:root{
  --bg:#FBF9F4;
  --ink:#22312E;
  --teal:#0E4F4A;
  --teal-dark:#09332F;
  --coral:#FF6B5B;
  --card:#FFFFFF;
  --line:#E7E0D2;
  --muted:#6B7A75;
}
*{margin:0;padding:0;box-sizing:border-box}
body{
  background:var(--bg);
  color:var(--ink);
  font-family:"Hiragino Kaku Gothic ProN","Hiragino Sans","Noto Sans JP",sans-serif;
  line-height:1.85;
  font-size:16px;
  -webkit-font-smoothing:antialiased;
}
a{color:var(--teal);text-decoration:none}
a:hover{text-decoration:underline}
.wrap{max-width:760px;margin:0 auto;padding:0 20px}
header.site{
  background:var(--teal-dark);
  color:#fff;
  padding:18px 0;
}
header.site .wrap{display:flex;align-items:center;justify-content:space-between}
.logo{font-weight:700;font-size:20px;letter-spacing:.04em;color:#fff}
.logo span{color:var(--coral)}
nav.main a{color:#DDEAE6;margin-left:18px;font-size:14px}
.hero{
  background:linear-gradient(160deg,var(--teal) 0%,var(--teal-dark) 100%);
  color:#fff;
  padding:64px 0 56px;
  text-align:center;
}
.hero h1{font-size:30px;line-height:1.5;font-weight:700;margin-bottom:16px}
.hero h1 .accent{color:#FFB4A8}
.hero p{font-size:16px;color:#DDEAE6;max-width:560px;margin:0 auto 28px}
.btn{
  display:inline-block;background:var(--coral);color:#fff;font-weight:700;
  padding:12px 28px;border-radius:999px;font-size:15px;
}
.btn:hover{text-decoration:none;opacity:.92}
section{padding:44px 0 8px}
h2.sec{
  font-size:21px;font-weight:700;margin-bottom:18px;
  border-left:5px solid var(--coral);padding-left:12px;line-height:1.4;
}
p.lead{margin-bottom:14px}
.themes{display:grid;grid-template-columns:1fr;gap:14px}
@media(min-width:640px){.themes{grid-template-columns:repeat(3,1fr)}}
.theme-card{
  background:var(--card);border:1px solid var(--line);border-radius:14px;padding:20px 18px;
}
.theme-card .num{color:var(--coral);font-weight:700;font-size:13px;letter-spacing:.1em}
.theme-card h3{font-size:16px;margin:6px 0 8px}
.theme-card p{font-size:14px;color:var(--muted);line-height:1.7}
.article-list{display:flex;flex-direction:column;gap:14px}
.article-card{
  background:var(--card);border:1px solid var(--line);border-radius:14px;padding:20px;
  display:block;color:var(--ink);
}
.article-card:hover{text-decoration:none;border-color:var(--teal)}
.article-card .meta{font-size:12px;color:var(--muted);margin-bottom:6px}
.article-card .meta .cat{
  background:var(--teal);color:#fff;border-radius:999px;padding:2px 10px;
  font-size:11px;margin-right:8px;letter-spacing:.05em;
}
.article-card h3{font-size:17px;line-height:1.55;margin-bottom:6px}
.article-card p{font-size:14px;color:var(--muted);line-height:1.7}
.about-box{
  background:var(--card);border:1px solid var(--line);border-radius:14px;padding:22px;
}
.about-box p{font-size:15px;margin-bottom:10px}
.about-box p:last-child{margin-bottom:0}
footer.site{
  margin-top:56px;border-top:1px solid var(--line);
  padding:26px 0 34px;font-size:13px;color:var(--muted);text-align:center;
}
footer.site a{color:var(--muted);margin:0 10px}
article.post{padding:40px 0 10px}
article.post .meta{font-size:13px;color:var(--muted);margin-bottom:10px}
article.post .meta .cat{
  background:var(--teal);color:#fff;border-radius:999px;padding:2px 10px;
  font-size:11px;margin-right:8px;letter-spacing:.05em;
}
article.post h1{font-size:25px;line-height:1.55;margin-bottom:22px}
article.post h2{font-size:19px;margin:32px 0 12px;border-left:5px solid var(--coral);padding-left:12px;line-height:1.4}
article.post p{margin-bottom:16px}
article.post ul{margin:0 0 16px 22px}
article.post li{margin-bottom:6px}
.note{
  background:#F3EFE3;border-radius:12px;padding:16px 18px;font-size:14px;margin:22px 0;
}
.backlink{margin:28px 0 0;font-size:14px}