If you have a child theme, you can add this to the end of your child theme’s style.css file. Otherwise, you can use a CSS plugin like Jetpack or Custom CSS Manager.
/* Flexbox container */
#masthead {
display: -webkit-box; /* OLD - iOS 6-, Safari 3.1-6 */
display: -moz-box; /* OLD - Firefox 19- (buggy but mostly works) */
display: -ms-flexbox; /* TWEENER - IE 10 */
display: -webkit-flex; /* NEW - Chrome */
display: flex; /* NEW, Spec - Opera 12.1, Firefox 20+ */
-webkit-box-orient: vertical;
-ms-flex-direction: column;
-webkit-flex-direction: column;
flex-direction: column;
}
.header-image {
-webkit-box-ordinal-group: 1; /* OLD - iOS 6-, Safari 3.1-6 */
-moz-box-ordinal-group: 1; /* OLD - Firefox 19- */
-ms-flex-order: 1; /* TWEENER - IE 10 */
-webkit-order: 1; /* NEW - Chrome */
order: 1; /* NEW, Spec - Opera 12.1, Firefox 20+ */
}
.site-header-main {
-webkit-box-ordinal-group: 2; /* OLD - iOS 6-, Safari 3.1-6 */
-moz-box-ordinal-group: 2; /* OLD - Firefox 19- */
-ms-flex-order: 2; /* TWEENER - IE 10 */
-webkit-order: 2; /* NEW - Chrome */
order: 2; /* NEW, Spec - Opera 12.1, Firefox 20+ */
}