bootstrap_responsive_text_align.css

.text-xs-left { text-align: left; }
.text-xs-right { text-align: right; }
.text-xs-center { text-align: center; }
.text-xs-justify { text-align: justify; }

@media (min-width: 768px) {
    .text-sm-left { text-align: left; }
    .text-sm-right { text-align: right; }
    .text-sm-center { text-align: center; }
    .text-sm-justify { text-align: justify; }
}

@media (min-width: 992px) {
    .text-md-left { text-align: left; }
    .text-md-right { text-align: right; }
    .text-md-center { text-align: center; }
    .text-md-justify { text-align: justify; }
}

@media (min-width: 1200px) {
    .text-lg-left { text-align: left; }
    .text-lg-right { text-align: right; }
    .text-lg-center { text-align: center; }
    .text-lg-justify { text-align: justify; }
}