.symbol-keyboard { display: grid; grid-template-columns: repeat(auto-fit, minmax(60px, 1fr)); gap: 8px; margin-bottom: 1rem; }
        .symbol-btn { padding: 10px; border: 1px solid #ddd; border-radius: 6px; background-color: white; text-align: center; cursor: pointer; transition: all 0.3s; font-size: 1.2rem; font-weight: 600; }
        .symbol-btn:hover { background-color: var(--light-gray); border-color: var(--primary-color); }
        .symbol-btn.operator { background-color: rgba(52,152,219,0.1); color: var(--primary-color); }
        .symbol-btn.parenthesis { background-color: rgba(46,204,113,0.1); color: #2ecc71; }
        .symbol-btn.not { background-color: rgba(155,89,182,0.1); color: #9b59b6; }
        .truth-table-container { overflow-x: auto; margin-top: 1.5rem; }
        .truth-table { width: 100%; border-collapse: collapse; min-width: 600px; }
        .truth-table th, .truth-table td { padding: 0.75rem; text-align: center; border: 1px solid #ddd; }
        .truth-table th { background-color: rgba(52,152,219,0.1); color: var(--primary-color); }
        .truth-table .true { background-color: rgba(46,204,113,0.1); color: var(--success-color); font-weight: 600; }
        .truth-table .false { background-color: rgba(231,76,60,0.1); color: var(--danger-color); font-weight: 600; }
        .karnaugh-map { margin: 1.5rem 0; border-collapse: collapse; margin-left: auto; margin-right: auto; }
        .karnaugh-map th, .karnaugh-map td { border: 1px solid #ddd; padding: 0.75rem; text-align: center; min-width: 60px; }
        .karnaugh-map th { background-color: rgba(52,152,219,0.1); }
        .karnaugh-map .cell-highlight { background-color: rgba(46,204,113,0.2); font-weight: 600; }
        .step-card { background-color: white; border-radius: 8px; border: 1px solid #ddd; padding: 1.25rem; margin-bottom: 1rem; }
        .math-explanation { background-color: rgba(52,152,219,0.05); border-left: 4px solid var(--primary-color); padding: 1.5rem; border-radius: 0 8px 8px 0; margin: 1.5rem 0; }
        .error-box { background-color: #f8d7da; border-left: 4px solid #e74c3c; padding: 1rem; border-radius: 4px; margin-top: 1rem; color: #721c24; }