Return to Answer

@import url('https://fonts.googleapis.com/css?family=Open+Sans');

html, body, h1, h2, h3, h4, p, a, ul, ol {
    font-family: 'Open Sans', sans !important;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

p {
    line-height: 1.5em;
}

#question-header .question-hyperlink {
    font-family: 'Open Sans', sans !important;
}

@import url('https://fonts.googleapis.com/css?family=Open+Sans');

html, body, h1, h2, h3, h4, p, a, ul, ol, li, input, textarea {
    font-family: 'Open Sans', sans !important;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

p {
    line-height: 1.5em;
}

#question-header .question-hyperlink {
    font-family: 'Open Sans', sans !important;
}

@import url('https://fonts.googleapis.com/css?family=Open+Sans');

html, body, h1, h2, h3, h4, p, a {
    font-family: 'Open Sans', sans !important;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

p {
    line-height: 1.5em;
}

#question-header .question-hyperlink {
    font-family: 'Open Sans', sans !important;
}

@import url('https://fonts.googleapis.com/css?family=Open+Sans');

html, body, h1, h2, h3, h4, p, a, ul, ol {
    font-family: 'Open Sans', sans !important;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

p {
    line-height: 1.5em;
}

#question-header .question-hyperlink {
    font-family: 'Open Sans', sans !important;
}

Example of the homepage:

Full size

Example of the homepage with dark mode (external extension) turned on:

Full size