*,*::before,*::after{box-sizing:border-box}
*{margin:0}
html{scroll-behavior:smooth;scroll-padding-top:calc(var(--header-h) + 12px);-webkit-text-size-adjust:100%}

:root{
  --c-ink:#0A1428;
  --c-cobalt:#17315C;
  --c-gold:#F5B23E;
  --c-violet:#7B5CFF;
  --c-flame:#FF6E4A;
  --c-paper:#F7F9FC;
  --c-silver:#C6CDDA;
  --c-char:#242B38;
  --c-reading:#E6EAF2;
  --c-wine:#9C2542;

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

  --max-w:1440px;
  --gutter:clamp(20px,4vw,64px);
  --header-h:72px;

  --r-sm:6px;
  --r-md:12px;
  --r-lg:20px;

  --ease:0.25s cubic-bezier(0.4,0,0.2,1)
}

body{
  font-family:var(--font-body);
  font-weight:400;
  font-size:16px;
  line-height:1.7;
  color:var(--c-char);
  background:var(--c-paper);
  padding-top:var(--header-h);
  min-width:320px
}

main{display:block}

img,svg,video{max-width:100%;display:block;height:auto}
ul,ol{list-style:none;margin:0;padding:0}
a{color:inherit;text-decoration:none}
button{font:inherit;border:0;background:none;cursor:pointer}

.container{
  width:min(100% - var(--gutter) * 2,var(--max-w));
  margin-inline:auto
}

.skip-link{
  position:fixed;
  top:10px;
  left:10px;
  z-index:9999;
  background:var(--c-gold);
  color:var(--c-ink);
  font-weight:700;
  font-size:14px;
  padding:10px 18px;
  border-radius:var(--r-sm);
  transform:translateY(-200%);
  transition:transform 0.2s ease
}
.skip-link:focus{transform:translateY(0)}

.scroll-progress{
  position:absolute;
  top:0;
  left:0;
  right:0;
  height:3px;
  background:var(--c-gold);
  transform:scaleX(0);
  transform-origin:0 50%;
  z-index:910;
  pointer-events:none
}

.site-header{
  position:fixed;
  top:0;
  left:0;
  right:0;
  z-index:900;
  background:rgba(10,20,40,0.96);
  border-bottom:1px solid rgba(198,205,218,0.14)
}

.site-header__inner{
  display:flex;
  align-items:center;
  justify-content:space-between;
  height:var(--header-h);
  gap:24px
}

.brand{
  display:inline-flex;
  align-items:center;
  gap:10px;
  flex-shrink:0
}
.brand__name{
  color:var(--c-paper);
  font-family:var(--font-sans);
  font-weight:700;
  font-size:20px;
  letter-spacing:0.08em;
  line-height:1.2
}
.brand__tag{
  font-family:var(--font-mono);
  font-weight:700;
  font-size:13px;
  color:var(--c-gold);
  border:1px solid var(--c-gold);
  border-radius:4px;
  padding:2px 6px;
  line-height:1.3;
  letter-spacing:0.05em
}
.brand--footer .brand__name{font-size:24px}

.site-nav{
  display:flex;
  align-items:center;
  gap:8px
}
.site-nav__list{
  display:flex;
  align-items:center;
  gap:2px
}
.site-nav__link{
  display:inline-flex;
  align-items:baseline;
  gap:6px;
  padding:8px 12px;
  color:var(--c-reading);
  font-size:15px;
  font-weight:500;
  position:relative;
  transition:color var(--ease);
  border-radius:var(--r-sm);
  white-space:nowrap
}
.site-nav__link::after{
  content:"";
  position:absolute;
  left:12px;
  right:calc(100% - 12px);
  bottom:2px;
  height:2px;
  background:linear-gradient(90deg,var(--c-gold),transparent);
  transition:right var(--ease)
}
.site-nav__link:hover{color:var(--c-gold)}
.site-nav__link:hover::after,
.site-nav__link[aria-current="page"]::after{right:12px}
.site-nav__link[aria-current="page"]{color:var(--c-gold)}
.site-nav__index{
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:0.03em;
  color:var(--c-gold);
  opacity:0.6;
  line-height:1
}
.site-nav__title{display:inline-block;line-height:1.3}
.site-nav__cta{margin-left:12px;flex-shrink:0}

