Hello,
You can try to use this code for logo:
.header-logo img {
max-width: 500px;
width: 370px;
height: 170px;
}
To remove white space at the bottom try to add margin value 0px in the row settings of your last element:
http://storage2.static.itmages.com/i/15/0514/h_1431619293_6246553_3e20638adf.png
Regards,
Eva Kemp.