带有CSS @HTML最大宽度的HTML无法正常工作

Question

When using brackets to code my website, the @media worked and would make divs appear and disappear to support mobile screens. But after uploading to my hosting site, it does not work and all the elements are showing at once. How can I fix this? The relevant CSS code is below.

CSS:

@media (max-width : 720px) {
    .disappear {
        display: none;
    }
    #menuposition {
        margin-left: auto;
        margin-right: auto;
    }
    .galleryitem {
        width: 100%
    }
    .containergallery {
        max-width: 250px;
        padding-top: 0%;
    }
}
@media (min-width : 721px) {
    .reappear {
        display: none;
    }
    #menuposition {
        right: 0px;
        position: absolute;
    }
}
@media (max-width : 960px) {
    .galleryitem {
        width:100%
    }
    .containergallery {
        max-width: 300px;
        padding-top: 10px;
    }
}

Answer 1

That page you linked to doesn't have that CSS in the source anywhere and none of the linked files have it either.

Link the CSS to the page or place it in an inline-style element.