#8FA39A;
  --white:#FFFFFF;
  --red:#E5484D;

  --rail-w:92px;
  --bar-h:60px;
  --edge:clamp(18px,4vw,56px);
  --max-w:1280px;

  --font-display:"Noto Sans SC","Source Han Sans SC","PingFang SC","Microsoft YaHei","Heiti SC",sans-serif;
  --font-serif:"Noto Serif SC","Source Han Serif SC","Songti SC","STSong",serif;
  --font-body:"Noto Sans SC","Source Han Sans SC","PingFang SC","Microsoft YaHei",system-ui,-apple-system,sans-serif;
  --font-mono:"Roboto Mono","IBM Plex Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;

  --ease:160ms cubic-bezier(.22,.61,.36,1);
}

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

html{
  -webkit-text-size-adjust:100%;
  text-size-adjust:100%;
  scroll-behavior:smooth;
}

body{
  margin:0;
  min-block-size:100vh;
  background:var(--ink);
  color:var(--paper);
  font-family:var(--font-body);
  font-size:16px;
  font-weight:400;
  line-height:1.72;
  letter-spacing:.01em;
  -webkit-font-smoothing:antialiased;
  -moz-osx-font-smoothing:grayscale;
}

h1,h2,h3,h4{
  margin:0;
  font-family:var(--font-display);
  font-weight:800;
  line-height:1.18;
  letter-spacing:-.02em;
  color:var(--white);
}

p{margin:0}
ul,ol{margin:0;padding:0;list-style:none}
img,svg{max-inline-size:100%}
img{block-size:auto}
button{font:inherit;color:inherit}

a{
  color:var(--cyan);
  text-decoration:none;
  transition:color var(--ease),border-color var(--ease),background-color var(--ease);
}
a:hover{color:var(--cyan-soft)}

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

::selection{background:var(--cyan);color:var(--ink)}

#main-content{scroll-margin-block-start:calc(var(--bar-h) + 12px)}

/* ---------- skip link ---------- */
.skip-link{
  position:fixed;
  inset-block-start:8px;
  inset-inline-start:8px;
  z-index:300;
  padding:10px 16px;
  background:var(--cyan);
  color:var(--ink);
  font-family:var(--font-body);
  font-size:13px;
  font-weight:700;
  letter-spacing:.06em;
  transform:translateY(-180%);
  transition:transform var(--ease);
}
.skip-link:focus{transform:translateY(0);color:var(--ink)}

/* ---------- header : mobile bar ---------- */
.site-header{
  position:sticky;
  inset-block-start:0;
  z-index:80;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:12px;
  min-block-size:var(--bar-h);
  padding:0 16px;
  background:var(--panel);
  border-block-end:1px solid var(--moss);
}

.brand{
  display:inline-flex;
  align-items:baseline;
  gap:8px;
  padding-block:8px;
  color:var(--white);
  text-decoration:none;
}
.brand__mark{
  font-family:var(--font-display);
  font-size:20px;
  font-weight:900;
  line-height:1;
  letter-spacing:-.04em;
  color:var(--cyan);
  transition:color var(--ease);
}
.brand__text{
  font-family:var(--font-display);
  font-size:13px;
  font-weight:700;
  line-height:1;
  letter-spacing:.26em;
  text-indent:.26em;
  color:var(--white);
}
.brand:hover .brand__mark,
.brand:focus-visible .brand__mark{color:var(--cyan-soft)}

.nav-toggle{
  display:inline-flex;
  align-items:center;
  gap:9px;
  min-block-size:40px;
  padding:9px 12px;
  background:transparent;
  border:1px solid var(--moss);
  color:var(--paper);
  font-size:13px;
  font-weight:500;
  letter-spacing:.16em;
  cursor:pointer;
  transition:color var(--ease),border-color var(--ease),background-color var(--ease);
}
.nav-toggle:hover,
.nav-toggle:focus-visible{color:var(--cyan);border-color:var(--cyan)}
.nav-toggle__bars{
  display:inline-flex;
  flex-direction:column;
  justify-content:center;
  gap:4px;
  inline-size:16px;
}
.nav-toggle__bars span{
  display:block;
  block-size:1px;
  background:currentColor;
  transition:transform var(--ease),opacity var(--ease);
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(1){transform:translateY(5px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(2){opacity:0}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(3){transform:translateY(-5px) rotate(-45deg)}

