/* Activities Page Specific Styles */

.activities-hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 100px 0;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.activities-hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="activities-pattern" width="50" height="50" patternUnits="userSpaceOnUse"><circle cx="25" cy="25" r="2" fill="%23ffffff" opacity="0.1"/></pattern></defs><rect width="100" height="100" fill="url(%23activities-pattern)"/></svg>');
    opacity: 0.3;
}

.activities-hero h1 {
    font-size: 3.5rem;
    font-weight: 800;
    margin-bottom: 1rem;
    text-shadow: 2px 2px 8px rgba(0,0,0,0.3);
    position: relative;
    z-index: 2;
}

.activities-hero p {
    font-size: 1.3rem;
    opacity: 0.9;
    font-weight: 300;
    position: relative;
    z-index: 2;
}

.activity-filter {
    background: white;
    padding: 2rem 0;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    margin-bottom: 3rem;
}

.filter-btn {
    background: transparent;
    border: 2px solid var(--primary-color);
    color: var(--primary-color);
    padding: 0.75rem 1.5rem;
    border-radius: 25px;
    margin: 0.25rem;
    transition: all 0.3s ease;
    font-weight: 500;
}

.filter-btn:hover,
.filter-btn.active {
    background: var(--primary-color);
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(74, 144, 226, 0.3);
}

.activity-timeline {
    position: relative;
    padding: 2rem 0;
}

.activity-timeline::before {
    content: '';
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 4px;
    background: linear-gradient(to bottom, var(--primary-color), var(--secondary-color));
    transform: translateX(-50%);
}

.timeline-item {
    position: relative;
    margin-bottom: 3rem;
    opacity: 0;
    animation: fadeInUp 0.8s ease-out forwards;
}

.timeline-item:nth-child(even) {
    animation-delay: 0.2s;
}

.timeline-item:nth-child(odd) {
    animation-delay: 0.4s;
}

.timeline-content {
    background: white;
    padding: 2rem;
    border-radius: 15px;
    box-shadow: 0 5px 20px rgba(0,0,0,0.1);
    position: relative;
    transition: all 0.3s ease;
}

.timeline-content:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0,0,0,0.15);
}

.timeline-content::before {
    content: '';
    position: absolute;
    top: 20px;
    width: 0;
    height: 0;
    border: 15px solid transparent;
}

.timeline-item:nth-child(odd) .timeline-content {
    margin-right: 50%;
    margin-left: 2rem;
}

.timeline-item:nth-child(odd) .timeline-content::before {
    right: -30px;
    border-left-color: white;
}

.timeline-item:nth-child(even) .timeline-content {
    margin-left: 50%;
    margin-right: 2rem;
}

.timeline-item:nth-child(even) .timeline-content::before {
    left: -30px;
    border-right-color: white;
}

.timeline-date {
    position: absolute;
    left: 50%;
    top: 20px;
    transform: translateX(-50%);
    background: var(--primary-color);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-weight: 600;
    font-size: 0.9rem;
    z-index: 10;
}

.activity-type {
    display: inline-block;
    background: var(--gradient-secondary);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 15px;
    font-size: 0.8rem;
    font-weight: 500;
    margin-bottom: 1rem;
}

.activity-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 1rem;
}

.activity-description {
    color: var(--text-light);
    line-height: 1.6;
    margin-bottom: 1rem;
}

.activity-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 1rem;
    border-top: 1px solid #eee;
    font-size: 0.9rem;
    color: var(--text-light);
}

.activity-participants {
    display: flex;
    align-items: center;
}

.activity-participants i {
    margin-right: 0.5rem;
    color: var(--primary-color);
}

.upcoming-activities {
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    padding: 4rem 0;
}

.upcoming-card {
    background: white;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: 0 5px 20px rgba(0,0,0,0.1);
    transition: all 0.3s ease;
    margin-bottom: 2rem;
}

.upcoming-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 40px rgba(0,0,0,0.15);
}

.upcoming-header {
    background: var(--gradient-primary);
    color: white;
    padding: 1.5rem;
    text-align: center;
}

.upcoming-date {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.upcoming-month {
    font-size: 1rem;
    opacity: 0.9;
}

.upcoming-body {
    padding: 2rem;
}

.upcoming-title {
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 1rem;
}

.upcoming-details {
    color: var(--text-light);
    line-height: 1.6;
}

.register-btn {
    background: var(--gradient-secondary);
    border: none;
    color: white;
    padding: 0.75rem 2rem;
    border-radius: 25px;
    font-weight: 600;
    transition: all 0.3s ease;
    margin-top: 1rem;
}

.register-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(255, 107, 107, 0.3);
    color: white;
}

/* Responsive Design for Activities Page */
@media (max-width: 768px) {
    .activities-hero h1 {
        font-size: 2.5rem;
    }
    
    .activities-hero p {
        font-size: 1.1rem;
    }
    
    .activity-timeline::before {
        left: 20px;
    }
    
    .timeline-item:nth-child(odd) .timeline-content,
    .timeline-item:nth-child(even) .timeline-content {
        margin-left: 3rem;
        margin-right: 1rem;
    }
    
    .timeline-item:nth-child(odd) .timeline-content::before,
    .timeline-item:nth-child(even) .timeline-content::before {
        left: -30px;
        border-right-color: white;
        border-left-color: transparent;
    }
    
    .timeline-date {
        left: 20px;
        transform: none;
    }
    
    .activity-meta {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
    }
}

@media (max-width: 576px) {
    .activities-hero {
        padding: 60px 0;
    }
    
    .activities-hero h1 {
        font-size: 2rem;
    }
    
    .filter-btn {
        padding: 0.5rem 1rem;
        font-size: 0.9rem;
    }
    
    .timeline-content {
        padding: 1.5rem;
    }
    
    .upcoming-body {
        padding: 1.5rem;
    }
}

/* Added from activities.html */
/* 添加样式确保卡片高度一致 */
.card.h-100 {
    display: flex;
    flex-direction: column;
}

.card.h-100 .card-body {
    flex: 1;
    display: flex;
    flex-direction: column;
}

.card-text {
    flex-grow: 1;
    overflow: hidden;
}

/* 确保按钮始终在底部 */
.mt-auto {
    margin-top: auto !important;
}