:root {
  color-scheme: dark;
  --bg: #070b12;
  --card: #101722;
  --line: #2a3a52;
  --text: #f4f7fb;
  --muted: #d5deec;
  --accent: #9be7ff;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  background: var(--bg);
}

body {
  margin: 0;
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  background: var(--bg);
  color: var(--text);
  font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", "PingFang SC", "Hiragino Sans GB", "Noto Sans CJK SC", "Microsoft YaHei", sans-serif;
  font-size: 1.0625rem;
  line-height: 1.5;
}

main {
  flex: 1;
  width: min(100% - 2rem, 36rem);
  margin: 12vh auto 0;
  padding: 1.75rem 1.25rem 1.5rem;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: var(--card);
}

h1 {
  margin: 0;
  font-size: 1.75rem;
  font-weight: 600;
  letter-spacing: -0.03em;
  line-height: 1.15;
}

h1 a {
  color: inherit;
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 0.18em;
}

h1 a:hover {
  color: var(--accent);
}

h1 a:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

.lead,
.note {
  margin: 1.25rem 0 0;
}

.lead {
  font-size: 1.25rem;
  color: var(--text);
}

.note {
  color: var(--muted);
}

.mark {
  display: block;
  width: 2.5rem;
  height: 0.2rem;
  margin-bottom: 1.25rem;
  border-radius: 999px;
  background: var(--accent);
}

footer {
  width: min(100% - 2rem, 36rem);
  margin: 0 auto;
  padding: 1rem 0 2rem;
  color: var(--muted);
  font-size: 0.875rem;
}

@media (min-width: 40rem) {
  main {
    margin-top: 18vh;
    padding: 2.25rem 2rem 2rem;
  }

  h1 {
    font-size: 2.25rem;
  }
}