/* ============================================================
   CHINA KEY — Unlocking the Future of Chinese Tech
   Design system: "Engineering blueprint × seal of China Key"
   ============================================================ */

/* ---- Fonts ---- */
@import url('https://api.fontshare.com/v2/css?f[]=clash-display@500,600,700&f[]=satoshi@400,500,700&display=swap');
@import url('https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@400;500;700&family=Noto+Sans+SC:wght@400;500;700&display=swap');

/* ---- Tokens ---- */
:root{
  --ink:        #0B0D11;
  --ink-2:      #0F121A;
  --ink-3:      #141823;
  --ink-4:      #1B2030;
  --line:       rgba(255,255,255,.08);
  --line-2:     rgba(255,255,255,.16);

  --cinnabar:   #E8463A;   /* signature seal-red */
  --cinnabar-2: #FF6356;
  --cinnabar-d: #C32A20;
  --jade:       #2BD8A6;   /* electric jade — the future */
  --jade-d:     #12A37C;

  --bone:       #F4F0E7;   /* rice-paper light */
  --fg:         #EDEFF3;
  --muted:      #99A1B0;
  --faint:      #626B7C;

  --display: 'Clash Display','Satoshi',system-ui,sans-serif;
  --body:    'Satoshi',system-ui,-apple-system,'Segoe UI',sans-serif;
  --mono:    'JetBrains Mono',ui-monospace,monospace;
  --sc:      'Noto Sans SC',var(--body);

  --wrap: 1200px;
  --r:    14px;
  --r-lg: 22px;
  --ease: cubic-bezier(.22,1,.36,1);
}

/* ---- Reset ---- */
*,*::before,*::after{box-sizing:border-box}
*{margin:0;padding:0}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}
  *,*::before,*::after{animation-duration:.001ms!important;animation-iteration-count:1!important;transition-duration:.001ms!important}}
body{
  font-family:var(--body);
  background:var(--ink);
  color:var(--fg);
  line-height:1.62;
  font-size:17px;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
  overflow-x:hidden;
}
img,svg{display:block;max-width:100%}
a{color:inherit;text-decoration:none}
ul{list-style:none}
button{font:inherit;cursor:pointer;border:none;background:none;color:inherit}
::selection{background:var(--cinnabar);color:#fff}

/* ---- Blueprint backdrop (signature texture) ---- */
body::before{
  content:"";
  position:fixed;inset:0;z-index:-2;
  background:
    linear-gradient(rgba(255,255,255,.022) 1px,transparent 1px) 0 0/64px 64px,
    linear-gradient(90deg,rgba(255,255,255,.022) 1px,transparent 1px) 0 0/64px 64px,
    radial-gradient(900px 600px at 78% -8%,rgba(232,70,58,.14),transparent 60%),
    radial-gradient(800px 700px at 10% 8%,rgba(43,216,166,.10),transparent 55%),
    var(--ink);
  pointer-events:none;
}
body::after{
  content:"";position:fixed;inset:0;z-index:-1;pointer-events:none;
  background:radial-gradient(120% 80% at 50% 0%,transparent 55%,rgba(0,0,0,.55) 100%);
}

/* ---- Layout helpers ---- */
.wrap{max-width:var(--wrap);margin-inline:auto;padding-inline:24px}
.section{padding:96px 0;position:relative}
.section--tight{padding:64px 0}
.divider{height:1px;background:var(--line);max-width:var(--wrap);margin-inline:auto}

/* Schematic eyebrow label — the recurring blueprint callout */
.eyebrow{
  display:inline-flex;align-items:center;gap:10px;
  font-family:var(--mono);font-size:12px;letter-spacing:.22em;
  text-transform:uppercase;color:var(--jade);margin-bottom:22px;
}
.eyebrow::before{content:"";width:26px;height:1px;background:var(--jade);opacity:.7}
.eyebrow .sc{font-family:var(--sc);color:var(--muted);letter-spacing:.05em;font-size:13px}

