:root{
  --ink-950:#06111F;
  --ink-850:#0C1B2E;
  --slate-600:#2A3B52;
  --fog-300:#A9B8CC;
  --paper-050:#F4F7FB;
  --cyan-400:#35E6D4;
  --cyan-600:#0FA8A0;
  --amber-400:#FFB25E;
  --amber-650:#C97A2B;
  --mint-100:#DFFBF6;
  --ink-900:#07111C;
  --mist-100:#E8EEF5;

  --bg:var(--ink-950);
  --surface:var(--ink-850);
  --line:rgba(42,59,82,.85);
  --line-soft:rgba(42,59,82,.55);
  --text:var(--paper-050);
  --text-dim:var(--fog-300);
  --accent:var(--cyan-400);
  --accent-warm:var(--amber-400);

  --font-sans:"PingFang SC","Hiragino Sans GB","Noto Sans SC","Source Han Sans SC","Microsoft YaHei",system-ui,-apple-system,"Segoe UI",sans-serif;
  --font-mono:"JetBrains Mono","IBM Plex Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,"Courier New",monospace;

  --radius-s:12px;
  --radius-m:20px;
  --radius-l:28px;
  --radius-pill:999px;

  --container:1320px;
  --gutter:clamp(16px,4vw,40px);
  --header-h:76px;
  --ease:cubic-bezier(.22,.61,.36,1);
}

/* ---------- Reset ---------- */
*,*::before,*::after{box-sizing:border-box;}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth;}
body{
  margin:0;
  background:var(--bg);
  color:var(--text);
  font-family:var(--font-sans);
  font-size:16px;
  font-weight:400;
  line-height:1.75;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}
h1,h2,h3,h4,h5,h6,p,figure,blockquote,ul,ol,dl,dd{margin:0;}
ul,ol{padding:0;}
ul[class],ol[class]{list-style:none;}
a{color:inherit;text-decoration:none;}
img,svg,video{display:block;max-width:100%;}
button{font:inherit;color:inherit;background:none;border:0;padding:0;cursor:pointer;}
table{border-collapse:collapse;width:100%;}
:focus-visible{outline:2px solid var(--cyan-400);outline-offset:3px;border-radius:4px;}
::selection{background:var(--cyan-400);color:var(--ink-950);}

/* ---------- Typography utilities ---------- */
.mono{
  font-family:var(--font-mono);
  font-size:.7rem;
  letter-spacing:.12em;
  text-transform:uppercase;
  font-weight:500;
}
.eyebrow{
  display:inline-flex;
  align-items:center;
  gap:.65em;
  font-family:var(--font-mono);
  font-size:.7rem;
  letter-spacing:.18em;
  text-transform:uppercase;
  color:var(--cyan-400);
}
.eyebrow::before{content:"";width:26px;height:1px;background:currentColor;flex:none;}
.display{
  font-size:clamp(56px,8vw,120px);
  line-height:.92;
  letter-spacing:-.03em;
  font-weight:900;
}
.h2{
  font-size:clamp(30px,4vw,56px);
  line-height:1.05;
  letter-spacing:-.02em;
  font-weight:700;
}
.h3{
  font-size:clamp(20px,2.2vw,28px);
  line-height:1.2;
  letter-spacing:-.01em;
  font-weight:700;
}
.lead{
  font-size:clamp(16px,1.5vw,19px);
  line-height:1.75;
  color:var(--text-dim);
  max-width:44ch;
}
.index-num{
  font-family:var(--font-mono);
  font-size:clamp(28px,4vw,48px);
  line-height:1;
  font-weight:700;
  letter-spacing:.02em;
  color:var(--cyan-400);
}
.note-vertical{
  writing-mode:vertical-rl;
  font-family:var(--font-mono);
  font-size:.7rem;
  letter-spacing:.22em;
  color:var(--text-dim);
}
.rule{
  height:1px;
  border:0;
  background:linear-gradient(90deg,var(--slate-600),rgba(42,59,82,0));
  margin:0;
}

