/* 全局样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: "Microsoft YaHei", "PingFang SC", "Hiragino Sans GB", "Heiti SC", sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #fff;
}

a {
    color: #0056b3;
    text-decoration: none;
    transition: color 0.3s;
}

a:hover {
    color: #004494;
}

/* 容器 */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* 按钮 */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    font-weight: 500;
    text-align: center;
    white-space: nowrap;
    vertical-align: middle;
    cursor: pointer;
    user-select: none;
    border: 1px solid transparent;
    border-radius: 4px;
    transition: all 0.3s;
    background-color: #0056b3;
    color: white;
}

.btn:hover {
    background-color: #004494;
    color: white;
}

.btn-outline {
    background-color: transparent;
    border: 1px solid #0056b3;
    color: #0056b3;
}

.btn-outline:hover {
    background-color: #0056b3;
    color: white;
}

.btn-light {
    background-color: white;
    color: #0056b3;
}

.btn-light:hover {
    background-color: #f8f9fa;
}

/* 表单 */
.form-group {
    margin-bottom: 1.5rem;
}

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: #333;
}

.form-control {
    display: block;
    width: 100%;
    padding: 0.75rem;
    font-size: 1rem;
    line-height: 1.5;
    color: #333;
    background-color: #fff;
    background-clip: padding-box;
    border: 1px solid #ced4da;
    border-radius: 4px;
    transition: border-color 0.3s, box-shadow 0.3s;
}

.form-control:focus {
    border-color: #0056b3;
    outline: 0;
    box-shadow: 0 0 0 0.2rem rgba(0, 86, 179, 0.25);
}

.form-check {
    position: relative;
    display: block;
    padding-left: 1.25rem;
}

.form-check-input {
    position: absolute;
    margin-top: 0.3rem;
    margin-left: -1.25rem;
}

.form-check-label {
    margin-bottom: 0;
}

/* 加载动画 */
.loading {
    display: inline-block;
    width: 1rem;
    height: 1rem;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: white;
    animation: spin 1s ease-in-out infinite;
    margin-right: 0.5rem;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

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

.navbar-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 1.5rem;
    max-width: 1200px;
    margin: 0 auto;
}

.navbar-logo {
    display: flex;
    align-items: center;
}

.navbar-logo img {
    height: 40px;
    margin-right: 1rem;
}

.navbar-logo h1 {
    font-size: 1.5rem;
    font-weight: 600;
    color: #333;
}

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

.navbar-item {
    margin-left: 1.5rem;
}

.navbar-link {
    color: #333;
    font-weight: 500;
    transition: color 0.3s;
}

.navbar-link:hover,
.navbar-link.active {
    color: #0056b3;
}

.navbar-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    color: #333;
    cursor: pointer;
}

/* 页脚 */
.footer {
    background-color: #f8f9fa;
    padding: 3rem 0 1rem;
}

.footer-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

.footer-logo img {
    height: 40px;
    margin-bottom: 1rem;
}

.footer-description {
    color: #666;
    margin-bottom: 1.5rem;
}

.footer-social {
    display: flex;
    gap: 1rem;
}

.footer-social a {
    width: 40px;
    height: 40px;
    background-color: #e9ecef;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #333;
    transition: background-color 0.3s, color 0.3s;
}

.footer-social a:hover {
    background-color: #0056b3;
    color: white;
}

.footer-title {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    color: #333;
}

.footer-links {
    list-style: none;
}

.footer-links li {
    margin-bottom: 0.5rem;
}

.footer-links a {
    color: #666;
    transition: color 0.3s;
}

.footer-links a:hover {
    color: #0056b3;
}

.footer-contact {
    display: flex;
    align-items: flex-start;
    margin-bottom: 1rem;
}

.footer-contact i {
    color: #0056b3;
    margin-right: 1rem;
    margin-top: 0.25rem;
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    margin-top: 2rem;
    border-top: 1px solid #e9ecef;
    color: #666;
}

/* 页面标题 */
.page-header {
    margin-top: 70px;
    padding: 6rem 0;
    background-size: cover;
    background-position: center;
    color: white;
    text-align: center;
}

.page-header h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.page-header p {
    font-size: 1.2rem;
}

/* 章节标题 */
.section-title {
    text-align: center;
    margin-bottom: 3rem;
}

.section-title h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: #333;
}

.section-title p {
    font-size: 1.1rem;
    color: #666;
}

/* 卡片 */
.card {
    background-color: white;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s, box-shadow 0.3s;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.15);
}

.card-image {
    height: 200px;
    overflow: hidden;
}

.card-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s;
}

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

.card-content {
    padding: 1.5rem;
}

.card-title {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    color: #333;
}

.card-text {
    color: #666;
    margin-bottom: 1rem;
}

/* 淡入动画 */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s, transform 0.6s;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* 懒加载图片 */
.lazy-image {
    opacity: 0;
    transition: opacity 0.3s;
}

.lazy-image.loaded {
    opacity: 1;
}

/* 响应式设计 */
@media (max-width: 992px) {
    .navbar-menu {
        position: fixed;
        top: 70px;
        left: 0;
        width: 100%;
        background-color: white;
        flex-direction: column;
        align-items: center;
        padding: 1rem 0;
        box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
        transform: translateY(-100%);
        opacity: 0;
        transition: transform 0.3s, opacity 0.3s;
    }

    .navbar-menu.active {
        transform: translateY(0);
        opacity: 1;
    }

    .navbar-item {
        margin: 0.5rem 0;
    }

    .navbar-toggle {
        display: block;
    }

    .page-header h1 {
        font-size: 2.5rem;
    }

    .section-title h2 {
        font-size: 2rem;
    }
}

@media (max-width: 768px) {
    .page-header {
        padding: 4rem 0;
    }

    .page-header h1 {
        font-size: 2rem;
    }

    .page-header p {
        font-size: 1rem;
    }

    .section-title h2 {
        font-size: 1.75rem;
    }

    .section-title p {
        font-size: 1rem;
    }

    .card-image {
        height: 150px;
    }
}

@media (max-width: 576px) {
    .navbar-container {
        padding: 1rem;
    }

    .navbar-logo h1 {
        font-size: 1.25rem;
    }

    .page-header {
        padding: 3rem 0;
    }

    .page-header h1 {
        font-size: 1.75rem;
    }

    .section-title h2 {
        font-size: 1.5rem;
    }

    .btn {
        padding: 0.5rem 1rem;
        font-size: 0.9rem;
    }
}