/* 全局样式 */
:root {
    --primary-color: #0066cc;
    --secondary-color: #00a8ff;
    --accent-color: #ff6b35;
    --dark-color: #1a1a2e;
    --light-color: #f8f9fa;
    --text-color: #333;
    --border-radius: 10px;
    --box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    overflow-x: hidden;
}

/* 导航栏样式 */
#mainNav {
    /* background: rgba(26, 26, 46, 0.95); */
    /* backdrop-filter: blur(10px); */
    transition: var(--transition);
    padding: 1rem 0;
    color: #000;
}

#mainNav.navbar-scrolled {
    /* background: rgba(26, 26, 46, 0.98); */
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
}

.navbar-brand {
    display: flex;
    align-items: center;
    font-weight: 700;
    /* color: white !important; */
}

.navbar-brand img {
    transition: var(--transition);
}

.navbar-nav .nav-link {
    /* color: rgba(255, 255, 255, 0.8) !important; */
    font-weight: 500;
    margin: 0 0.5rem;
    transition: var(--transition);
    position: relative;
}

.navbar-nav .nav-link:hover,
.navbar-nav .nav-link.active {
    /* color: white !important; */
}

.navbar-nav .nav-link::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: -5px;
    left: 50%;
    background: var(--secondary-color);
    transition: var(--transition);
    transform: translateX(-50%);
}

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

/* Hero Section */
.hero-section {
    position: relative;
    background: linear-gradient(135deg, var(--dark-color) 0%, var(--primary-color) 100%);
    color: white;
    overflow: hidden;
}

.hero-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('https://images.unsplash.com/photo-1556089774-b83e46c0954b?ixlib=rb-4.0.3&auto=format&fit=crop&w=1950&q=80') center/cover;
    opacity: 0.3;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(26, 26, 46, 0.7);
}

.hero-section .container {
    position: relative;
    z-index: 2;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    background: linear-gradient(45deg, white, var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--secondary-color);
}

.hero-description {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.hero-buttons .btn {
    padding: 12px 30px;
    font-size: 1.1rem;
    border-radius: 50px;
    transition: var(--transition);
}

.hero-image img {
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    transform: perspective(1000px) rotateY(-5deg);
    transition: var(--transition);
}

.hero-image img:hover {
    transform: perspective(1000px) rotateY(0deg) scale(1.05);
}

/* Section Styles */
.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--dark-color);
}

.section-subtitle {
    font-size: 1.2rem;
    color: #666;
    margin-bottom: 3rem;
}

/* Feature Cards */
.feature-card {
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    transition: var(--transition);
    height: 100%;
}

.feature-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.15);
}

.feature-icon {
    color: var(--primary-color);
    transition: var(--transition);
}

.feature-card:hover .feature-icon {
    transform: scale(1.1);
    color: var(--secondary-color);
}

/* Course Cards */
.course-card {
    border: none;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    transition: var(--transition);
    overflow: hidden;
}

.course-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.15);
}

.course-card img {
    height: 200px;
    object-fit: cover;
    transition: var(--transition);
}

.course-card:hover img {
    transform: scale(1.1);
}

/* Stats Section */
.stat-item {
    padding: 2rem 0;
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.stat-label {
    font-size: 1.1rem;
    opacity: 0.9;
}

/* News Cards */
.news-card {
    background: white;
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--box-shadow);
    transition: var(--transition);
}

.news-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.15);
}

.news-image img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    transition: var(--transition);
}

.news-card:hover .news-image img {
    transform: scale(1.1);
}

.news-title {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.news-excerpt {
    color: #666;
    margin-bottom: 1rem;
}
/* footer背景 */
footer{
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));

}
/* CTA Section */
.cta-section {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
}
.banner-bg {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
}
.cta-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.cta-subtitle {
    font-size: 1.2rem;
    opacity: 0.9;
}

/* Footer */
footer {
    /* background: var(--dark-color) !important; */
}

.footer-brand img {
    filter: brightness(0) invert(1);
}

.social-links a {
    transition: var(--transition);
}

.social-links a:hover {
    color: var(--secondary-color) !important;
    transform: translateY(-3px);
}

