Heading font won't go below 400 weighting

Site URL: https://bullfrog-dahlia-nx3a.squarespace.com/config/

Hello, 
I have installed the Open Sans Light font onto my site, but squarespace won't let me set the font weight to anything below 400. Open Sans Light default is 300. I have even tried to manually adjust the weight of the font to 300, as you will see from my code below. When I adjust it to 700, for example, the font weight will change, but it never changes if i change the weight to anything below 400. 

Please help. Sie: https://bullfrog-dahlia-nx3a.squarespace.com/config/pages 

@font-face {
font-family: 'Open Sans', sans-serif;font-weight: 300; 
src: url('FontURLhttps://static1.squarespace.com/static/602f14fc1f1de445374ac97a/t/606c0407ea77f86aefd31ca0/1617691655426/OpenSans-Light.ttf');
}

h1 {font-family: 'Open Sans', sans-serif;
font-weight: 300;}
h2 {font-family: 'Open Sans', sans-serif;}
h3 {font-family: 'Open Sans', sans-serif;}
h4 {font-family: 'Open Sans', sans-serif;}
p {font-family: 'Open Sans', sans-serif;}

Try this new code

@font-face {
font-family: 'Open Sans'; 
src: url('https://static1.squarespace.com/static/602f14fc1f1de445374ac97a/t/606c0407ea77f86aefd31ca0/1617691655426/OpenSans-Light.ttf');
}
h1 {font-family: 'Open Sans', sans-serif;
font-weight: 300;}
h2, h3, h4, p {font-family: 'Open Sans', sans-serif !important;}

Almost! It worked for about a minute then revert back to 400. So frustrating. Thank you though

On 5/4/2021 at 11:00 AM, RossDungey said:

Almost! It worked for about a minute then revert back to 400. So frustrating. Thank you though

 

Your site is private. We can't check.