diff --git a/Cargo.toml b/Cargo.toml
index ae82260..0cb5735 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "gui"
 version = "0.1.0"
-edition = "2021"
+edition = "2024"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
diff --git a/src/base/mod.rs b/src/base/mod.rs
index 0577fac..7c01703 100644
--- a/src/base/mod.rs
+++ b/src/base/mod.rs
@@ -1,8 +1,8 @@
 use std::ops::Range;
 
 use crate::{
-    primitive::{Axis, Painter, RoundedRectData, UIRegion},
     UIColor, Widget, WidgetArrLike, WidgetFn, WidgetId, WidgetLike,
+    primitive::{Axis, Painter, RoundedRectData, UIRegion},
 };
 
 #[derive(Clone, Copy)]
@@ -56,13 +56,13 @@ impl Span {
     ) -> Self {
         let ratios = ratios.map(|r| r.to_f32());
         let total: f32 = ratios.iter().sum();
-        let mut start = 0.0;
+        let mut start = -1.0;
         Self {
             elements: elements
                 .into_iter()
                 .zip(ratios)
                 .map(|(e, r)| {
-                    let end = start + r / total;
+                    let end = start + (r / total) * 2.0;
                     let res = (start..end, e);
                     start = end;
                     res
diff --git a/src/render/primitive/color.rs b/src/render/primitive/color.rs
index 131c1ba..7be0934 100644
--- a/src/render/primitive/color.rs
+++ b/src/render/primitive/color.rs
@@ -30,6 +30,10 @@ impl<T: ColorNum> Color<T> {
     pub const fn rgb(r: T, g: T, b: T) -> Self {
         Self { r, g, b, a: T::MAX }
     }
+    pub fn alpha(mut self, a: T) -> Self {
+        self.a = a;
+        self
+    }
 }
 
 pub trait ColorNum {
diff --git a/src/render/primitive/format.rs b/src/render/primitive/format.rs
index a9578cb..e3a3e6d 100644
--- a/src/render/primitive/format.rs
+++ b/src/render/primitive/format.rs
@@ -1,7 +1,7 @@
-use crate::primitive::{point::point, Point};
+use crate::primitive::{Point, point::point};
 
 #[repr(C)]
-#[derive(Copy, Clone, bytemuck::Pod, bytemuck::Zeroable, Default)]
+#[derive(Debug, Copy, Clone, bytemuck::Pod, bytemuck::Zeroable, Default)]
 pub struct UIPos {
     pub anchor: Point,
     pub offset: Point,
@@ -16,7 +16,7 @@ impl UIPos {
     }
 
     pub const fn top_left() -> Self {
-        Self::anchor_offset(0.0, 0.0, 0.0, 0.0)
+        Self::anchor_offset(-1.0, -1.0, 0.0, 0.0)
     }
 
     pub const fn bottom_right() -> Self {
@@ -24,15 +24,14 @@ impl UIPos {
     }
 
     pub const fn within(&self, region: &UIRegion) -> UIPos {
-        let range = region.bot_right.anchor - region.top_left.anchor;
-        let region_offset = region
-            .top_left
-            .offset
-            .lerp(region.bot_right.offset, self.anchor);
-        UIPos {
-            anchor: region.top_left.anchor + self.anchor * range,
-            offset: self.offset + region_offset,
-        }
+        let lerp = self.anchor_01();
+        let anchor = region.top_left.anchor.lerp(region.bot_right.anchor, lerp);
+        let offset = self.offset + region.top_left.offset.lerp(region.bot_right.offset, lerp);
+        UIPos { anchor, offset }
+    }
+
+    pub const fn anchor_01(&self) -> Point {
+        (self.anchor + 1.0) / 2.0
     }
 
     pub fn axis_mut(&mut self, axis: Axis) -> UIPosAxisView<'_> {
diff --git a/src/render/primitive/point.rs b/src/render/primitive/point.rs
index a84244f..1385899 100644
--- a/src/render/primitive/point.rs
+++ b/src/render/primitive/point.rs
@@ -1,7 +1,7 @@
 use std::ops::*;
 
 #[repr(C)]
-#[derive(Clone, Copy, PartialEq, Default, bytemuck::Pod, bytemuck::Zeroable)]
+#[derive(Debug, Clone, Copy, PartialEq, Default, bytemuck::Pod, bytemuck::Zeroable)]
 pub struct Point {
     pub x: f32,
     pub y: f32,
diff --git a/src/render/shader.wgsl b/src/render/shader.wgsl
index b48ff5a..f3eb10e 100644
--- a/src/render/shader.wgsl
+++ b/src/render/shader.wgsl
@@ -42,8 +42,8 @@ fn vs_main(
 ) -> VertexOutput {
     var out: VertexOutput;
 
-    let top_left = in.top_left_anchor * window.dim + in.top_left_offset;
-    let bot_right = in.bottom_right_anchor * window.dim + in.bottom_right_offset;
+    let top_left = (in.top_left_anchor + 1.0) / 2.0 * window.dim + in.top_left_offset;
+    let bot_right = (in.bottom_right_anchor + 1.0) / 2.0 * window.dim + in.bottom_right_offset;
     let size = bot_right - top_left;
 
     var pos = top_left + vec2<f32>(
diff --git a/src/testing/mod.rs b/src/testing/mod.rs
index 2fbdd15..b6c871c 100644
--- a/src/testing/mod.rs
+++ b/src/testing/mod.rs
@@ -1,7 +1,7 @@
 use std::sync::Arc;
 
 use app::App;
-use gui::{primitive::Axis, RoundedRect, UIColor, WidgetArrUtil, WidgetUtil, UI};
+use gui::{RoundedRect, UI, UIColor, WidgetArrUtil, WidgetUtil, primitive::Axis};
 use render::Renderer;
 use winit::{event::WindowEvent, event_loop::ActiveEventLoop, window::Window};
 
@@ -50,6 +50,7 @@ impl Client {
                 .span(Axis::Y, [3, 1])
                 .pad(10),
         );
+        // let mut ui = ui.finish((blue, rect.color(UIColor::RED)).span(Axis::X, [1, 1]));
         ui.widgets.get_mut(&handle).unwrap().color = UIColor::MAGENTA;
         renderer.update(&ui);
         Self { renderer }