:root {
  --bg: #ffffff;
  --text: #000000;
  --muted: #555555;
  --line: #000000;
  --soft-line: #dddddd;
  --font: "Helvetica Neue", Helvetica, Arial, sans-serif;
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #000000;
    --text: #ffffff;
    --muted: #aaaaaa;
    --line: #ffffff;
    --soft-line: #333333;
  }
}

* { box-sizing: border-box; }

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 17px/1.6 var(--font);
}

a { color: var(--text); text-underline-offset: 3px; }

.wrap {
  max-width: 720px;
  margin: 0 auto;
  padding: 0 20px;
}

header.site {
  padding: 18px 0;
  border-bottom: 1px solid var(--line);
}

header.site .wrap {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}

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

header.site nav { display: flex; align-items: center; gap: 18px; font-size: 15px; }

header.site nav a.lang { color: var(--muted); text-decoration: none; }
header.site nav a.lang:hover { color: var(--text); }

/* App menu: a <details> dropdown, so it works on tap and keyboard without JS. */
.menu { position: relative; }

.menu summary {
  display: flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
  list-style: none;
  user-select: none;
}

.menu summary::-webkit-details-marker { display: none; }

.menu summary::after {
  content: "";
  width: 6px;
  height: 6px;
  border-right: 1.5px solid currentColor;
  border-bottom: 1.5px solid currentColor;
  transform: translateY(-2px) rotate(45deg);
  transition: transform 0.15s;
}

.menu[open] summary::after { transform: translateY(1px) rotate(-135deg); }

.menu ul {
  position: absolute;
  right: 0;
  top: calc(100% + 12px);
  z-index: 10;
  min-width: 160px;
  margin: 0;
  padding: 6px 0;
  list-style: none;
  background: var(--bg);
  border: 1px solid var(--line);
}

.menu ul a {
  display: block;
  padding: 8px 16px;
  color: var(--text);
  text-decoration: none;
}

.menu ul a:hover { background: var(--text); color: var(--bg); }
.menu ul a[aria-current] { font-weight: 700; }

main { padding: 56px 0 72px; }

h1, h2, h3 { font-weight: 700; line-height: 1.15; letter-spacing: -0.01em; }
h1 { font-size: clamp(36px, 7vw, 56px); margin: 0 0 12px; letter-spacing: -0.03em; }
h2 { font-size: 24px; margin: 48px 0 8px; }
h3 { font-size: 18px; margin: 28px 0 4px; }

.lede { font-size: 20px; color: var(--muted); margin: 0 0 28px; }
.meta { color: var(--muted); font-size: 15px; }

.hero { text-align: center; padding: 8px 0 24px; }
.hero img.icon {
  width: 160px;
  height: 160px;
  border-radius: 36px;
  border: 1px solid var(--soft-line);
  margin-bottom: 28px;
}

.badge {
  display: inline-block;
  border: 1px solid var(--line);
  padding: 8px 18px;
  border-radius: 999px;
  font-size: 15px;
}

.features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 0;
  margin: 56px 0 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line);
}

.features li {
  padding: 20px 20px 24px 0;
  border-bottom: 1px solid var(--soft-line);
}

.features h3 { margin: 0 0 6px; font-size: 17px; }
.features p { margin: 0; color: var(--muted); font-size: 15px; }

.app-card {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-top: 40px;
  padding: 20px 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  color: var(--text);
  text-decoration: none;
}

.app-card img { width: 64px; height: 64px; border-radius: 14px; border: 1px solid var(--soft-line); }
.app-card strong { display: block; font-size: 19px; }
.app-card span { color: var(--muted); font-size: 15px; }

.summary {
  border: 1px solid var(--line);
  padding: 16px 20px;
  margin: 24px 0;
}

.summary ul { margin: 0; padding-left: 20px; }

footer.site {
  border-top: 1px solid var(--line);
  padding: 24px 0 40px;
  color: var(--muted);
  font-size: 14px;
}

footer.site .wrap { display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; }
footer.site a { color: var(--muted); }