/* =============================================================
   幻影平台入口 · /assets/site.css
   暗场影厅 + 光学实验场：墨黑幕布、幻影紫投射光晕、
   电光青交互、琥珀金索引数字、暖纸色近读亮区。
   ============================================================= */

/* ---------- 1. Design tokens ---------- */
:root{
  --ink:#07070F;
  --night:#111327;
  --violet:#7B4DFF;
  --violet-deep:#3A1F70;
  --cyan:#39E6FF;
  --amber:#FFB547;
  --paper:#F3E8D6;
  --paper-grey:#C9BFAE;
  --white:#F7F8FF;

  --line:rgba(201,191,174,.16);
  --line-strong:rgba(201,191,174,.34);

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

  --step-1:12px;
  --step-2:14px;
  --step-3:16px;
  --step-4:20px;
  --step-5:28px;
  --step-6:40px;
  --step-7:64px;
  --step-8:96px;

  --maxw:1320px;
  --gutter:64px;
  --radius:2px;
  --ease:cubic-bezier(.22,.61,.36,1);
}

/* ---------- 2. Reset ---------- */
*,*::before,*::after{box-sizing:border-box}
html,body{margin:0;padding:0}
html{
  background-color:var(--ink);
  -webkit-text-size-adjust:100%;
  text-size-adjust:100%;
  scroll-behavior:smooth;
}
body{
  min-height:100vh;
  font-family:var(--font-body);
  font-size:var(--step-3);
  font-weight:400;
  line-height:1.75;
  color:var(--white);
  background:transparent;
  overflow-x:hidden;
  -webkit-font-smoothing:antialiased;
  -moz-osx-font-smoothing:grayscale;
}
body::before{
  content:"";
  position:fixed;
  z-index:-1;
  top:-25vh;
  left:-10vw;
  right:-10vw;
  height:105vh;
  pointer-events:none;
  background:
    radial-gradient(52% 46% at 32% 24%, rgba(123,77,255,.30), rgba(123,77,255,0) 68%),
    radial-gradient(42% 38% at 80% 8%, rgba(57,230,255,.13), rgba(57,230,255,0) 70%),
    radial-gradient(60% 50% at 50% 100%, rgba(58,31,112,.42), rgba(58,31,112,0) 72%);
  animation:beam-drift 26s ease-in-out infinite alternate;
}
@keyframes beam-drift{
  from{transform:translate3d(-1.5%,0,0) scale(1)}
  to{transform:translate3d(2%,2.2%,0) scale(1.05)}
}
img,svg,video{max-width:100%;height:auto;display:block}
button{font:inherit}
::selection{background:var(--violet);color:var(--white)}

/* ---------- 3. Typography ---------- */
h1,h2,h3,h4{
  font-family:var(--font-display);
  font-weight:900;
  line-height:1.15;
  letter-spacing:-.02em;
  color:var(--white);
  margin:0 0 .55em;
}
h1{font-size:clamp(36px,5.5vw,64px)}
h2{font-size:clamp(26px,3.4vw,40px)}
h3{font-size:clamp(20px,2.2vw,28px)}
h4{font-size:var(--step-4);letter-spacing:0}
p{margin:0 0 1em}
p:last-child{margin-bottom:0}
a{color:var(--cyan);text-decoration:none;transition:color .2s var(--ease)}
a:hover{color:var(--white)}
strong{font-weight:600;color:var(--white)}
code,kbd,samp{font-family:var(--font-mono);font-size:.92em;letter-spacing:.04em}
hr{border:0}

/* ---------- 4. Focus & motion ---------- */
:focus-visible{
  outline:2px solid var(--cyan);
  outline-offset:3px;
  border-radius:var(--radius);
}
@media (prefers-reduced-motion: reduce){
  html{scroll-behavior:auto}
  body::before{animation:none}
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
  }
}

/* ---------- 5. Layout utilities ---------- */
.container{
  width:100%;
  max-width:var(--maxw);
  margin:0 auto;
  padding-left:var(--gutter);
  padding-right:var(--gutter);
}
.section{padding:clamp(52px,7vw,96px) 0}
.section--tight{padding:clamp(30px,4vw,52px) 0}
.grid{display:grid;gap:clamp(20px,2.4vw,32px)}
.grid--2{grid-template-columns:repeat(2,minmax(0,1fr))}
.grid--3{grid-template-columns:repeat(3,minmax(0,1fr))}
.grid--rail{grid-template-columns:minmax(0,1.65fr) minmax(0,1fr)}
.eyebrow{
  display:inline-flex;
  align-items:center;
  gap:10px;
  margin:0 0 14px;
  font-family:var(--font-mono);
  font-size:11px;
  font-weight:500;
  letter-spacing:.22em;
  text-transform:uppercase;
  color:var(--cyan);
}
.eyebrow::before{
  content:"";
  width:24px;
  height:1px;
  flex:none;
  background:var(--cyan);
}
.divider{
  height:1px;
  border:0;
  margin:clamp(24px,3vw,40px) 0;
  background:linear-gradient(90deg,transparent,var(--line-strong) 12%,var(--line-strong) 88%,transparent);
}

