Navigation gets messed up when applying float: right to media queries

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

   /************************************
    PAGE: 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 #006dcc;
  }

}

/************************************
header
***********************************/
#header {
  float:left;
  margin: 0 0 30px 0;
  padding: 5px 0 0 0;
  width: 100%;
   color: #FFFFFF;
}

#logo {
  max-width: 940px;
  text-align: center;
  margin: 0;
}

header {
  background: #6abaff;
  padding: 40px 0 0;
}

header a {
   color: white;
}

/* site body */

#wrapper {
  max-width: 940px;
  margin: 0 auto;
  padding: 5% 5%;
}
body {
  font-family: 'Merriweather', serif; font-weight: 400;
 background-color: #FFFFFF;
}

/* font styling */

a, p a:visited {
  color: #4dacff;
}

a:hover {
  color: #fff;
}

a, a:visited {
 text-decoration: none;
}

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

h2 {
  font-family: 'Merriweather', serif; font-weight: 400; font-style:italic ;
  font-size: 1em;
  margin: -5px 0 0;
}

h3, h4, p {
  font-family: 'Merriweather', serif; font-weight: 400;
}

h3 {
  margin: 0 0 1em 0;
}

/************************************
NAVIGATION
***********************************/
nav {
  text-align:center;
  padding: 10px 0;
  margin: 50px 0 0;
  background-color: #4dacff;
}

nav a:hover {
  color: #006dcc;
}
nav a.whaat {
  font-weight: bold;
  color: #006dcc;
}

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

nav li {
  display: inline-block;

}

nav a {
  padding: 15px 10px;
   color: white;
}

/************************************
FOOTER
***********************************/
footer {
  font-size: 0.75em;
  text-align:center;
  clear: both;
  padding-top: 50px;
  padding-bottom: 50px;
}

.social-icon {
  width: 20px;
  height: 20px;
  margin: 0 5px;
}

/************************************
gallery
***********************************/

img {
  max-width: 100%;
}

#gallery {
  margin: 0;
  padding: 0;
  list-style: none;
}

#gallery li a p {
  margin: 0;
  padding: 5%;
  font-size: 0.75em;
  color: #bdc3c7; 
}

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

/************************************
`PAGE: ABOUT
***********************************/

.profile-photo {
  display: block;
  max-width: 80%;
  max-height: 80%;
  margin: 0 auto 30px;
  border-radius: 80%;
}

/************************************
`PAGE: CONTACT
***********************************/

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