@import url('https://fonts.googleapis.com/css2?family=Exo+2:wght@300;400;500;600;700&family=Orbitron:wght@400;500;600;700&display=swap');

:root{
  --paper:#fdfbf7;
  --stone:#f5f5f5;
  --ink:#1a1a1a;
  --line:#e3dfd6;
  --hair:#eae6dd;
  --mid:#55514a;
  --sans:'Exo 2',system-ui,-apple-system,'PingFang SC','Microsoft YaHei',sans-serif;
  --disp:'Orbitron','Exo 2',system-ui,'PingFang SC',sans-serif;
  --serif:Georgia,'Songti SC','Noto Serif SC','Source Han Serif SC',serif;
}

*{box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{
  margin:0;
  background:var(--paper);
  color:var(--ink);
  font-family:var(--serif);
  font-size:17px;
  line-height:1.8;
  overflow-x:hidden;
}
body::before{
  content:"";
  position:fixed;
  inset:0;
  z-index:60;
  pointer-events:none;
  opacity:.05;
  background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='140' height='140'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='140' height='140' filter='url(%23n)'/%3E%3C/svg%3E");
}

a{color:inherit;text-decoration:none}
main{display:block}

.sr{
  position:absolute;
  width:1px;height:1px;
  overflow:hidden;
  clip-path:inset(50%);
  white-space:nowrap;
}

/* 顶部两行：品牌独占一行，菜单行在下 */
.mast{
  position:sticky;
  top:0;
  z-index:30;
  background:var(--paper);
  border-bottom:1px solid var(--line);
}
.mast > *{
  max-width:74rem;
  margin:0 auto;
  padding-left:clamp(1rem,4vw,3rem);
  padding-right:clamp(1rem,4vw,3rem);
}
.brandbar{
  display:flex;
  align-items:baseline;
  gap:1rem;
  padding-top:.8rem;
}
.brand{
  font-family:var(--disp);
  font-weight:700;
  font-size:1.02rem;
  letter-spacing:.15em;
  padding:.35rem 0;
  line-height:1.4;
}
.brand:hover{border-bottom:2px solid var(--ink)}

.menubar{
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:1rem;
  padding-bottom:.5rem;
}

nav ol{
  display:flex;
  gap:.1rem;
  list-style:none;
  margin:0;
  padding:0;
  overflow-x:auto;
  scrollbar-width:none;
}
nav ol::-webkit-scrollbar{display:none}
nav ol li{position:relative;flex:0 0 auto}
nav ol li > a{
  display:flex;
  align-items:center;
  min-height:44px;
  padding:.3rem .6rem;
  font-family:var(--sans);
  font-size:.92rem;
  font-weight:500;
  letter-spacing:.02em;
  white-space:nowrap;
  border-bottom:2px solid transparent;
}
nav ol li > a:hover,
nav ol li > a:focus-visible{border-bottom-color:var(--ink)}

.sub{
  position:absolute;
  top:100%;
  left:0;
  min-width:12rem;
  margin:.15rem 0 0;
  padding:.4rem;
  list-style:none;
  background:var(--stone);
  border-radius:18px;
  display:none;
  z-index:40;
}
.has-sub:hover .sub,
.has-sub:focus-within .sub{display:block}
.sub li a{
  display:flex;
  align-items:center;
  min-height:40px;
  padding:.3rem .7rem;
  font-family:var(--sans);
  font-size:.88rem;
  border-radius:12px;
}
.sub li a:hover{background:var(--paper)}

.search{display:flex;align-items:center;gap:.4rem}
.search input{
  font-family:var(--sans);
  font-size:16px;
  min-height:44px;
  width:9.5rem;
  padding:.4rem .9rem;
  border:1px solid var(--line);
  border-radius:999px;
  background:var(--paper);
  color:var(--ink);
}
.search input:focus{outline:2px solid var(--ink);outline-offset:1px}
.search button{
  font-family:var(--sans);
  font-size:.9rem;
  min-height:44px;
  padding:.4rem 1.1rem;
  border:0;
  border-radius:999px;
  background:var(--ink);
  color:var(--paper);
  cursor:pointer;
}

/* 版心：左侧索引栏 + 右侧正文 */
.sheet{
  display:grid;
  grid-template-columns:15rem minmax(0,1fr);
  gap:0 clamp(1.4rem,3vw,3rem);
  max-width:74rem;
  margin:0 auto;
  padding:0 clamp(1rem,4vw,3rem) 3rem;
}
.sheet > *{grid-column:2;min-width:0}
.sheet > .hero{grid-column:1 / -1;grid-row:1}
.sheet > aside{
  grid-column:1;
  grid-row:2 / span 80;
  align-self:start;
  position:sticky;
  top:7.6rem;
  max-height:calc(100vh - 9rem);
  overflow:auto;
}

/* 首屏 */
.hero{
  position:relative;
  overflow:hidden;
  display:grid;
  grid-template-columns:minmax(0,1fr) minmax(0,1.1fr);
  gap:1.4rem;
  align-items:end;
  min-height:45vh;
  padding:1.4rem 0 1.8rem;
}
.ghost{
  position:absolute;
  top:-.6rem;
  right:0;
  z-index:0;
  font-family:var(--disp);
  font-weight:700;
  font-size:clamp(5rem,18vw,13rem);
  line-height:.8;
  letter-spacing:-.02em;
  color:rgba(26,26,26,.07);
  pointer-events:none;
  user-select:none;
}
.collage{
  position:relative;
  height:clamp(190px,42vh,340px);
  z-index:1;
}
.shot{
  position:absolute;
  margin:0;
  overflow:hidden;
  border-radius:18px;
  background:var(--stone);
  z-index:1;
}
.shot.a{left:0;top:0;width:58%;height:76%;transform:rotate(-1.6deg)}
.shot.b{right:0;bottom:0;width:46%;height:58%;transform:rotate(1.6deg);z-index:2}
.shot:hover{transform:rotate(0)}
.shot img{width:100%;height:100%;object-fit:cover;display:block}
.ph{display:block;width:100%;height:100%;background:var(--stone)}

