.activity-card {
    background: #fff;
    border: 1px solid #eaeaea;
    border-radius: 4px;
    padding: 40px 30px;
    margin-bottom: 40px;
    text-align: left;
    position: relative;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.02);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.activity-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.05);
}

.activity-num {
    font-size: 0.8rem;
    color: #888;
    letter-spacing: 0.2em;
    margin-bottom: 8px;
    display: block;
}

.activity-title {
    font-size: 1.4rem;
    font-weight: 600;
    margin-bottom: 20px;
    color: #111;
    border-bottom: 1px solid #eee;
    padding-bottom: 12px;
}

.activity-desc {
    font-size: 0.95rem;
    line-height: 2.1;
    color: #444;
}

.device-badge {
    display: inline-block;
    background: #111;
    color: #fff;
    font-size: 0.75rem;
    padding: 4px 12px;
    letter-spacing: 0.1em;
    margin-bottom: 12px;
    border-radius: 2px;
}