/* 背景样式文件 */

/* 主背景渐变 */
body {
    background: linear-gradient(135deg, #e8f5e8 0%, #f0f9f0 25%, #f8fdf8 50%, #e8f5e8 75%, #f0f9f0 100%);
    background-size: 400% 400%;
    animation: gradientShift 15s ease infinite;
    position: relative;
    overflow-x: hidden;
}

/* 背景渐变动画 */
@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(76, 175, 80, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(45, 90, 61, 0.08) 0%, transparent 50%),
        radial-gradient(circle at 40% 40%, rgba(76, 175, 80, 0.05) 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(45, 90, 61, 0.2), transparent),
        radial-gradient(1px 1px at 90px 40px, rgba(76, 175, 80, 0.4), transparent),
        radial-gradient(1px 1px at 130px 80px, rgba(45, 90, 61, 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;
    opacity: 0.6;
}

/* 圆点浮动动画 */
@keyframes floatDots {
    0% {
        transform: translateY(0px) translateX(0px);
    }
    33% {
        transform: translateY(-10px) translateX(5px);
    }
    66% {
        transform: translateY(5px) translateX(-5px);
    }
    100% {
        transform: translateY(0px) translateX(0px);
    }
}

/* 网格背景（可选，默认隐藏） */
.grid-background {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: 
        linear-gradient(rgba(76, 175, 80, 0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(76, 175, 80, 0.03) 1px, transparent 1px);
    background-size: 50px 50px;
    pointer-events: none;
    z-index: -3;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.grid-background.active {
    opacity: 1;
}

/* 响应式背景调整 */
@media (max-width: 768px) {
    body::after {
        background-size: 150px 75px;
        animation-duration: 25s;
    }
    
    body::before {
        background-image: 
            radial-gradient(circle at 30% 70%, rgba(76, 175, 80, 0.08) 0%, transparent 50%),
            radial-gradient(circle at 70% 30%, rgba(45, 90, 61, 0.06) 0%, transparent 50%);
    }
}

@media (max-width: 480px) {
    body {
        animation-duration: 20s;
    }
    
    body::after {
        background-size: 100px 50px;
        opacity: 0.4;
    }
}

/* 高对比度模式下的背景调整 */
@media (prefers-contrast: high) {
    body {
        background: #f8fdf8;
        animation: none;
    }
    
    body::before,
    body::after {
        display: none;
    }
}

/* 减少动画模式下的背景调整 */
@media (prefers-reduced-motion: reduce) {
    body {
        animation: none;
        background: linear-gradient(135deg, #e8f5e8 0%, #f0f9f0 50%, #f8fdf8 100%);
    }
    
    body::after {
        animation: none;
    }
    
    @keyframes gradientShift {
        0%, 100% {
            background-position: 0% 50%;
        }
    }
    
    @keyframes floatDots {
        0%, 100% {
            transform: translateY(0px) translateX(0px);
        }
    }
}

/* 深色模式支持 */
@media (prefers-color-scheme: dark) {
    body {
        background: linear-gradient(135deg, #1a2e1a 0%, #2d4a2d 25%, #1f3a1f 50%, #1a2e1a 75%, #2d4a2d 100%);
    }
    
    body::before {
        background-image: 
            radial-gradient(circle at 20% 80%, rgba(76, 175, 80, 0.15) 0%, transparent 50%),
            radial-gradient(circle at 80% 20%, rgba(144, 238, 144, 0.1) 0%, transparent 50%),
            radial-gradient(circle at 40% 40%, rgba(76, 175, 80, 0.08) 0%, transparent 50%);
    }
    
    body::after {
        background-image:
            radial-gradient(2px 2px at 20px 30px, rgba(144, 238, 144, 0.4), transparent),
            radial-gradient(2px 2px at 40px 70px, rgba(76, 175, 80, 0.3), transparent),
            radial-gradient(1px 1px at 90px 40px, rgba(144, 238, 144, 0.5), transparent),
            radial-gradient(1px 1px at 130px 80px, rgba(76, 175, 80, 0.4), transparent),
            radial-gradient(2px 2px at 160px 30px, rgba(144, 238, 144, 0.3), transparent);
    }
}

/* 打印样式 */
@media print {
    body {
        background: white !important;
        animation: none !important;
    }
    
    body::before,
    body::after {
        display: none !important;
    }
}

/* 特殊效果：鼠标悬停时的背景变化 */
@media (hover: hover) {
    .container:hover {
        position: relative;
    }
    
    .container:hover::before {
        content: '';
        position: absolute;
        top: -20px;
        left: -20px;
        right: -20px;
        bottom: -20px;
        background: radial-gradient(circle at var(--mouse-x, 50%) var(--mouse-y, 50%), rgba(76, 175, 80, 0.05) 0%, transparent 50%);
        border-radius: 30px;
        pointer-events: none;
        z-index: -1;
        transition: opacity 0.3s ease;
    }
}

/* 季节性主题变化（可通过JavaScript控制） */
.theme-spring body {
    background: linear-gradient(135deg, #e8f5e8 0%, #f0f9f0 25%, #e1f5e1 50%, #f8fdf8 75%, #e8f5e8 100%);
}

.theme-summer body {
    background: linear-gradient(135deg, #f0f9f0 0%, #e8f5e8 25%, #f8fdf8 50%, #e1f5e1 75%, #f0f9f0 100%);
}

.theme-autumn body {
    background: linear-gradient(135deg, #f5f0e8 0%, #f9f5f0 25%, #fdf8f0 50%, #f5f0e8 75%, #f9f5f0 100%);
}

.theme-winter body {
    background: linear-gradient(135deg, #f0f5f8 0%, #f5f9fc 25%, #f8fbfd 50%, #f0f5f8 75%, #f5f9fc 100%);
}

/* 性能优化：GPU加速 */
body,
body::before,
body::after {
    will-change: transform;
    transform: translateZ(0);
}

/* 无障碍支持：为屏幕阅读器隐藏装饰元素 */
body::before,
body::after {
    speak: none;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
}