:root{
  --ink:#202420;
  --muted:#69736e;
  --line:#e1e6e2;
  --line-strong:#cfd7d2;
  --paper:#ffffff;
  --paper-soft:#f8faf8;
  --learn:#2f776c;
  --learn-soft:#eaf2ef;
  --jp:#214f77;
  --travel:#b27b00;
  --tools:#343b3a;
  --footer:#292a25;
  --serif:"Noto Serif TC","Songti TC","PMingLiU",serif;
  --sans:"Noto Sans TC","PingFang TC","Microsoft JhengHei",system-ui,sans-serif;
  --max:1120px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth;background:var(--paper);color:var(--ink);font-family:var(--sans)}
body{margin:0;background:var(--paper);line-height:1.72}
a{color:inherit}
.shell{width:min(var(--max),calc(100% - 72px));margin-inline:auto}
.skip{
  position:fixed;left:12px;top:10px;z-index:1000;
  transform:translateY(-150%);padding:8px 12px;
  background:#fff;border:1px solid var(--ink);font-size:12px;text-decoration:none
}
.skip:focus{transform:none}

/* Header */
.site-head{
  position:sticky;top:0;z-index:50;
  background:rgba(255,255,255,.97);
  border-bottom:1px solid var(--line);
  backdrop-filter:blur(12px)
}
.head-in{min-height:72px;display:flex;align-items:center;gap:24px}
.brand{display:flex;align-items:center;gap:10px;text-decoration:none;flex:0 0 auto}
.site-mark{
  width:40px;height:40px;display:grid;place-items:center;
  border:1.5px solid var(--learn);
  background:#fff;color:var(--learn);
  font:700 22px/1 var(--serif);
  transition:transform .18s ease,background .18s ease,color .18s ease,box-shadow .18s ease
}
.brand:hover .site-mark,
.brand:focus-visible .site-mark{
  transform:translate(-2px,-2px);
  background:var(--learn);color:#fff;
  box-shadow:5px 5px 0 #dcebe5
}
.brand:focus-visible{outline:3px solid rgba(47,119,108,.12);outline-offset:5px}
.brand-copy strong{display:block;font-family:var(--serif);font-size:16px;line-height:1.25}
.brand-copy small{display:block;margin-top:3px;color:var(--muted);font-size:10px;white-space:nowrap}

.nav{margin-left:auto;display:flex;gap:26px;align-items:center}
.nav a{
  --c:#555f5c;position:relative;color:var(--c);
  font-size:12px;font-weight:800;text-decoration:none;padding:8px 0
}
.nav .nav-japanese{--c:var(--jp)}
.nav .nav-learning{--c:var(--learn)}
.nav .nav-travel{--c:var(--travel)}
.nav .nav-tools{--c:var(--tools)}
.nav a::after{
  content:"";position:absolute;left:0;right:0;bottom:2px;height:1px;
  background:currentColor;transform:scaleX(0);transform-origin:left;
  transition:transform .18s ease
}
.nav a:hover::after,.nav a[aria-current="page"]::after{transform:scaleX(1)}

/* Intro */
.intro{
  border-bottom:1px solid var(--line);
  background:
    linear-gradient(90deg,#fff 0%,#fff 76%,rgba(47,119,108,.035) 100%);
}
.intro-in{
  display:grid;
  grid-template-columns:minmax(0,1fr) 220px;
  gap:72px;
  align-items:end;
  padding:60px 0 48px;
}
.kicker{
  margin:0 0 10px;color:var(--learn);
  font-size:9px;font-weight:850;letter-spacing:.14em
}
.intro h1{
  margin:0;font-family:var(--serif);
  font-size:clamp(48px,5vw,64px);
  font-weight:620;line-height:1.05;letter-spacing:-.02em
}
.intro-copy{
  max-width:46em;margin:17px 0 0;color:#56615c;
  font-size:13px;line-height:1.85
}
.intro-meta{
  padding-top:10px;border-top:1px solid var(--learn);
  display:grid;grid-template-columns:1fr 1fr;gap:18px
}
.intro-meta div{min-width:0}
.intro-meta strong{
  display:block;font-family:var(--serif);font-size:28px;font-weight:600;line-height:1
}
.intro-meta span{display:block;margin-top:6px;color:var(--muted);font-size:9px}

/* General section */
.section{padding:46px 0}
.section-head{
  display:flex;justify-content:space-between;align-items:end;gap:20px;
  padding-bottom:11px;border-bottom:1px solid var(--ink)
}
.section-head h2{
  margin:0;font-family:var(--serif);font-size:24px;font-weight:650
}
.section-head p{margin:0;color:var(--muted);font-size:10.5px}

/* Topic index */
.topic-index{border-bottom:1px solid var(--line)}
.topic-link{
  display:grid;
  grid-template-columns:190px minmax(0,1fr) 72px 20px;
  gap:24px;align-items:center;
  padding:18px 0;
  border-top:1px solid var(--line);
  text-decoration:none
}
.topic-link:first-child{border-top:0}
.topic-link strong{
  font-family:var(--serif);font-size:18px;font-weight:650
}
.topic-link small{color:var(--muted);font-size:10.5px}
.topic-count{color:#87908c;font-size:9px;text-align:right}
.topic-arrow{color:var(--learn);text-align:right;transition:transform .16s ease}
.topic-link:hover strong{color:var(--learn)}
.topic-link:hover .topic-arrow{transform:translateX(3px)}

