.lesson-group {
    margin-top: 1.8rem;
    margin-bottom: .4rem;

    font-size: 1.2rem;
    color: #444;
}

.lesson-separator {
    border: none;
    border-top: 2px solid #e6e6e6;
    margin-bottom: .8rem;
}

.lesson-grid {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: .8rem;
}

.lesson-button {

    display: block;
    width: 100%;

    margin: .45rem 0;
    padding: .8rem 1rem;

    font-size: 1rem;
}

.lesson-card {

    background: white;

    border: 2px solid #e8e8e8;
    border-radius: 16px;

    padding: 1rem;

    margin: .8rem 0;

    cursor: pointer;

    transition:
        transform .15s ease,
        box-shadow .15s ease;
}

.lesson-card:hover {

    transform: translateY(-3px);

    box-shadow: 0 8px 18px rgba(0,0,0,.08);

}

.lesson-card-title {

    margin: 0;

    font-size: 1.2rem;

}

.lesson-card-subtitle {

    margin-top: .4rem;

    color: #666;

    font-size: .95rem;

}

.lesson-type-badge {
    font-size: 1.4rem;
    margin-bottom: .3rem;
    text-align: center;
    display: block;
}

.lesson-stat-badge {
    display: block;
    margin-top: .4rem;
    font-size: .8rem;
    color: #888;
    text-align: right;
}

.category-section {
    margin-bottom: 1.5rem;
}

.category-title {
    font-size: 1rem;
    color: #666;
    margin-bottom: .5rem;
    padding-bottom: .3rem;
    border-bottom: 1px solid #eee;
}

.lesson-badges {
    display: flex;
    gap: .3rem;
    margin-bottom: .3rem;
}

.lesson-difficulty-badge {
    font-size: 1rem;
}

.filter-toggle-btn {
    display: block;
    margin: 0.5rem auto;
    padding: 0.5rem 1rem;
    font-size: 0.9rem;
    background: #f0f0f0;
    color: #333;
    border: 1px solid #ddd;
    border-radius: 8px;
    cursor: pointer;
}

.filter-toggle-btn:hover {
    background: #e0e0e0;
}

.filter-panel {
    display: none;
    flex-direction: column;
    gap: 0.5rem;
    padding: 0.8rem;
    background: #f8f8f8;
    border-radius: 12px;
    margin-bottom: 1rem;
}

.filter-row {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    flex-wrap: wrap;
}

.filter-label {
    font-size: 0.8rem;
    font-weight: 600;
    min-width: 70px;
    color: #555;
}

.filter-btn {
    display: inline-block;
    margin: 0;
    padding: 0.3rem 0.6rem;
    font-size: 0.75rem;
    border: 1px solid #bbb;
    border-radius: 6px;
    background: #888;
    color: white;
    cursor: pointer;
    transition: all 0.15s;
}

.filter-btn:hover {
    background: #777;
}

.filter-btn.active {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
}

.filter-skill-btns {
    display: flex;
    flex-wrap: wrap;
    gap: 0.3rem;
}

.filter-clear {
    margin-top: 0.3rem;
}

.filter-clear-btn {
    display: inline-block;
    margin: 0;
    padding: 0.3rem 0.6rem;
    font-size: 0.75rem;
    background: #ffcccc;
    color: #333;
    border: 1px solid #ff9999;
    border-radius: 6px;
    cursor: pointer;
}

.filter-clear-btn:hover {
    background: #ff9999;
}

.filter-result-info {
    font-size: 0.8rem;
    color: #666;
    text-align: center;
    margin-bottom: 0.5rem;
}