line 3 divs on one line - html

Question

I am trying to get a mailchimp signup form to be on the same line instead of the default 3 lines.
I have tried to add display: inline-block; which made no difference and I have also tried to put a container around the divs but that didn't make a difference.
I do not have much experience of css but I do understand it. I was wondering if someone with a little more experience may be able to help.
<!-- Begin MailChimp Signup Form -->
<div id="mc_embed_signup">
<form action="//digital-realms.us12.list-manage.com/subscribe/post?u=b3dcff09f16684d5f73852c78&id=af1750ad39" method="post" id="mc-embedded-subscribe-form" name="mc-embedded-subscribe-form" class="validate" target="_blank" novalidate>
<div id="mc_embed_signup_scroll">
<div>Sign up to free e-Mail alerts for the latest news, offers & more: </div>
<div class="mc-field-group">
<input type="email" value="" name="EMAIL" class="required email" id="mce-EMAIL">
</div>
<div id="mce-responses" class="clear">
<div class="response" id="mce-error-response" style="display:none"></div>
<div class="response" id="mce-success-response" style="display:none"></div>
</div> <!-- real people should not fill this in and expect good things - do not remove this or risk form bot signups-->
<div style="position: absolute; left: -5000px;"><input type="text" name="b_b3dcff09f16684d5f73852c78_af1750ad39" tabindex="-1" value=""></div>
<div class="clear opt-in" "><input type="submit" value="Sign Up" name="subscribe" id="mc-embedded-subscribe" class="button"></div>
</div>
</form>
</div>
<!--End mc_embed_signup-->
Thank you.
ps: The code came from MailChimp and they set the classes so I do not have any css of my own to include.

Answer 1

Use the following html
.parent {
width: 100%;
}
.block1 {
width: 30%;
float: left;
padding-right: 10px;
}
.block2 {
width: 30%;
float: left;
padding-right: 10px;
}
.block3 {
width: 30%;
float: left;
}
<div class="parent">
<div class="block1">Content 1</div>
<div class="block2">Content 2</div>
<div class="block3">Content 3</div>
</div>
You may change the width. and insert your html into the content 1, content 2, content 3