:root {
  color-scheme: light dark;
}
body {
  font-family: system-ui, sans-serif;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  margin: 0;
  gap: 2rem;
  background: #0f172a;
  color: #f1f5f9;
}
h1 {
  font-weight: 600;
  font-size: 1.25rem;
  opacity: 0.8;
}
.pair {
  display: flex;
  gap: 2rem;
}
button.num {
  font-size: 3rem;
  padding: 2rem 3rem;
  border-radius: 1rem;
  border: 2px solid #334155;
  background: #1e293b;
  color: #f1f5f9;
  cursor: pointer;
  transition:
    transform 0.1s ease,
    border-color 0.1s ease;
  min-width: 8rem;
}
button.num:hover {
  border-color: #38bdf8;
  transform: scale(1.03);
}
button.num:active {
  transform: scale(0.97);
}
button.num:disabled {
  opacity: 0.5;
  cursor: default;
}
#status {
  min-height: 1.5rem;
  opacity: 0.7;
  font-size: 0.9rem;
}
#count {
  opacity: 0.5;
  font-size: 0.8rem;
}