* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: "Microsoft Yahei", sans-serif;
}
body {
    background: #f5f5f5;
    padding: 20px;
    max-width: 1200px;
    margin: 0 auto;
}
.container {
    background: white;
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}
h1 {
    text-align: center;
    color: #333;
    margin-bottom: 20px;
}
/* 新增：学习可视化面板 */
.learning-panel {
    background: #f8f9fa;
    border: 1px solid #eee;
    border-radius: 8px;
    padding: 20px;
    margin: 20px 0;
    text-align: center;
}
.learning-panel h3 {
    color: #4285f4;
    margin-bottom: 15px;
}
.playing-info {
    display: flex;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
    margin: 10px 0;
}
.info-item {
    display: flex;
    flex-direction: column;
    align-items: center;
}
.info-label {
    font-size: 12px;
    color: #666;
    margin-bottom: 5px;
}
.info-value {
    font-size: 20px;
    font-weight: 700;
    color: #333;
    min-width: 80px;
    height: 40px;
    line-height: 40px;
    border: 1px solid #ddd;
    border-radius: 4px;
    padding: 0 10px;
    background: white;
}
.key-highlight {
    background: #e0efff !important;
    color: #4285f4 !important;
}
/* 原有样式保留 */
.controls {
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
    margin-bottom: 30px;
    align-items: center;
    justify-content: center;
}
.control-group {
    display: flex;
    align-items: center;
    gap: 8px;
}
label {
    font-weight: 600;
    color: #555;
}
select, input[type="range"], button {
    padding: 8px 12px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 14px;
}
button {
    background: #4285f4;
    color: white;
    border: none;
    cursor: pointer;
    transition: background 0.2s;
}
button:hover {
    background: #3367d6;
}
.keyboard {
    display: flex;
    gap: 5px;
    margin: 30px 0;
    justify-content: center;
    flex-wrap: wrap;
}
.key {
    width: 60px;
    height: 180px;
    background: white;
    border: 2px solid #333;
    border-radius: 8px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: flex-end;
    padding: 10px;
    cursor: pointer;
    transition: all 0.1s;
    font-weight: 600;
}
.key.active, .key.playing {
    background: #e0efff;
    transform: translateY(3px);
    box-shadow: inset 0 2px 5px rgba(0,0,0,0.1);
}
.key span {
    margin-bottom: 10px;
}
.key .note {
    font-size: 18px;
    color: #4285f4;
}
.key .keycode {
    font-size: 12px;
    color: #999;
}
.preset-tips {
    text-align: center;
    color: #666;
    margin-top: 20px;
    font-size: 14px;
}
.octave-tips {
    color: #ff6347;
    font-weight: 600;
    text-align: center;
    margin: 10px 0;
}
/* 新增：预设音乐选择 */
.preset-select {
    margin: 10px 0;
}