:root {
  color-scheme: light;
  --bg: #f5f7fb;
  --surface: #ffffff;
  --ink: #172033;
  --muted: #5f6b7a;
  --line: #dbe3ee;
  --brand: #1f5fbf;
  --brand-dark: #173f83;
  --accent: #0b8f6f;
  --warning: #9a5b0b;
  --shadow: 0 18px 45px rgba(23, 32, 51, 0.1);
}

* {
  box-sizing: border-box;
}

html {
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.5;
  color: var(--ink);
  background: var(--bg);
}

body {
  margin: 0;
}

a {
  color: var(--brand);
  font-weight: 700;
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.hero {
  background:
    linear-gradient(135deg, rgba(31, 95, 191, 0.95), rgba(11, 143, 111, 0.9)),
    url("icons/Icon-192.png") center right 12% / 220px no-repeat;
  color: #ffffff;
  padding: 30px 20px 72px;
}

.nav,
.hero-inner,
.content,
.footer {
  width: min(1080px, calc(100% - 40px));
  margin: 0 auto;
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 56px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: inherit;
  font-size: 18px;
  font-weight: 800;
}

.brand-mark {
  display: grid;
  width: 42px;
  height: 42px;
  place-items: center;
  border: 1px solid rgba(255, 255, 255, 0.38);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.16);
  font-weight: 900;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 14px;
  flex-wrap: wrap;
}

.nav-links a {
  color: rgba(255, 255, 255, 0.88);
  font-size: 14px;
}

.eyebrow {
  display: inline-flex;
  min-height: 30px;
  align-items: center;
  padding: 4px 10px;
  border: 1px solid rgba(255, 255, 255, 0.34);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.12);
  font-size: 13px;
  font-weight: 700;
}

h1 {
  max-width: 760px;
  margin: 18px 0 14px;
  font-size: clamp(38px, 7vw, 68px);
  line-height: 0.98;
  letter-spacing: 0;
}

.hero-copy {
  max-width: 690px;
  margin: 0;
  color: rgba(255, 255, 255, 0.9);
  font-size: 18px;
}

.content {
  display: grid;
  grid-template-columns: 260px minmax(0, 1fr);
  gap: 28px;
  align-items: start;
  margin-top: -42px;
  padding-bottom: 54px;
}

.toc,
.article {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  box-shadow: var(--shadow);
}

.toc {
  position: sticky;
  top: 18px;
  padding: 18px;
}

.toc strong {
  display: block;
  margin-bottom: 10px;
  font-size: 14px;
}

.toc a {
  display: block;
  padding: 8px 0;
  border-top: 1px solid #eef2f7;
  color: var(--muted);
  font-size: 14px;
  font-weight: 650;
}

.article {
  padding: 34px;
}

.summary {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  margin-bottom: 30px;
}

.summary-item {
  min-height: 100px;
  padding: 16px;
  border: 1px solid #e6ecf4;
  border-radius: 8px;
  background: #f8fafd;
}

.summary-item strong {
  display: block;
  margin-bottom: 6px;
}

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

section {
  padding: 26px 0;
  border-top: 1px solid #edf1f6;
}

section:first-of-type {
  border-top: 0;
  padding-top: 0;
}

h2 {
  margin: 0 0 12px;
  font-size: 24px;
  line-height: 1.2;
  letter-spacing: 0;
}

p,
li {
  color: var(--muted);
}

p {
  margin: 0 0 12px;
}

ul,
ol {
  margin: 10px 0 0;
  padding-left: 22px;
}

li + li {
  margin-top: 8px;
}

.notice {
  margin: 18px 0;
  padding: 16px;
  border-left: 4px solid var(--accent);
  border-radius: 8px;
  background: #edf9f6;
  color: #17493f;
}

.warning {
  border-left-color: var(--warning);
  background: #fff7e8;
  color: #58370f;
}

.steps {
  counter-reset: step;
  list-style: none;
  padding-left: 0;
}

.steps li {
  position: relative;
  min-height: 48px;
  padding: 0 0 0 62px;
}

.steps li::before {
  counter-increment: step;
  content: counter(step);
  position: absolute;
  left: 0;
  top: 0;
  display: grid;
  width: 42px;
  height: 42px;
  place-items: center;
  border-radius: 8px;
  background: var(--brand);
  color: #ffffff;
  font-weight: 800;
}

.footer {
  padding: 0 0 34px;
  color: var(--muted);
  font-size: 14px;
}

@media (max-width: 820px) {
  .hero {
    padding-bottom: 56px;
    background:
      linear-gradient(135deg, rgba(31, 95, 191, 0.95), rgba(11, 143, 111, 0.9)),
      url("icons/Icon-192.png") center bottom 18px / 140px no-repeat;
  }

  .nav {
    align-items: flex-start;
    flex-direction: column;
    margin-bottom: 44px;
  }

  .content {
    display: block;
    margin-top: -30px;
  }

  .toc {
    position: static;
    margin-bottom: 18px;
  }

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

  .article {
    padding: 24px 18px;
  }
}