body {
    font-family: sans-serif;
    display: flex;
    flex-direction: column;
    align-items: center;
    background-color: #f0f0f0;
    margin: 0;
    padding: 20px;
}

h1 {
    color: #333;
    margin-bottom: 20px;
}

.game-container {
    display: flex;
    gap: 20px;
    background-color: #fff;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}

#game-board {
    display: grid;
    /* 10列 x 20行のグリッドを想定 */
    grid-template-columns: repeat(10, 30px);
    grid-template-rows: repeat(20, 30px);
    border: 3px solid #333;
    background-color: #000;
}

.cell {
    width: 30px;
    height: 30px;
    box-sizing: border-box;
    border: 1px solid #111;
}

/* ピースの色 */
.i { background-color: cyan; border-color: #00ffff; }
.j { background-color: blue; border-color: #0000ff; }
.l { background-color: orange; border-color: #ffa500; }
.o { background-color: yellow; border-color: #ffff00; }
.s { background-color: lime; border-color: #00ff00; }
.t { background-color: purple; border-color: #800080; }
.z { background-color: red; border-color: #ff0000; }

.info-panel {
    width: 150px;
    padding: 10px;
    background-color: #eee;
    border-radius: 4px;
}

.info-panel h2 {
    margin-top: 0;
    border-bottom: 2px solid #ccc;
    padding-bottom: 5px;
}

#score {
    font-size: 2em;
    font-weight: bold;
    color: #007bff;
    margin-bottom: 20px;
}

.controls {
    font-size: 0.9em;
    line-height: 1.5;
    /*white-space: pre-wrap;*/
}

#game-over-message {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background-color: rgba(0, 0, 0, 0.8);
    color: white;
    padding: 30px;
    border-radius: 10px;
    text-align: center;
    z-index: 10;
}

#game-over-message h2 {
    color: red;
    font-size: 2.5em;
    margin-top: 0;
}

.hidden {
    display: none;
}