* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    height: 100vh;
    width: 100vw;
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: sans-serif;
    overflow: hidden;
    background-color: black;
}

.content {
    background-color: #EDE1C0;
    width: 100vw;
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
}

.book {
    width: 80%;
    height: 80%;
    position: relative;
    perspective: 1500px;
    transition: transform 0.5s;
    transform-style: preserve-3d;
}

#viewer {
    width: 100%;
    height: 100%;
    position: absolute;
    top: 0;
    left: 0;
    transition: transform 0.5s ease-in-out;
    transform-origin: left center;
    background: white;
    backface-visibility: hidden;
}

#toc {
    position: absolute;
    top: 10px;
    left: 10px;
    max-width: 300px;
    max-height: 80%;
    overflow-y: auto;
    background-color: rgba(255, 255, 255, 0.9);
    padding: 10px;
    border-radius: 5px;
    font-size: 14px;
}

#toc div {
    cursor: pointer;
    margin-bottom: 5px;
    padding: 5px;
    border-bottom: 1px solid #eee;
}

#toc div:hover {
    background-color: #f0f0f0;
}

#navigationButtons {
    display: flex;
    gap: 10px;
}

#navigationButtons button {
    padding: 10px 20px;
    font-size: 16px;
    border: none;
    background-color: #333;
    color: white;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

#navigationButtons button:disabled {
    background-color: #999;
    cursor: not-allowed;
}

#navigationButtons button:hover:not(:disabled) {
    background-color: #555;
}