I am following along with this exercise, but nothing changes in my page as it does in the video?

/* ================================= 
  Base Element Styles
==================================== */

* {
    box-sizing: border-box;
}

body {
    font-family: 'Varela Round', sans-serif;
    line-height: 1.6;
    color: #3a3a3a;
}

p {
    font-size: .95em;
    margin-bottom: 1.8em;
}

h2,
h3,
a {
    color: #093a58;
}

h2,
h3 {
    margin-top: 0;
}

a {
    text-decoration: none;
}

img {
    max-width: 100%;
}

/* ================================= 
  Base Layout Styles
==================================== */

/* ---- Navigation ---- */

.name {
    font-size: 1.25em;
  margin: 0;
}

.main-nav {
margin-top: 5px;
}

.name a,
.main-nav a {
    text-align: center;
  display: block;
  padding: 10px 15px;
}

.main-header {
padding-top: .5em;
padding-bottom: .5em;
}

.banner,
.main-footer {
 text-align: center; 
}

.main-nav a {
    font-size: .95em;
    color: #3acec2;
    text-transform: uppercase;
}

.main-nav a:hover {
    color: #093a58;
}

/* ---- Layout Containers ---- */

.banner {
    color: #fff;
    background: #3acec2;
  padding: 3.2em 0;
  margin-bottom: 60px;
  }

.col {
padding-right: 1em;
padding-left: 1em;
}

.main-footer {
    background: #d9e4ea;
    padding: 2em 0;
    margin-top: 30px;
}

/* ---- Page Elements ---- */

.logo {
    width: 190px;
}

.headline {
 margin-bottom: 0;
}

/* ================================= 
  Media Queries
==================================== */

@media (min-width: 769px) {

  .container {
width: 90%;
margin: 0 auto;  
}

.name,
.col {
    float: left;
  }

.primary,
.secondary {
  width: 50%;
}


.main-nav {
    float: right;
  }

  .main-nav li {
    display: inline-block;
    margin-left: 15px;
  }

.tagline {
  font-size: 1.4em;
}

    /* ---- Float clearfix ---- */

    .clearfix::after {
        content: " ";
        display: table;
        clear: both;
    }
}

@media (min-width: 1025px) {

  .container {
    width: 80%;
    max-width: 1150px;
  }

.primary {
width: 40%;
}

.secondary,
.teriary {
  width: 30%;
}

}