* {
    box-sizing: border-box;
}

body {
    background: linear-gradient(to bottom right, #003366, #660033);
    margin: 0;
    font-size: 3em;
    margin: 0 5px;
}

.calc {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    grid-template-rows: repeat(6, 1fr);
    max-width: 1000px;
    min-height: 500px;
    height: calc(100vh - 100px);
    margin: 20px auto;
    border: 1px solid #000;
    box-shadow: 0 0 14px #000;
    user-select: none;
    background-color: rgb(78, 132, 134);
    border-radius: 15px;
    padding: 10px;
}

.calc_item {
    display: flex;
    justify-content: center;
    align-items: center;
    border: 1px solid #000;
    cursor: pointer;
    background-color: cadetblue;
    box-shadow: 2px 2px 2px #000, inset 0 0 0 #000;
    transition: 0.3s;
    color: #fff;
    font-weight: 700;
    font-family: sans-serif;
    text-shadow: 2px 2px 2px #000;
    border-radius: 40px;
    margin: 10px;
}

.calc_item:hover {
    box-shadow: 2px 2px 2px #000, inset 2px 2px 2px #000;
}

.calc_item:active {
    box-shadow: 2px 2px 2px #000, inset 4px 4px 4px #000;
    background-color: rgb(81, 138, 139);
}

.clac_item_span {
    grid-column: span 2;
}

.calc_input {
    grid-column: span 3;
    border-radius: 10px;
    background-color: rgb(212, 242, 242);
    padding: 5px;
    font-size: 50px;
}

.author {
    height: 60px;
    color: #ba2c81;
    font-family: Impact, Haettenschweiler, 'Arial Narrow Bold', sans-serif;
    text-shadow: 2px 2px 2px #000;
    margin-left: 10px;
}