main{
    min-height: 100vh;
}
h2 + p{
    font-size: 12px;
}
.heading-2{
    margin-top: 0 !important;
    padding: 5px;
}   
.heading-4{
    font-weight: bold ;
}

.nav{
    visibility: hidden;
}

form{
    width: 100%;
    max-width: 900px;
    display: flex;
    flex-direction: column;
    margin: 0 auto;
}

.input-box input{
    width: 100%;
    border: none;
    outline: none;
    border-bottom: 1px solid var(--border-color);
    font-size: 1.3em;
    padding: 8px 0;
}

.input-box::before{
    content: "";
    position: absolute;
    display: block;
    width: 0px;
    height: 3px;
    bottom: 0; left: 50%;
    transform: translate(-50%, -50%);
    background: var(--primary-color);
    transition: all .3s ease-in-out;
}
.input-box:has(input:focus)::before{
    width: 100%;
    transition: all .3s ease-in-out;
}

form .input-box label{
    position: absolute;
    left: 0;
    bottom: 8px;
    color: var(--secondary-color);
    font-size: 16px;
}

form .input-box input:focus + label,
form .input-box input:valid + label{
    transform: translateY(-120%);
    color: var(--primary-color);
    font-size: 1em;
}

form .input-box select{
    width: 100%;
    font-size: 16px;
    background: none;
    outline: none;
    width: 100%;
    border: none;
    border-bottom: 1px solid var(--border-color);
    padding: 8px 0;
    color: var(--secondary-color);
}
form .input-box select + label{
    position: absolute;
    transform: translateY(-150%);
    color: var(--primary-color);
    font-size: 1em;
}

form .subsection .row:not(:has(#setBilling:checked)) + .bill-address{
    display: none;
}

.row{
    justify-content: flex-start;
}


.column{
    display: flex;
    flex-direction: column;
    gap: 2em;
    width: 100%;
    padding: .5em 2em;
}

.subsection{
    display: flex;
    flex-direction: column;
    gap: 2.3em;
}

.subsection .flex{
    gap: 1em;
}

.input-box{
    position: relative;
    width: 100%;
    padding: .2em 0;
}

.subsection.order-summary{
    gap: 1em;
}

.subsection.order-summary ul li{
    padding: .2em 0;
}

.grand-total{
    padding-top: 1.5em ;
}

.column .btn{
    position: fixed;
    bottom: 0; left: 0;
    width: 100vw;
    background: var(--accent-color);
    padding: 1.5em;
    font-weight: 500;
    color: white;
    text-align: center;
}

.order-summary{
    margin-bottom: 5em;
}

@media (min-width: 768px){
    form{
        flex-direction: row;
        margin: 3em auto;
        margin-bottom: 5em;
        gap: 6em;
    }
    .column{
        padding: 0em 0;
    }
    .column .btn{
        position: relative;
        border: 2px solid var(--primary-color);
        color: var(--primary-color);
        width: fit-content;
        background: white;
        padding: 10px 44px;
        font-size: 14px;
        cursor: pointer;
    }
    .order-summary{
        margin-bottom: 0;
    }
}