CSS Layout Techniques

There are several basic techniques to use in your CSS to create multi-column layouts. What follows is are demonstrations of the barebones techniques needed.

You should consult these while working on your final projects.

Two Column Layouts

Two column layouts on the web are very common for basic sites. Generally, they consist of a header, footer and then two columns in the content area. One column is for the main content while the other is a sidebar.

The essential CSS code for a centered 2 column layout with the CSS on the left is as follows.

.container {
  margin: 0 auto;    /* This centers the page in modern browsers */
  width: 90%;        /* This sets our total page width */
}

header {
  width: 100%;       /* This sets the header to stretch the full page width */
}

nav li {
  display: inline;   /* Make our navigation display in a line */
}

.main-content {
  float: right;      /* This causes the content to move to the right */
  width: 60%;        /* We need to set the width whenever we float an element */
}

aside {
  float: left;       /* This causes the sidebar to move to the left */
  width: 40%;        /* We need to set the width whenever we float an element */
}

footer {
  clear: both;       /* This makes sure that the footer clears both the sidebar and content floats */
  width: 100%;       /* This sets the footer to stretch the full page width */
}

Here are the key points to consider for this layout:

2 Column Demos

Two column layout with sidebar on the left

Two column layout with sidebar on the right

The only difference here is in the floats in the CSS. We tell the content to float to left and the sidebar to the right.


Three Column Layout

A three column layout generally consists of a main content area in the middle and a sidebar on both the right and left sides.

Below is the basic CSS code for a 3 column layout.

.container {
  margin: 0 auto;    /* This centers the page in modern browsers */
  width: 90%;        /* This sets our total page width */
}

header {
  width: 100%;       /* This sets the header to stretch the full page width */
}

nav li {
  display: inline;   /* Make our navigation display in a line */
}

.main-content {
  float: left;       /* This causes the content to move to the left */
  width: 60%;        /* We need to set the width whenever we float an element */
}

.aside-left {
  float: left;       /* This causes the sidebar to move to the left
                          It's going to appear to the left of the content because 
                          we declared it first in our HTML page */
  width: 20%;        /* We need to set the width whenever we float an element */
}

.aside-right {
  float: right;      /* This causes the sidebar to move to the right */
  width: 20%;        /* We need to set the width whenever we float an element */
}

footer {
  clear: both;        /* This makes sure that the footer clears both the sidebar and content floats */
  width: 100%;        /* This sets the footer to stretch the full page width */
}

3 Column Demo

Three column layout with sidebar on the right and left


Three Column Unbalanced Layout

The standard three column layout can be easily modified to have the sidebars both on one side to create and unbalanced feel.

Below is the basic CSS code for a 3 column unbalanced layout.

.container {
  margin: 0 auto;    /* This centers the page in modern browsers */
  width: 90%;        /* This sets our total page width */
}

header {
  width: 100%;       /* This sets the header to stretch the full page width */
}

nav li {
  display: inline;   /* Make our navigation display in a line */
}

.main-content {
  float: left;       /* This causes the content to move to the left 
                          It's going to appear to the left of the content because 
                          we declared it first in our HTML page */
  width: 60%;        /* We need to set the width whenever we float an element */
}

aside-one {
  float: left;       /* This causes the sidebar to move to the left */
  width: 20%;        /* We need to set the width whenever we float an element */
}

aside-two {
  float: left;       /* This causes the sidebar to move to the left */
  width: 20%;        /* We need to set the width whenever we float an element */
}

footer {
  clear: both;        /* This makes sure that the footer clears both the sidebar and content floats */
  width: 100%;        /* This sets the footer to stretch the full page width */
}

3 Column Demo

Three column layout with sidebar on the right and left


Two Column Stretch Layout

For lack of a better term, I'm calling this type of layout a "stretch" layout. Basically this type of layout is still centered and has a certain width, but the backgrounds of each section stretch to the edge of the page.

Below is the basic CSS code for a 2 column stretch layout.

.centerLayout {      /* We use a class for this since we're using it in several places */
  margin: 0 auto;    /* This centers the page in modern browsers */
  width: 90%;        /* This sets our total page width */
}

nav li {
  float: left;       /* Floating also makes our navigation display in a line */
}

.main-content {
  float: left;       /* This causes the content to move to the left */
  width: 60%;        /* We need to set the width whenever we float an element */
}

aside {
  float: left;       /* This causes the sidebar to move to the left */
  width: 40%;        /* We need to set the width whenever we float an element */
}

footer {
  clear: both;       /* This makes sure that the footer clears both the sidebar and content floats */
}

Here are the key points to consider for this layout:

2 Column Stretch Demo