am stuck in challenge 1 since monday morning when the challenge kickstart.......

Step 6
The BUTTON with ID of oracle should have 2.5em top margin, solid 1px border, and occupy the available horizontal space.

this is the css i wrote:

#oracle {
margin: 2.5em 0 0 0;
border:1px solid;
width: 100%;
}

The error am getting: The #oracle button does not have specified css style....

I dont know what i did wrong... i have reset the google chrome browser and restarting the challenge like six times....
still not advance to the next stage.... i have been at it since 11pm yesterday....