background-image: 
    linear-gradient( 
    #3A67AB, 
    #E8F6FF);

background-image: 
    linear-gradient(top, 
    #3A67AB 0%, 
    #E8F6FF 100%);

background-image: 
    linear-gradient(270deg, 
    #3A67AB 0%, 
    #E8F6FF 100%);

prefix with -webkit-, -moz-, -ms- & -o-

background-image:
  linear-gradient(180deg, 
     rgba(255,255,255,0) 40%, 
     #ffffff 40%, 
     #ffffff 60%, 
     rgba(255,255,255,0) 60%),
  linear-gradient(90deg,  
     rgba(255,255,255,0) 40%, 
     #ffffff 40%, 
     #ffffff 60%, 
     rgba(255,255,255,0) 60%),
  linear-gradient(45deg,  
     rgba(255,255,255,0) 43%, 
     #ffffff 43%, 
     #ffffff 57%, 
     rgba(255,255,255,0) 57%),
  linear-gradient(135deg,  
     rgba(255,255,255,0) 43%, 
     #ffffff 43%, 
     #ffffff 57%, 
     rgba(255,255,255,0) 57%);
		

transparent = rgba(0,0,0,0) not rgba(255,255,255,0)

• prefix ‘linear-gradient’ with -webkit-, -moz-, -ms- & -o-
• keyword ‘transparent’ = rgba(0,0,0,0) so fades to grey
• create effects with color stops at same location
• create effects by adding multiple gradients, playing with position and size
• learn from others: Lea Verou's Gradients, Estelle Weyl's Gradients, and Estelle's Flags
• Use tools: John Allsopp's tool, Damian Galarza's tool, Colorzilla

• Chrome 3*
  Chrome 10
• Safari 4*
  Safari 5.1
• Firefox 3.6
   
• Opera 11.1
   
• Internet Explorer 10

Prefixed -webkit-, -moz-, -ms-, -o-

• Chrome 1
• Safari 1.2
• Firefox 0.9
• Opera 9
• IE 4* / IE 9

opacity: 1;

opacity: 0.75;

opacity: 0.5;

opacity: 0.25;

opacity: 0;

color: rgba(0, 0, 0, 1);
background-color: rgba(58, 103, 171, 1);

color: rgba(0, 0, 0, 0.75);
background-color: rgba(58, 103, 171, 0.75);

color: rgba(0, 0, 0, 0.5;
background-color: rgba(58, 103, 171, 0.5);

color: rgba(0, 0, 0, 0.25);
background-color: rgba(58, 103, 171, 0.25);

color: rgba(0, 0, 0, 0)
background-color: rgba(58, 103, 171, 0);

• Chrome 1
• Safari 1.2
• Firefox 0.9
• Opera 9
• IE 9

• Used in RGBA & HSLA colors

  rgba(58, 103, 171, 0.5);
  hsla(216, 49%, 45%, 0.5);
  

• Drop Shadows

  .trans {box-shadow: -10px 10px rgba(0,0,0,0.3);}
  .solid {box-shadow: -10px 10px #999;}

• Text Shadows

  .trans {text-shadow: 0 21px 1px rgba(0,0,0,0.3);}
  .solid {text-shadow: 0 21px 1px #999;}

Border on slides, code & showflakes

border-radius: 0;

border-radius: 20px;

border-radius: 50%;

• Chrome / Chrome 4
• Safari 3 / Safari 5
• Firefox 1 / Firefox 4
• 
  Opera 10.5
• 
  IE 9

% works correctly since Safari 5.1 and FF 4.0

:nth-child() 

:nth-last-child() 

:nth-of-type() 

:nth-last-of-type() 

:first-child 

:last-child 

:first-of-type 

:last-of-type 

:only-child 

:only-of-type 

:root

:empty

:not(:empty) 

• Chrome
• Safari
• Firefox
• Opera
• IE 9

• W3C working specificiation
• Browser support chart

tr:first-child,
tr:last-child {
  font-weight: bold;
}
tr:nth-child(even) {
  background-color: #CCC;
}
tr:nth-child(3) {
  color: #CCC;
}
tr:first-of-type,
tr:last-of-type{
  text-decoration:line-through;
}
tr:nth-of-type(odd) {
  background-color: #FFF;
}
tr:nth-of-type(4n) {
  color: #E2007A;
}
tr:nth-of-type(3n-1) {
  font-style: italic;
}

<div id="flakes"><i></i><i></i><i></i><i></i><i></i><i></i><i></i>...

i:nth-of-type(5n)    { height:30px; width:30px;}
i:nth-of-type(5n+1)  { height:24px; width:24px;}
i:nth-of-type(5n+2)  { height:10px; width:10px;}...

i:nth-of-type(3n)    { animation-delay: 2.3s;}
i:nth-of-type(3n+1)  { animation-delay: 1.5s;}
i:nth-of-type(3n+2)  { animation-delay: 3.4s;}

i:nth-of-type(7n)    { opacity: 0.5;}
i:nth-of-type(7n+1)  { opacity: 0.8;}
i:nth-of-type(7n+2)  { opacity: 0.3;} ...

