Harvard Extension School
CSCI E-12 Fundamentals of Web Site Development | Spring 2019

# Session 06 - CSS and Image

Harvard Extension School
Spring 2019

Course Web Site: http://cscie12.dce.harvard.edu/

Instructor email: david_heitmeyer@harvard.edu
Course staff email: cscie12@dce.harvard.edu

### Topics

1. Display and Visibility
2. CSS and Lists for Navigation
3. Lists as Side Navigation
4. Dropdown Menus
5. Breadcrumb Navigation
6. CSS Rounded Borders
7. CSS Shadows
8. CSS Gradients
9. Graphics and Images
10. JPEG
11. GIF
12. PNG
13. SVG
14. Comparison of Image Formats
15. Working with Images

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- img
- img
- img
- img
- img

## Display and Visibility

Can use CSS to change display. This is useful not only to change the 'default' way things are displayed, but also to manipulate display properties using JavaScript.

Two main properties that control display:

- `display` - commonly used
- `visibility` - less commonly used

## The "display" property

Common values:

- block
- inline
- none
- inline-block

### display: inline

Key points:

- remove list styling
- change from "block" to "inline" display

`ul { list-style: none; }`
`li { display: inline; }`

### display: none

Example 6.1 - display: none; - Example 6.1 (Without Styles) | <ul><li>American League <ul><li id="ale">East <ul><li>Baltimore</li><li>Boston</li><li>New York</li><li>Toronto</li><li>Tampa Bay</li></ul></li><li id="alc">Central <ul><li>Chicago</li><li>Cleveland</li><li>Detroit</li><li>Kansas City</li><li>Minnesota</li></ul></li><li id="alw">West <ul><li>Los Angeles</li><li>Oakland</li><li>Texas</li><li>Seattle</li></ul></li></ul></li></ul> #ale { display: none; } #alw { display: none; } * { font-family: arial,helvetica,sans-serif; }

- Markup
- Style
- Screenshot

     <ul>
    <li>American League<ul>
    <li id="ale">East<ul>
    <li>Baltimore</li>
    <li>Boston</li>
    <li>New York</li>
    <li>Toronto</li>
    <li>Tampa Bay</li>
    </ul></li>
    <li id="alc">Central<ul>
    <li>Chicago</li>
    <li>Cleveland</li>
    <li>Detroit</li>
    <li>Kansas City</li>
    <li>Minnesota</li>
    </ul></li>
    <li id="alw">West<ul>
    <li>Los Angeles</li>
    <li>Oakland</li>
    <li>Texas</li>
    <li>Seattle</li>
    </ul></li>
    </ul></li>
    </ul>

In `style` element (`<style type="text/css">`) within `head` element:

    #ale { display: none; }
    #alw { display: none; }
    * { font-family: arial,helvetica,sans-serif; }

Full list for the American League:

## Visibility

Visibility controls whether or not an element is displayed. The element still takes up space in the block model.

Example 6.2 - visibility: hidden; - Example 6.2 (Without Styles) | <ul><li>American League <ul><li id="ale">East <ul><li>Baltimore</li><li>Boston</li><li>New York</li><li>Toronto</li><li>Tampa Bay</li></ul></li><li id="alc">Central <ul><li>Chicago</li><li>Cleveland</li><li>Detroit</li><li>Kansas City</li><li>Minnesota</li></ul></li><li id="alw">West <ul><li>Los Angeles</li><li>Oakland</li><li>Texas</li><li>Seattle</li></ul></li></ul></li></ul> #ale { visibility: hidden; } #alw { visibility: hidden; } * { font-family: arial,helvetica,sans-serif; }

- Markup
- Style
- Screenshot

     <ul>
    <li>American League<ul>
    <li id="ale">East<ul>
    <li>Baltimore</li>
    <li>Boston</li>
    <li>New York</li>
    <li>Toronto</li>
    <li>Tampa Bay</li>
    </ul></li>
    <li id="alc">Central<ul>
    <li>Chicago</li>
    <li>Cleveland</li>
    <li>Detroit</li>
    <li>Kansas City</li>
    <li>Minnesota</li>
    </ul></li>
    <li id="alw">West<ul>
    <li>Los Angeles</li>
    <li>Oakland</li>
    <li>Texas</li>
    <li>Seattle</li>
    </ul></li>
    </ul></li>
    </ul>

In `style` element (`<style type="text/css">`) within `head` element:

    #ale { visibility: hidden; }
    #alw { visibility: hidden; }
    * { font-family: arial,helvetica,sans-serif; }

Full list for the American League:

## display: inline-block

Remember how we saw we can float things?
`display: inline-block` gives us another way to achieve similar results -- but with `inline-block`, the contents are not taken out of the calculation of the parent container!

Compare the two JSFiddle examples of `li`:

- inline-block for li
- float for li

## CSS and Lists for Navigation

Harvard Homepage - lists are outlined in magenta and list items in green. Note that some lists are "horizontal" and some are "vertical" -- exactly how a list is rendered can be controlled by CSS

Top:

Footer:

## Lists and Navigation

Harvard Extension School

## Inline and Inline-block Lists

Key points:

- remove list styling
- change from "block" to "inline" or "inline-block" display

    ul { list-style: none; }
    li { display: inline; }

or

    ul { list-style: none; }
    li { display: inline-block; }

### list-style: none

Example 6.3 - list-style: none; - Example 6.3 (Without Styles) | <ul id="extglobalnav"><li>About</li><li>Calendar</li><li>Courses</li><li>Contact Us</li><li>Faculty Directory</li><li>Login</li></ul>ul#extglobalnav { list-style: none; }

- Markup
- Style
- Screenshot

    <ul id="extglobalnav">
    <li>About</li>
    <li>Calendar</li>
    <li>Courses</li>
    <li>Contact Us</li>
    <li>Faculty Directory</li>
    <li>Login</li>
    </ul>

In `style` element (`<style type="text/css">`) within `head` element:

    ul#extglobalnav {
      list-style: none;
    }

### li {display: inline;}

Example 6.4 - list-style: none; - Example 6.4 (Without Styles) | <ul id="extglobalnav"><li>About</li><li>Calendar</li><li>Courses</li><li>Contact Us</li><li>Faculty Directory</li><li>Login</li></ul>ul#extglobalnav { list-style: none; padding-left: 0; } ul#extglobalnav li { display: inline; padding-left: 2em; }

- Markup
- Style
- Screenshot

    <ul id="extglobalnav">
    <li>About</li>
    <li>Calendar</li>
    <li>Courses</li>
    <li>Contact Us</li>
    <li>Faculty Directory</li>
    <li>Login</li>
    </ul>

In `style` element (`<style type="text/css">`) within `head` element:

    ul#extglobalnav {
      list-style: none;
      padding-left: 0;
    }
    ul#extglobalnav li {
      display: inline;
      padding-left: 2em;
    }

### li {display: inline-block;}

Example 6.5 - list-style: none; - Example 6.5 (Without Styles) | <ul id="extglobalnav"><li>About</li><li>Calendar</li><li>Courses</li><li>Contact Us</li><li>Faculty Directory</li><li>Login</li></ul>ul#extglobalnav { list-style: none; padding-left: 0; } ul#extglobalnav li { display: inline-block; width: 8em; border: thin solid black; margin-right: 3px; text-align: center }

- Markup
- Style
- Screenshot

    <ul id="extglobalnav">
    <li>About</li>
    <li>Calendar</li>
    <li>Courses</li>
    <li>Contact Us</li>
    <li>Faculty Directory</li>
    <li>Login</li>
    </ul>

In `style` element (`<style type="text/css">`) within `head` element:

    ul#extglobalnav {
      list-style: none;
      padding-left: 0;
    }
    ul#extglobalnav li {
      display: inline-block;
      width: 8em;
      border: thin solid black;
      margin-right: 3px;
      text-align: center
    }

## Advantage of inline-block?

Best of both "inline" and "block" worlds!

- JS Fiddle of inline-block list-item navigation

## Lists as Horizontal Navigation

Key points:

- remove list styling
- change from "block" to "inline-block" (or "inline") display

Example 6.6 - simple list - Example 6.6 | <ul><li>Academics</li><li>Tuition and Enrollment</li><li>Resources and Policies</li><li>Inside Extension</li></ul>

- Markup
- Display

    <ul>
    <li>Academics</li>
    <li>Tuition and Enrollment</li>
    <li>Resources and Policies</li>
    <li>Inside Extension</li>
    </ul>

- Academics
- Tuition and Enrollment
- Resources and Policies
- Inside Extension

Example 6.7 - inline list items - Example 6.7 (Without Styles) | <ul id="extnav"><li>Academics</li><li>Tuition and Enrollment</li><li>Resources and Policies</li><li>Inside Extension</li></ul>ul#extnav { list-style: none; } ul#extnav li { display: inline-block; }

- Markup
- Style
- Screenshot

    <ul id="extnav">
    <li>Academics</li>
    <li>Tuition and Enrollment</li>
    <li>Resources and Policies</li>
    <li>Inside Extension</li>
    </ul>

In `style` element (`<style type="text/css">`) within `head` element:

    ul#extnav {
      list-style: none;
    }
    ul#extnav li {
      display: inline-block;
    }

Note the labeling of the current area of the site the user is in with the "active" class.

