Need help centering my cta

Question

Ok, so i cant seem to center my call to action, any ideas why its stuck to the left? keep in mind that im using bootstrap and sass

    <div class="jumbotron">
      <nav>
        <div class="row">
          <div class="col-md-12">
            <ul>
              <li class="p_nav">Home</li>
              <li class="p_nav">About</li>
              <li class="p_nav">Work</li>
              <li class="p_nav">Contact</li>
            </ul>
          </div>
        </div>
      </nav>
      <div class="container">
        <h1>Name</h1>
        <p class="p_jumbo">secondary text</p>
        <div class="cta">Learn more</div>
      </div>
    </div>

and the css. Do i need a parrent with a position tag maybe?

.jumbotron {
  height: 100vh;
  background-image: url("/img/jumbobg.png");
  background-size: cover; }

nav ul {
  list-style: none; }
  nav ul li {
    display: inline;
    float: right;
    margin: 20px;
    padding: 0px;
    margin-top: 0px; }

.cta {
  border: 1px solid #FFFFFF;
  border-radius: 100px;
  font-family: Avenir-Light;
  font-size: 20.25px;
  color: #FFFFFF;
  display: inline-block;
  padding: 10px 20px;
  text-align: center;
  margin: 0 auto; }

Answer 1

The margin: 0 auto isn't working because of inline-block display. remove this line and give your cta a width.

.cta {
    border: 1px solid #FFFFFF;
    border-radius: 100px;
    font-family: Avenir-Light;
    font-size: 20.25px;
    color: #FFFFFF;
    /* display: inline-block; */
    padding: 10px 20px;
    text-align: center;
    margin: 0 auto;
    width: 200px;
}