I have 4 images and I'm still having the same problems with lines wrapping and images not clearing

/****MAINV3.CSS***/
/*****
General
*****/

body {
    font-family: 'Hind', sans-serif;
}

#wrapper {
    max-width: 940px;
    margin: 0 auto;
    padding: 0 5%;
}

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;
}

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

h2 {
    font-size: 1.25em;
    margin: -5px 0 0;
    font-weight: normal;
}
/*****
Navigation
*****/

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

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

nav li {
    display: inline-block;
}

nav a {
    font-weight: 700;
    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 Theory
*****/

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

#gallery li {
    float: left;
    width: 28.3333%;
    margin: 2.5%;
    background-color: #f5f5f5;
    color: #bdc3c7;
}

#gallery li a p {
    margin: 0;
    padding: 5%;
    font-size: 1.0em;
    color: #bdc3c7;
}
/*****
Page Paper
*****/

.profile-photo {
    display: block;
    max-width: 300px;
    margin: 0 auto 30px;
}
/*****
Page Motion
*****/

.linksout {
    list-style: none;
    padding: 0;
    margin: 0;
    font-size: 0.9em;
}

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

.linksout li.Treehouse a {
    background-image: url('../img/treehouse.png');
}

.linksout li.MLT a {
    background-image: url('../img/mlt.jpg');
}
/*****
COLOR
*****/
/*site body*/

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

header {
    background: #75D1FF;
    border-color: #75D1FF;
}
/*mobile device nav background*/

nav {
    background: #5292B2;
}
/*logo text*/

h1,
h2 {
    color: #fff;
}

a {
    color: #009933;
}
/*nav link*/

nav a,
nav a:visited {
    color: #fff;
}
/*nav slelected link*/

nav a.selected,
nav a:hover {
    color: #BBBBBA;
}
/****RESPONSIVE.CSS***/

@media screen and (max-width: 480px) {
    /*****
Two Column Layout
*****/

    #primary {
        width: 50%;
        float: left;
    }
    #secondary {
        width: 40%;
        float: right;
    }
    /*****
Page: Portfolio/Index
*****/

    #gallery li {
        width: 45%;
    }
    #gallery li:nth-child(3n) {
        clear: left;
    }
}