/* 탭 스타일 */
.cert-tabs { display: flex; justify-content: center; gap: 10px; margin-bottom: 60px; width:100%; }
.tab-item { padding: 12px 30px; font-size: 16px; font-weight: 500; border: 1px solid #ddd; background: #fff; color: #666; cursor: pointer; transition: 0.3s; border-radius: 4px; }
.tab-item:hover { background: #f8f8f8; }
.tab-item.active { background: #222; color: #fff; border-color: #222; }

/* 그리드 레이아웃 */
.cert-grid { width:100%; display: grid; grid-template-columns: repeat(4, 1fr); gap: 30px; }
.cert-card { text-align: center; }
.img-box { position: relative; width: 100%; aspect-ratio: 1 / 1.4; background: #f4f4f4; border: 1px solid #eee; overflow: hidden; margin-bottom: 15px; cursor: pointer; }
.img-box img { width: 100%; height: 100%; object-fit: cover; transition: 0.3s; }
.overlay { position: absolute; top: 0; left: 0; width: 100%; height: 100%; background: rgba(0,0,0,0.5); display: flex; justify-content: center; align-items: center; opacity: 0; transition: 0.3s; }
.overlay span { color: #fff; border: 1px solid #fff; padding: 8px 15px; font-size: 14px; }
.img-box:hover img { transform: scale(1.05); }
.img-box:hover .overlay { opacity: 1; }
.cert-name { font-size: 17px; font-weight: 500; color: #222; word-break: keep-all; line-height: 1.4; }

/* 반응형 */
@media (max-width: 1024px){
    .cert-grid { grid-template-columns: repeat(3, 1fr); }
}

@media (max-width: 768px){
    .cert-grid { grid-template-columns: repeat(2, 1fr); }
    .tab-item { padding: 10px 15px; font-size: 14px; }
}