.preview-header{
    text-align:center;
    padding:60px 20px 30px;
}

.preview-header img{
    width:220px;
    border-radius:18px;
    box-shadow:0 10px 30px rgba(0,0,0,.15);
}

.back-btn{
    display:inline-block;
    margin-bottom:30px;
    text-decoration:none;
    color:var(--pink);
    font-weight:600;
}

.book{
    max-width:800px;
    margin:auto;
    padding:20px;
}

.page{
    display:none;
    background:#fffdf8;
    padding:50px;
    border-radius:20px;
    box-shadow:0 10px 35px rgba(0,0,0,.08);
    min-height:550px;
    text-align:center;
    line-height:1.9;
    font-size:1.1rem;
}

.page.active{
    display:block;
    animation:fade .4s;
}

.page h2{
    position:relative;
    margin:0 0 60px;
    text-align:center;
    font-size:2rem;
    color:#24314f;
}

.page h2::before{
    content:"";
    position:absolute;
    left:50%;
    bottom:-18px;
    transform:translateX(-50%);
    width:180px;
    height:2px;
    background:linear-gradient(
        to right,
        var(--pink) 0%,
        var(--pink) 42%,
        transparent 42%,
        transparent 58%,
        var(--pink) 58%,
        var(--pink) 100%
    );
}

.page h2::after{
    content:"❤";
    position:absolute;
    left:50%;
    bottom:-28px;
    transform:translateX(-50%);
    background:#fffdf8;
    color:var(--pink);
    padding:0 10px;
    font-size:18px;
}

.page img{
    display:block;
    margin:0 auto;
    max-width:100%;
    height:auto;
    border-radius:12px;
}

.page p{
    max-width:650px;
    margin:35px auto 0;
    text-align:left;
}

.controls{
    margin-top:30px;
    display:flex;
    justify-content:space-between;
    align-items:center;
}

.controls button{
    padding:12px 20px;
    border:none;
    background:var(--pink);
    color:white;
    border-radius:30px;
    cursor:pointer;
    font-size:16px;
    transition:.2s;
}

.controls button:hover{
    background:var(--pink-dark);
    transform:translateY(-2px);
}

.controls button:disabled{
    opacity:.5;
    cursor:default;
    transform:none;
}

@keyframes fade{
    from{
        opacity:0;
        transform:translateY(15px);
    }

    to{
        opacity:1;
        transform:none;
    }
}