/* ---------- header : nav (mobile drawer) ---------- */
.site-nav{
  position:fixed;
  inset-inline:0;
  inset-block-start:var(--bar-h);
  z-index:79;
  max-block-size:calc(100vh - var(--bar-h));
  max-block-size:calc(100dvh - var(--bar-h));
  overflow-y:auto;
  padding:6px 16px 24px;
  background:var(--ink);
  border-block-end:1px solid var(--moss);
  opacity:0;
  visibility:hidden;
  transform:translateY(-8px);
  transition:opacity var(--ease),transform var(--ease),visibility var(--ease);
}
.site-nav[data-open]{
  opacity:1;
  visibility:visible;
  transform:translateY(0);
}

.site-nav__list{display:flex;flex-direction:column}

.site-nav__link{
  display:block;
  padding:14px 6px;
  border-inline-start:3px solid transparent;
  border-block-end:1px solid rgba(27,74,58,.72);
  color:var(--paper);
  font-family:var(--font-display);
  font-size:16px;
  font-weight:600;
  letter-spacing:.1em;
  transition:color var(--ease),border-color var(--ease),padding-inline-start var(--ease);
}
.site-nav__link:hover,
.site-nav__link:focus-visible{
  color:var(--cyan);
  padding-inline-start:14px;
}
.site-nav__link[aria-current="page"]{
  color:var(--cyan);
  border-inline-start-color:var(--cyan);
  padding-inline-start:14px;
}

.nav-status{
  margin-block-start:16px;
  padding-block-start:16px;
  border-block-start:1px solid var(--moss);
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.06em;
  line-height:1.7;
  color:var(--muted);
}

/* ---------- header : desktop rail ---------- */
@media (min-width:1024px){
  body{padding-inline-start:var(--rail-w)}

  #main-content{scroll-margin-block-start:12px}

  .skip-link{inset-inline-start:calc(var(--rail-w) + 8px)}

  .site-header{
    position:fixed;
    inset-block:0;
    inset-inline-start:0;
    inset-inline-end:auto;
    inline-size:var(--rail-w);
    min-block-size:0;
    flex-direction:column;
    align-items:center;
    justify-content:flex-start;
    gap:0;
    padding:20px 0 14px;
    border-block-end:0;
    border-inline-end:1px solid var(--moss);
    overflow-y:auto;
    scrollbar-width:none;
  }
  .site-header::-webkit-scrollbar{inline-size:0;block-size:0}

  .brand{
    flex-direction:column;
    align-items:center;
    gap:10px;
    inline-size:100%;
    padding:0 0 20px;
    border-block-end:1px solid var(--moss);
  }
  .brand__mark{font-size:26px}
  .brand__text{font-size:11px;letter-spacing:.34em;text-indent:.34em}

  .nav-toggle{display:none}

  .site-nav{
    position:static;
    inset:auto;
    z-index:auto;
    flex:1 1 auto;
    inline-size:100%;
    max-block-size:none;
    overflow:visible;
    padding:26px 0 10px;
    background:transparent;
    border-block-end:0;
    opacity:1;
    visibility:visible;
    transform:none;
    transition:none;
    display:flex;
    justify-content:center;
  }

  .site-nav__list{align-items:center;gap:8px}

  .site-nav__link{
    position:relative;
    writing-mode:vertical-rl;
    padding-block:14px;
    padding-inline:0;
    border:0;
    color:var(--muted);
    font-size:15px;
    font-weight:600;
    letter-spacing:.24em;
    line-height:1;
  }
  .site-nav__link:hover,
  .site-nav__link:focus-visible{
    color:var(--cyan-soft);
    padding-inline-start:0;
  }
  .site-nav__link[aria-current="page"]{
    color:var(--cyan);
    padding-inline-start:0;
    border-inline-start-color:transparent;
  }
  .site-nav__link[aria-current="page"]::before{
    content:"";
    position:absolute;
    inset-block-start:2px;
    inset-inline-start:50%;
    margin-inline-start:-7px;
    inline-size:14px;
    block-size:2px;
    background:var(--cyan);
  }

