.calculator-container {
            background: #2a2d30;
            color: #f8f9fa;
            border-radius: 5px;
            box-shadow: 0 15px 35px rgba(0, 0, 0, 0.1);
            margin-top: 2rem;
            overflow: hidden;
        }

        .card-header {
            background: linear-gradient(45deg, #fdad35, #fdad35) !important;
        }

        .custom-input {
            background-color: #3c3f42 !important;
            color: #ccc !important;
            border: 2px solid #495057;
            border-radius: 8px;
        }

        .custom-input:focus {
            background-color: #3c3f42 !important;
            color: #ccc !important;
            border-color: #667eea;
            box-shadow: 0 0 0 0.2rem rgba(102, 126, 234, 0.25);
        }

        .custom-input::placeholder {
            color: #adb5bd !important;
        }

        .form-select.custom-input option {
            background-color: #3c3f42;
            color: #ccc;
        }

        .btn-primary {
            background: linear-gradient(45deg, #f19b2c, #d99236);
            border: none;
            font-weight: 600;
            width: 100%;
            border-radius: 5px !important;
        }

        .btn-primary:hover {
            background: linear-gradient(45deg, #787c8d, #52555c);
        }

        .result-box {
            animation: fadeIn 0.5s ease-in;
        }

        @keyframes fadeIn {
            from {
                opacity: 0;
                transform: translateY(20px);
            }

            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

        .formula-box {
            background: #f8f9fa;
            border: 1px solid #dee2e6;
            border-radius: 8px;
            padding: 15px;
            font-family: 'Courier New', monospace;
            font-size: 0.9rem;
            margin-top: 10px;
        }

        .math-formula {
            text-align: center;
            font-size: 1.1rem;
            line-height: 1.6;
        }

        .form-check-input:checked {
            background-color: #667eea;
            border-color: #667eea;
        }

        .alert-success {
            background-color: #d1edff;
            border-color: #667eea;
            color: #0c5460;
        }

        .info-box {
            background: #495057;
            border-radius: 8px;
            padding: 15px;
            margin-bottom: 20px;
        }

        .info-box h6 {
            color: #fdad35;
            margin-bottom: 10px;
        }

        .info-box ul {
            margin-bottom: 0;
            padding-left: 20px;
        }

        .info-box li {
            margin-bottom: 5px;
        }