/* ==========================================================================
   乐投官网 · 共享样式 /assets/site.css
   1 变量  2 重置  3 中文排版  4 工具类  5 头部  6 页脚
   7 按钮  8 标签与索引  9 图片容器  10 面包屑  11 回到顶部
   12 响应式  13 动效降级
   ========================================================================== */

/* 1 变量 ---------------------------------------------------------------- */
:root{
  --deep:#081826;
  --blueprint:#0F2E4A;
  --cyan:#2EE6D6;
  --mist:#A9F5EF;
  --amber:#F3B64A;
  --paper:#F3EDE1;
  --ink:#111A22;
  --slate:#60788C;
  --fog:#D9E4EE;
  --teal:#0B6B66;

  --bg-page:linear-gradient(168deg,#EFF4F8 0%,#DEE8F0 48%,#D2DEE9 100%);
  --line-light:rgba(96,120,140,.22);
  --line-dark:rgba(46,230,214,.24);

  --font-body:'Noto Sans SC','PingFang SC','Microsoft YaHei',sans-serif;
  --font-mono:'JetBrains Mono','Roboto Mono','SFMono-Regular',monospace;

  --max:1280px;
  --reading:760px;
  --gutter:clamp(1.125rem,4vw,3rem);
  --header-h:76px;
  --radius:18px;
  --radius-sm:10px;
  --ease:200ms ease;
  --shadow-soft:0 26px 64px -46px rgba(8,24,38,.9);
}

/* 2 重置 ---------------------------------------------------------------- */
*,
*::before,
*::after{box-sizing:border-box;}

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

body{
  margin:0;
  min-height:100vh;
  font-family:var(--font-body);
  font-size:clamp(1rem,.35vw + .93rem,1.0625rem);
  line-height:1.75;
  color:var(--ink);
  background:var(--bg-page);
  background-attachment:fixed;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}

h1,h2,h3,h4,h5,p,figure,blockquote,dl,dd{margin:0;}

img,svg,video{display:block;max-width:100%;}

button{font:inherit;color:inherit;}

:focus-visible{
  outline:2px solid var(--cyan);
  outline-offset:3px;
  border-radius:4px;
}

.skip-link{
  position:fixed;
  top:.5rem;
  left:.5rem;
  z-index:200;
  padding:.65rem 1.1rem;
  border-radius:var(--radius-sm);
  background:var(--amber);
  color:#241802;
  font-size:.875rem;
  font-weight:700;
  text-decoration:none;
  transform:translateY(-160%);
  transition:transform var(--ease);
}
.skip-link:focus-visible{transform:translateY(0);}

body.is-nav-open{overflow:hidden;}

/* 3 中文排版 ------------------------------------------------------------ */
.title-hero{
  margin:0;
  font-size:clamp(2.6rem,7vw,6.4rem);
  line-height:1.02;
  font-weight:900;
  letter-spacing:-.03em;
}

.title-section{
  margin:0;
  font-size:clamp(1.6rem,3vw,2.8rem);
  line-height:1.16;
  font-weight:800;
  letter-spacing:-.02em;
}

.title-block{
  margin:0;
  font-size:clamp(1.15rem,1.6vw,1.4rem);
  line-height:1.42;
  font-weight:700;
  letter-spacing:-.01em;
}

.lede{
  max-width:52ch;
  font-size:clamp(1.0625rem,1.3vw,1.25rem);
  line-height:1.72;
  color:var(--slate);
}

.note{
  font-size:.8125rem;
  line-height:1.68;
  color:var(--slate);
}

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

/* 4 工具类 -------------------------------------------------------------- */
.container{
  width:100%;
  max-width:var(--max);
  margin-inline:auto;
  padding-inline:var(--gutter);
}

.reading{
  max-width:var(--reading);
  margin-inline:auto;
}

.section{
  padding-block:clamp(2.75rem,7vw,5.5rem);
}

.section--dark{
  background:
    radial-gradient(120% 90% at 8% 0%,rgba(46,230,214,.12) 0%,rgba(46,230,214,0) 58%),
    linear-gradient(180deg,var(--deep) 0%,var(--blueprint) 100%);
  color:#E9F4FC;
}

.section--paper{
  background:var(--paper);
  color:var(--ink);
  background-image:
    linear-gradient(rgba(17,26,34,.035) 1px,transparent 1px);
  background-size:100% 32px;
}

.section--dark .lede{color:rgba(196,216,232,.86);}
.section--dark .note{color:rgba(160,186,205,.9);}
.section--dark .title-section{color:#F2FAFF;}

