html - css animation from current position(unknown) to bottom: 0% -

i have image sticking out of bottom of screen. want slide image using css animation.

the problem image dimensions vary depending on size of window. not know how of image sticking out of screen.

simply want move image bottom: 0%

so code similar except don't know starting percentage (i don't know it's -35%).

@-moz-keyframes moveupimage {     0% { bottom: -35% }     100% { bottom: 0% } } 

is there way tell css want animation go starting/current position bottom: 0% ?

if want css animation current position of element bottom use css transitions, doing way need apply bottom position , animation take place. (probably using position absolute).