:root {
  --bg: #f7f8fa;
  --paper: #ffffff;
  --ink: #17202a;
  --muted: #5a6675;
  --line: #d8dee7;
  --accent: #0d5c63;
  --accent-soft: #dff1f0;
  --warning-bg: #fff4df;
  --warning-line: #d39b31;
  --shadow: 0 16px 40px rgba(28, 36, 48, 0.08);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: Arial, Helvetica, sans-serif;
  font-size: 16px;
  line-height: 1.6;
}

a {
  color: inherit;
}

.wrap {
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
}

.site-header {
  background: #16373d;
  color: #ffffff;
  padding: 56px 0 34px;
}

.eyebrow,
.section-label,
.card-kicker {
  margin: 0 0 10px;
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0;
  text-transform: uppercase;
}

.site-header .eyebrow {
  color: #b9ece9;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  max-width: 780px;
  margin-bottom: 14px;
  font-size: clamp(2.25rem, 5vw, 4rem);
  line-height: 1.05;
}

h2 {
  margin-bottom: 16px;
  font-size: clamp(1.65rem, 3vw, 2.35rem);
  line-height: 1.15;
}

h3 {
  margin-bottom: 10px;
  font-size: 1.1rem;
  line-height: 1.25;
}

.lead {
  max-width: 700px;
  color: #d6e6e8;
  font-size: 1.15rem;
}

.prototype-note {
  max-width: 720px;
  margin-bottom: 14px;
  color: #f6fbfb;
  font-weight: 700;
}

.back-link-wrap {
  margin-bottom: 0;
}

.back-link {
  color: #b9ece9;
  font-weight: 700;
}

.back-link:focus,
.back-link:hover {
  color: #ffffff;
}

.anchor-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 24px;
}

.anchor-nav a {
  display: inline-flex;
  min-height: 40px;
  align-items: center;
  border: 1px solid rgba(255, 255, 255, 0.35);
  border-radius: 8px;
  padding: 8px 12px;
  color: #ffffff;
  font-weight: 700;
  text-decoration: none;
}

.anchor-nav a:focus,
.anchor-nav a:hover {
  background: rgba(255, 255, 255, 0.14);
}

.boundary-banner {
  border-top: 4px solid var(--warning-line);
  border-bottom: 1px solid var(--warning-line);
  background: var(--warning-bg);
  padding: 24px 0;
}

.boundary-banner h2 {
  margin-bottom: 12px;
  font-size: 1.35rem;
}

.boundary-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px 22px;
  margin: 0;
  padding-left: 22px;
  font-weight: 700;
}

.section {
  padding: 56px 0;
}

.section-muted {
  background: #eef4f5;
}

.two-column {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(280px, 0.8fr);
  gap: 28px;
  align-items: start;
}

.plain-panel,
.story-card,
.case-shell {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--paper);
  box-shadow: var(--shadow);
}

.plain-panel {
  padding: 22px;
}

.plain-panel p,
.story-card p,
.case-shell p,
.detail-list dd {
  color: var(--muted);
}

.card-grid,
.panel-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
  margin-top: 26px;
}

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

.story-card {
  padding: 22px;
}

.story-card .card-kicker {
  color: #815a18;
}

.case-shell {
  overflow: hidden;
}

.pattern-strip {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  border-bottom: 1px solid var(--line);
  background: var(--accent-soft);
}

.pattern-strip span {
  padding: 14px 18px;
  color: #103f45;
  font-weight: 700;
}

.pattern-strip span + span {
  border-left: 1px solid var(--line);
}

.detail-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0;
  margin: 0;
}

.detail-list div {
  border-bottom: 1px solid var(--line);
  padding: 20px;
}

.detail-list div:nth-last-child(-n + 2) {
  border-bottom: 0;
}

.detail-list dt {
  margin-bottom: 6px;
  font-weight: 700;
}

.detail-list dd {
  margin: 0;
}

.ai-note {
  background: #ffffff;
}

.ai-note .wrap {
  border-left: 6px solid var(--accent);
  padding-left: 22px;
}

.site-footer {
  background: #17202a;
  color: #ffffff;
  padding: 26px 0;
}

.site-footer p {
  margin: 0;
  color: #e4eaef;
  font-weight: 700;
}

@media (max-width: 860px) {
  .two-column,
  .card-grid,
  .panel-grid,
  .detail-list,
  .pattern-strip,
  .boundary-list {
    grid-template-columns: 1fr;
  }

  .pattern-strip span + span {
    border-top: 1px solid var(--line);
    border-left: 0;
  }

  .detail-list div:nth-last-child(-n + 2) {
    border-bottom: 1px solid var(--line);
  }

  .detail-list div:last-child {
    border-bottom: 0;
  }
}

@media (max-width: 560px) {
  .site-header {
    padding: 38px 0 28px;
  }

  .section {
    padding: 38px 0;
  }

  .anchor-nav a {
    width: 100%;
    justify-content: center;
  }
}