In the "Select" field, a dotted rectangle is placed on the mouse

Question

My select block places a dotted rectangle when a mouse is selected in it. How can I clean this?

I saw a lot of people having the same problem, and taking their input, I updated my CSS with these properties, but didn't use it.

select::-moz-focus-inner { border: 0; outline: 0; } select{ color: #000; color: rgba(0,0,0,0); text-shadow: 0 0 0 #000; margin: 10em 10em; } select::-moz-focusring { color: transparent; text-shadow: 0 0 0 #000; } 

I am using Firefox 38.0 on Ubuntu 14.04

Answer 1

Applying css properties to select and option tags removed the dashed lines permanently ....

 select::-moz-focus-inner, option::-moz-focus-inner { border: 0; outline: 0; } select, option{ color: #000; color: rgba(0,0,0,0); text-shadow: 0 0 0 #000; margin: 10em 10em; } select::-moz-focusring, option::-moz-focusring { color: transparent; text-shadow: 0 0 0 #000; } 

Answer 2

Try it -

 select:-moz-focusring { color: transparent; text-shadow: 0 0 0 black; }