Voici les principaux breakpoints de bootstrap:
/* X-Small devices (portrait phones, less than 576px)
No media query for `xs` since this is the default in Bootstrap*/
/* sm - Small devices (landscape phones, 576px and up)*/
@media screen and (min-width: 576px) { }
/* md - Medium devices (tablets, 768px and up) */
@media screen and (min-width: 768px) { }
/* lg - Large devices (desktops, 992px and up) */
@media screen and (min-width: 992px) { }
/* xl - X-Large devices (large desktops, 1200px and up)*/
@media screen and (min-width: 1200px) { }
/* xxl - XX-Large devices (larger desktops, 1400px and up)*/
@media screen and (min-width: 1400px) { }