menu.html

 <span style = "font-family: Helvetica, Arial, sans-serif";> <!-- span means only apply this formatting to things inside the tags -->
<style>

/*ul stands for unordered list, this is a way to specify the style of it*/
ul {
    list-style-type: none;
    margin: 0;
    padding: 0;
    height: 55px
    overflow: hidden; /*hides any text that overflows, maybe not necessary*/
    background-color: black; /*color of menu*/
    position: fixed; /*keep menu at the top of the page when you scroll*/
    top: 0; /*put the menu at the top of the page*/
    width: 100%; /*make it span the whole width of the page*/
}

/*li is list item, we want the links to be leftmost*/

li {
    float: left;
}

/*a is hyperlink*/
li a {
    display: block;
    color: white; /*Color of text*/
    padding: 16px; /*Space between links*/
    text-decoration: none;
}
</style>

<ul>
  <li><a href="/BasicSite/index.html">Home</a></li>
  <li><a href="/BasicSite/tab1.html">Tab 1</a></li>
  <li><a href="https://www.facebook.com/groups/1006815496091821">Tab 2</a></li>
  <li><a href="/BasicSite/tab3.html">Tab 3</a></li>
  <li><a href="/BasicSite/subfolder/tab4.html">Tab 4</a></li>
</ul>
</span>