.grid{
  display:grid;
  grid-template-columns:repeat(12,minmax(0,1fr));
  gap:clamp(1rem,2.4vw,2rem);
}

.exhibit-label{
  display:inline-flex;
  align-items:center;
  gap:.6rem;
  font-family:var(--font-mono);
  font-size:.75rem;
  letter-spacing:.16em;
  text-transform:uppercase;
  color:var(--teal);
}
.exhibit-label::before{
  content:"";
  width:26px;
  height:1px;
  background:currentColor;
}
.section--dark .exhibit-label{color:var(--cyan);}

/* 5 头部 ---------------------------------------------------------------- */
.site-header{
  position:sticky;
  top:0;
  z-index:90;
  color:var(--mist);
  background:rgba(8,24,38,.72);
  -webkit-backdrop-filter:blur(12px) saturate(120%);
  backdrop-filter:blur(12px) saturate(120%);
  border-bottom:1px solid rgba(169,245,239,.14);
  transition:background var(--ease),border-color var(--ease),box-shadow var(--ease);
}
.site-header[data-scrolled]{
  background:var(--blueprint);
  border-bottom-color:rgba(46,230,214,.36);
  box-shadow:0 18px 40px -34px #000,0 1px 0 rgba(46,230,214,.12) inset;
}

.site-header__inner{
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:clamp(.75rem,2.5vw,2.5rem);
  width:100%;
  max-width:var(--max);
  min-height:var(--header-h);
  margin-inline:auto;
  padding-inline:var(--gutter);
}

.brand{
  display:flex;
  align-items:center;
  gap:.65rem;
  flex:0 0 auto;
  color:var(--paper);
  text-decoration:none;
  transition:color var(--ease);
}
.brand:hover{color:#FFFFFF;}

.brand__mark{
  display:grid;
  place-items:center;
  width:36px;
  height:36px;
  border:1px solid var(--line-dark);
  border-radius:var(--radius-sm);
  background:rgba(46,230,214,.1);
  color:var(--cyan);
  font-family:var(--font-mono);
  font-size:.75rem;
  font-weight:700;
  letter-spacing:.06em;
}

.brand__text{
  display:flex;
  flex-direction:column;
  line-height:1.2;
}

.brand__name{
  font-size:1.0625rem;
  font-weight:800;
  letter-spacing:.02em;
}

.brand__tagline{
  font-size:.6875rem;
  letter-spacing:.2em;
  color:rgba(169,245,239,.66);
}

.site-nav{
  display:flex;
  align-items:center;
  gap:clamp(.5rem,1.8vw,1.5rem);
  margin-left:auto;
}

.site-nav__list{
  display:flex;
  align-items:center;
  gap:clamp(.15rem,1.2vw,1.1rem);
  margin:0;
  padding:0;
  list-style:none;
}

.site-nav__item{display:flex;}

.site-nav__link{
  position:relative;
  display:flex;
  align-items:baseline;
  gap:.35rem;
  padding:.55rem .35rem;
  border-radius:6px;
  color:rgba(224,240,250,.82);
  font-size:.9375rem;
  text-decoration:none;
  transition:color var(--ease),background var(--ease);
}
.site-nav__link:hover{color:var(--mist);background:rgba(46,230,214,.08);}
.site-nav__link::after{
  content:"";
  position:absolute;
  left:.35rem;
  right:.35rem;
  bottom:.22rem;
  height:1.5px;
  background:var(--cyan);
  transform:scaleX(0);
  transform-origin:left center;
  transition:transform var(--ease);
}
.site-nav__link:hover::after,
.site-nav__link[aria-current="page"]::after{transform:scaleX(1);}

.site-nav__link[aria-current="page"]{
  color:#FFFFFF;
  font-weight:700;
}
.site-nav__link[aria-current="page"] .site-nav__index{color:var(--amber);}

.site-nav__index{
  font-family:var(--font-mono);
  font-size:.625rem;
  letter-spacing:.08em;
  color:rgba(46,230,214,.62);
}

.site-nav__label{white-space:nowrap;}

.site-nav__cta{
  flex:0 0 auto;
  margin-left:.35rem;
}

.nav-toggle{
  display:none;
  align-items:center;
  gap:.55rem;
  padding:.5rem .8rem;
  border:1px solid rgba(169,245,239,.32);
  border-radius:var(--radius-sm);
  background:rgba(46,230,214,.09);
  color:var(--mist);
  font-size:.8125rem;
  letter-spacing:.08em;
  cursor:pointer;
  transition:background var(--ease),border-color var(--ease);
}
.nav-toggle:hover{background:rgba(46,230,214,.18);border-color:var(--cyan);}

