Keep div certain distance from another div - html

Question

I have a login box DIV and below that another login button DIV which is 1% margin top from the Login Box DIV.
The login box div has these styles:
.login-box {
height: 39%;
width: 100%;
}
.login-box-wrap {
width: 30%;
height: 98%;
margin: 0 auto;
border: 1px solid #3f3f3f;
background-color: #609ac4;
border-radius: 5px 5px 5px 5px;
margin-top: 1%;
min-width: 250px;
max-width: 500px;
max-height: 350px;
min-height: 100px;
}
.logintextbox {
background-color: transparent;
border: none;
border-bottom-color: rgba(176, 221, 245, 1);
border-bottom-style: solid;
border-bottom-width: 2px;
width: 98%;
height: 32%;
font-size: 1.2em;
font-family: open sans;
color: white;
padding-left: 2%;
}
Then when i shrink it alittle more then button overlaps the box like this:
This is the login button styles:
.login-button {
height: 5%;
width: 100%;
margin-top: 1%;
position: fixed;
}
.login-button-wrap {
width: 30%;
height: 100%;
margin: 0 auto;
min-width: 250px;
max-width: 500px;
min-height: 20px;
max-height: 31px;
}
#btnLogin {
height: 100%;
width: 100%;
background: linear-gradient(#73afda,#609ac4);
border: 1px solid #3f3f3f;
border-radius: 5px 5px 5px 5px;
font-family: Arial;
color: white;
font-size: 15px;
}
How can i keep the button around 10px/1% margin top from the box at all resolutions
**EDIT: **
Here is the HTML
<div class="login-box">
<div class="login-box-wrap">
<input id="txt_client_reference" type="text" class="logintextbox" placeholder="Client Reference" />
<input id="txt_postcode" type="text" class="logintextbox" placeholder="Postcode" />
<input id="txt_date_of_birth" type="text" class="logintextbox" placeholder="Date of Birth" />
</div>
</div>
<div class="login-button">
<div class="login-button-wrap">
<asp:Button ID="btnLogin" runat="server" Text="Log in" CssClass="loginButton" OnClientClick="checkForm(); valid_postcode()" />
</div>
</div>

Answer 1

I might be a little far off on this one, but you have position fixed there, which doesn't really care about your margin anymore.