/* ============================================================
   CASE STUDY PAGE
   ============================================================ */

/* ── Hero ───────────────────────────────────────────────── */
.cs-hero {
  padding-top: calc(var(--space-16) + 80px);
  padding-bottom: var(--space-12);
}

.cs-hero__inner {
  max-width: 900px;
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.cs-hero__meta {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.cs-hero__client {
  font-size: var(--text-sm);
  font-weight: var(--weight-semibold);
  color: var(--color-text-muted);
}

.cs-hero__title { max-width: 760px; }
.cs-hero__sub { max-width: 640px; }

.cs-hero__details {
  display: flex;
  gap: var(--space-8);
  flex-wrap: wrap;
  padding-top: var(--space-4);
  border-top: 1px solid var(--color-border);
}

.cs-detail {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.cs-detail .label { margin: 0; }

.cs-detail__val {
  font-size: var(--text-base);
  font-weight: var(--weight-semibold);
  color: var(--color-text-primary);
}

/* Cover Image */
.cs-cover {
  margin-bottom: var(--space-12);
}

.cs-cover__img { width: 100%; overflow: hidden; }

/* ── Body Layout ─────────────────────────────────────────── */
.cs-body { padding: var(--space-12) 0 var(--space-20); }

.cs-body__inner {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: var(--space-12);
  align-items: start;
}

/* TOC */
.cs-toc {
  position: sticky;
  top: 100px;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.cs-toc .label { margin-bottom: var(--space-1); }

.cs-toc__nav {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.cs-toc__link {
  font-size: var(--text-sm);
  font-weight: var(--weight-medium);
  color: var(--color-text-muted);
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  border-left: 2px solid transparent;
  transition: all var(--dur-fast);
}

.cs-toc__link:hover,
.cs-toc__link.active {
  color: var(--color-accent);
  border-left-color: var(--color-accent);
  background: var(--color-accent-light);
}

/* Content */
.cs-content {
  display: flex;
  flex-direction: column;
  gap: var(--space-16);
}

.cs-section {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.cs-section__label {
  color: var(--color-accent);
  margin-bottom: 0;
}

/* Callout */
.cs-callout {
  border-left: 3px solid var(--color-accent);
  padding: var(--space-5) var(--space-6);
  background: var(--color-accent-light);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
}

.cs-callout__text {
  font-size: var(--text-xl);
  font-weight: var(--weight-medium);
  color: var(--color-text-primary);
  line-height: var(--leading-snug);
  font-style: italic;
}

/* Pillars */
.cs-pillars {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-3);
}

.cs-pillar {
  padding: var(--space-5);
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  transition: box-shadow var(--dur-base), transform var(--dur-base) var(--ease-out);
}

.cs-pillar:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-4px);
}

.cs-pillar__num {
  font-size: var(--text-xs);
  font-weight: var(--weight-black);
  color: var(--color-accent);
  letter-spacing: 0.1em;
}

.cs-pillar h3 {
  font-size: var(--text-base);
  font-weight: var(--weight-semibold);
  color: var(--color-text-primary);
}

.cs-pillar p {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: var(--leading-relaxed);
}

/* List */
.cs-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.cs-list li {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  padding-left: var(--space-4);
  position: relative;
  line-height: var(--leading-relaxed);
}

.cs-list li::before {
  content: '→';
  position: absolute;
  left: 0;
  color: var(--color-accent);
  font-size: 0.85em;
}

/* Results */
.cs-results {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-3);
}

.cs-result {
  padding: var(--space-6);
  background: var(--color-text-primary);
  color: var(--color-white);
  border-radius: var(--radius-lg);
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.cs-result__num {
  font-size: var(--text-4xl);
  font-weight: var(--weight-black);
  letter-spacing: -0.04em;
  line-height: 1;
  color: rgba(128, 127, 127, 0.623);
}

.cs-result__label {
  font-size: var(--text-sm);
  color: rgba(128, 127, 127, 0.623);
  font-weight: var(--weight-medium);
}

/* Image break */
.cs-img-break { width: 100%; overflow: hidden; }
.cs-img { width: 100%; }

/* Impact Grid */
.cs-impact-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-3);
}

.cs-impact-item {
  padding: var(--space-5);
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  transition: background var(--dur-base), transform var(--dur-base) var(--ease-out); 
}

.cs-impact-item:hover {
  background: var(--color-accent-light);
  transform: translateY(-4px);
}

.cs-impact-icon {
  font-size: 1.5rem;
  color: var(--color-accent);
}

.cs-impact-item h3 {
  font-size: var(--text-base);
  font-weight: var(--weight-semibold);
  color: var(--color-text-primary);
}

.cs-impact-item p {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: var(--leading-relaxed);
}

/* Takeaways */
.cs-takeaways {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.cs-takeaway {
  display: grid;
  grid-template-columns: 48px 1fr;
  gap: var(--space-4);
  align-items: start;
  padding: var(--space-5);
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  transition: background var(--dur-base), transform var(--dur-base) var(--ease-out); 
}

.cs-takeaway:hover {
  background: var(--color-accent-light);
  transform: translateX(8px);
}

.cs-takeaway__num {
  font-size: var(--text-2xl);
  font-weight: var(--weight-black);
  color: var(--color-accent);
  letter-spacing: -0.04em;
  line-height: 1;
}

.cs-takeaway h3 {
  font-size: var(--text-base);
  font-weight: var(--weight-semibold);
  color: var(--color-text-primary);
  margin-bottom: 4px;
}

.cs-takeaway p {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: var(--leading-relaxed);
}

/* ── Next Project ─────────────────────────────────────────── */
.cs-next {
  padding: var(--space-16) 0;
  border-top: 1px solid var(--color-border);
}

.cs-next__inner {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.cs-next__inner .label { color: var(--color-text-muted); }

.cs-next__link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  text-decoration: none;
  color: var(--color-text-primary);
  transition: color var(--dur-base);
}

.cs-next__link:hover { color: var(--color-accent); }

.cs-next__link .display-md {
  font-size: clamp(2rem, 4vw, 3.5rem);
  transition: transform var(--dur-base) var(--ease-out);
}

.cs-next__link:hover .display-md { transform: translateX(8px); }

.cs-next__arrow {
  font-size: 4rem;
  line-height: 1;
  transition: transform var(--dur-base) var(--ease-out);
}

.cs-next__link:hover .cs-next__arrow { transform: translateX(16px) translateY(-8px); }

/* ── Responsive ─────────────────────────────────────────── */
@media (max-width: 900px) {
  .cs-body__inner { grid-template-columns: 1fr; }
  .cs-toc { display: none; }
  .cs-pillars { grid-template-columns: 1fr; }
  .cs-results { grid-template-columns: 1fr; }
  .cs-impact-grid { grid-template-columns: 1fr; }
}

@media (max-width: 768px) {
  .cs-hero__details { gap: var(--space-4); }
}