constexpr int count = 5;
static float times[count] = zero;

for(int i = 0; i < count; i++)
{
    s_v2 size = v2(200, 64);
    size.x += times[i] * 20;
    s_v2 pos = v2(c_world_size.x - size.x, 400 + i * 100);
    pos.x -= times[i] * 10;
    if(mouse_collides_rect_tl(input->mouse, pos, size))
    {
        times[i] = clamp(times[i] + delta * 10, 0.0f, 1.0f);
    }
    else
    {
        times[i] = clamp(times[i] - delta * 2, 0.0f, 1.0f);
    }
    s_v4 col = lerp_v4(WHITE, GREEN, times[i]);
    ui_rect(pos, size, col);
}