.mode-selector {
            display: flex;
            gap: 10px;
            margin-bottom: 30px;
            flex-wrap: wrap;
        }

        .mode-btn {
            padding: 12px 24px;
            border: none;
            border-radius: 25px;
            background: #f0f0f0;
            color: #333;
            cursor: pointer;
            transition: all 0.3s ease;
            font-size: 14px;
        }

        .mode-btn.active {
            background: var(--primary-color);
            color: white;
        }

        .mode-btn:hover {
            transform: translateY(-2px);
            box-shadow: 0 5px 15px rgba(0,0,0,0.2);
        }

        .calculator-section {
            display: none;
        }

        .calculator-section.active {
            display: block;
        }

        .info-box {
            background: #e3f2fd;
            border: 1px solid #2196f3;
            border-radius: 10px;
            padding: 15px;
            margin-bottom: 20px;
        }

        .info-box h4 {
            color: #1976d2;
            margin-bottom: 10px;
        }

        .info-box p {
            color: #424242;
            line-height: 1.6;
        }

        .formula-box {
            background: #fff3e0;
            border: 1px solid #ff9800;
            border-radius: 10px;
            padding: 15px;
            margin-bottom: 20px;
            font-family: 'Courier New', monospace;
        }

        .formula-box h4 {
            color: #e65100;
            margin-bottom: 10px;
        }