.nav-toggle__bars{
  display:inline-flex;
  flex-direction:column;
  gap:4px;
  width:16px;
}
.nav-toggle__bars i{
  display:block;
  height:2px;
  border-radius:2px;
  background:currentColor;
  transition:transform var(--ease);
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars i:first-child{transform:translateY(3px) rotate(45deg);}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars i:last-child{transform:translateY(-3px) rotate(-45deg);}

.scroll-progress{
  position:absolute;
  left:0;
  right:0;
  bottom:-1px;
  height:2px;
  overflow:hidden;
  pointer-events:none;
}
.scroll-progress__fill{
  display:block;
  width:0;
  height:100%;
  background:linear-gradient(90deg,var(--teal) 0%,var(--cyan) 62%,var(--amber) 100%);
}

/* 6 页脚 ---------------------------------------------------------------- */
.site-footer{
  position:relative;
  margin-top:clamp(3rem,7vw,6rem);
  padding-top:clamp(2.5rem,6vw,4.25rem);
  background:
    radial-gradient(90% 70% at 90% 0%,rgba(46,230,214,.1) 0%,rgba(46,230,214,0) 60%),
    var(--deep);
  color:rgba(226,240,250,.8);
  border-top:1px solid rgba(46,230,214,.26);
}
.site-footer::before{
  content:"";
  position:absolute;
  inset:0 0 auto 0;
  height:1px;
  background:linear-gradient(90deg,transparent,var(--cyan),transparent);
  opacity:.55;
}

.site-footer__grid{
  display:grid;
  grid-template-columns:minmax(0,1.5fr) minmax(0,1fr) minmax(0,1.2fr);
  gap:clamp(1.75rem,4vw,3.5rem);
  width:100%;
  max-width:var(--max);
  margin-inline:auto;
  padding-inline:var(--gutter);
}

.site-footer__brandline{
  font-size:1.25rem;
  font-weight:800;
  letter-spacing:.04em;
  color:#F2FAFF;
}

.site-footer__summary{
  margin-top:.5rem;
  font-size:.9375rem;
  line-height:1.7;
  color:rgba(196,216,232,.84);
}

.site-footer__note{
  margin-top:1rem;
  max-width:34ch;
  font-size:.8125rem;
  line-height:1.7;
  color:rgba(146,170,188,.92);
  padding-left:.85rem;
  border-left:2px solid rgba(46,230,214,.45);
}

.footer-nav__title{
  font-family:var(--font-mono);
  font-size:.6875rem;
  letter-spacing:.22em;
  text-transform:uppercase;
  color:rgba(46,230,214,.8);
}

.footer-nav__list{
  display:grid;
  gap:.45rem;
  margin:.9rem 0 0;
  padding:0;
  list-style:none;
}

.footer-nav__link{
  color:rgba(226,240,250,.84);
  font-size:.9375rem;
  text-decoration:none;
  border-bottom:1px solid transparent;
  transition:color var(--ease),border-color var(--ease);
}
.footer-nav__link:hover{
  color:var(--cyan);
  border-bottom-color:currentColor;
}

.site-footer__contact{margin-top:0;}

.contact-list{
  display:grid;
  gap:.85rem;
  margin:.9rem 0 0;
  padding:0;
  list-style:none;
}

.contact-list li{display:grid;gap:.1rem;}

.contact-list__key{
  font-family:var(--font-mono);
  font-size:.6875rem;
  letter-spacing:.16em;
  text-transform:uppercase;
  color:rgba(46,230,214,.72);
}

.contact-list__value{
  font-size:.9375rem;
  line-height:1.65;
  color:#EAF4FC;
  overflow-wrap:anywhere;
}

.site-footer__bar{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  justify-content:space-between;
  gap:.5rem 1.75rem;
  width:100%;
  max-width:var(--max);
  margin:clamp(2rem,5vw,3.25rem) auto 0;
  padding:1.1rem var(--gutter) 1.6rem;
  border-top:1px solid rgba(169,245,239,.12);
  font-size:.8125rem;
  color:rgba(146,170,188,.92);
}

.site-footer__copy{margin:0;}

.site-footer__icp{
  font-family:var(--font-mono);
  font-size:.75rem;
  letter-spacing:.04em;
}

.footer-legal{
  display:flex;
  flex-wrap:wrap;
  gap:.4rem 1.1rem;
  margin:0;
  padding:0;
  list-style:none;
}