  .nav-status{display:none}
}

/* ---------- footer ---------- */
.site-footer{
  margin-block-start:clamp(32px,6vw,80px);
  padding:clamp(36px,6vw,72px) var(--edge) 0;
  background:var(--panel);
  border-block-start:1px solid var(--moss);
  color:var(--paper);
}

.footer-inner{
  max-inline-size:var(--max-w);
  margin-inline:auto;
  display:grid;
  grid-template-columns:minmax(0,1fr);
  gap:clamp(26px,4vw,44px);
  padding-block-end:clamp(26px,4vw,44px);
}

.footer-brand__logo{
  display:inline-block;
  font-family:var(--font-display);
  font-size:24px;
  font-weight:900;
  line-height:1.1;
  letter-spacing:-.02em;
  color:var(--white);
}
.footer-brand__ng{color:var(--cyan)}
.footer-brand__logo:hover{color:var(--white)}
.footer-brand__logo:hover .footer-brand__ng{color:var(--cyan-soft)}

.footer-brand__line{
  margin-block-start:14px;
  max-inline-size:22em;
  font-family:var(--font-serif);
  font-size:15px;
  line-height:1.7;
  color:var(--muted);
}

.footer-col__heading{
  margin-block-end:14px;
  padding-block-end:10px;
  border-block-end:1px solid var(--moss);
  font-family:var(--font-mono);
  font-size:11px;
  font-weight:500;
  letter-spacing:.22em;
  color:var(--cyan);
}

.footer-col__list{
  display:flex;
  flex-direction:column;
  gap:10px;
}

.footer-col__link{
  display:inline-block;
  padding-block:2px;
  border-block-end:1px solid transparent;
  color:var(--paper);
  font-size:14.5px;
  transition:color var(--ease),border-color var(--ease);
}
.footer-col__link:hover,
.footer-col__link:focus-visible{
  color:var(--cyan);
  border-block-end-color:var(--cyan);
}

.footer-contact__link{
  display:inline-block;
  max-inline-size:100%;
  font-family:var(--font-mono);
  font-size:13.5px;
  letter-spacing:.02em;
  overflow-wrap:anywhere;
  color:var(--paper);
  border-block-end:1px solid rgba(56,242,208,.3);
  transition:color var(--ease),border-color var(--ease);
}
.footer-contact__link:hover,
.footer-contact__link:focus-visible{color:var(--cyan);border-block-end-color:var(--cyan)}

.footer-contact__address{
  display:inline-block;
  font-size:14px;
  line-height:1.6;
  color:var(--muted);
}

.footer-contact__note{
  margin-block-start:14px;
  max-inline-size:30em;
  padding-inline-start:12px;
  border-inline-start:2px solid var(--moss);
  font-size:12.5px;
  line-height:1.72;
  color:var(--muted);
}

.footer-bottom{
  max-inline-size:var(--max-w);
  margin-inline:auto;
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  justify-content:space-between;
  gap:12px 20px;
  padding-block:18px 26px;
  border-block-start:1px solid var(--moss);
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.04em;
  color:var(--muted);
}
.footer-bottom__copy{margin:0}

.footer-legal{
  display:flex;
  flex-wrap:wrap;
  gap:6px 18px;
}
.footer-legal a{
  color:var(--muted);
  border-block-end:1px solid transparent;
}
.footer-legal a:hover,
.footer-legal a:focus-visible{
  color:var(--cyan);
  border-block-end-color:var(--cyan);
}

.footer-icp{color:var(--muted)}

@media (min-width:640px){
  .footer-inner{grid-template-columns:repeat(2,minmax(0,1fr))}
  .footer-brand{grid-column:1 / -1}
}
@media (min-width:1024px){
  .footer-inner{grid-template-columns:minmax(0,1.5fr) minmax(0,1fr) minmax(0,1fr) minmax(0,1.6fr)}
  .footer-brand{grid-column:auto}
}

