:root {
  color-scheme: light dark;
  --background: #f5f5f5;
  --text: #171717;
  --muted: #676767;
  --line: #dddddd;
  --button: #171717;
  --button-text: #ffffff;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--background);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Helvetica Neue", sans-serif;
  font-size: 16px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

main {
  width: min(720px, calc(100% - 32px));
  margin: 0 auto;
  padding: 64px 0;
}

header {
  display: flex;
  align-items: center;
  gap: 18px;
}

.app-icon { border-radius: 20px; }

h1 {
  margin: 0;
  font-size: 42px;
  letter-spacing: -.04em;
  line-height: 1;
}

.tagline {
  margin: 8px 0 0;
  color: var(--muted);
  font-size: 17px;
}

.intro { margin: 30px 0 0; }

nav {
  display: flex;
  align-items: center;
  gap: 18px;
  margin: 24px 0 36px;
}

nav a {
  color: var(--text);
  font-weight: 600;
  text-underline-offset: 3px;
}

nav .download {
  padding: 9px 15px;
  border-radius: 8px;
  background: var(--button);
  color: var(--button-text);
  text-decoration: none;
}

.demo {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--line);
  border-radius: 12px;
}

section { margin-top: 42px; }

h2 {
  margin: 0 0 14px;
  font-size: 22px;
}

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

li + li { margin-top: 10px; }

.requirements {
  padding-top: 28px;
  border-top: 1px solid var(--line);
}

@media (prefers-color-scheme: dark) {
  :root {
    --background: #111111;
    --text: #f2f2f2;
    --muted: #a3a3a3;
    --line: #333333;
    --button: #f2f2f2;
    --button-text: #111111;
  }
}

@media (max-width: 520px) {
  main { padding: 40px 0; }
  .app-icon { width: 72px; height: 72px; border-radius: 16px; }
  h1 { font-size: 36px; }
  .tagline { font-size: 15px; }
}