body{
    background-image: url(./image/pexels-nirbito-ninar-20722851.jpg);
    background-repeat: no-repeat;
    background-size: cover;
}
.container {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    grid-gap: 5px;
    padding: 10px;
    max-width: 500px;
    margin: 0 auto;
    top: 50%;
    left: 50%;
    transform: translate(-50%, 50%);
}

button {
    padding: 10px;
    font-size: 1.2em;
    border: none;
    border-radius: 5px;
    background-color: black;
    color: white;
    cursor: pointer;
   
}

button:hover {
    background-color: #ccc;
}

input[type="text"] {
    grid-column: span 4;
    padding: 26px;
    font-size: 1.2em;
    text-align: right;
    border: 1px solid #ccc;
    border-radius: 5px;
    margin-bottom: 10px;
    outline: none;
    background-color: black;
    color: white;
}
.equal-btn {
    background-color: gray;
}
#ops{
    background-color: orange;
}