body {
    font-family: sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background-color: #282c34;
    color: #fff;
    margin: 0;
}

#app {
    background-color: #3a404b;
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
    text-align: center;
    max-width: 500px;
    width: 90%;
}

header {
    margin-bottom: 20px;
}

h1 {
    color: #61dafb;
}

.lang-selector button {
    background-color: #61dafb;
    border: none;
    padding: 8px 12px;
    margin: 0 5px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 0.9em;
    color: #282c34;
}

.lang-selector button.active {
    background-color: #007bff;
    color: #fff;
}

#question-area p {
    font-size: 1.1em;
    margin-bottom: 5px;
}

.hand-display {
    font-size: 2em;
    font-weight: bold;
    margin-bottom: 20px;
    min-height: 1.5em; /* 高さを確保 */
}

#action-buttons button {
    background-color: #4CAF50;
    color: white;
    padding: 12px 20px;
    margin: 5px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 1em;
    width: calc(50% - 10px); /* 2列配置 */
    box-sizing: border-box;
}

#action-buttons button:hover {
    opacity: 0.9;
}

#feedback-area {
    margin-top: 20px;
    min-height: 60px; /* 高さを確保 */
}

#result-message {
    font-size: 1.2em;
    font-weight: bold;
    margin-bottom: 10px;
}

#next-btn {
    background-color: #007bff;
    color: white;
    padding: 10px 15px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 1em;
    display: none; /* デフォルトは非表示 */
}

#next-btn:hover {
    opacity: 0.9;
}

#stats-area {
    margin-top: 20px;
    border-top: 1px solid #4a505c;
    padding-top: 15px;
    font-size: 0.9em;
}