.aviation-header {
    text-align: center;
    padding: 3rem 0;
    background-color: var(--white);
    border-radius: var(--border-radius);
    margin-bottom: 2rem;
    box-shadow: var(--shadow);
    position: relative;
    overflow: hidden;
}

.aviation-header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 5px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
}

.aviation-header h2 {
    font-size: 2.5rem;
    color: var(--dark-color);
    margin-bottom: 1rem;
    position: relative;
    display: inline-block;
}

.aviation-header h2::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 3px;
    background-color: var(--primary-color);
}

.aviation-header p {
    font-size: 1.2rem;
    color: var(--gray-color);
    max-width: 800px;
    margin: 0 auto;
}

.learning-materials {
    display: grid;
    gap: 2rem;
}

.material-card {
    background-color: var(--white);
    border-radius: var(--border-radius);
    padding: 2rem;
    box-shadow: var(--shadow);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
    border: 1px solid rgba(0,0,0,0.05);
}

.material-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0,0,0,0.1);
}

.material-card h3 {
    color: var(--dark-color);
    margin-bottom: 1.5rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--primary-color);
    position: relative;
    display: inline-block;
}

.material-card h3::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 50px;
    height: 2px;
    background-color: var(--secondary-color);
    transition: var(--transition);
}

.material-card:hover h3::after {
    width: 100%;
}

.material-content {
    display: grid;
    gap: 1.5rem;
}

.material-item {
    display: flex;
    align-items: flex-start;
    padding: 1.5rem;
    background-color: var(--light-color);
    border-radius: 8px;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border: 1px solid rgba(0,0,0,0.05);
    position: relative;
    overflow: hidden;
    will-change: transform;
}

.material-item::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background-color: var(--primary-color);
    transition: var(--transition);
}

.material-item:hover {
    transform: translateX(10px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.material-item:hover::before {
    background-color: var(--secondary-color);
}

.material-icon {
    font-size: 2.5rem;
    color: var(--secondary-color);
    margin-right: 1.5rem;
    transition: var(--transition);
}

.material-item:hover .material-icon {
    transform: scale(1.1);
}

.material-info {
    flex: 1;
}

.material-info h4 {
    color: var(--dark-color);
    margin-bottom: 0.5rem;
    font-size: 1.2rem;
    position: relative;
    display: inline-block;
}

.material-info h4::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--primary-color);
    transition: var(--transition);
}

.material-item:hover .material-info h4::after {
    width: 100%;
}

.material-info p {
    color: var(--gray-color);
    margin-bottom: 1rem;
    font-size: 0.95rem;
}

.access-btn {
    display: inline-flex;
    align-items: center;
    background-color: var(--primary-color);
    color: var(--white);
    text-decoration: none;
    padding: 0.5rem 1rem;
    border-radius: 5px;
    transition: var(--transition);
    font-weight: 500;
    position: relative;
    overflow: hidden;
    z-index: 1;
}

.access-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
    transition: var(--transition);
    z-index: -1;
}

.access-btn:hover::before {
    left: 100%;
}

.access-btn i {
    margin-right: 0.5rem;
    transition: var(--transition);
}

.access-btn:hover {
    background-color: var(--dark-color);
    transform: translateY(-2px);
}

.access-btn:hover i {
    transform: translateY(-2px);
}

/* Основные стили */
.english-content {
    max-width: 100%;
    margin: 0 auto;
    padding: 1.5rem;
}

/* Секция введения */
.intro-section {
    background: white;
    border-radius: 12px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    box-shadow: 0 3px 10px rgba(0, 0, 0, 0.1);
}

.intro-section h3 {
    color: var(--primary-color);
    margin-bottom: 0.8rem;
    display: flex;
    align-items: center;
    gap: 0.4rem;
    font-size: 1.2rem;
}

.intro-section p {
    color: var(--dark-color);
    line-height: 1.5;
    margin-bottom: 1.2rem;
    font-size: 0.9rem;
}

/* Секция с темами для обсуждения */
.discussion-topics-section {
    background-color: var(--white);
    border-radius: 15px;
    padding: 2.5rem 2rem;
    margin: 2rem 0;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    position: relative;
    overflow: hidden;
}

.discussion-topics-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 5px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
}

.discussion-topics-section h2 {
    color: var(--dark-color);
    text-align: center;
    margin-bottom: 1.5rem;
    position: relative;
    padding-bottom: 0.5rem;
    font-size: 1.3rem;
    font-weight: 600;
}

.discussion-topics-section h3 {
    color: var(--dark-color);
    text-align: center;
    margin-bottom: 1.5rem;
    font-size: 1rem;
    font-weight: 400;
}

.topics-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 0.8rem;
    max-width: 1300px;
    margin: 0 auto;
}

