/* ============================================================
   CASE STUDY — extends styles.css
   ============================================================ */

/* ── Hero ───────────────────────────────────────────────── */
.cs-hero {
  padding-top:    calc(var(--nav-h) + 5rem);
  padding-bottom: 4rem;
}

.cs-back {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.7rem;
  font-weight: 500;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 3.5rem;
  transition: color 0.25s var(--ease);
}
.cs-back svg { transition: transform 0.25s var(--ease); }
.cs-back:hover { color: var(--text); }
.cs-back:hover svg { transform: translateX(-4px); }

.cs-hero__kicker {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  margin-bottom: 1.25rem;
  flex-wrap: wrap;
}

.cs-hero__date {
  font-size: 0.75rem;
  color: var(--muted);
  letter-spacing: 0.06em;
}

.cs-hero__title {
  font-family: var(--font-hero);
  font-weight: 700;
  font-size: clamp(5rem, 13vw, 13rem);
  letter-spacing: 0.06em;
  line-height: 0.9;
  color: var(--text);
}

/* ── Callout stats ──────────────────────────────────────── */
.cs-callout {
  margin-top: clamp(3rem, 6vw, 5rem);
  padding-top: clamp(2.5rem, 4vw, 3.5rem);
  border-top: 1px solid var(--border);
}

.cs-callout__grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.cs-callout__item {
  padding-inline: clamp(1.5rem, 3vw, 3rem);
  border-left: 1px solid var(--border);
  min-width: 0;
}

.cs-callout__item:first-child {
  padding-left: 0;
  border-left: none;
}

.cs-callout__num {
  display: block;
  font-family: var(--font-display);
  font-size: clamp(3.5rem, 8vw, 8rem);
  font-weight: 800;
  letter-spacing: -0.04em;
  line-height: 1;
  color: var(--text);
  margin-bottom: 0.875rem;
}

.cs-callout__num sup {
  font-size: 0.45em;
  vertical-align: super;
  letter-spacing: 0;
}

.cs-callout__label {
  font-size: 0.78rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
}

.cs-callout--compact .cs-callout__num {
  font-size: clamp(2rem, 4.5vw, 4rem);
}

.cs-callout__subtext {
  display: block;
  font-size: 0.72rem;
  color: var(--muted);
  letter-spacing: 0;
  text-transform: none;
  line-height: 1.5;
  margin-top: 0.375rem;
  max-width: 26ch;
}

.cs-hero__title--long {
  font-size: clamp(1.25rem, 6.5vw, 7rem);
  white-space: nowrap;
}

/* ── Insight pull quote ─────────────────────────────────── */
.cs-insight-pull {
  text-align: center;
  margin-top: 2rem;
  padding-block: 2rem;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.cs-insight-pull p {
  font-size: clamp(1.125rem, 2vw, 1.5rem);
  font-weight: 700;
  color: var(--text);
  line-height: 1.5;
  max-width: none;
}

.cs-insight-pull p + p {
  margin-top: 0.25rem;
}

/* ── Email collage ──────────────────────────────────────── */
.cs-email-collage {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.875rem;
  margin-top: 2.5rem;
  margin-bottom: 2.5rem;
}

.cs-email-collage__item {
  border-radius: 8px;
  overflow: hidden;
  border: 1px solid var(--border);
  box-shadow: 0 6px 24px rgba(0, 0, 0, 0.35);
}

.cs-email-collage__item img {
  width: 100%;
  display: block;
  height: 480px;
  object-fit: cover;
  object-position: top;
}

/* ── Live site button ───────────────────────────────────── */
.cs-livesite {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  font-size: 0.8125rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  color: var(--text);
  border: 1px solid var(--border);
  padding: 0.55rem 1.2rem;
  border-radius: 100px;
  margin-top: 1.75rem;
  transition: border-color 0.2s var(--ease), color 0.2s var(--ease);
}
.cs-livesite:hover {
  border-color: var(--muted);
  color: var(--accent);
}

/* ── Cover image ─────────────────────────────────────────── */
.cs-cover {
  padding-bottom: clamp(60px, 8vw, 100px);
}

.cs-cover__img {
  width: 100%;
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
}

.cs-cover__img img {
  width: 100%;
  display: block;
  object-fit: cover;
}

/* ── Inline body link ───────────────────────────────────── */
.cs-body-link {
  color: var(--text);
  border-bottom: 1px solid var(--border);
  padding-bottom: 1px;
  transition: border-color 0.2s var(--ease), color 0.2s var(--ease);
}
.cs-body-link:hover {
  border-color: var(--accent);
  color: var(--accent);
}

