:root { --hue: 260; }

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  place-items: center;
  font-family: system-ui, sans-serif;
  background: linear-gradient(135deg, hsl(var(--hue) 80% 60%), hsl(calc(var(--hue) + 60) 80% 55%));
  transition: background .6s;
}

.card {
  background: rgba(255, 255, 255, .92);
  padding: 2.5rem 3rem;
  border-radius: 1.5rem;
  text-align: center;
  box-shadow: 0 20px 50px rgba(0, 0, 0, .25);
  animation: pop .6s ease;
}

h1 { margin: 0 0 .5rem; font-size: 2.5rem; }

.teller { display: flex; justify-content: center; align-items: center; gap: 1.5rem; margin: 1.5rem 0; }
.teller span { font-size: 2.5rem; min-width: 3ch; font-weight: 700; }

button {
  border: 0;
  border-radius: 50%;
  width: 3rem;
  height: 3rem;
  font-size: 1.6rem;
  cursor: pointer;
  color: #fff;
  background: hsl(var(--hue) 70% 50%);
  transition: transform .15s;
}
button:hover { transform: scale(1.12); }
button:active { transform: scale(.95); }

button.groot { width: auto; height: auto; border-radius: 2rem; padding: .7rem 1.4rem; font-size: 1rem; }

#klok { color: #666; margin-bottom: 0; }

@keyframes pop { from { transform: scale(.8); opacity: 0; } }