* {
    box-sizing: border-box;
}
body {
    margin: 3px;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
}

header h1 {
    text-align: center;
    font-size: 40px;
    color: white;
}
header {
    padding: 40px;
    background-color: rgb(17, 124, 143);
}
nav {
    background-color: #333;
    overflow: hidden;
}
nav a {
    text-decoration: none;
    padding: 20px;
    text-align: center;
    float: left;
    color: white;
}
main {
    background-color:rgb(208, 206, 197);
    text-align: center;
    height:auto; width:auto;
    background-repeat:round;
    overflow: hidden;
}
h2 {
    padding: 20px;
}
main, section, a {
    text-align: left;
}
video {
    padding: 10px;
}

iframe {
    height: 50vh;
}

img {
    padding: 10px;
}

section h5 {
    margin: 40px;
}

footer {
    background-color: #333;
    overflow: hidden;
}

footer a {
    text-decoration: none;
    padding: 20px;
    text-align: center;
    float: left;
    color: white;
}
p a:hover{
    color:white;
    text-decoration: none;
    background-color:green;
}
ul a:hover{
    color:white;
    text-decoration: none;
    background-color:green;
}
nav a:hover{
    text-decoration: underline;
    color: tomato;
}
footer a:hover{
    text-decoration: underline;
    color: tomato;
}
nav a:visited{
    color: green;
}