CSS - putting my nav bar horizontaly

I am a newbie to css/html and I am trying to create a portofolio website for myself.

I would like to horizontally center my nav_bar in my page just under my image but I can't seem to make it work.

As you can see, the nav_bar is currently aligned vertically.

This is my code:

.index_navigation li {
  overflow: hidden;
  text-align: center;
  float: center;
  padding-right: 20px;
}

.index_navigation a {
  font-family: arial;
  color: black;
  text-align: center;
  padding: 14 px 16 px;
  text-decoration: none;
}

.center {
  width: 50%;
  text-align: center;
  display: block;
  background-color: transparent;
  margin-left: auto;
  border: 1px solid transparent;
  margin-right: auto;
  margin-bottom: 1px;
  float: center;
}

<div class="background_logo">
  <img src="img/logo_size.jpg" alt="Background Logo" class="center">
  <nav class="index_navigation">
    <ul>
      <li><a href="contact.html">Contact</a></li>
      <li><a href="projects.html">Projects</a></li>
      <li><a href="about.html">About</a></li>
    </ul>
  </nav>
</div>

Hopefully someone can help me :)

Thanks in advance

Solution

Use display:flex; to ul and justify-content: center; to center it

.index_navigation ul{
display:flex;
justify-content: center;
}
.index_navigation li{
overflow: hidden;
text-align: center;
float: center;
padding-right: 20px;
}

.index_navigation a {

font-family: arial;
color:black;
text-align: center;
    padding: 14px 16px;
text-decoration: none; 
}

.center{
width:50%;
text-align:center;
display:block;
background-color: transparent;
margin-left:auto;
border: 1px solid transparent;
margin-right: auto ;
margin-bottom: 1px;
float:center;
}

<!doctype html>
<html lang="en">
<head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>Xander Feliers - Portfolio</title>
    <meta name="description" content="Portfolio - Xander Feliers">
    <link rel="stylesheet" href="css/screen.css">
</head>
<body>
        <div class ="background_logo">
             <img src="https://material.angular.io/assets/img/examples/shiba1.jpg" alt="Background Logo" class ="center" >
             <nav class="index_navigation">
                 <ul>
                     <li><a href="contact.html">Contact</a></li>
                     <li><a href="projects.html">Projects</a></li>
                     <li><a href="about.html">About</a></li>
                 </ul>
             </nav>
        </div>
</body>
</html>