.implementation-page {
  --implementation-panel: rgba(18, 23, 28, 0.78);
  --implementation-panel-strong: rgba(18, 23, 28, 0.94);
  --implementation-accent: #86d3df;
}

.implementation-page::before {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background:
    linear-gradient(90deg, rgba(8, 31, 39, 0.84), transparent 34%, transparent 68%, rgba(8, 22, 29, 0.82)),
    radial-gradient(circle at 72% 12%, rgba(134, 211, 223, 0.08), transparent 34%);
  content: "";
}

.implementation-page .site-header {
  width: min(100% - 36px, var(--max-width));
  padding: 14px 0;
}

.implementation-page .brand {
  min-height: 44px;
  padding: 4px 12px 4px 4px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(18, 23, 28, 0.76);
}

.implementation-nav {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 5px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(18, 23, 28, 0.76);
}

.implementation-nav a {
  padding: 8px 12px;
  border-radius: 6px;
  color: var(--muted);
  font-size: 14px;
}

.implementation-nav a:hover,
.implementation-nav a:focus-visible {
  background: var(--soft);
  color: var(--implementation-accent);
  outline: none;
}

.implementation-main {
  width: min(100% - 36px, var(--max-width));
  margin: 0 auto;
}

.implementation-hero {
  display: grid;
  align-content: center;
  min-height: 70vh;
  min-height: 70dvh;
  padding: 96px 0 112px;
  border-bottom: 1px solid var(--line);
}

.implementation-hero h1 {
  max-width: 980px;
  font-size: clamp(42px, 7vw, 82px);
  line-height: 1.02;
}

.implementation-intro {
  max-width: 760px;
  margin: 28px 0 0;
  color: var(--muted);
  font-size: clamp(17px, 2vw, 21px);
  line-height: 1.8;
}

.implementation-link {
  display: inline-flex;
  align-items: center;
  width: fit-content;
  gap: 10px;
  margin-top: 34px;
  padding: 11px 15px;
  border: 1px solid rgba(134, 211, 223, 0.34);
  border-radius: var(--radius);
  color: var(--implementation-accent);
  font-size: 14px;
  font-weight: 700;
}

.implementation-link:hover,
.implementation-link:focus-visible {
  background: rgba(134, 211, 223, 0.1);
  outline: none;
}

.implementation-section {
  padding: 96px 0;
  border-bottom: 1px solid var(--line);
}

#cases,
#case-1,
#case-2,
#case-3,
#boundary {
  scroll-margin-top: 96px;
}

.implementation-heading {
  display: grid;
  grid-template-columns: minmax(0, 0.8fr) minmax(320px, 1.2fr);
  gap: 32px 64px;
  align-items: end;
  margin-bottom: 40px;
}

.implementation-heading .section-kicker {
  grid-column: 1 / -1;
  margin-bottom: -20px;
}

.implementation-heading h2 {
  max-width: 560px;
}

.implementation-heading > p:last-child {
  max-width: 620px;
  margin: 0;
  color: var(--muted);
  font-size: 17px;
}

.problem-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  border-top: 1px solid var(--line);
  border-left: 1px solid var(--line);
}

.problem-card {
  min-height: 250px;
  padding: 26px;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: var(--implementation-panel);
}

.problem-index,
.case-number {
  color: var(--implementation-accent);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.problem-card h3 {
  margin-top: 42px;
  font-size: 24px;
}

.problem-card p {
  margin: 14px 0 0;
  color: var(--muted);
  font-size: 15px;
}

.case-entry-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.case-entry {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 12px 18px;
  align-content: start;
  min-height: 260px;
  padding: 26px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--implementation-panel);
  transition:
    border-color 180ms ease,
    background 180ms ease,
    transform 180ms ease;
}

.case-entry:hover,
.case-entry:focus-visible {
  border-color: rgba(134, 211, 223, 0.5);
  background: rgba(21, 38, 45, 0.94);
  outline: none;
  transform: translateY(-2px);
}

.case-entry.is-featured {
  grid-column: 1 / -1;
  min-height: 230px;
  border-left: 4px solid var(--implementation-accent);
  background:
    linear-gradient(120deg, rgba(95, 184, 201, 0.12), transparent 62%),
    var(--implementation-panel-strong);
}

