:root {
  color-scheme: light dark;
  --background: #f3f5f7;
  --surface: #ffffff;
  --text: #202124;
  --muted: #5f6368;
  --border: #d8dde3;
  --accent: #2458a6;
  --accent-hover: #183f7c;
  --accent-text: #ffffff;
  --notice: #eef4fc;
}

@media (prefers-color-scheme: dark) {
  :root {
    --background: #17191c;
    --surface: #22252a;
    --text: #f2f3f5;
    --muted: #b9bec6;
    --border: #3b414a;
    --accent: #8ab4f8;
    --accent-hover: #aecbfa;
    --accent-text: #111315;
    --notice: #202b39;
  }
}

* {
  box-sizing: border-box;
}

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

body {
  margin: 0;
  background: var(--background);
  color: var(--text);
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    Roboto, Helvetica, Arial, sans-serif;
  font-size: 18px;
  line-height: 1.55;
}

header {
  border-bottom: 1px solid var(--border);
  background: var(--surface);
}

header .inner,
main,
footer {
  width: min(100% - 28px, 860px);
  margin-inline: auto;
}

header .inner {
  padding: 28px 0 24px;
}

main {
  padding: 28px 0 44px;
}

footer {
  padding: 0 0 40px;
  color: var(--muted);
  font-size: 0.92rem;
}

h1,
h2,
h3 {
  line-height: 1.2;
}

h1 {
  margin: 0 0 10px;
  font-size: clamp(1.8rem, 6vw, 2.5rem);
}

h2 {
  margin: 30px 0 16px;
  font-size: clamp(1.3rem, 4vw, 1.65rem);
}

h3 {
  margin: 0 0 8px;
  font-size: 1.28rem;
}

p {
  margin: 0 0 16px;
}

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

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

.intro,
.meta {
  color: var(--muted);
}

.grid {
  display: grid;
  gap: 20px;
}

.card,
.instructions,
.notice {
  border: 1px solid var(--border);
  border-radius: 14px;
  background: var(--surface);
}

.card {
  overflow: hidden;
}

.card .content {
  padding: 18px;
}

.instructions,
.notice {
  padding: 18px 20px;
}

.notice {
  margin: 22px 0;
  background: var(--notice);
}

.instructions ol {
  margin: 0;
  padding-left: 1.35rem;
}

.instructions li {
  margin-bottom: 10px;
}

.instructions li:last-child {
  margin-bottom: 0;
}

.meta {
  margin-bottom: 12px;
  font-size: 0.94rem;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 11px 16px;
  border-radius: 10px;
  background: var(--accent);
  color: var(--accent-text);
  font-weight: 650;
  text-decoration: none;
}

.button:hover,
.button:focus-visible {
  background: var(--accent-hover);
  color: var(--accent-text);
}

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

@media (max-width: 520px) {
  body {
    font-size: 17px;
  }

  header .inner,
  main,
  footer {
    width: min(100% - 20px, 860px);
  }

  header .inner {
    padding-top: 22px;
  }

  main {
    padding-top: 22px;
  }

  .card .content,
  .instructions,
  .notice {
    padding: 16px;
  }

  .button {
    width: 100%;
  }
}