body {
    background-color: #f3f3f3;
    font-family: 'Segoe UI', sans-serif;
    margin: 0;
    padding: 20px;
}

.grid-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 15px;
}

.grid-item {
    background-color: #fff;
    border-radius: 6px;
    overflow: hidden;
    display: flex;
    justify-content: center;
    align-items: center;
    box-shadow: 0 1px 4px rgba(0,0,0,0.15);
}

.grid-item img,
.grid-item video {
    width: 100%;
    height: auto;
    display: block;
    object-fit: cover;
}