Resize header

I uploaded a Picture/logo on the front page, but it’s too big, both the height and Width. I like the height and Width of my posts on the front page, but I would like to make the logo on top smaller. Can’t find the code to adjust the header. can I do this With plugins or code? My blog is currently in maintenance mode, so you will not be able to look at it?!


You can add this css code below using custom css plugin:

#masthead .site-branding img {
    width: 180px;

you can adjust the value of the width from the code above.

Thank you so much!!

My compliment for this theme.
Is perfect for crome and android mobile device but in Internet Explorer and Firefox the logo is not fit with the windows.