/* Type scale */
h1,h2,h3,h4{font-family:var(--display);font-weight:600;line-height:1.04;letter-spacing:-.02em}
.h-display{font-size:clamp(2.6rem,6.4vw,5.2rem);font-weight:600;line-height:.98;letter-spacing:-.03em}
h2.title{font-size:clamp(2rem,4vw,3.2rem);letter-spacing:-.025em}
h3{font-size:1.5rem;letter-spacing:-.02em}
.lead{font-size:clamp(1.05rem,1.6vw,1.32rem);color:var(--muted);max-width:62ch;line-height:1.6}
.kicker{font-family:var(--mono);font-size:12.5px;letter-spacing:.18em;text-transform:uppercase;color:var(--faint)}
.strike{position:relative;color:var(--faint);text-decoration:none}
.strike::after{content:"";position:absolute;left:-2%;right:-2%;top:54%;height:.09em;background:var(--cinnabar);transform:rotate(-3deg);border-radius:2px}
.accent-jade{color:var(--jade)}
.accent-red{color:var(--cinnabar-2)}

/* ---- Buttons ---- */
.btn{
  display:inline-flex;align-items:center;gap:10px;
  padding:14px 24px;border-radius:999px;font-weight:600;font-size:15px;
  transition:transform .25s var(--ease),background .25s,border-color .25s,color .25s;
  border:1px solid transparent;white-space:nowrap;
}
.btn:hover{transform:translateY(-2px)}
.btn:focus-visible{outline:2px solid var(--jade);outline-offset:3px}
.btn--primary{background:var(--cinnabar);color:#fff;box-shadow:0 10px 30px -10px rgba(232,70,58,.6)}
.btn--primary:hover{background:var(--cinnabar-2)}
.btn--ghost{border-color:var(--line-2);color:var(--fg)}
.btn--ghost:hover{border-color:var(--jade);color:var(--jade)}
.btn .arr{transition:transform .25s var(--ease)}
.btn:hover .arr{transform:translateX(4px)}

/* ---- Header / Nav ---- */
.site-header{
  position:sticky;top:0;z-index:60;
  backdrop-filter:saturate(140%) blur(14px);
  background:rgba(11,13,17,.66);
  border-bottom:1px solid var(--line);
}
.nav{display:flex;align-items:center;justify-content:space-between;height:74px;gap:24px}
.brand{display:flex;align-items:center;gap:12px;font-family:var(--display);font-weight:600;font-size:20px;letter-spacing:-.01em}
.brand img{width:34px;height:34px;border-radius:9px}
.brand .zh{font-family:var(--sc);color:var(--cinnabar-2);font-weight:700}
.nav-links{display:flex;align-items:center;gap:6px}
.nav-links a{
  padding:9px 14px;border-radius:9px;font-size:14.5px;color:var(--muted);
  font-weight:500;transition:color .2s,background .2s;
}
.nav-links a:hover,.nav-links a[aria-current="page"]{color:var(--fg);background:rgba(255,255,255,.05)}
.nav-cta{display:flex;align-items:center;gap:10px}
.nav-toggle{display:none;width:44px;height:44px;border-radius:10px;border:1px solid var(--line-2);align-items:center;justify-content:center}
.nav-toggle span{position:relative;width:18px;height:2px;background:var(--fg);border-radius:2px;transition:.3s}
.nav-toggle span::before,.nav-toggle span::after{content:"";position:absolute;left:0;width:18px;height:2px;background:var(--fg);border-radius:2px;transition:.3s}
.nav-toggle span::before{top:-6px}.nav-toggle span::after{top:6px}
body.nav-open .nav-toggle span{background:transparent}
body.nav-open .nav-toggle span::before{top:0;transform:rotate(45deg)}
body.nav-open .nav-toggle span::after{top:0;transform:rotate(-45deg)}

