The font-size of the textarea that accepts SQL queries on my phpMyAdmin installation is too small. One workaround I found is to increase the minimum font size i
Find your phpMyAdmin directory.
cd themes
You may see more than one theme, and you want to make changes in the theme you are using -- phpMyAdmin lets you choose your theme. I use the original theme, so I made changes there.
Go to the css directory of the theme
cd original/css /* or your preferred theme */
Use a text editor like nano to modify theme_right.css.php
nano theme_right.css.php
Search for 2 style definitions
.CodeMirror pre
.CodeMirror textarea
Both will show "font-size: inherit" or font-size:inherit!important
Change to
font-size: 16px; /* or whatever you prefer */
Save and reload phpMyAdmin Note that you may need to clear your browser cache for these changes to appear.
On phpmyadmin 4.9.5 just change the ".Codemirror" in:
\phpMyAdmin\js\vendor\codemirror\lib\codemirror.css
add:
font-size: 1.5em; /* add this line to what font size you want */
Also change the file: "common.css.php" in:
\phpMyAdmin\themes\your_theme\css\common.css.php
in that file search for and add:
textarea,
tt,
pre,
code {
font-family: <?php echo $GLOBALS['cfg']['FontFamilyFixed']; ?>;
font-size: 1.5em; /* add this line to what font size you want */
}
And that should do it!
With this you will see a better size font on query textarea when edit and to view the query when you are not editing.
on phpmyadmin 4.6 found the ".Codemirror pre" in :
themes/theThemeUsed/js/codemirror/lib/codemirror.css
Click on the Home button under phpmyadmin in left:

Then you can change theme and font size.
I Had the same problem using phpMyAdmin with xampp.
to fix, go to
xampp > phpMyAdmin > themes > pmahomme > css
open the following file with your text editor
codemirror.css.php
and add the following line to the very bottom of the file
.CodeMirror pre {font-size:1.4em;}
Now save the file and that should do it!
(if phpMyAdmin is using a different theme to pmahomme then just add that line
of code to every codemirror.css.php file you can find!
If you are using "phpmyadmin 4.8.1" then go to xampp\phpMyAdmin\js\vendor\codemirror\lib,
open codemirror.css,
find font-size: inherit; and replace it with font-size: 2em;