i think this is right for flex
display:-ms-flexbox; //for ie older version
display:-webkit-flex; //for chrome older version,firefox older version,safari
display:-webkit-box; //for android ucbrowsers forever,i think you gonna try this line
display:flex; //for all new versions browsers like chrome 66 and above firefox 46 and above ie11 and above eventhough safari , opera and some more newversion browsers can support this line
you can go for this line in ucbrowsers in mobile or pc => display:-webkit-box;
if you want inlie-flex try this and it's works display:-webkit-inline-box;