html { 
    background-color: white; 
}
body { 
    max-width: 520px;
    margin: auto; 
    background-color: lightgray; 
    padding: 15px 15px;
    /* max-height: 300px; */
}
#content{
    max-width: 500px;
    margin: auto;
    background-color: lightgray;
    padding: 10px;
    border: 1px solid black;
    font-size: 12px;
    height: 510px;
}

h1{
    text-align: center;
} 
p{
    text-align: center;
    color: blue;
    font-size: 14px;
}
img{
    display: block;
    margin: 0 auto;
    width: 50%;
}
#topics{
    margin: 20px auto;
    width: 50%;
    font-size: 12px;
}
h2{
    text-align: center;
}