html {
    background-color: #000000; 
}

header{
    background-color: rgb(0, 0, 0);
    color: rgb(0, 0, 0);
    text-align: center;
}

nav a{
    color: rgb(255, 255, 255);
    text-decoration: none;   
    font-size: 18px;
    margin: 20px;
    line-height: 45px;
}

nav a:hover{
    color: aquamarine;

}

#leftcol {
    color: rgb(255, 255, 255);
float: left;
width: 200px;
}
#rightcol {
    color: rgb(255, 255, 255);
margin-left: 1810px;
margin-top: 10px; 
}

.row {
    display: flex; 
    flex-direction: row;
}

.right_div {
    padding-left: 1580px;
}

main img{
    max-width: 50%;
    margin-right: auto;
    margin-left: auto;
    border-radius: 20px;
    display: flex;
    width: 210px;
}
main img:hover{
    transform:scale(1.4);
}
body{
    font-family: 'Trebuchet MS', 'Lucida Sans Unicode', 'Lucida Grande', 'Lucida Sans', Arial, sans-serif;
}
header nav a:hover{
    background: blue;
}
.footer_osn{
    background-color: #ffffff;
    color: rgb(0, 0, 0);
    padding: 20px 0;
    text-align: center;
}
.footer_content{
    max-width: 900px;
    font-size: 20px;

}
.footer_content a{
color: black;
text-decoration: none;transition: color 0.5 ease;
padding-left: 866px;
}
.footer_content a:hover{
    color: aquamarine;
}