/* 力学板块专门样式 */

/* 力学主题颜色 - 更换为更现代的颜色方案 */
:root {
    --mechanics-primary: #3498db;
    --mechanics-secondary: #2c3e50;
    --mechanics-accent: #e74c3c;
    --mechanics-light: #ecf0f1;
    --mechanics-dark: #34495e;
    --mechanics-metal: #95a5a6;
    --mechanics-success: #27ae60;
    --mechanics-warning: #f39c12;
}

/* 力学背景图案 */
body {
    background-image: 
        radial-gradient(circle at 25% 25%, rgba(52, 152, 219, 0.05) 0%, transparent 50%),
        radial-gradient(circle at 75% 75%, rgba(44, 62, 80, 0.05) 0%, transparent 50%);
    background-attachment: fixed;
    background-color: var(--mechanics-light);
}

/* 头部样式 - 力学主题 */
header {
    background: linear-gradient(135deg, var(--mechanics-secondary) 0%, var(--mechanics-primary) 100%);
    position: relative;
    overflow: hidden;
    padding: 4rem 0;
}

/* 力学头部装饰 - 牛顿运动定律图标 */
header::before {
    content: '';
    position: absolute;
    top: -20%;
    right: -10%;
    width: 200px;
    height: 200px;
    border: 3px solid rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    background: radial-gradient(circle, rgba(255, 255, 255, 0.1) 0%, transparent 70%);
    animation: orbit 20s linear infinite;
}

/* 力学装饰元素 - 力的矢量箭头 */
header::after {
    content: '→';
    position: absolute;
    bottom: -10%;
    left: 10%;
    font-size: 120px;
    color: rgba(255, 255, 255, 0.05);
    transform: rotate(45deg);
    font-weight: bold;
}

/* 轨道动画 */
@keyframes orbit {
    0% {
        transform: rotate(0deg) translateX(50px);
    }
    100% {
        transform: rotate(360deg) translateX(50px);
    }
}

/* 头部按钮容器 */
.header-actions {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1rem;
    flex-wrap: wrap;
    margin-top: 2rem;
    position: relative;
    z-index: 1;
}

/* 返回按钮样式 - 美化 */
.back-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 12px 24px;
    background: rgba(255, 255, 255, 0.15);
    color: white;
    text-decoration: none;
    border-radius: 25px;
    font-weight: 600;
    transition: all 0.3s ease;
    border: 2px solid rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    position: relative;
    overflow: hidden;
}

/* 返回按钮悬停效果 */
.back-link:hover {
    background: rgba(255, 255, 255, 0.25);
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.2);
    border-color: rgba(255, 255, 255, 0.4);
}

/* 返回按钮点击效果 */
.back-link:active {
    transform: translateY(0);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

/* 返回按钮图标 */
.back-link::before {
    content: '←';
    font-weight: bold;
}

/* 主容器样式 */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* 力学板块卡片样式 */
.experiment-categories {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
    margin: 3rem 0;
}

/* 分类卡片样式 */
.category {
    background: white;
    border-radius: 15px;
    padding: 2rem;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    position: relative;
    overflow: hidden;
    border: 1px solid rgba(52, 152, 219, 0.1);
}

/* 运动学卡片 */
#kinematics {
    --category-color: var(--mechanics-primary);
    --category-gradient: linear-gradient(135deg, var(--mechanics-primary), var(--mechanics-secondary));
    border-top: 4px solid var(--mechanics-primary);
}

/* 动力学卡片 */
#dynamics {
    --category-color: var(--mechanics-secondary);
    --category-gradient: linear-gradient(135deg, var(--mechanics-secondary), var(--mechanics-dark));
    border-top: 4px solid var(--mechanics-secondary);
}

/* 动量能量卡片 */
#momentum-energy {
    --category-color: var(--mechanics-accent);
    --category-gradient: linear-gradient(135deg, var(--mechanics-accent), var(--mechanics-primary));
    border-top: 4px solid var(--mechanics-accent);
}

/* 天体运动卡片 */
#celestial-motion {
    --category-color: var(--mechanics-dark);
    --category-gradient: linear-gradient(135deg, var(--mechanics-dark), var(--mechanics-secondary));
    border-top: 4px solid var(--mechanics-dark);
}

/* 分类卡片标题 */
.category h2 {
    display: flex;
    align-items: center;
    gap: 0.8rem;
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--category-color);
}

/* 分类卡片描述 */
.category p {
    margin-bottom: 1.5rem;
    color: #666;
    line-height: 1.6;
}

/* 力学卡片特殊装饰 - 物理公式 */
.category::after {
    content: '';
    position: absolute;
    top: 10px;
    right: 10px;
    width: 40px;
    height: 40px;
    border: 2px solid var(--category-color);
    border-radius: 4px;
    opacity: 0.1;
    transform: rotate(15deg);
}

/* 运动学卡片装饰 */
#kinematics::before {
    content: 'v = v₀ + at';
    position: absolute;
    top: 20px;
    right: 20px;
    font-size: 14px;
    color: var(--mechanics-primary);
    opacity: 0.3;
    font-family: 'Times New Roman', serif;
}

