body { display: flex; flex-direction: column; min-height: 100vh; }
main { flex: 1; padding-top: calc(var(--nav-h) + 56px); padding-bottom: 96px; }

.pd-breadcrumb {
  font-family: var(--font-mono);
  font-size: var(--fs-2xs);
  color: var(--text-2);
  letter-spacing: var(--ls-normal);
  margin-bottom: 22px;
}

.pd-breadcrumb a {
  color: var(--text-2);
  transition: color var(--t);
}

.pd-breadcrumb a:hover {
  color: var(--accent-blue);
}

.pd-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 18px;
  margin-bottom: 20px;
}

.pd-title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(2rem, 5vw, 3.2rem);
  letter-spacing: -0.02em;
}

.pd-status-pill {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: var(--ls-wide);
  text-transform: uppercase;
  padding: 8px 16px;
  border-radius: 99px;
  border: 1px solid var(--border-m);
  flex-shrink: 0;
  margin-top: 8px;
}

.pd-status-pill::before {
  content: "";
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: currentColor;
}

.pd-desc {
  color: var(--text-1);
  font-size: var(--fs-md);
  line-height: 1.9;
  max-width: 680px;
  margin-bottom: 20px;
}

.pd-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 48px;
}

.pd-meta-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 14px;
  margin-bottom: 48px;
}

.pd-meta-item {
  padding: 18px 20px;
  border-radius: var(--r-md);
  border: 1px solid var(--border);
  background: var(--bg-card);
}

.pd-meta-label {
  font-family: var(--font-mono);
  font-size: var(--fs-2xs);
  color: var(--text-2);
  letter-spacing: var(--ls-wide);
  text-transform: uppercase;
  margin-bottom: 8px;
}

.pd-meta-value {
  color: var(--text-0);
  font-size: var(--fs-base);
  font-weight: 500;
}

.pd-section {
  margin-bottom: 48px;
}

.pd-section-title {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  color: var(--accent-teal);
  letter-spacing: var(--ls-label);
  text-transform: uppercase;
  margin-bottom: 18px;
}

.pd-long-desc {
  color: var(--text-1);
  font-size: var(--fs-base);
  line-height: 1.9;
  max-width: 720px;
}

.pd-tech-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.pd-tech-tag {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  color: var(--text-1);
  padding: 7px 15px;
  border: 1px solid var(--border-m);
  border-radius: 99px;
}

.pd-back {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  color: var(--text-1);
  letter-spacing: var(--ls-normal);
  padding: 10px 6px;
  transition: color var(--t);
}

.pd-back:hover {
  color: var(--accent-blue);
}

.pd-back svg {
  width: 16px;
  height: 16px;
}

/* ── 関連Research/Notes(要件10: Related Notes / Related Research) ── */
.pd-related-list {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.pd-related-list li {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding: 13px 0;
  border-top: 1px solid var(--border);
}

.pd-related-list li:first-child { border-top: none; }

.pd-related-list a {
  color: var(--text-0);
  font-size: var(--fs-sm);
  transition: color var(--t);
}

.pd-related-list a:hover { color: var(--accent-blue); }

.pd-related-summary {
  flex-shrink: 0;
  font-family: var(--font-mono);
  font-size: var(--fs-2xs);
  color: var(--text-2);
  max-width: 45%;
  text-align: right;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}