/* --- 核心变量继承与组件扩展 --- */
.activities-hero {
    height: 40vh;
    background: linear-gradient(rgba(0, 51, 102, 0.8), rgba(0, 51, 102, 0.8)), 
                url('https://news.sicau.edu.cn/__local/E/AF/CD/D6EBE48805F99B890F02A093BC9_1892809A_21A21.jpg') center/cover;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    color: white;
    margin-bottom: 0;
    clip-path: polygon(0 0, 100% 0, 100% 85%, 0 100%);
}

.activities-hero h1 {
    font-size: 3.5rem;
    margin-bottom: 1rem;
    text-shadow: 0 4px 15px rgba(0,0,0,0.3);
}

.activities-wrapper {
    display: grid;
    grid-template-columns: 2.8fr 1.2fr;
    gap: 3rem;
    margin-top: 3rem;
}

/* 侧边日历样式 */
.calendar-card {
    background: var(--bg-card);
    border-radius: 12px;
    padding: 1.5rem;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
    position: sticky;
    top: 100px;
}

.calendar-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
    padding-bottom: 1rem;
    border-bottom: 2px solid var(--primary-color);
}

.activity-day-item {
    display: flex;
    gap: 1.5rem;
    margin-bottom: 1.25rem;
    padding-bottom: 1.25rem;
    border-bottom: 1px dashed var(--border-color);
}

.activity-day-item:last-child {
    border-bottom: none;
}

.date-box {
    background: var(--primary-color);
    color: white;
    min-width: 55px;
    height: 65px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    border-radius: 8px;
    line-height: 1.2;
}

.date-box .day { font-size: 1.5rem; font-weight: bold; }
.date-box .month { font-size: 0.75rem; opacity: 0.9; }

/* 筛选条美化 */
.filter-bar {
    display: flex !important;
    gap: 1.5rem !important;
    flex-wrap: wrap !important;
    background: white !important;
    padding: 1.5rem !important;
    border-radius: 12px !important;
    margin-bottom: 2rem !important;
    box-shadow: var(--shadow-sm) !important;
}

.filter-group {
    display: flex !important;
    flex-direction: column !important;
    gap: 0.5rem !important;
    flex: 1 !important;
    min-width: 150px !important;
}

.filter-group label {
    font-size: 0.85rem !important;
    font-weight: bold !important;
    color: var(--text-muted) !important;
    margin-bottom: 0 !important;
}

/* 活动卡片升级 */
.activities-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 2.5rem;
}

.activity-card {
    background: white !important;
    border-radius: 15px !important;
    overflow: hidden !important;
    transition: var(--transition-base) !important;
    box-shadow: var(--shadow-sm) !important;
    display: flex !important;
    flex-direction: column !important;
    border: none !important;
    padding-bottom: 0 !important;
    position: relative !important;
}

.activity-card::before {
    content: '';
    position: absolute;
    top: -30%;
    left: 0;
    right: 0;
    height: 80%;
    background: url('/frontend/assets/uploads/beijing.webp') center/cover no-repeat;
    opacity: 0.15;
    pointer-events: none;
    z-index: 0;
    mask-image: linear-gradient(to bottom, rgba(0,0,0,0) 0%, rgba(0,0,0,1) 30%, rgba(0,0,0,1) 60%, rgba(0,0,0,0) 100%);
    -webkit-mask-image: linear-gradient(to bottom, rgba(0,0,0,0) 0%, rgba(0,0,0,1) 30%, rgba(0,0,0,1) 60%, rgba(0,0,0,0) 100%);
}

.activity-card > * {
    position: relative;
    z-index: 1;
}

.activity-card:hover {
    transform: translateY(-8px) !important;
    box-shadow: var(--shadow-md) !important;
}

.card-img {
    height: 220px !important;
    position: relative !important;
    overflow: hidden !important;
    border-radius: 0 !important;
    margin-bottom: 0 !important;
}

.card-img img {
    width: 100% !important;
    height: 100% !important;
    object-fit: cover !important;
    transition: transform 0.5s ease !important;
}

.activity-card:hover .card-img img {
    transform: scale(1.08) !important;
}

.status-badge {
    position: absolute !important;
    top: 15px !important;
    right: 15px !important;
    padding: 0.4rem 1rem !important;
    border-radius: 20px !important;
    font-size: 0.8rem !important;
    font-weight: bold !important;
    z-index: 2 !important;
    background: rgba(0,0,0,0.6) !important;
    color: white !important;
    backdrop-filter: blur(4px) !important;
}

.status-ongoing { background: #16803c !important; color: #fff !important; }
.status-upcoming { background: #2563eb !important; color: #fff !important; }
.status-full { background: #c2410c !important; color: #fff !important; }
.status-completed, .status-finished, .status-ended { background: #b91c1c !important; color: #fff !important; }

.card-content {
    padding: 1.5rem !important;
    flex-grow: 1 !important;
}

.card-content h3 {
    margin: 0 0 1rem 0 !important;
    color: var(--primary-color) !important;
    font-size: 1.25rem !important;
    line-height: 1.4 !important;
}

.meta-info {
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-bottom: 0.6rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.card-footer {
    padding: 1.25rem 1.5rem;
    border-top: 1px solid var(--border-color);
    background: var(--bg-light);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

@media (max-width: 768px) {
    .activities-wrapper {
        grid-template-columns: 1fr;
    }
    .activities-hero h1 { font-size: 2.5rem; }
}


.activity-card .card-content p {
    font-size: 0.95rem;
    color: var(--text-muted);
    margin-bottom: 0.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.sidebar .widget {
    margin-bottom: var(--space-xl);
}

.sidebar h3 {
    font-size: 1.25rem;
    margin-bottom: 1.5rem;
    color: var(--text-main);
    position: relative;
    padding-bottom: 1rem;
}

.sidebar h3::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 30px;
    height: 2px;
    background: var(--primary-color);
}

.calendar-view {
    background: var(--bg-section);
    padding: 1.5rem;
    border-radius: 4px;
    text-align: center;
}

.stat-item {
    display: flex;
    justify-content: space-between;
    padding: 1.25rem 0;
    border-bottom: 1px dotted var(--border-color);
}

.stat-label { color: var(--text-muted); font-size: 0.95rem; }
.stat-value { font-weight: 700; color: var(--primary-color); font-size: 1.1rem; }

@media (max-width: 992px) {
    .activities-wrapper {
        grid-template-columns: 1fr;
    }
}