JohnB Below is the CSS code I use. Stolen from here and looks the same: https://dellzhackintosh.github.io/fluent-flarum/
:root {
--primary-color: #0078d4;
--secondary-color: #0078d4;
--body-bg: #17222a;
--body-bg-shaded: #121a20;
--body-bg-light: #202f3a;
--body-bg-faded: rgba(23,34,42,0.93);
--text-color: #ddd;
--link-color: #0078d4;
--heading-color: #ddd;
--muted-color: #6c8293;
--muted-color-light: #8a9ba8;
--muted-color-dark: #000;
--shadow-color: rgba(0,0,0,0.5);
--control-bg: #1b2228;
--control-bg-light: #212a31;
--control-bg-shaded: #12181c;
--control-color: #6c8293;
--error-color: #d83e3e;
--text-on-dark: #fff;
--text-on-light: #141a1f;
--yiq-threshold: 108;
--header-bg: #091a27;
--header-color: #0078d4;
--header-control-bg: #1b2228;
--header-control-color: #6c8293;
--overlay-bg: rgba(10,13,15,0.9);
--code-bg: #0e1215;
--code-color: #fff;
--alert-bg: #fff2ae;
--alert-color: #ad6c00;
--alert-error-bg: #d83e3e;
--alert-error-color: #fff;
--alert-success-bg: #b4f1af;
--alert-success-color: #33722d;
--switch-on-color: #58a400;
--switch-off-color: #d0021b;
--enabled-color: #2ECC40;
--disabled-color: #FF4136;
--validation-error-color: #d83e3e;
--avatar-bg: var(--control-bg);
--badge-bg: var(--muted-color);
--badge-color: #fff;
--badge-hidden-bg: #888;
--usercard-bg: var(--control-bg);
--hero-bg: #1b2228;
--hero-color: #6c8293;
--tooltip-bg: rgba(0,0,0,0.9);
--tooltip-color: #fff;
--online-user-circle-color: #7fba00;
--discussion-title-color: #84898c;
--discussion-list-item-bg-hover: #192229;
--button-color: #6c8293;
--button-bg: #1b2228;
--button-bg-hover: #101518;
--button-bg-active: #060809;
--button-bg-disabled: #1b2228;
--button-primary-color: #17222a;
--button-primary-bg: #0078d4;
--button-primary-bg-hover: #006abb;
--button-primary-bg-active: #005ba1;
--button-primary-bg-disabled: #0078d4;
--control-danger-color: #a88;
--control-danger-bg: #411;
--control-danger-bg-hover: #300c0c;
--control-danger-bg-active: #1b0707;
--control-danger-bg-disabled: #411;
--muted-more-color: #5c6770;
--muted-more-bg: rgba(92,103,112,0.3);
--muted-more-bg-hover: rgba(80,90,98,0.35);
--muted-more-bg-active: rgba(69,78,84,0.4);
--muted-more-bg-disabled: rgba(92,103,112,0.3);
--button-inverted-color: #6c8293;
--button-inverted-bg: #17222a;
--button-inverted-bg-hover: #0e151a;
--button-inverted-bg-active: #050709;
--button-inverted-bg-disabled: #17222a;
--light-content-color: #fff;
--light-content-control-color: #fff;
--light-content-control-bg: rgba(0,0,0,0.1);
--light-content-control-bg-shaded: rgba(0,0,0,0.2);
--light-content-control-bg-fadedin: rgba(0,0,0,0.15);
--header-colored-color: #0078d4;
--header-colored-control-color: #6c8293;
--header-colored-control-bg: #1b2228;
--header-colored-control-bg-shaded: #101518;
--header-colored-control-bg-fadedin: #1b2228;
--border-radius: 4px;
--drawer-width: 270px;
--pane-width: 400px;
--header-height: 52px;
--header-height-phone: 46px;
--zindex-header: 1000;
--zindex-pane: 1010;
--zindex-composer: 1020;
--zindex-dropdown: 1030;
--zindex-modal-background: 1040;
--zindex-modal: 1050;
--zindex-alerts: 1060;
--zindex-tooltip: 1070;
--flarum-screen: none;
--screen-phone-max: 767.98px;
--screen-tablet: 768px;
--screen-tablet-max: 991.98px;
--screen-desktop: 992px;
--screen-desktop-max: 1099.98px;
--screen-desktop-hd: 1100px
}
