* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}


body {
  height: 100vh;
  background-color:#9091a5ef ;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  display: flex;
  justify-content: center;
  align-items: center;
  
  
}


.calculator {
  width: 320px;
  background-color: rgba(174, 192, 194, 0.957);
  border-radius: 40px;
  padding: 30px;
  margin: 40px;
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.1);
  transition: all 0.3s ease-in-out;
}

.calculator:hover {
  transform: scale(1.02);
}


#display {
  height: 60px;
  font-size: 2rem;
  border: 2px solid black;
  border-radius: 10px;
  padding-right: 10px;
  background-color: rgb(145, 205, 41);
  box-shadow: inset 0 1px 2px rgba(0,0,0,0.1);
}


.buttons .d-flex {
  gap: 10px;
  margin-bottom: 10px;
}


button {
  font-size: 1.2rem;
  height: 60px;
  border-radius: 12px !important;
  border: none;
  transition: background-color 0.2s ease;
}


button:hover {
  filter: brightness(90%);
  cursor: pointer;
}


.btn-warning {
  background-color: #ffca2c;
  color: #000;
  font-weight: bold;
}


.btn-success {
  background-color: #40c55f;
  color: white;
  font-weight: bold;
}


.btn-danger {
  background-color:  rgb(182, 45, 17);
  color: white;
  font-weight: bold;
}


.btn-secondary {
  background-color: rgb(204, 214, 213);
  color: white;
}


.btn-light {
  background-color: rgba(245, 239, 236, 0.895);
  color: #000;
}


@media (max-width: 400px) {
  .calculator {
    width: 95%;
    padding: 15px;
  }

  button {
    height: 55px;
    width: 40px;
    font-size: 1.1rem;
  }

  #display {
    font-size: 1.4rem;
    height: 50px;
  }
}