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#0003}.lesson-list{padding-left:1rem}.lesson-item{padding:.5rem;cursor:pointer;border-radius:6px;transition:all .3s ease;margin-bottom:.3rem;border-left:3px solid transparent}.lesson-item:hover{background:#f8f9ff;border-left-color:#667eea}.lesson-item.active{background:linear-gradient(135deg,#667eea,#764ba2);color:#fff;border-left-color:#fff}.lesson-number{font-weight:600;color:#667eea;margin-right:.5rem}.lesson-item.active .lesson-number{color:#fff}.lesson-duration{font-size:.9rem;opacity:.7;float:right}.main-content{background:#fff;border-radius:12px;box-shadow:0 4px 20px #0000001a;overflow:hidden}.video-container{position:relative;width:100%;height:0;padding-bottom:56.25%;background:#000}.video-container 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p{text-align:center;color:#666;margin-bottom:30px}.form-group{margin-bottom:20px}.form-group label{display:block;margin-bottom:5px;color:#333;font-weight:500}.form-group input{width:100%;padding:12px;border:2px solid #ddd;border-radius:5px;font-size:16px;transition:border-color .3s;box-sizing:border-box}.form-group input:focus{outline:none;border-color:#667eea}.form-group input:disabled{background-color:#f5f5f5;cursor:not-allowed}button[type=submit]{width:100%;padding:12px;background:linear-gradient(135deg,#667eea,#764ba2);color:#fff;border:none;border-radius:5px;font-size:16px;font-weight:500;cursor:pointer;transition:transform .2s}button[type=submit]:hover:not(:disabled){transform:translateY(-2px)}button[type=submit]:disabled{opacity:.7;cursor:not-allowed;transform:none}.error-message{background-color:#fee;color:#c33;padding:10px;border-radius:5px;margin-bottom:20px;text-align:center;border:1px solid #fcc}.demo-credentials{margin-top:30px;padding-top:20px;border-top:1px solid 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