/* Timeline Styles */
.timeline {
    position: relative;
    padding: 20px 0;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--primary-color);
    transform: translateX(-50%);
}

.timeline-item {
    position: relative;
    margin-bottom: 30px;
    padding-left: 50px;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: 50%;
    top: 20px;
    width: 20px;
    height: 20px;
    background: var(--primary-color);
    border-radius: 50%;
    transform: translateX(-50%);
    z-index: 1;
}

.timeline-content {
    background: white;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    margin-left: 20px;
}

.timeline-content h4 {
    color: var(--primary-color);
    margin-bottom: 10px;
}

/* Contact Page Styles */
.contact-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 70px;
    height: 70px;
    margin: 0 auto 15px;
    border-radius: 50%;
}

.cert-icon,
.value-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 15px;
}

.partner-logo {
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

/* Form Styles */
.form-control:focus,
.form-select:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 0.2rem rgba(0, 123, 255, 0.25);
}

.was-validated .form-control:valid {
    border-color: var(--success-color);
}

.was-validated .form-control:invalid {
    border-color: var(--danger-color);
}

/* Responsive Styles */
@media (max-width: 768px) {
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-subtitle {
        font-size: 1.2rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .navbar-nav {
        text-align: center;
        padding: 1rem 0;
    }
    
    .navbar-nav .nav-link {
        margin: 0.5rem 0;
    }
    
    .hero-buttons .btn {
        display: block;
        width: 100%;
        margin-bottom: 1rem;
    }
    
    .feature-card,
    .course-card,
    .news-card {
        margin-bottom: 2rem;
    }
    
    .timeline::before {
        left: 20px;
    }
    
    .timeline-item {
        padding-left: 50px;
    }
    
    .timeline-item::before {
        left: 20px;
    }
    
    .timeline-content {
        margin-left: 0;
    }
}

@media (max-width: 576px) {
    .hero-title {
        font-size: 2rem;
    }
    
    .container {
        padding-left: 1rem;
        padding-right: 1rem;
    }
    
    .btn {
        padding: 10px 20px;
        font-size: 1rem;
    }
}

/* Animation Classes */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.6s ease;
}

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

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 8px;
}

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

::-webkit-scrollbar-thumb {
    background: var(--primary-color);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--secondary-color);
}

/* News Detail Page Styles */
.news-article {
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    padding: 2.5rem;
    margin-bottom: 2rem;
}

.news-title {
    font-size: 2.2rem;
    font-weight: 700;
    color: var(--dark-color);
    line-height: 1.4;
    margin-bottom: 1.5rem;
}

.news-meta-detail {
    font-size: 0.95rem;
    color: #6c757d;
    padding-bottom: 1rem;
    border-bottom: 1px solid #e9ecef;
    margin-bottom: 2rem;
}

.news-meta-detail span {
    display: inline-flex;
    align-items: center;
}

.news-image {
    text-align: center;
    margin-bottom: 2rem;
}

.news-image img {
    border-radius: var(--border-radius);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    max-width: 100%;
    height: auto;
}

.image-caption {
    font-size: 0.9rem;
    color: #6c757d;
    font-style: italic;
}

.news-content {
    font-size: 1.1rem;
    line-height: 1.8;
    color: #333;
}

.news-content p {
    margin-bottom: 1.5rem;
}

.news-content h2,
.news-content h3,
.news-content h4 {
    color: var(--primary-color);
    margin: 2rem 0 1rem 0;
    font-weight: 600;
}

.news-content ul,
.news-content ol {
    margin-bottom: 1.5rem;
    padding-left: 2rem;
}

.news-content li {
    margin-bottom: 0.5rem;
}

.news-content blockquote {
    border-left: 4px solid var(--primary-color);
    padding-left: 1.5rem;
    margin: 2rem 0;
    font-style: italic;
    background: #f8f9fa;
    padding: 1.5rem;
    border-radius: 0 var(--border-radius) var(--border-radius) 0;
}

.news-tags .badge {
    font-size: 0.85rem;
    font-weight: 400;
    border-radius: 20px;
    transition: var(--transition);
}

