transition

transition: margin-right 2s;

transition: margin-right 2s 0.5s;

transition: margin-right 2s ease-in-out;

transition: margin-right 2s ease-in-out 0.5s;

transition:
  margin-right 2s,
  color 1s;

transition: all 1s ease-out;

<section id="default-example">
  <div id="example-element">Hover to see<br />the transition.</div>
</section>

#example-element {
  background-color: #e4f0f5;
  color: #000;
  padding: 1rem;
  border-radius: 0.5rem;
  font: 1em monospace;
  width: 100%;
  transition: margin-right 2s;
}

#default-example:hover > #example-element {
  background-color: #909;
  color: #fff;
  margin-right: 40%;
}

Transitions 讓你可以定義元件在兩個狀態之間切換的轉場效果。兩個不同狀態可以使用虛擬類別定義，像是:hover 或 :active 亦或是 使用 JavaScript 設定的狀態變化。

/* Apply to 1 property */
/* property name | duration */
transition: margin-right 4s;

/* property name | duration | delay */
transition: margin-right 4s 1s;

/* property name | duration | timing function */
transition: margin-right 4s ease-in-out;

/* property name | duration | timing function | delay */
transition: margin-right 4s ease-in-out 1s;

/* Apply to 2 properties */
transition:
  margin-right 4s,
  color 1s;

/* Apply to all changed properties */
transition: all 0.5s ease-out;

/* Global values */
transition: inherit;
transition: initial;
transition: unset;

transition 屬性可以包含一個或多個轉場設定，每一項設定都以逗點分開。

每一項設定都描述著每一項屬性所對應的轉場效果（或是 all 及 none這兩個特殊值）。其包含了：

• 無或一個對應的屬性名稱。可以是：

  • 關鍵字 none
  • 關鍵字 all
  • 以 <custom-ident> 命名的 CSS 屬性。

• 無或一個 <single-transition-timing-function> 表示所使用的漸變函式。

• 無、一個或兩個 <time> 值。第一個值會被指派給 transition-duration，而第二個則被指派給 transition-delay。

當每個轉場設定不等長時，請參見 當 property values list 之間不等長時... 。簡而言之，多餘的描述(超過實際被執行的數量)會直接被忽略。

transition = 
  <single-transition>#  

<single-transition> = 
  [ none | <single-transition-property> ]  ||
  <time>                                   ||
  <easing-function>                        ||
  <time>                                   

<single-transition-property> = 
  all             |
  <custom-ident>  

<easing-function> = 
  <linear-easing-function>        |
  <cubic-bezier-easing-function>  |
  <step-easing-function>          

<linear-easing-function> = 
  linear      |
  <linear()>  

<cubic-bezier-easing-function> = 
  ease              |
  ease-in           |
  ease-out          |
  ease-in-out       |
  <cubic-bezier()>  

<step-easing-function> = 
  step-start  |
  step-end    |
  <steps()>   

<linear()> = 
  linear( [ <number> && <percentage>{0,2} ]# )  

<cubic-bezier()> = 
  cubic-bezier( [ <number [0,1]> , <number> ]#{2} )  

<steps()> = 
  steps( <integer> , <step-position>? )  

<step-position> = 
  jump-start  |
  jump-end    |
  jump-none   |
  jump-both   |
  start       |
  end         

CSS 轉場 有更多範例。

• CSS 轉場
• TransitionEvent