Example 6.8 - Inline List Items - Example 6.8 (Without Styles) | <ul id="extnav"><li><a href="#">Academics</a></li><li class="active"><a href="#">Tuition and Enrollment</a></li><li><a href="#">Resources and Policies</a></li><li><a href="#">Inside Extension</a></li></ul>* { background-color: white; } ul#extnav { list-style: none; font-weight: bold; font-family: Arial, Verdana, Helvetica, sans-serif; color: #1e1e1e; background-color: white; margin-top: 1em; } ul#extnav li { display: inline-block; margin: 0; padding: 0; } ul#extnav a { padding: 0.5em; margin-right: 0; background-color: white; border-right: 1px solid black; } ul#extnav li:last-child a { border-style: none; } ul#extnav a:link, ul#extnav a:visited { color: black; text-decoration: none; } ul#extnav a:hover { color: #a51c30; text-decoration: underline; } ul#extnav .active { background-color: #f5f5f8;} ul#extnav .active a:link, ul#extnav .active a:visited, ul#extnav .active a:hover, ul#extnav .active a:active { background-color: #f5f5f8; color: #a51c30; text-decoration: none; }

- Markup
- Style
- Screenshot

    <ul id="extnav">
    <li><a href="#">Academics</a></li>
    <li class="active"><a href="#">Tuition and Enrollment</a></li>
    <li><a href="#">Resources and Policies</a></li>
    <li><a href="#">Inside Extension</a></li>
    </ul>

In `head` element:

    <link rel="stylesheet" type="text/css" href="example8.css"/>

In example8.css

    * {
      background-color: white;
    }

    ul#extnav {
      list-style: none;
      font-weight: bold;
      font-family: Arial, Verdana, Helvetica, sans-serif;
      color: #1e1e1e;
      background-color: white;
      margin-top: 1em;
    }

    ul#extnav li {
      display: inline-block;
      margin: 0;
      padding: 0;
    }

    ul#extnav a {
      padding: 0.5em;
      margin-right: 0;
      background-color: white;
      border-right: 1px solid black;
    }
    ul#extnav li:last-child a {
      border-style: none;
    }
    ul#extnav a:link,
    ul#extnav a:visited {
      color: black;
      text-decoration: none;
    }

    ul#extnav a:hover {
      color: #a51c30;
      text-decoration: underline;
    }
    ul#extnav .active {  background-color: #f5f5f8;}
    ul#extnav .active a:link,
    ul#extnav .active a:visited,
    ul#extnav .active a:hover,
    ul#extnav .active a:active {
      background-color: #f5f5f8;
      color: #a51c30;
      text-decoration: none;
    }

## Lists as Side Navigation

Key points:

- remove list styling
- make "a" element "block" display

Default styling:

Note: "a" display property is set to "block". This makes the hyperlink active over the whole area, not just with the text.

Example 6.9 - lists as navigation - Example 6.9 (Without Styles) | <div id="navigation1"><ul><li><a href="http://www.baylor.edu/">Baylor</a></li><li><a href="http://www.iastate.edu/">Iowa State</a></li><li><a href="http://www.ku.edu/">Kansas</a></li><li><a href="http://www.ksu.edu/">Kansas State</a></li><li><a href="http://www.ou.edu/">Oklahoma</a></li><li><a href="http://www.okstate.edu/">Oklahoma State</a></li><li><a href="http://www.tcu.edu/">Texas Christian</a></li><li><a href="http://www.utexas.edu/">Texas</a></li><li><a href="http://www.ttu.edu/">Texas Tech</a></li><li><a href="http://www.wvu.edu/">West Virginia</a></li></ul></div>#navigation1 { font-family: Arial, Verdana, Helvetica, sans-serif; font-weight: bold; font-size: 0.7em; width: 15em; border-right: 1px solid #333; margin-bottom: 1em; background-color: #ddd; color: #900; } #navigation1 ul { list-style: none; margin: 0; padding: 0; } #navigation1 ul li { margin: 0; border-top: 1px solid #333; } #navigation1 ul li a { display: block; background-color: #ddd; border-top: 1px solid #333; border-left: 5px solid #333; text-decoration: none; padding: 5px 2px 5px 0.5em; } #navigation1 ul li a:link, #navigation1 ul li a:visited { color: #900; } #navigation1 ul li a:hover { color: #fff; background-color: #900;}

- Markup
- Style
- Screenshot

    <div id="navigation1"><ul>
    <li><a href="http://www.baylor.edu/">Baylor</a></li>
    <li><a href="http://www.iastate.edu/">Iowa State</a></li>
    <li><a href="http://www.ku.edu/">Kansas</a></li>
    <li><a href="http://www.ksu.edu/">Kansas State</a></li>
    <li><a href="http://www.ou.edu/">Oklahoma</a></li>
    <li><a href="http://www.okstate.edu/">Oklahoma State</a></li>
    <li><a href="http://www.tcu.edu/">Texas Christian</a></li>
    <li><a href="http://www.utexas.edu/">Texas</a></li>
    <li><a href="http://www.ttu.edu/">Texas Tech</a></li>
    <li><a href="http://www.wvu.edu/">West Virginia</a></li>
    </ul></div>

In `head` element:

    <link rel="stylesheet" type="text/css" href="example9.css"/>

In example9.css

    #navigation1 {
      font-family: Arial, Verdana, Helvetica, sans-serif;
      font-weight: bold;
      font-size: 0.7em;
      width: 15em;
      border-right: 1px solid #333;
      margin-bottom: 1em;
      background-color: #ddd;
      color: #900;
    }
    #navigation1 ul {
      list-style: none;
      margin: 0;
      padding: 0;
    }
    #navigation1 ul li {
      margin: 0;
      border-top: 1px solid #333;
    }
    #navigation1 ul li a {
      display: block;
      background-color: #ddd;
      border-top: 1px solid #333;
      border-left: 5px solid #333;
      text-decoration: none;
      padding: 5px 2px 5px 0.5em;
    }
    #navigation1 ul li a:link,
    #navigation1 ul li a:visited
    { color: #900; }
    #navigation1 ul li a:hover {
         color: #fff;
         background-color: #900;}

## Lists as Navigation

Nested list styled as "clamshell" navigation.

- remove list styling
- make "a" element "block" display

- styles for secondary nested lists (e.g. selector for `ul ul a`)
Example 6.10 - Nested lists for 'clamshell' navigation - Example 6.10 (Without Styles) | <div id="navclam"><ul><li><a href="http://big12sports.collegesports.com/">Big XII</a><ul><li><a href="http://www.baylor.edu/">Baylor</a></li><li><a href="http://www.iastate.edu/">Iowa State</a></li><li><a href="http://www.ku.edu/">Kansas</a></li><li><a href="http://www.ksu.edu/">Kansas State</a></li><li><a href="http://www.ou.edu/">Oklahoma</a></li><li><a href="http://www.okstate.edu/">Oklahoma State</a></li><li><a href="http://www.tcu.edu/">Texas Christian</a></li><li><a href="http://www.utexas.edu/">Texas</a></li><li><a href="http://www.ttu.edu/">Texas Tech</a></li><li><a href="http://www.wvu.edu/">West Virginia</a></li></ul></li><li><a href="http://www.ivyleaguesports.com/">Ivy League</a><ul class="collapse"><li><a href="http://www.brown.edu/">Brown</a></li><li><a href="http://www.columbia.edu/">Columbia</a></li><li><a href="http://www.cornell.edu/">Cornell</a></li><li><a href="http://www.dartmouth.edu/">Dartmouth</a></li><li><a href="http://www.harvard.edu/">Harvard</a></li><li><a href="http://www.upenn.edu/">Penn</a></li><li><a href="http://www.princeton.edu/">Princeton</a></li><li><a href="http://www.yale.edu/">Yale</a></li></ul></li><li><a href="http://www.pac-12.com/">Pac 12</a><ul class="collapse"><li><a href="http://www.arizona.edu/">Arizona</a></li><li><a href="http://www.asu.edu/">Arizona State</a></li><li><a href="http://www.berkeley.edu/">California</a></li><li><a href="http://www.cu.edu/">Colorado</a></li><li><a href="http://www.uoregon.edu/">Oregon</a></li><li><a href="http://www.oregonstate.edu/">Oregon State</a></li><li><a href="http://www.stanford.edu/">Stanford</a></li><li><a href="http://www.ucla.edu/">UCLA</a></li><li><a href="http://www.usc.edu/">USC</a></li><li><a href="http://www.utah.edu/">Utah</a></li><li><a href="http://www.washington.edu/">Washington</a></li><li><a href="http://www.wsu.edu/">Washington State</a></li></ul></li></ul></div>#navclam { font-family: Arial, Verdana, Helvetica, sans-serif; font-weight: bold; font-size: 1.2em; width: 10em; border-right: 1px solid #333; margin-bottom: 1em; background-color: #ddd; color: #900; } #navclam ul { list-style: none; margin: 0; padding: 0; } #navclam ul li { margin: 0; border-top: 1px none #333; } #navclam ul li a { display: block; background-color: #ccc; border-top: 1px none #333; border-right: 1px solid #333; border-bottom: thin dotted #333; border-left: 5px solid #333; text-decoration: none; padding: 5px 2px 5px 0.5em; } #navclam a:link { color: #900; } #navclam a:visited { color: #900; } #navclam a:hover { color: #fff; background-color: #900; border-top: 1px outset #333; border-right: 1px outset #333; border-bottom: 1px outset #333; border-left: 5px outset #333; } #navclam a:active { color: #fff; background-color: #900; border-top: 1px inset #333; border-right: 1px inset #333; border-bottom: 1px inset #333; border-left: 5px inset #333; } #navclam ul ul a { list-style: none; padding-left: 1.5em; font-size: 90%; font-weight: normal; } #navclam ul.collapse { display: none; }

