/* 全局样式 */
:root {
    --primary-color: #4caf50;
    --secondary-color: #2e7d32;
    --text-color: #333;
    --light-gray: #f5f5f5;
    --border-color: #ddd;
    --success-color: #4caf50;
    --warning-color: #ff9800;
    --danger-color: #f44336;
    --info-color: #2196f3;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Microsoft YaHei', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: #fff;
}

/* 导航栏样式 */
.header {
    background-color: #fff;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
}

.nav {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.nav-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 60px;
}

.nav-logo a {
    color: var(--text-color);
    text-decoration: none;
    font-size: 20px;
    font-weight: bold;
}

.nav-menu ul {
    display: flex;
    list-style: none;
}

.nav-menu li {
    margin: 0 15px;
}

.nav-menu a {
    color: var(--text-color);
    text-decoration: none;
    font-size: 16px;
}

.nav-menu a:hover {
    color: var(--primary-color);
}

.nav-right a {
    text-decoration: none;
    margin-left: 20px;
}

.login-btn {
    color: var(--text-color);
}

.register-btn {
    color: #fff;
    background-color: var(--primary-color);
    padding: 8px 20px;
    border-radius: 4px;
}

.menu-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
}

/* 主要内容区样式 */
main {
    margin-top: 80px;
    padding: 20px;
}

.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 20px;
}

h1 {
    text-align: center;
    color: var(--primary-color);
    margin-bottom: 30px;
}

.intro {
    background-color: var(--light-gray);
    padding: 20px;
    border-radius: 8px;
    margin-bottom: 30px;
}

.intro h2 {
    color: var(--secondary-color);
    margin-bottom: 15px;
}

.intro ul {
    list-style-position: inside;
    margin-top: 10px;
}

/* 计算器表单样式 */
.calculator {
    background-color: #fff;
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    margin-bottom: 30px;
}

.calc-tabs {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
}

.tab-btn {
    padding: 10px 20px;
    border: none;
    background-color: var(--light-gray);
    border-radius: 4px;
    cursor: pointer;
    font-size: 16px;
    transition: all 0.3s;
}

.tab-btn.active {
    background-color: var(--primary-color);
    color: #fff;
}

.calc-content {
    display: block;
}

.calc-content.hidden {
    display: none;
}

.input-group {
    margin-bottom: 20px;
}

.input-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: bold;
}

.input-group input[type="number"],
.input-group input[type="text"] {
    width: 100%;
    padding: 10px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 16px;
}

.radio-group {
    display: flex;
    gap: 20px;
}

.radio-label {
    display: flex;
    align-items: center;
    cursor: pointer;
}

.radio-label input {
    margin-right: 8px;
}

.calculate-btn {
    background-color: var(--primary-color);
    color: #fff;
    border: none;
    padding: 12px 30px;
    border-radius: 4px;
    cursor: pointer;
    font-size: 16px;
    width: 100%;
    transition: background-color 0.3s;
}

.calculate-btn:hover {
    background-color: var(--secondary-color);
}

/* 结果显示样式 */
.result {
    background-color: #fff;
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    margin-bottom: 30px;
}

.result h3 {
    color: var(--secondary-color);
    margin-bottom: 20px;
    text-align: center;
}

.result-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.result-item {
    padding: 15px;
    border-radius: 8px;
    text-align: center;
}

.result-item h4 {
    margin-bottom: 10px;
    color: var(--primary-color);
}

.bmi-result {
    background-color: #e8f5e9;
}

.weight-result {
    background-color: #e3f2fd;
}

.standard-result {
    background-color: #fff3e0;
}

.bodyfat-result {
    background-color: #f1f8e9;
}

/* 健康指数仪表盘 */
.health-meter {
    margin: 30px 0;
    padding: 20px;
    background-color: var(--light-gray);
    border-radius: 8px;
}

.meter-container {
    position: relative;
    margin-top: 20px;
    height: 40px;
}

.meter {
    display: flex;
    height: 20px;
    border-radius: 10px;
    overflow: hidden;
}

