body{
    margin:0;
    height:100vh;
    background:#f7eef3;
    font-family:"Curlz MT";
}

/* BOOK */
.book{
    width:420px;
    height:520px;

    position:absolute;
    top:50%;
    left:50%;
    transform:translate(-50%,-50%);
}
/* PAGE */
.page{
    position:absolute;
    width:100%;
    height:100%;

    background:white;
    border:2px solid #e8dfe5;
    border-radius:18px;

    padding:20px;

    opacity:0;
    transform:translateX(40px) rotateY(10deg);
    transition:0.6s ease;

    box-shadow:0 10px 20px rgba(0,0,0,0.1);
}

/* trang đang hiện */
.page.active{
    opacity:1;
    transform:translateX(0) rotateY(0deg);
}

/* BUTTONS */
.btn{
    position:fixed;
    top:50%;
    transform:translateY(-50%);

    width:60px;
    height:60px;

    cursor:pointer;

    transition:0.2s;
}

.btn:hover{
    transform:translateY(-50%) scale(1.1);
}

.prev{ left:40px; }
.next{ right:40px; }
.corner-link{
    position: fixed;
    top: 20px;
    left: 20px;

    width: 80px;
    height: 80px;

    z-index: 9999;
}
.corner-button{

    position:fixed;

    top:20px;

    left:20px;

    z-index:9999;
}

.corner-button{

    position:fixed !important;

    top:0 !important;

    left:0 !important;

    z-index:99999;
}