start.kv

MDScreen:
    name:"start"
    MDFloatLayout:
        md_bg_color : 1,1,1,1
        Image:
            source:"background.png"
            size:1,1

        MDLabel:
            text:"Math\nSolver"
            font_name:"LuckiestGuy"
            font_size:"55sp"
            halign:"center"
            pos_hint:{"center_x":.5, "center_y":.7}
            color:1,1,1,1
            line_height:1.1
        Button:
            text:"Start"
            font_name:"LuckiestGuy"
            font_size:"40sp"
            size_hint: .55, .12
            pos_hint:{"center_x":.5, "center_y":.15}
            background_color:1,1,1,0
            on_release:
                root.manager.current="select_sign"
            canvas.before:
                Color:
                    rgb:rgba(251,187,30,255)
                RoundedRectangle:
                    size: self.size
                    pos: self.x,self.y+5
                    radius:[10]