.news-tags .badge:hover {
    background: var(--primary-color) !important;
    color: white !important;
    transform: translateY(-2px);
}

.news-share .btn {
    border-radius: 25px;
    font-size: 0.9rem;
    padding: 0.5rem 1rem;
    transition: var(--transition);
}

.news-share .btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
}

.news-navigation {
    background: #f8f9fa;
    border-radius: var(--border-radius);
    padding: 1.5rem;
    margin-top: 2rem;
}

.news-nav-item h6 {
    font-size: 1rem;
    font-weight: 500;
    margin-bottom: 0.5rem;
}

.news-nav-item a {
    color: var(--primary-color);
    text-decoration: none;
    transition: var(--transition);
}

.news-nav-item a:hover {
    color: var(--secondary-color);
    text-decoration: underline;
}

/* Sidebar Widgets */
.sidebar-widget {
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    padding: 1.5rem;
    margin-bottom: 2rem;
}

.widget-title {
    color: var(--dark-color);
    font-weight: 600;
    font-size: 1.2rem;
    padding-bottom: 0.75rem;
    border-bottom: 2px solid var(--primary-color);
    margin-bottom: 1.5rem;
}

.related-news-item {
    transition: var(--transition);
}

.related-news-item:hover {
    background: #f8f9fa;
    border-radius: 8px;
    padding: 0.5rem;
    margin: -0.5rem;
}

.related-news-item h6 {
    font-size: 0.95rem;
    font-weight: 500;
    line-height: 1.4;
    margin-bottom: 0.5rem;
}

.related-news-item a {
    color: var(--dark-color);
    text-decoration: none;
    transition: var(--transition);
}

.related-news-item a:hover {
    color: var(--primary-color);
}

.related-news-img {
    border-radius: 6px;
    transition: var(--transition);
}

.related-news-item:hover .related-news-img {
    transform: scale(1.05);
}

.hot-news-item {
    padding: 0.75rem 0;
    border-bottom: 1px solid #e9ecef;
    transition: var(--transition);
}

.hot-news-item:last-child {
    border-bottom: none;
}

.hot-news-item:hover {
    background: #f8f9fa;
    border-radius: 6px;
    padding-left: 0.5rem;
    padding-right: 0.5rem;
    margin: 0 -0.5rem;
}

.hot-news-number {
    color: var(--primary-color) !important;
    font-weight: 700;
    font-size: 1.1rem;
}

.hot-news-item h6 {
    font-size: 0.95rem;
    font-weight: 500;
    line-height: 1.4;
    margin-bottom: 0;
}

.hot-news-item a {
    color: var(--dark-color);
    text-decoration: none;
    transition: var(--transition);
}

.hot-news-item a:hover {
    color: var(--primary-color);
}

.contact-info {
    font-size: 0.95rem;
}

.contact-item {
    display: flex;
    align-items: center;
    transition: var(--transition);
}

.contact-item:hover {
    transform: translateX(5px);
}

.contact-item i {
    width: 20px;
    text-align: center;
    transition: var(--transition);
}

.contact-item:hover i {
    color: var(--secondary-color) !important;
    transform: scale(1.1);
}

/* Responsive News Detail */
@media (max-width: 768px) {
    .news-article {
        padding: 1.5rem;
    }
    
    .news-title {
        font-size: 1.8rem;
    }
    
    .news-meta-detail {
        font-size: 0.85rem;
        flex-direction: column;
        gap: 0.5rem;
    }
    
    .news-meta-detail span {
        margin-right: 0 !important;
    }
    
    .news-content {
        font-size: 1rem;
    }
    
    .sidebar-widget {
        margin-top: 2rem;
    }
    
    .news-navigation .row {
        gap: 1rem;
    }
    
    .news-navigation .col-md-6:last-child {
        text-align: left !important;
    }
}

@media (max-width: 576px) {
    .news-article {
        padding: 1rem;
    }
    
    .news-title {
        font-size: 1.5rem;
    }
    
    .news-content {
        font-size: 0.95rem;
    }
    
    .sidebar-widget {
        padding: 1rem;
    }
}