.case-body {
  background: var(--paper-bright);
}

.case-header {
  position: absolute;
  color: var(--paper);
}

.case-header.scrolled {
  position: fixed;
  color: var(--ink);
}

.case-hero {
  min-height: 100svh;
  padding: 8.5rem var(--page-pad) 4rem;
  color: var(--paper);
  background: var(--case-color, var(--ink));
}

.case-hero-inner,
.case-content,
.case-next-inner,
.archive-hero-inner,
.archive-content {
  max-width: calc(var(--max-width) - 2 * var(--page-pad));
  margin: 0 auto;
}

.case-content,
.archive-content {
  width: calc(100% - 2 * var(--page-pad));
}

.case-back {
  display: inline-flex;
  gap: 0.75rem;
  align-items: center;
  min-height: 2.75rem;
  margin-bottom: clamp(3rem, 7vw, 7rem);
  font-family: var(--mono);
  font-size: var(--text-caption);
  font-weight: 800;
  letter-spacing: 0.07em;
  text-transform: uppercase;
}

.case-back span { transition: transform 180ms ease; }
.case-back:hover span { transform: translateX(-4px); }

.case-kicker {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin: 0 0 1.2rem;
  font-family: var(--mono);
  font-size: var(--text-caption);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.case-kicker::before {
  content: "";
  width: 2.5rem;
  height: 1px;
  background: currentColor;
}

.case-title {
  max-width: 76rem;
  margin: 0;
  font-size: clamp(4rem, 10vw, 10.5rem);
  font-weight: 850;
  letter-spacing: -0.08em;
  line-height: 0.82;
}

.case-title em {
  display: block;
  font-family: var(--display);
  font-weight: 400;
}

.case-intro-grid {
  display: grid;
  grid-template-columns: 1.45fr 0.55fr;
  gap: clamp(3rem, 9vw, 10rem);
  align-items: end;
  margin-top: clamp(4rem, 9vw, 8rem);
}

.case-intro {
  max-width: 48rem;
  margin: 0;
  font-family: var(--display);
  font-size: clamp(1.45rem, 2.6vw, 2.55rem);
  line-height: 1.25;
}

.case-facts {
  display: grid;
  margin: 0;
  border-top: 1px solid currentColor;
}

.case-facts > div {
  display: grid;
  grid-template-columns: 5rem 1fr;
  gap: 1rem;
  padding: 0.8rem 0;
  border-bottom: 1px solid currentColor;
}

.case-facts dt {
  font-family: var(--mono);
  font-size: var(--text-caption);
  font-weight: 800;
  text-transform: uppercase;
}

.case-facts dd {
  margin: 0;
  font-size: 0.875rem;
}

.case-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-top: 2rem;
}

.case-hero .button {
  color: var(--paper);
  border-color: var(--paper);
}

.case-hero .button:hover {
  color: var(--ink);
  border-color: var(--acid);
  background: var(--acid);
}

.case-content {
  padding: clamp(5rem, 10vw, 10rem) 0;
}

.case-section {
  display: grid;
  grid-template-columns: minmax(10rem, 0.35fr) minmax(0, 1fr);
  gap: clamp(2rem, 8vw, 8rem);
  padding: clamp(4rem, 8vw, 7rem) 0;
  border-top: 1px solid var(--ink);
}

.case-section:first-child { padding-top: 0; border-top: 0; }

.case-section-label {
  margin: 0;
  font-family: var(--mono);
  font-size: var(--text-caption);
  font-weight: 800;
  letter-spacing: 0.07em;
  text-transform: uppercase;
}

.case-section-main h2 {
  max-width: 55rem;
  margin: 0 0 2rem;
  font-size: clamp(2.7rem, 5.5vw, 5.8rem);
  letter-spacing: -0.065em;
  line-height: 0.95;
}

.case-section-main h2 em {
  font-family: var(--display);
  font-weight: 400;
}

.case-section-main > p {
  max-width: 47rem;
  margin: 0 0 1.25rem;
  color: rgba(29, 29, 31, 0.78);
  font-size: clamp(1rem, 1.35vw, 1.17rem);
}

.case-callout {
  display: grid;
  grid-template-columns: 0.35fr 1fr;
  gap: 2rem;
  margin: 3rem 0 0;
  padding: 1.5rem;
  color: var(--paper);
  background: var(--ink);
}

