Нужно позиционировать блоки горизонтально. Описание классов в точности дублирует описание классов библиотеки Bootstrap. Не могу найти ошибку.
<div class="wrapper">
<div class="wrapper-inner">
<div class="av-col-4">Lorem ipsum dolor sit amet, consectetur adipisicing elit. Maiores, porro velit quibusdam explicabo rem laboriosam error aliquam commodi necessitatibus numquam quae deleniti odit debitis. Sapiente, placeat mollitia assumenda perspiciatis voluptas.</div>
<div class="av-col-4">Lorem ipsum dolor sit amet, consectetur adipisicing elit. Maiores, porro velit quibusdam explicabo rem laboriosam error aliquam commodi necessitatibus numquam quae deleniti odit debitis. Sapiente, placeat mollitia assumenda perspiciatis voluptas.</div>
<div class="av-col-4">Lorem ipsum dolor sit amet, consectetur adipisicing elit. Maiores, porro velit quibusdam explicabo rem laboriosam error aliquam commodi necessitatibus numquam quae deleniti odit debitis. Sapiente, placeat mollitia assumenda perspiciatis voluptas.</div>
</div>
</div>
.wrapper{
background-color: #56f;
margin-left: auto;
margin-right: auto;
padding-right: 15px;
padding-left: 15px;
max-width: 100%;
}
.wrapper-inner {
background-color: #3f3f4f;
margin-right: -15px;
margin-left: -15px;
}
.av-col-4 {
background-color: green;
position: relative;
min-height: 1px;
padding-left: 15px;
padding-right: 15px;
float: left;
width: 33.33333333%;
}
.wrapper:after,
.wrapper:before,
.wrapper-inner:after,
.wrapper-inner:before {
display: table;
content: ' ';
}
.wrapper:after,
.wrapper-inner:after {
clear: both;
}
Ссылка на Editey workspace