健康指标计算器

使用 HTML5、CSS3 和 JavaScript 构建一个基于医学标准的综合性健康指标计算器。创建一个简洁、可访问的界面，并配备分步式输入表单。实现精确的 BMI 计算，附带可视化分类标尺及健康风险评估。添加体脂率计算器，支持多种方法（美国海军法、Jackson-Pollock 法、BIA 模拟法）。使用多种公式（Hamwi 公式、Devine 公式、Robinson 公式、Miller 公式）计算理想体重范围。实现详细的热量需求计算器，包含基础代谢率（BMR）计算（采用 Harris-Benedict 方程、Mifflin-St Jeor 方程和 Katch-McArdle 方程）以及基于活动水平的每日总能量消耗（TDEE）计算。根据所计算出的各项指标，提供个性化健康建议。同时支持公制与英制单位，并实现无缝换算。支持用户档案与测量历史记录存储，并配备趋势可视化功能。生成交互式进度图表，直观展示各项指标随时间的变化情况。生成可打印/可导出的 PDF 报告，完整包含所有计算指标与健康建议。

Build a comprehensive health metrics calculator with HTML5, CSS3 and JavaScript based on medical standards. Create a clean, accessible interface with step-by-step input forms. Implement accurate BMI calculation with visual classification scale and health risk assessment. Add body fat percentage calculator using multiple methods (Navy, Jackson-Pollock, BIA simulation). Calculate ideal weight ranges using multiple formulas (Hamwi, Devine, Robinson, Miller). Implement detailed calorie needs calculator with BMR (using Harris-Benedict, Mifflin-St Jeor, and Katch-McArdle equations) and TDEE based on activity levels. Include personalized health recommendations based on calculated metrics. Support both metric and imperial units with seamless conversion. Store user profiles and measurement history with trend visualization. Generate interactive progress charts showing changes over time. Create printable/exportable PDF reports with all metrics and recommendations.