DIALOGUE BOX

width: 274px (including the heading/title)
min-height: 168px
border: 1px solid #FF9900
border-radius: 4px
background-color: #FFF
padding: 0 3px 3px
font: helvetica, normal, 14px #666
line-height: 24px
text-align: center

HEADER

height: 40px
gradient: top #FF6600, bottom #FF9900
border-top: 1px solid #FF6600
border-radius: 4px
font: helvetica, bold, 16px #FFF
text-align: left

BUTTON

height: 30px (including top border 1px and bottom border 1px)
width (large): 262px (including top left border 1px and right border 1px)
width (small): 128px (including top left border 1px and right border 1px)
padding-left and padding-right: 13px
font: helvetica, normal, 14px, #666
text-align: center
border: 1px solid #CCC
border-bottom: #B3B3B3
border-radius: 4px
gradient: top #FEFEFE, bottom #E7E7E7
margin: 3px

LIGHT BOX

background-color: #000
opacity: 60%

Please refer to the guidelines for complete styling details https://docs.google.com/document/d/11iH5YTSazCSYGPUkja673lxxywLWTDE2yCwl9ICRC-I/edit