.case-entry.is-concept {
  border-style: dashed;
  background: rgba(18, 23, 28, 0.54);
}

.case-entry h3 {
  grid-column: 1 / -1;
  max-width: 860px;
  margin-top: 18px;
  font-size: clamp(24px, 3vw, 36px);
  line-height: 1.16;
}

.case-entry p {
  grid-column: 1 / -1;
  max-width: 720px;
  margin: 0;
  color: var(--muted);
}

.case-entry strong {
  grid-column: 1 / -1;
  align-self: end;
  margin-top: 18px;
  color: var(--implementation-accent);
  font-size: 14px;
}

.case-detail-section {
  display: grid;
  gap: 24px;
  padding: 96px 0;
  border-bottom: 1px solid var(--line);
}

.case-detail {
  padding: clamp(24px, 4vw, 44px);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--implementation-panel);
  box-shadow: 0 18px 48px rgba(0, 0, 0, 0.14);
}

.case-detail.is-primary {
  border-left: 4px solid var(--implementation-accent);
}

.case-detail.is-concept {
  border-style: dashed;
  background: rgba(18, 23, 28, 0.58);
}

.case-detail-summary {
  display: block;
  cursor: pointer;
  list-style: none;
}

.case-detail-summary::-webkit-details-marker {
  display: none;
}

.case-detail-summary:focus-visible {
  outline: 2px solid rgba(134, 211, 223, 0.54);
  outline-offset: 8px;
}

.summary-action {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: 20px;
  color: var(--implementation-accent);
  font-size: 13px;
  font-weight: 700;
}

.summary-action span {
  display: inline-grid;
  width: 22px;
  height: 22px;
  place-items: center;
  border: 1px solid rgba(134, 211, 223, 0.28);
  border-radius: 50%;
  transition: transform 180ms ease;
}

.case-detail[open] .summary-action span {
  transform: rotate(45deg);
}

.case-detail:not([open]) {
  box-shadow: none;
}

.case-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.case-state {
  padding: 5px 9px;
  border: 1px solid rgba(134, 211, 223, 0.28);
  border-radius: 999px;
  color: var(--muted);
  font-size: 12px;
  white-space: nowrap;
}

.case-state.is-evidence {
  color: #bceab6;
}

.case-state.is-validating {
  color: #f2d58b;
}

.case-state.is-concept {
  color: #b8c9ee;
}

.case-detail h3 {
  max-width: 920px;
  margin-top: 22px;
  font-size: clamp(27px, 4vw, 42px);
  line-height: 1.15;
}

.case-summary {
  max-width: 820px;
  margin: 18px 0 0;
  color: var(--muted);
  font-size: 17px;
}

.case-detail-body {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(360px, 1.1fr);
  gap: 24px;
  margin-top: 32px;
}

.case-details {
  display: grid;
  align-content: start;
  margin: 0;
  border-top: 1px solid var(--line);
  border-left: 1px solid var(--line);
}

.case-fact {
  min-height: 126px;
  padding: 20px;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.case-details dt {
  color: var(--implementation-accent);
  font-size: 13px;
  font-weight: 800;
}

.case-details dd {
  margin: 10px 0 0;
  color: rgba(232, 238, 240, 0.82);
  font-size: 15px;
}

.case-evidence {
  padding: 22px;
  border: 1px solid rgba(134, 211, 223, 0.22);
  border-radius: var(--radius);
  background: rgba(8, 24, 31, 0.52);
}

.case-evidence h4 {
  margin: 0;
  color: var(--implementation-accent);
  font-size: 14px;
}

.evidence-list {
  display: grid;
  gap: 0;
  margin: 16px 0 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line);
}

.evidence-list li {
  display: grid;
  grid-template-columns: 86px minmax(0, 1fr);
  gap: 14px;
  padding: 15px 0;
  border-bottom: 1px solid var(--line);
}

