/* =========================================================
   时间折叠 · TimeFold — premium glass build
   Dark cosmic backdrop + Apple-grade frosted glass
   ========================================================= */

*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{-webkit-text-size-adjust:100%}
img{display:block;max-width:100%}
a{color:inherit;text-decoration:none}

:root{
  /* ink */
  --white:#FFFFFF;
  --text:#F4F2FB;
  --text-dim:#B9B4D4;
  --text-faint:#7E799B;

  /* brand cosmos */
  --violet:#7C6BFF;
  --indigo:#4C82FF;
  --rose:#F39AD0;
  --mint:#79E6D6;
  --bg:#07060F;

  --grad:linear-gradient(110deg,#9C8BFF 0%,#6E8BFF 42%,#F4A6D8 100%);

  /* glass tokens */
  --glass-bg:linear-gradient(155deg,rgba(255,255,255,.13),rgba(255,255,255,.04));
  --glass-border:rgba(255,255,255,.16);
  --glass-blur:blur(34px) saturate(165%);
  --glass-shadow:0 24px 70px -28px rgba(0,0,0,.75);
  --glass-inset:inset 0 1px 0 rgba(255,255,255,.22),inset 0 -1px 0 rgba(255,255,255,.04);

  --font-display:"Fraunces",Georgia,serif;
  --font-zh:"PingFang SC","Hiragino Sans GB","Source Han Sans SC","Microsoft YaHei",system-ui,sans-serif;
  --font-mono:"Space Grotesk",ui-monospace,"SF Mono",Menlo,monospace;

  --maxw:1180px;
}

html{
  -webkit-font-smoothing:antialiased;
  -moz-osx-font-smoothing:grayscale;
  scroll-behavior:smooth;
}

body{
  font-family:var(--font-zh);
  color:var(--text);
  background:var(--bg);
  line-height:1.6;
  min-height:100vh;
  overflow-x:hidden;
  position:relative;
}

::selection{background:rgba(124,107,255,.4);color:#fff}
:focus-visible{outline:1.5px solid var(--violet);outline-offset:4px;border-radius:6px}

/* =========================================================
   cosmic backdrop
   ========================================================= */
.aurora{
  position:fixed;inset:-20vmax;z-index:-3;
  filter:blur(72px);
  pointer-events:none;
  will-change:transform;
}
.blob{
  position:absolute;border-radius:50%;opacity:.7;
  mix-blend-mode:screen;
}
.blob--violet{width:52vmax;height:52vmax;left:-6vmax;top:-8vmax;
  background:radial-gradient(circle at 50% 50%,var(--violet),transparent 62%);
  animation:drift1 22s ease-in-out infinite;}
.blob--indigo{width:46vmax;height:46vmax;right:-6vmax;top:4vmax;
  background:radial-gradient(circle at 50% 50%,var(--indigo),transparent 62%);
  animation:drift2 27s ease-in-out infinite;}
.blob--rose{width:40vmax;height:40vmax;left:18vmax;bottom:-14vmax;
  background:radial-gradient(circle at 50% 50%,var(--rose),transparent 64%);
  animation:drift3 31s ease-in-out infinite;}
.blob--mint{width:26vmax;height:26vmax;right:14vmax;bottom:-6vmax;
  background:radial-gradient(circle at 50% 50%,var(--mint),transparent 66%);
  opacity:.32;
  animation:drift2 35s ease-in-out infinite reverse;}

@keyframes drift1{50%{transform:translate(6vmax,5vmax) scale(1.12)}}
@keyframes drift2{50%{transform:translate(-7vmax,4vmax) scale(1.08)}}
@keyframes drift3{50%{transform:translate(4vmax,-6vmax) scale(1.15)}}

/* vignette so glass edges read */
body::before{
  content:"";position:fixed;inset:0;z-index:-2;pointer-events:none;
  background:radial-gradient(120% 80% at 50% 0%,transparent 40%,rgba(5,4,12,.55) 100%),
             linear-gradient(180deg,rgba(7,6,15,.2),rgba(7,6,15,.7));
}
.grain{
  position:fixed;inset:0;z-index:-1;pointer-events:none;opacity:.05;
  background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

.cursor-glow{
  position:fixed;top:0;left:0;width:520px;height:520px;z-index:-1;
  margin:-260px 0 0 -260px;border-radius:50%;pointer-events:none;
  background:radial-gradient(circle,rgba(160,140,255,.16),transparent 60%);
  opacity:0;transition:opacity .4s;will-change:transform;
}