/* ---- Hero ---- */
.hero{position:relative;padding:120px 0 90px;overflow:hidden}
.hero .coord{position:absolute;font-family:var(--mono);font-size:11px;color:var(--faint);letter-spacing:.1em}
.hero .coord.tl{top:26px;left:24px}
.hero .coord.tr{top:26px;right:24px;text-align:right}
.hero .coord.br{bottom:26px;right:24px;text-align:right}
.hero-grid{display:grid;grid-template-columns:1.15fr .85fr;gap:56px;align-items:center}
.hero h1{max-width:13ch}
.hero .lead{margin-top:26px}
.hero-cta{display:flex;gap:14px;flex-wrap:wrap;margin-top:38px}
.hero-stats{display:flex;gap:34px;flex-wrap:wrap;margin-top:46px;padding-top:30px;border-top:1px solid var(--line)}
.hero-stats .stat .n{font-family:var(--display);font-size:2.1rem;font-weight:600;letter-spacing:-.02em}
.hero-stats .stat .n .accent-jade{font-family:var(--display)}
.hero-stats .stat .l{font-family:var(--mono);font-size:11.5px;letter-spacing:.08em;color:var(--faint);text-transform:uppercase;margin-top:4px}

/* Hero visual — schematic key */
.hero-visual{position:relative;aspect-ratio:1/1;display:grid;place-items:center}
.hero-visual .ring{position:absolute;inset:0;border:1px solid var(--line);border-radius:50%}
.hero-visual .ring.r2{inset:10%}
.hero-visual .ring.r3{inset:22%;border-style:dashed;border-color:rgba(43,216,166,.25)}
.hero-visual .spin{position:absolute;inset:6%;animation:spin 60s linear infinite}
.hero-visual .spin.rev{inset:24%;animation:spin 44s linear infinite reverse;border-color:rgba(232,70,58,.3)}
@keyframes spin{to{transform:rotate(360deg)}}
.hero-seal{width:46%;filter:drop-shadow(0 24px 60px rgba(232,70,58,.4))}

/* Floating sector chips on hero visual */
.orbit-chip{position:absolute;font-family:var(--mono);font-size:11px;letter-spacing:.05em;
  padding:7px 12px;border:1px solid var(--line-2);border-radius:999px;background:rgba(15,18,26,.85);
  display:flex;gap:7px;align-items:center;color:var(--muted);backdrop-filter:blur(6px)}
.orbit-chip .sc{font-family:var(--sc);color:var(--jade)}
.orbit-chip.c1{top:6%;left:50%;transform:translateX(-50%)}
.orbit-chip.c2{top:46%;right:-6%}
.orbit-chip.c3{bottom:6%;left:50%;transform:translateX(-50%)}
.orbit-chip.c4{top:46%;left:-6%}

/* ---- Generic grids ---- */
.grid{display:grid;gap:22px}
.g-2{grid-template-columns:repeat(2,1fr)}
.g-3{grid-template-columns:repeat(3,1fr)}
.g-4{grid-template-columns:repeat(4,1fr)}

/* ---- Section heading block ---- */
.shead{max-width:64ch;margin-bottom:48px}
.shead.center{margin-inline:auto;text-align:center}
.shead p{color:var(--muted);margin-top:16px;font-size:1.08rem}

/* ---- Sector cards (home) ---- */
.sector{
  position:relative;display:block;padding:30px;border-radius:var(--r-lg);
  background:linear-gradient(160deg,var(--ink-3),var(--ink-2));
  border:1px solid var(--line);overflow:hidden;
  transition:transform .4s var(--ease),border-color .4s,box-shadow .4s;
  min-height:280px;
}
.sector:hover{transform:translateY(-6px);border-color:var(--line-2);box-shadow:0 30px 60px -30px rgba(0,0,0,.7)}
.sector .idx{font-family:var(--mono);font-size:12px;color:var(--faint);letter-spacing:.1em}
.sector .glyph{width:54px;height:54px;margin:18px 0;color:var(--jade)}
.sector h3{font-size:1.55rem;display:flex;align-items:baseline;gap:12px}
.sector h3 .sc{font-family:var(--sc);font-size:1.05rem;color:var(--cinnabar-2);font-weight:500}
.sector p{color:var(--muted);font-size:.97rem;margin-top:10px;max-width:36ch}
.sector .go{margin-top:20px;display:inline-flex;gap:8px;align-items:center;font-family:var(--mono);font-size:12.5px;letter-spacing:.06em;color:var(--jade);text-transform:uppercase}
.sector .go .arr{transition:transform .25s var(--ease)}
.sector:hover .go .arr{transform:translateX(5px)}
.sector::after{content:"";position:absolute;right:-30px;bottom:-30px;width:160px;height:160px;border-radius:50%;
  background:radial-gradient(circle,rgba(232,70,58,.16),transparent 70%);opacity:0;transition:opacity .4s}
.sector:hover::after{opacity:1}