/* ---------- Layout ---------- */
.container{
  width:100%;
  max-width:var(--container);
  margin-inline:auto;
  padding-inline:var(--gutter);
}
.section{padding-block:clamp(56px,8vw,112px);}
.section--panel{background:var(--surface);}
.section--light{background:var(--paper-050);color:var(--ink-900);}
.section--light .lead,
.section--light .note-vertical{color:#4B5C72;}
.section--light .rule{background:linear-gradient(90deg,rgba(7,17,28,.24),rgba(7,17,28,0));}
.section-head{
  display:grid;
  gap:clamp(10px,1.6vw,18px);
  max-width:56ch;
  margin-bottom:clamp(28px,4vw,48px);
}
.grid-12{
  display:grid;
  grid-template-columns:repeat(12,minmax(0,1fr));
  gap:clamp(16px,2.4vw,32px);
}
.panel{
  background:var(--surface);
  border:1px solid var(--line);
  border-radius:var(--radius-l);
  padding:clamp(20px,3vw,36px);
}
.section--light .panel{
  background:#fff;
  border-color:rgba(7,17,28,.1);
}
@media (max-width:900px){
  .grid-12{grid-template-columns:repeat(6,minmax(0,1fr));}
}
@media (max-width:600px){
  .grid-12{grid-template-columns:repeat(2,minmax(0,1fr));}
}

/* ---------- Buttons ---------- */
.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:.6em;
  min-height:46px;
  padding:.7em 1.5em;
  border-radius:var(--radius-pill);
  border:1px solid transparent;
  font-size:.95rem;
  font-weight:500;
  line-height:1.2;
  transition:background-color .18s var(--ease),color .18s var(--ease),border-color .18s var(--ease),transform .18s var(--ease);
}
.btn--primary{background:var(--cyan-400);color:var(--ink-950);}
.btn--primary:hover{background:var(--mint-100);transform:translateY(-1px);}
.btn--ghost{border-color:rgba(53,230,212,.42);color:var(--cyan-400);}
.btn--ghost:hover{background:rgba(53,230,212,.1);border-color:var(--cyan-400);}
.btn--warm{background:var(--amber-400);color:var(--ink-900);}
.btn--warm:hover{background:#FFC98A;transform:translateY(-1px);}
.btn--quiet{border-color:var(--line);color:var(--text-dim);}
.btn--quiet:hover{color:var(--paper-050);border-color:var(--fog-300);}
.section--light .btn--quiet{border-color:rgba(7,17,28,.18);color:#3B4B60;}
.section--light .btn--quiet:hover{color:var(--ink-900);border-color:var(--ink-900);}

/* ---------- Pills ---------- */
.pill{
  display:inline-flex;
  align-items:center;
  gap:.5em;
  padding:.32em .85em;
  border-radius:var(--radius-pill);
  border:1px solid var(--line);
  font-family:var(--font-mono);
  font-size:.68rem;
  letter-spacing:.12em;
  text-transform:uppercase;
  color:var(--text-dim);
}
.pill--accent{border-color:rgba(53,230,212,.45);color:var(--cyan-400);}
.pill--warm{border-color:rgba(255,178,94,.45);color:var(--amber-400);}

/* ---------- Breadcrumb ---------- */
.breadcrumb{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:.55em;
  font-family:var(--font-mono);
  font-size:.7rem;
  letter-spacing:.1em;
  text-transform:uppercase;
  color:var(--text-dim);
}
.breadcrumb a{color:var(--text-dim);border-bottom:1px solid transparent;transition:color .18s var(--ease),border-color .18s var(--ease);}
.breadcrumb a:hover{color:var(--cyan-400);border-color:var(--cyan-600);}
.breadcrumb [aria-current="page"]{color:var(--paper-050);}
.breadcrumb-sep{color:var(--slate-600);}
.section--light .breadcrumb,
.section--light .breadcrumb a{color:#4B5C72;}

/* ---------- Image frames (page-stage placeholders) ---------- */
.img-frame{
  position:relative;
  isolation:isolate;
  overflow:hidden;
  border-radius:var(--radius-l);
  border:1px solid var(--line);
  background:
    radial-gradient(120% 90% at 18% 8%,rgba(53,230,212,.16),rgba(53,230,212,0) 60%),
    radial-gradient(110% 90% at 88% 92%,rgba(255,178,94,.14),rgba(255,178,94,0) 58%),
    var(--ink-850);
  aspect-ratio:16/10;
}
.img-frame::after{
  content:"";
  position:absolute;
  inset:0;
  background:repeating-linear-gradient(180deg,rgba(244,247,251,.06) 0 1px,rgba(244,247,251,0) 1px 4px);
  pointer-events:none;
  z-index:2;
}
.img-frame img{
  position:relative;
  z-index:1;
  width:100%;
  height:100%;
  object-fit:cover;
}
.img-frame--wide{aspect-ratio:21/9;}
.img-frame--tall{aspect-ratio:3/4;}
.img-frame--square{aspect-ratio:1/1;border-radius:var(--radius-m);}

