:root {
  --a-bg:        #FBFAF7;
  --a-bg-warm:   #F2EEE3;
  --a-ink:       #1A1A1A;
  --a-ink-soft:  #3A3A3A;
  --a-mute:      #8A8A8A;
  --a-rule:      #E6E2D8;
  --a-accent:    #9C2A1F;

  --a-serif:     "Noto Serif JP", "Hiragino Mincho ProN", "Yu Mincho", serif;
  --a-mono:      ui-monospace, "SF Mono", Menlo, Consolas, monospace;

  --a-pad-page:    80px;
  --a-pad-page-sm: 24px;
  --a-row-pad:     26px;

  --a-h1: 44px; --a-h2: 27px; --a-h3: 24px;
  --a-body: 18px; --a-small: 15px; --a-caption: 13px;
  --a-leading: 1.8;
  --a-tracking-jp: 0.04em;
}

@media (prefers-color-scheme: dark) {
  :root {
    --a-bg:       #171511;
    --a-bg-warm:  #1F1C16;
    --a-ink:      #EFEBDF;
    --a-ink-soft: #C8C2B3;
    --a-mute:     #8A8478;
    --a-rule:     #2A2620;
  }
}

html, body { background: var(--a-bg); color: var(--a-ink); }
body { font-family: var(--a-serif); font-size: var(--a-body); line-height: var(--a-leading); }

a { color: inherit; text-decoration: none; transition: color .15s; }
a:hover { color: var(--a-accent); }

:focus-visible { outline: 2px solid var(--a-accent); outline-offset: 3px; }
:focus:not(:focus-visible) { outline: none; }

h1 { font-size: var(--a-h1); font-weight: 500; letter-spacing: 0.01em; line-height: 1.4; }
h2 { font-size: var(--a-h2); font-weight: 500;
     border-left: 3px solid var(--a-accent); padding-left: 14px;
     margin: 40px 0 14px; }
h3 { font-size: var(--a-h3); font-weight: 500; line-height: 1.5; }

time, .tag, code, pre { font-family: var(--a-mono); }

pre {
  background: var(--a-bg-warm);
  border-left: 2px solid var(--a-ink);
  padding: 18px 22px;
  font-size: 13px; line-height: 1.85;
  overflow: auto;
}
code { background: var(--a-bg-warm); padding: 1px 6px; font-size: 0.9em; }
pre code { background: none; padding: 0; font-size: inherit; }

hr, .rule { border: 0; border-top: 1px solid var(--a-rule); }

table { width: 100%; border-collapse: collapse; font-size: 0.95em; margin: 24px 0; }
thead tr { background: var(--a-ink); color: var(--a-bg); }
th { padding: 10px 16px; text-align: left; font-weight: 500; }
td { padding: 10px 16px; border-bottom: 1px solid var(--a-rule); }
tbody tr:nth-child(even) { background: var(--a-bg-warm); }
tbody tr:hover { background: color-mix(in srgb, var(--a-accent) 6%, var(--a-bg)); }

img { max-width: 100%; height: auto; }

.mono { font-family: var(--a-mono); }

.skip-link {
  position: absolute; top: -100%; left: 16px;
  background: var(--a-ink); color: var(--a-bg);
  padding: 8px 16px; font-family: var(--a-mono); font-size: var(--a-small);
  z-index: 200; transition: top .1s;
}
.skip-link:focus { top: 8px; }
/* ─── Site Header ─── */
.site-header {
  padding: 32px var(--a-pad-page) 24px;
  border-bottom: 1px solid var(--a-ink);
  display: flex; justify-content: space-between; align-items: flex-end;
}
.site-header .brand { text-decoration: none; }
.site-header .brand small {
  display: block;
  font-family: var(--a-mono); font-size: 11px;
  letter-spacing: 0.3em; text-transform: uppercase; color: var(--a-mute);
}
.site-header h1 {
  font-size: 38px; letter-spacing: var(--a-tracking-jp); margin: 8px 0 0;
  border: none; /* reset base h1/h2 */
}
.site-nav { display: flex; gap: 28px; font-size: 15px; }

/* ─── List Header (tags / archives) ─── */
.list-header {
  padding: 40px var(--a-pad-page) 24px;
  border-bottom: 1px solid var(--a-rule);
}
.list-header h1 { font-size: var(--a-h2); margin: 0; }

/* ─── Featured Post ─── */
.featured {
  display: grid; grid-template-columns: 140px 1fr; gap: 64px;
  padding: 56px var(--a-pad-page) 28px; border-bottom: 1px solid var(--a-rule);
}
.featured .meta { display: flex; flex-direction: column; gap: 8px; }
.featured .kicker {
  font-family: var(--a-mono); font-size: 11px;
  letter-spacing: 0.25em; color: var(--a-accent);
}
.featured h2 {
  font-size: 48px; line-height: 1.4; margin: 0 0 18px;
  border-left: none; padding-left: 0; /* reset base h2 */
}
.featured p { font-size: 17px; line-height: 2; color: var(--a-ink-soft); max-width: 720px; }

