:root {
  --surface: #ffffff;
  --muted-surface: #f7f7f8;
  --ink: #111111;
  --muted: #5d6268;
  --line: #d9dde2;
  --accent: #e4002b;
  --max: 1180px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--surface);
  color: var(--ink);
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
  line-height: 1.5;
}

a {
  color: inherit;
  text-decoration: none;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: 24px;
  padding: 18px clamp(20px, 5vw, 56px);
  border-bottom: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(12px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  letter-spacing: 0;
}

.brand-mark {
  width: 18px;
  height: 18px;
  background: var(--accent);
  display: inline-block;
}

.nav {
  display: flex;
  align-items: center;
  gap: 22px;
  font-size: 14px;
}

.nav a {
  border-bottom: 1px solid transparent;
}

.nav a:hover {
  border-bottom-color: var(--accent);
}

.hero {
  width: min(var(--max), calc(100vw - 40px));
  min-height: calc(100vh - 72px);
  margin: 0 auto;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(320px, 0.72fr);
  gap: clamp(32px, 6vw, 72px);
  align-items: center;
  border-left: 1px solid var(--line);
  border-right: 1px solid var(--line);
}

.hero-copy {
  padding: 56px 0 56px clamp(0px, 3vw, 34px);
}

.folio,
.section-number {
  margin: 0 0 24px;
  color: var(--accent);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0;
}

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

h1 {
  max-width: 760px;
  margin-bottom: 28px;
  font-size: clamp(44px, 7vw, 92px);
  line-height: 0.95;
  letter-spacing: 0;
  font-weight: 800;
}

h2 {
  margin-bottom: 24px;
  font-size: clamp(34px, 4.8vw, 64px);
  line-height: 1;
  letter-spacing: 0;
}

h3 {
  margin-bottom: 12px;
  font-size: 22px;
  line-height: 1.15;
}

.lead {
  max-width: 640px;
  color: var(--muted);
  font-size: clamp(18px, 2vw, 22px);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 34px;
}

.button {
  display: inline-flex;
  align-items: center;
  min-height: 46px;
  padding: 12px 18px;
  border: 1px solid var(--ink);
  font-weight: 700;
}

.button.primary {
  background: var(--ink);
  color: var(--surface);
}

.button.secondary {
  background: var(--surface);
}

.hero-visual {
  align-self: stretch;
  margin: 0;
  display: grid;
  grid-template-rows: 1fr auto;
  border-left: 1px solid var(--line);
  background: var(--muted-surface);
}

.hero-visual img {
  width: 100%;
  height: 100%;
  min-height: 360px;
  object-fit: cover;
  display: block;
}

.hero-visual figcaption {
  padding: 16px 18px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 14px;
}

.section {
  width: min(var(--max), calc(100vw - 40px));
  margin: 0 auto;
  padding: clamp(56px, 8vw, 96px) clamp(0px, 3vw, 34px);
  border-top: 1px solid var(--line);
  border-left: 1px solid var(--line);
  border-right: 1px solid var(--line);
}

.grid-section,
.archive-section {
  display: grid;
  grid-template-columns: 160px minmax(0, 1fr);
  gap: clamp(20px, 5vw, 64px);
}

.rule-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  border-top: 1px solid var(--line);
  border-left: 1px solid var(--line);
}

.rule-list article {
  min-height: 230px;
  padding: 24px;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.rule-list p,
.body-copy,
.steps p,
.archive-grid span,
.site-footer p {
  color: var(--muted);
}

.split-section {
  display: grid;
  grid-template-columns: 0.78fr 1fr;
  gap: clamp(28px, 6vw, 76px);
  background: var(--muted-surface);
}

.body-copy {
  max-width: 620px;
  font-size: 18px;
}

.steps {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.steps li {
  display: grid;
  grid-template-columns: 54px 120px 1fr;
  gap: 18px;
  padding: 20px 0;
  border-bottom: 1px solid var(--line);
}

.steps span {
  color: var(--accent);
  font-weight: 800;
  font-variant-numeric: tabular-nums;
}

.steps strong {
  font-size: 20px;
}

.steps p {
  margin-bottom: 0;
}

.archive-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  margin-top: 34px;
  border-top: 1px solid var(--line);
  border-left: 1px solid var(--line);
}

.archive-grid div {
  display: grid;
  gap: 10px;
  padding: 22px;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.site-footer {
  width: min(var(--max), calc(100vw - 40px));
  margin: 0 auto 40px;
  padding: 34px clamp(0px, 3vw, 34px);
  border: 1px solid var(--line);
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 24px;
  align-items: end;
}

.site-footer h2 {
  margin-bottom: 10px;
  font-size: clamp(28px, 4vw, 48px);
}

.site-footer p {
  margin-bottom: 0;
}

.mail {
  color: var(--accent);
  font-weight: 800;
}

@media (max-width: 860px) {
  .site-header,
  .hero,
  .grid-section,
  .split-section,
  .archive-section,
  .site-footer {
    grid-template-columns: 1fr;
  }

  .site-header {
    position: static;
  }

  .nav {
    flex-wrap: wrap;
    gap: 14px;
  }

  .hero {
    min-height: auto;
  }

  .hero-copy {
    padding: 42px 18px 20px;
  }

  .hero-visual {
    border-left: 0;
    border-top: 1px solid var(--line);
  }

  .section {
    padding-left: 18px;
    padding-right: 18px;
  }

  .rule-list,
  .archive-grid {
    grid-template-columns: 1fr;
  }

  .steps li {
    grid-template-columns: 44px 1fr;
  }

  .steps p {
    grid-column: 2;
  }
}

@media (max-width: 520px) {
  .hero,
  .section,
  .site-footer {
    width: calc(100vw - 24px);
  }

  h1 {
    font-size: 42px;
  }

  .button {
    width: 100%;
    justify-content: center;
  }
}