.footer-legal__link{
  color:rgba(226,240,250,.8);
  text-decoration:none;
  border-bottom:1px solid transparent;
  transition:color var(--ease),border-color var(--ease);
}
.footer-legal__link:hover{
  color:var(--cyan);
  border-bottom-color:currentColor;
}

/* 7 按钮 ---------------------------------------------------------------- */
.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:.5rem;
  padding:.85rem 1.35rem;
  border:1px solid transparent;
  border-radius:999px;
  font-family:var(--font-body);
  font-size:.9375rem;
  font-weight:700;
  line-height:1;
  letter-spacing:.02em;
  text-decoration:none;
  cursor:pointer;
  transition:transform var(--ease),background var(--ease),color var(--ease),border-color var(--ease);
}
.btn:active{transform:translateY(1px);}

.btn--amber{
  background:var(--amber);
  color:#241802;
  box-shadow:0 12px 26px -18px rgba(243,182,74,.95);
}
.btn--amber:hover{background:#FFC96A;}

.btn--cyan{
  background:var(--cyan);
  color:#04211F;
}
.btn--cyan:hover{background:#5CEEE2;}

.btn--ghost{
  background:transparent;
  border-color:rgba(169,245,239,.4);
  color:var(--mist);
}
.btn--ghost:hover{
  background:rgba(46,230,214,.12);
  border-color:var(--cyan);
  color:#FFFFFF;
}

/* 8 标签与索引 ---------------------------------------------------------- */
.tag{
  display:inline-flex;
  align-items:center;
  gap:.35rem;
  padding:.2rem .65rem;
  border:1px solid rgba(46,230,214,.42);
  border-radius:999px;
  background:rgba(46,230,214,.12);
  color:var(--teal);
  font-family:var(--font-mono);
  font-size:.75rem;
  letter-spacing:.06em;
}

.tag--amber{
  border-color:rgba(243,182,74,.55);
  background:rgba(243,182,74,.16);
  color:#7A5310;
}

.index-link{
  display:flex;
  align-items:center;
  gap:.6rem;
  padding:.45rem .6rem;
  border-left:2px solid transparent;
  border-radius:0 8px 8px 0;
  color:var(--slate);
  font-size:.875rem;
  text-decoration:none;
  transition:color var(--ease),background var(--ease),border-color var(--ease);
}
.index-link:hover{
  color:var(--ink);
  background:rgba(96,120,140,.1);
}
.index-link[data-active]{
  color:var(--ink);
  font-weight:700;
  border-left-color:var(--cyan);
  background:rgba(46,230,214,.14);
}

.section--dark .index-link{color:rgba(196,216,232,.82);}
.section--dark .index-link:hover{color:#FFFFFF;background:rgba(46,230,214,.1);}
.section--dark .index-link[data-active]{
  color:var(--mist);
  background:rgba(46,230,214,.16);
  border-left-color:var(--cyan);
}

/* 9 图片容器 ------------------------------------------------------------ */
.figure{
  position:relative;
  margin:0;
  overflow:hidden;
  border:1px solid rgba(46,230,214,.2);
  border-radius:var(--radius);
  background:linear-gradient(140deg,var(--blueprint) 0%,var(--deep) 100%);
  box-shadow:var(--shadow-soft);
}

.figure__media{
  display:block;
  width:100%;
  height:auto;
  aspect-ratio:16 / 9;
  object-fit:cover;
}

.figure__media:empty{
  background-image:
    repeating-linear-gradient(45deg,rgba(46,230,214,.09) 0 2px,transparent 2px 14px),
    repeating-linear-gradient(-45deg,rgba(169,245,239,.05) 0 1px,transparent 1px 26px);
}

.figure--tall .figure__media{aspect-ratio:4 / 5;}
.figure--square .figure__media{aspect-ratio:1 / 1;}

.figure--paper{
  border-color:rgba(96,120,140,.3);
  background:linear-gradient(140deg,#EFE7D8 0%,var(--paper) 100%);
  box-shadow:0 20px 50px -40px rgba(17,26,34,.9);
}

.figure__caption{
  position:absolute;
  left:0;
  right:0;
  bottom:0;
  margin:0;
  padding:.75rem 1rem;
  font-family:var(--font-mono);
  font-size:.75rem;
  letter-spacing:.05em;
  color:var(--mist);
  background:linear-gradient(180deg,rgba(8,24,38,0) 0%,rgba(8,24,38,.92) 100%);
}
.figure--paper .figure__caption{
  color:var(--ink);
  background:linear-gradient(180deg,rgba(243,237,225,0) 0%,rgba(243,237,225,.95) 100%);
}

