:root{
    --main-color:#02B3E4;
    --second-color:#EFEFEF;
    --third-color:#666666;
}

*{
    border-radius: 2px;
    padding: 0;
    margin: 0;
}
 

body {
    font-family: "Open Sans", sans-serif;
}


header{
    padding: 10px 100px;
    width: 800px;
    margin: auto;
}

@media  (max-width:900px) {
    header{
        padding: 10px 50px;
        width: auto;
    }
}

header .back a{
    color: var(--main-color);
    text-decoration: none;
}

header .title{
    margin: 10px 0;
}

header .author{
    display: flex;
    align-items: center;

}

header img{
    height: 50px;
    border-radius: 50%;
}

header .info{
    margin-left: 10px;
}

header .author .name{
    color: var(--main-color);
}

body>.container{
    margin: auto;
    padding: 0 100px;
    width: 800px;
}

@media  (max-width:900px) {
    body>.container{
        padding: 10px 50px;
        width: auto;
    }
}

main p{    
    margin: 10px 0;
}


main .above-img{
    position: relative;
}

main .above-img::before{
    position: absolute;
    margin: 0 -13px;
    background-color: #000;
    content: "";
    height: 100%;
    width: 5px;
}

article img{
    width: 1000px;
    height: 250px;
    margin-left: -100px;

}

@media  (max-width:900px) {
    article img{
        width: 100%;
        height: 100%;
        margin-left: 0;
    
    }}

article div{
    margin: 10px 0;
}

article .content p{
    margin: 10px 0;
}

article  h3{
    font-size: 26px;
    margin: 20px 0;
}

article .content pre{
    position: relative;
    padding: 30px 20px;
    background-color: #F4F5F6;
    white-space: pre-wrap;
    word-wrap: break-word;
    text-align: justify;
}

article .content pre::before{
    position: absolute;
    margin: -30px -25px;
    background-color: var(--main-color);
    content: "";
    height: 100%;
    width: 5px;
}

main ul,
main ol{
    padding: 20px;
}

footer{
    background-color: var(--third-color);
    color: var(--second-color);
    padding: 10px 0 40px 10px;
    font-size: 25px;
}

footer .share{
    display: flex;

    flex-direction: column;
    align-items: center;
}

footer .icons{
    margin-top: 10px;
    display: grid;
    grid-auto-flow: column;
    grid-gap: 30px;
}

footer a{
    color: var(--second-color);
}