.pdf-viewer {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 20px;
    background-color: #f4f4f4;
    display: flex;
    flex-direction: column;
    align-items: center;
}
#pdf-container {
    width: 100%;
    max-width: 800px;
    border: 1px solid #ccc;
    background-color: #fff;
    overflow-y: auto;
    height: 70vh;
    margin-bottom: 20px;
}
#controls {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
}
button {
    padding: 8px 16px;
    background-color: #007bff;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
}
button:hover {
    background-color: #0056b3;
}
canvas {
    width: 100%;
    margin-bottom: 10px;
}
.text-layer {
    position: absolute;
    left: 0;
    top: 0;
    right: 0;
    bottom: 0;
    overflow: hidden;
    opacity: 0.2;
    line-height: 1.0;
}
.text-layer > span {
    color: transparent;
    position: absolute;
    white-space: pre;
    cursor: text;
}