/* ---------- layout ---------- */
.container{
  inline-size:100%;
  max-inline-size:var(--max-w);
  margin-inline:auto;
  padding-inline:var(--edge);
}
.container--narrow{max-inline-size:860px}

.section{padding-block:clamp(32px,5.5vw,72px)}

.grid{display:grid;gap:clamp(16px,2.4vw,28px)}
.grid--12{grid-template-columns:repeat(4,minmax(0,1fr))}
@media (min-width:768px){.grid--12{grid-template-columns:repeat(6,minmax(0,1fr))}}
@media (min-width:1024px){.grid--12{grid-template-columns:repeat(12,minmax(0,1fr))}}

.rule{
  border:0;
  border-block-start:1px solid var(--moss);
  margin-block:clamp(20px,3vw,36px);
}

/* ---------- type helpers ---------- */
.eyebrow{
  display:inline-flex;
  align-items:center;
  gap:10px;
  font-family:var(--font-mono);
  font-size:11px;
  font-weight:500;
  letter-spacing:.24em;
  line-height:1.4;
  color:var(--cyan);
}
.eyebrow::before{
  content:"";
  inline-size:22px;
  block-size:1px;
  background:var(--cyan);
}

.mono{
  font-family:var(--font-mono);
  font-variant-numeric:tabular-nums;
  letter-spacing:.02em;
}

/* ---------- buttons ---------- */
.btn{
  --btn-bg:transparent;
  --btn-fg:var(--paper);
  --btn-bd:var(--moss);
  display:inline-flex;
  align-items:center;
  gap:10px;
  padding:13px 22px;
  background:var(--btn-bg);
  color:var(--btn-fg);
  border:1px solid var(--btn-bd);
  font-family:var(--font-body);
  font-size:14px;
  font-weight:500;
  letter-spacing:.08em;
  line-height:1.2;
  text-decoration:none;
  cursor:pointer;
  transition:background-color var(--ease),color var(--ease),border-color var(--ease),transform var(--ease);
}
.btn:hover,
.btn:focus-visible{
  transform:translateY(-2px);
  color:var(--btn-fg);
}
.btn--solid{
  --btn-bg:var(--cyan);
  --btn-fg:var(--ink);
  --btn-bd:var(--cyan);
  font-weight:700;
}
.btn--solid:hover,
.btn--solid:focus-visible{
  --btn-bg:var(--cyan-soft);
  --btn-bd:var(--cyan-soft);
}
.btn--ghost{--btn-fg:var(--paper)}
.btn--ghost:hover,
.btn--ghost:focus-visible{
  --btn-fg:var(--cyan);
  --btn-bd:var(--cyan);
}
.btn--orange{
  --btn-bg:var(--orange);
  --btn-fg:var(--ink);
  --btn-bd:var(--orange);
  font-weight:700;
}
.btn--orange:hover,
.btn--orange:focus-visible{
  --btn-bg:#FFA05C;
  --btn-bd:#FFA05C;
}

/* ---------- breadcrumb ---------- */
.breadcrumb{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:8px;
  margin-block-end:clamp(18px,3vw,28px);
  font-family:var(--font-mono);
  font-size:11.5px;
  letter-spacing:.1em;
  color:var(--muted);
}
.breadcrumb li{display:flex;align-items:center;gap:8px}
.breadcrumb li + li::before{
  content:"/";
  color:var(--moss);
}
.breadcrumb a{color:var(--muted)}
.breadcrumb a:hover,
.breadcrumb a:focus-visible{color:var(--cyan)}
.breadcrumb [aria-current="page"]{color:var(--paper)}

