/* 背景样式文件 - 独立管理背景相关样式 */

/* 主体背景 */
body {
    background: linear-gradient(135deg, #e8f5e8 0%, #f0f8f0 25%, #e1f5e1 50%, #f5f9f5 75%, #e8f5e8 100%);
    background-size: 400% 400%;
    animation: gradientShift 15s ease infinite;
    position: relative;
    overflow-x: hidden;
}

/* 背景动画 */
@keyframes gradientShift {
    0% {
        background-position: 0% 50%;
    }
    50% {
        background-position: 100% 50%;
    }
    100% {
        background-position: 0% 50%;
    }
}

/* 装饰性背景元素 */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: 
        radial-gradient(circle at 20% 80%, rgba(144, 238, 144, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(152, 251, 152, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 40% 40%, rgba(173, 255, 173, 0.08) 0%, transparent 50%);
    pointer-events: none;
    z-index: -2;
}

/* 浮动装饰圆点 */
body::after {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image:
        radial-gradient(2px 2px at 20px 30px, rgba(76, 175, 80, 0.3), transparent),
        radial-gradient(2px 2px at 40px 70px, rgba(129, 199, 132, 0.3), transparent),
        radial-gradient(1px 1px at 90px 40px, rgba(165, 214, 167, 0.3), transparent),
        radial-gradient(1px 1px at 130px 80px, rgba(200, 230, 201, 0.3), transparent),
        radial-gradient(2px 2px at 160px 30px, rgba(76, 175, 80, 0.2), transparent);
    background-repeat: repeat;
    background-size: 200px 100px;
    animation: floatDots 20s linear infinite;
    pointer-events: none;
    z-index: -1;
}

@keyframes floatDots {
    0% {
        transform: translateY(0px);
    }
    100% {
        transform: translateY(-100px);
    }
}

/* 容器背景增强 */
.container {
    background: rgba(255, 255, 255, 0.02);
    backdrop-filter: blur(10px);
    border-radius: 20px;
    position: relative;
}

/* 表单区域背景 */
.form-section {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    border: 1px solid rgba(144, 238, 144, 0.3);
    position: relative;
    overflow: hidden;
}

.form-section::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: linear-gradient(45deg, transparent, rgba(144, 238, 144, 0.05), transparent);
    animation: shimmer 3s ease-in-out infinite;
    pointer-events: none;
}

@keyframes shimmer {
    0% {
        transform: translateX(-100%) translateY(-100%) rotate(45deg);
    }
    50% {
        transform: translateX(100%) translateY(100%) rotate(45deg);
    }
    100% {
        transform: translateX(-100%) translateY(-100%) rotate(45deg);
    }
}

/* 结果卡片背景 */
.basic-info-card,
.bmi-card,
.weight-card,
.metabolism-card,
.body-fat-card,
.measurements-card,
.advice-card {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(15px);
    border: 1px solid rgba(144, 238, 144, 0.2);
    position: relative;
    overflow: hidden;
}

/* 卡片悬停背景效果 */
.basic-info-card:hover,
.bmi-card:hover,
.weight-card:hover,
.metabolism-card:hover,
.body-fat-card:hover,
.measurements-card:hover,
.advice-card:hover {
    background: rgba(255, 255, 255, 0.98);
    border-color: rgba(76, 175, 80, 0.4);
}

/* 免责声明卡片背景 */
.disclaimer-card {
    background: rgba(255, 243, 205, 0.95);
    backdrop-filter: blur(15px);
    border: 1px solid rgba(255, 234, 167, 0.5);
}

/* 错误区域背景 */
.error-content {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    border: 1px solid rgba(220, 53, 69, 0.2);
}

/* 输入框背景 */
.form-input,
.form-select {
    background: rgba(248, 255, 248, 0.9);
    backdrop-filter: blur(10px);
}

.form-input:focus,
.form-select:focus {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(15px);
}

/* 信息项背景 */
.info-item {
    background: rgba(248, 255, 248, 0.8);
    backdrop-filter: blur(5px);
}

/* BMI分类背景 */
.bmi-category {
    background: rgba(232, 245, 232, 0.9);
    backdrop-filter: blur(10px);
}

/* 健康建议列表项背景 */
.health-tips li {
    background: rgba(248, 255, 248, 0.8);
    backdrop-filter: blur(5px);
}

/* 按钮背景增强 */
.submit-btn {
    position: relative;
    overflow: hidden;
}

.submit-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.5s;
}

.submit-btn:hover::before {
    left: 100%;
}

/* 重置按钮背景 */
.reset-btn {
    background: rgba(232, 245, 232, 0.9);
    backdrop-filter: blur(10px);
}

.reset-btn:hover {
    background: rgba(212, 237, 218, 0.95);
}

/* 响应式背景调整 */
@media (max-width: 767px) {
    body::after {
        background-size: 150px 75px;
        animation-duration: 15s;
    }
    
    .form-section::before {
        animation-duration: 2s;
    }
}

@media (min-width: 768px) and (max-width: 1024px) {
    body::after {
        background-size: 180px 90px;
        animation-duration: 18s;
    }
}

@media (min-width: 1024px) {
    body::after {
        background-size: 220px 110px;
        animation-duration: 25s;
    }
    
    .container {
        background: rgba(255, 255, 255, 0.05);
    }
}