style.css

body,header{
    margin: 0;
    padding: 0;
    /*background-color: beige;*/
    background-color: #F9F5F0;
}

h1,h2,h3,h4,h5{
    margin-left: 10px;
}

header{

    width: 100%;
    height: 40px;
    background-color: #70ACB1;
}

span a{
    display: inline-block;
    height: 40px;
    width:120px;
    text-align: center;
    float: right;
    color:white;
    font-size: 20px;
    line-height: 40px;
}

span a:hover{
    /*color: #C6F1E7;*/
    color:white;
    /*background-color: #C6F1E7;*/
    opacity: 0.6;
}

span a:visited,link{
    color:white;
}

a{
    font-family: 微软雅黑,"Helvetica Neue", Helvetica, Arial, sans-serif;
    text-decoration: none;
    font-weight: 500;
}

a:visited{
    color:black;
}

a:link{
    color:black;
}


/*********************/
@media screen and (min-width: 1000px){
    #container{
        display: flex;
        flex-wrap: wrap;
        justify-content: space-around;
        align-items: flex-start;
        align-self: stretch;
    }
}