.case-callout span {
  font-family: var(--mono);
  font-size: var(--text-caption);
  text-transform: uppercase;
}

.case-callout p {
  margin: 0;
  font-family: var(--display);
  font-size: clamp(1.25rem, 2vw, 1.8rem);
  line-height: 1.3;
}

.architecture-panel {
  position: relative;
  margin-top: 2.5rem;
  padding: clamp(1rem, 3vw, 2rem);
  border: 1px solid var(--ink);
  background: #f2f2f4;
}

.architecture-panel img {
  display: block;
  width: 100%;
  height: auto;
  mix-blend-mode: multiply;
}

.architecture-caption,
.evidence-caption {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  margin-top: 1rem;
  font-family: var(--mono);
  font-size: var(--text-micro);
  text-transform: uppercase;
}

.decision-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  border-top: 1px solid var(--ink);
  border-left: 1px solid var(--ink);
}

.decision-card {
  min-height: 15rem;
  padding: 1.4rem;
  border-right: 1px solid var(--ink);
  border-bottom: 1px solid var(--ink);
}

.decision-card span {
  display: block;
  margin-bottom: 3.5rem;
  font-family: var(--mono);
  font-size: var(--text-caption);
}

.decision-card h3 {
  margin: 0 0 0.7rem;
  font-size: 1.35rem;
  letter-spacing: -0.04em;
}

.decision-card p {
  margin: 0;
  font-size: 0.9375rem;
}

.metric-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  margin-top: 2.5rem;
  border-top: 1px solid var(--ink);
  border-left: 1px solid var(--ink);
}

.metric {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  min-height: 13rem;
  padding: 1.2rem;
  border-right: 1px solid var(--ink);
  border-bottom: 1px solid var(--ink);
}

.metric strong {
  font-family: var(--display);
  font-size: clamp(2.3rem, 5vw, 5rem);
  font-weight: 400;
  letter-spacing: -0.06em;
  line-height: 1;
}

.metric span {
  max-width: 12rem;
  font-size: var(--text-caption);
  font-weight: 750;
  line-height: 1.35;
}

.tour {
  overflow: hidden;
  border: 1px solid var(--ink);
  background: var(--paper);
}

.tour-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.8rem 1rem;
  color: var(--paper);
  background: var(--ink);
  font-family: var(--mono);
  font-size: var(--text-caption);
  text-transform: uppercase;
}

.tour-play {
  min-height: 2.75rem;
  padding: 0.4rem 0.65rem;
  color: var(--ink);
  border: 0;
  background: var(--acid);
  font-family: var(--mono);
  font-size: var(--text-caption);
  font-weight: 800;
  cursor: pointer;
  text-transform: uppercase;
}

.tour-steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  margin: 0;
  padding: 0;
  list-style: none;
  border-bottom: 1px solid var(--ink);
}

.tour-steps button {
  width: 100%;
  min-height: 6rem;
  padding: 1rem;
  text-align: left;
  border: 0;
  border-right: 1px solid var(--ink);
  background: transparent;
  cursor: pointer;
}

.tour-steps li:last-child button { border-right: 0; }
.tour-steps button.active { background: var(--tour-accent, var(--acid)); }

.tour-steps small,
.tour-steps strong {
  display: block;
}

.tour-steps small {
  margin-bottom: 1rem;
  font-family: var(--mono);
  font-size: var(--text-micro);
}

.tour-steps strong {
  font-size: 0.75rem;
  text-transform: uppercase;
}

.tour-panels {
  min-height: 14rem;
  padding: clamp(1.5rem, 4vw, 3.5rem);
}

.tour-panel {
  max-width: 47rem;
}

.tour-panel[hidden] { display: none; }

.tour-panel p:first-child {
  margin: 0 0 0.7rem;
  color: var(--coral-ink);
  font-family: var(--mono);
  font-size: var(--text-caption);
  font-weight: 800;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.tour-panel h3 {
  margin: 0 0 1rem;
  font-family: var(--display);
  font-size: clamp(1.8rem, 3vw, 3rem);
  font-weight: 400;
  line-height: 1;
}

.tour-panel p:last-child { margin: 0; }

.evidence-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.25rem;
}

.evidence-item {
  margin: 0;
  padding: 0.8rem;
  border: 1px solid var(--ink);
  background: #f2f2f4;
}

