+# list of regexes for known sans serif fonts
+my %sansFonts = (
+ "a" => qr/^(arial|andika|angostura|anonymous|arab|aroania|arimo|asap)/i,
+ "b" => qr/^(baekmuk|bebas|berenika|beteckna|beuron|blue)/i,
+ "c" => qr/^(cabin|caliban|cantarell|carbon|carlito|chandas|chivo|cmu bright|comfortaa|comic|cortoba|cousine|cuprum|cwtex(hei|yen)|cyklop|cypro)/i,
+ "d" => qr/^(d2coding|dimnah|dosis|dyuthi)/i,
+ "e" => qr/^(electron|engebrechtre)/i,
+ "f" => qr/^(fandolhei|fetamont|fira|font awesome 5|forgotten)/i,
+ "g" => qr/^(gardiner|garuda|gfs ?neo|gillius|granada|graph|guanine|gunplay)/i,
+ "h" => qr/^(hack|hani|haramain|harano|harmattan|hor\b)/i,
+ "i" => qr/^(ibm plex|ikarius|inconsolata|induni.?h|iwona)/i,
+ "j" => qr/^(jara|jura)/i,
+ "k" => qr/^(kalimati|kanji|karla|kayrawan|kenyan|keraleeyam|khalid|khmer [or]|kiloji|klaudia|komatu|kurier)/i,
+ "l" => qr/^(laksaman|larabie|lato|league|lexend|lexigulim|libel|liberation|libre franklin|libris|linux biolinum|lobster|logix|lohit|loma)/i,
+ "m" => qr/^(m\+ |manchu|manjari|marcellus|mashq|meera|metal|migmix|migu|mikachan|mintspirit|mona|monlam|mono(fonto|id|isome|noki)|montserrat|motoyal|mukti|musica)/i,
+ "n" => qr/^(nachlieli|nada|nafees|nagham|nanum(barunpen|square)|nice)/i,
+ "o" => qr/^(ocr|okolaks|opendyslexic|ostorah|ouhud|over|oxygen)/i,
+ "p" => qr/^(padauk|padmaa|pagul|paktype|pakenham|palladio|petra|phetsarath|play\b|poiret|port\b|primer\b|prociono|pt\b|purisa)/i,
+ "q" => qr/^(qt(ancient|helvet|avanti|eratype|eurotype|floraline|florencia|frank|fritz|future|greece|howard|letter|optimum|pandora)|quercus)/i,
+ "r" => qr/^(rachana|radio\b|raleway|ricty|roboto|rosario)/i,
+ "s" => qr/^(salem|samanata|sawasdee|shado|sharja|simple|sophia|soul|source|switzera)/i,
+ "t" => qr/^(tarablus|teen|texgyre(adventor|heros)|tiresias|trebuchet|tscu|tuffy)/i,
+ "u" => qr/^(ubuntu|ukij (bom|chechek|cjk|diwani|ekran|elipbe|inchike|jelliy|kufi|qara|qolyazma|teng|title|tor)|umpush|un ?(dinaru|jamo|graphic|taza|vada|yetgul)|uni(kurd|space|versalis)|uroob|urw ?classico)/i,
+ "v" => qr/^(veranda|vn ?urwclassico)/i,
+ "w" => qr/^(waree)/i,
+ "y" => qr/^(yanone)/i,
+ "z" => qr/^(zekton|zero)/i,
+);