.tabs-nav { display: flex; gap: 10px; margin-bottom: 20px; }
        .tab-btn { flex: 1; padding: 10px; background: #e2e8f0; border: none; border-radius: 8px; font-weight: 600; font-size: 0.9rem; cursor: pointer; color: var(--text-muted); transition: all 0.2s; }
        .tab-btn.active { background: var(--primary-color); color: white; }

        .tab-content { display: none; }
        .tab-content.active { display: block; }

        .control-group { margin-bottom: 15px; }
        .control-group label { display: block; margin-bottom: 6px; font-weight: 600; font-size: 0.85rem; color: var(--text-main); }
        .date-input, .number-input, .select-input { width: 100%; padding: 10px; border: 1px solid var(--border-color); border-radius: 8px; font-size: 0.9rem; background: #fafafa; }
        .date-input:focus, .number-input:focus, .select-input:focus { outline: 2px solid var(--primary-color); background: #fff; }

        .action-btn { width: 100%; background-color: var(--primary-color); color: white; border: none; border-radius: 8px; padding: 12px; font-size: 1rem; font-weight: 600; cursor: pointer; transition: background-color 0.2s; margin-top: 10px; }
        .action-btn:hover { background-color: var(--primary-hover); }

        .preview-panel { background: #fff; flex: 1; padding: 25px; border-radius: var(--radius); box-shadow: 0 4px 12px rgba(0,0,0,0.08); border: 1px solid var(--border-color); display: flex; flex-direction: column; justify-content: center; }
        
        .result-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; margin-top: 10px; }
        .result-card { background: #f0f4f8; padding: 12px; border-radius: 8px; border: 1px solid var(--border-color); text-align: center; }
        .result-card span { display: block; font-size: 0.8rem; color: var(--text-muted); margin-bottom: 4px; }
        .result-card strong { font-size: 1.1rem; color: var(--text-main); }

        .single-result { background: #f0f4f8; padding: 15px; border-radius: 8px; border: 1px solid var(--border-color); text-align: center; margin-top: 10px; }
        .single-result strong { font-size: 1.2rem; color: var(--primary-color); }

        @media (max-width: 768px) { 
            .main-container { flex-direction: column; } 
            .result-grid { grid-template-columns: 1fr; }
        }