body{ background:#f8f9fa; }
.lesson-header{
    background:linear-gradient(90deg,#28a745,#20c997);
    color:white;
    padding:45px 20px;
    text-align:center;
    margin-bottom:40px;
}
.section-title{ margin-top:40px; margin-bottom:20px; font-weight:bold; }
.table th{ background:#f0f0f0; }
.example{ margin-bottom:12px; }
.translation{ color:#777; font-size:.9rem; margin-left:20px; }
.resume{ background:#e8f5e9; border-left:5px solid #28a745; padding:20px; border-radius:5px; }
footer{ background:#212529; color:white; padding:40px 0; margin-top:60px; }