:root {
  --paper: #f2f0ea;
  --paper-alt: #e5e2d9;
  --ink: #1a1c22;
  --muted: #6e6b64;
  --accent: #a82c26;
  --blue: #2a4a6b;
  --sans: system-ui, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --serif: Georgia, "Times New Roman", serif;
  --rule: rgba(26, 28, 34, 0.18);
  --rule-light: rgba(242, 240, 234, 0.28);
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--serif);
  font-size: 18px;
  line-height: 1.7;
  overflow-x: hidden;
}

a { color: var(--accent); }

a:focus-visible,
img:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

.band--dark a:focus-visible { outline-color: var(--paper); }

.wrap {
  max-width: 1220px;
  margin: 0 auto;
  padding: 0 28px;
}

.grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  column-gap: 24px;
}

/* ---------- header ---------- */

.site-head {
  border-bottom: 1px solid var(--rule);
}

.head-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 14px 28px;
  padding: 20px 0 18px;
}

.brand {
  font-family: var(--sans);
  font-weight: 800;
  font-size: 21px;
  letter-spacing: -0.03em;
  color: var(--ink);
  text-decoration: none;
}

.site-head nav ul {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 22px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-family: var(--sans);
  font-size: 15px;
  line-height: 1.3;
}

.site-head nav a {
  color: var(--ink);
  text-decoration: none;
  padding-bottom: 3px;
  border-bottom: 1px solid transparent;
}

.site-head nav a:hover,
.site-head nav a[aria-current="page"] {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

/* ---------- hero ---------- */

.hero {
  padding: 70px 0 42px;
}

.hero h1 {
  grid-column: 1 / 9;
  margin: 0 0 26px;
  font-family: var(--sans);
  font-weight: 800;
  font-size: clamp(38px, 6.4vw, 74px);
  line-height: 0.98;
  letter-spacing: -0.035em;
}

.hero-intro {
  grid-column: 1 / 7;
}

.hero-intro p:last-child { margin-bottom: 0; }

.hero-index {
  grid-column: 10 / 13;
  grid-row: 1 / span 2;
  align-self: start;
}

.hero-index h2 {
  font-family: var(--sans);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--muted);
  margin: 6px 0 14px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--rule);
}

.hero-index ol {
  margin: 0;
  padding: 0;
  list-style: none;
  font-family: var(--sans);
  font-size: 13.5px;
  line-height: 1.4;
}

.hero-index li {
  display: flex;
  gap: 10px;
  margin-bottom: 11px;
}

.hero-index .num {
  color: var(--blue);
  font-weight: 700;
  font-size: 12px;
  padding-top: 1px;
  font-variant-numeric: tabular-nums;
}

.hero-index a {
  color: var(--ink);
  text-decoration: none;
  border-bottom: 1px solid rgba(26, 28, 34, 0.25);
}

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

/* ---------- main image ---------- */

.figure-main {
  margin: 0;
  padding: 10px 0 42px;
}

.figure-main img {
  grid-column: 1 / 9;
  display: block;
  width: 100%;
  height: auto;
}

.figure-main figcaption {
  grid-column: 10 / 13;
  align-self: end;
  font-family: var(--sans);
  font-size: 13px;
  line-height: 1.5;
  color: var(--muted);
}

/* ---------- sections ---------- */

.band { padding: 42px 0; }

.band--alt { background: var(--paper-alt); }

.band--dark {
  background: var(--ink);
  color: var(--paper);
  padding: 72px 0;
}

.body {
  grid-column: 1 / 8;
  border-top: 1px solid var(--rule);
  padding-top: 22px;
}

.rail {
  grid-column: 10 / 13;
  padding-top: 22px;
}

.band--dark .body { border-top-color: var(--rule-light); }

.body h2 {
  margin: 0 0 20px;
  font-family: var(--sans);
  font-weight: 800;
  font-size: clamp(25px, 3vw, 34px);
  line-height: 1.08;
  letter-spacing: -0.025em;
}

.body h3 {
  margin: 30px 0 8px;
  font-family: var(--sans);
  font-weight: 700;
  font-size: 19px;
  letter-spacing: -0.015em;
}

.body p {
  margin: 0 0 18px;
  max-width: 36em;
}

.body p:last-child { margin-bottom: 0; }

.rail .num {
  display: block;
  font-family: var(--sans);
  font-size: 12px;
  font-weight: 700;
  color: var(--blue);
  font-variant-numeric: tabular-nums;
  margin-bottom: 7px;
}

.band--dark .rail .num { color: #8fb0cf; }

.rail p {
  margin: 0 0 12px;
  font-family: var(--sans);
  font-size: 13px;
  line-height: 1.5;
  color: var(--muted);
}

.band--dark .rail p { color: #a6a39a; }

.rail a { color: var(--accent); }

.band--dark .rail a { color: #e2857f; }

/* lists */

.checklist {
  list-style: none;
  margin: 0 0 20px;
  padding: 0;
  max-width: 36em;
}

.checklist li {
  position: relative;
  padding-left: 22px;
  margin-bottom: 10px;
}

.checklist li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.62em;
  width: 8px;
  height: 8px;
  background: var(--accent);
}

.steps {
  counter-reset: step;
  list-style: none;
  margin: 0 0 20px;
  padding: 0;
  max-width: 36em;
}

