.history-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 60px 20px;
}

/* 상단 헤더 */
.history-header {
    text-align: center;
    margin-bottom: 80px;
}

.history-title {
    font-size: 42px;
    font-weight: bold;
    color: #333;
    margin-bottom: 20px;
    letter-spacing: -0.5px;
}

.history-intro {
    font-size: 16px;
    color: #666;
    margin: 0;
}

/* 타임라인 */
.timeline {
    position: relative;
    padding: 20px 0;
}

/* 중앙 세로선 */
.timeline::before {
    content: '';
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 2px;
    background-color: #e0e0e0;
    transform: translateX(-50%);
}

/* 타임라인 섹션 */
.timeline-section {
    position: relative;
    margin-bottom: 100px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: start;
}

.timeline-section:last-child {
    margin-bottom: 0;
}

/* 타임라인 마커 (중앙 원) */
.timeline-marker {
    position: absolute;
    left: 50%;
    top: 30px;
    width: 20px;
    height: 20px;
    background-color: #FF8A3D;
    border: 4px solid #fff;
    border-radius: 50%;
    transform: translateX(-50%);
    box-shadow: 0 0 0 4px #e0e0e0;
    z-index: 2;
}

/* 타임라인 컨텐츠 */
.timeline-content {
    padding: 20px;
}

.timeline-content.left {
    text-align: right;
    padding-right: 40px;
}

.timeline-content.right {
    text-align: left;
    padding-left: 40px;
}

/* 연도 */
.timeline-year {
    font-size: 48px;
    font-weight: bold;
    color: #FF8A3D;
    margin-bottom: 20px;
    line-height: 1;
}

/* 설명 */
.timeline-desc {
    font-size: 18px;
    color: #555;
    line-height: 1.7;
    margin-bottom: 30px;
}

/* 이미지 */
.timeline-image {
    width: 100%;
    max-width: 500px;
    margin: 0 auto;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

.timeline-content.left .timeline-image {
    margin-left: auto;
    margin-right: 0;
}

.timeline-content.right .timeline-image {
    margin-left: 0;
    margin-right: auto;
}

.timeline-image img {
    width: 100%;
    height: auto;
    display: block;
    filter: grayscale(100%);
    transition: filter 0.3s ease;
}

.timeline-image:hover img {
    filter: grayscale(0%);
}

/* 이벤트 목록 */
.timeline-events {
    list-style: none;
    padding: 0;
    margin: 0;
}

.timeline-events li {
    padding: 15px 0;
    border-bottom: 1px solid #f0f0f0;
    display: flex;
    align-items: flex-start;
    gap: 20px;
}

.timeline-events li:last-child {
    border-bottom: none;
}

.timeline-content.left .timeline-events li {
    flex-direction: row-reverse;
    text-align: right;
}

.timeline-content.right .timeline-events li {
    flex-direction: row;
    text-align: left;
}

.event-date {
    font-size: 14px;
    font-weight: 600;
    color: #FF8A3D;
    white-space: nowrap;
    min-width: 80px;
}

.event-text {
    font-size: 15px;
    color: #555;
    line-height: 1.6;
}

/* 태블릿 */
@media (max-width: 992px) {
    .history-container {
        padding: 40px 20px;
    }
    
    .history-title {
        font-size: 36px;
    }
    
    .history-header {
        margin-bottom: 60px;
    }
    
    .timeline-section {
        gap: 40px;
    }
    
    .timeline-year {
        font-size: 40px;
    }
    
    .timeline-desc {
        font-size: 16px;
    }
    
    .timeline-content.left {
        padding-right: 30px;
    }
    
    .timeline-content.right {
        padding-left: 30px;
    }
}

/* 모바일 */
@media (max-width: 768px) {
    .history-container {
        padding: 30px 15px;
    }
    
    .history-title {
        font-size: 28px;
        margin-bottom: 15px;
    }
    
    .history-intro {
        font-size: 14px;
    }
    
    .history-header {
        margin-bottom: 40px;
    }
    
    /* 타임라인을 좌측으로 이동 */
    .timeline::before {
        left: 30px;
    }
    
    .timeline-section {
        display: block;
        margin-bottom: 60px;
        padding-left: 60px;
    }
    
    .timeline-marker {
        left: 30px;
        top: 0;
        width: 16px;
        height: 16px;
        border-width: 3px;
    }
    
    .timeline-content {
        padding: 0;
        text-align: left !important;
        margin-bottom: 30px;
    }
    
    .timeline-content.left,
    .timeline-content.right {
        padding: 0;
    }
    
    .timeline-year {
        font-size: 32px;
        margin-bottom: 15px;
    }
    
    .timeline-desc {
        font-size: 15px;
        margin-bottom: 20px;
    }
    
    .timeline-desc br {
        display: none;
    }
    
    .timeline-image {
        max-width: 100%;
        margin: 0 !important;
    }
    
    .timeline-events li {
        flex-direction: column !important;
        text-align: left !important;
        gap: 5px;
        padding: 12px 0;
    }
    
