Understanding divs - html

Question

I'm struggling to understand divs.
I want to have the 'nav' panel expand vertically as required. The second issue I have is that I can't seem to get padding to work. Any changes I make tend to end up with the 'section' div drop below the 'nav' div.
Please see below jsfiddle and code.
Thanks in advance.
https://jsfiddle.net/s59cwy9s/
<div id="container">
<div id="nav">
test
</div>
<div id="section">
test
<br><br><br><br>
test
<br><br><br><br>
test
</div>
</div>
#container
{
width: 1156px;
margin-top: 0;
margin-left: auto;
margin-right: auto;
box-shadow: 5px 5px 10px rgb(0,0,0);
position: relative;
background-color: transparent;
height: auto;
}
#header
{
background-color:black;
color:white;
text-align: center;
padding:5px;
}
#nav
{
line-height:30px;
background-color:#eeeeee;
min-height: 100px;
min-width: 80px;
float:left;
padding: 15px;
display: inline-block;
height: auto;
}
#section
{
/*float: none;*/
padding: 10px;
display: block;
/*position: absolute;*/
/*overflow: auto;*/
background-color: white;
width: auto;
height: auto;
}

Answer 1

This may be due to the fact that your name bar doesn't span the height of the webpage completely. Try something like height :100% for the navbar. It might do the trick.

Answer 2

Here is some help :
https://jsfiddle.net/6ubhyL5k/
Some advices :
Take time to really understand how the page flow works (float : left/right) so you will then understand how padding and margin work when you have floating div
Use what you really know and don't improvise :)
Don't use br to make spaces between blocks (margin and padding are what you should use)
Take a look at how bootstrap works and never forget the responsive design

Answer 3

First I will recommend is using box-sizing attribute
It contains any type of padding or borders within the container's width and height. Find more about it Here. So i suggest:
*
{
box-sizing:border-box;
/* Use browser prefixes if u want support for other browsers */
}
Second is add a class to the container which contains elements wit float css attribute like clearfix and add this code:
.clearfix:after {
visibility: hidden;
display: block;
font-size: 0;
content: " ";
clear: both;
height: 0;
}
or you can just create a div after the container containing elements with float css attribute and clear it.
<div class='clear'></div>
.class
{
clear:both;
}
Using float as much as it is useful brings about a problem in layout if not properly used. https://css-tricks.com/all-about-floats/
My Solution:
html,body {height:auto; width:100%; background:red; }
* { box-sizing:border-box; margin:0; padding:0; display:block; position:relative; }
#container
{
min-width:800px;
height:auto;
margin:0 auto;
width:100%;
}
#nav
{
float:left;
width:30%;
padding: 15px;
line-height:30px;
background-color:#eeeeee;
min-height: 100px;
min-width: 80px;
background:white;
}
#section
{
float:left;
width:70%;
padding:0 100px;
background:yellow;
}
.clearfix:after
{
visibility: hidden;
display: block;
font-size: 0;
content: " ";
clear: both;
height: 0;
}
Hope It Helps You. Though i recommend researching more on layouts since there's other layout which will give you less problem than floats.

Answer 4

Try
#section{
clear:both;
}
JSfiddle
clear:both allows floated divs to stop continuing on the same line with the other floated ones, and drop below.
Update: https://jsfiddle.net/s59cwy9s/2/
You could fix your issue by giving a margin-right to the #nav