/* 全局样式 */
body {
    font-family: 'Microsoft YaHei', sans-serif;
    line-height: 1.6;
    color: #333;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* 导航栏样式 */
.navbar {
    background: linear-gradient(45deg, #007bff, #0056b3);
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    padding: 0.3rem 0.5rem;
}

.navbar-brand {
    font-weight: bold;
    font-size: 1.5rem;
}

.nav-link {
    font-weight: 500;
    padding: 0.5rem 0.8rem;
    font-size: 1.1rem;
    transition: color 0.3s;
    position: relative;
}

.nav-link:hover {
    color: #fff !important;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 2px;
    background: #fff;
    transition: all 0.3s ease;
    transform: translateX(-50%);
}

.nav-link:hover::after {
    width: 80%;
}

/* 主要内容区域 */
.container {
    flex: 1;
    padding-bottom: 3rem;
    max-width: 1200px;
    margin: 0 auto;
}

h1 {
    font-weight: bold;
    margin-bottom: 1rem;
    color: #2c3e50;
}

.lead {
    font-size: 1.25rem;
    color: #666;
    margin-bottom: 1.5rem;
}

.btn {
    border-radius: 4px;
    padding: 0.6rem 1.2rem;
    transition: all 0.3s ease;
}

.btn-primary {
    background: linear-gradient(45deg, #007bff, #0056b3);
    border: none;
    padding: 0.75rem 1.5rem;
    font-weight: 500;
}

.btn-primary:hover {
    background: linear-gradient(45deg, #0056b3, #003d80);
    transform: translateY(-2px);
}

/* 图片样式 */
.img-fluid {
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    transition: transform 0.3s;
}

.img-fluid:hover {
    transform: scale(1.02);
}

/* 页脚样式 */
footer {
    background-color: #343a40;
    color: #fff;
    padding: 0.8rem 0;
    margin-top: auto;
    width: 100%;
}

footer p {
    margin: 0;
    font-size: 12px;
}

/* 响应式调整 */
@media (max-width: 768px) {
    .container {
        padding: 0 1rem;
    }
    
    h1 {
        font-size: 2rem;
    }
    
    .lead {
        font-size: 1.1rem;
    }
    
    .navbar-brand {
        font-size: 1.2rem;
    }
    
    .nav-link {
        font-size: 1rem;
    }
    
    .placeholder-image {
        height: 200px;
    }
}

/* 图片占位样式 */
.lazy {
    background-color: #f5f5f5;
    min-height: 200px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #999;
    font-size: 14px;
}

.lazy::before {
    content: "加载中...";
}

/* 图片加载动画 */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.lazy.loaded {
    animation: fadeIn 0.3s ease-in;
}

/* 图片悬停效果 */
.card-img-top {
    transition: transform 0.3s ease;
}

.card-img-top:hover {
    transform: scale(1.05);
}

/* 占位图片样式 */
.placeholder-image {
    background: linear-gradient(45deg, #f8f9fa, #e9ecef);
    height: 300px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    color: #6c757d;
    border-radius: 4px;
    margin-bottom: 1rem;
    transition: all 0.3s ease;
}

.placeholder-image i {
    margin-bottom: 1rem;
}

.placeholder-image p {
    margin: 0;
    font-size: 1rem;
}

.placeholder-image:hover {
    background: linear-gradient(45deg, #e9ecef, #dee2e6);
}

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

.animate-fadeIn {
    animation: fadeIn 0.6s ease-out;
}

/* 卡片悬停效果 */
.card {
    transition: all 0.3s ease;
    border: none;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 4px 8px rgba(0,0,0,0.2);
}

/* 滚动条美化 */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: #f1f1f1;
}

::-webkit-scrollbar-thumb {
    background: #007bff;
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: #0056b3;
}

/* 返回顶部按钮 */
.back-to-top {
    position: fixed;
    bottom: 20px;
    right: 20px;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: linear-gradient(45deg, #007bff, #0056b3);
    color: white;
    border: none;
    cursor: pointer;
    display: none;
    box-shadow: 0 2px 10px rgba(0,0,0,0.2);
    transition: all 0.3s ease;
    z-index: 1000;
}

.back-to-top:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(0,0,0,0.3);
}

.back-to-top i {
    font-size: 1.2rem;
}