html - How to get full height to windows for fixed panel <div> -

i have left , right panel in layout in html. left panel position fixed , right panel absolute , scroll-able. want left panel fill color height of window fixed. how make left panel fill color bottom of window.

because don't know html structure nor css code, tried "mimic" situation since didn't provided code, should of had done wonder how question still alive , haven't been deleted.

however may achieve using 1 of following methods:

1. set height:100% left panel this
   js fiddle 1

   #left-panel { height:100%; position: fixed;} 

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2. making use of viewport units vh , vw, 100vh full window height, this: js fiddle 2

   #left-panel { height:100vh; position: fixed; } 

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3. you can set top:0 , bottom:0 instead of setting height property, this:
   js fiddle 3

   #left-panel { top:0; bottom:0; position: fixed; }