/* ============================================================
   CASE STUDY — image-forward layout
   Modeled on the reference structure: hero collage card, title
   below, labeled meta grid, sticky section TOC, eyebrow'd
   sections, before/after figure pairs with captions, a giant
   impact statement, and numbered research insights.
   ============================================================ */

.cs2 {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 var(--pad-x);
}

/* ── hero: collage card, then title ─────────────────────── */

.cs2-hero { padding-top: clamp(6.5rem, 14vh, 9rem); }

.cs2-hero-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 22px;
  padding: clamp(1rem, 3vw, 2.6rem);
}

.cs2-hero-card img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 12px;
}

.cs2-title-row { padding: clamp(1.6rem, 3.4vh, 2.6rem) 0.25rem 0; }

.cs2-title {
  font-family: var(--font-display);
  font-weight: 500;
  font-size: clamp(2rem, 4.6vw, 3.4rem);
  line-height: 1.05;
  color: var(--ink);
}

.cs2-sub {
  font-family: var(--font-ui);
  font-weight: 300;
  font-size: clamp(1rem, 1.9vh, 1.15rem);
  color: var(--ink-2);
  margin-top: 0.6rem;
  max-width: 46em;
}

/* ── meta grid ──────────────────────────────────────────── */

.cs2-meta {
  display: grid;
  grid-template-columns: minmax(280px, 1.6fr) repeat(3, minmax(140px, 1fr));
  gap: clamp(1.4rem, 3vw, 3rem);
  padding: clamp(1.8rem, 4vh, 3rem) 0.25rem clamp(2.6rem, 6vh, 4.5rem);
  border-bottom: 1px solid var(--border);
}

.cs2-meta .k {
  display: block;
  font-family: var(--font-ui);
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.65rem;
}

.cs2-meta .v {
  font-family: var(--font-ui);
  font-weight: 300;
  font-size: 0.92rem;
  line-height: 1.65;
  color: var(--ink);
}

/* ── body: sticky toc + content ─────────────────────────── */

.cs2-body {
  display: grid;
  grid-template-columns: 180px minmax(0, 1fr);
  gap: clamp(2rem, 5vw, 5rem);
  padding-top: clamp(2.6rem, 6vh, 4.5rem);
}

.cs2-toc {
  position: sticky;
  top: 110px;
  align-self: start;
  font-family: var(--font-ui);
  font-size: 0.8rem;
  line-height: 2.2;
}

.cs2-toc a {
  display: block;
  color: var(--ink-2);
  text-decoration: none;
  border-left: 2px solid transparent;
  padding-left: 12px;
  transition: color 0.2s, border-color 0.2s;
}

.cs2-toc a:hover, .cs2-toc a.on { color: var(--accent); border-left-color: var(--accent); }

/* ── sections ───────────────────────────────────────────── */

.cs2-section { margin-bottom: clamp(4.5rem, 11vh, 8rem); scroll-margin-top: 110px; }

.cs2-eyebrow {
  display: block;
  font-family: var(--font-ui);
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 1rem;
}

.cs2-h {
  font-family: var(--font-display);
  font-weight: 500;
  font-size: clamp(1.5rem, 3vw, 2.3rem);
  line-height: 1.12;
  color: var(--ink);
  max-width: 24em;
  margin-bottom: 1.1rem;
}

.cs2-h--accent {
  color: var(--accent);
  font-style: italic;
  font-size: clamp(1.7rem, 3.6vw, 2.8rem);
  max-width: 21em;
}

.cs2-p {
  font-family: var(--font-ui);
  font-weight: 300;
  font-size: clamp(0.98rem, 1.9vh, 1.08rem);
  line-height: 1.75;
  color: #45423a;
  max-width: 42em;
  margin-bottom: 1rem;
}

/* who-for columns */
.cs2-cols {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.5rem;
  margin-top: 2rem;
}

.cs2-col {
  border-left: 2px solid var(--border);
  padding-left: 1.25rem;
}

.cs2-col h4 {
  font-family: var(--font-ui);
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--ink);
  margin-bottom: 0.5rem;
}

.cs2-col p {
  font-family: var(--font-ui);
  font-weight: 300;
  font-size: 0.9rem;
  line-height: 1.7;
  color: var(--ink-2);
}

/* prototype-style CTA */
.cs2-cta {
  display: inline-block;
  font-family: var(--font-ui);
  font-size: 0.85rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  color: var(--accent);
  border: 1.5px solid var(--accent);
  border-radius: 8px;
  padding: 0.8rem 1.6rem;
  text-decoration: none;
  margin: 0.4rem 0 1rem;
  transition: background 0.2s, color 0.2s;
}

