body{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    background-color: rgb(56, 216, 221);
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
}

#tl-pr{
    margin-right: 200px;
    font-size: 78px;
}

#bd-pr{
    background-color: rgb(41, 41, 41);
    max-width: 360px;
    border-radius: 10px;
    padding: 20px;
    box-shadow: 0 10px 20px;
}

#ds-pr{
    height: 56px;
    margin-bottom: 15px;
    border-radius: 5px;
    background-color: black;
    color: white;
    border: none;
    font-size: 20px;
    text-align: right;
}

button{
    width: calc(25% - 10px);
    height: 35px;
    font-size: 20px;
    margin: 10px 5px;
    border: none;
    border-radius: 5px;
    float: left;
    background-color: black;
    color: white;
    box-shadow: -1px 1px 30px -5px black;
}

button:hover{
    cursor: pointer;
}

button:active{
    transform: scale(1.05);
    box-shadow: 0 24px 4px 1px rgb(0, 0, 0, 0.19),
    0 1.5px 1.5px rgb(0, 0, 0, 0.24);
}

.operator{
    color:rgb(23, 58, 216);
}

#ac{
    color:red;
}

.eq-pr{
    width: calc(50% - 10px);
}