diff --git a/hammerspoon/modules/windows.lua b/hammerspoon/modules/windows.lua
index 0141167e..ee54f46b 100644
--- a/hammerspoon/modules/windows.lua
+++ b/hammerspoon/modules/windows.lua
@@ -1,2 +1,114 @@
 -- TODO: Window management library
 
+local window = {
+    direction = {
+        up = 1,
+        down = 2,
+        left = 4,
+        right = 8
+    },
+
+    move = function (x, y, w, h)
+    end,
+
+    slide = function (direction, amount)
+    end,
+
+    resizeIn = function (direction, amount)
+    end,
+
+    resizeOut = function (direction, amount)
+    end,
+}
+
+--
+local modes = {
+    position = hs.hotkey.modal.new('cmd-ctrl', 'up'),
+    resizeTL = hs.hotkey.modal.new('cmd-ctrl', 'left'),
+    resizeBR = hs.hotkey.modal.new('cmd-ctrl', 'right'),
+}
+local currentMode = nil
+
+-- Screen overlay
+local function initOverlay(width, height)
+    local f = hs.screen.primaryScreen():frame()
+    return hs.drawing.rectangle(hs.geometry(
+                                    (f.w / 2) - (width / 2),
+                                    (f.h / 2) - (height / 2),
+                                    width, height))
+        :setAlpha(0.65)
+        :setFillColor(hs.drawing.color.black)
+        :bringToFront()
+end
+local overlay = initOverlay(300, 400)
+
+--
+for key, modal in pairs(modes) do
+    modal:bind('', 'escape', function() modal:exit() end)
+
+    modal.entered = function(self)
+        for k, m in pairs(modes) do
+            if k ~= key then m:exit() end
+        end
+        currentMode = key
+        overlay:show()
+    end
+    modal.exited = function(self)
+        if currentMode == key then
+            currentMode = nil
+            overlay:hide()
+        end
+    end
+end
+
+local step = 10
+local bigstep = 100
+
+modes.position
+    :bind('cmd', 'up',      function() window.slide(window.direction.up,         true) end)
+    :bind('cmd', 'down',    function() window.slide(window.direction.down,       true) end)
+    :bind('cmd', 'left',    function() window.slide(window.direction.left,       true) end)
+    :bind('cmd', 'right',   function() window.slide(window.direction.right,      true) end)
+
+    :bind('shift', 'up',    function() window.slide(window.direction.up,         step) end)
+    :bind('shift', 'down',  function() window.slide(window.direction.down,       step) end)
+    :bind('shift', 'left',  function() window.slide(window.direction.left,       step) end)
+    :bind('shift', 'right', function() window.slide(window.direction.right,      step) end)
+
+    :bind('alt', 'up',      function() window.slide(window.direction.up,         bigstep) end)
+    :bind('alt', 'down',    function() window.slide(window.direction.down,       bigstep) end)
+    :bind('alt', 'left',    function() window.slide(window.direction.left,       bigstep) end)
+    :bind('alt', 'right',   function() window.slide(window.direction.right,      bigstep) end)
+
+modes.resizeTL
+    :bind('cmd', 'up',      function() window.resizeOut(window.direction.up,    true) end)
+    :bind('cmd', 'down',    function() window.resizeIn(window.direction.down,   true) end)
+    :bind('cmd', 'left',    function() window.resizeOut(window.direction.left,  true) end)
+    :bind('cmd', 'right',   function() window.resizeIn(window.direction.right,  true) end)
+
+    :bind('shift', 'up',    function() window.resizeOut(window.direction.up,    step) end)
+    :bind('shift', 'down',  function() window.resizeIn(window.direction.down,   step) end)
+    :bind('shift', 'left',  function() window.resizeOut(window.direction.left,  step) end)
+    :bind('shift', 'right', function() window.resizeIn(window.direction.right,  step) end)
+
+    :bind('alt', 'up',      function() window.resizeOut(window.direction.up,    bigstep) end)
+    :bind('alt', 'down',    function() window.resizeIn(window.direction.down,   bigstep) end)
+    :bind('alt', 'left',    function() window.resizeOut(window.direction.left,  bigstep) end)
+    :bind('alt', 'right',   function() window.resizeIn(window.direction.right,  bigstep) end)
+
+modes.resizeBR
+    :bind('cmd', 'up',      function() window.resizeIn(window.direction.up,     true) end)
+    :bind('cmd', 'down',    function() window.resizeOut(window.direction.down,  true) end)
+    :bind('cmd', 'left',    function() window.resizeIn(window.direction.left,   true) end)
+    :bind('cmd', 'right',   function() window.resizeOut(window.direction.right, true) end)
+
+    :bind('shift', 'up',    function() window.resizeIn(window.direction.up,     step) end)
+    :bind('shift', 'down',  function() window.resizeOut(window.direction.down,  step) end)
+    :bind('shift', 'left',  function() window.resizeIn(window.direction.left,   step) end)
+    :bind('shift', 'right', function() window.resizeOut(window.direction.right, step) end)
+
+    :bind('alt', 'up',      function() window.resizeIn(window.direction.up,     bigstep) end)
+    :bind('alt', 'down',    function() window.resizeOut(window.direction.down,  bigstep) end)
+    :bind('alt', 'left',    function() window.resizeIn(window.direction.left,   bigstep) end)
+    :bind('alt', 'right',   function() window.resizeOut(window.direction.right, bigstep) end)
+