html, body { height: 100%; font-size: 16px; font-weight: 400; }
ul, li { list-style: none; margin: 0; padding: 0; }
.fullImg img { width: 100%; margin: 4px 0; }
.halfImg a { width: 50%; margin: 4px 0; padding: 4px; margin-left: -4px; margin-right: -4px; }
.table-form>tbody>tr>th, .table-form>tbody>tr>td { border-bottom: 0; }
.table td, .table th { font-weight: 400; }
.inputItem span { padding-top: 5px; text-align: right; padding-right: 6px; }
.w-half { width: 50%; }
.w-half2 { width: 25%; }
.w-140px { width: 140px; }
.btnItem { margin: 20px; }
.btnItem .btn { padding: 8px 26px; font-size: 14px; }
.marginBottom20 { margin-bottom: 20px; }
.uploadVideo .btn { border-radius: 18px; }
.nav_teacher .active { position: relative; }
.nav_teacher .active:before { content: ""; width: 0; height: 0; position: absolute; left: 50%; bottom: 0; margin-left: -5px; border-right: 10px solid transparent; border-bottom: 10px solid #FFFFFF; border-left: 10px solid transparent; }