/* 动力学卡片装饰 */
#dynamics::before {
    content: 'F = ma';
    position: absolute;
    top: 20px;
    right: 20px;
    font-size: 14px;
    color: var(--mechanics-secondary);
    opacity: 0.3;
    font-family: 'Times New Roman', serif;
}

/* 动量能量卡片装饰 */
#momentum-energy::before {
    content: 'p = mv';
    position: absolute;
    top: 20px;
    right: 20px;
    font-size: 14px;
    color: var(--mechanics-accent);
    opacity: 0.3;
    font-family: 'Times New Roman', serif;
}

/* 天体运动卡片装饰 */
#celestial-motion::before {
    content: 'F = GmM/r²';
    position: absolute;
    top: 20px;
    right: 20px;
    font-size: 14px;
    color: var(--mechanics-dark);
    opacity: 0.3;
    font-family: 'Times New Roman', serif;
}

/* 实验按钮容器 */
.experiments {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
    gap: 1rem;
}

/* 力学实验按钮样式 - 美化 */
.experiment-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 16px;
    background: rgba(52, 152, 219, 0.1);
    color: var(--mechanics-secondary);
    text-decoration: none;
    border-radius: 8px;
    font-weight: 600;
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    border: 2px solid rgba(52, 152, 219, 0.2);
    position: relative;
    overflow: hidden;
    text-align: center;
    min-height: 48px;
}

/* 力学按钮悬停效果 */
.experiment-btn:hover {
    transform: translateY(-5px) scale(1.03);
    box-shadow: 0 10px 30px rgba(52, 152, 219, 0.3);
    background: var(--category-gradient);
    color: white;
    border-color: transparent;
}

/* 力学按钮点击效果 */
.experiment-btn:active {
    transform: translateY(-2px) scale(0.98);
    box-shadow: 0 5px 15px rgba(52, 152, 219, 0.2);
}

/* 力学主题的滚动条 */
::-webkit-scrollbar-thumb {
    background: linear-gradient(135deg, var(--mechanics-primary), var(--mechanics-secondary));
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: linear-gradient(135deg, var(--mechanics-secondary), var(--mechanics-primary));
}

/* 力学主题的动画效果 */
@keyframes forcePulse {
    0% {
        box-shadow: 0 0 0 0 rgba(52, 152, 219, 0.4);
    }
    70% {
        box-shadow: 0 0 0 20px rgba(52, 152, 219, 0);
    }
    100% {
        box-shadow: 0 0 0 0 rgba(52, 152, 219, 0);
    }
}

/* 力学卡片悬停动画 */
.category:hover {
    animation: forcePulse 2s infinite;
    transform: translateY(-8px);
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.15);
}

/* 响应式调整 */
@media (max-width: 768px) {
    .experiment-categories {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    .category {
        padding: 1.5rem;
    }
    
    .category h2 {
        font-size: 1.4rem;
    }
    
    .experiments {
        grid-template-columns: repeat(auto-fill, minmax(100px, 1fr));
        gap: 0.8rem;
    }
    
    header::before {
        width: 150px;
        height: 150px;
    }
    
    header::after {
        font-size: 80px;
    }
    
    .header-actions {
        flex-direction: column;
        align-items: stretch;
    }
    
    .back-link {
        justify-content: center;
    }
}

/* 力学主题的加载动画 */
@keyframes mechanicsLoad {
    0% {
        background-position: 0% 50%;
    }
    50% {
        background-position: 100% 50%;
    }
    100% {
        background-position: 0% 50%;
    }
}

/* 力学主题的加载效果 */
.loading {
    background: linear-gradient(
        90deg,
        var(--mechanics-light),
        var(--mechanics-primary),
        var(--mechanics-light)
    );
    background-size: 200% 100%;
    animation: mechanicsLoad 2s ease-in-out infinite;
}

/* 力学主题的涟漪效果 */
.ripple {
    background: rgba(52, 152, 219, 0.6);
}

/* 力学元素装饰 - 力的箭头 */
.force-arrow {
    position: absolute;
    width: 2px;
    height: 40px;
    background: var(--mechanics-primary);
    transform-origin: bottom;
    animation: forceVibration 3s ease-in-out infinite;
}

.force-arrow::after {
    content: '';
    position: absolute;
    top: 0;
    left: -4px;
    border-left: 5px solid transparent;
    border-right: 5px solid transparent;
    border-bottom: 8px solid var(--mechanics-primary);
}

@keyframes forceVibration {
    0%, 100% {
        transform: rotate(0deg);
    }
    50% {
        transform: rotate(5deg);
    }
}

/* 力学元素 - 弹簧效果 */
.spring {
    position: absolute;
    width: 60px;
    height: 20px;
    border: 2px solid var(--mechanics-metal);
    border-radius: 10px;
    animation: springCompress 2s ease-in-out infinite;
}

@keyframes springCompress {
    0%, 100% {
        transform: scaleX(1);
    }
    50% {
        transform: scaleX(0.8);
    }
}