*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
body {
    font-family: Arial, sans-serif;
    background-color: #f0f0f0;
    margin: 0;
    padding: 40px;
}


header {
    background-color: #0b7a66; 
    padding: 10px 15px;
}


nav ul {
    list-style-type: none;
    margin: 0;
    padding: 0;
    display: flex;
    align-items: center;
    border-right:3px solid #ffffff;
}


nav li {
    color: #ffffff;
    font-size: 18px;
}


nav a {
    color: #ffffff; 
    text-decoration: none;
    padding: 0 8px;
}

nav a:hover {
    color: #0000ff; 
}

a:active {
    color: #ff0000; 
}
main{
    width: 90%;
    height: 500px;
    border: 10px solid gray;
    padding: 20px 35px;
}

.back-link {
    display: inline-block;
    padding: 10px 16px;
    border-radius: 5px;
    background: linear-gradient(115deg, #9bb8c8 0%, #dce8ed 52%, #86a8ba 100%);
    color: #19364b;
    font-weight: bold;
    text-decoration: none;
}

.back-link:hover,
.back-link:focus-visible {
    background: linear-gradient(115deg, #88a8bb 0%, #cedfe7 52%, #789db2 100%);
}

body{
    font-size: 14px;
}