/* ---------- Reveal ---------- */
.reveal{
  opacity:0;
  transform:translateY(12px);
  transition:opacity .4s var(--ease),transform .4s var(--ease);
  transition-delay:var(--reveal-delay,0ms);
}
.reveal[data-visible="true"]{opacity:1;transform:none;}

/* ---------- Skip link ---------- */
.skip-link{
  position:absolute;
  left:var(--gutter);
  top:-120px;
  z-index:140;
  display:inline-flex;
  align-items:center;
  padding:12px 22px;
  border-radius:var(--radius-pill);
  background:var(--cyan-400);
  color:var(--ink-950);
  font-weight:700;
  transition:top .2s var(--ease);
}
.skip-link:focus{top:12px;}

/* ---------- Site header ---------- */
.site-header{
  position:fixed;
  inset:0 0 auto 0;
  z-index:80;
  color:var(--paper-050);
  background:linear-gradient(180deg,rgba(6,17,31,.88),rgba(6,17,31,0));
  transition:background-color .28s var(--ease),box-shadow .28s var(--ease);
}
.site-header[data-scrolled="true"]{
  background:rgba(6,17,31,.96);
  box-shadow:0 1px 0 var(--line),0 22px 48px -34px rgba(0,0,0,.95);
  backdrop-filter:blur(12px);
  -webkit-backdrop-filter:blur(12px);
}
.header-inner{
  width:100%;
  max-width:var(--container);
  margin-inline:auto;
  padding-inline:var(--gutter);
  min-height:var(--header-h);
  display:grid;
  grid-template-columns:auto 1fr auto;
  align-items:center;
  gap:clamp(12px,2.4vw,40px);
}

/* Brand */
.brand{
  display:inline-flex;
  align-items:center;
  gap:12px;
  min-height:44px;
  color:var(--paper-050);
}
.brand-mark{
  flex:none;
  width:36px;
  height:36px;
  border-radius:var(--radius-pill);
  border:1px solid rgba(53,230,212,.4);
  background:radial-gradient(circle at 50% 50%,rgba(53,230,212,.2),rgba(53,230,212,0));
  display:grid;
  grid-auto-flow:column;
  align-items:center;
  justify-content:center;
  gap:3px;
}
.brand-mark-bar{
  display:block;
  width:3px;
  height:13px;
  border-radius:2px;
  background:var(--cyan-400);
}
.brand-mark-bar:nth-child(2){height:20px;background:var(--amber-400);}
.brand-mark-bar:nth-child(3){height:9px;}
.brand-text{display:flex;flex-direction:column;gap:2px;}
.brand-name{
  display:block;
  font-size:1.02rem;
  font-weight:700;
  line-height:1.15;
  letter-spacing:-.01em;
}
.brand-sub{
  display:block;
  font-size:.6rem;
  letter-spacing:.18em;
  color:var(--fog-300);
}

/* Nav */
.site-nav{
  display:flex;
  align-items:center;
  justify-content:center;
  min-width:0;
}
.nav-list{
  display:flex;
  align-items:center;
  gap:clamp(2px,1.1vw,16px);
  flex-wrap:nowrap;
}
.nav-item{flex:none;}
.nav-link{
  position:relative;
  display:inline-flex;
  align-items:center;
  min-height:44px;
  padding:0 10px;
  font-size:.92rem;
  line-height:1.2;
  color:var(--fog-300);
  white-space:nowrap;
  transition:color .18s var(--ease);
}
.nav-link::after{
  content:"";
  position:absolute;
  left:10px;
  right:10px;
  bottom:9px;
  height:1px;
  background:var(--cyan-400);
  transform:scaleX(0);
  transform-origin:0 50%;
  transition:transform .22s var(--ease);
}
.nav-link:hover{color:var(--paper-050);}
.nav-link:hover::after{transform:scaleX(1);}
.nav-link[aria-current="page"]{color:var(--paper-050);}
.nav-link[aria-current="page"]::after{transform:scaleX(1);background:var(--amber-400);}
.nav-note{display:none;}

