You have to wrap the two inputs into divs :
<form method="post">
<div class="input--email">
<input name="email" type="text" class="email">
</div>
<div class="input--search">
<input name="send" type="submit" class="search">
</div>
</form>
And give them the same shadows :
.input--email, .input--search {
float: left;
box-shadow: 0 0 40px 6px rgba(0,0,0,0.65);
height: 45px;
}
.input--email{
width: 395px;
}
.input--search{
margin-left: 15px;
width: 60px;
}
.email, .search {
width: 100%;
height: 100%;
position: relative;
-webkit-appearance: none;
}
.search {
cursor: pointer;
}
Here is a fiddle : http://jsfiddle.net/VLy6Q/