my.kv

<CreateAccountWindow>:
    name: "create"
    username: username
    email: email
    password: password

    FloatLayout:
        cols:1

        FloatLayout:
            size: root.width, root.height/2

            Label:
                text: "Create an Account"
                size_hint: 0.8, 0.2
                pos_hint: {"x":0.1, "top":1}
                font_size: (root.width**2 + root.height**2) / 14**4

            Label:
                size_hint: 0.5,0.12
                pos_hint: {"x":0, "top":0.8}
                text: "Username: "
                font_size: (root.width**2 + root.height**2) / 14**4

            TextInput:
                pos_hint: {"x":0.5, "top":0.8}
                size_hint: 0.4, 0.12
                id: username
                multiline: False
                font_size: (root.width**2 + root.height**2) / 14**4

            Label:
                size_hint: 0.5,0.12
                pos_hint: {"x":0, "top":0.8-0.13}
                text: "Email: "
                font_size: (root.width**2 + root.height**2) / 14**4

            TextInput:
                pos_hint: {"x":0.5, "top":0.8-0.13}
                size_hint: 0.4, 0.12
                id: email
                multiline: False
                font_size: (root.width**2 + root.height**2) / 14**4

            Label:
                size_hint: 0.5,0.12
                pos_hint: {"x":0, "top":0.8-0.13*2}
                text: "Password: "
                font_size: (root.width**2 + root.height**2) / 14**4

            TextInput:
                pos_hint: {"x":0.5, "top":0.8-0.13*2}
                size_hint: 0.4, 0.12
                id: password
                multiline: False
                password: True
                font_size: (root.width**2 + root.height**2) / 14**4

        Button:
            pos_hint:{"x":0.3,"y":0.25}
            size_hint: 0.4, 0.1
            font_size: (root.width**2 + root.height**2) / 17**4
            text: "Already have an Account? Log In"
            on_release:
                root.manager.transition.direction = "left"
                root.login()

        Button:
            pos_hint:{"x":0.2,"y":0.05}
            size_hint: 0.6, 0.15
            text: "Submit"
            font_size: (root.width**2 + root.height**2) / 14**4
            on_release:
                root.manager.transition.direction = "left"
                root.submit()

<LoginWindow>:
    name: "login"
    username: username
    password: password

    FloatLayout:

        Label:
            text:"Username: "
            font_size: (root.width**2 + root.height**2) / 13**4
            pos_hint: {"x":0.1, "top":0.9}
            size_hint: 0.35, 0.15

        TextInput:
            id: username
            font_size: (root.width**2 + root.height**2) / 13**4
            multiline: False
            pos_hint: {"x": 0.45 , "top":0.9}
            size_hint: 0.4, 0.15

        Label:
            text:"Password: "
            font_size: (root.width**2 + root.height**2) / 13**4
            pos_hint: {"x":0.1, "top":0.7}
            size_hint: 0.35, 0.15

        TextInput:
            id: password
            font_size: (root.width**2 + root.height**2) / 13**4
            multiline: False
            password: True
            pos_hint: {"x": 0.45, "top":0.7}
            size_hint: 0.4, 0.15

        Button:
            pos_hint:{"x":0.2,"y":0.05}
            size_hint: 0.6, 0.2
            font_size: (root.width**2 + root.height**2) / 13**4
            text: "Login"
            on_release:
                root.manager.transition.direction = "up"
                root.loginBtn()

        Button:
            pos_hint:{"x":0.3,"y":0.3}
            size_hint: 0.4, 0.1
            font_size: (root.width**2 + root.height**2) / 17**4
            text: "Don't have an Account? Create One"
            on_release:
                root.manager.transition.direction = "right"
                root.createBtn()

<HomeWindow>:
    name: "home"

    FloatLayout:
        Button:
            pos_hint:{"x": 0.2, "top":0.9}
            size_hint:0.6,0.2
            text: "Listen to Lecture"
            on_release:
                root.LectureLength.Set()
                root.RecordLectureBtn()
                root.manager.transition.direction = "right"

        Button:
            pos_hint:{"x": 0.2, "top":0.7}
            size_hint:0.6,0.2
            text: "Previous Lectures"
            on_release:
                root.manager.transition.direction = "left"
                app.root.current = "pl"

        Button:
            pos_hint:{"x": 0.2, "top":0.5}
            size_hint:0.6,0.2
            text: "Settings"
            on_release:
                app.root.current = "settings"
                root.manager.transition.direction = "up"

        Button:
            pos_hint:{"x": 0.2, "top":0.3}
            size_hint:0.6,0.2
            text: "Log Out"
            on_release:
                app.root.current = "login"
                root.manager.transition.direction = "down"

<PrevLecWindow>:
    name: "pl"
    scr: scroll
    layout: grid

    Button:
        pos_hint:{"left": 0.2, "top":1}
        size_hint:0.2,0.1
        text: "Back"
        on_release:
            app.root.current = "home"
            root.manager.transition.direction = "right"

    ScrollView:
        id: scroll
        text: 'self.id'
        do_scroll_x: False
        do_scroll_y: True
        size_hint_x: 1
        size_hint_y: 0.9
        size_x: root.width
        size_y: root.height
        GridLayout:
            id: grid
            text: 'self.id'
            cols: 1
            spacing: 20
            size_hint_y: None

<SettingsWindow>:
    name: "settings"

    FloatLayout:

        Label:
            text:"Font Size: "
            font_size: (root.width**2 + root.height**2) / 13**4
            pos_hint: {"x":0.1, "top":0.85}
            size_hint: 0.35, 0.15

        Spinner:
            id: font Size
            size_hint: 0.4, 0.15
            size: 100, 44
            pos_hint: {"x": .45, "top":0.85}
            text: 'small'
            values: 'small', 'medium', 'large'
            on_value:

        Label:
            text:"Font Type: "
            font_size: (root.width**2 + root.height**2) / 13**4
            pos_hint: {"x":0.1, "top":0.65}
            size_hint: 0.35, 0.15

        Spinner:
            id: font Type
            size_hint: 0.4, 0.15
            size: 100, 44
            pos_hint: {"x": .45, "top":0.65}
            text: 'Ariel'
            values: 'Ariel', 'Times', 'Comic Sans'
            on_value:

        Label:
            text:"Font Color: "
            font_size: (root.width**2 + root.height**2) / 13**4
            pos_hint: {"x":0.1, "top":0.45}
            size_hint: 0.35, 0.15

        Spinner:
            id: font Color
            size_hint: 0.4, 0.15
            size: 100, 44
            pos_hint: {"x": .45, "top":0.45}
            text: 'White'
            values: 'White', 'Black', 'Red'
            on_value:

        Label:
            text:"Background: "
            font_size: (root.width**2 + root.height**2) / 13**4
            pos_hint: {"x":0.1, "top":0.25}
            size_hint: 0.35, 0.15

        Spinner:
            id: BColor
            size_hint: 0.4, 0.15
            size: 100, 44
            pos_hint: {"x": .45, "top":0.25}
            text: 'Black'
            values: 'Black', 'White', 'Red'
            on_value:

        Button:
            rgba: 1, 0, 0, 1
            pos_hint:{"left": 0.2, "top":1}
            size_hint:0.2,0.1
            text: "Back"
            on_release:
                app.root.current = "home"
                root.manager.transition.direction = "down"