:root{
  --ink:#0A1020;
  --indigo:#101B33;
  --indigo-2:#1C3050;
  --mist:#2D4F6C;
  --orange:#E87A2E;
  --brick:#B94E3B;
  --orange-soft:#F2A25C;
  --sand:#D8CBB8;
  --paper:#F4EFE6;
  --steel:#6E7F8F;

  --rail-w:240px;
  --bar-h:60px;
  --content-max:1140px;

  --font-display:"Noto Serif SC","Source Han Serif SC","Songti SC","SimSun",serif;
  --font-heading:"HarmonyOS Sans SC","Source Han Sans SC","PingFang SC","Microsoft YaHei",sans-serif;
  --font-body:"Noto Serif SC","Source Han Serif SC","Songti SC","SimSun",serif;
  --font-mono:"IBM Plex Mono","JetBrains Mono",ui-monospace,SFMono-Regular,Menlo,monospace;

  --ease:cubic-bezier(.22,.61,.36,1);
  --line:rgba(16,27,51,.14);
  --line-soft:rgba(216,203,184,.18);
  --shadow-note:0 18px 40px -24px rgba(10,16,32,.55);
}

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

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

body{
  margin:0;
  padding-left:var(--rail-w);
  background-color:var(--paper);
  background-image:radial-gradient(rgba(16,27,51,.045) 1px,transparent 1px);
  background-size:4px 4px;
  color:var(--ink);
  font-family:var(--font-body);
  font-size:16px;
  line-height:1.85;
  letter-spacing:.02em;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}

img,svg,video{max-width:100%;display:block;}
ul,ol{margin:0;padding:0;list-style:none;}
a{color:inherit;}
button{font:inherit;color:inherit;}
p{margin:0 0 1em;}
p:last-child{margin-bottom:0;}

a:focus-visible,
button:focus-visible,
[tabindex]:focus-visible{
  outline:2px solid var(--orange);
  outline-offset:3px;
}
.rail a:focus-visible,
.rail button:focus-visible,
.site-foot a:focus-visible,
.site-foot button:focus-visible{
  outline-color:var(--orange-soft);
}

h1,h2,h3,h4,h5{
  margin:0;
  color:var(--indigo);
  line-height:1.24;
  letter-spacing:.01em;
}
h1{
  font-family:var(--font-display);
  font-weight:700;
  font-size:clamp(30px,4.4vw,56px);
}
h2{
  font-family:var(--font-heading);
  font-weight:700;
  font-size:clamp(21px,2.6vw,32px);
}
h3{
  font-family:var(--font-heading);
  font-weight:600;
  font-size:clamp(17px,1.7vw,21px);
}
h4{
  font-family:var(--font-heading);
  font-weight:600;
  font-size:16px;
}

.sr-only{
  position:absolute;
  width:1px;height:1px;
  padding:0;margin:-1px;
  overflow:hidden;
  clip:rect(0 0 0 0);
  white-space:nowrap;
  border:0;
}

.skip-link{
  position:fixed;
  top:10px;
  left:10px;
  z-index:200;
  transform:translateY(-180%);
  background:var(--orange);
  color:#180D04;
  font-family:var(--font-heading);
  font-size:14px;
  font-weight:600;
  letter-spacing:.04em;
  padding:10px 18px;
  border-radius:2px;
  text-decoration:none;
  transition:transform .18s var(--ease);
}
.skip-link:focus{transform:none;}

/* ============ 纵向时间轴导航（头部） ============ */

.rail{
  position:fixed;
  inset:0 auto 0 0;
  width:var(--rail-w);
  display:flex;
  flex-direction:column;
  z-index:60;
  color:var(--paper);
  background:
    radial-gradient(120% 60% at 20% 0%,rgba(45,79,108,.55),transparent 62%),
    linear-gradient(180deg,#101B33 0%,#0C1528 48%,#16233C 100%);
  border-right:1px solid var(--line-soft);
  padding-bottom:18px;
}
.rail::after{
  content:"";
  position:absolute;
  top:0;
  right:-1px;
  bottom:0;
  width:1px;
  pointer-events:none;
  background-image:repeating-linear-gradient(180deg,rgba(216,203,184,.42) 0 1px,transparent 1px 13px);
}

