body {
    font-family: Arial, sans-serif;
    margin: 0;
    background-color: #f4f4f4;
    color: #333;
    text-align: center;
}

header {
    background-color: #222;
    color: white;
    padding: 30px;
}

.section {
    padding: 40px;
}

video {
    width: 70%;
    max-width: 700px;
    border-radius: 10px;
}

.cert-container {
    display: flex;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
}

.cert-container img {
    width: 250px;
    border-radius: 10px;
    box-shadow: 0 5px 10px rgba(0,0,0,0.2);
}

footer {
    background-color: #222;
    color: white;
    padding: 15px;
}

/* Certificate hover */
.cert-container img {
    cursor: pointer;
    transition: transform 0.3s;
}

.cert-container img:hover {
    transform: scale(1.05);
}

/* Modal (Lightbox) */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0,0,0,0.9);
    justify-content: center;
    align-items: center;
}

.modal-content {
    max-width: 90%;
    max-height: 90%;
    border-radius: 10px;
}

.close {
    position: absolute;
    top: 20px;
    right: 35px;
    color: white;
    font-size: 40px;
    cursor: pointer;
}

/* Certificate Group */
.certificate-group {
    margin-top: 40px;
}

.certificate-group h3 {
    text-align: left;
    max-width: 900px;
    margin: 0 auto 20px;
    color: #222;
    font-size: 20px;
}

/* Certificate container */
.cert-container {
    display: flex;
    justify-content: center;
    gap: 25px;
    flex-wrap: wrap;
}

.cert-container img {
    width: 260px;
    border-radius: 12px;
    cursor: pointer;
    box-shadow: 0 6px 12px rgba(0,0,0,0.15);
    transition: transform 0.3s, box-shadow 0.3s;
}

.cert-container img:hover {
    transform: scale(1.05);
    box-shadow: 0 10px 18px rgba(0,0,0,0.25);
}