I offer online mathematics lessons for grades 7–12 and, depending on the curriculum, also grade 13. The focus is on building a solid understanding of fundamentals and developing systematic problem-solving skills: we clarify core concepts, practice clear and structured solution methods, and build strategies that work even for challenging tasks. In addition, I offer Olympiad training (non-standard problems, logic, proof techniques) as well as a university preparatory course as a structured introduction to calculus (analysis) and linear algebra.