/* Grouped articles */
.article-groups{padding-top:0}
.article-group{
  scroll-margin-top:92px;
  padding:46px 0 0
}
.group-head{
  display:grid;
  grid-template-columns:190px minmax(0,1fr);
  gap:24px;align-items:end;
  padding-bottom:10px;border-bottom:1px solid var(--line-strong)
}
.group-head h3{
  margin:0;font-family:var(--serif);font-size:23px;font-weight:650
}
.group-head p{
  margin:0;color:var(--muted);font-size:10.5px
}
.article-list{border-bottom:1px solid var(--line)}
.article-row{
  display:grid;
  grid-template-columns:60px minmax(0,1fr) 22px;
  gap:24px;align-items:center;
  padding:20px 0;border-top:1px solid var(--line);
  text-decoration:none
}
.article-row:first-child{border-top:0}
.article-no{
  align-self:start;padding-top:3px;
  color:var(--learn);font-size:9px;font-weight:800;letter-spacing:.08em
}
.article-main strong{
  display:block;font-family:var(--serif);
  font-size:17px;line-height:1.46;font-weight:650
}
.article-main small{
  display:block;margin-top:4px;color:var(--muted);
  font-size:10.5px;line-height:1.72
}
.article-arrow{color:var(--learn);text-align:right;transition:transform .16s ease}
.article-row:hover .article-main strong{color:var(--learn)}
.article-row:hover .article-arrow{transform:translateX(3px)}

.back-link{
  display:inline-flex;align-items:center;gap:7px;
  margin-top:12px;color:#7b8580;font-size:9px;text-decoration:none
}
.back-link:hover{color:var(--learn)}

/* Footer */
.footer{
  margin-top:64px;background:var(--footer);color:#f2f2ed;
  padding:34px 0 40px
}
.footer-in{display:flex;justify-content:space-between;gap:30px}
.footer-links{display:flex;flex-wrap:wrap;gap:10px 18px}
.footer a{color:inherit;font-size:10.5px;text-decoration:none}
.footer a:hover{text-decoration:underline}
.footer p{margin:0;color:#b9bbb4;font-size:10.5px}

@media(max-width:1000px){
  .shell{width:calc(100% - 48px)}
  .intro-in{grid-template-columns:minmax(0,1fr) 190px;gap:44px;padding:50px 0 42px}
  .topic-link,.group-head{grid-template-columns:165px minmax(0,1fr)}
  .topic-link{grid-template-columns:165px minmax(0,1fr) 62px 20px}
}

@media(max-width:720px){
  .shell{width:calc(100% - 28px)}
  .site-head{position:relative}
  .head-in{min-height:auto;display:grid;grid-template-columns:1fr;padding:11px 0 0;gap:8px}
  .site-mark{width:35px;height:35px;font-size:19px}
  .brand-copy strong{font-size:14.5px}.brand-copy small{font-size:8.5px}
  .nav{
    width:calc(100% + 28px);margin-left:-14px;
    display:grid;grid-template-columns:repeat(4,1fr);gap:0;
    border-top:1px solid var(--line);border-bottom:1px solid var(--line)
  }
  .nav a{
    min-height:48px;display:flex;align-items:center;justify-content:center;
    border-right:1px solid var(--line);font-size:10.5px;padding:0 4px
  }
  .nav a:last-child{border-right:0}
  .nav a[aria-current="page"]{background:rgba(47,119,108,.045)}
  .nav a::after{left:10px;right:10px;bottom:0;height:2px}

  .intro{background:#fff}
  .intro-in{display:block;padding:34px 0 30px}
  .intro h1{font-size:42px}
  .intro-copy{font-size:12px;margin-top:12px}
  .intro-meta{margin-top:24px;max-width:220px}

  .section{padding:34px 0}
  .section-head{display:block}
  .section-head h2{font-size:21px}
  .section-head p{margin-top:4px}

  .topic-link{
    grid-template-columns:minmax(0,1fr) 50px 18px;
    grid-template-areas:
      "title count arrow"
      "desc count arrow";
    gap:2px 10px;padding:15px 0
  }
  .topic-link strong{grid-area:title;font-size:16px}
  .topic-link small{grid-area:desc;font-size:10px}
  .topic-count{grid-area:count}
  .topic-arrow{grid-area:arrow}

  .article-group{padding-top:38px}
  .group-head{display:block;padding-bottom:9px}
  .group-head h3{font-size:20px}
  .group-head p{margin-top:3px}

  .article-row{
    grid-template-columns:42px minmax(0,1fr) 18px;
    gap:10px;padding:16px 0
  }
  .article-main strong{font-size:15px}
  .article-main small{font-size:10px}
  .article-no{font-size:8px}
  .footer{margin-top:48px;padding:28px 0 32px}
  .footer-in{display:block}.footer p{margin-top:10px}
}

@media(max-width:390px){
  .shell{width:calc(100% - 24px)}
  .nav{width:calc(100% + 24px);margin-left:-12px}
  .intro h1{font-size:39px}
  .article-row{grid-template-columns:36px minmax(0,1fr) 16px}
}