*{
    box-sizing: border-box;
}

body{
    margin: 0;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
}

.calculator{
    width: 400px;
    background-color: black;
    color: white;
}

.screen{
    color: white;
    font-size: 40px;
    font-family: 'Courier New', Courier, monospace;
    text-align: right;
    padding: 20px 5px;
}

.calc-button{
    background-color: #d8d9db;
    color: black;
    height: 100px;
    width: 24.5%;
    border: none;
    border-radius: 0;
    font-size: 40px;
    cursor: pointer;
    text-align: center;
}

.calc-button:hover{
    background-color: #ebebeb;
}

.calc-button:active{
    background-color: #bbbcbe;
}

.double{
    width: 49.7%;
}

.triple{
    width: 74.8%;
}

.calc-button:last-child{
    background-color: #df974c;
    color: white;
}
.calc-button:last-child:hover{
    background-color: #dfb07e;
}
.calc-button:last-child:active{
    background-color: #dd8d37;
}
.calc-button-row{
    display: flex;
    align-content: stretch;
    justify-content: space-between;
    margin-bottom: 0.5%;
}
.calc-button-row:last-child{
    padding-bottom: 0;
}

@media (max-width: 1024px){
    .calculator{
        width: 360px;
    }

    .calc-button{
        height: 90px;
        font-size: 36px;
    }

    .screen{
        font-size: 36px;
    }
}

@media (max-width: 768px){
    body{
        padding: 10px;
    }
    .calculator{
        width: 100%;
        max-width: 360px;
    }
    .calc-button{
        height: 80px;
        font-size: 32px;
    }

    .screen{
        font-size: 32px;
        padding: 15px 15px;
    }
}

@media (max-width: 480px){
    .calculator{
        max-width: 320px;
    }
    .calc-button{
        height: 70px;
        font-size: 28px;
    }
    .screen{
        font-size: 28px;
        padding: 12px 15px;
    }
}

@media (max-width: 360px){
    .calculator{
        max-width: 280px;
    }

    .calc-button{
        height: 60px;
        font-size: 24px;
    }

    .screen{
        font-size: 24px;
    }
}