Note: The standard due date is calculated using Naegele’s Rule: LMP + 280 days.

`; } // Format date as human-readable function formatDate(dateStr) { const options = { year: 'numeric', month: 'long', day: 'numeric' }; return new Date(dateStr).toLocaleDateString(undefined, options); } // PDF Export function generatePDF() { const { jsPDF } = window.jspdf; const doc = new jsPDF(); const resultText = document.getElementById('resultsArea').innerText.trim(); if (!resultText || resultText.includes("click")) { alert("No results to export. Please calculate first."); return; } doc.setFontSize(16); doc.text("Pregnancy Due Date Calculation Report", 10, 20); doc.setFontSize(12); const lines = resultText.split('\n'); let y = 30; lines.forEach(line => { doc.text(line, 10, y); y += 10; }); doc.save("Pregnancy_Due_Date_Report.pdf"); } // Attach event listeners document.getElementById('calculateBtn').addEventListener('click', calculateDueDate); document.getElementById('pdfBtn').addEventListener('click', generatePDF); document.getElementById('prevTab').addEventListener('click', () => { const visibleTab = document.querySelector('.tabcontent[style*="block"]'); const index = Array.from(document.querySelectorAll('.tabcontent')).indexOf(visibleTab); if (index > 0) showTab(document.querySelectorAll('.tabcontent')[index - 1].id); }); document.getElementById('nextTab').addEventListener('click', () => { const visibleTab = document.querySelector('.tabcontent[style*="block"]'); const index = Array.from(document.querySelectorAll('.tabcontent')).indexOf(visibleTab); if (index < document.querySelectorAll('.tabcontent').length - 1) showTab(document.querySelectorAll('.tabcontent')[index + 1].id); }); });