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

:root{
  --paper:#fdfbf7;
  --paper-2:#f5f5f5;
  --ink:#1a1a1a;
  --line:#e0e0e0;
  --r:10px;
  --max:1080px;
  --sans:"Rubik","Nunito Sans",system-ui,-apple-system,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  --serif:Georgia,"Songti SC","Noto Serif CJK SC","Source Han Serif SC","SimSun",serif;
}
*,*::before,*::after{box-sizing:border-box}
html{
  scroll-behavior:smooth;
  scroll-padding-bottom:130px;
  -webkit-text-size-adjust:100%;
}
body{
  margin:0;
  padding:0 0 118px;
  background:var(--paper);
  color:var(--ink);
  font-family:var(--sans);
  font-size:17px;
  line-height:1.75;
  letter-spacing:.01em;
  -webkit-font-smoothing:antialiased;
}
body::before{
  content:"";
  position:fixed;
  inset:0;
  z-index:1;
  pointer-events:none;
  opacity:.55;
  background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='140' height='140'%3E%3Cfilter id='g'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.85' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='140' height='140' filter='url(%23g)' opacity='.22'/%3E%3C/svg%3E");
}
img{max-width:100%}
a{color:var(--ink)}
:focus-visible{outline:2px solid var(--ink);outline-offset:3px}

.skip{
  position:absolute;
  left:-9999px;
  top:0;
  z-index:60;
  padding:.7rem 1rem;
  background:var(--ink);
  color:var(--paper);
  text-decoration:none;
}
.skip:focus{left:.8rem;top:.8rem}

/* 首屏 */
.hero{
  max-width:var(--max);
  margin:0 auto;
  padding:3rem 1.25rem 2rem;
  min-height:70vh;
  display:grid;
  align-content:center;
  justify-items:center;
  gap:1.2rem;
  text-align:center;
}
.hero h1{
  margin:0;
  font-size:clamp(2rem,6.2vw,3.4rem);
  line-height:1.18;
  font-weight:700;
  letter-spacing:-.025em;
  max-width:22em;
}
.lede{
  margin:0;
  max-width:32em;
  font-size:17px;
  line-height:1.9;
  color:#3d3d3d;
}
.hero-fig{
  margin:1.6rem 0 0;
  width:100%;
  max-width:740px;
  border:1px solid var(--line);
  border-radius:var(--r);
  overflow:hidden;
  background:var(--paper-2);
}
.hero-fig img{display:block;width:100%;height:auto}

/* 正文 + 右侧栏 */
.read{
  max-width:var(--max);
  margin:0 auto;
  padding:1.2rem 1.25rem 2.5rem;
  display:grid;
  grid-template-columns:minmax(0,1fr) 252px;
  gap:2.8rem;
  align-items:start;
}
.prose{
  min-width:0;
  font-family:var(--serif);
  font-size:17.5px;
  line-height:1.95;
  letter-spacing:.015em;
  overflow-wrap:break-word;
}
.prose section{
  scroll-margin-top:2rem;
  scroll-margin-bottom:130px;
}
.prose section + section{
  margin-top:3rem;
  padding-top:3rem;
  border-top:1px solid var(--line);
}
.prose > section:first-child{padding-top:0}
.prose :is(h2,h3,h4){
  font-family:var(--sans);
  line-height:1.35;
  letter-spacing:-.01em;
  margin:2rem 0 .8rem;
}
.prose h2{font-size:clamp(1.35rem,3.4vw,1.7rem);font-weight:600}
.prose h3{font-size:1.18rem;font-weight:600}
.prose p{margin:0 0 1.15rem}
.prose a{
  text-decoration:underline;
  text-decoration-thickness:1px;
  text-underline-offset:3px;
}
.prose ul,.prose ol{padding-left:1.35rem;margin:0 0 1.2rem}
.prose li{margin:.3rem 0}
.prose blockquote{
  margin:1.6rem 0;
  padding:.2rem 0 .2rem 1.1rem;
  border-left:3px solid var(--ink);
  color:#333;
}
.prose figure{margin:1.6rem 0}
.prose img{
  display:block;
  height:auto;
  border:1px solid var(--line);
  border-radius:var(--r);
}
.prose figcaption{
  margin-top:.55rem;
  font-family:var(--sans);
  font-size:15px;
  color:#6a6a6a;
}
.prose table{width:100%;border-collapse:collapse;margin:1.4rem 0;font-size:16px}
.prose th,.prose td{border:1px solid var(--line);padding:.55rem .7rem;text-align:left}
.prose code{
  font-family:ui-monospace,"SFMono-Regular",Menlo,Consolas,monospace;
  font-size:.92em;
  border:1px solid var(--line);
  border-radius:4px;
  padding:.05em .3em;
}
.prose hr{border:0;border-top:1px solid var(--line);margin:2rem 0}

