/* 第一步：延续 Islong 的出版物气质，用留白和细线排版长文本。 */
:root { --paper:#f5f1e9; --ink:#192d36; --muted:#596973; --blue:#6685a2; --line:#cbd1cf; }
* { box-sizing:border-box; }
html { scroll-behavior:smooth; }
body { margin:0; background:var(--paper); color:var(--ink); font-family:Arial,Helvetica,sans-serif; }
a { color:inherit; }
a:focus-visible { outline:3px solid var(--blue); outline-offset:4px; }
.skip { position:absolute; left:-9999px; top:0; z-index:5; padding:10px; background:white; }
.skip:focus { left:10px; }
.shell { width:min(1160px,calc(100% - 70px)); margin:auto; }
.small { font-size:11px; font-weight:700; letter-spacing:.17em; text-transform:uppercase; }
.top { display:flex; align-items:center; justify-content:space-between; gap:25px; min-height:89px; border-bottom:1px solid var(--ink); }
.wordmark { font:26px Georgia,serif; letter-spacing:-.06em; text-decoration:none; white-space:nowrap; }
.wordmark span { display:inline-block; width:8px; height:8px; margin:0 6px 3px; border-radius:50%; background:var(--blue); }
.top nav { display:flex; flex-wrap:wrap; gap:28px; }
.top nav a { text-decoration:none; }
.top nav a:hover,.bottom a:hover { color:var(--blue); }
.intro { padding:135px 0 110px; border-bottom:1px solid var(--ink); }
.intro .small { color:var(--blue); }
.intro h1 { max-width:1000px; margin:27px 0 27px; font:400 clamp(72px,9vw,138px)/.88 Georgia,serif; letter-spacing:-.08em; }
.intro p:last-child { max-width:680px; margin:0; color:var(--muted); font-size:18px; line-height:1.7; }

/* 第二步：章节编号单独成栏，正文限制行宽以便逐段阅读。 */
.document { max-width:940px; margin:0 auto; padding:35px 0 120px; }
.meta { display:flex; justify-content:space-between; gap:20px; padding:20px 0 35px; color:var(--muted); }
.document section { display:grid; grid-template-columns:125px minmax(0,1fr); gap:40px; padding:48px 0; border-top:1px solid var(--line); }
.number { color:var(--blue); font:italic 32px Georgia,serif; }
.document h2 { margin:0 0 20px; font:400 clamp(33px,3.5vw,50px)/1.08 Georgia,serif; letter-spacing:-.045em; }
.document p,.document li { max-width:720px; color:var(--muted); font-size:16px; line-height:1.8; }
.document p { margin:0 0 16px; }
.document p:last-child { margin-bottom:0; }
.document ul { margin:0; padding-left:20px; }
.document a { color:#426c8d; text-underline-offset:3px; overflow-wrap:anywhere; }
.bottom { display:flex; flex-wrap:wrap; justify-content:space-between; gap:20px; padding:29px 0; border-top:1px solid var(--ink); color:var(--muted); }
.bottom a { text-decoration:none; }
@media(max-width:650px) {
  .shell { width:calc(100% - 36px); }
  .top { align-items:flex-start; flex-direction:column; padding:17px 0; }
  .top nav { gap:17px; }
  .top nav a { font-size:10px; }
  .intro { padding:83px 0 70px; }
  .intro h1 { font-size:clamp(46px,12vw,68px); overflow-wrap:anywhere; }
  .document { padding-bottom:75px; }
  .meta { flex-direction:column; gap:7px; }
  .document section { grid-template-columns:1fr; gap:10px; padding:36px 0; }
}