:root{
  --color-deep-space:#0B1F3A;
  --color-deep-space-2:#1A2B4C;
  --color-snow:#F7F9FC;
  --color-gold:#D4AF37;
  --color-light-gold:#F2E3A0;
  --color-stone:#8A8F98;
  --color-moss:#6B8E6B;
  --color-terra:#B5651D;
  --color-ink:#0A0E17;
  --font-head:'Inter Tight','Arial Black','PingFang SC','Microsoft YaHei',sans-serif;
  --font-body:'Inter','PingFang SC','Hiragino Sans GB','Microsoft YaHei',sans-serif;
  --font-mono:'JetBrains Mono','SFMono-Regular',Consolas,'Liberation Mono',monospace;
  --sidebar-w:300px;
  --container-w:1180px;
  --shadow:0 12px 40px rgba(10,14,23,.08);
  --ease:cubic-bezier(.25,.1,.25,1);
}

*, *::before, *::after{ box-sizing:border-box; margin:0; padding:0; }

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

body{
  min-height:100vh;
  display:grid;
  grid-template-columns:var(--sidebar-w) 1fr;
  grid-template-rows:1fr auto;
  background:var(--color-snow);
  color:var(--color-ink);
  font-family:var(--font-body);
  font-size:1rem;
  line-height:1.7;
  overflow-x:hidden;
}

h1,h2,h3,h4{
  font-family:var(--font-head);
  font-weight:800;
  letter-spacing:-0.02em;
  line-height:1.15;
}

ul,ol{ list-style:none; }

a{ color:inherit; text-decoration:none; }

button{
  font-family:inherit;
  background:none;
  border:0;
  cursor:pointer;
}

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

input, button{ color:inherit; }

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

[id="main-content"]{
  grid-column:2;
  grid-row:1;
  min-width:0;
  outline:none;
  padding:clamp(1.5rem, 3vw, 3rem) 0;
}

/* 容器 */
.container{
  width:min(100% - 2.5rem, var(--container-w));
  margin-inline:auto;
}

/* 网格 */
.grid{ display:grid; gap:1.5rem; }
.grid--2{ grid-template-columns:repeat(2, minmax(0,1fr)); }
.grid--3{ grid-template-columns:repeat(3, minmax(0,1fr)); }

/* 图片占位 */
.image-placeholder{
  display:flex;
  align-items:center;
  justify-content:center;
  min-height:180px;
  background:linear-gradient(135deg, #dbe3ec 0%, #c3cedb 100%);
  color:var(--color-stone);
  font-family:var(--font-mono);
  font-size:.85rem;
  border:1px solid var(--color-stone);
  position:relative;
  overflow:hidden;
}
.image-placeholder::after{
  content:attr(data-ratio);
  position:absolute;
  right:.75rem;
  bottom:.5rem;
  font-size:.75rem;
  color:var(--color-stone);
  opacity:.8;
}
.image-placeholder--dark{
  background:linear-gradient(135deg, var(--color-deep-space) 0%, var(--color-deep-space-2) 100%);
  color:var(--color-snow);
  border-color:rgba(247,249,252,.15);
}
.image-placeholder--tall{ min-height:320px; }

/* 按钮 */
.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:.5rem;
  padding:.8rem 1.4rem;
  background:var(--color-gold);
  color:var(--color-deep-space);
  font-weight:700;
  font-family:var(--font-head);
  font-size:1rem;
  letter-spacing:-.01em;
  clip-path:polygon(0 0, calc(100% - 12px) 0, 100% 12px, 100% 100%, 0 100%);
  border:0;
  transition:background .2s var(--ease), transform .2s var(--ease), box-shadow .2s var(--ease);
}
.btn:hover{
  background:var(--color-light-gold);
  transform:translateY(-1px);
  box-shadow:0 6px 16px rgba(11,31,58,.15);
}
.btn--ghost{
  background:transparent;
  border:1px solid var(--color-gold);
  color:var(--color-gold);
}
.btn--ghost:hover{
  background:rgba(212,175,55,.12);
  color:var(--color-light-gold);
}
.btn--dark{
  background:var(--color-deep-space);
  color:var(--color-snow);
}
.btn--dark:hover{
  background:var(--color-deep-space-2);
  color:var(--color-light-gold);
}

/* 标签 */
.tag{
  display:inline-flex;
  padding:.25rem .75rem;
  font-size:.85rem;
  font-weight:600;
  background:rgba(212,175,55,.12);
  color:var(--color-terra);
  border:1px solid rgba(212,175,55,.35);
}
.tag--moss{
  background:rgba(107,142,107,.12);
  border-color:rgba(107,142,107,.35);
  color:var(--color-moss);
}

