<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>BMI 计算器</title>
<style>
:root {
--body-bg-start: #e8eaf6;
--body-bg-end: #d1c4e9;
--card-bg: rgba(255, 255, 255, 0.9);
--button-gradient-start: #7e57c2;
--button-gradient-end: #9575cd;
--button-hover-gradient-start: #673ab7;
--button-hover-gradient-end: #8e67c7;
--input-border: #bdbdbd;
--input-focus-border: #7e57c2;
--underweight-bg: #b3e5fc;
--normal-bg: #c8e6c9;
--overweight-bg: #ffe0b2;
--obese-bg: #ffcdd2;
--text-color: #212121;
--shadow-color: rgba(0, 0, 0, 0.1);
}
body {
font-family: 'Roboto', sans-serif;
background: linear-gradient(to bottom, var(--body-bg-start), var(--body-bg-end));
color: var(--text-color);
display: flex;
justify-content: center;
align-items: center;
min-height: 100vh;
margin: 0;
}
.card {
background-color: var(--card-bg);
border-radius: 20px;
box-shadow: 0 16px 32px var(--shadow-color);
padding: 60px;
width: 90%;
max-width: 700px;
box-sizing: border-box;
}
h1 {
text-align: center;
font-size: 32px;
margin-bottom: 40px;
}
.input-group {
margin-bottom: 30px;
}
label {
display: block;
margin-bottom: 12px;
font-size: 20px;
font-weight: 500;
}
input[type="number"] {
width: 100%;
padding: 18px;
border: 1px solid var(--input-border);
border-radius: 10px;
transition: border-color 0.3s ease;
font-size: 18px;
box-sizing: border-box;
}
input[type="number"]:focus {
border-color: var(--input-focus-border);
outline: none;
}
button {
width: 100%;
padding: 18px;
background: linear-gradient(to right, var(--button-gradient-start), var(--button-gradient-end));
color: white;
border: none;
border-radius: 10px;
box-shadow: 0 8px 16px var(--shadow-color);
cursor: pointer;
transition: background 0.3s ease;
font-size: 20px;
font-weight: 500;
}
button:hover {
background: linear-gradient(to right, var(--button-hover-gradient-start), var(--button-hover-gradient-end));
}
#result {
margin-top: 40px;
padding: 30px;
border-radius: 10px;
text-align: center;
display: none;
font-size: 22px;
}
#result .bmi-value {
font-size: 32px;
font-weight: 700;
}
.danmaku {
position: fixed;
top: 0;
right: 0;
pointer-events: none;
z-index: 999;
white-space: nowrap;
padding: 16px 32px;
border-radius: 30px;
color: white;
background-color: hsl(calc(var(--random-hue, 0) * 360), 30%, 60%);
animation: danmakuMove linear;
}
@keyframes danmakuMove {
from {
transform: translateX(100%);
}
to {
transform: translateX(-100vw);
}
}
</style>
</head>
<body>
<div class="card">
<h1>BMI 计算器</h1>
<div class="input-group">
<label for="height">你的身高(cm)</label>
<input type="number" id="height" placeholder="请输入身高">
</div>
<div class="input-group">
<label for="weight">你的体重(kg)</label>
<input type="number" id="weight" placeholder="请输入体重">
</div>
<button onclick="calculateBMI()">计算 BMI</button>
<div id="result"></div>
</div>
<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：<span class="bmi-value">${bmi}</span>，体重分类：${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.add('danmaku');
danmaku.style.top = `${i * 50}px`;
danmaku.style.setProperty('--random-hue', Math.random());
danmaku.style.animationDuration = `${Math.random() * 8 + 4}s`;
danmaku.textContent = message;
document.body.appendChild(danmaku);
danmaku.addEventListener('animationend', () => {
danmaku.remove();
});
}
}
</script>
</body>
</html>
