html{scroll-behavior:smooth}
:root{
  --paper:#f5e6c8;
  --paper-2:#eeddb7;
  --paper-3:#fbf4e2;
  --accent:#d4a574;
  --ink:#262117;
  --ink-2:#4a3f2f;
  --line:rgba(38,33,23,.3);
  --line-soft:rgba(38,33,23,.16);
  --radius:4px;
  --rail:140px;
}
*,*::before,*::after{box-sizing:border-box}
body{
  margin:0;
  background:var(--paper);
  color:var(--ink);
  font-family:'Atkinson Hyperlegible','Helvetica Neue',Arial,'PingFang SC','Hiragino Sans GB','Microsoft YaHei',sans-serif;
  font-size:1.0625rem;
  line-height:1.72;
  overflow-x:hidden;
  -webkit-font-smoothing:antialiased;
}
img{max-width:100%;height:auto}
a{color:var(--ink);text-decoration-thickness:1px;text-underline-offset:3px}
a:hover{color:#7a5a2e}
:focus-visible{outline:3px solid var(--accent);outline-offset:3px;border-radius:2px}
::selection{background:var(--accent);color:var(--ink)}

/* —— 胶片颗粒 & 漏光 —— */
.grain{
  position:fixed;inset:0;z-index:60;pointer-events:none;opacity:.2;mix-blend-mode:multiply;
  background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='150' height='150'%3E%3Cfilter id='g'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.82' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='150' height='150' filter='url(%23g)' opacity='0.55'/%3E%3C/svg%3E");
}
.leak{
  position:fixed;inset:0;z-index:55;pointer-events:none;opacity:.55;
  background:
    radial-gradient(46% 32% at 92% 3%,rgba(212,165,116,.6),transparent 72%),
    radial-gradient(34% 40% at 2% 98%,rgba(251,244,226,.75),transparent 70%);
  animation:leakDrift 16s ease-in-out infinite alternate;
}
@keyframes leakDrift{
  from{opacity:.35;transform:translate3d(0,0,0)}
  to{opacity:.7;transform:translate3d(-1.2%,1%,0)}
}

/* —— 左侧固定竖排导航 —— */
.rail{
  position:fixed;left:0;top:0;bottom:0;width:var(--rail);z-index:40;
  display:flex;flex-direction:column;gap:14px;
  padding:16px 10px 18px;
  border-right:1px solid var(--line);
  background:linear-gradient(180deg,#efdfba 0%,var(--paper) 46%,#f2e3c1 100%);
  overflow-y:auto;
}
.brandmark{
  display:inline-flex;align-items:center;justify-content:center;
  width:44px;height:44px;flex:0 0 auto;
  border:1px solid var(--ink);border-radius:var(--radius);
  background:var(--ink);color:var(--paper);
  text-decoration:none;font-weight:700;letter-spacing:.06em;
  box-shadow:3px 3px 0 rgba(38,33,23,.28);
  transition:transform .18s ease;
}
.brandmark:hover{transform:translate(-1px,-1px) rotate(-2deg);color:var(--paper)}
.mark-img{display:block;width:100%;height:100%;object-fit:cover;border-radius:2px;filter:sepia(.35) contrast(1.05)}
.mark-txt{font-size:1.15rem;line-height:1}
.rail-nav ul{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:8px}
.rail-nav a{
  display:flex;align-items:center;justify-content:center;
  min-height:44px;padding:9px 10px;
  font-size:1rem;line-height:1.25;text-align:center;text-decoration:none;
  color:var(--ink);border:1px solid var(--line);border-radius:999px;
  background:rgba(251,244,226,.5);
  transition:background .18s ease,color .18s ease,transform .18s ease;
}
.rail-nav a:hover,.rail-nav a.on{
  background:var(--ink);color:var(--paper);border-color:var(--ink);
  transform:translateY(-1px);
}
.rail-contact{
  margin-top:auto;display:flex;align-items:center;justify-content:center;
  min-height:44px;padding:8px 10px;
  font-size:1rem;text-decoration:none;letter-spacing:.18em;
  border:1px dashed var(--ink);border-radius:999px;background:var(--accent);
  transition:background .18s ease;
}
.rail-contact:hover{background:var(--paper-3)}

/* —— 主体骨架 —— */
main{margin-left:var(--rail)}
.wrap{max-width:1120px;margin:0 auto;padding:0 28px}

/* —— 首屏 —— */
.hero{
  position:relative;overflow:hidden;
  display:grid;grid-template-columns:1.15fr .85fr;gap:36px;align-items:center;
  min-height:45vh;padding:46px 6px 40px;text-align:center;
  border-bottom:1px solid var(--line);
  background-image:radial-gradient(rgba(38,33,23,.14) 1px,transparent 1px);
  background-size:18px 18px;
}
.hero-copy{position:relative;z-index:2}
.hero h1{
  margin:0 0 14px;font-size:clamp(1.9rem,4.2vw,2.85rem);line-height:1.16;
  letter-spacing:.035em;text-wrap:balance;
}
.lede{
  max-width:36ch;margin:0 auto 22px;color:var(--ink-2);
  font-size:1.05rem;line-height:1.75;
}
.hero-cta{margin:0}
.hero-cta a{
  display:inline-flex;align-items:center;min-height:44px;padding:10px 24px;
  background:var(--ink);color:var(--paper);text-decoration:none;
  border-radius:999px;letter-spacing:.1em;font-size:1rem;
  box-shadow:4px 4px 0 rgba(212,165,116,.85);
  transition:transform .18s ease,box-shadow .18s ease;
}
.hero-cta a:hover{transform:translate(-1px,-1px);box-shadow:6px 6px 0 rgba(212,165,116,.9);color:var(--paper)}
.tracking{
  position:absolute;left:0;right:0;top:12%;height:26px;z-index:1;pointer-events:none;
  background:repeating-linear-gradient(180deg,rgba(38,33,23,.09) 0 1px,transparent 1px 4px);
  animation:vhs 7s steps(24) infinite;
}
@keyframes vhs{
  0%,100%{transform:translateY(0) skewX(0)}
  46%{transform:translateY(0) skewX(0)}
  48%{transform:translateY(-3px) skewX(-.6deg)}
  50%{transform:translateY(2px) skewX(.5deg)}
  52%{transform:translateY(0) skewX(0)}
}

/* —— 拍立得相框 —— */
.polaroid{
  position:relative;z-index:2;margin:0;
  padding:10px 10px 14px;border-radius:var(--radius);
  background:var(--paper-3);border:1px solid var(--line);
  transform:rotate(-1.8deg);
  transition:transform .3s ease;
}
.polaroid:hover{transform:rotate(.6deg) translateY(-3px)}
.hero-img{
  display:block;width:100%;aspect-ratio:4/5;object-fit:cover;border-radius:2px;
  filter:sepia(.34) contrast(1.06) saturate(.82);
}
.polaroid-blank{
  width:100%;aspect-ratio:4/5;border-radius:2px;
  background:
    repeating-linear-gradient(135deg,rgba(38,33,23,.07) 0 6px,transparent 6px 12px),
    linear-gradient(160deg,var(--accent),var(--paper-2));
}
.polaroid-tape{
  position:absolute;top:-11px;left:50%;width:74px;height:20px;
  transform:translateX(-50%) rotate(-3deg);
  background:rgba(212,165,116,.65);border:1px solid rgba(38,33,23,.18);
}

/* —— 正文区 + 右侧 aside —— */
.stage{
  display:grid;grid-template-columns:minmax(0,1fr) 280px;gap:46px;
  padding:8px 0 64px;align-items:start;
}
.sheet{min-width:0}
.sheet > section{
  padding:34px 0 30px;border-bottom:1px dashed var(--line-soft);
  scroll-margin-top:22px;
}
.sheet > section:first-child{padding-top:26px}
.sheet > section:last-child{border-bottom:0}
.sheet h2{
  margin:0 0 8px;font-size:clamp(1.35rem,2.4vw,1.7rem);line-height:1.3;
  letter-spacing:.03em;
}
.sheet h3{margin:26px 0 8px;font-size:1.15rem;letter-spacing:.02em}
.sheet h2 + hr,.sheet h3 + hr{
  width:76px;height:0;margin:0 0 18px;border:0;border-top:2px solid var(--accent);
}
.sheet p{margin:0 0 16px;max-width:66ch}
.sheet ul,.sheet ol{margin:0 0 18px;padding-left:1.4em;max-width:66ch}
.sheet li{margin:0 0 8px}
.sheet li::marker{color:#8a6a3d}
.sheet strong{background:linear-gradient(transparent 62%,rgba(212,165,116,.75) 62%)}
.sheet blockquote{
  margin:0 0 18px;padding:14px 18px;border-left:3px solid var(--accent);
  background:rgba(251,244,226,.6);border-radius:0 var(--radius) var(--radius) 0;
}
.sheet img{border-radius:var(--radius);filter:sepia(.28) contrast(1.05) saturate(.86)}