/* ---------- 6. Buttons & chips ---------- */
.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:10px;
  padding:13px 24px;
  font-family:var(--font-body);
  font-size:var(--step-2);
  font-weight:600;
  line-height:1.2;
  letter-spacing:.02em;
  text-align:center;
  text-decoration:none;
  border:1px solid transparent;
  border-radius:var(--radius);
  cursor:pointer;
  transition:background .22s var(--ease),color .22s var(--ease),
             border-color .22s var(--ease),box-shadow .22s var(--ease),
             transform .22s var(--ease);
}
.btn--primary{
  background:linear-gradient(118deg,var(--violet) 0%,#9B6BFF 52%,var(--violet) 100%);
  color:var(--white);
  border-color:rgba(247,248,255,.18);
  box-shadow:0 12px 34px -18px rgba(123,77,255,.95);
}
.btn--primary:hover{
  color:var(--white);
  box-shadow:0 0 0 4px rgba(123,77,255,.16),0 16px 38px -16px rgba(123,77,255,.95);
  transform:translateY(-1px);
}
.btn--ghost{
  background:transparent;
  color:var(--cyan);
  border-color:rgba(57,230,255,.45);
}
.btn--ghost:hover{
  color:var(--white);
  background:rgba(57,230,255,.10);
  border-color:var(--cyan);
}
.btn--quiet{
  background:transparent;
  color:var(--paper-grey);
  border-color:var(--line-strong);
}
.btn--quiet:hover{
  color:var(--white);
  border-color:var(--paper-grey);
}
.btn--sm{padding:9px 16px;font-size:var(--step-1);letter-spacing:.05em}
.chip{
  display:inline-flex;
  align-items:center;
  gap:8px;
  padding:7px 15px;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.09em;
  color:var(--paper-grey);
  background:rgba(17,19,39,.62);
  border:1px solid var(--line-strong);
  border-radius:999px;
  cursor:pointer;
  transition:color .2s var(--ease),border-color .2s var(--ease),
             background .2s var(--ease),box-shadow .2s var(--ease);
}
.chip:hover{color:var(--white);border-color:var(--paper-grey)}
.chip[aria-pressed="true"],
.chip.is-active{
  color:var(--white);
  border-color:var(--cyan);
  background:rgba(57,230,255,.14);
  box-shadow:inset 0 0 0 1px rgba(57,230,255,.42);
}
.chip__count{
  font-variant-numeric:tabular-nums;
  color:var(--amber);
  letter-spacing:0;
}

/* ---------- 7. Breadcrumb ---------- */
.breadcrumb{
  margin:0 0 clamp(20px,2.6vw,32px);
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.1em;
}
.breadcrumb__list{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:8px;
  margin:0;
  padding:0;
  list-style:none;
}
.breadcrumb__item{
  display:inline-flex;
  align-items:center;
  gap:8px;
  color:var(--paper-grey);
}
.breadcrumb__item + .breadcrumb__item::before{
  content:"/";
  color:var(--line-strong);
}
.breadcrumb__item[aria-current="page"]{color:var(--amber)}
.breadcrumb__link{color:var(--paper-grey);text-decoration:none}
.breadcrumb__link:hover{color:var(--cyan)}

/* ---------- 8. Cards, media, stats ---------- */
.paper-card{
  background:var(--paper);
  color:var(--ink);
  padding:clamp(20px,2.4vw,32px);
  border-radius:var(--radius);
  box-shadow:0 28px 56px -34px rgba(0,0,0,.95);
}
.paper-card h2,
.paper-card h3,
.paper-card h4{color:var(--ink)}
.paper-card a{color:var(--violet-deep)}
.paper-card a:hover{color:var(--ink)}