/* =========================================================
   glass primitive
   ========================================================= */
.glass{
  position:relative;
  background:var(--glass-bg);
  border:1px solid var(--glass-border);
  -webkit-backdrop-filter:var(--glass-blur);
  backdrop-filter:var(--glass-blur);
  box-shadow:var(--glass-shadow),var(--glass-inset);
}

/* =========================================================
   header
   ========================================================= */
.nav{
  position:fixed;top:clamp(12px,2vw,22px);left:50%;transform:translateX(-50%);
  z-index:50;width:min(calc(100% - 28px),var(--maxw));
  display:flex;align-items:center;justify-content:space-between;
  padding:11px 14px 11px 18px;border-radius:18px;
}
.nav__brand{display:inline-flex;align-items:center;gap:11px;
  font-size:15px;font-weight:600;letter-spacing:.04em;color:var(--text)}
.nav__brand img{height:28px;width:auto;filter:drop-shadow(0 2px 8px rgba(124,107,255,.5))}
.nav__pill{
  display:inline-flex;align-items:center;gap:8px;
  font-family:var(--font-mono);font-size:12.5px;letter-spacing:.02em;color:var(--text-dim);
  padding:8px 15px;border-radius:999px;
  background:rgba(255,255,255,.06);border:1px solid rgba(255,255,255,.12);
  transition:color .25s,border-color .25s,background .25s;
}
.nav__pill:hover{color:#fff;border-color:rgba(160,140,255,.6);background:rgba(124,107,255,.16)}
.nav__dot{width:7px;height:7px;border-radius:50%;background:var(--mint);
  box-shadow:0 0 10px var(--mint);animation:pulse 2.4s ease-in-out infinite}
@keyframes pulse{50%{opacity:.4;transform:scale(.8)}}

/* =========================================================
   hero
   ========================================================= */
.hero{
  max-width:var(--maxw);margin:0 auto;
  min-height:100svh;
  display:grid;
  grid-template-columns:1fr;
  align-content:start;
  gap:clamp(28px,3.6vh,42px);
  padding:clamp(100px,13vh,132px) clamp(20px,5vw,40px) clamp(48px,7vh,72px);
}
.hero__visual{display:flex;justify-content:flex-start}
.hero__intro,.hero__visual,.meta{min-width:0}

@media(min-width:920px){
  .hero{
    grid-template-columns:1.24fr 0.76fr;
    grid-template-areas:"intro visual" "meta visual";
    column-gap:clamp(36px,3.6vw,64px);
    row-gap:clamp(26px,4vh,40px);
    align-content:center;
    align-items:center;
  }
  .hero__intro{grid-area:intro;align-self:end}
  .hero__visual{grid-area:visual;align-self:center;justify-content:center}
  .meta{grid-area:meta;align-self:start}
}

/* eyebrow */
.eyebrow{
  display:inline-flex;align-items:center;gap:12px;
  font-family:var(--font-mono);font-size:12px;font-weight:500;
  letter-spacing:.3em;text-transform:uppercase;color:var(--text-faint);
  margin-bottom:clamp(20px,2.6vh,28px);
  opacity:0;animation:rise .8s cubic-bezier(.2,.8,.25,1) .15s forwards;
}
.eyebrow__sep{color:rgba(255,255,255,.22)}
.clock{color:var(--text-dim);letter-spacing:.18em;font-variant-numeric:tabular-nums}

/* headline */
.headline{
  font-family:var(--font-zh);
  font-weight:300;
  font-size:clamp(38px,4.7vw,66px);
  line-height:1.26;
  letter-spacing:.005em;
  color:var(--text);
  text-shadow:0 2px 40px rgba(0,0,0,.3);
}
.headline__line{
  display:block;
  white-space:nowrap;          /* never break a line internally */
  opacity:0;
  animation:rise 1s cubic-bezier(.2,.8,.25,1) forwards;
}
.headline__line:nth-child(1){animation-delay:.26s}
.headline__line:nth-child(2){animation-delay:.42s}

/* the fold word */
.fold{
  display:inline-block;
  perspective:620px;
  cursor:default;
}
.fold__char{
  display:inline-block;
  font-weight:400;
  background:var(--grad);
  background-size:220% 100%;
  -webkit-background-clip:text;background-clip:text;
  -webkit-text-fill-color:transparent;color:transparent;
  animation:shimmer 7s ease-in-out infinite;
  transform-origin:50% 100%;
  transition:transform .55s cubic-bezier(.2,.8,.25,1);
  will-change:transform;
}
.fold__char:nth-child(2){animation-delay:-.6s}
.fold.is-folded .fold__char:nth-child(1){transform:rotateX(78deg) translateY(-2px)}
.fold.is-folded .fold__char:nth-child(2){transform:rotateX(-78deg) translateY(2px)}
@keyframes shimmer{50%{background-position:100% 0}}

