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

body {
    width: 100%;
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: black;
}

.container {
    border: 1px solid black;
    padding: 20px;
    border-radius: 15px;
    box-shadow: 0px 5px 20px red;
}

input {
    width: 320px;
    border: none;
    outline: none;
    padding: 15px;
    margin: 10px;
    background: gray;
    box-shadow: 0px 5px 15px red;
    font-size: 40px;
    text-align: right;
    cursor: pointer;
    color: white;
}

input::placeholder {
    color: white;
}

button {
    border: none;
    width: 60px;
    height: 55px;
    font-size: 24px;
    margin: 10px;
    border-radius: 50%;
    background-color: gray;
    color: white;
    cursor: pointer;
    box-shadow: 0px 5px 15px red;
}

.active {
    color: red;
    z-index: 10;
    background-color: yellow;
    box-shadow: inset 6px 6px 7px rgba(0, 0, 0, 0.08), 7px 8px 9px rgba(0, 0, 0, 0.08), 10px 15px 20px rgba(0, 0, 0, 0.08), inset -20px -20px 15px rgb(242, 255, 0);

}

.equal {
    color: white;
    background-color: blue;
    box-shadow: inset 6px 6px 7px rgba(0, 0, 0, 0.08), 7px 8px 9px rgba(0, 0, 0, 0.08), 10px 15px 20px rgba(0, 0, 0, 0.08), inset -20px -20px 15px rgba(0, 110, 255, 0.9);
}

.del {
    color: white;
    background-color: red;
    box-shadow: inset 6px 6px 7px rgba(0, 0, 0, 0.08), 7px 8px 9px rgba(0, 0, 0, 0.08), 10px 15px 20px rgba(0, 0, 0, 0.08), inset -20px -20px 15px rgba(239, 71, 71, 0.9);
}