Null/CSS

From XPUB & Lens-Based wiki

Styling your page with CSS

CSS - Cascading Style Sheets

HTML is not meant to style (inline syling: style="color:...") is old fashion and discouraged.

CSS is the preferred to way to style.


  • HTML tell the browser what content it should display
  • CSS tells the browser how to display that content.

css in your html page

  • CSS code goes inside the style tags <style> ... </style>
  • inside the head of the html page.
<!DOCTYPE html>
<html>
 <head>
   <style>

     body{
       background: #FF19DC;
       color: black;
       font-family: mono;
      } 

   </style>
</head>
</html>
<body></body>
</html>

anatomy of a css rule

Each CSS style sheet is made of several rules.

Each rule follows the syntax:


Basic-Anatomy-of-a-CSS-Rule1.png

Source: http://dabrook.org/resources/posters/

Example of a CSS rule

  • element: what element(s) is being styled e.g. div
  • property: what property of that element is being styled e.g. color
  • value: how the property is styled e.g. white
div {
      background: blue;
      color: white;
      width: 500px;
      height: 250px;
      font-size:30pt;
   }

Here we are styling all the div elements in the html page.

css properties

CSS Property reference https://developer.mozilla.org/en-US/docs/Web/CSS/Reference

Some properties.

  • color, background-color, width, height
  • border, box-shadow, list-style
  • margin, padding
  • transform, gradient, border-radius

Use some of these properties to style your page.

a separate CSS file

The CSS for a HTML page (or several pages) can stored outside that page, in css file.

To do that we need link the HTML file to the CSS file, using the tag link inside the html head.

<link href="style.css" rel="stylesheet" />
<!DOCTYPE html>
<html>
 <head>
 <link href="style.css" rel="stylesheet" /> 
</head>
<body>
....


display

  • none - turns off the display of the element.
  • inline - horizontal line of elements, but width and hide will be define by its content.
  • block - vertical stack of elements.
  • inline-block - horizontal line of elements, but they can have a width and height.

https://developer.mozilla.org/en-US/docs/Web/CSS/display



id and class attributes

Two of the most used attributes in HTML is id and class.

They are important to distinguish and group different elements. And become particularly important in CSS styling.

Note:

id

Ids cannot repeat in the same file.

Ids are used to distinguish tags

The symbol for id is: #

<p id="special">I am special paragraph</p>
<p>Just another paragraph.</p>
<p>More of the same.</p>

Note: Ids can server as a anchor (link) point within each page.

css id selector(for a specific element)

# is the symbol used to indicate an id.

if I write the rule:

p#special { transform: matrix(1.0, 2.0, 3.0, 4.0, 5.0, 6.0);}

Only the paragraph with id="special" will be effected by the rule above.

class

Classes can be used INFINITE TIMES in a file. They are used to group tags.

The symbol for class is: .

<div class="text">Aa</p>                                                           
<span class="text">Bbbbb</p>                                                           
<p class="text">Ccccccccccc</p>

css class selector(for a group of elements)

if I write the rule:

.text { background: blue;
        font-size:30pt;
        color: white; }

no matter what elements do have the class text, they will all be encompassed by this rule.



styling links

css uses a pseudo-class for the different states of a link

a:visited - a link the user has visited a:hover - a link when the user mouses over it a:active - a link the moment it is clicked

For each of them, normally a rule is written.

position

important

CSS property position chooses alternative forms to for position elements.

The most common are

  • relative - the position is determined in relation to its neighbors
  • absolute - the position is determined in relation to its ancestors elements or html page body, if has no parent elements.
  • fixed - like absolute, but often used to create a floating element that stays in the same position even after scrolling the page

See square examples in https://developer.mozilla.org/en-US/docs/Web/CSS/position

centering elements

http://www.w3.org/Style/Examples/007/center.en.html


css for typography

essential typography properties

  • font-size: body in pt, rest of elements in em
  • font-height: regular or bold
  • font-style
  • font-family
  • color
  • text-align
  • line-height
  • letter-spacing: increases or decreases the space between characters( negative values are allowed)
  • text-shadow

Example http://publicationstation.wdka.hro.nl/go/Alice.html

Using fonts

system fonts custom fonts
ready to use need to load or upload
limited set broad range
change slightly in each user's computer remain the same to all users
too familiar fresh

system fonts

System fonts are generic fonts.

  • Sans­serif
  • Serif
  • Monospace
  • Cursive

system fonts example

<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8" />
    <style>
body {
   font-size: 10pt;
}

p {font-family: cursive;
   font-size: 3em;
}

p.other {font-family: sansserif}

span.yetanother {font-family: monospace}
    </style>
  </head>
  <body>
    <p>Cursive generict font</p>
    <p class="other">Testig another generic font. 
      <span class="yetanother">And yet another one</span>
    </p>
  </body>
</html>


custom fonts

The @font-face CSS at-rule allows authors to specify online fonts to display text on their web pages. Mozilla @font-face

Web fonts formats

Different font formats exist:

  • Web Open Font Format (.woff)
  • TrueType/OpenType (.ttf/.otf)
  • Scalable Vector Graphics Fonts (.svg)

Currently, most browsers support these font formats, with the exception of .svg, that is only supported by Firefox. See Wikipidia article on Web fonts.

use a custom font

To use a custom font, the font file has to be stored somewhere, either locally (same folder as your site).

You can download a sample of display fonts from: http://publicationstation.wdka.hro.nl/displayfonts.zip Containing:Amatic-Bold.ttf, AmaticSC-Regular.ttf, GrandHotel-Regular.otf, Pacifico.ttf

try changing the following example with other custom font

<html>
<head>
  <style type="text/css">

    @font-face {
      font-family: "Pacifico";
      src: url("fonts/Pacifico.ttf");
    }
    
    h1 { font-family: "Pacifico", serif;
    font-weight: normal;
    }
  </style>
</head>
<body>
  <h1>This is a custom font.</h1>
</body>
</html>

fonts and licenses

We can use this fonts and even make a commercial (for which we receive money) website, using that font, without paying for the font.

It is not because the font is free (of charge), but because they are open.

They are released under a SIL Open Font License (OPF).

SIL license

http://scripts.sil.org/cms/scripts/page.php?site_id=nrsi&id=OFL_web

License:

  • allows fonts to be used, studied, modified and redistributed freely.
  • fonts, including any derivative works, can be bundled, embedded,

redistributed and/or sold with any software.

  • fonts and derivatives, however, cannot be released under any other type of license.
  • requirement for fonts to remain under this license does not apply

to any document created using the fonts or their derivatives.

Apache license

http://www.fontsquirrel.com/fonts/sinkin-sans

open fonts libraries

remote custom fonts

It is possible to use custom fonts, that are not stored locally, and instead "live" in a service like Google Fonts or Open Font Library.

This method is:

  • convenient
  • easier

but, on the down-side:

  • it takes more time to load the page
  • the font can be removed at any point by the service

remote custom font example

Using the font https://fontlibrary.org/en/font/barrio and following the "Use this font" instructions:

<html>
<head>
<link rel="stylesheet" media="screen" href="https://fontlibrary.org/face/barrio" type="text/css"/> 

  <style type="text/css">
    
    h1 {   font-family: 'BarrioRegular';
           font-weight: normal;
           font-style: normal; 
    font-size: 3em;
    }
  </style>
</head>
<body>
  <h1>This is a remote custom font.</h1>
</body>
</html>


Resources