.activity-item {
    overflow: hidden;
    border: 1px solid var(--app-color-border);
    border-radius: var(--app-radius-lg);
    background: var(--app-color-surface-elevated);
    box-shadow: var(--app-shadow-md);
    transition:
        border-color 0.15s ease,
        box-shadow 0.15s ease;
}

.activity-item:hover {
    border-color: rgba(15, 118, 110, 0.2);
    box-shadow: var(--app-shadow-lg);
}

.activity-item .card-header {
    padding: 1rem 1.25rem;
    border-bottom: 1px solid var(--app-color-border);
    background: #f8fafc;
}

.activity-item .card-body {
    padding: 1.25rem;
}

.activity-item .activity-number {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 1.5rem;
    height: 1.5rem;
    margin-left: 0.25rem;
    padding: 0 0.4rem;
    border-radius: var(--app-radius-pill);
    background: var(--app-color-primary-soft);
    color: var(--app-color-primary);
    font-size: 0.75rem;
    font-weight: 700;
}

.activity-item .remove-activity:disabled {
    visibility: hidden;
}

.add-activity-bar {
    position: sticky;
    top: calc(var(--app-header-height) + 0.5rem);
    z-index: 1020;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    margin-bottom: 1rem;
    padding: 0.875rem 1rem;
    border: 1px solid var(--app-color-border);
    border-radius: var(--app-radius-md);
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(8px);
    box-shadow: var(--app-shadow-md);
}

.add-activity-bar__title {
    margin: 0;
    font-size: 1rem;
    font-weight: 700;
    letter-spacing: -0.01em;
}

#activities-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

#activities-list .activity-item {
    margin-bottom: 0;
}