:root {
  color-scheme: light;
  --ink: #173c3c;
  --muted: #557674;
  --paper: #fffdf2;
  --teal: #277f78;
  --deep: #155f60;
  --line: #d5e5dd;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; color: var(--ink); font-family: "Yu Gothic UI", "Hiragino Kaku Gothic ProN", system-ui, sans-serif; line-height: 1.75; background: radial-gradient(circle at 15% 8%, rgba(255,255,255,.8), transparent 26%), linear-gradient(145deg, #a9dfd7, #f2d79c); }
a { color: var(--deep); text-underline-offset: .18em; }
a:focus-visible { outline: 3px solid #e89b4a; outline-offset: 3px; border-radius: 4px; }
.site-header { padding: 38px max(24px, calc((100% - 1020px) / 2)); color: #fffdf2; background: linear-gradient(135deg, rgba(22,108,103,.96), rgba(66,157,143,.92)); box-shadow: 0 12px 36px rgba(27,79,75,.2); }
.site-header > p:first-of-type { margin: 32px 0 8px; color: #ffe39a; font: 800 13px Georgia, serif; letter-spacing: .24em; }
.site-header h1 { margin: 0; font-family: Georgia, "Yu Mincho", serif; font-size: clamp(34px, 6vw, 58px); line-height: 1.15; }
.site-header h1 span { font-size: .56em; letter-spacing: .05em; }
.lead { margin: 16px 0 0; }
.back-link { display: inline-flex; min-height: 44px; align-items: center; border: 1px solid rgba(255,255,255,.7); border-radius: 999px; padding: 0 16px; color: #fff; font-weight: 800; text-decoration: none; background: rgba(255,255,255,.12); }
.site-header nav { display: flex; gap: 10px; margin-top: 22px; }
.site-header nav a { display: inline-flex; min-height: 44px; align-items: center; border-radius: 999px; padding: 0 18px; color: var(--deep); font-weight: 900; text-decoration: none; background: #fff9dc; }
main { width: min(1068px, calc(100% - 32px)); margin: 34px auto 54px; display: grid; gap: 28px; }
article { scroll-margin-top: 18px; border: 1px solid rgba(255,255,255,.85); border-radius: 26px; padding: clamp(24px, 5vw, 52px); background: rgba(255,253,242,.96); box-shadow: 0 18px 48px rgba(31,87,80,.16); }
.section-label { margin: 0 0 8px; color: var(--teal); font-size: 12px; font-weight: 900; letter-spacing: .2em; text-transform: uppercase; }
h2 { margin: 0; font-family: Georgia, "Yu Mincho", serif; font-size: clamp(28px, 4vw, 42px); line-height: 1.25; }
.updated { margin: 8px 0 0; color: var(--muted); font-size: 13px; }
section { margin-top: 34px; padding-top: 30px; border-top: 1px solid var(--line); }
h3 { margin: 0 0 10px; color: var(--deep); font-size: 20px; line-height: 1.4; }
p { margin: 10px 0 0; }
ul { margin: 12px 0 0; padding-left: 1.45em; }
li + li { margin-top: 8px; }
footer { padding: 26px; text-align: center; background: rgba(255,253,242,.82); }
footer a { font-weight: 900; }
@media (min-width: 880px) {
  main { grid-template-columns: 1fr 1fr; align-items: start; }
  article { padding: 36px; }
}
@media (max-width: 520px) {
  .site-header { padding: 24px 18px 30px; }
  .site-header > p:first-of-type { margin-top: 24px; }
  main { width: min(100% - 20px, 1068px); margin-top: 18px; gap: 18px; }
  article { border-radius: 19px; padding: 23px 19px; }
  section { margin-top: 27px; padding-top: 24px; }
}
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }