Adding a tab (spaces) with a /-

I’m pretty much new at CSS, so please forgive my ignorance.

Here is my current accordion code that adds the +/- icon and changes the color.

.accordion-title:after {
color:Red;
content: “+”;
float: left;
}
.accordion-title.open:after {
content: “\2212”;
}

However, I’d like to add a tab (5-10 spaces), between the +/- icon and the text and I’m unable to figure out.

Example
+ (5-10 spaces) Do you know the Muffin man?
– (5-10 spaces) Is he the one who lives on Mullberry lane?

Any suggestions?
Thanks

https://wordpress.org/plugins/accordion-shortcodes/