/* 章节标题 */
.section-heading{
  font-size:clamp(2rem, 4vw, 3.25rem);
  margin-bottom:1rem;
  position:relative;
}
.section-heading::before{
  content:"";
  display:block;
  width:48px;
  height:4px;
  background:var(--color-gold);
  margin-bottom:.75rem;
}
.section-heading__eyebrow{
  display:block;
  font-family:var(--font-mono);
  font-size:.85rem;
  font-weight:700;
  letter-spacing:.2em;
  text-transform:uppercase;
  color:var(--color-gold);
  margin-bottom:.5rem;
}
.section-heading--light{ color:var(--color-snow); }

/* 面包屑 */
.breadcrumb{
  display:flex;
  flex-wrap:wrap;
  gap:.5rem;
  padding:.75rem 0;
  font-size:.92rem;
  color:var(--color-stone);
}
.breadcrumb li + li::before{
  content:"/";
  margin-right:.5rem;
  color:var(--color-stone);
}
.breadcrumb a{
  color:var(--color-deep-space);
  border-bottom:1px solid transparent;
  transition:border-color .2s var(--ease), color .2s var(--ease);
}
.breadcrumb a:hover{
  color:var(--color-gold);
  border-bottom-color:var(--color-gold);
}

/* 卡片 */
.card{
  background:var(--color-snow);
  border:1px solid var(--color-stone);
  padding:1.5rem;
  position:relative;
}
.card--alt{
  background:linear-gradient(135deg, var(--color-deep-space), var(--color-deep-space-2));
  color:var(--color-snow);
  border-color:transparent;
}
.card--cut{
  clip-path:polygon(0 0, calc(100% - 1.25rem) 0, 100% 1.25rem, 100% 100%, 0 100%);
}

/* 头部 */
.site-header{
  grid-column:1;
  grid-row:1 / 3;
  position:sticky;
  top:0;
  height:100vh;
  z-index:500;
  align-self:start;
  isolation:isolate;
}
.site-header__panel{
  position:relative;
  display:flex;
  flex-direction:column;
  height:100vh;
  padding:clamp(1.5rem, 3vw, 2.5rem) 1.5rem 1.5rem 2rem;
  background:linear-gradient(135deg, #0B1F3A 0%, #1A2B4C 100%);
  color:var(--color-snow);
  clip-path:polygon(0 0, calc(100% - 2rem) 0, 100% 2rem, 100% 100%, 0 100%);
}
.site-header__panel::before{
  content:"";
  position:absolute;
  inset:0;
  background:repeating-linear-gradient(115deg, transparent 0 12px, rgba(255,255,255,.02) 12px 13px);
  pointer-events:none;
}
.site-header__panel::after{
  content:"";
  position:absolute;
  top:2rem;
  right:1.5rem;
  width:5rem;
  height:5rem;
  border-top:2px solid rgba(212,175,55,.4);
  border-right:2px solid rgba(212,175,55,.4);
  opacity:.6;
}

.skip-link{
  position:fixed;
  top:1rem;
  left:calc(var(--sidebar-w) + 1rem);
  z-index:2000;
  padding:.75rem 1.25rem;
  background:var(--color-gold);
  color:var(--color-deep-space);
  font-weight:700;
  transform:translateY(-300%);
  transition:transform .2s var(--ease);
}
.skip-link:focus{
  transform:translateY(0);
}

.nav-toggle{
  display:none;
}

/* 品牌 */
.site-brand{
  display:inline-flex;
  align-items:center;
  gap:.75rem;
  color:var(--color-snow);
}
.site-brand__mark{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  width:3.25rem;
  height:3.25rem;
  background:var(--color-gold);
  color:var(--color-deep-space);
  font-family:var(--font-head);
  font-size:1.5rem;
  font-weight:800;
  clip-path:polygon(0 0, calc(100% - 8px) 0, 100% 8px, 100% 100%, 0 100%);
  transform:skewY(-2deg);
}
.site-brand__name{
  display:block;
  font-size:1.75rem;
  line-height:1;
}
.site-brand__tag{
  display:block;
  font-size:.7rem;
  letter-spacing:.22em;
  text-transform:uppercase;
  color:var(--color-light-gold);
  margin-top:.15rem;
}