.media-frame{
  position:relative;
  display:block;
  overflow:hidden;
  aspect-ratio:16 / 9;
  border:1px solid var(--line-strong);
  border-radius:var(--radius);
  background:
    radial-gradient(70% 90% at 24% 12%, rgba(123,77,255,.34), rgba(123,77,255,0) 62%),
    linear-gradient(158deg, rgba(58,31,112,.55), rgba(7,7,15,.96) 72%);
}
.media-frame img{
  width:100%;
  height:100%;
  object-fit:cover;
  display:block;
}
.media-frame::before,
.media-frame::after{
  content:"";
  position:absolute;
  width:16px;
  height:16px;
  border:1px solid var(--cyan);
  opacity:.68;
  pointer-events:none;
}
.media-frame::before{top:10px;left:10px;border-right:0;border-bottom:0}
.media-frame::after{bottom:10px;right:10px;border-left:0;border-top:0}
.media-frame--wide{aspect-ratio:21 / 9}
.media-frame--tall{aspect-ratio:4 / 5}
.media-frame__caption{
  position:absolute;
  left:0;
  right:0;
  bottom:0;
  margin:0;
  padding:12px 16px;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.08em;
  color:var(--paper-grey);
  background:linear-gradient(180deg,rgba(7,7,15,0),rgba(7,7,15,.92));
}

.stat{display:flex;flex-direction:column;gap:6px}
.stat__value{
  font-family:var(--font-mono);
  font-size:clamp(28px,3.4vw,44px);
  font-weight:700;
  line-height:1;
  letter-spacing:-.02em;
  font-variant-numeric:tabular-nums;
  color:var(--amber);
}
.stat__label{
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.14em;
  color:var(--paper-grey);
}

/* ---------- 9. Skip link ---------- */
.skip-link{
  position:absolute;
  left:16px;
  top:-72px;
  z-index:80;
  padding:12px 20px;
  font-family:var(--font-mono);
  font-size:var(--step-1);
  letter-spacing:.1em;
  color:var(--ink);
  background:var(--paper);
  text-decoration:none;
  border-radius:0 0 var(--radius) var(--radius);
  transition:top .2s var(--ease);
}
.skip-link:focus,
.skip-link:focus-visible{
  top:0;
  color:var(--ink);
}

/* ---------- 10. Header ---------- */
.site-header{
  position:sticky;
  top:0;
  z-index:40;
  background:rgba(7,7,15,.88);
  -webkit-backdrop-filter:blur(14px) saturate(130%);
  backdrop-filter:blur(14px) saturate(130%);
  border-bottom:1px solid var(--line);
  transition:background .3s var(--ease),border-color .3s var(--ease);
}
.header-utility{
  max-height:48px;
  overflow:hidden;
  background:rgba(17,19,39,.55);
  border-bottom:1px solid rgba(201,191,174,.10);
  transition:max-height .35s var(--ease),opacity .25s var(--ease);
}
.header-utility__inner{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  justify-content:center;
  gap:4px 26px;
  min-height:36px;
  max-width:var(--maxw);
  margin:0 auto;
  padding:0 var(--gutter);
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.07em;
  color:var(--paper-grey);
}
.utility-item{white-space:nowrap}
.utility-item--key{color:var(--amber)}

.masthead{background:transparent}
.masthead__inner{
  display:grid;
  grid-template-columns:1fr auto 1fr;
  align-items:center;
  gap:16px;
  max-width:var(--maxw);
  margin:0 auto;
  padding:22px var(--gutter) 16px;
  transition:padding .3s var(--ease);
}
.masthead__edition{
  justify-self:start;
  margin:0;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.14em;
  color:var(--paper-grey);
  white-space:nowrap;
}
.masthead__brand{
  justify-self:center;
  display:inline-flex;
  align-items:center;
  gap:12px;
  color:var(--white);
  text-decoration:none;
}
.masthead__brand:hover{color:var(--white)}
.brand-mark{
  width:13px;
  height:13px;
  flex:none;
  transform:rotate(45deg);
  border:1px solid rgba(123,77,255,.85);
  background:radial-gradient(circle at 30% 30%,var(--cyan),var(--violet) 72%);
  box-shadow:0 0 14px rgba(123,77,255,.75);
}
.brand-name{
  font-family:var(--font-display);
  font-weight:900;
  font-size:clamp(18px,2.1vw,26px);
  letter-spacing:.01em;
  line-height:1.1;
  white-space:nowrap;
  transition:font-size .3s var(--ease);
}