.topic-button {
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--light-color);
    border: 1px solid rgba(0, 0, 0, 0.05);
    border-radius: 10px;
    text-decoration: none;
    color: #000000;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
    padding: 0.8rem;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.05);
    height: 60px;
}

.topic-button::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: linear-gradient(to bottom, var(--primary-color), var(--secondary-color));
    transition: width 0.3s ease;
}

.topic-button:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 15px rgba(0, 0, 0, 0.1);
    border-color: var(--primary-color);
}

.topic-button:hover::before {
    width: 6px;
}

.topic-button::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background: linear-gradient(to right, var(--primary-color), var(--secondary-color));
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.3s ease;
}

.topic-button:hover::after {
    transform: scaleX(1);
}

.topic-button span {
    font-size: 0.65rem;
    font-weight: 500;
    text-align: center;
    line-height: 1.3;
    position: relative;
    z-index: 1;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    max-width: 100%;
    padding: 0 5px;
}

/* Медиа-запросы для адаптивности */
@media (max-width: 768px) {
    .material-item {
        flex-direction: column;
        text-align: center;
    }

    .material-icon {
        margin: 0 0 1rem 0;
    }

    .access-btn {
        width: 100%;
        justify-content: center;
    }
    
    .material-item:hover {
        transform: translateY(-5px);
    }

    .discussion-topics-section {
        padding: 1.5rem 1rem;
    }
    
    .topics-container {
        grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
        gap: 0.8rem;
    }
    
    .topic-button {
        height: 60px;
        padding: 0.8rem;
    }
    
    .topic-button span {
        font-size: 0.7rem;
    }

    .audio-list {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .topics-container {
        grid-template-columns: 1fr;
    }
}

/* Учебные материалы */
.learning-materials {
    margin: 1.5rem 0;
}

.learning-materials h3 {
    color: var(--primary-color);
    margin-bottom: 1.2rem;
    display: flex;
    align-items: center;
    gap: 0.4rem;
    font-size: 1.2rem;
}

.materials-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1.2rem;
}

.material-card {
    background: white;
    border-radius: 8px;
    padding: 1.2rem;
    box-shadow: 0 3px 10px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
    text-align: center;
}

.material-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.15);
}

.material-card i {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 0.8rem;
}

.material-card h4 {
    color: var(--dark-color);
    margin-bottom: 0.4rem;
    font-size: 1rem;
}

.material-card p {
    color: var(--gray-color);
    margin-bottom: 0.8rem;
    font-size: 0.85rem;
}

.download-link {
    display: inline-block;
    padding: 0.4rem 0.8rem;
    background: var(--primary-color);
    color: white;
    text-decoration: none;
    border-radius: 4px;
    transition: background 0.3s ease;
    font-size: 0.85rem;
}

.download-link:hover {
    background: var(--primary-dark);
}

/* Секция практики */
.practice-section {
    background-color: var(--white-color);
    border-radius: var(--border-radius);
    padding: 2.5rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow);
    position: relative;
    overflow: hidden;
}

.practice-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 5px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
}

.practice-section h2 {
    color: var(--primary-color);
    text-align: center;
    margin-bottom: 1.5rem;
    position: relative;
    padding-bottom: 0.5rem;
    font-size: 1.8rem;
    font-weight: 600;
}

.practice-section h2::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 3px;
    background: linear-gradient(to right, var(--primary-color), var(--secondary-color));
}

.section-intro {
    background-color: rgba(52, 152, 219, 0.05);
    padding: 1.5rem;
    border-radius: 10px;
    margin-bottom: 1.5rem;
    border-left: 4px solid var(--primary-color);
}

.section-intro p {
    color: var(--dark-color);
    line-height: 1.6;
    margin: 0;
    font-size: 0.95rem;
}

.audio-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
    margin-top: 1.5rem;
    will-change: transform;
}

.audio-item {
    background: white;
    border-radius: 12px;
    padding: 1.2rem;
    box-shadow: 0 2px 8px rgba(0,0,0,0.08);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    will-change: transform;
}

.audio-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

.audio-item h5 {
    margin-bottom: 1rem;
    font-size: 1.1rem;
    color: var(--primary-color);
}

.audio-item audio {
    width: 100%;
    margin-top: 0.5rem;
}

/* Оптимизация для мобильных устройств */
@media (max-width: 768px) {
    .audio-container {
        grid-template-columns: 1fr;
    }
    
    .load-more-btn {
        width: 100%;
        max-width: 300px;
    }
}

/* Стили для свернутых разделов */
.audio-list.collapsed {
    display: none;
}

.audio-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.8rem;
    background-color: var(--light-color);
    border-radius: 10px;
    margin-bottom: 1rem;
    cursor: pointer;
    transition: background-color 0.3s ease;
    border-left: 4px solid var(--primary-color);
}

