The chat log content area is rendered as a child window, so leaving
ChildBg opaque kept the inner pane fully solid even when the slider
was dragged down — defeating the point during combat where the user
wants to see the game behind the chat. Mix the same alpha byte into
ChildBg now. FrameBg and PopupBg are deliberately left opaque so
text inputs, dropdowns, tooltips and modals stay readable on top.
JonKazama-Hellion
737ec6b868