/* ── What We Built — two-column layout ──────────────────── */
.cs-built-cols {
  display: grid;
  grid-template-columns: 2fr 3fr;
  gap: 2rem;
  margin-top: 2.5rem;
  /* default align-items: stretch — image defines row height, matrix column fills to match */
}

.cs-built-col-img img {
  width: 100%;
  display: block;
  border-radius: 6px;
  border: 1px solid var(--border);
}

/* ── Competitive landscape matrix ───────────────────────── */
.cs-built-col-matrix {
  display: flex;
  flex-direction: column;
  gap: 0.625rem;
}

.cs-matrix {
  position: relative;
  flex: 1;          /* fill remaining column height after caption */
  min-height: 0;    /* allows flex item to shrink below content size */
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 6px;
  overflow: hidden;
}

.cs-matrix__vline {
  position: absolute;
  left: 50%;
  top: 10%;
  bottom: 10%;
  width: 1px;
  background: rgba(237, 233, 223, 0.22);
}

.cs-matrix__hline {
  position: absolute;
  top: 50%;
  left: 10%;
  right: 10%;
  height: 1px;
  background: rgba(237, 233, 223, 0.22);
}

.cs-matrix__axis {
  position: absolute;
  font-size: 0.57rem;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  color: var(--text);
  line-height: 1;
  pointer-events: none;
}

.cs-matrix__axis--top    { top: 3.5%; left: 50%; transform: translateX(-50%); }
.cs-matrix__axis--bottom { bottom: 3.5%; left: 50%; transform: translateX(-50%); }
.cs-matrix__axis--left   { top: 53%; left: 5%; }
.cs-matrix__axis--right  { top: 53%; right: 5%; }

.cs-matrix__dot {
  position: absolute;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 5px;
  transform: translate(-50%, -50%);
  pointer-events: none;
}

.cs-matrix__dot--flip { flex-direction: column-reverse; }

.cs-matrix__mark {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--muted);
  flex-shrink: 0;
}

.cs-matrix__dot--rulya .cs-matrix__mark {
  background: var(--accent);
  width: 9px;
  height: 9px;
}

.cs-matrix__dot-label {
  font-size: 0.6rem;
  color: var(--text);
  white-space: nowrap;
  line-height: 1;
  font-family: var(--font-body);
}

.cs-matrix__dot--rulya .cs-matrix__dot-label {
  color: var(--accent);
  font-weight: 600;
}

.cs-matrix__caption {
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
  text-align: center;
}

/* ── Results chart ──────────────────────────────────────── */
.cs-chart-wrap {
  margin-bottom: clamp(3rem, 5vw, 4rem);
}

.cs-chart__title {
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 1rem;
}

.cs-chart {
  display: block;
  width: 100%;
  border-radius: 6px;
  border: 1px solid var(--border);
}

.cs-chart__caption {
  font-size: 0.8rem;
  color: var(--muted);
  margin-top: 0.75rem;
  font-style: italic;
}

/* ── Article body ───────────────────────────────────────── */
.cs-article {
  padding-top: clamp(60px, 8vw, 100px);
  padding-bottom: clamp(20px, 3vw, 40px);
  border-top: 1px solid var(--border);
}

.cs-section {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 2rem 4rem;
  padding-block: clamp(4rem, 8vw, 6.5rem);
  border-top: 1px solid var(--border);
}

.cs-section:first-child { border-top: none; padding-top: 0; }

.cs-section__label {
  padding-top: 0.3rem;
}

.cs-section__label::before {
  content: '';
  display: block;
  width: 2rem;
  height: 2px;
  background: var(--accent);
  margin-bottom: 1.125rem;
}

.cs-section__body p {
  font-size: 1.125rem;
  color: var(--text);
  line-height: 1.85;
  max-width: 68ch;
}

.cs-section__body p + p {
  margin-top: 1.25em;
}

/* ── Results ────────────────────────────────────────────── */
.cs-results {
  background: var(--surface);
  border-top: 1px solid var(--border);
  padding-block: clamp(80px, 10vw, 130px);
}

.cs-results > .container > .label {
  display: block;
  margin-bottom: 3rem;
}

.cs-stats-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 2.5rem 4rem;
}

.cs-stat {
  width: 200px;
  flex-shrink: 0;
}

.cs-stat__num {
  display: block;
  font-family: var(--font-display);
  font-size: clamp(2.25rem, 4vw, 3.75rem);
  font-weight: 800;
  letter-spacing: -0.04em;
  line-height: 1;
  color: var(--text);
  margin-bottom: 0.625rem;
}