.rail-top{
  display:flex;
  flex-direction:column;
  gap:10px;
  padding:26px 22px 20px;
  border-bottom:1px solid var(--line-soft);
}

.rail-status{
  display:flex;
  align-items:center;
  gap:8px;
  margin:0;
  font-family:var(--font-mono);
  font-size:10px;
  letter-spacing:.16em;
  color:rgba(242,162,92,.92);
}
.rail-status__dot{
  width:6px;height:6px;
  border-radius:50%;
  background:var(--orange);
  box-shadow:0 0 0 3px rgba(232,122,46,.18);
  flex:0 0 auto;
}
.rail-status__text{white-space:nowrap;}

.rail-brand__logo{
  display:block;
  text-decoration:none;
  color:var(--paper);
}
.rail-brand__glyph{
  display:block;
  font-family:var(--font-heading);
  font-weight:800;
  font-size:30px;
  line-height:1;
  letter-spacing:.18em;
  color:#fff;
}
.rail-brand__en{
  display:block;
  margin-top:7px;
  font-family:var(--font-mono);
  font-size:9px;
  letter-spacing:.34em;
  color:var(--orange-soft);
}
.rail-brand__line{
  margin:0;
  font-family:var(--font-body);
  font-size:12px;
  line-height:1.75;
  letter-spacing:.06em;
  color:rgba(244,239,230,.58);
}

.rail-toggle{
  display:none;
  align-items:center;
  gap:8px;
  padding:8px 12px;
  border:1px solid rgba(216,203,184,.3);
  border-radius:2px;
  background:rgba(244,239,230,.06);
  color:var(--paper);
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.16em;
  cursor:pointer;
  transition:background .18s var(--ease),border-color .18s var(--ease);
}
.rail-toggle:hover{background:rgba(232,122,46,.2);border-color:rgba(242,162,92,.6);}
.rail-toggle__bars{
  position:relative;
  display:block;
  width:16px;
  height:10px;
}
.rail-toggle__bars::before,
.rail-toggle__bars::after{
  content:"";
  position:absolute;
  left:0;
  width:16px;
  height:1.5px;
  background:var(--paper);
  transition:transform .2s var(--ease);
}
.rail-toggle__bars::before{top:0;}
.rail-toggle__bars::after{bottom:0;}
.rail[data-open="true"] .rail-toggle__bars::before{transform:translateY(4.25px) rotate(45deg);}
.rail[data-open="true"] .rail-toggle__bars::after{transform:translateY(-4.25px) rotate(-45deg);}
.rail-toggle__text{line-height:1;}

.rail-nav{
  flex:1 1 auto;
  overflow-y:auto;
  padding:14px 0;
  overscroll-behavior:contain;
}
.rail-nav__list{
  display:flex;
  flex-direction:column;
  gap:2px;
}
.rail-nav__item{position:relative;}
.rail-nav__link{
  display:grid;
  grid-template-columns:34px minmax(0,1fr);
  align-items:center;
  gap:10px;
  padding:12px 20px 12px 18px;
  text-decoration:none;
  color:rgba(244,239,230,.76);
  font-family:var(--font-heading);
  font-size:14px;
  font-weight:500;
  letter-spacing:.04em;
  line-height:1.4;
  border-left:2px solid transparent;
  transition:color .18s var(--ease),background .18s var(--ease),border-color .18s var(--ease);
}
.rail-nav__num{
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.08em;
  color:rgba(242,162,92,.55);
  transition:color .18s var(--ease);
}
.rail-nav__label{display:block;}
.rail-nav__link:hover,
.rail-nav__link:focus-visible{
  color:#fff;
  background:rgba(45,79,108,.42);
  border-left-color:var(--orange-soft);
}
.rail-nav__link:hover .rail-nav__num,
.rail-nav__link:focus-visible .rail-nav__num{color:var(--orange-soft);}
.rail-nav__link[aria-current="page"]{
  color:#fff;
  border-left-color:var(--orange);
  background:linear-gradient(90deg,rgba(232,122,46,.26),rgba(232,122,46,0));
}
.rail-nav__link[aria-current="page"] .rail-nav__num{color:var(--orange);}

.rail-actions{
  display:flex;
  flex-direction:column;
  gap:8px;
  padding:14px 22px 0;
  border-top:1px solid var(--line-soft);
}
.rail-actions .btn{width:100%;}

