Make the first character Uppercase in CSS

Note that the ::first-letter selector does not work with inline elements, so it must be either block or inline-block, as follows:

.m_title {display:inline-block}
.m_title:first-letter {text-transform: uppercase}

There's a property for that:

a.m_title {
    text-transform: capitalize;
}

If your links can contain multiple words and you only want the first letter of the first word to be uppercase, use :first-letter with a different transform instead (although it doesn't really matter). Note that in order for :first-letter to work your a elements need to be block containers (which can be display: block, display: inline-block, or any of a variety of other combinations of one or more properties):

a.m_title {
    display: block;
}

a.m_title:first-letter {
    text-transform: uppercase;
}