/* ---- Panels / feature cards ---- */
.panel{background:linear-gradient(160deg,var(--ink-3),var(--ink-2));border:1px solid var(--line);border-radius:var(--r-lg);padding:30px}
.panel h3{font-size:1.25rem;margin-bottom:10px}
.panel p{color:var(--muted);font-size:.98rem}
.panel .ic{width:44px;height:44px;color:var(--jade);margin-bottom:18px}

/* ---- Stat band ---- */
.statband{display:grid;grid-template-columns:repeat(4,1fr);gap:1px;background:var(--line);border:1px solid var(--line);border-radius:var(--r-lg);overflow:hidden}
.statband .cell{background:var(--ink-2);padding:34px 26px}
.statband .n{font-family:var(--display);font-size:2.6rem;font-weight:600;letter-spacing:-.03em;line-height:1}
.statband .l{color:var(--muted);font-size:.92rem;margin-top:10px;line-height:1.4}
.statband .src{font-family:var(--mono);font-size:10.5px;color:var(--faint);margin-top:8px;letter-spacing:.04em}

/* ---- Article / insight cards ---- */
.posts{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}
.post{display:flex;flex-direction:column;background:var(--ink-2);border:1px solid var(--line);border-radius:var(--r);overflow:hidden;transition:transform .35s var(--ease),border-color .35s}
.post:hover{transform:translateY(-5px);border-color:var(--line-2)}
.post .thumb{aspect-ratio:16/10;position:relative;overflow:hidden}
.post .thumb svg{width:100%;height:100%}
.post .body{padding:22px;display:flex;flex-direction:column;flex:1}
.post .tag{font-family:var(--mono);font-size:11px;letter-spacing:.1em;text-transform:uppercase;color:var(--jade);margin-bottom:12px}
.post h3{font-size:1.18rem;line-height:1.2}
.post p{color:var(--muted);font-size:.93rem;margin-top:10px;flex:1}
.post .meta{margin-top:18px;font-family:var(--mono);font-size:11.5px;color:var(--faint);letter-spacing:.04em;display:flex;justify-content:space-between}

/* ---- Sector hero (subpages) ---- */
.subhero{padding:80px 0 64px;position:relative}
.subhero .zh-watermark{position:absolute;right:-2%;top:-10%;font-family:var(--sc);font-weight:700;font-size:clamp(8rem,22vw,20rem);color:rgba(255,255,255,.025);line-height:1;pointer-events:none;z-index:0}
.subhero .inner{position:relative;z-index:1;max-width:70ch}
.subhero h1{font-size:clamp(2.4rem,5.4vw,4.2rem);margin:8px 0 22px}
.subhero .lead{font-size:clamp(1.05rem,1.5vw,1.28rem)}

/* ---- Breakdown list (numbered, used for real sequences) ---- */
.steps{display:grid;gap:18px;counter-reset:s}
.step{display:grid;grid-template-columns:auto 1fr;gap:22px;align-items:start;padding:24px;border:1px solid var(--line);border-radius:var(--r);background:var(--ink-2)}
.step .num{font-family:var(--mono);font-size:13px;color:var(--cinnabar-2);letter-spacing:.06em;padding-top:3px}
.step h3{font-size:1.18rem;margin-bottom:6px}
.step p{color:var(--muted);font-size:.96rem}

