/* レースの沼 — 共通デザインシステム(ダークレーシングテーマ) */
:root {
  --bg: #0d0f14;
  --bg-alt: #131722;
  --surface: #1a2030;
  --surface-hover: #222a3e;
  --border: #2c3550;
  --text: #e8eaf0;
  --text-dim: #9aa3b8;
  --accent: #e0322e;          /* レーシングレッド */
  --accent-soft: #ff6b5e;
  --gold: #d8a938;            /* チェッカー/トロフィー */
  --blue: #4f8fe8;
  --green: #3fb96b;
  --orange: #e8923f;
  --pit-black: #10131a;
  --radius: .625rem;
  --maxw: 67.5rem;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: system-ui, -apple-system, "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Noto Sans JP", "Yu Gothic", sans-serif;
  font-size: 1rem;
  line-height: 1.65;
  letter-spacing: 0;
}

p, li { line-height: 1.65; letter-spacing: 0; }

a { color: var(--blue); text-decoration: none; }
a:hover { color: var(--accent-soft); text-decoration: underline; }

h1, h2, h3, h4, .site-title, .card-title {
  font-weight: 800;
  letter-spacing: -.02em;
  line-height: 1.15;
}
h1 { font-size: 1.875rem; line-height: 1.08; letter-spacing: -.028em; }
h2 {
  font-size: 1.375rem;
  line-height: 1.12;
  border-left: .3125rem solid var(--accent);
  padding-left: .6em;
  margin-top: 2.2em;
}
h3 { font-size: 1.125rem; line-height: 1.18; color: var(--accent-soft); margin-top: 1.8em; }

main {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 1.2rem 1rem 4rem;
}

/* ===== ヘッダー / ピットボード風ナビ ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  isolation: isolate;
  background: rgba(13, 15, 20, .72);
  -webkit-backdrop-filter: blur(1.25rem) saturate(160%);
  backdrop-filter: blur(1.25rem) saturate(160%);
  padding: .875rem 1rem 0;
  box-shadow: 0 .0625rem 0 rgba(224, 50, 46, .34), 0 .75rem 1.75rem rgba(0, 0, 0, .22);
}
.site-header::after {
  content: "";
  position: absolute;
  z-index: -1;
  right: 0;
  bottom: -1rem;
  left: 0;
  height: 1rem;
  background: linear-gradient(to bottom, rgba(13, 15, 20, .38), transparent);
  pointer-events: none;
}
.site-title-row {
  max-width: var(--maxw);
  margin: 0 auto;
  display: flex;
  align-items: baseline;
  gap: .8rem;
  flex-wrap: wrap;
}
.site-title {
  font-size: 1.625rem;
  line-height: 1.05;
  letter-spacing: -.03em;
  color: var(--text);
  margin: 0;
}
.site-title a { color: var(--text); text-decoration: none; }
.site-title .flag { color: var(--accent); }
.site-sub {
  color: var(--text-dim);
  font-size: .85rem;
  font-weight: 600;
  line-height: 1.3;
  letter-spacing: .08em;
}
.pitboard-nav {
  max-width: var(--maxw);
  margin: .7rem auto 0;
  display: flex;
  flex-wrap: wrap;
  gap: .3rem;
}
.pitboard-nav a {
  display: block;
  padding: .45em .9em;
  background: var(--pit-black);
  color: var(--text-dim);
  border: 1px solid var(--border);
  border-bottom: none;
  border-radius: .5rem .5rem 0 0;
  font-weight: 700;
  font-size: .86rem;
  letter-spacing: .04em;
  text-decoration: none;
  transition: transform 240ms ease-out, opacity 240ms ease-out;
}
.pitboard-nav a:hover {
  color: var(--text);
  background: var(--surface-hover);
  text-decoration: none;
}
.pitboard-nav a.active,
.pitboard-nav a[aria-current="page"] {
  color: #fff;
  background: var(--accent);
  border-color: var(--accent);
}

/* ===== フッター ===== */
.site-footer {
  border-top: 1px solid var(--border);
  margin-top: 3rem;
  padding: 1.4rem 1rem 2.2rem;
  color: var(--text-dim);
  font-size: .84rem;
  text-align: center;
}

/* ===== 自信度バッジ ===== */
.badge {
  display: inline-block;
  font-size: .72rem;
  font-weight: 700;
  padding: .1em .6em;
  border-radius: 999rem;
  vertical-align: middle;
  letter-spacing: .04em;
  white-space: nowrap;
  border: 1px solid transparent;
}
.badge-verified { background: rgba(63,185,107,.16); color: #6fdb96; border-color: #2c7a4b; }
.badge-common   { background: rgba(79,143,232,.16); color: #8ab6f2; border-color: #2f5da0; }
.badge-unverified { background: rgba(232,146,63,.16); color: #f0b06a; border-color: #a06326; }
.badge-check    { background: rgba(224,50,46,.14); color: #f08a86; border-color: #93312e; }
.badge-cat { background: var(--surface-hover); color: var(--text-dim); border-color: var(--border); }