/* ============ 按钮体系 ============ */

.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:8px;
  padding:11px 20px;
  border:1px solid transparent;
  border-radius:2px;
  font-family:var(--font-heading);
  font-weight:600;
  font-size:14px;
  letter-spacing:.06em;
  line-height:1.4;
  text-decoration:none;
  cursor:pointer;
  transition:background .18s var(--ease),color .18s var(--ease),border-color .18s var(--ease),transform .18s var(--ease);
}
.btn--primary{
  background:var(--orange);
  color:#180D04;
}
.btn--primary:hover{background:var(--orange-soft);}
.btn--ghost{
  background:transparent;
  color:var(--paper);
  border-color:rgba(216,203,184,.34);
}
.btn--ghost:hover{
  background:rgba(244,239,230,.1);
  border-color:rgba(242,162,92,.72);
  color:#fff;
}

/* ============ 页脚 ============ */

.site-foot{
  position:relative;
  margin-top:clamp(48px,7vw,96px);
  padding:clamp(44px,6vw,80px) 0 26px;
  border-top:3px solid var(--brick);
  color:var(--paper);
  background:
    radial-gradient(120% 90% at 8% 0%,rgba(45,79,108,.6),transparent 62%),
    linear-gradient(180deg,#101B33 0%,#0E1830 58%,#0A1020 100%);
}
.site-foot::before{
  content:"";
  position:absolute;
  top:0;left:0;right:0;
  height:1px;
  background:linear-gradient(90deg,var(--orange),transparent 70%);
}
.foot-inner{
  width:min(100% - 48px,var(--content-max));
  margin-inline:auto;
}
.foot-grid{
  display:grid;
  grid-template-columns:minmax(0,1.15fr) minmax(0,1fr);
  gap:clamp(28px,4vw,64px);
  align-items:start;
}
.foot-brand__mark{
  margin:0 0 14px;
  font-family:var(--font-heading);
  font-weight:800;
  font-size:21px;
  letter-spacing:.16em;
  color:#fff;
}
.foot-brand__summary{
  max-width:34ch;
  margin:0 0 16px;
  font-size:15px;
  line-height:1.85;
  color:rgba(244,239,230,.74);
}
.foot-brand__meta{
  margin:0;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.12em;
  color:rgba(242,162,92,.86);
}
.foot-nav{
  display:grid;
  grid-template-columns:repeat(2,minmax(0,1fr));
  gap:24px;
}
.foot-nav__title{
  margin:0 0 14px;
  font-family:var(--font-mono);
  font-weight:500;
  font-size:10px;
  letter-spacing:.2em;
  color:var(--orange-soft);
}
.foot-nav__list{
  display:flex;
  flex-direction:column;
  gap:10px;
}
.foot-nav__list a{
  display:inline-block;
  font-family:var(--font-heading);
  font-size:14px;
  letter-spacing:.03em;
  color:rgba(244,239,230,.82);
  text-decoration:none;
  border-bottom:1px solid transparent;
  transition:color .18s var(--ease),border-color .18s var(--ease);
}
.foot-nav__list a:hover,
.foot-nav__list a:focus-visible{
  color:#fff;
  border-bottom-color:var(--orange);
}

.foot-contact{
  display:grid;
  grid-template-columns:repeat(auto-fit,minmax(210px,1fr));
  gap:18px 30px;
  margin-top:clamp(30px,4.5vw,52px);
  padding-top:26px;
  border-top:1px solid var(--line-soft);
}
.foot-contact__cell{
  display:flex;
  flex-direction:column;
  gap:6px;
  min-width:0;
}
.foot-contact__key{
  font-family:var(--font-mono);
  font-size:10px;
  letter-spacing:.18em;
  color:rgba(216,203,184,.72);
}
.foot-contact__val{
  font-family:var(--font-heading);
  font-size:13.5px;
  line-height:1.75;
  letter-spacing:.02em;
  color:rgba(244,239,230,.92);
  overflow-wrap:anywhere;
}