/* 导航 */
.site-nav{
  margin-top:2rem;
}
.site-nav__list{
  counter-reset:route-counter;
  display:flex;
  flex-direction:column;
  gap:.15rem;
}
.site-nav__item{
  counter-increment:route-counter;
}
.site-nav__item a{
  position:relative;
  display:flex;
  align-items:center;
  gap:.8rem;
  padding:.65rem .9rem;
  color:var(--color-snow);
  font-weight:600;
  border-left:2px solid transparent;
  transition:background .18s var(--ease), border-color .18s var(--ease), color .18s var(--ease);
}
.site-nav__item a::before{
  content:"/" counter(route-counter, decimal-leading-zero);
  font-family:var(--font-mono);
  font-size:.78rem;
  font-weight:700;
  color:var(--color-stone);
  opacity:.85;
  transition:color .18s;
}
.site-nav__item a:hover{
  background:rgba(212,175,55,.08);
  border-left-color:var(--color-gold);
  color:var(--color-light-gold);
}
.site-nav__item a[aria-current="page"]{
  background:linear-gradient(90deg, rgba(212,175,55,.16), transparent 80%);
  border-left-color:var(--color-gold);
  color:var(--color-gold);
}
.site-nav__item a[aria-current="page"]::before{
  color:var(--color-gold);
}

/* 头部工具 */
.site-header__tools{
  margin-top:auto;
  padding-top:1.5rem;
  display:flex;
  flex-direction:column;
  gap:.85rem;
}
.search-field{
  display:flex;
  align-items:center;
  gap:.6rem;
  padding:.35rem .65rem;
  border:1px solid rgba(247,249,252,.18);
  background:rgba(247,249,252,.06);
  clip-path:polygon(0 0, calc(100% - 10px) 0, 100% 10px, 100% 100%, 0 100%);
  transition:border-color .2s var(--ease), box-shadow .2s var(--ease);
}
.search-field:focus-within{
  border-color:var(--color-gold);
  box-shadow:0 0 0 1px var(--color-gold);
}
.search-field__icon{
  color:var(--color-gold);
  font-size:1.1rem;
  line-height:1;
}
.search-field__input{
  flex:1;
  min-width:0;
  padding:.2rem 0;
  background:transparent;
  border:0;
  outline:none;
  color:var(--color-snow);
  font-family:var(--font-body);
  font-size:.9rem;
}
.search-field__input::placeholder{
  color:var(--color-stone);
  opacity:.9;
}
.help-link{
  align-self:flex-start;
  color:var(--color-light-gold);
  font-size:.9rem;
  border-bottom:1px solid transparent;
  padding-bottom:.1rem;
  transition:color .2s, border-color .2s;
}
.help-link:hover{
  color:var(--color-gold);
  border-color:var(--color-gold);
}

.site-header__foot{
  display:flex;
  justify-content:space-between;
  gap:1rem;
  margin-top:1.25rem;
  padding-top:.75rem;
  border-top:1px solid rgba(247,249,252,.12);
  font-family:var(--font-mono);
  font-size:.75rem;
  color:var(--color-stone);
}

/* 滚动进度 */
.scroll-progress{
  position:fixed;
  top:0;
  left:var(--sidebar-w);
  right:0;
  height:3px;
  background:rgba(212,175,55,.12);
  z-index:1000;
  pointer-events:none;
}
.scroll-progress::after{
  content:"";
  display:block;
  height:100%;
  width:var(--progress, 0%);
  background:linear-gradient(90deg, var(--color-gold), var(--color-light-gold));
}

