body {
    background-color: #9ebbe4;
    font-family: 'Fira Sans', serif;
    display: flex;
    flex-direction: column;
    align-items: center;
    margin: 0;
    padding: 0;
}

#book-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 10px;
    width: 100%; 
    position: relative;
}

.book {
    width: 90%; 
    max-width: 1200px; 
    height: 850px;
    position: relative;
    display: flex;
    box-shadow: 0 20px 30px rgba(0, 0, 0, 0.3);
    background-color: #fdfdfd;
    transform-style: preserve-3d;
    border-radius: 10px;
    overflow: hidden;
}

.page-pair {
    display: flex;
    width: 100%;
    height: 100%;
    border-radius: 10px;
    display: none; 
}

.page-single {
    display: flex;
    width: 100%;
    height: 100%; 
    border-radius: 10px;
    display: none; 
    padding-bottom: 40px;
}

.page {
    width: 50%;
    padding: 20px; 
    box-sizing: border-box;
    background-color: #fffefb;
    box-shadow: inset 10px 0 20px rgba(0, 0, 0, 0.1);
    overflow-y: auto; 
    display: flex; 
    flex-direction: column;
    justify-content: center; 
    align-items: center; 
    padding-bottom: 40px; 
}

.left-page {
    border-right: 1px solid #ccc;
    color: #000;
    font-family: "Fira Sans";
    font-size: 22px;
    font-style: normal;
    font-weight: 300;
    line-height: normal;
}

.right-page {
    padding-left: 20px;
    color: #000;
    font-family: "Fira Sans";
    font-size: 22px;
    font-style: normal;
    font-weight: 300;
    line-height: normal;
}

.full-page {
    width: 100%; 
    background-color: #fffefb;
    padding: 20px;
    box-sizing: border-box;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

.citation {
    padding-left: 20px;
    color: #000;
    font-family: "Fira Sans";
    font-size: 14px;
    font-style: normal;
    font-weight: 300;
    line-height: normal;
}

.activity {
    padding-left: 20px;
    color: #000000;
    font-family: "Fira Sans";
    font-size: 22px;
    font-style: normal;
    font-weight: 200;
    line-height: normal;
}

.chapter-title {
    font-size: 2em; 
    margin: 0; 
    text-align: left; 
    color: #000;
    font-family: "Fira Sans";
    font-size: 52px;
    font-style: normal;
    font-weight: 900;
    line-height: normal;
    width: 100%; 
}

.character-image {
    width: 100%; 
    height: auto; 
    max-width: 100%;
    margin-bottom: 5px;
    padding: 0;
    object-fit: contain; 
}

.corner-image {
    bottom: 0; 
    left: 0; 
    max-width: 100%;
    width: 200px;
    height: 200px;
    object-fit: contain; 
  }

.image {
    width: 90%; 
    height: auto; 
    max-width: 100%; 
    padding: 5px;
    border-radius: 20px;
}

iframe {
    width: 100%; 
    height: auto;
    aspect-ratio: 16/9; 
    border: none;
}

.navigation {
    margin-top: 20px;
}

.navigation button {
    padding: 10px 20px;
    font-size: 16px;
    margin: 0 10px;
    background-color: #333;
    color: white;
    border: none;
    cursor: pointer;
    border-radius: 5px;
    transition: background-color 0.3s;
}

.navigation button:hover {
    background-color: #555;
}

.page-number {
    position: absolute;
    bottom: 10px;
    font-size: 14px;
    color: #666;
    font-family: 'Fira Sans', serif;
}

.page-number.left {
    left: 20px; 
}

.page-number.right {
    right: 20px; 
}

.page-number.hide {
    display: none;
}

#progress-bar-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    width: 90%; 
    max-width: 1200px; 
    margin: 30px 0 10px 0; 
    position: relative;
    z-index: 10;
}

#progress-bar {
    width: 100%; 
    height: 30px; 
    background-color: #ddd; 
    border-radius: 15px; 
    overflow: hidden; 
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2); 
    position: relative; 
}

#progress-fill {
    width: 0%; 
    height: 100%;
    background: linear-gradient(90deg, #4CAF50, #1E90FF);
    transition: width 0.4s ease;
    border-radius: 15px; 
    position: relative;
}

#lamp-icon {
    position: absolute;
    top: 0px; 
    left: 0;
    width: 30px;  
    height: 30px; 
    transition: left 0.4s ease; 
    pointer-events: none;  
    z-index: 5;  
}

@media (max-width: 768px) {
    .book {
        width: 100%; 
        max-width: 100%; 
        height: auto; 
    }

    .page-pair {
        flex-direction: column; 
        height: auto; 
    }

    .page {
        width: 100%; 
        padding: 10px; 
        box-shadow: none; 
        justify-content: flex-start; 
    }

    .left-page {
        border-right: none; 
        border-bottom: 1px solid #ccc; 
    }

    .right-page {
        padding-left: 10px;
    }

    h1, h2 {
        font-size: 1.5em; 
    }

    .chapter-title {
        font-size: 1.8em; 
        text-align: left; 
    }

    p {
        font-size: 0.9em; 
    }

    iframe {
        height: calc(100vh - 50px);
    }

    .character-image {
        width: 100%;
        max-width: 100%; 
    }

    .corner-image{
        width: 100%;
        max-width: 100%;
    }

    .navigation button {
        padding: 8px 12px; 
        font-size: 14px; 
        margin: 5px; 
    }

    .page-number {
        display: none;
    }

}

@media (min-width: 769px) and (max-width: 1024px) {
    .book {
        width: 95%;
        max-width: 1000px; 
        height: 700px; 
    }

    .page-pair {
        height: 100%; 
    }

    .page {
        padding: 20px;
        justify-content: center; 
    }

    .navigation button {
        padding: 10px 20px;
        font-size: 16px;
    }

    iframe {
        height: 100%; 
    }
}