CSS for revealing text on hover not working

Hey guys - I'm using the below text to try and reveal a text block placed behind an image to appear on hover. The code is working on my personal website, but when I try it on my clients website it only works when you are in edit mode. Anyone got any ideas? Thank you

@media only screen and (min-width: 640px){ 
#block-yui_3_17_2_1_1673492412284_3335 { 
opacity: 0; 
transition: opacity 1s 
} 

#block-yui_3_17_2_1_1673492412284_3335:hover { 
opacity: 1; 
transition: opacity 1s 
} 
}
 

Hi,

What is your site url? We can check easier

https://mandolin-spinach-fnj6.squarespace.com/

On the home page for the Embark image

pword: 1234

Thanks in advance

I have found that it works when I have no background colour on the text box, but doesn't when I have the colour

I see you figured it out?

Yes I did by complete luck! had to put the usual code twice for each box - one with "min-width" and then one with "max width" - any idea why this worked?

//Reveal Text - Embark//
@media only screen and (min-width: 640px){ 
#block-yui_3_17_2_1_1675062158984_28173 { 
opacity: 0 !important; 
transition: opacity 1s !important 
} 

#block-yui_3_17_2_1_1675062158984_28173:hover { 
opacity: 0.8 !important; 
transition: opacity 1s !important 
} 
}

@media only screen and (max-width: 640px){ 
#block-yui_3_17_2_1_1675062158984_28173 { 
opacity: 0 !important; 
transition: opacity 1s !important 
} 

#block-yui_3_17_2_1_1675062158984_28173:hover { 
opacity: 0.8 !important; 
transition: opacity 1s !important 
} 
}

I've been losing my mind trying to figure out what I was doing wrong. I got a piece of code from someone on "Inside the Square and I couldn't get it to work no matter what I tried. This solved it though.

Unfortunately, now I have to go back and fix every image in my portfolio!