--// SETTINGS
local WALK_SPEED = 7
local SPRINT_SPEED = 28
local RUN_ANIM_SPEED = 3

--// REFERENCES
local player = game.Players.LocalPlayer

--// GUI SETUP
local gui = Instance.new("ScreenGui")
gui.Name = "SprintGui"
gui.ResetOnSpawn = false
gui.Parent = player:WaitForChild("PlayerGui")

local button = Instance.new("TextButton")
button.Size = UDim2.new(0, 120, 0, 120)
button.Position = UDim2.new(1, -140, 1, -180)
button.BackgroundColor3 = Color3.fromRGB(30, 30, 30)
button.BackgroundTransparency = 0.2
button.TextColor3 = Color3.new(1, 1, 1)
button.TextScaled = true
button.Text = "SPRINT"
button.Parent = gui

local corner = Instance.new("UICorner", button)
corner.CornerRadius = UDim.new(1, 0)

--// CHARACTER SETUP
local sprinting = false
local humanoid

local function updateAnimationSpeed()
    if not humanoid then return end

    for _, track in pairs(humanoid:GetPlayingAnimationTracks()) do
        if track.Name:lower():find("run") then
            track:AdjustSpeed(sprinting and RUN_ANIM_SPEED or 1)
        end
    end
end

local function applySpeed()
    if humanoid then
        humanoid.WalkSpeed = sprinting and SPRINT_SPEED or WALK_SPEED
        updateAnimationSpeed()
    end
end

local function setupCharacter(char)
    humanoid = char:WaitForChild("Humanoid")
    sprinting = false

    -- whenever a new animation plays, update it if sprinting
    humanoid.AnimationPlayed:Connect(function(track)
        if track.Name:lower():find("run") then
            track:AdjustSpeed(sprinting and RUN_ANIM_SPEED or 1)
        end
    end)

    applySpeed()
end

-- initial + respawn
if player.Character then
    setupCharacter(player.Character)
end
player.CharacterAdded:Connect(setupCharacter)

--// BUTTON LOGIC
button.MouseButton1Click:Connect(function()
    sprinting = not sprinting
    button.Text = sprinting and "SPRINT: ON" or "SPRINT"
    applySpeed()
end)