Font size change in Site Title, Tag line and Primary Menu for Laptops & Desk

Need help urgently. I am using Dazzling theme and I am trying to increase the font size of the Site Title, Tag Line and for the primary menu. The font size appears perfect in mobile phones and tabs. However, it looks very small in Laptops & desktops. Pls suggest.
I have searched online. This code is working for Site Title but it looks very big on mobile phones:
#logo a.navbar-brand{font-size: 40px;font-family: serif;}

This code is not working for Tag line: #logo .tagline {font-size: 12px; font-family: sans-serif;}
Can you suggest the code for Site Title, Tag Line and for the primary menu meant for laptops & desktops.
Look forward to receive help on this.

Hello there,

I hope you are doing well today.

You can use the following CSS code to change the font size by going to Appearance > Customize > Additional CSS and pasting it there.

.navbar > .container .navbar-brand {
    font-size: 28px;

/*Menu items*/
.navbar-default .navbar-nav > li > a {
    font-size: 18px;

.site-description {
    font-size: 17px;

Best Regards,

Thank you for your quick response. It worked…

Hi, there

Nice, to hear your problem is fixed:)
Now I will now close the topic and mark it as resolved.
Feel free to contact us again Thanks!