.by {
    text-align: center;
    font-size: 120%;
    padding-top: 2em
    }
.author {
    text-align: center;
    font-size: 135%
    }
.transl {
    text-align: center;
    font-size: 120%;
    padding-top: 2em
    }
.series {
    text-align: center;
    font-size: 120%;
    padding-top: 5em
    }
.co {
    text-align: center;
    font-size: 120%;
    padding-top: 5em
    }
.year {
    text-align: center;
    font-size: 130%;
    padding-bottom: 3em
    }
body {
    margin-left: 10%;
    margin-right: 10%
    }
h1, h2 {
    text-align: center;
    clear: both
    }
p {
    margin-top: 0.51em;
    text-align: left;
    margin-bottom: 0.49em
    }
hr {
    width: 33%;
    margin-top: 2em;
    margin-bottom: 2em;
    margin-left: auto;
    margin-right: auto;
    clear: both
    }
hr.chap {
    width: 65%
    }