.calculator {
  width: 300px;
  margin: 24px auto;
  background: #fff;
  box-shadow: 0 12px 50px -11px rgba(0, 0, 0, 0.2);
  border-radius: 8px;
  font-family: "Roboto", sans-serif;
  overflow: hidden;
}

.calculator .output {
  background: #14213d;
  color: #fff;
  padding: 32px;
}

.calculator .output input[type="text"] {
  font-size: 20px;
  padding: 8px 24px;
  width: 100%;
  color: #fff;
  background: transparent;
  border: none;
}

.calculator .actions {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: 8px;
  padding: 16px;
}

.calculator .btn {
  font-size: 18px;
  padding: 8px;
  width: 100%;
}

.calculator .btn-op {
  background: #e63946;
  color: #fff;
}

@media (max-width: 650px) {
  .calculator {
    width: 90%;
    max-width: 500px;
  }

  .calculator .actions {
    grid-template-columns: repeat(4, 1fr);
  }
}