CSS, HTML layout: relative div inside absolute div flows outside its container - html

Question

(Apologies in advance if this is answered elsewhere. I looked around and couldn't find anything that seemed to apply.)
I have a layout with absolute and relative positioning for divs to sit in their appropriate positions, which almost works.
http://jsfiddle.net/dex3703/TZzKN/
The #centercontainer (red) is intended to let #mainsection (orange) sit inside all the other content. I have absolute and relative positioning that I thought should work, but I have these problems:
#mainsection's bottom extends beyond #centercontainer by about 20px.
bottom, left, right, top don't have an effect. Using bottom: 20px to lift the bottom up doesn't work.
If I don't have height: 100% on #mainsection--which I sense is wrong--it and the divs inside have no height! Only a little sliver of #contentsection is visible at the top of #mainsection.
I'm only interested in this working in Chrome and IE9 as well. Hope that makes things easier.
I'm sure this is some noob problem so am grateful in advance. Thanks.

Answer 1

When you set width and height for #mainsection to be 100%, you are telling it to be the same width and height as #centercontainer, excluding padding. There are 60px on each side because the padding of #centercontainer is 60px left and right.
The reason #mainsection extends below #centercontainer is that #breadcrumbcontainer is pushing it down by 40px (the height of #breadcrumbcontainer). It only extends down 20px because there is also 20px bottom padding for #mainsection.
If you set the bottom padding of #centercontainer to the height of #breadcrumbcontainer (INCLUDING #breadcrumbcontainer's top and bottom margins), that should fix the problem. It's probably not the most elegant way to fix it. but it should work.

Answer 2

I have made some changes to your CSS. It's still no nice stylesheet, but the design is not broken anymore.
#charset "utf-8";
/*
HTML4 layout
using absolute positioning to get layout to work without HTML5/CSS flexbox
colors:
#1E242D - html frame bg
#F3F3F3 - left nav
#FFFFFF - main content, inner menu
#267EB9 - drawer bg
#DBDBDB - nav and left nav border
#4F9DD7 - selected item blue
#FFFFFF - white text
#4A4A4A - darkest text, dividers
#767676 - middle dark text
#C1C1C1 - light text
*/
html {
font-size: 62.5%;
height: 100%;
background: White;
margin: 0;
}
body
{
font-size: 1.2em;
font-family: "Segoe UI";
height: 100%;
margin: 0;
}
p
{
margin: 0;
}
/* from html5boilerplate */
nav ul, nav ol
{
list-style: none;
list-style-image: none;
margin: 0;
padding: 0;
}
#layoutdiv
{
z-index: 100;
height: 100%;
position: relative;
}
#maindiv
{
margin: 10px 60px;
position: absolute;
top: 60px;
}
header
{
position: absolute; /* change to absolute positioning */
width: 100%;
top: 0;
height: 60px;
}
header p
{
color: #FFFFFF;
}
header span
{
vertical-align: middle;
}
#logodiv
{
width: 300px;
display: inline-block;
}
#notifypanel
{
width: 40px;
position: fixed;
left: 0;
top: 110px;
bottom: 70px;
background-color: LemonChiffon;
}
#notifypanel img
{
width: 24px;
height: 24px;
}
.left
{
float: left;
}
.right
{
float: right;
}
ul
{
list-style-type:none;
list-style: none;
margin: 0;
-webkit-padding-start: 0;
-webkit-margin-before: 0;
-webkit-margin-after: 0;
}
li
{
display: inline-block; /*need inline-block or height==0! */
cursor: pointer;
vertical-align: middle;
text-align:center;
}
#topnav
{
/* position: absolute;*/
/*width: 100%;*/
/* top: 55px; with absolute positioning, move its top to the header's bottom */
display: inline-block;
vertical-align: top;
}
#topnav ul
{
/*margin-left: 15px;*/
/*height: 100%;*/
}
#topnav li
{
margin-left: 15px;
padding: 5px 10px;
font-weight: bold;
color: #767676;
height: 100%;
/*line-height: 5em; for vertical alignment */
}
#topnav li:hover
{
color: #1E242D;
background-color: #F3F3F3;
}
#topnav .selected
{
background-color: #4F9DD7;
color: White;
}
#centercontainer
{
position: absolute;
overflow:hidden;
top: 60px;
bottom: 60px;
padding: 0 60px 20px 60px;
left: 0;
right: 0;
border: 1px solid red;
}
#breadcrumbcontainer
{
top: 0;
height: 40px;
width: 100%;
margin: 0 0 10px 0;
font-family: Segoe UI Light;
font-size: 3.6em;
line-height: 0.8em;
}
#breadcrumb
{
display: inline-block;
}
#viewcontrols
{
display: inline-block;
width: 320px;
text-align: right;
}
#mainsection
{
width: 100%;
height: auto; /* mainseciton won't display unless 100%, but height is off, doesn't quite sit in containing div */
position: relative;
top:30px;
background-color: Aqua;
border: 2px solid orange;
}
#contentsection
{
position: absolute;
left: 220px;
bottom: 0;
top: 0;
padding: 5px;
box-sizing: border-box; /* makes padding, margins behave like XAML */
overflow-x: auto;
overflow-y: auto;
background-color: AliceBlue; /* remove later */
display: inline-block;
}
#leftnav
{
width: 200px;
/*position: absolute;*/
left: 0;
bottom: 0;
top: 0;
background: #F3F3F3;
overflow-y: auto;
display: inline-block;
}
#leftnav li
{
display: block;
text-align: left;
padding: 7px 0 7px 20px;
border-bottom: 1px solid #DBDBDB;
}
#leftnav img
{
display: inline-block;
vertical-align: middle;
width: 24px;
height: 22px;
}
#leftnav p
{
display: inline-block;
vertical-align: middle;
margin: 0 0 0 10px;
}
#leftnav .selected
{
background-color: #4F9DD7;
}
#leftnav .selected:hover
{
background-color: #4387B7;
}
#leftnav li:hover
{
background-color: #FdFdFd;
}
footer
{
background: #267EB9;
height: 60px;
position: absolute;
bottom: 0;
width: 100%;
line-height: 1em; /* vertically centers header content .. see http://phrogz.net/CSS/vertical-align/index.html */
text-align: center; /* centers the center button div */
}
footer img
{
margin-right: 15px;
height: 24px;
width: 24px;
}
footer p
{
display: inline-block;
margin: 0;
vertical-align: super;
color: #FFFFFF;
font-size: 0.8em;
}
.footerleft
{
margin-left: 20px;
position: relative;
top: 17px;
}
.footerright
{
margin-right: 10px;
position: relative;
top: 17px;
}
.footercenter
{
display: inline-block;
position: relative;
top: 13px;
}
.footercenter div
{
display: inline-block;
margin-right: 20px;
}
.footercenter p
{
display: block;
}
.footercenter img
{
margin: 0;
}