- Markup
- Style
- Screenshot

    <div id="navclam"><ul>
    <li><a href="http://big12sports.collegesports.com/">Big XII</a><ul>
    <li><a href="http://www.baylor.edu/">Baylor</a></li>
    <li><a href="http://www.iastate.edu/">Iowa State</a></li>
    <li><a href="http://www.ku.edu/">Kansas</a></li>
    <li><a href="http://www.ksu.edu/">Kansas State</a></li>
    <li><a href="http://www.ou.edu/">Oklahoma</a></li>
    <li><a href="http://www.okstate.edu/">Oklahoma State</a></li>
    <li><a href="http://www.tcu.edu/">Texas Christian</a></li>
    <li><a href="http://www.utexas.edu/">Texas</a></li>
    <li><a href="http://www.ttu.edu/">Texas Tech</a></li>
    <li><a href="http://www.wvu.edu/">West Virginia</a></li>
    </ul></li>
    <li><a href="http://www.ivyleaguesports.com/">Ivy League</a><ul class="collapse">
    <li><a href="http://www.brown.edu/">Brown</a></li>
    <li><a href="http://www.columbia.edu/">Columbia</a></li>
    <li><a href="http://www.cornell.edu/">Cornell</a></li>
    <li><a href="http://www.dartmouth.edu/">Dartmouth</a></li>
    <li><a href="http://www.harvard.edu/">Harvard</a></li>
    <li><a href="http://www.upenn.edu/">Penn</a></li>
    <li><a href="http://www.princeton.edu/">Princeton</a></li>
    <li><a href="http://www.yale.edu/">Yale</a></li>
    </ul></li>
    <li><a href="http://www.pac-12.com/">Pac 12</a><ul class="collapse">
    <li><a href="http://www.arizona.edu/">Arizona</a></li>
    <li><a href="http://www.asu.edu/">Arizona State</a></li>
    <li><a href="http://www.berkeley.edu/">California</a></li>
    <li><a href="http://www.cu.edu/">Colorado</a></li>
    <li><a href="http://www.uoregon.edu/">Oregon</a></li>
    <li><a href="http://www.oregonstate.edu/">Oregon State</a></li>
    <li><a href="http://www.stanford.edu/">Stanford</a></li>
    <li><a href="http://www.ucla.edu/">UCLA</a></li>
    <li><a href="http://www.usc.edu/">USC</a></li>
    <li><a href="http://www.utah.edu/">Utah</a></li>
    <li><a href="http://www.washington.edu/">Washington</a></li>
    <li><a href="http://www.wsu.edu/">Washington State</a></li>
    </ul></li>
    </ul></div>

In `head` element:

    <link rel="stylesheet" type="text/css" href="example10.css"/>

In example10.css

    #navclam {
      font-family: Arial, Verdana, Helvetica, sans-serif;
      font-weight: bold;
      font-size: 1.2em;
      width: 10em;
      border-right: 1px solid #333;
      margin-bottom: 1em;
      background-color: #ddd;
      color: #900;
    }
    #navclam ul {
      list-style: none;
      margin: 0;
      padding: 0;
    }
    #navclam ul li {
      margin: 0;
      border-top: 1px none #333;
    }
    #navclam ul li a {
      display: block;
      background-color: #ccc;
      border-top: 1px none #333;
      border-right: 1px solid #333;
      border-bottom: thin dotted #333;
      border-left: 5px solid #333;
      text-decoration: none;
      padding: 5px 2px 5px 0.5em;
    }
    #navclam a:link {
      color: #900;
    }
    #navclam a:visited {
      color: #900;
    }
    #navclam a:hover {
      color: #fff;
      background-color: #900;
      border-top: 1px outset #333;
      border-right: 1px outset #333;
      border-bottom: 1px outset #333;
      border-left: 5px outset #333;
    }
    #navclam a:active {
      color: #fff;
      background-color: #900;
      border-top: 1px inset #333;
      border-right: 1px inset #333;
      border-bottom: 1px inset #333;
      border-left: 5px inset #333;
    }
    #navclam ul ul a {
      list-style: none;
      padding-left: 1.5em;
      font-size: 90%;
      font-weight: normal;
    }
    #navclam ul.collapse {
      display: none;
    }

Default styling of nested list:

## Dropdown Menus

Key points:

- Make the list 'horizontal'
- Hide the secondary lists
- Use the CSS ":hover" pseudo-class to change secondary list display property

Example 6.11 - drop down menu - Example 6.11 (Without Styles) | <ul id="dropdown1"><li><a href="#">AL East</a><ul><li><a href="#">Baltimore</a></li><li><a href="#">Boston</a></li><li><a href="#">New York</a></li><li><a href="#">Toronto</a></li><li><a href="#">Tampa Bay</a></li></ul></li><li><a href="#">AL Central</a><ul><li><a href="#">Chicago</a></li><li><a href="#">Cleveland</a></li><li><a href="#">Detroit</a></li><li><a href="#">Kansas City</a></li><li><a href="#">Minnesota</a></li></ul></li><li><a href="#">AL West</a><ul><li><a href="#">Los Angeles</a></li><li><a href="#">Oakland</a></li><li><a href="#">Texas</a></li><li><a href="#">Seattle</a></li></ul></li></ul>ul { padding: 0; margin: 0; list-style: none; } li { float: left; position: relative; width: 10em; } li ul { display: none; top: 1em; left: 0; } li:hover ul { display: block; }

- Markup
- Style

     <ul id="dropdown1">
    <li><a href="#">AL East</a><ul>
    <li><a href="#">Baltimore</a></li>
    <li><a href="#">Boston</a></li>
    <li><a href="#">New York</a></li>
    <li><a href="#">Toronto</a></li>
    <li><a href="#">Tampa Bay</a></li>
    </ul></li>
    <li><a href="#">AL Central</a><ul>
    <li><a href="#">Chicago</a></li>
    <li><a href="#">Cleveland</a></li>
    <li><a href="#">Detroit</a></li>
    <li><a href="#">Kansas City</a></li>
    <li><a href="#">Minnesota</a></li>
    </ul></li>
    <li><a href="#">AL West</a><ul>
    <li><a href="#">Los Angeles</a></li>
    <li><a href="#">Oakland</a></li>
    <li><a href="#">Texas</a></li>
    <li><a href="#">Seattle</a></li>
    </ul></li>
    </ul>

In `style` element (`<style type="text/css">`) within `head` element:

    ul {
      padding: 0;
      margin: 0;
      list-style: none;
      }
    li {
      float: left;
      position: relative;
      width: 10em;
      }
    li ul {
      display: none;
      top: 1em;
      left: 0;
      }
    li:hover ul { display: block; }

## Dropdown Menus

Example 6.12 - drop-down menu - Example 6.12 (Without Styles) | <ul id="dropdown2"><li><a href="#">AL East</a><ul><li><a href="#">Baltimore</a></li><li><a href="#">Boston</a></li><li><a href="#">New York</a></li><li><a href="#">Toronto</a></li><li><a href="#">Tampa Bay</a></li></ul></li><li><a href="#">AL Central</a><ul><li><a href="#">Chicago</a></li><li><a href="#">Cleveland</a></li><li><a href="#">Detroit</a></li><li><a href="#">Kansas City</a></li><li><a href="#">Minnesota</a></li></ul></li><li><a href="#">AL West</a><ul><li><a href="#">Los Angeles</a></li><li><a href="#">Oakland</a></li><li><a href="#">Texas</a></li><li><a href="#">Seattle</a></li></ul></li></ul>ul { padding: 0; margin: 0; list-style: none; } li { float: left; position: relative; width: 10em; } li ul { display: none; top: 1.7em; left: 0; } li > ul { top: auto; left: auto; } li:hover ul { display: block; } #dropdown2 li { border: thin solid navy; font-family: calibri,verdana,tahoma,helvetica,sans-serif; background-color: #ccf; } #dropdown2 ul li { background-color: #eef; } #dropdown2 a {display:block; padding: 0.25em;} #dropdown2 a:link, #dropdown2 a:visited, #dropdown2 a:hover, #dropdown2 a:active { text-decoration: none; font-weight: bold; } #dropdown2 a:hover { background-color: navy; color: #ccf; }

- Markup
- Style
- Screenshot

     <ul id="dropdown2">
    <li><a href="#">AL East</a><ul>
    <li><a href="#">Baltimore</a></li>
    <li><a href="#">Boston</a></li>
    <li><a href="#">New York</a></li>
    <li><a href="#">Toronto</a></li>
    <li><a href="#">Tampa Bay</a></li>
    </ul></li>
    <li><a href="#">AL Central</a><ul>
    <li><a href="#">Chicago</a></li>
    <li><a href="#">Cleveland</a></li>
    <li><a href="#">Detroit</a></li>
    <li><a href="#">Kansas City</a></li>
    <li><a href="#">Minnesota</a></li>
    </ul></li>
    <li><a href="#">AL West</a><ul>
    <li><a href="#">Los Angeles</a></li>
    <li><a href="#">Oakland</a></li>
    <li><a href="#">Texas</a></li>
    <li><a href="#">Seattle</a></li>
    </ul></li>
    </ul>

