BMI 计算器
        

            你的身高(cm)
            
        
        

            你的体重(kg)
            
        
        计算 BMI
        

    

    <script>
        function calculateBMI() {
            const height = parseFloat(document.getElementById('height').value);
            const weight = parseFloat(document.getElementById('weight').value);

            if (isNaN(height) || isNaN(weight) || height <= 0 || weight <= 0) {
                alert('请输入有效的身高和体重值。');
                return;
            }

            const bmi = (weight / ((height / 100) * (height / 100))).toFixed(2);
            let category = '';
            let message = '';
            let resultBg = '';

            if (bmi < 18.5 category='偏瘦' message='风一吹，你怕是要像风筝一样飘走咯！' resultbg='getComputedStyle(document.documentElement).getPropertyValue('--underweight-bg');' else if bmi>= 18.5 && bmi < 24 category='正常' message='嘿，你这身材，老天爷赏饭吃的 “刚刚好” 呀！' resultbg='getComputedStyle(document.documentElement).getPropertyValue('--normal-bg');' else if bmi>= 24 && bmi < 28) {
                category = '超重';
                message = '再胖点，你能去给熊猫当替身咯！';
                resultBg = getComputedStyle(document.documentElement).getPropertyValue('--overweight-bg');
            } else {
                category = '肥胖';
                message = '你不是胖，你是可爱到膨胀啦';
                resultBg = getComputedStyle(document.documentElement).getPropertyValue('--obese-bg');
            }

            const resultDiv = document.getElementById('result');
            resultDiv.innerHTML = `你的 BMI 值是：${bmi}，体重分类：${category}`;
            resultDiv.style.display = 'block';
            resultDiv.style.backgroundColor = resultBg;

            generateDanmaku(message);
        }

        function generateDanmaku(message) {
            const numDanmaku = Math.floor(window.innerHeight / 50);
            for (let i = 0; i < numdanmaku i const danmaku='document.createElement('div');' danmaku.classlist.adddanmaku danmaku.style.top='`${i' 50px danmaku.style.setproperty--random-hue math.random danmaku.style.animationduration='`${Math.random()' 8 4s danmaku.textcontent='message;' document.body.appendchilddanmaku danmaku.addeventlisteneranimationend> {
                    danmaku.remove();
                });
            }
        }
    </script>