/* ---- Player chips (key companies) ---- */
.players{display:flex;flex-wrap:wrap;gap:12px}
.player{display:flex;align-items:center;gap:10px;padding:11px 16px;border:1px solid var(--line);border-radius:12px;background:var(--ink-2);font-size:14px}
.player .sc{font-family:var(--sc);color:var(--cinnabar-2);font-size:13px}
.player .dot{width:7px;height:7px;border-radius:50%;background:var(--jade)}

/* ---- Reports ---- */
.report{display:grid;grid-template-columns:120px 1fr auto;gap:24px;align-items:center;padding:24px;border:1px solid var(--line);border-radius:var(--r);background:var(--ink-2);transition:border-color .3s,transform .3s var(--ease)}
.report:hover{border-color:var(--line-2);transform:translateY(-3px)}
.report .cover{aspect-ratio:3/4;border-radius:8px;overflow:hidden;border:1px solid var(--line)}
.report h3{font-size:1.22rem}
.report .desc{color:var(--muted);font-size:.95rem;margin-top:8px;max-width:60ch}
.report .tags{margin-top:12px;display:flex;gap:8px;flex-wrap:wrap}
.report .tags span{font-family:var(--mono);font-size:10.5px;letter-spacing:.08em;text-transform:uppercase;color:var(--faint);border:1px solid var(--line);padding:4px 9px;border-radius:999px}

/* ---- FAQ (answer-engine friendly) ---- */
.faq{border-top:1px solid var(--line)}
.faq details{border-bottom:1px solid var(--line)}
.faq summary{list-style:none;cursor:pointer;padding:24px 0;display:flex;justify-content:space-between;gap:24px;align-items:center;font-family:var(--display);font-weight:500;font-size:1.18rem}
.faq summary::-webkit-details-marker{display:none}
.faq summary .pm{flex:none;width:26px;height:26px;border:1px solid var(--line-2);border-radius:50%;position:relative;transition:transform .3s}
.faq summary .pm::before,.faq summary .pm::after{content:"";position:absolute;background:var(--jade);border-radius:2px;top:50%;left:50%;transform:translate(-50%,-50%)}
.faq summary .pm::before{width:11px;height:1.6px}
.faq summary .pm::after{width:1.6px;height:11px;transition:transform .3s}
.faq details[open] summary .pm::after{transform:translate(-50%,-50%) scaleY(0)}
.faq details p{color:var(--muted);padding:0 0 24px;max-width:80ch;font-size:1rem}

/* ---- CTA band ---- */
.ctaband{position:relative;border-radius:var(--r-lg);overflow:hidden;border:1px solid var(--line);
  background:linear-gradient(135deg,#16110F,#0F1218);padding:64px 48px;text-align:center}
.ctaband::before{content:"";position:absolute;inset:0;z-index:0;
  background:radial-gradient(600px 300px at 50% 0,rgba(232,70,58,.22),transparent 60%),
  radial-gradient(500px 300px at 50% 100%,rgba(43,216,166,.16),transparent 60%)}
.ctaband > *{position:relative;z-index:1}
.ctaband h2{font-size:clamp(1.9rem,4vw,3rem)}
.ctaband p{color:var(--muted);max-width:56ch;margin:16px auto 30px;font-size:1.08rem}
.ctaband .row{display:flex;gap:14px;justify-content:center;flex-wrap:wrap}

/* ---- Prose (article/about bodies) ---- */
.prose{max-width:72ch}
.prose p{color:#C9CFDA;margin-bottom:20px;font-size:1.08rem;line-height:1.72}
.prose h2{font-size:1.8rem;margin:44px 0 16px}
.prose h3{font-size:1.32rem;margin:32px 0 12px}
.prose ul{margin:0 0 22px;padding-left:0}
.prose ul li{position:relative;padding-left:26px;margin-bottom:12px;color:#C9CFDA}
.prose ul li::before{content:"";position:absolute;left:2px;top:11px;width:8px;height:8px;background:var(--cinnabar);border-radius:2px;transform:rotate(45deg)}
.prose strong{color:var(--fg)}
.prose blockquote{border-left:2px solid var(--jade);padding:6px 0 6px 24px;margin:28px 0;font-family:var(--display);font-size:1.3rem;color:var(--fg);line-height:1.4}

