/* ─────────────────────────────────────────
   CASE STUDY — UTILITY NETWORKS
───────────────────────────────────────── */

/* Back link */
.cs-back-link {
  position: fixed;
  left: 5vw;
  top: 78px;
  font-family: var(--font-sans);
  font-size: 13px;
  font-weight: 500;
  color: var(--black);
  z-index: 500;
  transition: opacity 0.2s;
}
.cs-back-link:hover { opacity: 0.45; }

/* ── Main wrapper ── */
.cs-main {
  padding-top: 100px;
  padding-left: 20vw;
  padding-right: 20vw;
  padding-bottom: 140px;
}

/* ── Shared section spacing ── */
.cs-section { margin-bottom: 120px; }

/* ── Tag / label ── */
.cs-tag {
  font-family: var(--font-sans);
  font-size: 12px;
  font-weight: 500;
  color: var(--muted);
  letter-spacing: 0.07em;
  text-transform: uppercase;
  margin-bottom: 28px;
}

/* ── Hero title ── */
.cs-title {
  font-family: var(--font-serif);
  font-size: 68px;
  font-weight: 300;
  line-height: 1.08;
  color: var(--black);
  margin-bottom: 28px;
}

/* ── Subtitle ── */
.cs-subtitle {
  font-family: var(--font-body);
  font-size: 17px;
  font-weight: 400;
  color: var(--black);
  line-height: 1.6;
  margin-bottom: 20px;
}

/* ── Body text ── */
.cs-body {
  font-family: var(--font-body);
  font-size: 17px;
  font-weight: 500;
  color: var(--black);
  line-height: 28px;
  letter-spacing: 0.4px;
}
.cs-body + .cs-body { margin-top: 16px; }
.cs-body--mt { margin-top: 20px; }

/* ── Hero layout ── */
.cs-hero { margin-bottom: 120px; }

.cs-hero-inner {
  display: flex;
  gap: 48px;
  align-items: flex-start;
  margin-bottom: 56px;
}

.cs-hero-left { flex: 1; }

/* ── Results card ── */
.cs-results-card {
  flex: 0 0 220px;
  background: #f0f2f0;
  border-radius: 14px;
  padding: 28px 28px 28px;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.cs-results-label {
  font-family: var(--font-sans);
  font-size: 11px;
  font-weight: 500;
  color: var(--muted);
  letter-spacing: 0.07em;
  text-transform: uppercase;
}

.cs-result-num {
  font-family: var(--font-sans);
  font-size: 42px;
  font-weight: 700;
  color: var(--black);
  line-height: 1;
  margin-bottom: 6px;
}

.cs-result-desc {
  font-family: var(--font-body);
  font-size: 13px;
  color: var(--black);
  line-height: 1.5;
}

/* ── Video section ── */
.cs-video-wrap {
  width: 100%;
  overflow: hidden;
  position: relative;
  margin-bottom: 0;
}

.cs-video {
  width: 100%;
  height: auto;
  display: block;
}

/* ── Meta section ── */
.cs-meta {
  margin-bottom: 100px;
  padding-bottom: 60px;
  border-bottom: 1px solid #e8e8e8;
}

.cs-meta-rows {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.cs-meta-row {
  display: flex;
  align-items: center;
  padding: 20px 0;
  border-bottom: 1px solid #f0f0f0;
  gap: 0;
}

.cs-meta-row:first-child { border-top: 1px solid #f0f0f0; }

.cs-meta-label {
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 400;
  color: var(--black);
  flex: 0 0 180px;
  min-width: 180px;
}

.cs-meta-tags { display: flex; flex-wrap: wrap; gap: 8px; }

.cs-meta-tag {
  font-family: var(--font-body);
  font-size: 13px;
  color: var(--black);
  border: 1px solid #c8c8c8;
  border-radius: 100px;
  padding: 6px 16px;
}

/* ── Section heading ── */
.cs-section-title {
  font-family: var(--font-serif);
  font-size: 52px;
  font-weight: 300;
  color: var(--black);
  line-height: 1.1;
  margin-bottom: 48px;
}

.cs-section-title--sm {
  font-size: 36px;
}

.cs-title-accent { color: var(--muted); }

.cs-sub-heading {
  font-family: var(--font-serif);
  font-size: 22px;
  font-weight: 300;
  color: var(--black);
  margin-bottom: 32px;
}

/* ── Design blocks ── */
.cs-design-block { margin-bottom: 88px; }
.cs-design-block:last-child { margin-bottom: 0; }

.cs-design-text {
  display: flex;
  gap: 40px;
  align-items: flex-start;
  margin-bottom: 36px;
}

.cs-design-heading {
  font-family: var(--font-serif);
  font-size: 30px;
  font-weight: 300;
  color: var(--black);
  flex: 0 0 44%;
  line-height: 1.2;
}

.cs-design-desc {
  font-family: var(--font-body);
  font-size: 17px;
  font-weight: 500;
  color: var(--black);
  line-height: 28px;
  letter-spacing: 0.4px;
  flex: 1;
}

.cs-design-img {
  width: 100%;
  height: auto;
  border-radius: 16px;
  display: block;
}

/* Select Target Assets: reversed side-by-side layout */
.cs-design-block--side {
  display: flex;
  gap: 40px;
  align-items: flex-start;
  margin-bottom: 0;
}

.cs-design-img-left {
  flex: 0 0 66%;
  width: 66%;
  height: auto;
  border-radius: 16px;
  display: block;
}

.cs-design-text-right {
  flex: 1;
  padding-top: 8px;
}

/* ── Two-column text ── */
.cs-two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  margin-bottom: 40px;
}

