rewrite homepage

i found out that

MATHEMATICAL DOUBLE-STRUCK
U+1D543: 𝕃
U+1D544: 𝕄
U+1D545: Unassigned
U+1D546: 𝕆
U+1D547: Unassigned

Letterlike Symbols
U+2115: ℕ
U+2116: №
U+2117: ℗
U+2118: ℘
U+2119: ℙ
U+211A: ℚ

so even if i use the same font-family, ℕ might looks a bit different from others

therefore i gotta use

{
    font-family: Cambria, Cochin, Georgia, Times, 'Times New Roman', serif;
}

i dont even know whether it works or not