:root{
  --bg:#f5f7fa; --ink:#22323d; --ink-soft:#3c5566; --ink-faint:#7a8a96;
  --navy:#0f2b3d; --accent:#145a80; --line:#dde5ec; --card:#ffffff; --soft:#eef3f7;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}}
html,body{margin:0;padding:0}
body{
  background:var(--bg);color:var(--ink);
  font-family:-apple-system,"PingFang SC","Hiragino Sans GB","Microsoft YaHei","Noto Sans SC",sans-serif;
  line-height:1.85;font-size:16.5px;
}
a{color:var(--accent);text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px}
a:hover{color:var(--navy)}
a:focus-visible{outline:2px solid var(--accent);outline-offset:2px;border-radius:3px}
header.site{
  display:flex;align-items:center;justify-content:space-between;gap:12px;
  padding:20px 30px;border-bottom:1px solid var(--line);background:var(--card);
}
.brand{display:flex;align-items:center;gap:10px;color:var(--navy);text-decoration:none}
.brand svg{display:block}
.brand .word{font-family:Georgia,"Times New Roman",serif;font-size:19px;letter-spacing:.04em}
nav.top a{font-size:14.5px;color:var(--ink-soft);text-decoration:none;margin-left:18px}
nav.top a:hover{color:var(--navy);text-decoration:underline;text-underline-offset:3px}
nav.top a:focus-visible{outline:2px solid var(--accent);outline-offset:2px;border-radius:3px}
@media (max-width:560px){
  nav.top a{font-size:13px;margin-left:12px}
}
main{max-width:720px;margin:0 auto;padding:44px 24px 64px}
main.home{max-width:1160px}
@media (min-width:820px){
  .cardlist{grid-template-columns:repeat(2,1fr)}
}
@media (min-width:1200px){
  main.home .cardlist{grid-template-columns:repeat(3,1fr)}
}
footer.site{
  border-top:1px solid var(--line);padding:22px 30px;font-size:13px;color:var(--ink-faint);
  display:flex;justify-content:space-between;gap:12px;flex-wrap:wrap;background:var(--card);
}
/* --- article --- */
.meta{font-size:13.5px;color:var(--ink-faint);margin:0 0 6px}
h1{font-size:32px;line-height:1.35;color:var(--navy);margin:0 0 14px;font-weight:700}
.lede{font-size:17.5px;color:var(--ink-soft);margin:0 0 8px}
.article h2{
  font-size:22px;color:var(--navy);margin:2.4em 0 .8em;
  padding-top:1em;border-top:1px solid var(--line);
}
.article h3{font-size:18px;color:var(--navy);margin:1.8em 0 .6em}
.article p{margin:0 0 1.1em}
.article ul,.article ol{margin:0 0 1.2em;padding-left:1.5em}
.article li{margin-bottom:.4em}
figure{margin:1.8em 0}
figure img{max-width:100%;height:auto;border:1px solid var(--line);border-radius:8px;display:block;margin:0 auto;background:#fff}
figure.duo{display:grid;grid-template-columns:1fr 1fr;gap:16px}
figure.duo img{width:100%}
figcaption{font-size:13px;color:var(--ink-faint);margin-top:8px;text-align:center}
table{width:100%;border-collapse:collapse;font-size:14.5px;margin:1.4em 0;background:var(--card)}
th,td{padding:10px 12px;border-bottom:1px solid var(--line);text-align:left;vertical-align:top;line-height:1.65}
th{color:var(--navy);border-bottom:2px solid var(--line);font-weight:600;background:var(--soft)}
blockquote{
  margin:1.4em 0;padding:12px 18px;border-left:3px solid var(--accent);
  background:var(--soft);color:var(--ink-soft);font-size:15.5px;
}
code{background:var(--soft);border:1px solid var(--line);border-radius:4px;padding:1px 6px;font-size:14px;font-family:ui-monospace,Consolas,monospace}
.note{
  margin:1.4em 0;padding:12px 16px;border-left:3px solid var(--accent);
  background:var(--soft);font-size:15px;color:var(--ink-soft);
}
/* --- home cards --- */
.intro{font-size:17.5px;color:var(--ink-soft);max-width:38em;margin:0 0 34px}
.intro strong{color:var(--navy)}
.cardlist{list-style:none;margin:0;padding:0;display:grid;gap:14px}
.card{
  display:block;background:var(--card);border:1px solid var(--line);border-radius:10px;
  padding:20px 22px;text-decoration:none;color:inherit;
}
.card:hover{border-color:var(--accent)}
.card h2{font-size:18.5px;color:var(--navy);margin:0 0 6px;line-height:1.5}
.card p{margin:0;font-size:14.5px;color:var(--ink-soft)}
.card .tag{display:inline-block;font-size:12px;color:var(--accent);letter-spacing:.14em;margin-bottom:8px}
.cardfoot{display:flex;justify-content:space-between;align-items:baseline;gap:12px;flex-wrap:wrap;margin-top:14px}
.cardmeta{font-size:12.5px;color:var(--ink-faint);letter-spacing:.02em}
.readmore{font-size:13.5px;color:var(--accent);font-weight:500;white-space:nowrap;transition:transform 160ms cubic-bezier(.4,0,.2,1)}
.card:hover .readmore{transform:translateX(3px)}
@media (prefers-reduced-motion:reduce){.readmore{transition:none}}
.updated{margin:-18px 0 30px;font-size:13.5px;color:var(--ink-faint)}
.promise{margin-top:38px;padding:16px 20px;border-left:3px solid var(--accent);background:var(--soft);font-size:14.5px;color:var(--ink-soft)}
.sect{margin-top:36px}
.sect:first-of-type{margin-top:0}
.sect h2{font-size:14px;color:var(--ink-faint);font-weight:600;letter-spacing:.24em;margin:0 0 14px}
@media (max-width:560px){
  figure.duo{grid-template-columns:1fr}
  h1{font-size:26px}
  header.site{padding:16px 20px}
  main{padding:32px 20px 48px}
}