MediaWiki talk:Common.css

read page widths

/* adjust viewing widths */
/* Styles for standard view */
.skin-standard .mw-body {
    max-width: 900px;    /* Adjust this value as needed */
    min-width: 600px;    /* Adjust this value as needed */
    margin: 0 auto;
    padding: 0 20px;
}

/* Styles for wide view */
.skin-wide .mw-body {
    max-width: 1200px;   /* Adjust this value as needed */
    min-width: 800px;    /* Adjust this value as needed */
    margin: 0 auto;
    padding: 0 20px;
}

/* Apply consistent width to the content area */
.mw-body {
    flex: 1;  /* Allow content to take up available space */
}

/* Styles to ensure sidebar does not affect the width */
#mw-content-text {
    box-sizing: border-box;  /* Include padding and border in the element's width and height */
} [[User:Michael Bromley|Michael Bromley]] ([[User talk:Michael Bromley|talk]]) 02:21, 31 January 2025 (UTC)

this limits the text area only but on both standard and wide views:

/* limit standard width */
.mw-content-container {
    max-width: 900px;
    margin: 0 auto;
}

this limits the entire width of the entire page:

.vector-feature-limited-width-clientpref-0,
.vector-feature-limited-width-content-disabled {
    max-width: 900px;
    margin: 0 auto;
}

THIS WORKS !!

.vector-feature-limited-width-clientpref-1 .mw-content-container {
    max-width: 900px;
    margin: 0 auto;
}