/* ─── Post List ─── */
.post-list { padding: 8px var(--a-pad-page) 16px; }

.post-row {
  display: grid; grid-template-columns: 140px 1fr 120px; gap: 64px;
  padding: var(--a-row-pad) 0; border-bottom: 1px solid var(--a-rule);
  align-items: flex-start;
  color: inherit; text-decoration: none; /* <a> reset */
}
.post-row:hover { background: var(--a-bg-warm); }
.post-row:hover .post-title { color: var(--a-accent); }
.post-row time { font-family: var(--a-mono); color: var(--a-mute); font-size: var(--a-small); }
.post-row .tag { font-family: var(--a-mono); color: var(--a-accent); text-align: right; font-size: var(--a-small); }
.post-body { display: flex; flex-direction: column; gap: 4px; }
.post-summary { font-size: var(--a-small); color: var(--a-ink-soft); line-height: 1.7; }

/* ─── Tag Pills (featured) ─── */
.tag-pill {
  display: inline-block; padding: 3px 10px;
  border: 1px solid var(--a-accent); color: var(--a-accent);
  font-family: var(--a-mono); font-size: 11px;
  margin-right: 6px; margin-top: 12px;
}
.tag-pill:hover { background: var(--a-accent); color: var(--a-bg); }

/* ─── Terms (タグ一覧) ─── */
.terms-list {
  padding: 32px var(--a-pad-page) 48px;
  display: flex; flex-wrap: wrap; gap: 12px;
  list-style: none; margin: 0;
}
.term-item {
  display: flex; align-items: baseline; gap: 6px;
  padding: 8px 16px;
  border: 1px solid var(--a-rule);
  font-family: var(--a-mono); font-size: var(--a-small);
  color: inherit; text-decoration: none;
}
.term-item:hover { border-color: var(--a-accent); color: var(--a-accent); }
.term-count { font-size: var(--a-caption); color: var(--a-mute); }
.term-item:hover .term-count { color: var(--a-accent); }

/* ─── Pagination ─── */
.pagination-nav {
  display: flex; align-items: center; justify-content: center; gap: 8px;
  padding: 20px var(--a-pad-page);
  border-top: 1px solid var(--a-rule);
}
.page-numbers { display: flex; align-items: center; gap: 2px; flex-wrap: wrap; }
.page-btn {
  font-family: var(--a-mono); font-size: var(--a-small);
  padding: 0 10px; height: 32px;
  display: flex; align-items: center;
  border: 1px solid var(--a-rule); color: var(--a-ink-soft);
}
.page-btn:hover { border-color: var(--a-accent); color: var(--a-accent); }
.page-btn.disabled { color: var(--a-mute); pointer-events: none; border-color: transparent; }
.page-num {
  font-family: var(--a-mono); font-size: var(--a-small);
  min-width: 32px; height: 32px;
  display: flex; align-items: center; justify-content: center;
  border: 1px solid transparent; color: var(--a-ink-soft);
}
.page-num:hover { border-color: var(--a-rule); color: var(--a-accent); }
.page-num.current {
  background: var(--a-ink); color: var(--a-bg);
  border-color: var(--a-ink);
}
.page-ellipsis {
  font-family: var(--a-mono); font-size: var(--a-small);
  color: var(--a-mute); padding: 0 4px;
  display: flex; align-items: center; height: 32px;
}

/* ─── In-feed ad ─── */
.infeed-ad { padding: var(--a-row-pad) 0; border-bottom: 1px solid var(--a-rule); }

/* ─── Article prose link ─── */
.article .prose a { text-decoration: underline; text-decoration-color: var(--a-rule); text-underline-offset: 3px; }
.article .prose a:hover { text-decoration-color: var(--a-accent); }

/* ─── Heading anchor ─── */
.heading-anchor {
  font-family: var(--a-mono); font-size: 0.75em; font-weight: 400;
  color: var(--a-mute); text-decoration: none; margin-right: 0.4em;
  opacity: 0; transition: opacity .15s;
}
:is(h2, h3, h4):hover .heading-anchor { opacity: 1; }