.nav-toggle{
  justify-self:end;
  display:none;
  align-items:center;
  gap:10px;
  padding:9px 13px;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.16em;
  color:var(--white);
  background:transparent;
  border:1px solid var(--line-strong);
  border-radius:var(--radius);
  cursor:pointer;
  transition:border-color .2s var(--ease),color .2s var(--ease);
}
.nav-toggle:hover{border-color:var(--cyan);color:var(--cyan)}
.nav-toggle__bars{
  display:inline-flex;
  flex-direction:column;
  justify-content:center;
  gap:4px;
  width:16px;
  height:12px;
}
.nav-toggle__bars span{
  display:block;
  height:1px;
  width:100%;
  background:var(--cyan);
  transition:transform .25s var(--ease);
}
.site-header[data-open] .nav-toggle__bars span:first-child{transform:translateY(2.5px) rotate(45deg)}
.site-header[data-open] .nav-toggle__bars span:last-child{transform:translateY(-2.5px) rotate(-45deg)}

/* ---------- 11. Navigation ---------- */
.site-nav{
  background:rgba(17,19,39,.5);
  border-top:1px solid var(--line);
}
.site-nav__inner{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  justify-content:center;
  gap:6px 10px;
  min-height:56px;
  max-width:var(--maxw);
  margin:0 auto;
  padding:10px var(--gutter);
}
.site-nav__list{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  justify-content:center;
  gap:2px;
  margin:0;
  padding:0;
  list-style:none;
}
.site-nav__item{display:block}
.site-nav__link{
  position:relative;
  display:inline-block;
  padding:9px 15px;
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.1em;
  color:var(--paper-grey);
  text-decoration:none;
  border-radius:var(--radius);
  transition:color .2s var(--ease);
}
.site-nav__link::after{
  content:"";
  position:absolute;
  left:15px;
  right:15px;
  bottom:4px;
  height:1px;
  background:var(--cyan);
  transform:scaleX(0);
  transform-origin:left center;
  transition:transform .26s var(--ease);
}
.site-nav__link:hover,
.site-nav__link:focus-visible{color:var(--white)}
.site-nav__link:hover::after,
.site-nav__link:focus-visible::after{transform:scaleX(1)}
.site-nav__link[aria-current="page"]{color:var(--amber)}
.site-nav__link[aria-current="page"]::after{
  transform:scaleX(1);
  background:var(--amber);
}
.site-nav__action{display:flex;align-items:center}
.site-nav__meta{
  display:none;
  margin:0;
  font-family:var(--font-mono);
  font-size:11px;
  line-height:1.9;
  letter-spacing:.07em;
  color:var(--paper-grey);
}
.site-nav__meta p{margin:0}

.header-progress{
  position:absolute;
  left:0;
  right:0;
  bottom:-1px;
  height:2px;
  pointer-events:none;
}
.header-progress__bar{
  display:block;
  height:100%;
  width:100%;
  transform:scaleX(0);
  transform-origin:left center;
  background:linear-gradient(90deg,var(--violet),var(--cyan) 62%,var(--amber));
}

.site-header[data-scrolled] .header-utility{max-height:0;opacity:0}
.site-header[data-scrolled] .masthead__inner{padding-top:11px;padding-bottom:9px}
.site-header[data-scrolled] .brand-name{font-size:clamp(16px,1.7vw,19px)}

/* ---------- 12. Footer ---------- */
.site-footer{
  position:relative;
  margin-top:clamp(48px,7vw,104px);
  overflow:hidden;
  background:linear-gradient(180deg,rgba(17,19,39,.92) 0%,#06060d 72%);
  border-top:1px solid var(--line);
}
.site-footer__beam{
  position:absolute;
  top:-1px;
  left:50%;
  width:min(760px,86%);
  height:300px;
  transform:translateX(-50%);
  pointer-events:none;
  background:radial-gradient(52% 100% at 50% 0%,rgba(123,77,255,.34),rgba(123,77,255,0) 72%);
}
.site-footer__inner{
  position:relative;
  z-index:1;
  max-width:var(--maxw);
  margin:0 auto;
  padding:clamp(48px,6vw,80px) var(--gutter) 32px;
}
.footer-grid{
  display:grid;
  grid-template-columns:minmax(0,1.6fr) repeat(3,minmax(0,.85fr));
  gap:clamp(30px,4vw,48px);
}
.footer-lead__brand{
  margin:0 0 14px;
  font-family:var(--font-display);
  font-weight:900;
  font-size:clamp(20px,2.4vw,28px);
  line-height:1.3;
  letter-spacing:-.01em;
  color:var(--white);
}
.footer-lead__desc{
  margin:0 0 14px;
  max-width:38ch;
  font-size:var(--step-2);
  line-height:1.85;
  color:var(--paper-grey);
}
.footer-lead__note{
  margin:0;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.14em;
  color:var(--amber);
}
.footer-col__title{
  margin:0 0 16px;
  font-family:var(--font-mono);
  font-size:11px;
  font-weight:500;
  letter-spacing:.2em;
  text-transform:uppercase;
  color:var(--amber);
  line-height:1.4;
}
.footer-col__list{
  display:grid;
  gap:11px;
  margin:0;
  padding:0;
  list-style:none;
}
.footer-col__link{
  font-size:var(--step-2);
  color:var(--paper-grey);
  text-decoration:none;
  transition:color .2s var(--ease);
}
.footer-col__link:hover,
.footer-col__link:focus-visible{color:var(--white)}
.footer-base{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  justify-content:space-between;
  gap:12px 32px;
  margin-top:clamp(36px,4.5vw,60px);
  padding-top:24px;
  border-top:1px solid var(--line);
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.06em;
  color:var(--paper-grey);
}
.footer-base__contact{
  display:flex;
  flex-wrap:wrap;
  gap:6px 22px;
}
.footer-base__legal{
  display:flex;
  flex-wrap:wrap;
  gap:6px 22px;
  align-items:center;
}
.footer-base__legal span{white-space:normal}

/* ---------- 13. Reveal ---------- */
@media (prefers-reduced-motion: no-preference){
  html.js [data-reveal]{
    opacity:0;
    transform:translateY(18px);
    transition:opacity .6s var(--ease),transform .6s var(--ease);
    will-change:opacity,transform;
  }
  html.js [data-reveal].is-visible{
    opacity:1;
    transform:none;
  }
}

/* ---------- 14. Responsive ---------- */
@media (max-width:1100px){
  .masthead__edition{display:none}
  .masthead__inner{grid-template-columns:auto 1fr auto}
  .masthead__brand{justify-self:center;grid-column:2}
}

@media (max-width:1024px){
  :root{--gutter:32px}
  .grid--rail{grid-template-columns:1fr}
}

@media (max-width:960px){
  .nav-toggle{display:inline-flex}
  .masthead__inner{padding-top:16px;padding-bottom:14px}
  .site-nav{
    position:absolute;
    left:0;
    right:0;
    top:100%;
    max-height:0;
    overflow:hidden;
    visibility:hidden;
    background:rgba(9,10,22,.985);
    border-top:1px solid var(--line);
    border-bottom:1px solid var(--line);
    box-shadow:0 30px 70px -34px rgba(0,0,0,.95);
    transition:max-height .35s var(--ease),visibility .35s var(--ease);
  }
  .site-header[data-open] .site-nav{
    max-height:80vh;
    overflow-y:auto;
    visibility:visible;
  }
  .site-nav__inner{
    flex-direction:column;
    align-items:stretch;
    justify-content:flex-start;
    min-height:0;
    padding:18px var(--gutter) 28px;
    gap:0;
  }
  .site-nav__list{
    flex-direction:column;
    align-items:stretch;
    width:100%;
    gap:0;
  }
  .site-nav__link{
    padding:14px 0;
    font-size:13px;
    letter-spacing:.08em;
    border-bottom:1px solid var(--line);
    border-radius:0;
  }
  .site-nav__link::after{display:none}
  .site-nav__link[aria-current="page"]{color:var(--amber)}
  .site-nav__action{margin-top:20px}
  .site-nav__action .btn{width:100%}
  .site-nav__meta{display:block;margin-top:20px}
  .masthead__edition{display:none}
  .site-header[data-scrolled] .site-nav{border-top-color:transparent}
}

@media (max-width:900px){
  .grid--2,.grid--3{grid-template-columns:1fr}
  .footer-grid{grid-template-columns:repeat(2,minmax(0,1fr))}
  .footer-lead{grid-column:1 / -1}
}

@media (max-width:640px){
  :root{--gutter:20px}
  body{font-size:15px}
  .header-utility__inner{font-size:10px;gap:2px 16px;min-height:32px;letter-spacing:.04em}
  .brand-name{font-size:17px}
  .site-nav__action .btn{font-size:12px}
  .footer-grid{grid-template-columns:1fr;gap:30px}
  .footer-base{flex-direction:column;align-items:flex-start}
  .footer-base__legal{flex-direction:column;align-items:flex-start;gap:6px}
  .media-frame--tall{aspect-ratio:3 / 4}
}