Bách khoa toàn thư mở Wikipedia
/* .main-header */.main-header { display: flex; flex-flow: wrap column; font-size: 1rem; background-image: url(//upload.wikimedia.org/wikipedia/commons/9/9d/Set_Knowledge_Free_mural_illustration.svg); background-size: cover; background-position: right; background-repeat: no-repeat;}/* .main-header__left */.main-header__left,.main-header__right { flex: auto; display: flex; flex-flow: wrap column; justify-content: center; align-content: center; background-color: rgba(255, 255, 255, 0.9);}.main-header__left { padding-top: 1.5em;}.main-header__title { margin: 0; padding: 0 1em; border-bottom: 0; letter-spacing: 0.1em; text-transform: uppercase; font-size: 1.4em;}.main-header__slogan { padding-top: 0.5em;}/* .main-header__right */.main-header__right { padding-bottom: 0.5em; font-size: 0.875em;}.main-header__count { padding: 1em 0 0.75em;}.main-header__shortcut { display: flex; flex-wrap: wrap; justify-content: center;}/* .main-header__bottom */.main-header__bottom { display: none;}.main-header__bottom a { white-space: nowrap;}/* responsive */@media (max-width: 575px) { /* .main-header__right */ .main-header__shortcut li:nth-child(1), .main-header__shortcut li:nth-child(3) { display: none; }}@media (min-width: 576px) { /* .main-header */ .main-header { background-color: #f8f9fa; border: 1px solid #e0e0e0; box-shadow: 0px 2px 3px #eee; } /* .main-header__left */ .main-header__title { font-size: 1.55em; } /* .main-header__right */ .main-header__right { padding: 0 1em 1.5em; } /* .main-header__bottom */ .main-header__bottom { display: flex; flex-flow: wrap column; justify-content: center; align-content: center; width: 100%; background-color: #fff; border-top: 1px solid #e0e0e0; font-size: 0.875em; } .main-header__article-link, .main-header__help-link { padding: 0.75em 2em; text-align: center; } .main-header__article-link { margin-bottom: -0.75em; }}@media (min-width: 1200px) { /* .main-header */ .main-header { flex-direction: row; } /* .main-header__left */ .main-header__left { padding: 1.5em 0; } /* .main-header__right */ .main-header__right { padding-bottom: 0; } /* .main-header__bottom */ .main-header__bottom { flex-direction: row; } .main-header__article-link, .main-header__help-link { flex: 1; } .main-header__article-link { text-align: right; margin-bottom: 0; } .main-header__help-link { text-align: left; }}