#version 410 core
layout(location = 0) in vec3 aPos;
layout(location = 1) in vec2 aUV;     // -1..1 quad corner
layout(location = 2) in float aAlpha; // per-shadow strength (hover fade)
uniform mat4 uVP;
out vec2 vUV;
out float vAlpha;
void main() {
    vUV = aUV;
    vAlpha = aAlpha;
    gl_Position = uVP * vec4(aPos, 1.0);
}
