style.css

.box {
    width: 800px !important;
    top: 50%;
    position: relative;
    transform: translateY(-50%); 
}

.operations {
    background-color: #deefef !important;
}

.line div {
    background-color: #F5F5F5; 
    color: black;
    padding: 16px 8px;
    text-align: center;
    text-decoration: none;
    display: inline-block;
    font-size: 16px;
    border: 0.1px solid #D3D3D3; 
    transition: all 0.1s;
    cursor: pointer;
    outline: none;
}

.line div:hover {
    background-color: #C0C0C0;
}

.ac {
    background-color: #90EE90 !important;
}

.igual {
    color: #D2122E !important;
}

input {
    width: 75%;
    height: 60px;
    border: 0.5px solid #D3D3D3;
    background-color: #fff;
    padding-left: 10px;
}

button {
    border: 0.1px solid #D3D3D3; 
}

@media (max-width: 480px) {
    .box {
        display: flex !important;
        width: 100% !important;
    }

    input {
        width: 100%;
        height: 75%;
        border: 0.5px solid #D3D3D3;
        background-color: #fff;
        padding-left: 10px;
    }

    .line div {
        background-color: #F5F5F5; 
        color: black;
        padding: 16px 8px;
    }
}