/* 页脚 */
.site-footer{
  grid-column:2;
  grid-row:2;
  background:linear-gradient(135deg, #0B1F3A 0%, #1A2B4C 100%);
  color:var(--color-snow);
  position:relative;
  border-top:3px solid var(--color-gold);
}
.site-footer::before{
  content:"";
  display:block;
  height:6px;
  background:linear-gradient(90deg, var(--color-gold) 0%, var(--color-deep-space) 30%, var(--color-gold) 60%, rgba(107,142,107,.6) 80%, var(--color-deep-space) 100%);
}
.site-footer__inner{
  max-width:calc(var(--container-w) + 4rem);
  margin:0 auto;
  padding:2.5rem 1.5rem 1rem;
  display:grid;
  grid-template-columns:minmax(200px, 1.4fr) repeat(3, minmax(0,1fr));
  gap:2rem;
}
.site-footer__brand{
  display:flex;
  flex-direction:column;
  align-items:flex-start;
  gap:.25rem;
}
.site-footer__desc{
  margin-top:.65rem;
  font-size:.92rem;
  color:rgba(247,249,252,.7);
  max-width:34ch;
}
.site-brand--footer .site-brand__mark{
  background:transparent;
  border:1px solid var(--color-gold);
  color:var(--color-gold);
}
.site-brand--footer .site-brand__name{
  color:var(--color-snow);
}
.site-brand--footer .site-brand__tag{
  color:var(--color-stone);
}
.site-footer__cols{
  grid-column:2 / -1;
  display:grid;
  grid-template-columns:repeat(3, minmax(0,1fr));
  gap:2rem;
}
.site-footer__heading{
  font-size:1rem;
  letter-spacing:.12em;
  text-transform:uppercase;
  color:var(--color-gold);
  margin-bottom:1rem;
  padding-left:.5rem;
  border-left:3px solid var(--color-gold);
}
.site-footer__col ul{
  display:flex;
  flex-direction:column;
  gap:.45rem;
}
.site-footer__col a{
  color:var(--color-snow);
  opacity:.82;
  transition:opacity .2s, color .2s;
}
.site-footer__col a:hover{
  color:var(--color-light-gold);
  opacity:1;
}
.site-footer__contact{
  font-size:.9rem;
  color:rgba(247,249,252,.7);
  line-height:1.6;
}
.site-footer__meta{
  grid-column:1 / -1;
  margin-top:1.5rem;
  padding-top:1.25rem;
  border-top:1px solid rgba(247,249,252,.15);
  display:flex;
  flex-wrap:wrap;
  justify-content:space-between;
  gap:1rem;
  font-size:.85rem;
  color:var(--color-stone);
}
.site-footer__meta p{
  margin:0;
}

/* 移动端 */
@media (max-width:1024px){
  body{
    display:block;
  }
  .site-header{
    position:fixed;
    top:0;
    left:0;
    right:0;
    height:auto;
    z-index:1000;
    background:transparent;
  }
  .site-header__panel{
    position:fixed;
    top:0;
    left:0;
    bottom:0;
    width:min(85vw, 320px);
    height:100vh;
    transform:translateX(-105%);
    transition:transform .25s var(--ease);
    box-shadow:4px 0 24px rgba(0,0,0,.3);
  }
  .site-header__panel[data-open]{
    transform:translateX(0);
  }
  .nav-toggle{
    display:flex;
    position:fixed;
    top:.75rem;
    right:.75rem;
    z-index:1001;
    align-items:center;
    gap:.4rem;
    padding:.55rem .8rem;
    background:var(--color-gold);
    color:var(--color-deep-space);
    font-weight:700;
    font-family:var(--font-head);
    clip-path:polygon(0 0, calc(100% - 8px) 0, 100% 8px, 100% 100%, 0 100%);
  }
  .nav-toggle__lines{
    position:relative;
    display:inline-block;
    width:1.1rem;
    height:2px;
    background:currentColor;
    transition:background .2s;
  }
  .nav-toggle__lines::before,
  .nav-toggle__lines::after{
    content:"";
    position:absolute;
    left:0;
    width:100%;
    height:2px;
    background:currentColor;
    transition:transform .2s var(--ease);
  }
  .nav-toggle__lines::before{
    top:-5px;
  }
  .nav-toggle__lines::after{
    top:5px;
  }
  .site-header[data-nav-open] .nav-toggle__lines{
    background:transparent;
  }
  .site-header[data-nav-open] .nav-toggle__lines::before{
    transform:translateY(5px) rotate(45deg);
  }
  .site-header[data-nav-open] .nav-toggle__lines::after{
    transform:translateY(-5px) rotate(-45deg);
  }
  .skip-link{
    left:1rem;
  }
  .scroll-progress{
    left:0;
  }
  body.nav-open{
    overflow:hidden;
  }
  .site-footer__inner{
    grid-template-columns:1fr;
  }
  .site-footer__cols{
    grid-column:1;
    grid-template-columns:1fr 1fr;
  }
  .site-footer__meta{
    grid-column:1;
    flex-direction:column;
  }
  .grid--2, .grid--3{
    grid-template-columns:1fr;
  }
}

@media (max-width:640px){
  .site-footer__cols{
    grid-template-columns:1fr;
  }
  .image-placeholder{
    min-height:140px;
  }
}

@media (prefers-reduced-motion: reduce){
  *, *::before, *::after{
    animation-duration:.01ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.01ms !important;
  }
  html{
    scroll-behavior:auto;
  }
}