:root {
  --bg: #ffffff;
  --fg: #111111;
  --muted: #6b6b6b;
  --line: #e5e5e5;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b0b0b;
    --fg: #f1f1f1;
    --muted: #9a9a9a;
    --line: #2a2a2a;
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  height: 100%;
  background: var(--bg);
  color: var(--fg);
  font: 16px/1.3 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, system-ui, sans-serif;
  -webkit-font-smoothing: antialiased;
}

main {
  padding: max(env(safe-area-inset-top), 24px) 20px max(env(safe-area-inset-bottom), 24px);
  display: flex;
  flex-direction: column;
  gap: 16px;
  max-width: 480px;
  margin: 0 auto;
}

.row {
  position: relative;
  display: flex;
  align-items: baseline;
  font-size: 56px;
  font-weight: 300;
  letter-spacing: -0.02em;
}

input#czk {
  flex: 1;
  min-width: 0;
  width: 100%;
  font: inherit;
  color: inherit;
  background: transparent;
  border: 0;
  border-bottom: 1px solid var(--line);
  outline: none;
  padding: 8px 0;
  -webkit-appearance: none;
  appearance: none;
}
input#czk::placeholder { color: var(--muted); }
input#czk:focus { border-bottom-color: var(--fg); }

.suffix {
  margin-left: 12px;
  color: var(--muted);
  font-size: 32px;
}

.out {
  color: var(--muted);
  padding: 8px 0;
  font-variant-numeric: tabular-nums;
}