header.css

nav {
    position: fixed;
    width: 100%;
    height: 70px;
    background-color: dimgray;
    padding-top: 5px;
    box-sizing: border-box;
    top: 0;
    left: 0;
}
nav ul li:first-child a {
    font-size: 25px;
    text-align: center;
    margin-top: -5px;
    margin-left: -15px;
  }
  
ul {
    display: flex;
}
li {
    list-style: none;
}
a {
    display: block;
    text-decoration: none;
    color: white;
    margin-right: 35px;
    text-align: center;
    font-size: 17px;
}
a:hover {
    color: rgb(163, 251, 191)
}