    .event-date {
        font-size: 13px;
        min-width: auto;
    }
    
    .event-text {
        font-size: 14px;
    }
}

/* 인증서 섹션 */
.certificates-section {
    margin-top: 100px;
    text-align: center;
}

.certificates-title {
    font-size: 36px;
    font-weight: bold;
    color: #333;
    margin-bottom: 15px;
}

.certificates-intro {
    font-size: 16px;
    color: #666;
    margin-bottom: 50px;
}

.certificates-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 30px;
    max-width: 1200px;
    margin: 0 auto;
}

.certificate-card {
    background: #fff;
    border-radius: 16px;
    padding: 40px 20px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
    transition: all 0.3s ease;
    cursor: pointer;
    position: relative;
    overflow: hidden;
}

.certificate-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 5px;
    background: linear-gradient(90deg, #FF8A3D, #FF6B35);
}

.certificate-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 8px 30px rgba(255, 107, 53, 0.2);
}

.certificate-icon {
    font-size: 48px;
    margin-bottom: 20px;
}

.certificate-name {
    font-size: 20px;
    font-weight: bold;
    color: #333;
    margin: 0 0 15px 0;
}

.certificate-desc {
    font-size: 14px;
    color: #666;
    line-height: 1.6;
    margin: 0 0 20px 0;
}

.certificate-view {
    display: inline-block;
    padding: 8px 20px;
    background: linear-gradient(135deg, #FF8A3D, #FF6B35);
    color: #fff;
    border-radius: 20px;
    font-size: 13px;
    font-weight: 600;
}

/* 인증서 레이어 팝업 */
.certificate-modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 9999;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.certificate-modal .modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.8);
    backdrop-filter: blur(4px);
}

.certificate-modal .modal-content {
    position: relative;
    background: #fff;
    border-radius: 20px;
    max-width: 800px;
    width: 100%;
    max-height: 90vh;
    display: flex;
    flex-direction: column;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
    z-index: 10000;
    animation: modalSlideUp 0.3s ease;
}

@keyframes modalSlideUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.certificate-modal .modal-close {
    position: absolute;
    top: 20px;
    right: 20px;
    width: 40px;
    height: 40px;
    border: none;
    background: rgba(0,0,0,0.5);
    border-radius: 50%;
    font-size: 28px;
    line-height: 1;
    color: #fff;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1;
}

.certificate-modal .modal-close:hover {
    background: #FF6B35;
    transform: rotate(90deg);
}

.certificate-modal .modal-body {
    padding: 30px;
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.cert-modal-title {
    font-size: 24px;
    font-weight: bold;
    color: #333;
    text-align: center;
    margin: 0 0 20px 0;
    padding-bottom: 15px;
    border-bottom: 3px solid #FF8A3D;
    flex-shrink: 0;
}

.cert-image-wrapper {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.cert-image {
    max-width: 100%;
    max-height: calc(90vh - 150px);
    width: auto;
    height: auto;
    object-fit: contain;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

/* 태블릿 */
@media (max-width: 992px) {
    .certificates-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 25px;
    }
    
    .certificates-title {
        font-size: 32px;
    }
}

/* 모바일 */
@media (max-width: 768px) {
    .certificates-section {
        margin-top: 60px;
    }
    
    .certificates-title {
        font-size: 26px;
        margin-bottom: 12px;
    }
    
    .certificates-intro {
        font-size: 14px;
        margin-bottom: 30px;
    }
    
    .certificates-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 20px;
    }
    
    .certificate-card {
        padding: 30px 15px;
    }
    
    .certificate-icon {
        font-size: 40px;
        margin-bottom: 15px;
    }
    
    .certificate-name {
        font-size: 17px;
        margin-bottom: 10px;
    }
    
    .certificate-desc {
        font-size: 13px;
        margin-bottom: 15px;
    }
    
    .certificate-view {
        font-size: 12px;
        padding: 6px 16px;
    }
    
    .certificate-modal .modal-body {
        padding: 20px 15px;
    }
    
    .cert-modal-title {
        font-size: 20px;
        margin-bottom: 15px;
        padding-bottom: 12px;
    }
    
    .cert-image {
        max-height: calc(90vh - 120px);
    }
}

/* 작은 모바일 */
@media (max-width: 480px) {
    .history-container {
        padding: 20px 10px;
    }
    
    .history-title {
        font-size: 24px;
    }
    
    .history-intro {
        font-size: 13px;
    }
    
    .timeline-section {
        padding-left: 50px;
    }
    
    .timeline::before {
        left: 25px;
    }
    
    .timeline-marker {
        left: 25px;
        width: 14px;
        height: 14px;
    }
    
    .timeline-year {
        font-size: 28px;
    }
    
    .timeline-desc {
        font-size: 14px;
    }
}