body {
    margin:0;
    font-family: Arial, sans-serif;
    background:#f4f4f4;
    position: relative;
}
#pdf-container {
    width: 90%;
    max-width: 900px;
    margin: 20px auto;
    background: #fff;
    padding: 15px;
    box-shadow: 0 0 10px rgba(0,0,0,0.2);
}
.pdf-page {
    display: flex;
    justify-content: center;
    margin-bottom: 15px;
}
#pdf-toolbar {
    text-align:center;
    margin-bottom: 10px;
}
#pdf-toolbar span {
    font-weight: bold;
}


.audio-selector.fixed {
    position: fixed;
    bottom: 5px;
    padding-bottom: 20px;
    left: 50%; 
    transform: translateX(-50%);

    /*background: rgba(70, 70, 70, 0.6);*/
    /*padding: 10px 16px;*/
    /*border-radius: 20px;*/
    /*backdrop-filter: blur(8px);*/
    /*box-shadow: 0 4px 12px rgba(0, 0, 0, 0.25);*/
    font-family: "Segoe UI", sans-serif;
    z-index: 999999;
    text-align: center; /* canh giữa phần nội dung */
    max-width: 700px; 
    width: 100%; 
}
/* chỉ cho hàng nút nằm ngang */
.audio-selector .button-row {
    display: flex;
    align-items: center;
    justify-content: center;
    flex-wrap: wrap;
}

/* label + các nút */
.audio-selector .label {
    display: flex;
    align-items: center;
    color: #fff;
    font-size: 14px;
    white-space: nowrap;
}

.audio-selector .label .icon {
    width: 16px;
    height: 16px;
    margin-right: 6px;
    vertical-align: middle;
    filter: brightness(0) invert(1);
}

.audio-selector .part {
    background: #fff;
    border: 1px solid #fff !important;
    border: none;
    color: #878787;
    font-size: 14px;
    border-radius: 20px;
    padding: 7px 19px;
    cursor: pointer;
    transition: all 0.25s ease;
}

.audio-selector .part:hover {
    background: #d0d0d0;
}

.audio-selector .part.active {
    background: #00aaff;
    color: #fff;
}

/* audio-list nằm xuống dưới */
.audio-selector .audio-list {
    margin-top: 10px;
}

.audio-selector .audio-item {
    display: none;
}

.flex-listen {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 8px;
    background: #46464699;
    border-radius: 50px;
    border: 1px solid #fff;
    padding: 8px 16px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.25);
}

.audio-list audio {
    width: 100%;
    box-shadow: 0px 4px 6.6px 0px #0000002B;
    border-radius: 50px;
    border: 1px solid #fff;
}

@media screen and (max-width: 1080px) {
    div#pdf-viewer-container canvas {
        width: 100%;
        height: auto;
        aspect-ratio: unset;
    }
}

@media screen and (max-width: 767px) {
    .audio-selector .part {
        font-size: 10px;
        font-weight: 500;
    }

    .audio-selector.fixed {
        padding-left: 10px;
        padding-right: 10px;
        box-sizing: border-box;
        bottom: 0;
    }
}

/* Audio Player Fixed */
.audio-player-fixed {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    z-index: 999999;
    padding: 15px 20px;
    text-align: center;
}

.audio-player-container {
    max-width: 1200px;
    margin: 0 auto;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background: rgba(70, 70, 70, 0.4);
    backdrop-filter: blur(4px);
    border: 1px solid #fff;
    padding: 10px 20px;
    border-radius: 50px;
    box-shadow: 0 -4px 20px rgba(0, 0, 0, 0.3);
}

.audio-player-header {
    display: flex;
    align-items: center;
    /* margin-bottom: 10px; */
    color: #fff;
    margin-right: 10px;
}

.audio-player-header .audio-icon {
    width: 20px;
    height: 20px;
    margin-right: 8px;
    filter: brightness(0) invert(1);
}

.audio-player-header .audio-title {
    font-size: 14px;
    font-weight: 500;
    display: flex;
    align-items: center;
}

.audio-player-list {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.audio-player-list .audio-link {
    display: inline-block;
    padding: 8px 16px;
    background: #fff;
    border-radius: 20px;
    text-decoration: none;
    color: #333;
    font-size: 13px;
    transition: all 0.3s ease;
    cursor: pointer;
    border: 1px solid transparent;
}

.audio-player-list .audio-link:hover {
    background: #00B0DD;
    transform: translateY(-2px);
    color: #fff;
}

.audio-player-list .audio-link.active {
    background: #00B0E8;
    color: #fff;
    font-weight: bold;
    border-color: #fff;
}

.audio-player-list .audio-link.active:hover {
    background: #0099ee;
}

.audio-player-controls {
    margin-top: 15px;
    /* padding-top: 15px; */
    border-top: 1px solid rgba(255, 255, 255, 0.2);
    max-width: 480px;
    box-shadow: 0 -4px 20px rgba(0, 0, 0, 0.3);
    margin: 10px auto 0px;
    border-radius: 50px;
    overflow: hidden;
}

.audio-player-controls audio {
    width: 100%;
    height: 45px;
    /* border-radius: 8px; */
    background: #fff;
    padding-top: 5px;
}

.audio-player-controls audio::-webkit-media-controls-panel {
    background-color: #fff;
}

@media screen and (max-width: 767px) {
    .audio-player-fixed {
        padding: 10px 15px;
    }
    
    .audio-player-header .audio-title {
        font-size: 12px;
    }
    
    .audio-player-list .audio-link {
        font-size: 11px;
        padding: 6px 12px;
    }
}