diff --git a/src/AcDream.App/Rendering/Shaders/mesh.frag b/src/AcDream.App/Rendering/Shaders/mesh.frag
index 28503bb..42d2d96 100644
--- a/src/AcDream.App/Rendering/Shaders/mesh.frag
+++ b/src/AcDream.App/Rendering/Shaders/mesh.frag
@@ -9,9 +9,13 @@ uniform sampler2D uDiffuse;
 // gives scenery and building faces enough differentiation to read as 3D instead
 // of looking like paper cutouts. Hardcoded for now; a later phase can route
 // light parameters through uniforms driven by the game's time-of-day.
-const vec3 SUN_DIR = normalize(vec3(0.4, 0.3, 0.8));
-const float AMBIENT = 0.4;
-const float DIFFUSE = 0.6;
+// Sun direction tuned after Phase 3a verification: (0.4,0.3,0.8) was too
+// vertical — roofs and ground both landed near peak brightness and only
+// walls dropped, so the contrast was hard to read through textures. More
+// oblique + lower ambient + higher diffuse = contrast ratio ~3.3x.
+const vec3 SUN_DIR = normalize(vec3(0.5, 0.4, 0.6));
+const float AMBIENT = 0.25;
+const float DIFFUSE = 0.75;
 
 void main() {
     vec4 sampled = texture(uDiffuse, vTex);
diff --git a/src/AcDream.App/Rendering/Shaders/terrain.frag b/src/AcDream.App/Rendering/Shaders/terrain.frag
index f3ebbe4..76a8db0 100644
--- a/src/AcDream.App/Rendering/Shaders/terrain.frag
+++ b/src/AcDream.App/Rendering/Shaders/terrain.frag
@@ -6,14 +6,12 @@ out vec4 fragColor;
 
 uniform sampler2DArray uAtlas;
 
-// Phase 3a: shared lighting model with mesh.frag. Terrain normals are currently
-// flat UnitZ (Phase 2b set this when building LandblockMesh vertices) so every
-// terrain fragment gets the same ndotl contribution — terrain will look a bit
-// flatter than hill-shaded terrain, which is a Phase 3b concern (compute
-// per-vertex normals from the 9x9 heightmap to get relief lighting).
-const vec3 SUN_DIR = normalize(vec3(0.4, 0.3, 0.8));
-const float AMBIENT = 0.4;
-const float DIFFUSE = 0.6;
+// Shared lighting model with mesh.frag — must stay in sync. Phase 3b gave
+// terrain real per-vertex normals via central differences on the heightmap,
+// so hills catch and shade the sun just like static meshes do.
+const vec3 SUN_DIR = normalize(vec3(0.5, 0.4, 0.6));
+const float AMBIENT = 0.25;
+const float DIFFUSE = 0.75;
 
 void main() {
     vec4 sampled = texture(uAtlas, vec3(vTex, float(vLayer)));