In `style` element (`<style type="text/css">`) within `head` element:

    ul {
      padding: 0;
      margin: 0;
      list-style: none;
      }
    li {
      float: left;
      position: relative;
      width: 10em;
      }
    li ul {
      display: none;
      top: 1.7em;
      left: 0;
    }
    li > ul {
      top: auto;
      left: auto;
    }
    li:hover ul { display: block; }
    #dropdown2  li {
      border: thin solid navy;
      font-family: calibri,verdana,tahoma,helvetica,sans-serif;
      background-color: #ccf;
      }
    #dropdown2 ul li { background-color: #eef; }
    #dropdown2 a {display:block; padding: 0.25em;}
    #dropdown2 a:link,
    #dropdown2 a:visited,
    #dropdown2 a:hover,
    #dropdown2 a:active
      { text-decoration: none; font-weight: bold; }
    #dropdown2 a:hover { background-color: navy; color: #ccf; }

## Dropdown Menus: Vertical

Example 6.13 - drop-down/out menu - Example 6.13 (Without Styles) | <ul id="dropdown3"><li><a href="#">AL East</a><ul><li><a href="#">Baltimore</a></li><li><a href="#">Boston</a></li><li><a href="#">New York</a></li><li><a href="#">Toronto</a></li><li><a href="#">Tampa Bay</a></li></ul></li><li><a href="#">AL Central</a><ul><li><a href="#">Chicago</a></li><li><a href="#">Cleveland</a></li><li><a href="#">Detroit</a></li><li><a href="#">Kansas City</a></li><li><a href="#">Minnesota</a></li></ul></li><li><a href="#">AL West</a><ul><li><a href="#">Los Angeles</a></li><li><a href="#">Oakland</a></li><li><a href="#">Texas</a></li><li><a href="#">Seattle</a></li></ul></li></ul>ul { padding: 0; margin: 0; list-style: none; } li { position: relative; width: 10em; } li ul { display: none; position: absolute; top: 1.7em; left: 0; } li > ul { top: auto; left: auto; } li:hover ul { display: block; } #dropdown3 li ul { margin-left: 10em; margin-top: -1.8em; } #dropdown3 li { border: thin solid navy; font-family: calibri,verdana,tahoma,helvetica,sans-serif; background-color: #ccf; } #dropdown3 ul li { background-color: #eef; } #dropdown3 a {display:block; padding: 0.25em;} #dropdown3 a:link, #dropdown3 a:visited, #dropdown3 a:hover, #dropdown3 a:active { text-decoration: none; font-weight: bold; } #dropdown3 a:hover { background-color: navy; color: #ccf; }

- Markup
- Style

     <ul id="dropdown3">
    <li><a href="#">AL East</a><ul>
    <li><a href="#">Baltimore</a></li>
    <li><a href="#">Boston</a></li>
    <li><a href="#">New York</a></li>
    <li><a href="#">Toronto</a></li>
    <li><a href="#">Tampa Bay</a></li>
    </ul></li>
    <li><a href="#">AL Central</a><ul>
    <li><a href="#">Chicago</a></li>
    <li><a href="#">Cleveland</a></li>
    <li><a href="#">Detroit</a></li>
    <li><a href="#">Kansas City</a></li>
    <li><a href="#">Minnesota</a></li>
    </ul></li>
    <li><a href="#">AL West</a><ul>
    <li><a href="#">Los Angeles</a></li>
    <li><a href="#">Oakland</a></li>
    <li><a href="#">Texas</a></li>
    <li><a href="#">Seattle</a></li>
    </ul></li>
    </ul>

In `style` element (`<style type="text/css">`) within `head` element:

    ul {
      padding: 0;
      margin: 0;
      list-style: none;
      }
    li {
      position: relative;
      width: 10em;
    }
    li ul {
      display: none;
      position: absolute;
      top: 1.7em;
      left: 0;
    }
    li > ul {
      top: auto;
      left: auto;
    }
    li:hover ul { display: block; }

    #dropdown3 li ul {
      margin-left: 10em;
      margin-top: -1.8em;
    }
    #dropdown3  li {
      border: thin solid navy;
      font-family: calibri,verdana,tahoma,helvetica,sans-serif;
      background-color: #ccf;
      }
    #dropdown3 ul li { background-color: #eef; }
    #dropdown3 a {display:block; padding: 0.25em;}
    #dropdown3 a:link,
    #dropdown3 a:visited,
    #dropdown3 a:hover,
    #dropdown3 a:active
      { text-decoration: none; font-weight: bold; }
    #dropdown3 a:hover { background-color: navy; color: #ccf; }

## Breadcrumb Navigation

> "Just wait, Gretel, until the moon rises, and then we shall see the crumbs of bread which I have strewn about, they will show us our way home again.", Hansel in Hansel and Gretel

Key points:

- inline display
- background image for arrows

Markup "breadcrumb" navigation using nested lists so that markup reflects the parent/child or hierarchy relationship.

Strategy is similar to that of creating tabs. Use "display: inline" to make list items inline; use background image for "li" to show arrow.

Example 6.14 - Nested lists for 'breadcrumb' navigation - Example 6.14 (Without Styles) | <div id="breadcrumb"><ul><li><a href="http://dmoz.org/">Top</a><ul><li><a href="http://dmoz.org/Science/">Science</a><ul><li><a href="http://dmoz.org/Science/Biology/">Biology</a><ul><li><a href="http://dmoz.org/Science/Biology/Genetics/"> Genetics</a><ul><li><a href="http://dmoz.org/Science/Biology/Genetics/Genomics/"> Genomics</a><ul><li><span>Pharmacogenetics</span></li></ul></li></ul></li></ul></li></ul></li></ul></li></ul></div>/* Order of pseudo-"a" elements: LoVe HAte (Link, Visited, Hover, Active */ #breadcrumb a:link , #breadcrumb a:visited , #breadcrumb a:hover , #breadcrumb a:active , #breadcrumb li span { color: navy; font-family: Tahoma, Arial, Helvetica, sans-serif; font-size: small; font-weight: normal; padding: 0.5em; text-decoration: none; } #breadcrumb a:hover { text-decoration: underline; } #breadcrumb li span { color: black; } #breadcrumb { background-color: #ddd; } #breadcrumb ul { display: inline; margin-left: 0; padding-left: 0; } #breadcrumb ul li { display: inline; } #breadcrumb ul ul li { background-image: url(images/arrow.gif); background-position: left; background-repeat: no-repeat; padding-left: 25px; }

- Markup
- Style

    <div id="breadcrumb"><ul>
    <li><a href="http://dmoz.org/">Top</a><ul>
    <li><a href="http://dmoz.org/Science/">Science</a><ul>
    <li><a href="http://dmoz.org/Science/Biology/">Biology</a><ul>
    <li><a href="http://dmoz.org/Science/Biology/Genetics/">Genetics</a><ul>
    <li><a href="http://dmoz.org/Science/Biology/Genetics/Genomics/">Genomics</a><ul>
    <li><span>Pharmacogenetics</span></li>
    </ul></li>
    </ul></li>
    </ul></li>
    </ul></li>
    </ul></li>
    </ul></div>

In `head` element:

    <link rel="stylesheet" type="text/css" href="example14.css"/>

In example14.css

    /*
      Order of pseudo-"a" elements:
      LoVe HAte (Link, Visited, Hover, Active
    */
    #breadcrumb a:link , #breadcrumb a:visited ,
    #breadcrumb a:hover , #breadcrumb a:active , #breadcrumb li span {
      color: navy;
      font-family: Tahoma, Arial, Helvetica, sans-serif;
      font-size: small;
      font-weight: normal;
      padding: 0.5em;
      text-decoration: none;
    }
    #breadcrumb a:hover {
      text-decoration: underline;
    }
    #breadcrumb li span {
      color: black;
    }
    #breadcrumb {
      background-color: #ddd;
    }
    #breadcrumb ul {
      display: inline;
      margin-left: 0;
      padding-left: 0;
    }
    #breadcrumb ul li {
      display: inline;
    }
    #breadcrumb ul ul li {
      background-image: url(images/arrow.gif);
      background-position: left;
      background-repeat: no-repeat;
      padding-left: 25px;
    }

## Breadcrumbs with a flat list

Strategy is similar to that of creating tabs. Use "display: inline" to make list items inline; use background image for "li" to show arrow.