.nav-toggle{
  display:none;
  position:relative;
  z-index:1010;
  flex-direction:column;
  align-items:center;
  gap:4px;
  padding:8px 12px;
  border:1px solid rgba(198,205,218,0.4);
  border-radius:var(--r-sm);
  background:transparent
}
.nav-toggle__bars{display:flex;flex-direction:column;gap:5px;width:20px}
.nav-toggle__bar{
  display:block;
  height:2px;
  background:var(--c-gold);
  border-radius:2px;
  transition:transform var(--ease)
}
.nav-toggle__text{
  font-size:11px;
  color:var(--c-reading);
  letter-spacing:0.08em
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(1){transform:translateY(3.5px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(2){transform:translateY(-3.5px) rotate(-45deg)}

.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:8px;
  padding:12px 26px;
  border-radius:999px;
  font-family:var(--font-body);
  font-size:15px;
  font-weight:600;
  line-height:1.2;
  text-decoration:none;
  transition:background-color var(--ease),color var(--ease),border-color var(--ease),transform var(--ease)
}
.btn--primary{
  background:var(--c-gold);
  color:var(--c-ink)
}
.btn--primary:hover{
  background:var(--c-wine);
  color:var(--c-paper)
}
.btn--ghost{
  border:1.5px solid var(--c-silver);
  color:var(--c-reading);
  background:transparent
}
.btn--ghost:hover{
  border-color:var(--c-violet);
  color:var(--c-violet)
}

.breadcrumb{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  font-family:var(--font-mono);
  font-size:13px;
  color:rgba(198,205,218,0.8);
  list-style:none
}
.breadcrumb__item{display:inline-flex;align-items:center}
.breadcrumb__item + .breadcrumb__item::before{
  content:"/";
  color:rgba(198,205,218,0.5);
  margin:0 10px
}
.breadcrumb__link{
  color:rgba(198,205,218,0.8);
  text-decoration:none;
  transition:color var(--ease)
}
.breadcrumb__link:hover{color:var(--c-gold)}
.breadcrumb__current{
  color:var(--c-reading);
  font-weight:500
}

.page-head{
  background:
    radial-gradient(60% 120% at 90% 0%,rgba(23,49,92,0.85) 0%,rgba(10,20,40,0) 60%),
    var(--c-ink);
  padding:48px 0 64px;
  color:var(--c-reading);
  position:relative;
  overflow:hidden
}
.page-head::after{
  content:"";
  position:absolute;
  right:-80px;
  top:-80px;
  width:280px;
  height:280px;
  background:var(--c-cobalt);
  border-radius:50%;
  opacity:0.4;
  pointer-events:none
}
.page-head__title{
  font-family:var(--font-sans);
  font-size:clamp(36px,6vw,64px);
  font-weight:900;
  line-height:1.08;
  color:var(--c-paper);
  letter-spacing:-0.02em;
  margin-top:20px;
  position:relative;
  z-index:1
}
.page-head__lede{
  font-size:16px;
  color:var(--c-silver);
  max-width:42em;
  margin-top:14px;
  position:relative;
  z-index:1
}

.section-heading{
  display:flex;
  align-items:baseline;
  gap:16px;
  margin-bottom:32px
}
.section-heading__index{
  font-family:var(--font-mono);
  font-size:14px;
  color:var(--c-gold);
  letter-spacing:0.06em;
  line-height:1
}
.section-heading__title{
  font-family:var(--font-sans);
  font-size:clamp(26px,3.6vw,42px);
  font-weight:800;
  line-height:1.2;
  color:var(--c-ink);
  letter-spacing:-0.01em
}
.section-heading__line{
  flex:1;
  height:1px;
  align-self:center;
  background:linear-gradient(90deg,var(--c-silver),transparent)
}
.section-heading--dark .section-heading__title{color:var(--c-paper)}

.toc{
  position:sticky;
  top:calc(var(--header-h) + 24px);
  padding:20px 0
}
.toc__title{
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:0.16em;
  color:var(--c-silver);
  text-transform:uppercase;
  padding-bottom:10px;
  border-bottom:1px solid rgba(198,205,218,0.25)
}
.toc__list{
  margin-top:12px;
  display:flex;
  flex-direction:column;
  gap:6px
}
.toc__link{
  display:inline-flex;
  align-items:baseline;
  gap:8px;
  font-size:14px;
  color:var(--c-silver);
  padding:4px 0;
  border-bottom:1px solid transparent;
  transition:color var(--ease),border-color var(--ease)
}
.toc__link:hover{color:var(--c-gold)}
.toc__link[aria-current="true"]{
  color:var(--c-gold);
  border-bottom-color:var(--c-gold)
}
.toc__index{
  font-family:var(--font-mono);
  font-size:11px;
  color:var(--c-gold);
  opacity:0.7
}