/* ─── Archive Years ─── */
.archives-years {
  padding: 32px var(--a-pad-page) 48px;
  display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 12px;
}
.archive-year-item {
  display: flex; align-items: baseline; justify-content: space-between;
  padding: 16px 20px;
  border: 1px solid var(--a-rule);
  color: inherit; text-decoration: none;
}
.archive-year-item:hover { border-color: var(--a-accent); color: var(--a-accent); }
.archive-year { font-family: var(--a-mono); font-size: var(--a-h3); font-weight: 500; }
.archive-year-item:hover .archive-year { color: var(--a-accent); }

/* ─── Article (Single) ─── */
.article { max-width: 900px; margin: 0 auto; padding: 64px 32px; }
.article .kicker {
  font-family: var(--a-mono); font-size: 11px;
  letter-spacing: 0.25em; color: var(--a-accent); margin-bottom: 18px;
}
.article .kicker .dot { margin: 0 6px; }
.article h1 { font-size: 44px; line-height: 1.4; margin: 0 0 28px; }
.article .byline {
  display: flex; gap: 14px; align-items: center;
  margin-bottom: 36px; padding-bottom: 24px; border-bottom: 1px solid var(--a-rule);
}
.article .avatar {
  width: 36px; height: 36px; border-radius: 50%;
  object-fit: cover; flex-shrink: 0;
}
.article .byline .name { font-weight: 500; font-size: var(--a-small); }
.byline-meta { display: flex; gap: 12px; align-items: center; }
.article .byline .read { font-family: var(--a-mono); font-size: var(--a-caption); color: var(--a-mute); }
.article .byline .updated { font-family: var(--a-mono); font-size: var(--a-caption); color: var(--a-accent); }

.article .prose p { font-size: 18px; line-height: var(--a-leading); margin: 0 0 18px; text-indent: 1em; }
.article .prose p:first-child { font-size: 19px; }
.article .prose blockquote {
  border-left: 3px solid var(--a-accent);
  padding: 4px 0 4px 16px; color: var(--a-ink-soft); margin: 24px 0;
}
.article .prose ul, .article .prose ol { padding-left: 1.5em; margin: 0 0 18px; }
.article .prose li { line-height: var(--a-leading); }

/* ─── Share Buttons ─── */
.share { display: flex; gap: 8px; margin: 40px 0 0; }
.share-btn {
  font-family: var(--a-mono); font-size: var(--a-caption);
  padding: 6px 16px; border: 1px solid var(--a-rule);
  color: var(--a-ink-soft); background: none; cursor: pointer;
  letter-spacing: 0.05em; transition: border-color .15s, color .15s;
  text-decoration: none;
}
.share-btn:hover { border-color: var(--a-accent); color: var(--a-accent); }

.adsense-container { margin: 40px 0; }

/* ─── Prev/Next ─── */
.prev-next {
  margin-top: 64px; padding-top: 28px;
  border-top: 1px solid var(--a-ink);
  display: grid; grid-template-columns: 1fr 1fr; gap: 32px;
}
.prev-next .next { text-align: right; }
.prev-next .next:first-child { grid-column: 2; }
.prev-next small {
  display: block; font-family: var(--a-mono);
  font-size: 11px; color: var(--a-mute); margin-bottom: 6px;
}
.prev-next strong { display: block; font-weight: 500; line-height: 1.5; }
.prev-next a:hover strong { color: var(--a-accent); }

/* ─── Site Footer ─── */
.site-footer {
  padding: 28px var(--a-pad-page);
  border-top: 1px solid var(--a-ink); background: var(--a-bg-warm);
  display: flex; justify-content: space-between; align-items: center;
}
.site-footer .who { display: flex; gap: 14px; align-items: center; }
.site-footer .avatar {
  width: 36px; height: 36px; border-radius: 50%;
  object-fit: cover; flex-shrink: 0;
}
.site-footer .meta { font-family: var(--a-mono); font-size: var(--a-small); color: var(--a-mute); }
.site-footer .meta a { color: var(--a-mute); }
.site-footer .meta a:hover { color: var(--a-accent); }

/* ─── Mobile nav toggle ─── */
.nav-toggle {
  display: none;
  flex-direction: column; gap: 5px;
  background: none; border: none; cursor: pointer; padding: 4px;
}
.nav-toggle span {
  display: block; width: 22px; height: 2px; background: var(--a-ink);
  transition: transform .2s, opacity .2s;
}

/* ─── Tablet (960px) ─── */
@media (max-width: 960px) {
  :root { --a-pad-page: 40px; }
  .post-row { grid-template-columns: 120px 1fr 100px; gap: 24px; }
  .featured { gap: 32px; }
}

/* ─── Code copy button ─── */
.highlight { position: relative; }
.copy-btn {
  position: absolute; top: 10px; right: 10px;
  font-family: var(--a-mono); font-size: var(--a-caption);
  padding: 3px 10px; border: 1px solid var(--a-rule);
  background: var(--a-bg-warm); color: var(--a-mute); cursor: pointer;
  opacity: 0; transition: opacity .15s;
}
.highlight:hover .copy-btn { opacity: 1; }
.copy-btn.copied { color: var(--a-accent); border-color: var(--a-accent); }