/* 侧栏 */
.side{
  position:sticky;
  top:1.25rem;
  padding:1.1rem 1rem 1.2rem;
  border:1px solid var(--line);
  border-radius:var(--r);
  background:var(--paper-2);
}
.side small{
  display:block;
  font-size:15px;
  line-height:1.4;
  letter-spacing:.22em;
  color:#6a6a6a;
}
.side h2{
  margin:.15rem 0 .85rem;
  font-size:20px;
  font-weight:600;
  letter-spacing:.02em;
  line-height:1.4;
}
.side ol{list-style:none;margin:0;padding:0;display:grid;gap:.1rem}
.side a{
  display:flex;
  align-items:center;
  min-height:42px;
  padding:.3rem .1rem;
  font-size:16px;
  line-height:1.4;
  text-decoration:none;
  border-bottom:1px solid transparent;
}
.side a:hover,.side a:focus-visible{border-bottom-color:var(--ink)}

/* 页脚 */
.foot{
  margin-top:3.5rem;
  border-top:1px solid var(--ink);
}
.foot-in{
  max-width:var(--max);
  margin:0 auto;
  padding:2.2rem 1.25rem 2.4rem;
}
.foot-word{
  margin:0 0 1.4rem;
  font-size:clamp(2.4rem,12.5vw,5.2rem);
  line-height:.95;
  font-weight:700;
  letter-spacing:-.045em;
}
.foot-word a{text-decoration:none}
.foot-mid{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  justify-content:space-between;
  gap:.8rem 1.4rem;
  padding-top:1rem;
  border-top:1px solid var(--line);
}
.foot address{
  font-style:normal;
  font-size:16px;
  letter-spacing:.06em;
}
.foot ul{
  display:flex;
  flex-wrap:wrap;
  gap:.2rem 1.1rem;
  list-style:none;
  margin:0;
  padding:0;
}
.foot ul a{
  display:inline-flex;
  align-items:center;
  min-height:42px;
  font-size:16px;
  text-decoration:none;
  border-bottom:1px solid var(--line);
}
.foot ul a:hover,.foot ul a:focus-visible{border-bottom-color:var(--ink)}
.foot-copy{
  margin:1.5rem 0 0;
  text-align:center;
  font-size:16px;
  letter-spacing:.1em;
  color:#5e5e5e;
}

/* 底部胶囊栏 */
.dock{
  position:fixed;
  left:0;
  right:0;
  bottom:0;
  z-index:30;
  display:flex;
  align-items:center;
  gap:.55rem;
  padding:.55rem .7rem calc(.55rem + env(safe-area-inset-bottom));
  padding-left:max(.7rem, calc((100vw - 1120px) / 2));
  padding-right:max(.7rem, calc((100vw - 1120px) / 2));
  background:rgba(253,251,247,.97);
  border-top:1px solid var(--ink);
}
.dock-mark{
  flex:0 0 auto;
  display:inline-flex;
  align-items:center;
  justify-content:center;
  width:44px;
  height:44px;
  border:1px solid var(--ink);
  border-radius:999px;
  background:var(--ink);
  color:var(--paper);
  font-size:17px;
  font-weight:600;
  letter-spacing:-.03em;
  text-decoration:none;
  overflow:hidden;
}
.dock-mark img{display:block;width:26px;height:26px;object-fit:contain}
.dock-nav{
  flex:1 1 auto;
  min-width:0;
  overflow-x:auto;
  scrollbar-width:none;
}
.dock-nav::-webkit-scrollbar{display:none}
.dock-nav ol{display:flex;gap:.4rem;margin:0;padding:0;list-style:none}
.dock-nav li{flex:0 0 auto}
.dock-nav a{
  display:inline-flex;
  align-items:center;
  min-height:44px;
  padding:.45rem 1rem;
  border:1px solid var(--line);
  border-radius:999px;
  background:var(--paper);
  font-size:16px;
  line-height:1.2;
  white-space:nowrap;
  text-decoration:none;
}
.dock-nav a:hover,.dock-nav a:focus-visible{
  background:var(--ink);
  border-color:var(--ink);
  color:var(--paper);
}

/* 瞬时出现 */
html.js .prose article{opacity:0}
html.js .prose article.in{opacity:1}

@media (max-width:860px){
  .read{grid-template-columns:1fr;gap:1.6rem}
  .side{position:static;order:-1}
  .hero{min-height:62vh;padding-top:2.2rem}
}
@media (max-width:520px){
  body{font-size:16.5px;padding-bottom:110px}
  .prose{font-size:17px;line-height:1.9}
  .dock{padding-left:.6rem;padding-right:.6rem;gap:.45rem}
  .dock-nav a{padding:.4rem .85rem;font-size:15.5px}
  .foot-in{padding-bottom:2rem}
}
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
}

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