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

body {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background-color: #f0f0f0;
    touch-action: none;
}

.container {
    display: flex;
    flex-direction: row;
    gap: 20px;
    padding: 20px;
    background-color: white;
    border-radius: 15px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.item {
    width: 80px;
    height: 80px;
    display: flex;
    justify-content: center;
    align-items: center;
    background-color: #fff;
    border: 2px solid #ddd;
    border-radius: 10px;
    font-size: 40px;
    cursor: pointer;
    user-select: none;
    touch-action: none;
    position: relative;
    will-change: transform;
    transform: translate3d(0, 0, 0);
}

.item.dragging {
    z-index: 1000;
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.15);
    border-color: #2196F3;
    pointer-events: none;
}

.item.target-indicator {
    border-color: #4CAF50;
    background-color: rgba(76, 175, 80, 0.1);
}