/* ─── Search page ─── */
.search-wrap { padding: 24px var(--a-pad-page) 48px; }
#pagefind-search {
  --pagefind-ui-primary: var(--a-accent);
  --pagefind-ui-text: var(--a-ink);
  --pagefind-ui-background: var(--a-bg);
  --pagefind-ui-border: var(--a-rule);
  --pagefind-ui-tag: var(--a-bg-warm);
  --pagefind-ui-border-width: 1px;
  --pagefind-ui-border-radius: 0;
  --pagefind-ui-font: var(--a-serif);
  max-width: 860px;
}

/* ─── Amazon Card ─── */
.amazon-card {
  border: 1px solid var(--a-rule); margin: 24px 0;
}
.amazon-card a {
  display: flex; gap: 20px; padding: 16px;
  text-decoration: none; color: inherit;
}
.amazon-card a:hover { background: var(--a-bg-warm); }
.amazon-img {
  width: 120px; height: 120px; object-fit: contain; flex-shrink: 0; background: #fff;
}
.amazon-body {
  display: flex; flex-direction: column; justify-content: center; gap: 12px;
}
.amazon-title { font-size: var(--a-small); line-height: 1.6; }
.amazon-btn {
  display: inline-block; font-family: var(--a-mono); font-size: var(--a-caption);
  padding: 6px 14px; border: 1px solid var(--a-accent); color: var(--a-accent); width: fit-content;
}
.amazon-card a:hover .amazon-btn { background: var(--a-accent); color: var(--a-bg); }

/* ─── Related Articles ─── */
.related { margin: 48px 0 0; padding-top: 28px; border-top: 1px solid var(--a-rule); }
.related-heading {
  font-family: var(--a-mono); font-size: 11px; letter-spacing: 0.25em;
  color: var(--a-mute); border: none; padding: 0; margin: 0 0 16px;
}
.related-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px; }
.related-item {
  padding: 16px; border: 1px solid var(--a-rule);
  display: flex; flex-direction: column; gap: 6px;
  text-decoration: none; color: inherit;
}
.related-item:hover { border-color: var(--a-accent); }
.related-item time { font-family: var(--a-mono); font-size: var(--a-caption); color: var(--a-mute); }
.related-title { font-size: var(--a-small); line-height: 1.5; }
.related-item:hover .related-title { color: var(--a-accent); }

/* ─── Read time in post-row ─── */
.post-date { display: flex; flex-direction: column; gap: 2px; }
.post-row .read-time {
  font-family: var(--a-mono); font-size: var(--a-caption); color: var(--a-mute);
}

/* ─── Archive count ─── */
.archive-count { font-family: var(--a-mono); font-size: var(--a-caption); color: var(--a-mute); }

/* ─── 404 page ─── */
.error-page { max-width: 600px; margin: 80px auto; padding: 0 32px; text-align: center; }
.error-code {
  font-family: var(--a-mono); font-size: 120px; font-weight: 500; color: var(--a-rule);
  line-height: 1; margin-bottom: 24px;
}
.error-page h1 { font-size: var(--a-h2); margin: 0 0 12px; }
.error-page p { color: var(--a-ink-soft); margin-bottom: 32px; }
.error-link { font-family: var(--a-mono); font-size: var(--a-small); }
.error-link:hover { color: var(--a-accent); }

/* ─── Mobile (720px) ─── */
@media (max-width: 720px) {
  :root { --a-pad-page: var(--a-pad-page-sm); }

  /* ナビゲーション */
  .site-header { flex-wrap: wrap; align-items: center; }
  .nav-toggle { display: flex; }
  .site-nav {
    display: none; flex-direction: column; gap: 16px;
    width: 100%; padding: 16px 0 8px;
    border-top: 1px solid var(--a-rule); order: 3;
  }
  .site-nav.open { display: flex; }

  .featured { grid-template-columns: 1fr; gap: 12px; }
  .featured h2 { font-size: 32px; }
  .post-row { grid-template-columns: 1fr; gap: 4px; }
  .post-row .tag { text-align: left; }
  .article h1 { font-size: 32px; }
  .related-grid { grid-template-columns: 1fr; }
  .amazon-card a { flex-direction: column; }
  .amazon-img { width: 100%; height: 160px; }
  .prev-next { grid-template-columns: 1fr; gap: 16px; }
  .prev-next .next:first-child { grid-column: 1; text-align: left; }
  .site-footer { flex-direction: column; align-items: flex-start; gap: 16px; }
}