* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: "Microsoft YaHei", sans-serif;
}

body {
    background-color: #f0f7ff;
    color: #333;
    font-size: 16px;
    line-height: 1.8;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

.header {
    background: #3b82f6;
    color: #fff;
    text-align: center;
    padding: 32px 20px;
}

.header h1 {
    font-size: 30px;
    margin-bottom: 8px;
}

.header p {
    opacity: 0.9;
    font-size: 17px;
}

.grade-block {
    background: #fff;
    border-radius: 14px;
    padding: 24px;
    margin: 24px 0;
    box-shadow: 0 2px 14px #d6e4f7;
}

.grade-block h2 {
    color: #2563eb;
    border-left: 6px solid #3b82f6;
    padding-left: 12px;
    margin-bottom: 20px;
}

.audio-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 18px;
}

.audio-item {
    background: #f6faff;
    border: 1px solid #c7e0fc;
    border-radius: 12px;
    padding: 18px;
}

.audio-item h3 {
    font-size: 18px;
    margin-bottom: 8px;
}

.sub-tag {
    display: inline-block;
    background: #cce0ff;
    color: #1d4ed8;
    font-size: 13px;
    padding: 3px 10px;
    border-radius: 30px;
}

.play-btn {
    display: block;
    text-align: center;
    margin-top: 14px;
    background: #3b82f6;
    color: #fff;
    text-decoration: none;
    padding: 9px;
    border-radius: 10px;
    font-weight: 500;
}

/*播放页面样式*/
.back-btn {
    display: inline-block;
    color: #2563eb;
    text-decoration: none;
    font-size: 18px;
    margin-bottom: 16px;
}

.play-card {
    background: #fff;
    border-radius: 16px;
    padding: 36px;
}

.info-tag {
    color: #666;
    margin: 12px 0 24px;
    font-size: 17px;
}

audio {
    width: 100%;
    margin-bottom: 28px;
}

.text-area {
    background: #f8fbff;
    padding: 24px;
    border-radius: 12px;
    margin: 30px 0;
}

.text-area h3 {
    color: #2563eb;
    margin-bottom: 12px;
}

.qrcode-wrap {
    text-align: center;
    margin-top: 36px;
}

.qrcode-wrap img {
    width: 260px;
    margin: 12px 0;
    border: 8px solid #f0f7ff;
    border-radius: 12px;
}