.card-grid{
  display:grid;
  grid-template-columns:repeat(auto-fill,minmax(min(100%,300px),1fr));
  gap:24px
}
.content-card{
  background:var(--c-paper);
  border:1px solid var(--c-silver);
  border-radius:var(--r-lg);
  padding:28px;
  transition:border-color var(--ease),box-shadow var(--ease),transform var(--ease)
}
.content-card:hover{
  border-color:var(--c-gold);
  box-shadow:0 12px 32px rgba(10,20,40,0.08);
  transform:translateY(-2px)
}
.content-card--dark{
  background:var(--c-cobalt);
  border-color:rgba(198,205,218,0.15);
  color:var(--c-reading)
}
.content-card--dark:hover{
  border-color:var(--c-gold);
  box-shadow:0 12px 32px rgba(10,20,40,0.35)
}

.prose{
  max-width:72em;
  line-height:1.9;
  color:var(--c-char)
}
.prose p{
  margin-bottom:1.4em
}
.prose h2,
.prose h3{
  font-family:var(--font-sans);
  font-weight:700;
  line-height:1.3;
  margin-top:2.2em;
  margin-bottom:0.6em;
  color:var(--c-ink)
}
.prose h2{font-size:28px}
.prose h3{font-size:21px}
.prose a{
  color:var(--c-gold);
  text-decoration:underline;
  text-underline-offset:3px
}
.prose ul{
  list-style:disc;
  padding-left:1.5em;
  margin-bottom:1.4em
}
.prose blockquote{
  border-left:3px solid var(--c-gold);
  padding-left:16px;
  color:var(--c-char);
  font-style:italic
}

.site-footer{
  background:var(--c-ink);
  color:var(--c-reading);
  padding:72px 0 0;
  position:relative;
  overflow:hidden
}
.site-footer::before{
  content:"";
  position:absolute;
  top:0;
  left:0;
  right:0;
  height:1px;
  background:linear-gradient(90deg,var(--c-gold) 0%,transparent 55%)
}
.site-footer::after{
  content:"NG";
  position:absolute;
  right:-40px;
  bottom:-70px;
  font-family:var(--font-sans);
  font-size:240px;
  font-weight:900;
  color:rgba(245,178,62,0.04);
  line-height:1;
  pointer-events:none;
  user-select:none
}

.site-footer__grid{
  display:grid;
  grid-template-columns:2fr 1fr 1fr 1.4fr;
  gap:48px;
  padding-bottom:64px;
  position:relative;
  z-index:1
}
.site-footer__brand-block{
  display:flex;
  flex-direction:column;
  gap:16px;
  align-items:flex-start
}
.site-footer__about{
  font-size:14px;
  line-height:1.8;
  color:var(--c-silver);
  max-width:340px
}
.site-footer__trust{
  font-size:12px;
  line-height:1.7;
  color:rgba(198,205,218,0.6);
  max-width:340px;
  border-left:2px solid var(--c-gold);
  padding-left:12px
}
.site-footer__navcol{
  display:flex;
  flex-direction:column
}
.site-footer__heading{
  font-size:14px;
  font-weight:600;
  color:var(--c-paper);
  letter-spacing:0.14em;
  padding-bottom:12px;
  margin-bottom:20px;
  position:relative
}
.site-footer__heading::after{
  content:"";
  position:absolute;
  left:0;
  bottom:0;
  width:28px;
  height:2px;
  background:var(--c-gold)
}
.site-footer__links{
  display:flex;
  flex-direction:column;
  gap:10px
}
.site-footer__links a{
  color:var(--c-silver);
  font-size:14px;
  transition:color var(--ease),padding-left var(--ease)
}
.site-footer__links a:hover{
  color:var(--c-gold);
  padding-left:4px
}
.site-footer__contact{
  display:flex;
  flex-direction:column;
  gap:14px
}
.site-footer__contact-row{
  display:flex;
  flex-direction:column;
  gap:2px
}
.site-footer__contact-label{
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:0.1em;
  color:var(--c-gold);
  opacity:0.7
}
.site-footer__contact-value{
  font-size:14px;
  color:var(--c-reading);
  line-height:1.5;
  overflow-wrap:break-word
}
.site-footer__bottom{
  border-top:1px solid rgba(198,205,218,0.14);
  padding:24px 0;
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  justify-content:space-between;
  gap:12px;
  position:relative;
  z-index:1
}
.site-footer__copyright,
.site-footer__icp{
  font-family:var(--font-mono);
  font-size:12px;
  color:rgba(198,205,218,0.6)
}
.site-footer__legal{
  display:flex;
  gap:20px
}
.site-footer__legal a{
  font-size:12px;
  color:rgba(198,205,218,0.6);
  transition:color var(--ease)
}
.site-footer__legal a:hover{
  color:var(--c-gold)
}

