【界面UI】多级弹窗：确认框叠确认框的层级管理实现

local modalStack = {}
local function pushModal(widgetId)
    local layer = #modalStack + 1
    table.insert(modalStack, { id = widgetId, layer = layer })
    GUI:Win_Open(widgetId)
    return layer
end
local function popModal()
    local top = table.remove(modalStack)
    if top then
        GUI:Win_Close(top.id)
        return top.id
    end
    return nil
end

local function addMask(layer, parent)
    local alpha = 90 - layer * 20
    if alpha < 30 then alpha = 30 end
    local mask = GUI:Text_Create(parent, "Mask" .. layer, 0, 0, 12,
        string.format("#%02X%02X%02X", alpha, alpha, alpha), "")
end