.a { -webkit-column-break-inside: auto; break-inside: auto; -webkit-column-break-before: auto; break-before: auto; -webkit-column-break-after: auto; break-after: auto;}
.b { -webkit-column-break-inside: avoid; break-inside: avoid;}
.c { -webkit-column-break-inside: avoid; break-inside: avoid-column;}
.d { break-inside: avoid-page;}
.e { break-inside: avoid-region;}
.f { break-inside: region;}