.side{
  position:sticky;top:24px;
  padding:18px 16px 20px;
  border:1px solid var(--line);border-radius:var(--radius);
  background:rgba(251,244,226,.62);
}
.side h2{margin:0 0 8px;font-size:1.1rem;letter-spacing:.14em}
.side hr{width:56px;height:0;margin:0 0 12px;border:0;border-top:2px solid var(--ink)}
.side-list{list-style:none;margin:0;padding:0}
.side-list a{
  display:block;min-height:40px;padding:9px 0;font-size:1rem;
  text-decoration:none;border-bottom:1px dotted var(--line);
}
.side-list a:hover,.side-list a.on{color:#7a5a2e}
.side-list a.on{font-weight:700}
.side-shot{margin-top:16px}
.side-shot img{
  display:block;width:100%;aspect-ratio:1/1;object-fit:cover;border-radius:2px;
  border:6px solid var(--paper-3);filter:sepia(.4) contrast(1.05) saturate(.8);
}

/* —— 页脚 —— */
.foot{
  margin-left:var(--rail);
  display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:14px;
  padding:34px 28px 40px;border-top:2px solid var(--ink);
  background:var(--paper-2);
}
.foot .cta{margin:0}
.foot .cta a{
  display:inline-flex;align-items:center;min-height:48px;padding:12px 30px;
  font-size:1.35rem;letter-spacing:.14em;text-decoration:none;
  background:var(--ink);color:var(--paper);border-radius:999px;
  transition:transform .18s ease;
}
.foot .cta a:hover{transform:translateY(-2px);color:var(--paper)}
.foot small{font-size:1rem;color:var(--ink-2);letter-spacing:.04em}

/* —— 滚动显现 —— */
.js .reveal{opacity:0;transform:translateY(14px);transition:opacity .6s ease,transform .6s ease}
.js .reveal.is-in{opacity:1;transform:none}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .leak,.tracking{animation:none}
  .js .reveal{opacity:1;transform:none;transition:none}
  .polaroid,.brandmark,.hero-cta a,.rail-nav a{transition:none}
}

/* —— 移动端 —— */
@media (max-width:900px){
  .rail{
    position:sticky;top:0;left:auto;right:auto;bottom:auto;
    width:auto;height:auto;flex-direction:row;align-items:center;gap:10px;
    padding:8px 12px;border-right:0;border-bottom:1px solid var(--line);
    overflow-x:auto;overflow-y:visible;
  }
  .rail-nav{flex:1 1 auto;min-width:0;overflow-x:auto;-webkit-overflow-scrolling:touch}
  .rail-nav ul{flex-direction:row;gap:8px}
  .rail-nav a{white-space:nowrap;min-height:44px;padding:9px 14px}
  .rail-contact{margin-top:0;min-height:44px;letter-spacing:.1em;padding:8px 14px;white-space:nowrap}
  main,.foot{margin-left:0}
  .wrap{padding:0 18px}
  .hero{grid-template-columns:1fr;gap:24px;min-height:0;padding:28px 4px 30px}
  .hero h1{font-size:clamp(1.75rem,7.4vw,2.2rem)}
  .lede{max-width:44ch}
  .hero-img,.polaroid-blank{aspect-ratio:16/11}
  .stage{grid-template-columns:1fr;gap:30px}
  .sheet > section{scroll-margin-top:76px}
  .side{position:static;order:2}
  .foot{padding:28px 18px 34px}
  .foot .cta a{font-size:1.2rem;padding:11px 24px}
}
@media (max-width:420px){
  .hero h1{letter-spacing:.02em}
  .brandmark{width:40px;height:40px}
}

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