Example 6.15 - Nested lists for 'breadcrumb' navigation - Example 6.15 (Without Styles) | <div id="breadcrumbf"><ul><li><a href="http://dmoz.org/">Top</a></li><li><a href="http://dmoz.org/Science/">Science</a></li><li><a href="http://dmoz.org/Science/Biology/">Biology</a></li><li><a href="http://dmoz.org/Science/Biology/Genetics/">Genetics</a></li><li><a href="http://dmoz.org/Science/Biology/Genetics/Genomics/">Genomics</a></li><li><span>Pharmacogenetics</span></li></ul></div>/* Order of pseudo-"a" elements: LoVe HAte (Link, Visited, Hover, Active */ #breadcrumbf a:link, #breadcrumbf a:visited, #breadcrumbf a:hover, #breadcrumbf a:active, #breadcrumbf li span { color: navy; font-family: Tahoma, Arial, Helvetica, sans-serif; font-size: small; font-weight: normal; padding: 0.5em; text-decoration: none; } #breadcrumbf a:hover { text-decoration: underline; } #breadcrumbf li span { color: black; } #breadcrumbf ul { background-color: #ddd; padding-left: 0px; margin-left: 0px; } #breadcrumbf ul li { display: inline; } #breadcrumbf li:first-child { background-image: none; padding-left: 0px; } #breadcrumbf li { background-image: url(images/arrow.gif); background-position: left; background-repeat: no-repeat; padding-left: 25px; }

- Markup
- Style

    <div id="breadcrumbf"><ul>
    <li><a href="http://dmoz.org/">Top</a></li>
    <li><a href="http://dmoz.org/Science/">Science</a></li>
    <li><a href="http://dmoz.org/Science/Biology/">Biology</a></li>
    <li><a href="http://dmoz.org/Science/Biology/Genetics/">Genetics</a></li>
    <li><a href="http://dmoz.org/Science/Biology/Genetics/Genomics/">Genomics</a></li>
    <li><span>Pharmacogenetics</span></li>
    </ul></div>

In `head` element:

    <link rel="stylesheet" type="text/css" href="example15.css"/>

In example15.css

    /*
      Order of pseudo-"a" elements:
      LoVe HAte (Link, Visited, Hover, Active
    */
     #breadcrumbf a:link, #breadcrumbf a:visited, #breadcrumbf a:hover, #breadcrumbf a:active, #breadcrumbf li span {
        color: navy;
        font-family: Tahoma, Arial, Helvetica, sans-serif;
        font-size: small;
        font-weight: normal;
        padding: 0.5em;
        text-decoration: none;
    }
    #breadcrumbf a:hover {
        text-decoration: underline;
    }
    #breadcrumbf li span {
        color: black;
    }
    #breadcrumbf ul {
        background-color: #ddd;
        padding-left: 0px;
        margin-left: 0px;
    }
    #breadcrumbf ul li {
        display: inline;
    }
    #breadcrumbf li:first-child {
        background-image: none;
        padding-left: 0px;
    }
    #breadcrumbf li {
        background-image: url(images/arrow.gif);
        background-position: left;
        background-repeat: no-repeat;
        padding-left: 25px;
    }

## CSS Rounded Borders

### CSS3 border-radius

Example 6.16 - CSS3 border-radius - Example 6.16 (Without Styles) | <div class="box rounded"><h3>Lorem Ipsum</h3><p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur dignissim volutpat diam, ac porttitor orci commodo sit amet. Sed ultrices arcu et lacus sagittis volutpat. Nam ac lectus est. Etiam eget erat lacus. Donec eget auctor tortor. Mauris sit amet lectus ullamcorper purus adipiscing porttitor sed ut lectus.</p></div><div class="box tightrounded"><h3>Lorem Ipsum</h3><p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur dignissim volutpat diam, ac porttitor orci commodo sit amet. Sed ultrices arcu et lacus sagittis volutpat. Nam ac lectus est. Etiam eget erat lacus. Donec eget auctor tortor. Mauris sit amet lectus ullamcorper purus adipiscing porttitor sed ut lectus.</p></div><div class="box looserounded"><h3>Lorem Ipsum</h3><p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur dignissim volutpat diam, ac porttitor orci commodo sit amet. Sed ultrices arcu et lacus sagittis volutpat. Nam ac lectus est. Etiam eget erat lacus. Donec eget auctor tortor. Mauris sit amet lectus ullamcorper purus adipiscing porttitor sed ut lectus.</p></div>.box { width: 260px; padding: 0 40px; border: 3px solid #009999; background-color: #CCFFFF; margin: 1em; } .rounded { border-radius: 25px; } .tightrounded { border-radius: 10px; } .looserounded { border-radius: 50px; }

- Markup
- Style
- Screenshot

     <div class="box rounded"><h3>Lorem Ipsum</h3><p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur dignissim volutpat diam, ac porttitor orci commodo sit amet. Sed ultrices arcu et lacus sagittis volutpat. Nam ac lectus est. Etiam eget erat lacus. Donec eget auctor tortor. Mauris sit amet lectus ullamcorper purus adipiscing porttitor sed ut lectus.</p>
    </div><div class="box tightrounded"><h3>Lorem Ipsum</h3><p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur dignissim volutpat diam, ac porttitor orci commodo sit amet. Sed ultrices arcu et lacus sagittis volutpat. Nam ac lectus est. Etiam eget erat lacus. Donec eget auctor tortor. Mauris sit amet lectus ullamcorper purus adipiscing porttitor sed ut lectus.</p>
    </div><div class="box looserounded"><h3>Lorem Ipsum</h3><p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur dignissim volutpat diam, ac porttitor orci commodo sit amet. Sed ultrices arcu et lacus sagittis volutpat. Nam ac lectus est. Etiam eget erat lacus. Donec eget auctor tortor. Mauris sit amet lectus ullamcorper purus adipiscing porttitor sed ut lectus.</p>
    </div>

In `style` element (`<style type="text/css">`) within `head` element:

    .box {
        width: 260px;
        padding: 0 40px;
        border: 3px solid #009999;
        background-color: #CCFFFF;
        margin: 1em;
    }
    .rounded {
         border-radius: 25px;
    }
    .tightrounded {
         border-radius: 10px;
    }
    .looserounded {
         border-radius: 50px;
    }

## What's with the "vendor prefixes"?

- Vendor Prefixes

    .rounded {
        border-radius: 20px 20px 20px 20px;
        -moz-border-radius: 20px 20px 20px 20px;
        -webkit-border-radius: 20px 20px 20px 20px;
        border: 3px solid #000000;
    }

## CSS Shadows

Photo by D Sharon Pruitt

- box-shadow (MDN)
- text-shadow (MDN)
- CanIUse: box-shadow? or text-shadow?

## box-shadow

- box-shadow (MDN)
- `box-shadow`: x-offset y-offset color

### CSS3 box-shadow

Example 6.17 - CSS3 box-shadow - Example 6.17 (Without Styles) | <div class="box shadow"><h3>Lorem Ipsum</h3><p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur dignissim volutpat diam, ac porttitor orci commodo sit amet. Sed ultrices arcu et lacus sagittis volutpat. Nam ac lectus est. Etiam eget erat lacus. Donec eget auctor tortor. Mauris sit amet lectus ullamcorper purus adipiscing porttitor sed ut lectus.</p></div>.box { width: 260px; padding: 0 40px; border: 3px solid #009999; background-color: #CCFFFF; } .shadow { -moz-box-shadow: 5px 5px #99cccc; -webkit-box-shadow: 5px 5px #99cccc; box-shadow: 5px 5px #99cccc; }

- Markup
- Style
- Screenshot

     <div class="box shadow"><h3>Lorem Ipsum</h3><p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur dignissim volutpat diam, ac porttitor orci commodo sit amet. Sed ultrices arcu et lacus sagittis volutpat. Nam ac lectus est. Etiam eget erat lacus. Donec eget auctor tortor. Mauris sit amet lectus ullamcorper purus adipiscing porttitor sed ut lectus.</p>
    </div>

In `style` element (`<style type="text/css">`) within `head` element:

    .box {
        width: 260px;
        padding: 0 40px;
        border: 3px solid #009999;
        background-color: #CCFFFF;
    }
    .shadow {
        -moz-box-shadow: 5px 5px #99cccc;
        -webkit-box-shadow: 5px 5px #99cccc;
        box-shadow: 5px 5px #99cccc;
    }

## Text Shadow

- text-shadow

Example 6.18 - CSS3 text-shadow - Example 6.18 (Without Styles) | <div><h3 class="shadow">Only the Shadow Knows</h3><p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur dignissim volutpat diam, ac porttitor orci commodo sit amet. Sed ultrices arcu et lacus sagittis volutpat. Nam ac lectus est. Etiam eget erat lacus. Donec eget auctor tortor. Mauris sit amet lectus ullamcorper purus adipiscing porttitor sed ut lectus.</p></div>h3.shadow { background-color: #eef; font-size: 24pt; padding: 0.25em; color: #900; /* offset-x | offset-y | blur-radius | color */ text-shadow: 3px 4px 4px rgba(150,150,150,0.5) }

- Markup
- Style
- Display
- Screenshot

    <div><h3 class="shadow">Only the Shadow Knows</h3><p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur dignissim volutpat diam, ac porttitor orci commodo sit amet. Sed ultrices arcu et lacus sagittis volutpat. Nam ac lectus est. Etiam eget erat lacus. Donec eget auctor tortor. Mauris sit amet lectus ullamcorper purus adipiscing porttitor sed ut lectus.</p>
    </div>

In `style` element (`<style type="text/css">`) within `head` element:

    h3.shadow {
      background-color: #eef;
      font-size: 24pt;
      padding: 0.25em;
      color: #900;
      /* offset-x | offset-y | blur-radius | color */
      text-shadow: 3px 4px 4px rgba(150,150,150,0.5)
    }

### Only the Shadow Knows

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur dignissim volutpat diam, ac porttitor orci commodo sit amet. Sed ultrices arcu et lacus sagittis volutpat. Nam ac lectus est. Etiam eget erat lacus. Donec eget auctor tortor. Mauris sit amet lectus ullamcorper purus adipiscing porttitor sed ut lectus.