.cs2-cta:hover { background: var(--accent); color: #fff; }

/* ── solution blocks + figures ──────────────────────────── */

.cs2-block { margin: clamp(2.8rem, 6vh, 4.5rem) 0; }

.cs2-block-h {
  font-family: var(--font-ui);
  font-size: clamp(1.05rem, 2.1vh, 1.25rem);
  font-weight: 600;
  color: var(--ink);
  margin-bottom: 1.2rem;
}

.cs2-ba {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: clamp(1rem, 2.4vw, 2rem);
  align-items: start;
}

.cs2-shot { margin: 0; }

.cs2-shot .frame {
  position: relative;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: clamp(0.6rem, 1.4vw, 1.1rem);
}

.cs2-shot img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 8px;
}

.cs2-shot .tag {
  position: absolute;
  top: -12px;
  left: 18px;
  font-family: var(--font-ui);
  font-size: 0.68rem;
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  padding: 4px 12px;
  border-radius: 999px;
}

.cs2-shot .tag--before { background: #dcd9d1; color: #57544c; }
.cs2-shot .tag--after { background: var(--accent); color: #fff; }

.cs2-shot figcaption,
.cs2-fig figcaption {
  font-family: var(--font-ui);
  font-weight: 300;
  font-size: 0.85rem;
  line-height: 1.6;
  color: var(--ink-2);
  padding: 0.8rem 0.3rem 0;
  max-width: 40em;
}

.cs2-fig { margin: 1.6rem 0 0; }

.cs2-fig .frame {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: clamp(0.6rem, 1.4vw, 1.1rem);
}

.cs2-fig img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 8px;
}

/* ── impact ─────────────────────────────────────────────── */

.cs2-impact-h {
  font-family: var(--font-display);
  font-weight: 500;
  font-size: clamp(1.8rem, 4vw, 3rem);
  line-height: 1.12;
  color: var(--ink);
  max-width: 20em;
  margin-bottom: 1.4rem;
}

.cs2-impact-h em { font-style: italic; color: var(--accent); }

.cs2-stats {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
  margin: 1.4rem 0 0.6rem;
}

.cs2-stat {
  font-family: var(--font-ui);
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--ink);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 0.55rem 1.1rem;
}

.cs2-stat b { color: var(--accent); font-weight: 700; }

/* ── numbered insights ──────────────────────────────────── */

.cs2-insights {
  counter-reset: ins;
  list-style: none;
  margin-top: 1.6rem;
  display: grid;
  gap: 1rem;
}

.cs2-insights li {
  counter-increment: ins;
  position: relative;
  border: 1px solid var(--border);
  border-radius: 14px;
  background: #fff;
  padding: 1.3rem 1.5rem 1.3rem 4.4rem;
  font-family: var(--font-ui);
}

.cs2-insights li::before {
  content: counter(ins);
  position: absolute;
  left: 1.4rem;
  top: 1.15rem;
  width: 2rem;
  height: 2rem;
  border-radius: 50%;
  background: var(--accent);
  color: #fff;
  font-weight: 700;
  font-size: 0.95rem;
  display: flex;
  align-items: center;
  justify-content: center;
}

.cs2-insights h4 { font-size: 0.98rem; font-weight: 600; color: var(--ink); margin-bottom: 0.35rem; }
.cs2-insights p { font-size: 0.88rem; font-weight: 300; line-height: 1.65; color: var(--ink-2); }

/* ── next-project footer ────────────────────────────────── */

.cs2-next {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  border-top: 1px solid var(--border);
  margin-top: clamp(2rem, 5vh, 4rem);
  padding: clamp(1.8rem, 4vh, 3rem) 0 clamp(3rem, 7vh, 5rem);
  font-family: var(--font-ui);
}

.cs2-next a {
  color: var(--ink);
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 500;
}

.cs2-next a span { display: block; font-size: 0.72rem; font-weight: 600; letter-spacing: 0.18em; text-transform: uppercase; color: var(--accent); margin-bottom: 0.4rem; }
.cs2-next a:hover { color: var(--accent); }

/* ── responsive ─────────────────────────────────────────── */

@media (max-width: 1000px) {
  .cs2-body { grid-template-columns: 1fr; }
  .cs2-toc { display: none; }
  .cs2-meta { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 640px) {
  .cs2-ba { grid-template-columns: 1fr; }
  .cs2-meta { grid-template-columns: 1fr; gap: 1.2rem; }
}