body{
    margin: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
     background-color: hsl(0, 7%, 95%);

}



#Calculator{
    font-family: Arial, Helvetica, sans-serif;
    background-color: hsl(0, 0%, 6%);
    border-radius: 15px;
    max-width: 500px;
    overflow: hidden;
}

#display {
  width: 100%;
  padding: 20px;
  font-size: 3rem;
  text-align: right;
  border: none;
  outline: none;
  background-color: hsl(0, 0%, 10%);
  color: white;
  box-sizing: border-box;
}


#keys{
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
    padding: 25px;
}


button{

    width: 100px;
    height: 100px;
    border-radius: 50px;
    border: none;
    background-color: hsl(0, 0%, 42%);
    color: white;
    font-size: 3rem;
    font-weight: bold;
    cursor: pointer;
}

button:hover{
    background-color: hsl(0, 0%, 40%);
}
button:active{
    background-color: hsl(0, 0%, 50%);
}
.operator-btn{
     background-color: hsl(37, 83%, 47%);
}
.operator-btn:hover{
   background-color: hsl(37, 83%, 80%);
}
.operator-btn:active{
    background-color: hsl(37, 83%, 90%);

}


/* 📱 Responsive Adjustments */
@media (max-width: 600px) {
  #calculator {
    width: 95%;
    max-width: 320px;
  }

  #display {
    font-size: 2rem;
    padding: 15px;
  }

  button {
    font-size: 1.4rem;
    border-radius: 50%;
  }

  #keys {
    gap: 8px;
    padding: 15px;
  }
}

/* 🧾 Very Small Screens (Phones under 360px) */
@media (max-width: 400px) {
  #calculator {
    width: 95%;
    max-width: 280px;
  }

  #display {
    font-size: 1.6rem;
    padding: 12px;
  }

  button {
    font-size: 1.2rem;
  }
}