Question

I want the btn next to the string. I can’t figure it out even using CSS inline

 <span class="subscribe_button"> <h3>Books</h3> <%= render 'follow_form' %></span>

CSS:

.subscribe_button {
display: inline;
}

Answer 1

You have some invalid HTML here.

A block level element cannot be within an inline one, this is basic HTML knowledge.

What I suggest you do is wrap both elements in a div and use float: left;

<div class="wrap">

<h3>Books</h3>
<span class="subscribe_button"> unsubscribe</span>

</div>

CSS:

.wrap
{
    width: 300px;
}

.wrap h3, 
.wrap span
{
    float: left;
}

.wrap span
{
    margin-left: 10px/*your value*/;
}

I also suggest you go read up on HTML rules, what is allowed where and why they are or are not allowed.

http://jsfiddle.net/Kyle_Sevenoaks/zJUZs/