.foot-base{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  justify-content:space-between;
  gap:10px 24px;
  margin-top:clamp(24px,3.5vw,38px);
  padding-top:18px;
  border-top:1px solid var(--line-soft);
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.08em;
  color:rgba(244,239,230,.52);
}
.foot-base__copy,
.foot-base__icp{margin:0;}
.foot-base__legal{
  display:flex;
  flex-wrap:wrap;
  gap:18px;
}
.foot-base__legal a{
  color:rgba(244,239,230,.66);
  text-decoration:none;
  border-bottom:1px solid transparent;
  transition:color .18s var(--ease),border-color .18s var(--ease);
}
.foot-base__legal a:hover,
.foot-base__legal a:focus-visible{
  color:var(--orange-soft);
  border-bottom-color:var(--orange-soft);
}

/* ============ 正文容器与通用组件 ============ */

.wrap{
  width:min(100% - 48px,var(--content-max));
  margin-inline:auto;
}
.page{
  padding-block:clamp(26px,4vw,52px) 0;
}

.crumbs{
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.12em;
  color:var(--steel);
}
.crumbs ol{
  display:flex;
  flex-wrap:wrap;
  gap:8px;
}
.crumbs li{
  display:flex;
  align-items:center;
  gap:8px;
}
.crumbs li + li::before{
  content:"—";
  color:var(--sand);
}
.crumbs a{
  color:var(--mist);
  text-decoration:none;
  border-bottom:1px solid transparent;
  transition:border-color .18s var(--ease),color .18s var(--ease);
}
.crumbs a:hover,
.crumbs a:focus-visible{
  color:var(--indigo);
  border-bottom-color:currentColor;
}
.crumbs [aria-current="page"]{color:var(--brick);}

.section{
  padding-block:clamp(38px,6vw,84px);
}
.band{
  background:linear-gradient(120deg,rgba(216,203,184,.55),rgba(242,162,92,.14));
  border-block:1px solid var(--line);
}

.chapter{
  display:grid;
  grid-template-columns:auto minmax(0,1fr);
  gap:6px 18px;
  align-items:baseline;
}
.chapter__num{
  grid-row:span 2;
  font-family:var(--font-mono);
  font-weight:500;
  font-size:clamp(26px,4vw,46px);
  line-height:1;
  letter-spacing:.06em;
  color:var(--orange);
}
.chapter__title{
  font-family:var(--font-display);
  font-weight:700;
  font-size:clamp(21px,2.4vw,32px);
  color:var(--indigo);
}
.chapter__lead{
  margin:0;
  max-width:46ch;
  font-size:15px;
  line-height:1.8;
  color:var(--mist);
}

.lede{
  max-width:42ch;
  font-size:clamp(17px,1.6vw,20px);
  line-height:1.85;
  color:var(--indigo-2);
}

.grid{
  display:grid;
  gap:clamp(18px,2.4vw,28px);
}
.grid--2{grid-template-columns:repeat(2,minmax(0,1fr));}
.grid--3{grid-template-columns:repeat(3,minmax(0,1fr));}

.card{
  background:#FBF7F0;
  border:1px solid var(--line);
  border-radius:2px;
  padding:clamp(18px,2.4vw,28px);
}

.note{
  background:linear-gradient(160deg,#FBF6EC,#F0E6D6);
  border:1px solid rgba(16,27,51,.12);
  border-left:3px solid var(--orange-soft);
  border-radius:2px;
  padding:16px 18px;
  box-shadow:var(--shadow-note);
}

.tag{
  display:inline-flex;
  align-items:center;
  gap:6px;
  padding:4px 9px;
  border:1px solid rgba(185,78,59,.4);
  border-radius:2px;
  background:rgba(185,78,59,.07);
  font-family:var(--font-mono);
  font-size:10px;
  letter-spacing:.14em;
  line-height:1.5;
  color:var(--brick);
}

.num{
  font-family:var(--font-mono);
  letter-spacing:.08em;
}

.media{
  position:relative;
  overflow:hidden;
  aspect-ratio:4 / 3;
  border:1px solid var(--line);
  border-radius:2px;
  background:linear-gradient(150deg,var(--sand),#C6B49D 58%,#B6A48C);
}
.media > img{
  width:100%;
  height:100%;
  object-fit:cover;
}
.media--wide{aspect-ratio:16 / 9;}
.media--tall{aspect-ratio:3 / 4;}
.media--square{aspect-ratio:1 / 1;}
.media__cap{
  margin:10px 0 0;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.1em;
  color:var(--steel);
}

