@property --menuColor { syntax: ''; inherits: true; initial-value: #DDD; } @property --activeTriggerColor { syntax: ''; inherits: true; initial-value: #DDD; } :root{ --activeTriggerColor : var(--activeTriggerColor); } .menu-list { contain : content; position : fixed; top : anchor(bottom); left : anchor(left); position-try: flip-inline flip-block; color: inherit; // [popover] gets a `canvastext` color value from useragent. background: var(--menuColor); li > .menu-list { margin: 0 0px; top : anchor(top); left : anchor(right); position-try: flip-inline; } } .menu-wrapper:has(:popover-open) > button { // if menu is open... background-color: var(--activeTriggerColor, hsl(from var(--menuColor) h s calc(l * .85))); // tint menu triggers based on menu color }