i:nth-of-type(11n)   { animation-timing-function: ease-in-out;}
i:nth-of-type(11n+1) { animation-timing-function:ease-out;}
i:nth-of-type(11n+2) { animation-timing-function:ease;} ...
i:nth-of-type(11n+5) { animation-timing-function:cubic-bezier(0.2, 0.3, 0.8, 0.9);}

input[placeholder] { 
/* matches any input with a placeholder */}
input[type=email] {
/* exact match */}
abbr[title~=unicorn] { 
/* matches unicorn but not unicorns */}
abbr[title|=en] { 
/* matches en-us and en-uk */}
a[href^=mailto] { 
/* starts with */}
a[href$=pdf]{ 
/* ends in */}
abbr[title*=unicorn] { 
/* matches unicorn and unicorns */}

E:[att] /* have the attribute at all */

E:[att=val] /* exact */

E:[att~=val] /* val is a space separated word */

E:[att|=val] /* with a dash */

E:[att^=val] /* begins with val */

E:[att$=val]  /* ends with val */

E:[att*=val]  /* val is anywhere as a substring */
.

@media print{
  abbr[title]:after { 
    content: "(" attr(title) ")";
  }
  a[href^=http]:after { 
    content: "(" attr(href) ")";
  }
}

• E::before
• E::after
• E:enabled
• E:disabled
• E:checked
• input:valid
• input:invalid
• input:optional
• input:required
• ::selection
• E:target
• E:not(s)
• E > F Child
• E + F Adjacent sibling
• E ~ F sibling

• transform: translate(200px, 0)
• transform: rotate(360deg)
• transform: scale(1.5)
• transform-origin: -20px -20px

• Chrome
• Safari
• Firefox 3.5
• Opera 10.5
• IE 9
•   all with vendor prefix

Enables the transition of properties from one state to the next over a defined length of time

• transition-property: properties (or 'all') that transition
• transition-duration: s or ms it takes to transition
• transition-timing-function: bezier curve of transition
• transition-delay: s or ms before transition starts
• transition: shorthand for 4 transition properties

• Chrome
• Safari
• Firefox 4
• Opera 10.5
• IE 10
•   all with vendor prefix

code {
   color: #000000;
   font-size: 100%;
   background-color: rgba(255,255,255,0.4);
   transition: all 0.5s ease-in 50ms;
}
code:hover {
   color: #E2007A;
   font-size: 120%;
   background-color: rgba(255,255,255,0.8);
}

code {
   transition: color, font-size, background-color 0.5s ease-in 50ms;
}

@keyframes falling {
    from {
      top: -40px;
    }
    to {
      top: 1000px;
    }
}

same as

@keyframes falling {
    0% {
      top: -40px;
    }
    100% {
      top: 1000px;
    }
}

Don't forget the %

Don't forget the 100%

Don't quote the animation name

@keyframes falling {

    0% {
      top: -40px;
    }
    
    10% {
      top: 400px;
    }
    
    90% {
      top: 560px;
    }

    100% {
      top: 1000px;
    }

}

@keyframes fallingAndDimming {

    0% {
      top: -40px;
      opacity: 1;
    }
    
    50% {
      opacity: 0.5;
    }

    100% {
      top: 800px;
      opacity: 1
    }

}
	

@keyframes leftright {

    0%, 30%, 100% {
      -webkit-transform: translateX(-80px);
    }
    
    50%, 80% {
      -webkit-transform: translateX(40px);
    }
}

@-webkit-keyframes falling {

    0%{
      -webkit-transform: translateY(0);	
    }

    100% {
       -webkit-transform: translateY(1000px);
    }
}

@-moz-keyframes falling {

    0%{
      -moz-transform: translateY(0);	
    }

    100% {
       -moz-transform: translateY(1000px);
    }

}

@-webkit-keyframes falling {

    0%{
      -webkit-transform: translateY(0) 
            rotate(0deg) 
     scale(0.9, 0.9);	
    }

    100% {
       -webkit-transform: translateY(1000px) 
             rotate(360deg) 
       scale(1.1, 1.1);
    }

}

-webkit- | -moz-

@-webkit-keyframes falling {
    
    0%{
      -webkit-transform: translateY(0) 
            rotate(0deg) 
     scale(0.9, 0.9);	
    }
    
    100% {
       -webkit-transform: translateY(1000px) 
             rotate(360deg) 
       scale(1.1, 1.1);
    }
}

.snowflake {
    -webkit-transform-origin: left -20px;
    -moz-transform-origin: left -20px;
    }

-webkit- | -moz-

@-webkit-keyframes falling {

    0%{
      -webkit-transform: translate3d(0, 0, 0) 
            rotate(0deg) 
            scale(0.9, 0.9);	
    }

    100% {
       -webkit-transform: translate3d(0, 1000px, 0) 
             rotate(360deg) 
             scale(1.1, 1.1);
    }