/* ---- Forms ---- */
.form{display:grid;gap:18px}
.field label{display:block;font-family:var(--mono);font-size:12px;letter-spacing:.08em;text-transform:uppercase;color:var(--muted);margin-bottom:8px}
.field input,.field textarea,.field select{
  width:100%;padding:14px 16px;border-radius:12px;background:var(--ink-2);
  border:1px solid var(--line-2);color:var(--fg);font:inherit;font-size:15px;transition:border-color .25s}
.field input:focus,.field textarea:focus,.field select:focus{outline:none;border-color:var(--jade)}
.field textarea{min-height:140px;resize:vertical}

/* ---- Footer ---- */
.site-footer{border-top:1px solid var(--line);padding:64px 0 40px;margin-top:40px;background:var(--ink-2)}
.foot-grid{display:grid;grid-template-columns:1.6fr 1fr 1fr 1fr;gap:40px}
.foot-brand .brand{margin-bottom:16px}
.foot-brand p{color:var(--muted);font-size:.95rem;max-width:38ch}
.foot-col h4{font-family:var(--mono);font-size:11.5px;letter-spacing:.14em;text-transform:uppercase;color:var(--faint);margin-bottom:16px;font-weight:500}
.foot-col a{display:block;color:var(--muted);font-size:.95rem;padding:5px 0;transition:color .2s}
.foot-col a:hover{color:var(--jade)}
.foot-bottom{display:flex;justify-content:space-between;align-items:center;gap:20px;flex-wrap:wrap;
  margin-top:48px;padding-top:28px;border-top:1px solid var(--line);font-family:var(--mono);font-size:12px;color:var(--faint);letter-spacing:.04em}

/* ---- Breadcrumb ---- */
.crumbs{font-family:var(--mono);font-size:12px;letter-spacing:.06em;color:var(--faint);padding-top:28px}
.crumbs a:hover{color:var(--jade)}
.crumbs span{color:var(--muted)}

/* ---- Scroll reveal ---- */
.reveal{opacity:0;transform:translateY(22px);transition:opacity .7s var(--ease),transform .7s var(--ease)}
.reveal.in{opacity:1;transform:none}

/* ---- Responsive ---- */
@media (max-width:980px){
  .hero-grid{grid-template-columns:1fr;gap:40px}
  .hero-visual{max-width:420px;margin-inline:auto;order:-1}
  .g-4{grid-template-columns:repeat(2,1fr)}
  .statband{grid-template-columns:repeat(2,1fr)}
  .posts{grid-template-columns:repeat(2,1fr)}
  .foot-grid{grid-template-columns:1fr 1fr;gap:32px}
}
@media (max-width:760px){
  .nav-links,.nav-cta .btn{display:none}
  .nav-toggle{display:flex}
  .nav-links{
    position:fixed;inset:74px 0 auto 0;flex-direction:column;align-items:stretch;gap:0;
    background:rgba(11,13,17,.98);backdrop-filter:blur(16px);border-bottom:1px solid var(--line);
    padding:14px 24px 24px;transform:translateY(-130%);transition:transform .4s var(--ease);z-index:55}
  body.nav-open .nav-links{transform:none;display:flex}
  .nav-links a{padding:14px 8px;font-size:16px;border-radius:8px}
  .section{padding:68px 0}
  .g-2,.g-3{grid-template-columns:1fr}
  .posts{grid-template-columns:1fr}
  .report{grid-template-columns:80px 1fr;gap:18px}
  .report .btn{grid-column:1/-1}
  .step{grid-template-columns:1fr}
  .ctaband{padding:44px 24px}
  .foot-grid{grid-template-columns:1fr 1fr}
  .hero-stats{gap:24px}
}
@media (max-width:440px){
  .statband{grid-template-columns:1fr}
  .foot-grid{grid-template-columns:1fr}
}