/* 全局样式 */
:root {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

/* 导航栏样式 */
.nav-link {
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 3px;
    background-color: #3B82F6;
    transition: width 0.3s ease;
}

.nav-link:hover::after {
    width: 100%;
}

.nav-link.active::after {
    width: 100%;
}

/* 头图渐变动画 */
.hero-section {
    height: 360px !important; /* 减小头图高度 */
    background-size: 400% 400%;
    animation: gradientBG 15s ease infinite;
}

@keyframes gradientBG {
    0% {
        background-position: 0% 50%;
    }
    50% {
        background-position: 100% 50%;
    }
    100% {
        background-position: 0% 50%;
    }
}

/* 时间轴动画效果 */
.timeline-item {
    opacity: 0;
    transform: translateY(20px);
    transition: all 0.6s ease;
}

.timeline-item.show {
    opacity: 1;
    transform: translateY(0);
}

.timeline-item:hover {
    transform: scale(1.02);
}

.timeline-dot {
    transition: all 0.3s ease;
}

.timeline-item:hover .timeline-dot {
    transform: scale(1.2);
    box-shadow: 0 0 15px rgba(59, 130, 246, 0.5);
}

.timeline-content {
    transition: all 0.3s ease;
}

.timeline-content .course-title {
    font-size: 0.875rem;
    line-height: 1.25;
    margin-bottom: 0.5rem;
    color: #374151;
}

.timeline-content .course-subtitle {
    font-size: 0.75rem;
    line-height: 1.4;
    color: #6B7280;
    display: block;
    margin-bottom: 0.25rem;
}

.timeline-content .course-detail {
    font-size: 0.75rem;
    line-height: 1.4;
    color: #6B7280;
    display: block;
}

.timeline-item:hover .timeline-content {
    transform: translateX(5px);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

/* 时间轴连接线动画 */
.timeline-line {
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 2px;
    background: #E5E7EB;
    transform: scaleY(0);
    transform-origin: top;
    transition: transform 1s ease;
}

.timeline-line.show {
    transform: scaleY(1);
}

/* 卡片悬浮效果 */
.hover\:shadow-xl:hover {
    transform: translateY(-3px);
    transition: all 0.3s ease;
}

/* 内容区域间距调整 */
.section-spacing {
    padding-top: 3rem;
    padding-bottom: 3rem;
}

.card-grid {
    gap: 1.5rem;
}

/* 时间轴样式优化 */
.timeline-item {
    margin-bottom: 1.5rem;
}

.timeline-dot {
    width: 1.5rem;
    height: 1.5rem;
}

/* 响应式调整 */
@media (max-width: 768px) {
    .hero-section {
        height: 300px !important;
    }
    
    .section-spacing {
        padding-top: 2rem;
        padding-bottom: 2rem;
    }
}

/* 学习心得卡片样式 */
.testimonial-card {
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.testimonial-card::before {
    content: '"';
    position: absolute;
    top: 0.5rem;
    left: 1rem;
    font-size: 4rem;
    color: rgba(59, 130, 246, 0.1);
    font-family: serif;
    line-height: 1;
}

.testimonial-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.1);
}

.testimonial-content {
    position: relative;
    z-index: 1;
}

.testimonial-author {
    border-top: 1px solid rgba(0, 0, 0, 0.05);
    padding-top: 0.75rem;
    margin-top: 0.75rem;
}

.testimonial-role {
    color: #6B7280;
    font-size: 0.75rem;
}

/* 页脚布局优化 */
.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 4rem;
    align-items: start;
}

@media (max-width: 768px) {
    .footer-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
}

.footer-section {
    padding: 0;
}

.footer-section:last-child {
    justify-self: start;
}

/* 页脚视觉优化 */
footer {
    background: linear-gradient(135deg, #1f2937 0%, #374151 100%);
    position: relative;
}

footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(59, 130, 246, 0.5), transparent);
}

.footer-section h3,
.footer-section h4 {
    color: #f8fafc;
    margin-bottom: 1rem;
}

.footer-section h3 {
    font-size: 1.1rem;
    font-weight: 700;
}

.footer-section h4 {
    font-size: 1rem;
    font-weight: 600;
}

.footer-contact-item {
    display: flex;
    align-items: center;
    margin-bottom: 0.75rem;
    padding: 0.5rem;
    border-radius: 0.375rem;
    transition: all 0.3s ease;
}

.footer-contact-item:hover {
    background-color: rgba(59, 130, 246, 0.1);
    transform: translateX(5px);
}

.footer-contact-item .emoji {
    margin-right: 0.75rem;
    font-size: 1rem;
}

.footer-link {
    display: block;
    padding: 0.5rem;
    border-radius: 0.375rem;
    transition: all 0.3s ease;
    margin-bottom: 0.25rem;
}

.footer-link:hover {
    background-color: rgba(59, 130, 246, 0.1);
    color: #60a5fa !important;
    transform: translateX(5px);
}

.footer-copyright {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    margin-top: 2rem;
    padding-top: 1.5rem;
    text-align: center;
    color: #D1D5DB;
    font-size: 0.875rem;
}

/* 照片预览区域样式 */
.preview-photo-item {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    cursor: pointer;
    transition: all 0.3s ease;
    aspect-ratio: 1;
}

.preview-photo-item:hover {
    transform: translateY(-5px) scale(1.02);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
}

.preview-placeholder {
    height: 100%;
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    border: 2px dashed #cbd5e1;
    color: #64748b;
    transition: all 0.3s ease;
}

.preview-photo-item:hover .preview-placeholder {
    background: linear-gradient(135deg, #dbeafe 0%, #bfdbfe 100%);
    border-color: #3b82f6;
    color: #1e40af;
}

.preview-photo-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s ease;
}

.preview-photo-item:hover img {
    transform: scale(1.05);
}

.view-more-btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 24px;
    background: linear-gradient(135deg, #3b82f6 0%, #1d4ed8 100%);
    color: white;
    text-decoration: none;
    border-radius: 25px;
    font-weight: 500;
    transition: all 0.3s ease;
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.2);
}

.view-more-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(59, 130, 246, 0.3);
    background: linear-gradient(135deg, #2563eb 0%, #1d4ed8 100%);
}

/* 响应式优化 */
@media (max-width: 768px) {
    .preview-photo-item {
        aspect-ratio: 1.2;
    }
    
    .view-more-btn {
        font-size: 14px;
        padding: 10px 20px;
    }
}