@keyframes rise{
  from{opacity:0;transform:translateY(30px);filter:blur(8px)}
  to{opacity:1;transform:translateY(0);filter:blur(0)}
}

/* tagline */
.tagline{
  margin-top:clamp(24px,3.4vh,38px);
  opacity:0;animation:rise .9s cubic-bezier(.2,.8,.25,1) .82s forwards;
}
.tagline__zh{
  font-size:clamp(16px,2vw,21px);color:var(--text-dim);
  letter-spacing:.04em;font-weight:300;
}
.tagline__en{
  margin-top:9px;
  font-family:var(--font-mono);font-size:11.5px;font-weight:400;
  letter-spacing:.28em;color:var(--text-faint);
}

/* logo card */
.logo-card{
  width:100%;max-width:480px;
  border-radius:24px;
  padding:clamp(26px,3.2vw,42px) clamp(28px,4vw,48px);
  display:flex;align-items:center;justify-content:center;
  overflow:hidden;
  transform-style:preserve-3d;
  transition:transform .35s cubic-bezier(.2,.8,.25,1),box-shadow .35s;
  opacity:0;animation:rise 1s cubic-bezier(.2,.8,.25,1) 1s forwards;
}
.logo-card img{
  width:100%;max-width:340px;height:auto;
  filter:drop-shadow(0 10px 34px rgba(124,107,255,.45));
  transform:translateZ(38px);
}
.logo-card__sheen{
  position:absolute;inset:0;border-radius:inherit;pointer-events:none;
  background:radial-gradient(420px circle at var(--mx,30%) var(--my,0%),
            rgba(255,255,255,.28),transparent 45%);
  opacity:.6;transition:opacity .4s;mix-blend-mode:soft-light;
}

/* meta row */
.meta{
  display:flex;flex-wrap:wrap;gap:10px;
  opacity:0;animation:rise .9s cubic-bezier(.2,.8,.25,1) 1.15s forwards;
}
.meta__item{
  display:inline-flex;align-items:baseline;gap:9px;
  padding:10px 15px;border-radius:12px;
  font-size:13.5px;color:var(--text);
  transition:transform .3s,border-color .3s,background .3s;
}
a.meta__item:hover{transform:translateY(-3px);border-color:rgba(160,140,255,.55)}
.meta__k{font-family:var(--font-mono);font-size:11px;letter-spacing:.18em;
  text-transform:uppercase;color:var(--text-faint)}
.meta__v{font-weight:500;letter-spacing:.01em}

/* =========================================================
   footer
   ========================================================= */
.footer{
  position:relative;z-index:1;
  max-width:var(--maxw);margin:0 auto;
  padding:26px clamp(20px,5vw,40px) 40px;
  display:flex;flex-wrap:wrap;align-items:center;gap:10px 28px;
  font-family:var(--font-mono);font-size:11.5px;letter-spacing:.04em;
  color:var(--text-faint);
  border-top:1px solid rgba(255,255,255,.08);
}
.footer__en{color:rgba(255,255,255,.28)}
.footer a{transition:color .25s}
.footer a:hover{color:var(--text-dim)}

/* =========================================================
   responsive
   ========================================================= */
@media(max-width:680px){
  .nav{min-width:0}
  .nav__brand{min-width:0;flex:0 1 auto}
  .nav__brand span{font-size:14px}
  .nav__pill{min-width:0;max-width:48%;overflow:hidden;white-space:nowrap;padding-inline:12px}
  .headline{font-size:clamp(33px,9vw,50px);line-height:1.26;letter-spacing:.005em}
  .headline__line{white-space:normal}
  .logo-card{max-width:none;padding:28px 24px}
  .logo-card img{max-width:100%;object-fit:contain}
  .meta{width:100%}
  .meta__item{flex:1 1 100%}
  .footer{flex-direction:column;align-items:flex-start;gap:8px}
}

@media(prefers-reduced-motion:reduce){
  *,*::before,*::after{animation:none!important;transition:none!important}
  .headline__line,.eyebrow,.tagline,.logo-card,.meta{opacity:1!important;filter:none!important;transform:none!important}
}