.meter-section {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
    color: white;
    font-size: 12px;
    font-weight: bold;
}

.underweight {
    background-color: #64b5f6;
}

.normal {
    background-color: #66bb6a;
}

.overweight {
    background-color: #ffa726;
}

.obese {
    background-color: #ef5350;
}

.severe-obese {
    background-color: #d32f2f;
}

.meter-pointer {
    position: absolute;
    top: -10px;
    left: 0;
    width: 2px;
    height: 40px;
    background-color: #000;
    transform: translateX(-50%);
    transition: left 0.5s ease;
}

/* 健康建议样式 */
.health-advice {
    margin: 30px 0;
    padding: 20px;
    background-color: var(--light-gray);
    border-radius: 8px;
}

.health-advice-content {
    margin-top: 15px;
}

/* 热量需求样式 */
.calorie-needs {
    margin: 30px 0;
    padding: 20px;
    background-color: var(--light-gray);
    border-radius: 8px;
}

.calorie-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 20px;
    margin-top: 20px;
}

.calorie-item {
    background-color: #fff;
    padding: 15px;
    border-radius: 4px;
    text-align: center;
}

.calorie-item h5 {
    margin-bottom: 10px;
    color: var(--primary-color);
}

/* 使用说明样式 */
.tips {
    background-color: var(--light-gray);
    padding: 20px;
    border-radius: 8px;
    margin-bottom: 30px;
}

.tips h3 {
    color: var(--secondary-color);
    margin-bottom: 15px;
}

.tips ol {
    margin-left: 20px;
    margin-bottom: 20px;
}

.warning {
    background-color: #fff3cd;
    border: 1px solid #ffeeba;
    padding: 15px;
    border-radius: 4px;
    margin-top: 20px;
}

.warning p {
    color: #856404;
}

/* BMI表格样式 */
.bmi-chart {
    margin: 30px 0;
}

.bmi-chart h3 {
    color: var(--secondary-color);
    margin-bottom: 15px;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 15px;
}

th, td {
    padding: 12px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

th {
    background-color: var(--primary-color);
    color: white;
}

tr:nth-child(even) {
    background-color: var(--light-gray);
}

/* 广告位样式 */
.ad-container {
    max-width: 1200px;
    margin: 30px auto;
    padding: 0 20px;
}

.ad-content {
    background-color: var(--light-gray);
    padding: 20px;
    text-align: center;
    border-radius: 8px;
}

/* 底部版权样式 */
.footer {
    background-color: #f8f9fa;
    padding: 20px 0;
    text-align: center;
    margin-top: 50px;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.footer p {
    margin: 5px 0;
    color: #666;
}

.footer a {
    color: #666;
    text-decoration: none;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
        position: absolute;
        top: 60px;
        left: 0;
        width: 100%;
        background-color: #fff;
        padding: 20px;
        box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    }

    .nav-menu.active {
        display: block;
    }

    .nav-menu ul {
        flex-direction: column;
    }

    .nav-menu li {
        margin: 10px 0;
    }

    .menu-toggle {
        display: block;
    }

    .calc-tabs {
        flex-direction: column;
    }

    .result-grid {
        grid-template-columns: 1fr;
    }

    .calorie-grid {
        grid-template-columns: 1fr;
    }

    .radio-group {
        flex-direction: column;
        gap: 10px;
    }
}

/* 动画效果 */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.result.show {
    animation: fadeIn 0.5s ease-out;
}

/* 分享按钮样式 */
.share-section {
    text-align: center;
    margin: 30px 0;
    padding: 20px;
    background-color: var(--light-gray);
    border-radius: 8px;
}

.share-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 12px 24px;
    border-radius: 24px;
    cursor: pointer;
    font-size: 16px;
    transition: all 0.3s ease;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.share-btn:hover {
    background-color: var(--secondary-color);
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0,0,0,0.2);
}

.share-tip {
    margin-top: 10px;
    color: #666;
    font-size: 14px;
}