## Opacity - RGBA - red, green, blue, alpha

A = alpha channel, used for opacity.
Values of 0 to 1, where 0 is fully transparent, 1 is fully opaque

Example 6.19 - CSS3 text-shadow - Example 6.19 (Without Styles) | <div class="opacity-demo"><p style="color: rgba(0,0,0,1)">Opacity of 1</p><p style="color: rgba(0,0,0,0.75)">Opacity of 0.75</p><p style="color: rgba(0,0,0,0.5)">Opacity of 0.5</p><p style="color: rgba(0,0,0,0.25)">Opacity of 0.25</p><p style="color: rgba(0,0,0,0)">Opacity of 0</p></div>.opacity-demo { background-image: url('http://cscie12.dce.harvard.edu/resources/images/satin.png'); color: white; } .opacity-demo p { font-size: 200%; font-weight: bold; font-family: helvetica,sans-serif;}

- Markup
- Style
- Display
- Screenshot

    <div class="opacity-demo"><p style="color: rgba(0,0,0,1)">Opacity of 1</p>
    <p style="color: rgba(0,0,0,0.75)">Opacity of 0.75</p>
    <p style="color: rgba(0,0,0,0.5)">Opacity of 0.5</p>
    <p style="color: rgba(0,0,0,0.25)">Opacity of 0.25</p>
    <p style="color: rgba(0,0,0,0)">Opacity of 0</p>
    </div>

In `style` element (`<style type="text/css">`) within `head` element:

    .opacity-demo {
      background-image: url('images/satin.png');
      color: white;
    }
    .opacity-demo p { font-size: 200%; font-weight: bold; font-family: helvetica,sans-serif;}

Opacity of 1

Opacity of 0.75

Opacity of 0.5

Opacity of 0.25

Opacity of 0

## CSS Gradients

- linear-gradient
- radial-gradient

## linear-gradient

- linear gradient

Example 6.20 - CSS3 Gradient - Example 6.20 (Without Styles) | <div class="highlight1"><p>linear-gradient(0deg,red,black)<br/>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur dignissim volutpat diam, ac porttitor orci commodo sit amet. Sed ultrices arcu et lacus sagittis volutpat. Nam ac lectus est. Etiam eget erat lacus. Donec eget auctor tortor. Mauris sit amet lectus ullamcorper purus adipiscing porttitor sed ut lectus.</p></div><div class="highlight2"><p>linear-gradient(90deg,red,black)<br/>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur dignissim volutpat diam, ac porttitor orci commodo sit amet. Sed ultrices arcu et lacus sagittis volutpat. Nam ac lectus est. Etiam eget erat lacus. Donec eget auctor tortor. Mauris sit amet lectus ullamcorper purus adipiscing porttitor sed ut lectus.</p></div><div class="highlight3"><p>linear-gradient(45deg,black,yellow)<br/>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur dignissim volutpat diam, ac porttitor orci commodo sit amet. Sed ultrices arcu et lacus sagittis volutpat. Nam ac lectus est. Etiam eget erat lacus. Donec eget auctor tortor. Mauris sit amet lectus ullamcorper purus adipiscing porttitor sed ut lectus.</p></div><div class="highlight4"><p>linear-gradient(90deg,red,white,blue)<br/>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur dignissim volutpat diam, ac porttitor orci commodo sit amet. Sed ultrices arcu et lacus sagittis volutpat. Nam ac lectus est. Etiam eget erat lacus. Donec eget auctor tortor. Mauris sit amet lectus ullamcorper purus adipiscing porttitor sed ut lectus.</p></div><div class="highlight5"><p>linear-gradient(90deg,red,orange,yellow,green,blue,indigo,violet)<br/>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur dignissim volutpat diam, ac porttitor orci commodo sit amet. Sed ultrices arcu et lacus sagittis volutpat. Nam ac lectus est. Etiam eget erat lacus. Donec eget auctor tortor. Mauris sit amet lectus ullamcorper purus adipiscing porttitor sed ut lectus.</p></div>.highlight1 { background-image: linear-gradient(0deg,red,black); color: white; line-height: 200%; } .highlight2 { background-image: linear-gradient(90deg,red,black); color: white; line-height: 200%; } .highlight3 { background-image: linear-gradient(45deg,black,yellow); color: white; line-height: 200%; } .highlight4 { background-image: linear-gradient(90deg,red,white,blue); color: white; line-height: 200%; } .highlight5 { background-image: linear-gradient(90deg, red,orange,yellow,green,blue,indigo,violet); color: white; line-height: 200%; }

- Markup
- Style
- Screenshot

     <div class="highlight1"><p>linear-gradient(0deg,red,black)<br/>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur dignissim volutpat diam, ac porttitor orci commodo sit amet. Sed ultrices arcu et lacus sagittis volutpat. Nam ac lectus est. Etiam eget erat lacus. Donec eget auctor tortor. Mauris sit amet lectus ullamcorper purus adipiscing porttitor sed ut lectus.</p>
    </div><div class="highlight2"><p>linear-gradient(90deg,red,black)<br/>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur dignissim volutpat diam, ac porttitor orci commodo sit amet. Sed ultrices arcu et lacus sagittis volutpat. Nam ac lectus est. Etiam eget erat lacus. Donec eget auctor tortor. Mauris sit amet lectus ullamcorper purus adipiscing porttitor sed ut lectus.</p>
    </div><div class="highlight3"><p>linear-gradient(45deg,black,yellow)<br/>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur dignissim volutpat diam, ac porttitor orci commodo sit amet. Sed ultrices arcu et lacus sagittis volutpat. Nam ac lectus est. Etiam eget erat lacus. Donec eget auctor tortor. Mauris sit amet lectus ullamcorper purus adipiscing porttitor sed ut lectus.</p>
    </div><div class="highlight4"><p>linear-gradient(90deg,red,white,blue)<br/>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur dignissim volutpat diam, ac porttitor orci commodo sit amet. Sed ultrices arcu et lacus sagittis volutpat. Nam ac lectus est. Etiam eget erat lacus. Donec eget auctor tortor. Mauris sit amet lectus ullamcorper purus adipiscing porttitor sed ut lectus.</p>
    </div><div class="highlight5"><p>linear-gradient(90deg,red,orange,yellow,green,blue,indigo,violet)<br/>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur dignissim volutpat diam, ac porttitor orci commodo sit amet. Sed ultrices arcu et lacus sagittis volutpat. Nam ac lectus est. Etiam eget erat lacus. Donec eget auctor tortor. Mauris sit amet lectus ullamcorper purus adipiscing porttitor sed ut lectus.</p>
    </div>

In `style` element (`<style type="text/css">`) within `head` element:

    .highlight1 {
      background-image: linear-gradient(0deg,red,black);
      color: white;
      line-height: 200%;
    }
    .highlight2 {
      background-image: linear-gradient(90deg,red,black);
      color: white;
      line-height: 200%;
    }
    .highlight3 {
      background-image: linear-gradient(45deg,black,yellow);
      color: white;
      line-height: 200%;
    }
    .highlight4 {
      background-image: linear-gradient(90deg,red,white,blue);
      color: white;
      line-height: 200%;
    }
    .highlight5 {
      background-image: linear-gradient(90deg, red,orange,yellow,green,blue,indigo,violet);
      color: white;
      line-height: 200%;
    }

## radial-gradient

- radial gradient

Example 6.21 - CSS3 Gradient - Example 6.21 (Without Styles) | <div class="highlight6"><p>circle, red, black<br/>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur dignissim volutpat diam, ac porttitor orci commodo sit amet. Sed ultrices arcu et lacus sagittis volutpat. Nam ac lectus est. Etiam eget erat lacus. Donec eget auctor tortor. Mauris sit amet lectus ullamcorper purus adipiscing porttitor sed ut lectus.</p></div><div class="highlight7"><p>ellipse red black<br/>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur dignissim volutpat diam, ac porttitor orci commodo sit amet. Sed ultrices arcu et lacus sagittis volutpat. Nam ac lectus est. Etiam eget erat lacus. Donec eget auctor tortor. Mauris sit amet lectus ullamcorper purus adipiscing porttitor sed ut lectus.</p></div><div class="highlight8"><p>circle,red,orange,yellow,green,blue,indigo,violet<br/>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur dignissim volutpat diam, ac porttitor orci commodo sit amet. Sed ultrices arcu et lacus sagittis volutpat. Nam ac lectus est. Etiam eget erat lacus. Donec eget auctor tortor. Mauris sit amet lectus ullamcorper purus adipiscing porttitor sed ut lectus.</p></div><div class="highlight9"><p>ellipse,red,orange,yellow,green,blue,indigo,violet<br/>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur dignissim volutpat diam, ac porttitor orci commodo sit amet. Sed ultrices arcu et lacus sagittis volutpat. Nam ac lectus est. Etiam eget erat lacus. Donec eget auctor tortor. Mauris sit amet lectus ullamcorper purus adipiscing porttitor sed ut lectus.</p></div>.highlight6 { background-image: radial-gradient(circle,red,blue); color: white; line-height: 200%; } .highlight7 { background-image: radial-gradient(ellipse,red,blue); color: white; line-height: 200%; } .highlight8 { background-image: radial-gradient(circle,red,yellow,green,blue,indigo,violet); color: white; line-height: 200%; } .highlight9 { background-image: radial-gradient(ellipse,red,yellow,green,blue,indigo,violet); color: white; line-height: 200%; }

