/* 학습 자료실 섹션 */
.materials {
    padding: 1rem 0;
}

/* 필터 및 검색 */
.materials-filter {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 2rem;
    margin-bottom: 2rem;
    padding: 1.5rem;
    background: var(--white);
    border: 1.5px solid var(--black);
    border-radius: 12px;
}

.filter-group {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.filter-btn {
    padding: 0.5rem 1.25rem;
    border: 1px solid var(--black);
    background: var(--white);
    border-radius: 8px;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--black);
    cursor: pointer;
    transition: var(--transition);
}

.filter-btn:hover {
    background: var(--gray-light);
}

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

/* 검색 박스 */
.search-box {
    display: flex;
    gap: 0.5rem;
    min-width: 300px;
}

.search-input {
    flex: 1;
    padding: 0.75rem 1rem;
    border: 1.5px solid var(--black);
    border-radius: 8px;
    font-size: 0.875rem;
    font-family: 'Pretendard', sans-serif;
    transition: var(--transition);
}

.search-input:focus {
    outline: none;
}

.search-btn {
    font-size: 1rem;
    padding: 0.75rem 1.25rem;
    border: none;
    background: var(--black);
    color: var(--white);
    border-radius: 8px;
    cursor: pointer;
    transition: var(--transition);
}

.search-btn:hover {
    background: #334155;
}

/* 자료 목록 */
.materials-list {
    display: grid;
    gap: 1rem;
}

/* 자료 아이템 */
.material-item {
    display: flex;
    align-items: center;
    gap: 1.5rem;
    padding: 1.5rem;
    background: var(--white);
    border: 1.5px solid var(--black);
    border-radius: 12px;
    transition: var(--transition);
}

.material-item:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.material-item.hidden {
    display: none;
}

/* 자료 아이콘 */
.material-icon {
    width: 60px;
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gray-light);
    border-radius: 12px;
    font-size: 1.75rem;
    color: var(--black);
    flex-shrink: 0;
}

.material-icon .fa-file-pdf {
    color: #ef4444;
}

.material-icon .fa-file-word {
    color: #3b82f6;
}

/* 자료 정보 */
.material-info {
    flex: 1;
}

.material-header {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 0.5rem;
}

.material-title {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--black);
    margin: 0;
}

.material-badge {
    padding: 0.25rem 0.75rem;
    border-radius: 4px;
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--white);
}

.material-badge.korean {
    background: #8b5cf6;
}

.material-badge.english {
    background: #3b82f6;
}

.material-badge.math {
    background: #ef4444;
}

.material-badge.science {
    background: #10b981;
}

.material-badge.society {
    background: #f59e0b;
}

.material-desc {
    font-size: 0.875rem;
    color: var(--gray);
    margin: 0 0 0.75rem 0;
    line-height: 1.6;
}

.material-meta {
    display: flex;
    gap: 1.5rem;
    font-size: 0.8125rem;
    color: var(--gray);
}

.material-meta span {
    display: flex;
    align-items: center;
    gap: 0.375rem;
}

.material-meta i {
    font-size: 0.75rem;
}

/* 다운로드 버튼 */
.download-btn {
    padding: 0.75rem 1.5rem;
    border: 1px solid var(--black);
    background: var(--white);
    color: var(--black);
    border-radius: 8px;
    font-size: 0.875rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    white-space: nowrap;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.download-btn:hover {
    background: var(--black);
    color: var(--white);
}

/* 검색 결과 없음 */
.no-results {
    text-align: center;
    padding: 5rem 2rem;
    color: var(--gray);
}

.no-results i {
    font-size: 4rem;
    margin-bottom: 1rem;
    opacity: 0.3;
}

.no-results p {
    font-size: 1.125rem;
    margin: 0;
}

/* 반응형 */
@media (max-width: 1024px) {
    .materials-filter {
        flex-direction: column;
        align-items: stretch;
    }

    .search-box {
        min-width: auto;
    }
}

@media (max-width: 768px) {
    .materials-filter {
        padding: 1rem;
    }

    .filter-btn {
        padding: 0.5rem 1rem;
        font-size: 0.8125rem;
    }

    .search-box {
        flex-direction: column;
    }

    .search-btn {
        width: 100%;
    }

    .material-item {
        flex-direction: column;
        align-items: flex-start;
        padding: 1.25rem;
    }

    .material-icon {
        width: 50px;
        height: 50px;
        font-size: 1.5rem;
    }

    .material-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
    }

    .material-meta {
        flex-wrap: wrap;
        gap: 1rem;
    }

    .download-btn {
        width: 100%;
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .filter-group {
        gap: 0.375rem;
    }

    .filter-btn {
        padding: 0.5rem 0.75rem;
        font-size: 0.75rem;
    }

    .material-title {
        font-size: 1rem;
    }

    .material-desc {
        font-size: 0.8125rem;
    }

    .material-meta {
        font-size: 0.75rem;
        gap: 0.75rem;
    }
}