<div class="wrapper">
<header>
<h1>Colve</h1> <!-- remove the </div> present here -->
<nav>
<ul class="menu1">
<li><a class="button" href="#">Home</a></li>
<li><a class="button" href="#about">About</a></li>
<li><a class="button" href="#downloads">Downloads</a>
<li><a class="button" href="invasion.html">INVASION</a></li>
</li><li><a class="button" href="contact.html">Contact</a></li>
</ul>
</nav>
In the nav css, make width to be auto
nav {
background-color:white;
float:right;
padding-right:5px;
height:60px;
display:block;
width:auto;
float:right;
}
Add width: 100%;
in header {}
because currently the header is not properly aligned.
The HTML is not well constructed. Please remove the extra and from the code.