<div class="col-6">
<div class="d7">
<form>
<input type="text" placeholder="Поиск">
<button type="submit"></button>
</form>
</div>
</div>
.d7 input {
width: 639px;
height: 50px;
padding-left: 15px;
border-radius: 42px;
background: #F5F5F5;
outline: none;
position: relative;
}
.d7 button {
width: 639px;
height: 50px;
background: none;
border: none;
position: absolute;
top: -2px;
right: 1;
}
.d7 button:before{
content: "\f002";
font-family: FontAwesome;
color: #324b4e;
}