(HTML) Problem with making a extra sidebar and content bar help needed.

[Quizer9O8]

Hi there, I'm trying to build my very own website with Notepad++ but i stumbled across a problem.
I was trying to make a extra Sidebar and Content bar but when i do this it will mess up the original or it won't even come.
Can someone explain to me what i do wrong, here is the code I've been trying to make work: default.css

/*********************************************************************************/
/* Sidebar                                                                       */
/*********************************************************************************/
 
    #sidebar
    {
        background:  #363636;
        float: left;
        width: 345px;
    }
 
    #sidebar .title h2
    {
        font-size: 1.6em;
    }
 
    #sidebar .box1
    {
        margin-bottom: 3em;
    }
 
 
 
 
 
 
 
 
 
 
 
 
 
 
/*********************************************************************************/
/* Sidebar2                                                                       */
/*********************************************************************************/
 
    #sidebar2
    {
        background:  #363636;
        float: right;
        width: 345px;
    }
 
    #sidebar .title h2
    {
        font-size: 1.6em;
    }
 
    #sidebar2 .box1
    {
        margin-bottom: 3em;
    }
 
------------------------------------------------------------
 
index.html
 
<div id="sidebar"> <div class="box2"> <div class="title"> <h2>Text</h2> </div> <ul class="style0"> </ul> </div> </div> </div> </div> <div id="sidebar2"> <div class="box2"> <div class="title"> <h2>Text</h2> </div> <ul class="style0"> </ul> </div> </div> </div> </div>
------------------------------------------------------------

Thank you for reading

[Quizer9O8]

And where do I have to place it?