.cs-stat__label {
  font-size: 0.8rem;
  color: var(--muted);
  line-height: 1.55;
}

/* ── Audience segment cards ─────────────────────────────── */
.cs-segments {
  margin-top: 3rem;
}

.cs-segments__title {
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 1.25rem;
}

.cs-segments-grid {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 1rem;
}

.cs-segment-card {
  grid-column: span 2;
  background: var(--bg);
  border: 1px solid var(--accent);
  border-radius: 6px;
  padding: 1rem 1.125rem;
}

.cs-segment-card:nth-child(4) { grid-column: 2 / span 2; }
.cs-segment-card:nth-child(5) { grid-column: 4 / span 2; }

.cs-segment-card__name {
  display: block;
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 0.375rem;
  line-height: 1.3;
}

.cs-segment-card__detail {
  font-size: 0.75rem;
  color: var(--muted);
  line-height: 1.6;
}

.cs-segment-card__detail span {
  display: block;
}

/* ── Supporting results detail ──────────────────────────── */
.cs-results-detail {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  margin-top: 3.5rem;
  padding-top: 3rem;
  border-top: 1px solid var(--border);
  max-width: 72ch;
}

.cs-results-detail li {
  font-size: 1.125rem;
  color: var(--text);
  line-height: 1.85;
  padding-left: 1.25rem;
  position: relative;
}

.cs-results-detail li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.65em;
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--accent);
}

/* ── Qualitative result list ────────────────────────────── */
.cs-result-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 2rem;
  margin-top: 0.5rem;
}

.cs-result-item {
  padding-left: 1.5rem;
  border-left: 2px solid var(--accent);
}

.cs-result-item p {
  font-size: 1.0625rem;
  color: var(--text);
  line-height: 1.8;
  max-width: 65ch;
}

/* ── Takeaway ───────────────────────────────────────────── */
.cs-takeaway {
  padding-block: clamp(80px, 10vw, 130px);
  border-top: 1px solid var(--border);
}

.cs-takeaway .label { margin-bottom: 1.5rem; }

.cs-takeaway__text {
  font-size: clamp(1.125rem, 2vw, 1.375rem);
  color: var(--text);
  line-height: 1.8;
  max-width: 72ch;
}

/* ── Tools ──────────────────────────────────────────────── */
.cs-tools {
  background: var(--surface);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding-block: 1.75rem;
}

.cs-tools__inner {
  display: flex;
  align-items: center;
  gap: 2rem;
  flex-wrap: wrap;
}

.cs-tools__list {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
}

.cs-tools__list li {
  font-size: 0.8125rem;
  color: var(--muted);
  padding-inline: 1.25rem;
  border-left: 1px solid var(--border);
}
.cs-tools__list li:first-child {
  padding-left: 0;
  border-left: none;
}

/* ── Bottom nav (back button) ───────────────────────────── */
.cs-foot-nav {
  padding-block: clamp(60px, 8vw, 100px);
}

/* ── SONAS email mockup + flow diagrams ─────────────────── */
.cs-email-mockup {
  border-radius: 10px;
  overflow: hidden;
  border: 1px solid var(--border);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
}

.cs-email-mockup__chrome {
  background: #202020;
  border-bottom: 1px solid var(--border);
  padding: 0.5rem 0.75rem;
  display: flex;
  gap: 0.375rem;
  align-items: center;
}

.cs-email-mockup__dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
}
.cs-email-mockup__dot:nth-child(1) { background: #ff5f57; }
.cs-email-mockup__dot:nth-child(2) { background: #febc2e; }
.cs-email-mockup__dot:nth-child(3) { background: #28c840; }

.cs-email-mockup img {
  width: 100%;
  display: block;
}

.cs-email-caption {
  font-size: 0.7rem;
  color: var(--muted);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  text-align: left;
  margin-bottom: 0.875rem;
  line-height: 1.5;
}

.cs-flows {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.cs-flow {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1.125rem 1.25rem 1.375rem;
}

.cs-flow__title {
  font-size: 0.68rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 1rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--border);
}

.cs-flow__cadence {
  font-size: 0.7rem;
  color: var(--muted);
  font-style: italic;
  margin-bottom: 1rem;
}

