/* ============================================
   KEEL — Case study page
   Reuses tokens + components from styles.css
   (immersive diff blocks follow the documented
   always-dark surface pattern from the audit)
   ============================================ */

.case {
  max-width: 76ch;
  margin: 0 auto;
  padding: 0 24px 96px;
}

/* ---- hero ---- */
.case-hero { padding: 64px 0 8px; }
.case-hero .label { display: block; margin-bottom: 1rem; }
.case-hero h1 {
  font-size: clamp(2.1rem, 5vw, 3.3rem);
  font-weight: 900;
  letter-spacing: -0.03em;
  line-height: 1.06;
  margin-bottom: 1.25rem;
  color: var(--text-primary);
}
.case-hero .lede {
  font-size: 1.06rem;
  line-height: 1.65;
  color: var(--text-secondary);
  max-width: 62ch;
}
.case-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.75rem;
  margin-top: 2rem;
  padding: 0.9rem 1.15rem;
  border: 1px solid var(--border-cell);
  border-radius: 12px;
  background: var(--bg-cell-alt);
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.72rem;
  color: var(--text-secondary);
}
.case-meta strong { color: var(--text-primary); font-weight: 700; }

/* ---- pipeline diagram ---- */
.case-flow {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
  margin: 44px 0 8px;
}
.flow-node {
  position: relative;
  background: var(--bg-cell);
  border: 1px solid var(--border-cell);
  border-radius: 14px;
  padding: 1rem 1.1rem;
}
.flow-node--live { border-color: var(--accent); box-shadow: 0 0 0 1px var(--accent) inset; }
.flow-node__step {
  display: block;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  color: var(--text-muted);
  margin-bottom: 0.5rem;
}
.flow-node__name {
  display: block;
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.35rem;
}
.flow-node__desc {
  font-size: 0.78rem;
  line-height: 1.5;
  color: var(--text-secondary);
}
.flow-node:not(:last-child)::after {
  content: '→';
  position: absolute;
  right: -13px;
  top: 50%;
  transform: translateY(-50%);
  z-index: 1;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* ---- sections ---- */
.case-sec { margin-top: 56px; }
.case-sec__eyebrow {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  color: var(--accent);
  margin-bottom: 0.6rem;
}
.case-sec h2 {
  font-size: 1.45rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 0.9rem;
  color: var(--text-primary);
}
.case-sec p {
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 0.9rem;
  max-width: 68ch;
}
.case-sec p strong { color: var(--text-primary); }

/* ---- directive quotes ---- */
.case-quote {
  border-left: 3px solid var(--accent);
  background: var(--bg-cell-alt);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  padding: 0.9rem 1.2rem;
  margin: 1.1rem 0;
}
.case-quote p {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
  margin: 0 0 0.3rem;
  max-width: none;
}
.case-quote cite {
  font-family: var(--font-mono);
  font-style: normal;
  font-size: 0.65rem;
  letter-spacing: 0.12em;
  color: var(--text-muted);
}

/* ---- stat strip ---- */
.case-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin: 2.2rem 0 0;
}
.case-stat {
  background: var(--bg-cell);
  border: 1px solid var(--border-cell);
  border-radius: var(--radius-md);
  padding: 1rem 1.1rem;
  box-shadow: var(--shadow-rest);
}
.case-stat__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text-primary);
}
.case-stat__num em { font-style: normal; color: var(--accent); }
.case-stat__label {
  display: block;
  font-size: 0.7rem;
  color: var(--text-muted);
  margin-top: 0.25rem;
}

/* ---- lists ---- */
.case-list { list-style: none; margin: 0.5rem 0 0; display: grid; gap: 0.65rem; }
.case-list li {
  position: relative;
  padding-left: 1.4rem;
  color: var(--text-secondary);
  line-height: 1.6;
  font-size: 0.95rem;
}
.case-list li::before {
  content: '▸';
  position: absolute;
  left: 0;
  top: 0;
  color: var(--accent);
  font-family: var(--font-mono);
}
.case-list li strong { color: var(--text-primary); }

/* ---- bug story cards ---- */
.case-bug {
  border: 1px solid var(--border-cell);
  border-radius: var(--radius-md);
  background: var(--bg-cell);
  box-shadow: var(--shadow-rest);
  padding: 1.2rem 1.3rem;
  margin-top: 1rem;
}
.case-bug__tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  padding: 0.2rem 0.55rem;
  border-radius: 999px;
  background: var(--alert-soft);
  color: var(--alert);
  margin-bottom: 0.7rem;
}
.case-bug h3 {
  font-size: 1.02rem;
  font-weight: 700;
  margin-bottom: 0.45rem;
  color: var(--text-primary);
}
.case-bug p { font-size: 0.9rem; margin-bottom: 0.7rem; }
.case-bug code, .case-sec code {
  font-family: var(--font-mono);
  font-size: 0.85em;
  background: var(--bg-cell-alt);
  border: 1px solid var(--border-cell);
  border-radius: 4px;
  padding: 0.08em 0.35em;
}
/* code diffs: always-dark immersive surface (documented pattern) */
.case-code {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  line-height: 1.65;
  background: var(--bg-immersive);
  color: #E9EDF4;
  border-radius: var(--radius-sm);
  padding: 0.85rem 1rem;
  overflow-x: auto;
  white-space: pre;
}
.case-code .del { color: #F87171; }
.case-code .add { color: #34D399; }
.case-code .cmt { color: #7C879B; }

/* ---- footer ---- */
.case-foot {
  margin-top: 72px;
  padding-top: 1.4rem;
  border-top: 1px solid var(--border-cell);
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1.5rem;
  align-items: center;
  justify-content: space-between;
}
.case-foot .mono {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-muted);
}
.case-foot nav { display: flex; gap: 1.25rem; }

/* ---- responsive ---- */
@media (max-width: 720px) {
  .case { padding: 0 16px 72px; }
  .case-hero { padding-top: 44px; }
  .case-flow { grid-template-columns: 1fr 1fr; margin-top: 32px; }
  .flow-node:not(:last-child)::after { content: none; }
  .case-stats { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 460px) {
  .case-flow { grid-template-columns: 1fr; }
  .case-stats { grid-template-columns: 1fr; }
}