$fn = 64;

// --- Parameters ---
cup_height = 40;        // Total height of the cup
outer_radius = 25;      // Outer radius of the cup (50mm diameter)
wall_thickness = 2.5;   // Thickness of the side walls
base_thickness = 3.0;   // Thickness of the bottom center

// --- Calculated Variables ---
inner_radius = outer_radius - wall_thickness;
scoop_center_z = base_thickness + inner_radius;

// --- Geometry ---
difference() {
    // Outer shell
    cylinder(h = cup_height, r = outer_radius);

    // Inner void
    union() {
        // Rounded interior bottom for easy scooping
        translate([0, 0, scoop_center_z])
            sphere(r = inner_radius);

        // Straight interior walls above the curve
        // Over-extended height ensures a clean manifold cut through the top
        translate([0, 0, scoop_center_z])
            cylinder(h = cup_height, r = inner_radius);
    }
}