/* Header tools */
.header-tools{
  display:flex;
  align-items:center;
  gap:clamp(6px,1.2vw,14px);
  justify-self:end;
}
.status-pill{
  display:inline-flex;
  align-items:center;
  gap:8px;
  min-height:38px;
  padding:0 14px;
  border-radius:var(--radius-pill);
  border:1px solid rgba(53,230,212,.35);
  background:rgba(53,230,212,.06);
  color:var(--cyan-400);
  font-family:var(--font-mono);
  font-size:.66rem;
  letter-spacing:.12em;
  white-space:nowrap;
  transition:background-color .18s var(--ease),border-color .18s var(--ease);
}
.status-pill:hover{background:rgba(53,230,212,.15);border-color:var(--cyan-400);}
.status-dot{
  width:6px;
  height:6px;
  flex:none;
  border-radius:50%;
  background:var(--cyan-400);
  box-shadow:0 0 0 3px rgba(53,230,212,.18);
}
.index-link{
  display:inline-flex;
  align-items:center;
  min-height:38px;
  padding:0 10px;
  font-size:.82rem;
  color:var(--fog-300);
  border-bottom:1px solid transparent;
  white-space:nowrap;
  transition:color .18s var(--ease),border-color .18s var(--ease);
}
.index-link:hover{color:var(--paper-050);border-color:var(--cyan-600);}

/* Mobile toggle */
.nav-toggle{
  display:none;
  align-items:center;
  justify-content:center;
  gap:8px;
  min-width:44px;
  min-height:44px;
  padding:0 12px;
  border-radius:var(--radius-pill);
  border:1px solid var(--line);
  color:var(--paper-050);
  transition:border-color .18s var(--ease),background-color .18s var(--ease);
}
.nav-toggle:hover{border-color:var(--cyan-400);background:rgba(53,230,212,.08);}
.nav-toggle-bars{display:flex;flex-direction:column;gap:5px;width:18px;}
.nav-toggle-bars span{display:block;height:1.5px;border-radius:2px;background:currentColor;transition:transform .24s var(--ease),opacity .24s var(--ease);}
.nav-toggle[aria-expanded="true"] .nav-toggle-bars span:first-child{transform:translateY(3.25px) rotate(45deg);}
.nav-toggle[aria-expanded="true"] .nav-toggle-bars span:last-child{transform:translateY(-3.25px) rotate(-45deg);}

/* Scroll progress */
.scroll-progress{
  position:absolute;
  left:0;
  right:0;
  bottom:0;
  height:2px;
  background:linear-gradient(90deg,var(--cyan-400),var(--amber-400));
  transform:scaleX(0);
  transform-origin:0 50%;
  transition:transform .12s linear;
  pointer-events:none;
}

@media (max-width:1080px){
  .brand-sub{display:none;}
  .nav-link{padding:0 8px;font-size:.86rem;}
}
@media (max-width:900px){
  .site-header{background:rgba(6,17,31,.94);box-shadow:0 1px 0 var(--line);}
  .site-header[data-scrolled="true"]{background:rgba(6,17,31,.98);}
  .header-inner{grid-template-columns:1fr auto;}
  .header-tools{grid-column:2;}
  .index-link{display:none;}
  .nav-toggle{display:inline-flex;}
  .site-nav{
    position:fixed;
    top:0;
    right:0;
    bottom:0;
    width:min(86vw,360px);
    display:flex;
    flex-direction:column;
    align-items:stretch;
    justify-content:flex-start;
    gap:6px;
    padding:calc(var(--header-h) + 20px) 22px 36px;
    background:var(--surface);
    border-left:1px solid var(--line);
    box-shadow:-32px 0 64px -42px #000;
    overflow-y:auto;
    z-index:70;
    transform:translateX(101%);
    visibility:hidden;
    transition:transform .3s var(--ease),visibility .3s var(--ease);
  }
  .site-nav[data-open="true"]{transform:translateX(0);visibility:visible;}
  .nav-list{flex-direction:column;align-items:stretch;gap:0;width:100%;}
  .nav-item{border-bottom:1px solid var(--line-soft);}
  .nav-item:first-child{border-top:1px solid var(--line-soft);}
  .nav-link{width:100%;min-height:48px;padding:12px 4px;font-size:1.02rem;}
  .nav-link::after{display:none;}
  .nav-note{
    display:block;
    margin-top:22px;
    font-family:var(--font-mono);
    font-size:.68rem;
    letter-spacing:.12em;
    color:var(--fog-300);
  }
  html.nav-open{overflow:hidden;}
}
@media (max-width:560px){
  .status-text{display:none;}
  .status-pill{padding:0 11px;}
  .brand-name{font-size:.95rem;}
}