}

-webkit- | -moz-

.snowflake {
  display: inline-block;
  height: 20px;
  width: 20px;
  background-image:
    -webkit-linear-gradient(180deg, transparent 35%, #fff 40%, #fff 60%, transparent 65%),
    -webkit-linear-gradient(90deg, transparent 35%, #fff 40%, #fff 60%, transparent 65%),
    -webkit-linear-gradient(45deg, transparent 35%, #fff 40%, #fff 60%, transparent 65%),
    -webkit-linear-gradient(135deg, transparent 35%, #fff 40%, #fff 60%, transparent 65%);
  background-image:
    -moz-linear-gradient(180deg, transparent 35%, #fff 40%, #fff 60%, transparent 65%),
    -moz-linear-gradient(90deg, transparent 35%, #fff 40%, #fff 60%, transparent 65%),
    -moz-linear-gradient(45deg, transparent 35%, #fff 40%, #fff 60%, transparent 65%),
    -moz-linear-gradient(135deg, transparent 35%, #fff 40%, #fff 60%, transparent 65%);
  border-radius: 50%;
  -webkit-transform-origin: left -20px;
}

.snowflake {
   ...
   -webkit-transform-origin: left -20px;
   -webkit-animation-name: falling; 
   
   -moz-transform-origin: left -20px;
   -moz-animation-name: falling; 
}

.snowflake {
  ...
  -webkit-transform-origin: left -20px;
  -webkit-animation-name: falling; 
  -webkit-animation-duration: 3s;
  
  -moz-transform-origin: left -20px;
  -moz-animation-name: falling; 
  -moz-animation-duration: 3s;
}

.snowflake {
   …
  -webkit|moz-transform-origin: left -20px;
  -webkit|moz-animation-name: falling; 
  -webkit|moz-animation-duration: 3s;
  -webkit-animation-timing-function: ease-in-out;
  -moz-animation-timing-function: ease-in-out;
}

ease
linear
ease-in 
ease-out 
ease-in-out  
step-start
step-end 
steps( X[, start | end ]) 
cubic-bezier(x1, y1, x2, y2)

.snowflake {
   …
  -webkit|moz-transform-origin: left -20px;
  -webkit|moz-animation-name: falling; 
  -webkit|moz-animation-duration: 3s;
  -webkit|moz-animation-timing-function: ease-in-out;
  -webkit-animation-iteration-count: infinite;
  -moz-animation-iteration-count: infinite;
}

‘infinte’ or number. Default is ‘1’.

-webkit-animation-iteration-count: 3;
-moz-animation-iteration-count: 3;

.snowflake {
  …
  -webkit|moz-transform-origin: left -20px;
  -webkit|moz-animation-name: falling; 
  -webkit|moz-animation-duration: 3s;
  -webkit|moz-animation-timing-function: ease-in-out;
  -webkit|moz-animation-iteration-count:infinite;
  -webkit-animation-delay: 2s;
  -moz-animation-delay: 2s;
}

.snowflake {
  …
  -webkit|moz-transform-origin: left -20px;
  -webkit|moz-animation-name: falling; 
  -webkit|moz-animation-duration: 3s;
  -webkit|moz-animation-timing-function: ease-in-out;
  -webkit|moz-animation-iteration-count:infinite;
  -webkit|moz-animation-delay: 2s;
  -webkit-animation-direction: normal;
  -moz-animation-direction: normal;
}

Two possible values: normal | alternate;

-webkit-animation-direction: alternate;
-moz-animation-direction: alternate;

.snowflake {
  …
  -webkit|moz-animation-name: falling; 
  -webkit|moz-animation-duration: 3s;
  -webkit|moz-animation-timing-function: ease-in-out;
  -webkit|moz-animation-iteration-count:infinite;
  -webkit|moz-animation-delay: 2s;
  -webkit|moz-animation-direction: normal;
}

. . . can also be written as . . .

.snowflake {
  ...
  -webkit-animation: falling 3s ease-in-out 2s infinite;
  -moz-animation: falling 3s ease-in-out 2s infinite;
}

values: none | forwards | backwards | both

.snowflake {
  -webkit|moz-animation-name: falling; 
  -webkit|moz-animation-duration: 3s;
  -webkit|moz-animation-timing-function: ease-in-out;
  -webkit|moz-animation-iteration-count: 3;
  -webkit|moz-animation-delay: 5s;
  -webkit-animation-fill-mode: forwards;
  -webkit|moz-animation-fill-mode: forwards;
}

. . . or . . .

.snowflake {
 -webkit-animation: falling 3s ease-in-out 2s 3  forwards;
 -moz-animation: falling 3s ease-in-out 2s 3  forwards;
}

-webkit-animation-play-state: paused | running
-moz-animation-play-state: paused | running

.snowflake:hover {
  -webkit-animation-play-state: paused;
  -moz-animation-play-state: paused;
  }

• animationstart
• animationend
• animationiteration

el.addEventListener( 'webkitAnimationEnd', 
    function( event ) {
        console.log('Animation Ended'); 
    }, false );

• webkitAnimationStart
• webkitAnimationEnd
• webkitAnimationIteration

el.addEventListener( 'webkitAnimationEnd', 
    function( event ) {
        el.removeClassName('newClass'); 
        setTimeout("el.addClassName('newClass')", 100ms) 
    }, 
    false );