img {
            border: none !important;
        }
        .gradient-bg {
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
        }
        .citation-box {
            border-left: 4px solid #3b82f6;
            background-color: #eff6ff;
        }
        .misconception-box {
            border-left: 4px solid #ef4444;
            background-color: #fef2f2;
        }
        .checklist-box {
            border-left: 4px solid #10b981;
            background-color: #f0fdf4;
        }
        .question-box {
            border: 2px dashed #8b5cf6;
            background-color: #faf5ff;
        }
       .aspect-w-16 {
            position: relative;
            padding-bottom: 56.25%; /* 16:9 aspect ratio */
        }
       .aspect-w-16 > iframe {
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
        }