html - how to make input width larger and above the plant when focusing it? -

I want the style of the input element on top-left. When I click on input or type the command , the width of the input is larger and it exceeds these elements.

After some searches, I do not know this approach to doing this is what I have tried:

Thanks for any help.

If you want to add a similar animation, you need to add an infection:

  #input-less {status: relative; Width: 200px; Transition: Ease of width in 100ms; }   
 If you want the menu overlying effect, you can use it as the following point:  
  
 HTML  <>  pre & lt; Div & gt; & Lt; Input type = 'text' / & gt; & Lt; Ul & gt; & Lt; Li & gt; Item 1 & lt; / li & gt; & Lt; Li & gt; ITEM2 & lt; / li & gt; & Lt; Li & gt; ITEM3 & lt; / li & gt; & Lt; / Ul & gt; & Lt; / Div & gt;   
 css  
  div {status: relative; } Input {status: Completed; Width: 300px; z-index: 1; Infections: Ease of 200m width; } Input: Focus {width: 500px; } Input: Focus + ul {opacity: 0; } Ul {list-style: none; Status: Completed; Left: 320px; Z-index: 0; Opacity: 1; Infection: 200 mms opacity easily out; } Ul, li {margin: 0; Padding: 0; } Ul, li {display: inline-block; Vertical-align: medium; }