* {
    margin: 0;
    padding: 0;
    font-family: sans-serif;
    font-weight: bold;
    box-sizing: border-box;
}

body {
    width: 100%;
    padding-top: 10rem;
    height: 80vh;
    display: flex;
    justify-content: center;
    align-items: center;
    background-color: #2b3b3d;
    background-position: center;
    background-repeat: no-repeat;
    background-size: cover;
}

.calculator {
    padding: 20px;
    border: 2px solid #000;
    border-radius: 16px;
    box-shadow: 0px 3px 15px rgba(0,0,0,0.8);
    background: rgba(0,0,0,0.5);
}

input {
    width: 322px;
    padding: 24px;
    margin: 10px;
    background: rgba(255,255,255,0.3);
    box-shadow: inset 0px 0px 8px rgba(0,0,0,0.4);
    text-align: right;
    font-size: 65px;
    color: #fff;
    border: solid 2px rgba(0,0,0,0.4);
    border-radius: 16px;
    text-shadow: 0px 1px 5px rgba(0,0,0,0.2);
}

input::placeholder {
    color: #fff;
}

button {
    width: 60px;
    height: 60px;
    margin: 10px;
    color: #fff;
    background: rgba(0,0,0,0.7);
    font-size: 24px;
    cursor: pointer;
    border: solid 1px rgba(255,255,255,0.2);
    border-radius: 22px;
    text-shadow: 0px 1px 5px rgba(0,0,0,0.2);
    box-shadow: -1px 2px 10px rgba(0,0,0,0.5);
}

.ac, .del {
    font-size: 20px;
}

button:hover {
    color: #fff;
    background: #78A8B0;
}

.equal_Btn {
    background: #78A8B0;
}

.operator {
    color: #78A8B0;
}