.cs-flow__steps {
  display: flex;
  flex-direction: column;
}

.cs-flow__box {
  background: var(--bg);
  border: 1px solid rgba(237, 233, 223, 0.35);
  border-radius: 5px;
  padding: 0.55rem 0.875rem;
}

.cs-flow__box-name {
  display: block;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text);
  line-height: 1.3;
}

.cs-flow__box-detail {
  display: block;
  font-size: 0.68rem;
  color: var(--muted);
  margin-top: 0.2rem;
  line-height: 1.45;
}

.cs-flow__connector {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 0.25rem 0;
  gap: 0.1rem;
}

.cs-flow__interval {
  font-size: 0.58rem;
  color: var(--muted);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  line-height: 1;
}

.cs-flow__arrow {
  font-size: 0.875rem;
  color: var(--accent);
  line-height: 1;
  display: block;
}

/* ── Stat cards (The Numbers section) ──────────────────── */
.cs-stat-cards {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-top: 2.5rem;
}

.cs-stat-card {
  flex: 1;
  min-width: 120px;
}

.cs-stat-card__num {
  display: block;
  font-family: var(--font-display);
  font-size: clamp(1.75rem, 3vw, 2.75rem);
  font-weight: 800;
  letter-spacing: -0.04em;
  line-height: 1;
  color: var(--text);
  margin-bottom: 0.5rem;
}

.cs-stat-card__num sup {
  font-size: 0.5em;
  vertical-align: super;
  letter-spacing: 0;
}

.cs-stat-card__label {
  font-size: 0.75rem;
  color: var(--muted);
  line-height: 1.45;
}

/* ── Standalone matrix (full-width, fixed height) ──────── */
.cs-matrix-standalone {
  position: relative;
  height: 340px;
  margin-top: 2rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 6px;
  overflow: hidden;
}

.cs-matrix--lime .cs-matrix__vline,
.cs-matrix--lime .cs-matrix__hline {
  background: rgba(198, 255, 0, 0.5);
}

/* ── The Tension diagram ────────────────────────────────── */
.cs-tension {
  display: flex;
  align-items: flex-start;
  margin-top: 2.5rem;
}

.cs-tension__col {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.cs-tension__arrow {
  flex-shrink: 0;
  width: 2.5rem;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding-top: 1rem;
  font-size: 1rem;
  color: var(--accent);
}

.cs-tension__box {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 0.875rem 1rem;
}

.cs-tension__box-name {
  display: block;
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 0.375rem;
  line-height: 1.3;
}

.cs-tension__box-detail {
  display: block;
  font-size: 0.7rem;
  color: var(--muted);
  line-height: 1.5;
}

.cs-tension__down {
  text-align: center;
  font-size: 1rem;
  color: var(--accent);
  line-height: 1.5;
}

.cs-tension__trap {
  background: rgba(198, 255, 0, 0.06);
  border: 1px solid var(--accent);
  border-radius: 6px;
  padding: 0.875rem 1rem;
}

.cs-tension__trap-name {
  display: block;
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 0.375rem;
  line-height: 1.3;
}

.cs-tension__trap-detail {
  display: block;
  font-size: 0.7rem;
  color: var(--muted);
  line-height: 1.5;
}

/* ── Responsive ─────────────────────────────────────────── */
@media (max-width: 900px) {
  .cs-section {
    grid-template-columns: 1fr;
    gap: 1rem;
  }



  .cs-built-cols {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  .cs-hero__title {
    font-size: clamp(4rem, 18vw, 8rem);
    letter-spacing: 0.03em;
  }

  .cs-hero__title--long {
    font-size: 6.5vw;
  }

  .cs-tension {
    flex-direction: column;
    gap: 0.75rem;
  }

  .cs-tension__arrow {
    display: none;
  }

  .cs-email-collage {
    grid-template-columns: 1fr;
  }

  .cs-segments-grid {
    grid-template-columns: 1fr;
  }

  .cs-segment-card,
  .cs-segment-card:nth-child(4),
  .cs-segment-card:nth-child(5) {
    grid-column: 1;
  }

  .cs-callout__grid {
    grid-template-columns: 1fr;
    gap: 0;
  }

  .cs-callout__item {
    padding-inline: 0;
    border-left: none;
    border-top: 1px solid var(--border);
    padding-block: 2rem;
  }

  .cs-callout__item:first-child {
    border-top: none;
    padding-top: 0;
  }

  .cs-tools__inner {
    flex-direction: column;
    align-items: flex-start;
    gap: 1rem;
  }
}