- Markup
- Style
- Screenshot

     <div class="highlight6"><p>circle, red, black<br/>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur dignissim volutpat diam, ac porttitor orci commodo sit amet. Sed ultrices arcu et lacus sagittis volutpat. Nam ac lectus est. Etiam eget erat lacus. Donec eget auctor tortor. Mauris sit amet lectus ullamcorper purus adipiscing porttitor sed ut lectus.</p>
    </div><div class="highlight7"><p>ellipse red black<br/>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur dignissim volutpat diam, ac porttitor orci commodo sit amet. Sed ultrices arcu et lacus sagittis volutpat. Nam ac lectus est. Etiam eget erat lacus. Donec eget auctor tortor. Mauris sit amet lectus ullamcorper purus adipiscing porttitor sed ut lectus.</p>
    </div><div class="highlight8"><p>circle,red,orange,yellow,green,blue,indigo,violet<br/>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur dignissim volutpat diam, ac porttitor orci commodo sit amet. Sed ultrices arcu et lacus sagittis volutpat. Nam ac lectus est. Etiam eget erat lacus. Donec eget auctor tortor. Mauris sit amet lectus ullamcorper purus adipiscing porttitor sed ut lectus.</p>
    </div><div class="highlight9"><p>ellipse,red,orange,yellow,green,blue,indigo,violet<br/>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur dignissim volutpat diam, ac porttitor orci commodo sit amet. Sed ultrices arcu et lacus sagittis volutpat. Nam ac lectus est. Etiam eget erat lacus. Donec eget auctor tortor. Mauris sit amet lectus ullamcorper purus adipiscing porttitor sed ut lectus.</p>
    </div>

In `style` element (`<style type="text/css">`) within `head` element:

    .highlight6 {
      background-image: radial-gradient(circle,red,blue);
      color: white;
      line-height: 200%;
    }
    .highlight7 {
      background-image: radial-gradient(ellipse,red,blue);
      color: white;
      line-height: 200%;
    }
    .highlight8 {
      background-image: radial-gradient(circle,red,yellow,green,blue,indigo,violet);
      color: white;
      line-height: 200%;
    }
    .highlight9 {
      background-image: radial-gradient(ellipse,red,yellow,green,blue,indigo,violet);
      color: white;
      line-height: 200%;
    }

## Graphics and Images

## Graphics: Purpose

- Content
- Design

### Images and Markup

Two ways of including images:

1. Markup: `img` element
   - `alt` attribute
   - `height` and `width` attributes

       <img src="images/shield.png"
        alt="Harvard Veritas" height="328" width="281"/>

2. CSS: `background-image` property

       #header {
         background-image: url(images/shield.png);
         background-repeat: no-repeat;
       }

## Graphics Formats for the Web

PNG
  Portable Network Graphic
  `.png`
JPEG
  Joint Photographic Experts Group
  `.jpeg` or `.jpg`
GIF
  Graphics Interchange Format
  `.gif`
SVG
  Scalable Vector Graphics
  `.svg` and `.svgz`

### Other formats

Image formats you might encounter, but aren't super-relevant for the web:

- TIFF
- RAW
- JPEG 2000 (JP2)
- BMP

## file.jpg or file.JPG -- Does it matter?

- Yes. If your filename is "beach.JPG" then you need to reference it as "beach.JPG" -- having "beach.jpg" in the URL won't work!
- No. As long as the case of your filenames match the case in your URL references you'll be fine.

## Graphics: Vector and Bitmap

Bitmap | Vector
--- | ---
Original image (PNG): | Original image (SVG):
Magnified (16x) | Magnified (16x)
Bitmap formats: PNG, JPEG, GIF | Vector formats: SVG

## Colors

### RGB Color Space

256 colors in each channel (Red, Green, Blue). Values can be

- decimal numbers (0 to 255)
- hexadecimal numbers (00 to ff)
- percentages (0 to 100%)

## Color Depth

- RGB color is a 24-bit system (16 million colors)
- 8 bits (256 colors) for each channel (red, green, blue).

  28x28x28 = 2(8 + 8 + 8) = 224x = 16,777,216

Bits | Colors
--- | ---
1 | 21 = 2
2 | 22 = 4
3 | 23 = 8
4 | 24 = 16
5 | 25 = 32
6 | 26 = 64
7 | 27 = 128
8 | 28 = 256
16 | 216 = 65,536
24 | 224 = 17 x 106 (millions)
32 | 232 = 4.3 x 109

## Indexed Color Systems

An 8-bit indexed image has a palette of up to 256 colors that the image can contain. Color information is not stored for each pixel, but rather just a reference to which color in the palette.

Palettes

- Exact (if 256 or fewer colors)
- Adaptive (weighted based upon colors in document)
- Web Palette (216 Web Safe Colors)
- System
  - Windows
  - Macintosh

### But what happens to the other colors?

If you take a photo that is saved in an RGB system (millions of colors) and then convert it to an indexed system with 256 colors, what happens?

- dither
- color-shift

## Bitmap images: Size and Quality

Factors that contribute to image size:

- Dimension
- Compression
- Number of Colors

## Graphics Formats for the Web

Property | GIF Graphics Interchange Format | JPEG Joint Photographic Experts Group | PNG Portable Network Graphic | SVG Scalable Vector Graphics
--- | --- | --- | --- | ---
Color System | 8 bit indexed (256 colors) | RGB (24 bit; millions of colors) | 8 bit indexed (256 colors) RGB (24 bit; millions of colors) | 24 bit; millions of colors
Compression | Lossless Compression (LZW; horizontal repeating units) | "Lossy" Compression (compression optimized for gradual color changes) | Lossless Compression | Lossless Compression
Other Features | `.gif` file extension Transparency Animation | `.jpg` and `.jpeg` file extensions No Transparency No Animation | `.png` file extension Transparency | `.svg` file extension Vector-based Transparency XML format
Typical Uses | Illustrations (logos, icons) Animated banners and icons Images with small dimension | Photographs | Any | Illustrations Graphs, Charts, Maps - 'plain' and 'interactive'
Property | GIF Graphics Interchange Format | JPEG Joint Photographic Experts Group | PNG Portable Network Graphic | SVG Scalable Vector Graphics
Photograph 250 × 188 px | 29.3 kb | 16.8 kb | 25.8 kb (indexed, 8-bit) | 81.9 kb (RGB, 24-bit) | N/A
Illustration 148 × 179 px | 1.47 kb | 6.12 kb | 1.02 kb (indexed, 8-bit) | 1.89 kb (RGB, 24-bit) | 0.575 kb (compressed, 1.7 kb uncompressed; RGB, 24-bit)

Hot Air Balloon image is in the Public Domain and was obtained from PD Photo.

Illustration image from the original works of David Heitmeyer

## JPEG

Joint Photographic Experts Group

Property | JPEG Joint Photographic Experts Group
--- | ---
Color System | RGB (24 bit; millions of colors)
Compression | "Lossy" Compression (compression optimized for gradual color changes)
Other Features | `.jpg` and `.jpeg` file extensions No Transparency No Animation
Typical Uses | Photographs
Property | JPEG Joint Photographic Experts Group
Photograph 250 × 188 px | 16.8 kb
Illustration 148 × 179 px | 6.12 kb

## JPEG Compression

The amount of compression (quality of image) for a JPEG image can be chosen (from a scale of 0 to 100). The image quality is inversely related to the amount of compression since the compression algorithm is "lossy".

Properties | Image
--- | ---
Quality: 80 34.1 kb |
Quality: 70 26.0 kb |
Quality: 60 22.4 kb |
Quality: 50 17.0 kb |
Quality: 40 14.3 kb |
Quality: 30 6.97 kb |
Quality: 20 4.80 kb |
Quality: 10 3.75 kb |
Quality: 1 3.21 kb |

## JPEG Compression Artifacts

Typically first appears at boundaries in images. Portions of image can also become "blocky".

Schlieren at boundaries:

Blockyness

## GIF

Property | GIF Graphics Interchange Format
--- | ---
Color System | 8 bit indexed (256 colors)
Compression | Lossless Compression (LZW; horizontal repeating units)
Other Features | `.gif` file extension Transparency Animation
Typical Uses | Illustrations (logos, icons) Animated banners and icons Images with small dimension
Property | GIF Graphics Interchange Format
Photograph 250 × 188 px | 29.3 kb
Illustration 148 × 179 px | 1.47 kb

## Palettes

An 8-bit indexed image has a palette of up to 256 colors that the image can contain. Color information is not stored for each pixel, but rather just a reference to which color in the palette.