[data-reveal]{
  transition:opacity .22s var(--ease),transform .22s var(--ease);
}
[data-reveal].is-in{
  opacity:1;
  transform:none;
}

.read-progress{
  position:fixed;
  top:0;
  left:var(--rail-w);
  right:0;
  height:2px;
  z-index:80;
  pointer-events:none;
  background:linear-gradient(90deg,var(--orange),var(--brick));
  transform:scaleX(0);
  transform-origin:0 50%;
}

/* ============ 响应式：平板 88px 轨道 ============ */

@media (min-width:768px) and (max-width:1023px){
  :root{--rail-w:88px;}

  .rail-top{
    align-items:center;
    text-align:center;
    padding:18px 8px 14px;
    gap:8px;
  }
  .rail-status,
  .rail-brand__line,
  .rail-brand__en{display:none;}
  .rail-brand__glyph{
    font-size:20px;
    letter-spacing:.1em;
  }
  .rail-nav{padding:10px 0;}
  .rail-nav__link{
    grid-template-columns:minmax(0,1fr);
    justify-items:center;
    gap:5px;
    padding:9px 4px;
  }
  .rail-nav__num{font-size:9px;}
  .rail-nav__label{
    writing-mode:vertical-rl;
    font-size:11px;
    letter-spacing:.12em;
    line-height:1.45;
  }
  .rail-actions{display:none;}
}

/* ============ 响应式：移动端顶部窄条 + 抽屉 ============ */

@media (max-width:767px){
  :root{--rail-w:0px;}

  body{
    padding-left:0;
    padding-top:var(--bar-h);
  }

  .rail{
    inset:0 0 auto 0;
    width:100%;
    height:var(--bar-h);
    flex-direction:row;
    align-items:center;
    padding:0 16px;
    border-right:0;
    border-bottom:1px solid var(--line-soft);
  }
  .rail::after{display:none;}

  .rail-top{
    flex-direction:row;
    align-items:center;
    gap:12px;
    width:100%;
    padding:0;
    border-bottom:0;
  }
  .rail-status,
  .rail-brand__line{display:none;}
  .rail-brand__glyph{
    font-size:21px;
    letter-spacing:.14em;
  }
  .rail-brand__en{
    margin-top:3px;
    font-size:8px;
    letter-spacing:.26em;
  }
  .rail-toggle{
    display:inline-flex;
    margin-left:auto;
  }

  .rail-nav{
    position:fixed;
    top:var(--bar-h);
    right:0;
    bottom:0;
    left:0;
    z-index:65;
    padding:20px 18px 132px;
    background:linear-gradient(180deg,#0C1528 0%,#101B33 42%,#0A1020 100%);
    opacity:0;
    visibility:hidden;
    transform:translateY(-10px);
    transition:opacity .2s var(--ease),transform .2s var(--ease),visibility .2s var(--ease);
  }
  .rail[data-open="true"] .rail-nav{
    opacity:1;
    visibility:visible;
    transform:none;
  }
  .rail-nav__link{
    grid-template-columns:38px minmax(0,1fr);
    padding:14px 12px 14px 10px;
    font-size:16px;
  }
  .rail-nav__num{font-size:12px;}

  .rail-actions{
    position:fixed;
    right:18px;
    bottom:22px;
    left:18px;
    z-index:70;
    flex-direction:row;
    gap:10px;
    padding:0;
    border-top:0;
    opacity:0;
    visibility:hidden;
    transform:translateY(8px);
    transition:opacity .2s var(--ease),transform .2s var(--ease),visibility .2s var(--ease);
  }
  .rail[data-open="true"] .rail-actions{
    opacity:1;
    visibility:visible;
    transform:none;
  }
  .rail-actions .btn{
    flex:1 1 0;
    padding:12px 10px;
    font-size:13px;
  }

  .read-progress{
    left:0;
    top:var(--bar-h);
  }

  .wrap,
  .foot-inner{width:min(100% - 32px,var(--content-max));}

  .foot-grid{grid-template-columns:minmax(0,1fr);}
  .foot-nav{grid-template-columns:repeat(2,minmax(0,1fr));gap:20px;}
  .foot-base{justify-content:flex-start;}
  .grid--2,
  .grid--3{grid-template-columns:minmax(0,1fr);}
  .chapter{gap:4px 12px;}
  .rail-toggle__text{display:none;}
}

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