Highlight selected email in Outlook by fluffylynx

/* ==UserStyle==
@name           Highlight selected email in Outlook
@namespace      userstyles.world
@version        1.0.0
@description    Add subtle borders to selected email so it is distinct from pinned + flagged complete emails.
==/UserStyle== */
@-moz-document domain("outlook.office.com") {
    [aria-label="Message list"] [aria-selected="true"] {
        border-color: #acf;
        border-style: solid;
        border-width: 2px 0 2px 0;
    }
    [aria-label="Message list"] [aria-selected="true"] > *:first-child {
        margin-top: -2px;
        margin-bottom: -1px;
    }
}