/* それ、宇宙 — ベーススタイル
   ライト/ダーク両対応。読み物として長文が読めることだけを優先する。 */

:root {
  --bg: #ffffff;
  --fg: #14161a;
  --muted: #5c6470;
  --line: #e4e7ec;
  --accent: #1b4fd8;
  --card: #f7f8fa;
  --maxw: 720px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0e1116;
    --fg: #e8eaee;
    --muted: #9aa3b0;
    --line: #232833;
    --accent: #7aa2ff;
    --card: #161b23;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: "Noto Sans JP", system-ui, -apple-system, "Hiragino Kaku Gothic ProN", sans-serif;
  line-height: 1.9;
  -webkit-text-size-adjust: 100%;
}

.wrap { width: min(100% - 2.5rem, var(--maxw)); margin-inline: auto; }

a { color: var(--accent); }

/* ---- ナビ ---- */
#nav { border-bottom: 1px solid var(--line); position: sticky; top: 0; background: var(--bg); z-index: 10; }
.nav-in { display: flex; align-items: center; justify-content: space-between; height: 56px; }
.logo { font-weight: 900; letter-spacing: .02em; text-decoration: none; color: var(--fg); }
.nav-links { display: flex; gap: 1.25rem; list-style: none; margin: 0; padding: 0; font-size: .9rem; }
.nav-links a { text-decoration: none; color: var(--muted); }
.nav-links a:hover { color: var(--fg); }

/* ---- トップ ---- */
.hero { padding: 4rem 0 3rem; border-bottom: 1px solid var(--line); }
.hero h1 { font-size: clamp(2.2rem, 8vw, 3.4rem); font-weight: 900; margin: 0 0 1rem; letter-spacing: .02em; }
.hero-lead { color: var(--muted); font-size: 1.05rem; margin: 0 0 2rem; }
.hero-cta {
  display: inline-block; padding: .8rem 1.8rem; border-radius: 999px;
  background: var(--accent); color: #fff; text-decoration: none; font-weight: 700;
}

.pillars { padding: 3rem 0; }
.pillars h2 { font-size: 1.1rem; color: var(--muted); font-weight: 700; margin: 0 0 1.25rem; }
.pillars ul { list-style: none; margin: 0; padding: 0; display: grid; gap: .75rem; }
.pillars li {
  background: var(--card); border: 1px solid var(--line); border-radius: 12px;
  padding: 1rem 1.15rem; display: flex; flex-direction: column; gap: .2rem;
}
.pillars strong { font-size: 1rem; }
.pillars span { color: var(--muted); font-size: .9rem; }

/* ---- パンくず ---- */
.crumb { padding: 1rem 0 0; }
.crumb ol { list-style: none; display: flex; flex-wrap: wrap; gap: .5rem; margin: 0; padding: 0; font-size: .8rem; color: var(--muted); }
.crumb li + li::before { content: "›"; margin-right: .5rem; }
.crumb a { color: var(--muted); text-decoration: none; }

/* ---- 記事 ---- */
.post { width: min(100% - 2.5rem, var(--maxw)); margin: 2rem auto 4rem; }
.post-head { margin-bottom: 2rem; }
.post-meta { display: flex; flex-wrap: wrap; gap: .6rem; align-items: center; font-size: .8rem; color: var(--muted); margin-bottom: .75rem; }
.post-meta .tag { background: var(--card); border: 1px solid var(--line); border-radius: 999px; padding: .1rem .7rem; }
.post-head h1 { font-size: clamp(1.6rem, 5.5vw, 2.2rem); line-height: 1.5; font-weight: 900; margin: 0; }

.post-body h2 { font-size: 1.3rem; margin: 2.75rem 0 .9rem; padding-left: .7rem; border-left: 4px solid var(--accent); line-height: 1.5; }
.post-body h3 { font-size: 1.1rem; margin: 2rem 0 .7rem; }
.post-body p { margin: 0 0 1.4rem; }
.post-body ul, .post-body ol { margin: 0 0 1.4rem; padding-left: 1.4rem; }
.post-body li { margin-bottom: .5rem; }
.post-body img { max-width: 100%; height: auto; border-radius: 10px; }
.post-body blockquote {
  margin: 0 0 1.4rem; padding: .9rem 1.1rem; background: var(--card);
  border-left: 3px solid var(--line); color: var(--muted);
}
.post-body code { background: var(--card); padding: .1rem .35rem; border-radius: 4px; font-size: .9em; }
.post-body pre { background: var(--card); padding: 1rem; border-radius: 10px; overflow-x: auto; }
.post-body table { width: 100%; border-collapse: collapse; margin: 0 0 1.4rem; font-size: .92rem; display: block; overflow-x: auto; }
.post-body th, .post-body td { border: 1px solid var(--line); padding: .55rem .7rem; text-align: left; }
.post-body th { background: var(--card); }

/* ---- 記事一覧 ---- */
.list-head { padding: 3rem 0 1.5rem; }
.list-head h1 { font-size: clamp(1.8rem, 6vw, 2.4rem); font-weight: 900; margin: 0 0 .5rem; }
.list-head p { color: var(--muted); margin: 0; }
.post-list { list-style: none; margin: 0 0 4rem; padding: 0; display: grid; gap: 1rem; }
.post-list li { border: 1px solid var(--line); border-radius: 12px; }
.post-list a { display: block; padding: 1.15rem 1.25rem; text-decoration: none; color: inherit; }
.post-list a:hover { background: var(--card); }
.post-list .post-date { display: block; font-size: .78rem; color: var(--muted); margin-bottom: .35rem; }
.post-list h2 { font-size: 1.05rem; margin: 0 0 .4rem; line-height: 1.6; }
.post-list p { margin: 0; font-size: .9rem; color: var(--muted); }

/* ---- フッター ---- */
.site-foot { border-top: 1px solid var(--line); padding: 2.5rem 0 3.5rem; color: var(--muted); font-size: .85rem; }
.foot-brand { font-weight: 900; color: var(--fg); margin: 0 0 .4rem; }
.foot-note { margin: 0 0 .5rem; }
.foot-note.small { font-size: .78rem; line-height: 1.7; }
.foot-links { list-style: none; display: flex; gap: 1rem; margin: 1rem 0 0; padding: 0; }
.foot-links a { color: var(--muted); }