         display: none;
        }

        .presentation-controls {
            position: fixed;
            bottom: 30px;
            left: 50%;
            transform: translateX(-50%);
            display: flex;
            gap: 20px;
            align-items: center;
            background: rgba(0,0,0,0.7);
            padding: 15px 25px;
            border-radius: 50px;
            backdrop-filter: blur(10px);
            border: 1px solid rgba(255,255,255,0.2);
        }

        .control-btn {
        