OK - Its not so difficult. The option of styling the login page was exactly that - an option to make the log in page look exactly the way you want it, in other words you can force it to look like a front page, or like a standard webpage, or like anything else you want.
But here's another option if you want to hide the navigation block on the front page, although it does involve a little bit of coding.
Not knowing what theme you are using or what Moodle version, this example uses Arialist in 2.3 (I actually did it first in my own krystle theme on 2.4.1, but I wanted to give an example from a core theme)
In frontpage.php add the highlighted lines:
$bodyclasses = array();
if ($showsidepost) {
$bodyclasses[] = 'side-post-only';
} else if (!$showsidepost) {
$bodyclasses[] = 'content-only';
}
if ($hascustommenu) {
$bodyclasses[] = 'has-custom-menu';
}
if (!isloggedin() {
$bodyclasses[]='notloggedin';
}
At the end of core.css add
.notloggedin .block_navigation {display:none;}
Note - if this is the only block in the column, it may leave you with an empty column but giving the space for the column as Moodle will detect that there should be a block there, its just being hidden by the css. This is not an issue if other blocks are used in that column, but may need a bit more fiddling with to find a better solution if Navigation is the only one you have there.
HTH
Richard