.evidence-item:first-child:last-child { grid-column: 1 / -1; }

.evidence-item img {
  display: block;
  width: 100%;
  height: clamp(15rem, 30vw, 26rem);
  aspect-ratio: 16 / 10;
  object-fit: cover;
  object-position: top;
  border: 1px solid var(--line-dark);
}

.case-list {
  display: grid;
  gap: 0;
  margin: 2rem 0 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--ink);
}

.case-list li {
  display: grid;
  grid-template-columns: 2rem 1fr;
  gap: 1rem;
  padding: 1rem 0;
  border-bottom: 1px solid var(--ink);
}

.case-list li::before {
  content: "↳";
  color: var(--coral-ink);
  font-family: var(--mono);
}

.kafka-architecture {
  display: grid;
  grid-template-columns: 1fr auto 1fr auto 1fr auto 1fr;
  align-items: center;
  margin-top: 2.5rem;
  padding: clamp(1rem, 3vw, 2rem);
  border: 1px solid var(--ink);
  background: var(--acid);
}

.kafka-architecture div {
  display: flex;
  flex-direction: column;
  justify-content: center;
  min-height: 9rem;
  padding: 1rem;
  border: 1px solid var(--ink);
  background: var(--paper);
}

.kafka-architecture small,
.kafka-architecture span {
  font-family: var(--mono);
  font-size: var(--text-micro);
  text-transform: uppercase;
}

.kafka-architecture strong {
  margin: 1.2rem 0 0.3rem;
  font-size: 1rem;
  line-height: 1.1;
}

.kafka-architecture > i {
  padding: 0 0.45rem;
  font-family: var(--mono);
  font-style: normal;
}

.case-next {
  padding: clamp(5rem, 10vw, 9rem) var(--page-pad);
  color: var(--paper);
  background: var(--ink);
}

.case-next a {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 2rem;
}

.case-next span {
  font-family: var(--mono);
  font-size: var(--text-caption);
  text-transform: uppercase;
}

.case-next strong {
  display: block;
  margin-top: 1rem;
  font-size: clamp(3rem, 8vw, 8rem);
  letter-spacing: -0.07em;
  line-height: 0.9;
}

.case-next i {
  color: var(--acid);
  font-family: var(--display);
  font-size: clamp(3rem, 8vw, 8rem);
  font-style: normal;
  transition: transform 200ms ease;
}

.case-next a:hover i { transform: translateX(0.5rem); }

.case-tradestream { --case-color: #1d1d1f; --tour-accent: #8fd3ff; }
.case-commitscope { --case-color: #005a87; --tour-accent: #8fd3ff; }
.case-kafka { --case-color: #3a3a3c; --tour-accent: #8fd3ff; }

/* Project archive */
.archive-hero {
  padding: 10rem var(--page-pad) clamp(5rem, 9vw, 9rem);
  color: var(--paper);
  background: var(--ink);
}

.archive-hero h1 {
  max-width: 75rem;
  margin: 0;
  font-size: clamp(4.5rem, 11vw, 11rem);
  letter-spacing: -0.08em;
  line-height: 0.82;
}

.archive-hero h1 em {
  display: block;
  color: var(--acid);
  font-family: var(--display);
  font-weight: 400;
}

.archive-hero p:last-child {
  max-width: 38rem;
  margin: 3rem 0 0 auto;
  color: rgba(245,245,247,.72);
  font-size: 1.05rem;
}

.archive-content {
  padding: clamp(5rem, 10vw, 10rem) 0;
}

.archive-filter {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
  margin-bottom: 2.5rem;
}

.archive-filter button {
  min-height: 2.75rem;
  padding: 0.5rem 0.8rem;
  border: 1px solid var(--ink);
  border-radius: 2rem;
  background: transparent;
  font-family: var(--mono);
  font-size: var(--text-caption);
  font-weight: 800;
  cursor: pointer;
  text-transform: uppercase;
}

.archive-filter button.active,
.archive-filter button:hover {
  color: var(--paper);
  background: var(--ink);
}

.archive-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border-top: 1px solid var(--ink);
  border-left: 1px solid var(--ink);
}

.archive-card {
  display: flex;
  flex-direction: column;
  min-height: 27rem;
  padding: 1.3rem;
  border-right: 1px solid var(--ink);
  border-bottom: 1px solid var(--ink);
  transition: color 200ms ease, background 200ms ease;
}