.audio-header:hover {
    background-color: rgba(52, 152, 219, 0.1);
}

.audio-header h3 {
    color: var(--primary-color);
    font-size: 1.1rem;
    font-weight: 600;
    margin: 0;
}

.toggle-btn {
    background: none;
    border: none;
    color: var(--primary-color);
    cursor: pointer;
    padding: 0.5rem;
    transition: transform 0.3s ease;
    width: 30px;
    height: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
}

.toggle-btn:hover {
    background-color: rgba(52, 152, 219, 0.1);
}

.toggle-btn.active {
    transform: rotate(180deg);
}

.toggle-btn i {
    font-size: 1rem;
}

/* Стили для кнопки "Загрузить еще" */
.load-more-btn {
    display: block;
    width: 100%;
    max-width: 300px;
    margin: 20px auto;
    padding: 12px 24px;
    background-color: #2c3e50;
    color: white;
    border: none;
    border-radius: 6px;
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
}

.load-more-btn:hover {
    background-color: #34495e;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.load-more-btn i {
    margin-left: 8px;
    transition: transform 0.3s ease;
}

.load-more-btn:hover i {
    transform: translateY(2px);
}

.english-content-header {
    text-align: center;
    margin-bottom: 2rem;
    color: #000000;
}

.english-content-header h1 {
    font-size: 1.8rem;
    margin-bottom: 1rem;
    color: #000000;
    font-weight: 600;
}

.english-content-header p {
    font-size: 1rem;
    color: #000000;
    max-width: 800px;
    margin: 0 auto;
    line-height: 1.5;
}

/* Адаптивность для заголовка */
@media screen and (max-width: 991px) {
    .english-content-header h1 {
        font-size: 1.6rem;
    }
    
    .english-content-header p {
        font-size: 0.95rem;
    }
}

@media screen and (max-width: 575px) {
    .english-content-header h1 {
        font-size: 1.4rem;
    }
    
    .english-content-header p {
        font-size: 0.9rem;
    }
}

/* Добавляем стили для audio-list */
.audio-list {
    display: grid;
    gap: 1rem;
    margin-top: 1rem;
}

.audio-list.collapsed {
    display: none;
}

/* Добавляем стили для topic-button i */
.topic-button i {
    font-size: 1.2rem;
    margin-right: 0.5rem;
    color: var(--primary-color);
}

@media (max-width: 768px) {
    .audio-header {
        padding: 0.6rem;
    }

    .audio-header h3 {
        font-size: 1rem;
    }

    .toggle-btn {
        width: 25px;
        height: 25px;
        padding: 0.4rem;
    }
}

@media (max-width: 480px) {
    .audio-header {
        padding: 0.5rem;
    }

    .audio-header h3 {
        font-size: 0.9rem;
    }

    .toggle-btn {
        width: 22px;
        height: 22px;
        padding: 0.3rem;
    }
}

.audio-description {
    color: #000000;
    margin-bottom: 20px;
}

.etian-test-section {
    padding: 2rem;
    background-color: #f8f9fa;
    border-radius: 10px;
    margin-bottom: 2rem;
}

.etian-test-container {
    display: flex;
    gap: 2rem;
    margin-top: 1.5rem;
}

.etian-test-text {
    flex: 1;
    padding-right: 2rem;
    border-right: 1px solid #dee2e6;
}

.etian-test-text h3 {
    margin-bottom: 1rem;
    font-size: 1.1rem;
    color: #333;
    line-height: 1.4;
}

.etian-test-buttons {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
    min-width: 400px;
}

.etian-test-buttons .topics-container {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    width: 100%;
}

.etian-test-buttons .topic-button {
    width: 100%;
    height: auto;
    padding: 1.2rem;
    min-height: 60px;
    display: flex;
    align-items: center;
    background: var(--light-color);
    border: 1px solid rgba(0, 0, 0, 0.05);
    border-radius: 10px;
    text-decoration: none;
    color: #000000;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.05);
}

.etian-test-buttons .topic-button i {
    font-size: 1.2rem;
    margin-right: 1rem;
    color: var(--primary-color);
}

.etian-test-buttons .topic-button span {
    font-size: 1rem;
    white-space: normal;
    text-align: left;
    padding: 0 1rem;
    flex: 1;
}

.etian-test-buttons .topic-button:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 15px rgba(0, 0, 0, 0.1);
    border-color: var(--primary-color);
}

@media (max-width: 768px) {
    .etian-test-container {
        flex-direction: column;
    }
    
    .etian-test-text {
        padding-right: 0;
        border-right: none;
        border-bottom: 1px solid #dee2e6;
        padding-bottom: 1.5rem;
        margin-bottom: 1.5rem;
    }

    .etian-test-buttons {
        min-width: 100%;
    }
}