.steps li {
  counter-increment: step;
  position: relative;
  padding-left: 34px;
  margin-bottom: 12px;
}

.steps li::before {
  content: counter(step, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 0.28em;
  font-family: var(--sans);
  font-size: 12px;
  font-weight: 700;
  color: var(--blue);
}

.band--dark .steps li::before { color: #8fb0cf; }

/* ---------- dark detail section ---------- */

.detail-fig {
  grid-column: 1 / 6;
  margin: 0;
  align-self: start;
}

.detail-fig img {
  display: block;
  width: 100%;
  height: auto;
}

.detail-fig figcaption {
  margin-top: 12px;
  font-family: var(--sans);
  font-size: 12.5px;
  line-height: 1.5;
  color: #a6a39a;
}

.detail-text {
  grid-column: 7 / 13;
  border-top: 1px solid var(--rule-light);
  padding-top: 22px;
}

.detail-text h2 {
  margin: 0 0 20px;
  font-family: var(--sans);
  font-weight: 800;
  font-size: clamp(25px, 3vw, 34px);
  line-height: 1.08;
  letter-spacing: -0.025em;
}

.detail-text h3 {
  margin: 30px 0 8px;
  font-family: var(--sans);
  font-weight: 700;
  font-size: 19px;
  letter-spacing: -0.015em;
}

.detail-text p { margin: 0 0 18px; max-width: 36em; }

.detail-text .secnum {
  display: block;
  font-family: var(--sans);
  font-size: 12px;
  font-weight: 700;
  color: #8fb0cf;
  margin-bottom: 10px;
  font-variant-numeric: tabular-nums;
}

/* ---------- inner pages ---------- */

.page-head { padding: 66px 0 8px; }

.page-head h1 {
  grid-column: 1 / 9;
  margin: 0 0 22px;
  font-family: var(--sans);
  font-weight: 800;
  font-size: clamp(34px, 5vw, 56px);
  line-height: 0.99;
  letter-spacing: -0.035em;
}

.page-head .lead {
  grid-column: 1 / 8;
  margin: 0;
  color: var(--muted);
}

.page-rail {
  grid-column: 10 / 13;
  grid-row: 1 / span 2;
  align-self: start;
  font-family: var(--sans);
  font-size: 13px;
  line-height: 1.5;
  color: var(--muted);
}

.page-rail ul {
  margin: 6px 0 0;
  padding: 0;
  list-style: none;
}

.page-rail li {
  padding: 9px 0;
  border-top: 1px solid var(--rule);
}

.page-rail li:first-child { border-top: none; padding-top: 0; }

/* ---------- footer ---------- */

.site-foot {
  padding: 56px 0 64px;
  background: var(--paper-alt);
}

.foot-top {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: baseline;
  gap: 18px 32px;
  padding-bottom: 22px;
}

.foot-name {
  font-family: var(--sans);
  font-weight: 800;
  font-size: 24px;
  letter-spacing: -0.03em;
}

.site-foot nav ul {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 22px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-family: var(--sans);
  font-size: 14.5px;
}

.site-foot nav a {
  color: var(--ink);
  text-decoration: none;
  border-bottom: 1px solid rgba(26, 28, 34, 0.25);
}

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

.foot-rule {
  border: 0;
  border-top: 1px solid var(--rule);
  margin: 0;
}

.foot-bottom {
  padding-top: 22px;
  font-family: var(--sans);
  font-size: 14px;
  line-height: 1.6;
  color: var(--muted);
  max-width: 60em;
}

.foot-bottom a { color: var(--accent); }

.foot-mail { margin: 0 0 10px; }

/* ---------- responsive ---------- */

@media (max-width: 1000px) {
  .hero h1 { grid-column: 1 / 10; }
  .hero-intro { grid-column: 1 / 9; }
  .body { grid-column: 1 / 9; }
  .page-head h1, .page-head .lead { grid-column: 1 / 10; }
  .figure-main img { grid-column: 1 / 10; }
  .detail-fig { grid-column: 1 / 6; }
  .detail-text { grid-column: 7 / 13; }
}

@media (max-width: 820px) {
  body { font-size: 17px; }

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

  .hero { padding: 40px 0 26px; }

  .hero h1,
  .hero-intro,
  .hero-index,
  .body,
  .rail,
  .page-head h1,
  .page-head .lead,
  .page-rail,
  .detail-fig,
  .detail-text,
  .figure-main img,
  .figure-main figcaption {
    grid-column: 1;
    grid-row: auto;
  }

  .hero-index,
  .rail,
  .page-rail { order: -1; }

  .hero-index { margin-bottom: 30px; }

  .hero-index ol {
    display: flex;
    flex-wrap: wrap;
    gap: 8px 18px;
  }

  .hero-index li { margin-bottom: 0; }

  .rail {
    padding-top: 0;
    margin-bottom: 14px;
  }

  .rail .num { display: inline; margin-right: 8px; }

  .rail p { display: inline; }

  .page-rail { margin-bottom: 28px; }

  .band { padding: 25px 0; }

  .band--dark { padding: 44px 0; }

  .detail-fig { margin-bottom: 26px; }

  .figure-main { padding: 4px 0 26px; }

  .figure-main figcaption { margin-top: 10px; }

  .detail-text { border-top: none; padding-top: 0; }

  .page-head { padding: 36px 0 4px; }

  .site-foot { padding: 40px 0 48px; }
}

@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; }
}