Palettes

- Exact (if 256 or fewer colors)
- Adaptive (weighted based upon colors in document)
- Web Palette (216 Web Safe Colors)
- System
  - Windows
  - Macintosh

## Palettes: Exact, Adaptive, Web 216

### Exact Palette
Image | Palette
--- | ---
### Adaptive Palette
Image | Palette
### Web 216 Palette
Image | Palette

## Adaptive Palette: Shift and Dither

### Color Shift

Image (16 colors; Color Shift) | Zoom
--- | ---

### Dither

Image (16 colors; Dither) | Zoom
--- | ---

## GIF Images and Bit Depth: Color Shift

Properties | Image | Palette (adaptive)
--- | --- | ---
8 bit 256 colors 46.3 kb |  |
7 bit 128 colors 36.2 kb |  |
6 bit 64 colors 28.9 kb |  |
5 bit 32 colors 21.9 kb |  |
4 bit 16 colors 16.5 kb |  |
3 bit 8 colors 10.9 kb |  |
2 bit 4 colors 7.31 kb |  |
1 bit 2 colors 2.84 kb |  |

## GIF Images and Bit Depth: Dither

Properties | Image | Palette (adaptive)
--- | --- | ---
8 bit 256 colors 64.9 kb |  |
7 bit 128 colors 52.3 kb |  |
6 bit 64 colors 43.4 kb |  |
5 bit 32 colors 34.7 kb |  |
4 bit 16 colors 26.7 kb |  |
3 bit 8 colors 18.6 kb |  |
2 bit 4 colors 14.2 kb |  |
1 bit 2 colors 5.86 kb |  |

## Compression for Indexed GIF

GIF LZW compression operates on horizontal blocks of the same color. Here are two images that are identical except for a 90 degree rotation. The vertical stripe GIF image is nearly twice as large as the horizontal stripe GIF image. The PNG images are the same size.

Format | Horizontal Stripes | Vertical Stripes
--- | --- | ---
GIF | 471 bytes | 911 bytes
PNG | 232 bytes | 221 bytes

## Compression and Dithering

A purple shade was created by alternating red and blue pixels.
32× magnification:

200×200px Image, Dithered and Solid
Image Format | Dithered Grid | Solid
PNG | 225 bytes | 209 bytes
GIF | 601 bytes | 303 bytes

## Transparency

With PNG images, a color in the palette can be designated as "transparent". This lets any background colors or background images show through the transparent portions.

Star Image

Background Image
(satin.png)

Format | Background Color (gray) | Background Image satin.png
--- | --- | ---
GIF No transparency |  |
GIF White is transparent |  |
GIF Blue is transparent |  |
PNG No transparency |  |
PNG White is transparent |  |
PNG Blue is transparent |  |

## GIF Animation

- GIF supports animation
- giphy.com

## PNG

Property | PNG Portable Network Graphic
--- | ---
Color System | 8 bit indexed (256 colors) RGB (24 bit; millions of colors)
Compression | Lossless Compression
Other Features | `.png` file extension Transparency Animation through non-standard extension
Typical Uses | Any
Property | PNG Portable Network Graphic
Photograph 250 × 188 px | 25.8 kb (indexed, 8-bit) | 81.9 kb (RGB, 24-bit)
Illustration 148 × 179 px | 1.02 kb (indexed, 8-bit) | 1.89 kb (RGB, 24-bit)

## Compression for Indexed PNG

PNG images use a different compression algorithm than GIF. Note that for PNG, the vertical and horizontal striped images are the same size.

Format | Horizontal Stripes | Vertical Stripes
--- | --- | ---
PNG | 232 bytes | 221 bytes
GIF | 471 bytes | 911 bytes

## Compression and Dithering

A purple shade was created by alternating red and blue pixels.
32× magnification:

200×200px Image, Dithered and Solid
Image Format | Dithered Grid | Solid
PNG | 225 bytes | 209 bytes
GIF | 601 bytes | 303 bytes

## Transparency

With PNG images, a color in the palette can be designated as "transparent". This lets any background colors or background images show through the transparent portions.

Star Image

Background Image
(satin.png)

Format | Background Color (gray) | Background Image satin.png
--- | --- | ---
GIF No transparency |  |
GIF White is transparent |  |
GIF Blue is transparent |  |
PNG No transparency |  |
PNG White is transparent |  |
PNG Blue is transparent |  |

## Animated PNG (APNG)

Animated PNG (APNG) not widely supported across browsers now.
Something to keep an eye on!

## SVG

Property | SVG Scalable Vector Graphics
--- | ---
Type | Vector
Color System | RGB
Compression | Lossless Compression
Other Features | `.svg` file extension Transparency XML format Uses CSS properties!
Typical Uses | Illustrations (logos, icons) Vector Art
Illustration 300x300px | 575 bytes compressed; 1.7 kb uncompressed

## Basic SVG Shapes

Basic Shapes in SVG 1.1

SVG:

    <?xml version="1.0" encoding="utf-8"?>
    <!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN"
      "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
    <svg width="300" height="200" xmlns="http://www.w3.org/2000/svg" version="1.1">
      <rect x="100" y="100" height="30" width="70" rx="10" ry="10"
        style="fill:green; stroke: black;"/>
      <circle cx="50" cy="20" r="15" style="fill:red; stroke: black;"/>
      <ellipse cx="60" cy="75" rx="15" ry="40" fill="yellow" stroke="black"/>
      <line x1="10" y1="3" x2="30" y2="70" stroke-width="5" stroke="magenta"/>
      <polyline fill="none" points="160,15,170,25,180,15,190,25,200,15,210,25,220,15"
        stroke="blue" stroke-width="3"/>
      <polygon points="100,80,150,40,200,60" fill="orange" stroke="black"/>
      <path d="M0 0 C 10 20, 30 20, 40 0" style="stroke: black; stroke-width: 3px; fill: transparent"  transform="translate(-20,-30)"/>
    </svg>

## United States Flag

## Harvard Division of Continuing Education Shield

## Massachusetts Map

Shaded according to 2012 senate race results by town.

## United Nations Flag

## SVG -- Increasing Importance in the Future

- Vector (size and resolution advantages)
- HTML5 `canvas` element
- CSS control
  - CSS stylesheets
  - SVG style attributes same/similar to CSS properties

## SVG and D3 JS Library

D3.js
D3.js is a JavaScript library for manipulating documents based on data. D3 helps you bring data to life using HTML, SVG, and CSS. D3’s emphasis on web standards gives you the full capabilities of modern browsers without tying yourself to a proprietary framework, combining powerful visualization components and a data-driven approach to DOM manipulation.

## Comparison of Image Formats

### Graphics Formats for the Web

Property | GIF Graphics Interchange Format | JPEG Joint Photographic Experts Group | PNG Portable Network Graphic | SVG Scalable Vector Graphic
--- | --- | --- | --- | ---
Color System | 8 bit indexed (256 colors) | RGB (24 bit; millions of colors) | 8 bit indexed (256 colors) RGB (24 bit; millions of colors) | RGB
Compression | Lossless Compression (LZW; horizontal repeating units) | "Lossy" Compression (compression optimized for gradual color changes) | Lossless Compression | Lossless (gzip)
Other Features | `.gif` file extension Transparency Animation | `.jpg` and `.jpeg` file extensions No Transparency No Animation | `.png` file extension Transparency Animation through APNG, but not widely supported | `.svg` file extension Transparency XML format Uses CSS properties!
Typical Uses | Illustrations (logos, icons) Animated banners and icons Images with small dimension | Photographs | Any | Illustrations (logos, icons) Vector Art
Property | GIF Graphics Interchange Format | JPEG Joint Photographic Experts Group | PNG Portable Network Graphic | SVG Scalable Vector Graphic
Photograph 250 × 188 px | 29.3 kb | 16.8 kb | 25.8 kb (indexed, 8-bit) | 81.9 kb (RGB, 24-bit) | N/A
Illustration 148 × 179 px | 1.47 kb | 6.12 kb | 1.02 kb (indexed, 8-bit) | 1.89 kb (RGB, 24-bit) | 0.6 kb

Hot Air Balloon image is in the Public Domain and was obtained from PD Photo.

Illustration image from the original works of David Heitmeyer

## Cartoon Art

GIF | PNG | JPEG | SVG
--- | --- | --- | ---
GIF 1,511 bytes | PNG; 8 bit 1,031 bytes | JPEG (Quality 100) 14,660 bytes | SVG 575 bytes (compresssed)
| PNG; 24 bit 1,944 bytes | JPEG (Quality 6) 1,530 bytes

Original image from the works of David P. Heitmeyer

## Working with Images

### Graphics Tools

- Adobe
  - Adobe Photoshop
  - Adobe Illustrator
  - P.S. I'm still mourning the demise of Fireworks
- Corel
  - PaintShop
  - CorelDRAW
- Gimp (Open Source)
- Pixlr (Web, Desktop, Mobile)
- Gravit
- Acorn
- Affinity Photo (Mac Only)
- Sketch

## Start with Original PSD/AI/etc. or High Resolution 24-bit PNG

- If you contract out: get the original/source files!
  Keep track of them!
  Make sure others know!
- Always start with the original file format (e.g. PSD, AI, etc.) or high-resolution 24-bit PNG.
- Size images accordingly!
  - Don't shrink full-resolution images by using "height" and "width" CSS
  - Don't enlarge images from smaller ones -- you can only go one way (larger to smaller)

## Gazebo Image

- gazebo - hi res PNG - 231 kb
- gazebo - 200px wide PNG - 21 kb
- gazebo - enlarge 200px to 800px - 349 kb
- gazebo - JPEG Quality 30 - 470 kb

### Do's and Don'ts - shrinking

Don't shrink image with style properties:

Do resize image in graphics program:

### Do's and Don'ts - enlarging

Don't enlarge images from smaller one:

Do start from high resolution source file or original file format:

### Do's and Don'ts - choose appropriate format

Don't use JPEG for illustrations (used Quality 44 to get to same size as 24-bit PNG of same dimensions):

Copyright © David Heitmeyer