.hero-copy{
  position:relative;
  z-index:2;
  text-align:right;
}
.hero-copy h1{
  margin:0;
  font-family:var(--disp);
  font-weight:700;
  font-size:clamp(1.7rem,4.4vw,3.1rem);
  line-height:1.2;
  letter-spacing:.01em;
}

/* 正文段落区 */
div > section{
  padding:2rem 0;
  border-top:1px solid var(--line);
  scroll-margin-top:8.5rem;
}
div > section:last-child{padding-bottom:.5rem}

.sheet small{
  display:block;
  font-family:var(--sans);
  font-size:.72rem;
  font-weight:500;
  letter-spacing:.24em;
  color:var(--mid);
  margin-bottom:.3rem;
}
.sheet h2{
  font-family:var(--disp);
  font-weight:600;
  font-size:clamp(1.32rem,2.8vw,1.85rem);
  line-height:1.4;
  margin:0 0 .75rem;
}
.sheet h3{
  font-family:var(--disp);
  font-weight:600;
  font-size:1.08rem;
  line-height:1.55;
  margin:1.7rem 0 .5rem;
}
.sheet p{margin:0 0 1.15em}
.sheet p:last-child{margin-bottom:0}
.sheet ul,
.sheet ol{padding-left:1.35rem;margin:0 0 1.15em}
.sheet li{margin:.3rem 0}
.sheet a{text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px}
.sheet img{max-width:100%;height:auto;display:block;border-radius:18px;margin:1.2rem 0}
.sheet blockquote{
  margin:1.4rem 0;
  padding:1rem 1.2rem;
  background:var(--stone);
  border-radius:18px;
}
.sheet table{width:100%;border-collapse:collapse;margin:1.2rem 0;font-size:.94rem}
.sheet th,
.sheet td{border-bottom:1px solid var(--line);padding:.5rem .4rem;text-align:left}
.sheet pre{
  overflow-x:auto;
  background:var(--stone);
  padding:1rem;
  border-radius:18px;
  font-size:.86rem;
  line-height:1.6;
}

/* 左侧索引卡 */
.rail{
  background:var(--stone);
  border-radius:18px;
  padding:1.1rem 1rem;
}
.rail h2{
  font-family:var(--disp);
  font-size:1.02rem;
  font-weight:600;
  margin:0 0 .55rem;
  line-height:1.4;
}
.rail ol{list-style:none;margin:0;padding:0}
.rail li a{
  display:flex;
  align-items:center;
  min-height:40px;
  padding:.35rem .1rem;
  font-family:var(--sans);
  font-size:.87rem;
  line-height:1.45;
  color:#37342e;
  border-bottom:1px solid var(--hair);
}
.rail li:last-child a{border-bottom:0}
.rail li a:hover{color:#000;text-decoration:underline;text-underline-offset:4px}

/* 页脚 */
footer{
  max-width:74rem;
  margin:0 auto;
  padding:2.4rem clamp(1rem,4vw,3rem) 1.6rem;
  border-top:1px solid var(--line);
}
.wordmark{
  margin:0;
  font-family:var(--disp);
  font-weight:700;
  font-size:clamp(1.9rem,9.5vw,5.6rem);
  line-height:1.02;
  letter-spacing:.03em;
  word-break:break-word;
}
.foot-line{
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:1rem;
  margin-top:1.4rem;
  padding-top:1rem;
  border-top:1px solid var(--line);
  font-family:var(--sans);
}
.copy{margin:0;font-size:.84rem;color:var(--mid)}
.totop{
  display:inline-flex;
  align-items:center;
  min-height:44px;
  padding:.45rem 1.1rem;
  border:1px solid var(--ink);
  border-radius:999px;
  font-size:.88rem;
}
.totop:hover{background:var(--ink);color:var(--paper)}

/* 动效：短促位移，无渐变过渡 */
@keyframes rise{
  from{transform:translateY(12px);opacity:.001}
  to{transform:none;opacity:1}
}
.collage,
.hero-copy{animation:rise .26s ease-out both}
div > section.in{animation:rise .24s ease-out both;animation-delay:calc(var(--i,0) * 45ms)}

@media (max-width:780px){
  .menubar{flex-direction:column;align-items:stretch;gap:.5rem}
  .search{width:100%}
  .search input{flex:1 1 auto;width:auto}
  .sub{display:none}
  .sheet{grid-template-columns:minmax(0,1fr)}
  .sheet > *,
  .sheet > .hero,
  .sheet > aside{grid-column:1}
  .sheet > .hero{grid-row:auto}
  .sheet > aside{
    grid-row:auto;
    position:static;
    max-height:none;
    margin:.4rem 0 1.4rem;
  }
  .hero{
    grid-template-columns:minmax(0,1fr);
    min-height:0;
    padding-top:1rem;
  }
  .collage{height:168px}
  .hero-copy{margin-top:.7rem;text-align:right}
  div > section{scroll-margin-top:9.5rem}
}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .collage,
  .hero-copy,
  div > section.in{animation:none}
}

button[aria-expanded]{min-width:44px;min-height:44px}