My navigation bar disappears and my navigation anchors are on a white background once I do the responsive code.

@media screen and (min-width: 660px) {

  /***header***/

  nav {
    background: none;
    float: right;
    font-size: 1.125em;
    margin-right: 5%;
    text-align: right;
    width: 45%;
  }

  #logo {
    float: left;
    margin-left: 5%;
    text-align: left;
    width: 45%;
  }
  h1 {
    font-size: 2.5em;
  }
  h2 {
    font-size: 0.825em;
    margin-bottom: 20px;
  }
  header {
    border-bottom: 5px solid #599a68;
    margin-bottom: 60px;
  }
}


@media screen and (min-width: 480px) {

  /***two coloumn layout***/
  #primary {
  width: 50%;
  float: left;
  }

  #secondary {
  width: 40%;
  float: right;
  }

  /*** contact page ****/

  #gallery li {
    width: 28.3333%

  }
  #gallery li:nth-child(4n) {
    clear: left;
  }

/***About page***/
  .profile-photo {
    float: left;
    margin: 0 5% 80px 0;
  }

}

/********
General
*********/
body {
  font-family:'Ubuntu', sans-serif;
}

#wrapper {
  max-width: 940px;
  margin: 0 auto;
  padding: 0 3%; 
}
a {
  text-decoration: none;
}

img {
  max-width: 100%;
}
h3 {
  margin: 0 0 1em 0;
}

/***heading***/

header {
  float: left;
  margin: 0 0 30px 0;
  padding: 5px 0 0 0;
  width: 100%;
}

#logo{
  text-align: center;
  margin: 0;
  padding: 0 1%;
}

h1{
  font-family:'Dosis', sans-serif;
  margin: 15px 0;
  font-size: 1.75em;
  font-weight: normal;
  line-height: 0.8em;
}
h2{
  font-size: 0.75em;
  margin: -5px 0 0;
  font-weight: normal;
}

/***Navigation***/

nav {
  text-align: center;
  padding: 10px 0;
  margin: 20px 0 0;
}

nav ul {
  list-style: none;
  margin: 0 10px;
  padding: 0;
}

nav li {
  display: inline-block;
}

nav a {
  font-weight: 800;
  padding: 15px 10px;
}

/****footer****/
footer{
  font-size: 0.75em;
  text-align: center;
  clear: both;
  padding-top: 50px;
  color: #ccc;
}
.social-icon {
  width: 20px;
  height: 20px;
  margin: 0 5px;
}

/*********** Page portfolio *******/
#gallery {
  margin: 0;
  padding: 0;
  list-style: none;
}

#gallery li {
  float: left;
  width: 45%;
  margin: 2.5%;
  background-color: #f5f5f5;
  color: #bdc3c7;
}

#gallery li a p {
  margin: 0;
  padding: 5%;
  font-size: 0.5em;
  color: #bdc3c7
}

/***page about***/

.profile-photo {
  display: block;
  max-width: 150px;
  margin: 0 auto 30px;
  border-radius:100%;
}

/***contact page***/
.contact-info {
  list-style: none;
  padding 0;
  margin: 0;
  font-size: 0.9em;
}

.contact-info a {
  display: block;
  min-height: 20px;
  background-repeat:no-repeat;
  background-size: 20px 20px;
  padding: 0 0 0 30px;
  margin: 0 0 10px;
}

.contact-info li.phone a {
  background-image: url('../img/phone.png');
}

.contact-info li.mail a {
  background-image: url('../img/mail.png');
}


/*site body*/
body{
  background-color:#fff;
  color:#999;
}


/*green header*/
header{
  background:#5ab17b;
  border-color:#599a68;
}

/**nav background on mobile devices**/
nav {
  background: #599a68;
}

/*logo text*/
h1, h2 {
  color:#fff;
}

a {
  color:#6ab47b;
}
/*nav link*/
nav a, nav a:visited {
  color:#fff;
}
/*selected nav link*/
nav a.selected, nav a:hover {
  color:#32673f;
}