/* 10 面包屑 ------------------------------------------------------------- */
.breadcrumb{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:.35rem .55rem;
  margin:0;
  padding:0;
  list-style:none;
  font-family:var(--font-mono);
  font-size:.75rem;
  letter-spacing:.06em;
  color:var(--slate);
}
.breadcrumb li{display:flex;align-items:center;gap:.55rem;}
.breadcrumb li + li::before{content:"/";color:rgba(96,120,140,.55);}
.breadcrumb a{
  color:inherit;
  text-decoration:none;
  border-bottom:1px solid transparent;
  transition:color var(--ease),border-color var(--ease);
}
.breadcrumb a:hover{color:var(--teal);border-bottom-color:currentColor;}
.breadcrumb [aria-current="page"]{color:var(--ink);font-weight:700;}
.section--dark .breadcrumb{color:rgba(160,186,205,.9);}
.section--dark .breadcrumb [aria-current="page"]{color:#EAF4FC;}

/* 11 回到顶部 ----------------------------------------------------------- */
.to-top{
  position:fixed;
  right:clamp(1rem,3vw,2rem);
  bottom:clamp(1rem,3vw,2rem);
  z-index:80;
  display:grid;
  place-items:center;
  width:46px;
  height:46px;
  padding:0;
  border:1px solid rgba(46,230,214,.5);
  border-radius:50%;
  background:rgba(8,24,38,.9);
  color:var(--mist);
  font-size:1rem;
  line-height:1;
  cursor:pointer;
  opacity:0;
  visibility:hidden;
  transform:translateY(10px);
  transition:opacity var(--ease),transform var(--ease),visibility var(--ease),background var(--ease);
}
.to-top[data-visible]{
  opacity:1;
  visibility:visible;
  transform:translateY(0);
}
.to-top:hover{background:var(--blueprint);border-color:var(--cyan);}

/* 12 响应式 ------------------------------------------------------------- */
@media (max-width:1240px){
  .site-nav__label{font-size:.875rem;}
  .brand__tagline{display:none;}
}

@media (max-width:1024px){
  .nav-toggle{display:inline-flex;}

  .site-nav{
    position:fixed;
    top:var(--header-h);
    right:0;
    bottom:0;
    left:auto;
    width:min(330px,88vw);
    flex-direction:column;
    align-items:stretch;
    gap:.25rem;
    margin-left:0;
    padding:1.25rem var(--gutter) 2rem;
    overflow-y:auto;
    background:var(--blueprint);
    border-left:1px solid rgba(46,230,214,.28);
    box-shadow:-30px 0 70px -40px #000;
    transform:translateX(100%);
    visibility:hidden;
    transition:transform 220ms ease,visibility 220ms ease;
  }
  .site-nav[data-open]{
    transform:translateX(0);
    visibility:visible;
  }

  .site-nav__list{
    flex-direction:column;
    align-items:stretch;
    gap:0;
  }
  .site-nav__item{display:block;}
  .site-nav__link{
    padding:.95rem .25rem;
    border-bottom:1px solid rgba(169,245,239,.12);
    font-size:1rem;
  }
  .site-nav__link::after{display:none;}
  .site-nav__link[aria-current="page"]{color:var(--cyan);}
  .site-nav__cta{
    margin:1rem 0 0;
    justify-content:center;
    width:100%;
  }

  .site-footer__grid{grid-template-columns:minmax(0,1fr) minmax(0,1fr);}
  .site-footer__brand{grid-column:1 / -1;}
}

@media (max-width:760px){
  :root{--header-h:66px;}
  body{line-height:1.72;}
  .site-footer__grid{grid-template-columns:1fr;gap:1.9rem;}
  .site-footer__bar{
    flex-direction:column;
    align-items:flex-start;
    gap:.55rem;
  }
  .figure__caption{font-size:.6875rem;padding:.6rem .8rem;}
  .to-top{width:42px;height:42px;}
}

@media (max-width:480px){
  .brand__name{font-size:1rem;}
  .btn{width:100%;}
  .site-nav__cta{width:100%;}
  .nav-toggle__text{display:none;}
}

/* 13 动效降级 ----------------------------------------------------------- */
[data-reveal]{
  transition:opacity 420ms ease,transform 420ms ease;
}
.is-hidden{
  opacity:0;
  transform:translateY(14px);
}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto;}
  *,
  *::before,
  *::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
    scroll-behavior:auto !important;
  }
  .is-hidden{opacity:1;transform:none;}
  .site-nav{transition:none;}
}