/* ===== カード ===== */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem 1.2rem;
  box-shadow: 0 .25rem .875rem rgba(0, 0, 0, .16);
}
.card h3 { margin-top: .2em; }
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(15.625rem, 1fr));
  gap: .9rem;
  padding: 0;
  list-style: none;
}
a.card-link {
  display: block;
  color: var(--text);
  text-decoration: none;
  transition: transform 240ms ease-out, opacity 240ms ease-out;
}
a.card-link:hover { background: var(--surface-hover); transform: translateY(-.125rem); text-decoration: none; }
a.card-link .card-title { font-weight: 800; line-height: 1.15; letter-spacing: -.018em; color: var(--accent-soft); margin-bottom: .3em; }
a.card-link p { margin: 0; font-size: .88rem; color: var(--text-dim); }

/* ===== テーブル ===== */
.table-wrap { overflow-x: auto; margin: 1em 0; }
.data-table {
  border-collapse: collapse;
  width: 100%;
  font-size: .9rem;
  min-width: 35rem;
}
.data-table th, .data-table td {
  border: 1px solid var(--border);
  padding: .5em .7em;
  text-align: left;
  vertical-align: top;
}
.data-table th { background: var(--bg-alt); color: var(--accent-soft); white-space: nowrap; }
.data-table tbody tr:nth-child(odd) { background: rgba(255,255,255,.02); }
.data-table tbody tr:hover { background: var(--surface-hover); }

/* ===== 検索・フィルタUI ===== */
.toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: .6rem;
  align-items: center;
  margin: 1rem 0;
}
input[type="search"], .search-box {
  background: var(--pit-black);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: .5rem;
  padding: .5em .9em;
  font-size: .95rem;
  min-width: 14.375rem;
}
input[type="search"]:focus { outline: .125rem solid var(--accent); border-color: var(--accent); }
.filter-btns { display: flex; flex-wrap: wrap; gap: .35rem; }
.filter-btn {
  background: var(--pit-black);
  color: var(--text-dim);
  border: 1px solid var(--border);
  border-radius: 999rem;
  padding: .3em .95em;
  font-size: .82rem;
  font-weight: 700;
  cursor: pointer;
  transition: transform 240ms ease-out, opacity 240ms ease-out;
}
.filter-btn:hover { color: var(--text); background: var(--surface-hover); }
.filter-btn.active { background: var(--accent); border-color: var(--accent); color: #fff; }
.result-count { color: var(--text-dim); font-size: .85rem; margin-left: auto; }

/* ===== SVGホットスポット ===== */
.hotspot {
  cursor: pointer;
  transform-box: fill-box;
  transform-origin: center;
  transition: transform 240ms ease-out, opacity 240ms ease-out;
}
.hotspot circle.hs-dot {
  fill: var(--accent);
  stroke: #fff;
  stroke-width: .09375rem;
}
.hotspot:hover circle.hs-dot,
.hotspot:focus circle.hs-dot { fill: var(--gold); }
.hotspot:focus { outline: none; }
.hotspot:focus circle.hs-dot { stroke: var(--gold); stroke-width: .1875rem; }
.hotspot.selected circle.hs-dot { fill: var(--gold); }
.hotspot text { fill: var(--text); font-size: .6875rem; font-weight: 700; pointer-events: none; }

/* ===== 汎用 ===== */
.lead { font-size: 1.03rem; color: var(--text-dim); }
.note {
  background: var(--bg-alt);
  border-left: .25rem solid var(--gold);
  padding: .7em 1em;
  border-radius: 0 .5rem .5rem 0;
  font-size: .9rem;
  margin: 1em 0;
}
.sources {
  margin-top: 3rem;
  padding-top: 1rem;
  border-top: .125rem dashed var(--border);
  font-size: .88rem;
  color: var(--text-dim);
}
.sources h2 { border-left-color: var(--gold); }
.kv { color: var(--gold); font-weight: 700; }
.svg-figure { margin: 1.2rem 0; text-align: center; }
.svg-figure svg { max-width: 100%; height: auto; }
.svg-figure figcaption { color: var(--text-dim); font-size: .84rem; margin-top: .4rem; }
details.qa-item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin: .6rem 0;
  padding: .2rem 1rem;
}
details.qa-item summary {
  cursor: pointer;
  font-weight: 700;
  padding: .55em 0;
  color: var(--accent-soft);
  transition: transform 240ms ease-out, opacity 240ms ease-out;
}
details.qa-item[open] summary { border-bottom: 1px solid var(--border); }

/* タッチでも即座に操作を返す。色の変化は状態表現、動きは transform / opacity のみに限定。 */
.card-link:active,
a.card-link:active,
.filter-btn:active,
.hotspot:active,
.pitboard-nav a:active,
details.qa-item summary:active {
  transform: scale(.97);
  transition: transform 100ms ease-out;
}

.card-link:focus-visible,
.filter-btn:focus-visible,
.pitboard-nav a:focus-visible,
details.qa-item summary:focus-visible {
  outline: .125rem solid var(--accent-soft);
  outline-offset: .125rem;
}

@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; }
  html { scroll-behavior: auto; }
  .card-link, .filter-btn, .hotspot, .pitboard-nav a, details.qa-item summary { transition: opacity 160ms ease !important; transform: none !important; }
}

@media (prefers-reduced-transparency: reduce) {
  .site-header { background: var(--bg-alt); -webkit-backdrop-filter: none; backdrop-filter: none; }
}

@media (prefers-contrast: more) {
  .card, .data-table th, .data-table td, .filter-btn, input[type="search"] { border-color: #6b7699; }
}

@media (max-width: 40rem) {
  body { font-size: .9375rem; }
  .pitboard-nav a { font-size: .78rem; padding: .4em .6em; }
  .data-table { min-width: 30rem; }
}