以下为优化后的难度系统：
| 优化后难度 | 对应KaTex数学公式 |
|---|---|
| \(\color{FE4C61}{{入门}}\) | \color{FE4C61}{{入门}} |
| \(\color{F39C11}{{普及-}}\) | \color{F39C11}{{普及-}} |
| \(\color{FFC116}{{普及}}\) | \color{FFC116}{{普及}} |
| \(\color{FFD700}{{普及+}}\) | \color{FFD700}{{普及+}} |
| \(\color{7FF000}{{提高-}}\) | \color{7FF0700}{{提高-}} |
| \(\color{52C41A}{{提高}}\) | \color{52C41A}{{提高}} |
| \(\color{228B22}{{提高+}}\) | \color{228B22}{{提高+}} |
| \(\color{3498DB}{{省选-}}\) | \color{3498DB}{{省选-}} |
| \(\color{4169E1}{{省选/NOI-}}\) | \color{4169E1}{{省选/NOI-}} |
| \(\color{9D3DCF}{{省选+/NOI}}\) | \color{9D3DCF}{{省选+/NOI}} |
| \(\color{0E1D69}{{NOI+/CTSC}}\) | \color{0E1D69}{{NOI+/CTSC}} |