.base-input-card {
            background: white;
            border-radius: 16px;
            padding: 1rem 1.2rem;
            margin-bottom: 1rem;
            box-shadow: 0 2px 8px rgba(0,0,0,0.05);
            transition: all 0.2s;
            border-left: 4px solid var(--primary-color);
        }
        .base-label {
            font-weight: 700;
            font-size: 1.1rem;
            margin-bottom: 0.5rem;
            display: flex;
            align-items: center;
            gap: 8px;
        }
        .base-badge {
            background-color: #eef2ff;
            color: #1e3a8a;
            border-radius: 40px;
            padding: 0.2rem 0.7rem;
            font-size: 0.7rem;
            font-weight: 500;
        }
        .base-input {
            font-family: 'Courier New', monospace;
            font-size: 1.2rem;
            border: 1px solid #ced4da;
            border-radius: 12px;
            padding: 0.6rem 0.8rem;
            width: 100%;
            transition: 0.1s;
        }
        .base-input:focus {
            border-color: var(--primary-color);
            outline: none;
            box-shadow: 0 0 0 3px rgba(70,130,180,0.2);
        }
        .invalid-feedback-custom {
            font-size: 0.75rem;
            color: #dc3545;
            margin-top: 0.3rem;
            display: block;
        }
        .decimal-preview {
            background: #f1f5f9;
            border-radius: 24px;
            padding: 0.8rem 1.2rem;
            font-family: monospace;
            font-size: 1rem;
            text-align: center;
            margin-top: 1.2rem;
        }
        .example-group {
            display: flex;
            flex-wrap: wrap;
            gap: 0.6rem;
            margin: 1rem 0;
        }
        .conversion-step {
            background-color: rgba(70, 130, 180, 0.05);
            border-left: 3px solid var(--primary-color);
            padding: 1rem;
            margin: 1.2rem 0;
            font-size: 0.9rem;
        }
        .math-theorem {
            background: #f8f9fa;
            padding: 1.2rem;
            border-radius: 12px;
            margin: 1.5rem 0;
        }
        .info-icon {
            color: #0d6efd;
            margin-right: 0.3rem;
        }