/* Default: hide all language blocks */
.en-only, .ja-only, .vi-only { display: none; }

/* EN active */
html[lang*="en"] .en-only { display: block; }

/* JA active */
html[lang*="ja"] .ja-only { display: block; }

/* VI active */
html[lang*="vi"] .vi-only { display: block; }