.age-calc-box {
  max-width: 350px;
  padding: 20px;
  margin: 20px auto;
  border-radius: 12px;
  background: #f5f5f5;
  text-align: center;
  box-shadow: 0 4px 8px rgba(0,0,0,0.1);
}
.age-calc-box.dark-mode {
  background: #222;
  color: #fff;
}
.age-calc-box input, button {
  margin: 6px;
  padding: 8px;
  border-radius: 6px;
}
.actions button {
  margin: 4px;
  cursor: pointer;
}