Hello,
Without store url I am not able to send you the exact class or id of your page. But can suggest you the way. You may find your tag in inspect element [Right click on your site page > Find option inspect > search for body tag in inspect html] and can use a class which is template specific.
For example : On product page there might be class ‘template-product’ added or on cart page there might be class ‘template-cart’ added.
This is theme specific so you have to check it or send me url of the page so I can give yout the exact class. After finding class place it before this css.
For example -
.template-product h1.collection-hero__title {
font-size: 25px;
text-align: center;
}
.template-product .collection-hero{
background: #EDE0E0;
}