/* ---------- Site footer ---------- */
.site-footer{
  background:var(--ink-950);
  border-top:1px solid var(--line);
  color:var(--text-dim);
  padding-top:clamp(48px,6vw,88px);
}
.footer-inner{
  display:grid;
  grid-template-columns:minmax(0,1fr) minmax(0,1.5fr);
  gap:clamp(32px,5vw,72px);
  padding-bottom:clamp(36px,5vw,64px);
}
.footer-brand{max-width:34ch;}
.footer-brand-name{
  font-size:clamp(22px,2.6vw,30px);
  font-weight:900;
  line-height:1.1;
  letter-spacing:-.02em;
  color:var(--paper-050);
}
.footer-sign{
  margin-top:14px;
  font-size:.95rem;
  line-height:1.7;
  color:var(--fog-300);
}
.footer-meta{
  margin-top:18px;
  font-size:.64rem;
  letter-spacing:.14em;
  color:rgba(169,184,204,.7);
}
.footer-groups{
  display:grid;
  grid-template-columns:repeat(3,minmax(0,1fr));
  gap:clamp(24px,3vw,40px);
  align-items:start;
}
.footer-group{min-width:0;}
.footer-group-title{
  font-family:var(--font-mono);
  font-size:.68rem;
  font-weight:500;
  letter-spacing:.16em;
  text-transform:uppercase;
  color:var(--cyan-400);
  margin-bottom:16px;
}
.footer-links{display:grid;gap:9px;}
.footer-links a{
  display:inline-block;
  padding-block:3px;
  font-size:.94rem;
  color:var(--fog-300);
  border-bottom:1px solid transparent;
  transition:color .18s var(--ease),border-color .18s var(--ease);
}
.footer-links a:hover{color:var(--paper-050);border-color:var(--cyan-600);}
.footer-group--contact{
  display:flex;
  flex-direction:column;
  align-items:flex-start;
  gap:10px;
}
.footer-contact{
  font-size:.86rem;
  line-height:1.7;
  color:var(--fog-300);
}
.copy-btn{
  display:inline-flex;
  align-items:center;
  gap:.7em;
  max-width:100%;
  min-height:40px;
  padding:.42em .78em;
  border-radius:var(--radius-s);
  border:1px solid var(--line);
  background:rgba(12,27,46,.7);
  color:var(--paper-050);
  font-family:var(--font-mono);
  font-size:.76rem;
  letter-spacing:.04em;
  transition:border-color .18s var(--ease),background-color .18s var(--ease);
}
.copy-btn:hover{border-color:rgba(53,230,212,.55);background:rgba(53,230,212,.08);}
.copy-btn.is-copied{border-color:var(--cyan-600);}
.copy-value{overflow-wrap:anywhere;text-align:left;}
.copy-hint{
  flex:none;
  font-size:.64rem;
  letter-spacing:.12em;
  text-transform:uppercase;
  color:var(--cyan-400);
}
.copy-btn.is-copied .copy-hint{color:var(--amber-400);}
.footer-base{
  border-top:1px solid var(--line);
  padding-block:clamp(18px,2.4vw,26px);
}
.footer-base-inner{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  justify-content:space-between;
  gap:10px 24px;
}
.footer-legal{
  font-family:var(--font-mono);
  font-size:.66rem;
  letter-spacing:.1em;
  color:rgba(169,184,204,.78);
}
@media (max-width:820px){
  .footer-inner{grid-template-columns:1fr;}
  .footer-brand{max-width:none;}
}
@media (max-width:600px){
  .footer-groups{grid-template-columns:1fr 1fr;}
  .footer-group--contact{grid-column:1 / -1;}
}

/* ---------- Motion & accessibility ---------- */
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto;}
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
  }
  .reveal{opacity:1;transform:none;}
  .scroll-progress{transition:none;}
}