.grid-demo {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}
.grid-demo .card {
    flex: 1 1 calc(33.333% - 10px);
    min-width: 150px;
    padding: 15px;
    border-radius: 8px;
    text-align: center;
}
.grid-demo .card:nth-of-type(3n+1) {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}
.grid-demo .card:nth-of-type(3n+2) {
    background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    color: white;
}
.grid-demo .card:nth-of-type(3n+3) {
    background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    color: white;
}