.evidence-list strong {
  color: var(--ink);
  font-size: 14px;
}

.evidence-list span {
  color: var(--muted);
  font-size: 14px;
}

.evidence-links {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.evidence-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: 18px;
  padding: 9px 11px;
  border: 1px solid rgba(134, 211, 223, 0.26);
  border-radius: 6px;
  color: var(--implementation-accent);
  font-size: 13px;
  font-weight: 700;
}

.evidence-link:hover,
.evidence-link:focus-visible {
  background: rgba(134, 211, 223, 0.1);
  outline: none;
}

.implementation-boundary {
  margin: 96px 0;
  padding: clamp(28px, 5vw, 54px);
  border: 1px solid rgba(134, 211, 223, 0.28);
  border-radius: var(--radius);
  background:
    linear-gradient(135deg, rgba(95, 184, 201, 0.1), transparent 58%),
    var(--implementation-panel-strong);
}

.implementation-boundary h2 {
  font-size: clamp(30px, 4vw, 46px);
}

.implementation-boundary > p:last-child {
  max-width: 820px;
  margin: 20px 0 0;
  color: var(--muted);
  font-size: 18px;
  line-height: 1.8;
}

.implementation-cta {
  display: grid;
  justify-items: start;
  padding: 12px 0 104px;
}

.implementation-cta h2 {
  max-width: 760px;
}

.implementation-cta > p:not(.section-kicker) {
  max-width: 720px;
  margin: 20px 0 0;
  color: var(--muted);
  font-size: 17px;
}

.implementation-page .site-footer {
  width: min(100% - 36px, var(--max-width));
}

.implementation-page .site-footer a {
  color: var(--implementation-accent);
}

@media (max-width: 900px) {
  .problem-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .implementation-heading {
    grid-template-columns: 1fr;
  }

  .implementation-heading .section-kicker {
    margin-bottom: -16px;
  }

  .case-detail-body {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  .implementation-page .site-header {
    align-items: flex-start;
  }

  .implementation-nav {
    flex-wrap: wrap;
    justify-content: flex-end;
    max-width: 220px;
    background: transparent;
    border-color: transparent;
    padding: 0;
  }

  .implementation-nav a {
    padding: 7px 9px;
    border: 1px solid var(--line);
    background: rgba(18, 23, 28, 0.76);
    font-size: 12px;
  }

  .implementation-hero {
    min-height: auto;
    padding: 72px 0 84px;
  }

  .implementation-section {
    padding: 52px 0;
  }

  .problem-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .case-entry-grid {
    grid-template-columns: 1fr;
  }

  .problem-card {
    min-height: 168px;
    padding: 16px;
  }

  .problem-card h3 {
    margin-top: 22px;
    font-size: 20px;
  }

  .problem-card p {
    font-size: 13px;
    line-height: 1.55;
  }

  .case-entry,
  .case-entry.is-featured {
    grid-column: auto;
    min-height: 0;
    padding: 17px;
  }

  .case-entry h3 {
    margin-top: 6px;
    font-size: 22px;
  }

  .case-entry p {
    font-size: 14px;
    line-height: 1.55;
  }

  .case-entry strong {
    margin-top: 4px;
  }

  .case-detail-section {
    gap: 18px;
    padding: 52px 0;
  }

  .case-detail {
    padding: 18px 16px;
  }

  .case-detail h3 {
    font-size: 24px;
  }

  .case-detail-summary .case-summary {
    display: none;
  }

  .summary-action {
    margin-top: 14px;
  }

  .case-detail-body {
    gap: 16px;
    margin-top: 20px;
  }

  .case-head {
    align-items: flex-start;
    flex-direction: column;
  }

  .case-state {
    white-space: normal;
  }

  .case-fact {
    min-height: auto;
    padding: 14px;
  }

  .case-details dd {
    font-size: 14px;
  }

  .case-evidence {
    padding: 16px 14px;
  }

  .evidence-list li {
    grid-template-columns: 72px minmax(0, 1fr);
    gap: 10px;
    padding: 11px 0;
  }

  .evidence-list strong,
  .evidence-list span {
    font-size: 13px;
  }

  .implementation-boundary {
    margin: 52px 0;
  }

  .implementation-cta {
    padding-bottom: 68px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .implementation-page {
    scroll-behavior: auto;
  }
}