.archive-card[hidden] { display: none; }
.archive-card:hover { color: var(--paper); background: var(--ink); }

.archive-card-num {
  display: flex;
  justify-content: space-between;
  font-family: var(--mono);
  font-size: var(--text-caption);
  text-transform: uppercase;
}

.archive-card h2 {
  margin: auto 0 1rem;
  font-size: clamp(2rem, 3.2vw, 3.6rem);
  letter-spacing: -0.06em;
  line-height: 0.94;
}

.archive-card p {
  margin: 0 0 1.5rem;
  font-size: 0.9375rem;
}

.archive-card-links {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  padding-top: 0.8rem;
  border-top: 1px solid currentColor;
  font-family: var(--mono);
  font-size: var(--text-caption);
  font-weight: 800;
  text-transform: uppercase;
}

.archive-card-links a:hover { color: var(--coral); }

.archive-card-links a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 2.75rem;
  min-height: 2.75rem;
}

.archive-status {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}

.archive-status::before {
  content: "";
  width: 0.38rem;
  height: 0.38rem;
  border-radius: 50%;
  background: var(--acid);
}

@media (max-width: 900px) {
  .case-intro-grid,
  .case-section { grid-template-columns: 1fr; }
  .case-section { gap: 2rem; }
  .archive-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 640px) {
  .case-hero { padding-top: 7rem; }
  .case-title { font-size: clamp(3.6rem, 18vw, 6.3rem); }
  .case-intro-grid { margin-top: 3.5rem; }
  .case-hero-actions { align-items: flex-start; flex-direction: column; }
  .decision-grid,
  .metric-grid,
  .evidence-grid,
  .archive-grid { grid-template-columns: 1fr; }
  .evidence-item:first-child:last-child { grid-column: auto; }
  .tour-steps { grid-template-columns: repeat(2, 1fr); }
  .tour-steps li:nth-child(2) button { border-right: 0; }
  .tour-steps li:nth-child(-n+2) { border-bottom: 1px solid var(--ink); }
  .case-callout { grid-template-columns: 1fr; gap: 1rem; }
  .archive-card { min-height: 21rem; }
  .kafka-architecture { grid-template-columns: 1fr; gap: 0.6rem; }
  .kafka-architecture > i { text-align: center; transform: rotate(90deg); }
}

/* Readability-first case-study and archive layouts. */
.case-hero {
  min-height: auto;
  padding-top: 8rem;
  padding-bottom: 6rem;
}

.case-hero-inner,
.case-content,
.case-next-inner,
.archive-hero-inner,
.archive-content {
  max-width: var(--max-width);
}

.case-back {
  margin-bottom: clamp(2.5rem, 5vw, 4.5rem);
}

.case-title {
  max-width: 62rem;
  font-size: clamp(3.75rem, 8vw, 7.5rem);
  letter-spacing: -0.065em;
  line-height: 0.9;
}

.case-intro-grid {
  grid-template-columns: minmax(0, 1.25fr) minmax(16rem, 0.75fr);
  gap: clamp(3rem, 7vw, 7rem);
  margin-top: clamp(3rem, 6vw, 5rem);
}

.case-intro {
  max-width: 43rem;
  font-size: clamp(1.35rem, 2.2vw, 2rem);
  line-height: 1.35;
}

.case-content {
  max-width: 62rem;
  padding-top: clamp(4.5rem, 8vw, 7rem);
  padding-bottom: clamp(4.5rem, 8vw, 7rem);
}

.case-section {
  grid-template-columns: 1fr;
  gap: 1.25rem;
  padding: clamp(3.5rem, 6vw, 5rem) 0;
  border-color: var(--line-dark);
}

.case-section-main h2 {
  max-width: 48rem;
  margin-bottom: 1.5rem;
  font-size: clamp(2.5rem, 4.5vw, 4.5rem);
  line-height: 1;
}

.case-section-main > p {
  max-width: 44rem;
  font-size: 1.0625rem;
  line-height: 1.7;
}

.case-callout,
.architecture-panel,
.tour,
.evidence-item,
.decision-card,
.metric {
  border-color: var(--line-dark);
}

.case-callout,
.architecture-panel,
.tour {
  border-radius: 1.25rem;
  overflow: hidden;
}

