@import url('https://fonts.googleapis.com/css2?family=Jost:ital,wght@0,100..900;1,100..900&display=swap');
@import url('https://fonts.googleapis.com/css2?family=Open+Sans:ital,wght@0,300..800;1,300..800&display=swap');
html, body{
    height: 100vh;
    margin: 0;
    padding: 0;
}
body{
    background: #E5F7FB;
}
.content{
    position: absolute;
    width: 680px;
    left: 620px;
    height: calc(100% - 90px);
    top: 40px;
    background: #fff;
    padding: 30px;
    box-sizing: border-box;
    overflow: hidden;
    border-radius: 28px;
    box-shadow: 0 2px 3px #27528B4D, 0 6px 10px #0A25484D;
    font-family: "Open Sans", sans-serif;
}
.align-left{
    text-align: left;
}
.align-center{
    text-align: center;
}
.align-right{
    text-align: right;
}
h2{
    text-align: center;
    font-family: "Jost", serif;
    font-optical-sizing: auto;
    font-weight: 600;
    font-size: 32px;
    line-height: 110%;
}
h2 span{
    display: block;
    font-size: 20px;
}
.content_text{
    position: absolute;
    left: 30px;
    right: 30px;
    top: 30px;
    bottom: 60px;
    columns: auto 1;
    column-fill: auto;
    column-gap: 50px;
}
.main_nav{
    position: absolute;
    left: 70px;
    top: 40px;
    bottom: 103px;
    width: 325px;
}
.togglenav{
    display: block;
    width: 30px;
    height: 20px;
    background: url(img/togglenav.svg) no-repeat left top;
    background-size: auto 100%;
    margin: 40px 0 30px 0;
    cursor: pointer;
}
.main_nav ul{
    margin: 0;
    padding: 0;
    list-style: none;
}
.main_nav ul li{
    display: block;
    margin-bottom: 20px;
}
.main_nav a{
    font-family: "Jost", serif;
    font-optical-sizing: auto;
    font-weight: 600;
    font-size: 21px;
    line-height: 110%;
    color: #021A34;
    text-decoration: none;
}
.main_nav ul a span{
    display: block;
    font-size: 16px;
    line-height: 140%;
}
a.buy_book{
    display: block;
    box-sizing: border-box;
    padding: 20px 0 20px 48px;
    background: url(img/buy.svg) no-repeat left center;
    border: 2px #021A34 solid;
    border-width: 2px 0;
}
.outer_links{
    margin-top: 30px;
}
.outer_links a{
    font-size: 16px;
    display: block;
    padding-left: 48px;
}
.outer_links a:nth-child(1){
    margin-bottom: 22px;
    background: url(img/dnd.svg) no-repeat left center;
}
.outer_links a:nth-child(2){
    background: url(img/tg.svg) no-repeat 13px center;
}
.chapter>*:last-child{
    margin-bottom: 0;
    width: 100%;
    display: block;
}
.chapter *:first-child{
    margin-top: 0;
}
.chapter p, .chapter>span{
    font-size: 17px;
    line-height: 32px;
    display: block;
}
.controls{
    position: absolute;
    height: 40px;
    bottom: 0;
    left: 20px;
    right: 20px;
    text-align: center;
}
.controls .prev, .controls .next{
    position: absolute;
    top: 0;
    width: 21px;
    height: 27px;
    cursor: pointer;
    background-size: 100% auto;
    background-position: center;
    background-repeat: no-repeat;
}
.controls .prev{
    background-image: url(img/arrow_prev.svg);
    left: 0;
}
.controls .next{
    background-image: url(img/arrow_next.svg);
    right: 0;
}
.pages_counter{
    font-family: "Jost", serif;
    font-optical-sizing: auto;
    font-weight: 500;
    font-size: 18px;
    margin: 0;
}
.pages_counter .current{
    color: #1E7FFF;
}
.mob_nav{
    display: none;
}
@media(max-width:1330px) {
    .content{
        left: 400px;
    }
    .main_nav{
        width: 225px;
    }
    .main_nav a{
        font-size: 18px;
    }
    .outer_links a {
        font-size: 16px;
    }
}
@media(max-width:1100px) {
    .content{
        width: 600px;
    }
}
@media(max-width:1024px) {
    .content{
        width:100%;
        left: 0;
        height: calc(100vh - 93px);
        top: 93px;
        padding: 0 20px 120px 20px;
        border-radius: 0;
        box-shadow: none;
        background: transparent;
    }
    .main_nav{
        display: none;
    }
    .content_text{
        top: 0;
        left: 20px;
        right: 20px;
        bottom: 120px;
        columns: auto 1;
    column-fill: auto;
    column-gap: 50px;
    }
    .mob_nav{
        display: block;
        position: absolute;
        left: 0;
        right: 0;
        top: 0;
        height: 93px;
        text-align: center;
    }
    .mob_nav img{
        width: 120px;
        padding-top: 10px;
    }
    .mob_nav span.mob_togglenav{
        position: absolute;
        left: 20px;
        top: 23px;
        width: 30px;
        height: 20px;
        background: url(img/mob_togglenav.svg) no-repeat left top;
        background-size: auto 100%;
        cursor: pointer;
    }
    .mob_nav .mob_buy_book{
        position: absolute;
        right: 20px;
        top: 21px;
        width: 42px;
        height: 22px;
        line-height: 22px;
        font-size: 14px;
        padding-left: 12px;
        padding-right: 30px;
        color: #021A34;
        border: 2px #021A34 solid;
        border-radius: 17px;
        background: url(img/buy.svg) no-repeat 59px center;
        background-size: 12px auto;
    }
    .controls{
        height: 120px;
    }
    .controls .prev, .controls .next{
        width: 51px;
        height: 51px;
        filter: invert(1);
        background: none;
        background-size: 21px auto;
        top: auto;
        bottom: 30px;
    }
    .controls .prev::before, .controls .next::before{
        content: "";
        position: absolute;
        left: 0;
        right: 0;
        top: 0;
        bottom: 0;
        border-radius: 50%;
        background: #1E7FFF;
        filter: invert(1);
    }
    .controls .prev::after, .controls .next::after{
        content: "";
        position: absolute;
        left: 0;
        right: 0;
        top: 0;
        bottom: 0;
        background-repeat: no-repeat;
        background-size: 21px auto;
        background-position: center;
    }
    .controls .prev::after{
        background-image: url(img/arrow_prev.svg);
    }
    .controls .next::after{
        background-image: url(img/arrow_next.svg);
    }
    .pages_counter {
        margin: 52px 0 0 0;
    }
    .v{
        background: #fff;
    }
    .v .main_nav{
        right: 0;
        position: fixed;
        left: 0;
        top: 93px;
        padding: 20px;
        width: calc(100% - 40px);
        background: #fff;
        z-index: 9;
        height: calc(100vh - 93px);
        display: block;
        bottom: auto;
    }
    .v .main_nav img, .v .main_nav .togglenav, .v .main_nav .buy_book, .v .main_nav .outer_links{
        display: none;
    }
}
@media(min-width:1025px){
    .v .main_nav ul, .v .outer_links{
        display: none;
    }
}