:root {
  --ink: #111827;
  --gray: #6b7280;
  --line: #e5e7eb;
  --accent: #f97316;
  --accent2: #ea580c;
  --paper: #fff;
  --bg: #f9fafb;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

body {
  font-family: "Noto Sans JP", sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.8;
}

a { color: inherit; text-decoration: none; }

.parts-header {
  background: var(--ink);
  color: #fff;
  padding: 48px 20px;
  border-bottom: 4px solid var(--accent);
}

.parts-header-inner {
  max-width: 960px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 24px;
  flex-wrap: wrap;
}

.parts-en {
  font-family: "Manrope", sans-serif;
  font-size: 12px;
  letter-spacing: .24em;
  color: var(--accent);
  margin-bottom: 8px;
}

.parts-header h1 {
  font-size: clamp(28px, 5vw, 36px);
  font-weight: 900;
  margin-bottom: 10px;
}

.parts-lead {
  color: rgba(255,255,255,.7);
  font-size: 14px;
  max-width: 520px;
}

.parts-back {
  display: inline-flex;
  align-items: center;
  padding: 10px 18px;
  border: 1px solid rgba(255,255,255,.25);
  border-radius: 999px;
  font-size: 13px;
  font-weight: 700;
  white-space: nowrap;
}

.parts-back:hover { background: rgba(255,255,255,.08); }

.parts-main {
  max-width: 960px;
  margin: 0 auto;
  padding: 40px 20px 64px;
}

.parts-grid {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
}

.parts-card {
  display: flex;
  flex-direction: column;
  gap: 10px;
  background: var(--paper);
  border: 2px solid var(--ink);
  padding: 24px;
  min-height: 220px;
  box-shadow: 6px 6px 0 var(--ink);
  transition: transform .2s ease, box-shadow .2s ease;
}

.parts-card:hover {
  transform: translate(-3px, -3px);
  box-shadow: 9px 9px 0 var(--ink);
}

.parts-card-tag {
  align-self: flex-start;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .06em;
  color: var(--accent2);
  background: #fff7ed;
  padding: 4px 10px;
  border-radius: 999px;
}

.parts-card h2 {
  font-size: 20px;
  font-weight: 800;
}

.parts-card p {
  flex: 1;
  font-size: 14px;
  color: var(--gray);
}

.parts-card-link {
  font-size: 14px;
  font-weight: 700;
  color: var(--accent2);
}

.parts-footer {
  text-align: center;
  padding: 24px;
  font-size: 12px;
  color: var(--gray);
  border-top: 1px solid var(--line);
}