body, h1, h2, p, ul, li {
    margin: 0;
    padding: 0;
}

body {
    font-family: Arial, sans-serif;
    background-color: #f0f0f0;
}

header {
    background-color:  #008080;
    color: #fff;
    text-align: center;
    padding: 20px;
}

nav {
    background-color: #808080;
    color: #fff;
}

nav ul {
    list-style: none;
    display: flex;
    justify-content: center;
    padding: 10px;
}

nav a {
    text-decoration: none;
    color: #fff;
    margin: 0 20px;
}

main {
    padding: 20px;
}

footer {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background-color: #008080;
    color: #fff;
    text-align: center;
    padding: 10px;
}

.submeny nav{
    flex-direction: column;
    display: inline-block;
    background-color: #fff;
    overflow: auto;

}

.submeny  a{
    background-color:#0a0a23;
    color: #fff;
    border:none; 
    border-radius:10px; 
    padding:15px;
    min-height:30px; 
    margin: 10px;
    font-family: Arial, sans-serif ;
    text-decoration: none;
    padding: 1rem;
    background-color: #008080;
    color: #fff;
    border:1px solid white;
    display: inline-block;
}