Having issues highlighting some pages

For some reason I can’t seem to get all of my pages to highlight the current page. The home and about pages seem to work fine, but not the others:

https://www.nogymfitness.com

Here is the code:

<li<?php if ( is_page(‘no-gym-fitness’)) { echo ‘ class=”current_page_item”‘; } ?>>HOME
<li<?php if ( is_page(‘about’)) { echo ‘ class=”current_page_item”‘; } ?>>ABOUT
<li<?php if ( is_page(‘fitness-programs’)) { echo ‘ class=”current_page_item”‘; } ?>>FITNESS PROGRAMS
<li<?php if ( is_page(‘rates’)) { echo ‘ class=”current_page_item”‘; } ?>>RATES
<li<?php if ( is_page(‘press’)) { echo ‘ class=”current_page_item”‘; } ?>>PRESS
<li<?php if ( is_page(‘success-stories’)) { echo ‘ class=”current_page_item”‘; } ?>>SUCCESS STORIES
<li<?php if ( is_page(‘fit-blog’)) { echo ‘ class=”current_page_item”‘; } ?>>FIT BLOG
<li<?php if ( is_page(‘faq’)) { echo ‘ class=”current_page_item”‘; } ?>>FAQ

CSS:
.current_page_item {
color: #64101A!important;
text-decoration: underline;
}

.current_page_item a, .current_page_item a:hover {
display: block;
text-decoration: underline;
color: #64101A!important;
}

Any help would be greatly appreciated!!