.back-to-top{
  position:fixed;
  right:32px;
  bottom:96px;
  z-index:950;
  width:48px;
  height:48px;
  border-radius:50%;
  border:1.5px solid var(--c-gold);
  background:rgba(10,20,40,0.85);
  color:var(--c-gold);
  font-size:20px;
  display:flex;
  align-items:center;
  justify-content:center;
  opacity:0;
  visibility:hidden;
  transform:translateY(8px);
  transition:opacity var(--ease),visibility 0s linear 0.25s,transform var(--ease),background-color var(--ease)
}
.back-to-top[data-visible="true"]{
  opacity:1;
  visibility:visible;
  transform:translateY(0);
  transition:opacity var(--ease),transform var(--ease)
}
.back-to-top:hover{
  background:var(--c-gold);
  color:var(--c-ink)
}
.back-to-top__icon{
  line-height:1
}

.fab-feedback{
  position:fixed;
  right:24px;
  bottom:24px;
  z-index:950;
  display:inline-flex;
  align-items:center;
  gap:8px;
  padding:14px 22px;
  background:var(--c-gold);
  color:var(--c-ink);
  font-size:14px;
  font-weight:700;
  border-radius:999px;
  box-shadow:0 8px 24px rgba(245,178,62,0.4);
  transition:background-color var(--ease),transform var(--ease),box-shadow var(--ease)
}
.fab-feedback:hover{
  background:var(--c-wine);
  color:var(--c-paper);
  transform:translateY(-2px);
  box-shadow:0 12px 28px rgba(156,37,66,0.35)
}
.fab-feedback__text{line-height:1.2}
.fab-feedback__badge{
  width:8px;
  height:8px;
  border-radius:50%;
  background:var(--c-flame);
  box-shadow:0 0 0 3px rgba(255,110,74,0.25);
  flex-shrink:0
}

body.nav-lock{
  overflow:hidden
}

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

@media (max-width:1100px){
  .site-footer__grid{
    grid-template-columns:1fr 1fr;
    gap:40px
  }
}

@media (max-width:900px){
  :root{
    --header-h:64px
  }
  .site-nav{
    position:fixed;
    inset:0;
    z-index:1000;
    background:rgba(10,20,40,0.98);
    flex-direction:column;
    justify-content:center;
    align-items:center;
    gap:24px;
    padding:80px 24px 40px;
    opacity:0;
    visibility:hidden;
    transform:translateY(-10px);
    transition:opacity 0.3s ease,transform 0.3s ease,visibility 0s linear 0.3s
  }
  .site-nav[data-open]{
    opacity:1;
    visibility:visible;
    transform:translateY(0);
    transition:opacity 0.3s ease,transform 0.3s ease
  }
  .site-nav__list{
    flex-direction:column;
    width:100%;
    max-width:400px;
    gap:4px
  }
  .site-nav__link{
    font-size:22px;
    font-weight:700;
    padding:14px 16px;
    width:100%
  }
  .site-nav__index{
    font-size:13px
  }
  .site-nav__cta{
    margin:12px 0 0;
    width:100%;
    max-width:400px
  }
  .nav-toggle{
    display:inline-flex
  }
  .site-header__inner{
    gap:12px
  }
}

@media (max-width:640px){
  .site-footer__grid{
    grid-template-columns:1fr;
    gap:36px
  }
  .site-footer__bottom{
    flex-direction:column;
    align-items:flex-start;
    gap:8px
  }
  .fab-feedback{
    right:16px;
    bottom:16px;
    padding:12px 18px;
    font-size:13px
  }
  .back-to-top{
    right:22px;
    bottom:76px;
    width:42px;
    height:42px;
    font-size:18px
  }
  .site-footer::after{
    font-size:180px;
    right:-30px;
    bottom:-50px
  }
}

@media (prefers-reduced-motion:reduce){
  *,*::before,*::after{
    animation-duration:0.01ms !important;
    animation-iteration-count:1 !important;
    transition-duration:0.01ms !important;
    scroll-behavior:auto !important
  }
  html{
    scroll-behavior:auto
  }
}