/* ── Principles section ── */
.cs-principles-row {
  display: flex;
  gap: 40px;
  margin-bottom: 48px;
  align-items: flex-start;
}

.cs-principles-left { flex: 0 0 42%; }
.cs-principles-right { flex: 1; }

.cs-principles-row .cs-bullet-heading {
  flex: 0 0 42%;
  margin-bottom: 0;
}

.cs-bullet-heading {
  font-family: var(--font-serif);
  font-size: 22px;
  font-weight: 300;
  color: var(--black);
  margin-bottom: 16px;
}

/* ── Key considerations cards ── */
.cs-cards {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.cs-card {
  background: #f5f5f3;
  border-radius: 12px;
  padding: 24px 24px;
  display: flex;
  align-items: flex-start;
  gap: 16px;
}

.cs-card-icon {
  width: 30px;
  height: 30px;
  flex-shrink: 0;
  object-fit: contain;
}

.cs-card-text {
  font-family: var(--font-body);
  font-size: 15px;
  color: var(--black);
  line-height: 1.55;
}

/* ── Full-width image ── */
.cs-full-img {
  width: 100%;
  height: auto;
  display: block;
  border-radius: 12px;
}

/* ── Audit annotations ── */
.cs-audit-annotations {
  display: flex;
  gap: 32px;
  margin-top: 32px;
}

.cs-annotation { flex: 1; }

.cs-annotation-title {
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 600;
  color: var(--black);
  margin-bottom: 6px;
}

.cs-annotation-desc {
  font-family: var(--font-body);
  font-size: 13px;
  color: var(--muted);
  line-height: 1.55;
}

/* ── Table (Insights / Real-World Constraints) ── */
.cs-table { border-top: 1px solid #e8e8e8; }

.cs-table-header {
  display: grid;
  grid-template-columns: 52px 1fr 1fr;
  gap: 32px;
  padding: 14px 0;
  border-bottom: 1px solid #e8e8e8;
}

.cs-table-header-spacer { /* empty first cell */ }

.cs-table-col-label {
  font-family: var(--font-sans);
  font-size: 11px;
  font-weight: 500;
  color: var(--muted);
  letter-spacing: 0.07em;
  text-transform: uppercase;
}

.cs-table-row {
  display: grid;
  grid-template-columns: 52px 1fr 1fr;
  gap: 32px;
  padding: 28px 0;
  border-bottom: 1px solid #e8e8e8;
  align-items: start;
}

.cs-table-num {
  font-family: var(--font-sans);
  font-size: 13px;
  font-weight: 700;
  color: #4545ff;
  padding-top: 2px;
}

.cs-table-finding,
.cs-table-decision {
  font-family: var(--font-body);
  font-size: 16px;
  color: var(--black);
  line-height: 1.65;
}

/* ── Exploration / Research rows ── */
.cs-two-text-row {
  display: flex;
  gap: 40px;
  margin-bottom: 40px;
  align-items: flex-start;
}

.cs-two-text-row .cs-bullet-heading {
  flex: 0 0 42%;
  margin-bottom: 0;
}

/* ── Quotes image ── */
.cs-quotes-img {
  border-radius: 16px;
  width: 75%;
  margin-left: auto;
  margin-right: auto;
}

/* ── Usability improvements ── */
.cs-improvement { margin-bottom: 88px; }
.cs-improvement:last-child { margin-bottom: 0; }

.cs-improvement .cs-body { margin-top: 16px; }

.cs-before-after {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  margin-top: 40px;
}

.cs-ba-col {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.cs-ba-label {
  display: inline-block;
  font-family: var(--font-sans);
  font-size: 13px;
  font-weight: 500;
  color: var(--black);
  background: #ebebeb;
  border-radius: 100px;
  padding: 4px 18px;
  align-self: flex-start;
}

.cs-ba-img {
  width: 100%;
  height: auto;
  display: block;
  border-radius: 14px;
}

.cs-ba-bullets {
  border-radius: 10px;
  padding: 16px 18px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.cs-ba-bullets--before { background: #f0f0f0; }
.cs-ba-bullets--after  { background: #f0f0f0; }

.cs-ba-bullet {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-family: var(--font-body);
  font-size: 13px;
  color: var(--black);
  line-height: 1.55;
}

.cs-ba-bullet img {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
  margin-top: 2px;
  object-fit: contain;
}

/* ── Results section ── */
.cs-results-img { margin-top: 40px; }

/* ── CTO quote card ── */
.cs-cto-card {
  margin-top: 80px;
  display: flex;
  justify-content: center;
}

.cs-cto-img {
  width: 60%;
  height: auto;
  display: block;
}

/* ─────────────────────────────────────────
   RESPONSIVE
───────────────────────────────────────── */
@media (max-width: 1100px) {
  .cs-main { padding-left: 12vw; padding-right: 12vw; }
  .cs-title { font-size: 52px; }
}

@media (max-width: 900px) {
  .cs-main { padding-left: 6vw; padding-right: 6vw; }
  .cs-hero-inner { flex-direction: column; }
  .cs-results-card { flex: none; width: 100%; }
  .cs-two-col { grid-template-columns: 1fr; }
  .cs-cards { grid-template-columns: 1fr; }
  .cs-principles-row,
  .cs-two-text-row { flex-direction: column; }
  .cs-design-text { flex-direction: column; }
  .cs-before-after { grid-template-columns: 1fr; }
  .cs-audit-annotations { flex-direction: column; }
  .cs-back-link { left: 3vw; }
}