/* ---------- prose ---------- */
.prose{
  max-inline-size:38em;
  font-size:16.5px;
  line-height:1.8;
  color:var(--paper);
}
.prose > * + *{margin-block-start:1.1em}
.prose p{margin:0}
.prose h2{
  margin-block-start:2.1em;
  font-size:clamp(22px,2.6vw,30px);
  letter-spacing:-.02em;
  color:var(--white);
}
.prose h3{
  margin-block-start:1.8em;
  font-size:18px;
  letter-spacing:0;
  color:var(--white);
}
.prose ul,
.prose ol{padding-inline-start:1.3em}
.prose ul{list-style:square}
.prose ol{list-style:decimal}
.prose li + li{margin-block-start:.5em}
.prose li::marker{color:var(--cyan)}
.prose strong{font-weight:700;color:var(--white)}
.prose a{
  color:var(--cyan);
  border-block-end:1px solid rgba(56,242,208,.4);
}
.prose a:hover,
.prose a:focus-visible{border-block-end-color:var(--cyan)}
.prose hr{
  border:0;
  border-block-start:1px solid var(--moss);
  margin-block:2.2em;
}
.prose code{
  font-family:var(--font-mono);
  font-size:.92em;
  padding:1px 6px;
  background:var(--panel);
  border:1px solid var(--moss);
  color:var(--cyan-soft);
}

/* ---------- panel ---------- */
.panel{
  background:var(--panel);
  border:1px solid var(--moss);
  padding:clamp(16px,2.2vw,26px);
}
.panel__head{
  display:flex;
  align-items:baseline;
  justify-content:space-between;
  gap:12px;
  margin-block-end:14px;
  padding-block-end:12px;
  border-block-end:1px solid var(--moss);
}
.panel__title{
  font-family:var(--font-display);
  font-size:13px;
  font-weight:700;
  letter-spacing:.14em;
  color:var(--white);
}

/* ---------- responsive media frame ---------- */
.media{
  position:relative;
  display:block;
  inline-size:100%;
  overflow:hidden;
  aspect-ratio:16 / 9;
  border:1px solid var(--moss);
  background-color:var(--panel);
  background-image:
    linear-gradient(to right,rgba(56,242,208,.10) 1px,transparent 1px),
    linear-gradient(to bottom,rgba(56,242,208,.10) 1px,transparent 1px);
  background-size:32px 32px,32px 32px;
}
.media > img,
.media > svg{
  display:block;
  inline-size:100%;
  block-size:100%;
  object-fit:cover;
}
.media--wide{aspect-ratio:21 / 9}
.media--square{aspect-ratio:1 / 1}
.media--tall{aspect-ratio:3 / 4}
@media (min-width:768px){
  .cut-top{clip-path:polygon(0 6%,100% 0,100% 100%,0 100%)}
  .cut-bottom{clip-path:polygon(0 0,100% 0,100% 94%,0 100%)}
}

/* ---------- paper surface ---------- */
.surface-paper{
  background:var(--paper);
  color:#12241E;
}
.surface-paper h2,
.surface-paper h3,
.surface-paper h4,
.surface-paper strong{color:var(--ink)}
.surface-paper a{color:#0B5B49}
.surface-paper a:hover{color:#0E7A63}
.surface-paper .prose{color:#22423A}
.surface-paper .prose h2,
.surface-paper .prose h3{color:var(--ink)}
.surface-paper .rule,
.surface-paper .prose hr{border-block-start-color:#CBD8CC}

/* ---------- scroll meter ---------- */
.scroll-meter{
  position:fixed;
  inset-block-start:var(--bar-h);
  inset-inline:0;
  z-index:78;
  block-size:2px;
  background:rgba(27,74,58,.6);
  pointer-events:none;
}
.scroll-meter__bar{
  inline-size:100%;
  block-size:100%;
  transform:scaleX(0);
  transform-origin:0 50%;
  background:linear-gradient(90deg,var(--cyan),var(--orange));
}
@media (min-width:1024px){
  .scroll-meter{
    inset-block-start:0;
    inset-inline-start:var(--rail-w);
    block-size:3px;
  }
}

/* ---------- motion preferences ---------- */
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,
  *::before,
  *::after{
    animation-duration:.01ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.01ms !important;
    transition-delay:0ms !important;
    scroll-behavior:auto !important;
  }
  .btn:hover,
  .btn:focus-visible{transform:none}
}