body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: #f0f2f5;
    color: #333;
    display: flex;
    flex-direction: column;
    align-items: center;
    margin: 0;
    padding: 20px;
}

h1 {
    color: #1a1a1a;
    margin-bottom: 15px;
}

/* コントロールパネルのスタイル */
#controls {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    background-color: #fff;
    padding: 15px 25px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    margin-bottom: 20px;
    align-items: center;
    justify-content: center;
}
 
.control-group {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 0.95em;
}

select, input[type="range"], input[type="number"] {
    cursor: pointer;
    padding: 4px;
    border: 1px solid #ccc;
    border-radius: 4px;
}

#stats {
    display: flex;
    gap: 24px;
    font-size: 1.2em;
    margin-bottom: 20px;
    background-color: #fff;
    padding: 10px 20px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

#text-display-container {
    background-color: #fff;
    padding: 25px 30px;
    border-radius: 8px;
    margin-bottom: 25px;
    width: 90%;
    max-width: 800px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    font-size: 1.8em;
    text-align: center;
    /* コンテナの高さ制限をなくし、中身に合わせて伸びるようにする */
    height: auto;
}

#text-display {
    letter-spacing: 2px;
    margin-bottom: 10px;
    color: #1a1a1a;
    line-height: 1.5;
    /* 改行の設定 */
    white-space: pre-wrap;
    word-break: break-all;
    overflow-wrap: break-word;
}

#romaji-display {
    font-family: 'SF Mono', 'Consolas', 'Menlo', monospace;
    font-size: 0.8em;
    color: #aaa;
    letter-spacing: 1px;
    min-height: 24px;
    line-height: 1.5;
    /* 改行の設定 */
    white-space: pre-wrap;
    word-break: break-all;
    overflow-wrap: break-word;
}

#romaji-display span.typed { color: #198754; }
#romaji-display span.current { background-color: #d1e7fd; color: #333; border-radius: 3px; }
#romaji-display span.error-char { background-color: #f8d7da; color: #842029; border-radius: 3px; }


#keyboard-container {
    padding: 20px;
    background-color: #fff;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

#keyboard {
    display: grid;
    grid-template-columns: repeat(10, 65px);
    grid-template-rows: repeat(3, 65px);
    gap: 8px;
}

.key {
    width: 65px;
    height: 65px;
    display: flex;
    justify-content: center;
    align-items: center;
    border: 1px solid #ccc;
    border-radius: 6px;
    background-color: #fafafa;
    font-size: 1.3em;
    font-weight: 500;
    user-select: none;
    transition: all 0.1s ease;
    box-sizing: border-box;
}

.key[data-key="enter"] {
    grid-row: span 2;
    height: calc(65px * 2 + 8px);
}

.key.blank {
    background-color: transparent;
    border: none;
}

/* ハイライトの色をCSS変数で制御 */
:root {
    --highlight-opacity: 0.5;
    --highlight-color-rgb: 0, 123, 255; /* Blue */
}

.key.highlight { 
    background-color: rgba(var(--highlight-color-rgb), var(--highlight-opacity));
    border-color: #007bff; 
}
.key.active { background-color: #007bff; color: white; transform: scale(0.95); }
.key.error { background-color: #dc3545; color: white; transform: scale(0.95); }

#reset-button {
    margin-top: 25px;
    padding: 12px 24px;
    font-size: 1.1em;
    cursor: pointer;
    border: none;
    border-radius: 5px;
    background-color: #0d6efd;
    color: white;
    transition: background-color 0.2s;
}

#reset-button:hover { background-color: #0b5ed7; }