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

body{
    font-family:"Times New Roman", serif;
    background:white;
}

.calculator{

    width:680px;
    margin:40px auto;
    background:#b9dceb;
    padding:25px;
}

.calculator h1{

    text-align:center;
    font-size:36px;
    margin-bottom:30px;
}

table{

    width:100%;
    border-collapse:collapse;
}

td{

    padding:18px 0;
}

.label{

    width:220px;
    font-size:28px;
}

input[type=text]{

    width:390px;
    height:40px;
    border:1px solid gray;
    font-size:22px;
    padding-left:8px;
}

.buttons{

    white-space:nowrap;
}

.buttons input{

    width:70px;
    height:38px;
    margin-right:8px;
    font-size:16px;
    cursor:pointer;
}
.back{
    text-align:center;
    margin:35px 0;
}

.back a{

    display:inline-block;

    padding:12px 25px;

    background:linear-gradient(135deg,#4CAF50,#2E8B57);

    color:white;

    text-decoration:none;

    border-radius:30px;

    font-size:18px;

    font-weight:bold;

    box-shadow:0 5px 10px rgba(0,0,0,.2);

    transition:.3s;
}

.back a:hover{

    background:linear-gradient(135deg,#2E8B57,#4CAF50);

    transform:translateY(-3px);

    box-shadow:0 8px 18px rgba(0,0,0,.3);
}