* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    padding: 20px;
    font-family: Arial, sans-serif;
}

.grid-demo {
    display: grid;
    grid-template-columns: 200px 1fr;
    grid-template-rows: 100px 1fr 60px;
    gap: 10px;
    min-height: 400px;
}

.box {
    display: flex;
    justify-content: center;
    align-items: center;
    color: white;
    font-weight: bold;
    border-radius: 8px;
    padding: 10px;
}

.box1 { background: #6C63FF; grid-column: 1 / -1; }
.box2 { background: #FF6584; }
.box3 { background: #00C9A7; }
.box4 { background: #3F3D56; grid-column: 1 / -1; }

@media (max-width: 768px) {
    .grid-demo {
        grid-template-columns: 1fr;
        grid-template-rows: auto;
    }
    
    .box {
        min-height: 80px;
    }
}