lighting fsh which doesn't work (4)

#version 330 core

uniform vec3 viewPos;
uniform vec3 lightPos;
uniform float ambientStrength;

in vec3 fragPos;
in vec3 interpolatedNormal;

out vec4 fragColor;

const float lightStrength = 0.1;
const float specularStrength = 0.5;
const float gamma = 2.2;
const vec3 lightColor = vec3(1, 1, 1);
const vec3 objectColor = vec3(137.0/255.0, 183.0/255.0, 255.0/255.0);

// Code adpated from learnopengl.com
void main() {
    vec3 ambient = ambientStrength * lightColor;

    vec3 norm = normalize(interpolatedNormal);
    vec3 lightDir = normalize(lightPos - fragPos);
    float diff = max(dot(norm, lightDir), 0.0);
    vec3 diffuse = diff * lightColor;

    vec3 viewDir = normalize(viewPos - fragPos);
    vec3 reflectDir = reflect(-lightDir, norm);
    float spec = pow(max(dot(viewDir, reflectDir), 0.0), 32);
    vec3 specular = specularStrength * spec * lightColor;

    vec3 color = (ambient + diffuse + specular) * objectColor;
    vec3 corrected = pow(color, vec3(1.0 / gamma));
    fragColor = vec4(corrected, 1.0);
}