.case-callout {
  grid-template-columns: minmax(8rem, 0.3fr) 1fr;
  margin-top: 2.5rem;
  padding: 1.75rem;
}

.architecture-panel {
  padding: clamp(1rem, 2.5vw, 1.75rem);
}

.decision-grid,
.metric-grid {
  gap: 1rem;
  border: 0;
}

.decision-card,
.metric {
  border: 1px solid var(--line-dark);
  border-radius: 1rem;
  background: var(--paper-bright);
}

.decision-card {
  min-height: 13rem;
}

.decision-card span {
  margin-bottom: 2.5rem;
}

.metric {
  min-height: 11rem;
}

.tour-steps {
  border-color: var(--line-dark);
}

.tour-steps button {
  border-color: var(--line-dark);
}

.evidence-grid {
  gap: 1rem;
}

.evidence-item {
  border-radius: 1rem;
}

.kafka-architecture {
  border-color: var(--line-dark);
  border-radius: 1.25rem;
  background: var(--aqua);
}

.kafka-architecture div {
  border-color: var(--line-dark);
  border-radius: 0.75rem;
  background: var(--paper-bright);
}

.case-next {
  padding-top: clamp(4.5rem, 8vw, 7rem);
  padding-bottom: clamp(4.5rem, 8vw, 7rem);
}

.case-next strong,
.case-next i {
  font-size: clamp(3rem, 6vw, 6rem);
}

.archive-hero {
  padding-top: 9rem;
  padding-bottom: 6rem;
}

.archive-hero h1 {
  max-width: 64rem;
  font-size: clamp(4rem, 8vw, 7.75rem);
  line-height: 0.9;
}

.archive-hero p:last-child {
  max-width: 42rem;
  margin: 2rem 0 0;
  font-size: 1.0625rem;
  line-height: 1.65;
}

.archive-content {
  padding-top: clamp(4.5rem, 8vw, 7rem);
  padding-bottom: clamp(4.5rem, 8vw, 7rem);
}

.archive-filter {
  margin-bottom: 2rem;
}

.archive-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
  border: 0;
}

.archive-card {
  min-height: 22rem;
  padding: 1.75rem;
  border: 1px solid var(--line-dark);
  border-radius: 1.25rem;
  background: var(--paper-bright);
}

.archive-card:hover {
  color: var(--ink);
  border-color: rgba(0, 113, 227, 0.45);
  background: var(--paper-bright);
}

.archive-card h2 {
  margin: 3rem 0 1rem;
  font-size: clamp(2.25rem, 3vw, 3.25rem);
  line-height: 1;
}

.archive-card p {
  max-width: 34rem;
  line-height: 1.65;
}

.archive-card-links {
  margin-top: auto;
  border-color: var(--line-dark);
}

.archive-card-links a:hover {
  color: var(--coral-ink);
}

@media (max-width: 900px) {
  .case-intro-grid {
    grid-template-columns: 1fr;
  }

  .case-facts {
    max-width: 34rem;
  }
}

@media (max-width: 640px) {
  .case-hero {
    padding-top: 7rem;
    padding-bottom: 4.5rem;
  }

  .case-title {
    font-size: clamp(3.1rem, 15vw, 4.75rem);
    line-height: 0.94;
  }

  .case-intro-grid {
    gap: 2rem;
    margin-top: 2.5rem;
  }

  .case-intro {
    font-size: 1.25rem;
  }

  .case-content,
  .archive-content {
    width: calc(100% - 2 * var(--page-pad));
  }

  .case-section {
    padding: 3.25rem 0;
  }

  .case-section-main h2 {
    font-size: clamp(2.4rem, 12vw, 3.5rem);
  }

  .case-callout {
    grid-template-columns: 1fr;
    gap: 0.75rem;
    padding: 1.25rem;
  }

  .decision-grid,
  .metric-grid,
  .evidence-grid,
  .archive-grid {
    grid-template-columns: 1fr;
  }

  .tour-steps {
    grid-template-columns: 1fr 1fr;
  }

  .tour-steps button {
    min-height: 5.25rem;
  }

  .archive-hero {
    padding-top: 8rem;
    padding-bottom: 4.5rem;
  }

  .archive-hero h1 {
    font-size: clamp(3.4rem, 16vw, 5rem);
  }

  .archive-card {
    min-height: 19rem;
  }
}