:root {
    --max-width: 1280px;
    --header-height: 60px;
}

.page-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 99;
    height: var(--header-height);
    background: white;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.page-header-wrap {
    max-width: var(--max-width);
    height: var(--header-height);
    margin: 0 auto;
}

@media screen and (max-width: 768px) {
    .navbar .nav-inner {
        display: none;
    }

    .navbar .nav-taggle {
        display: block;
    }

    .navbar.is-fixed .nav-inner {
        position: fixed;
        inset: 0;
        display: flex;
        flex-direction: column;
        align-items: center;
        justify-content: center;
        background-color: rgba(0, 0, 0, 0.5);
        backdrop-filter: blur(24px);
        text-align: center;
    }

    .navbar.is-fixed .nav-left,
    .navbar.is-fixed .nav-right {
        display: flex;
        flex-direction: column;
    }

    .navbar.is-fixed .nav-item {
        margin: 0;
        padding: 20px;
        font-size: 20px;
        line-height: 1.5;
        font-weight: bold;
        color: #000;
    }

    .navbar.is-fixed .close {
        display: block;
        margin-top: 20px;
        padding: 20px;
        font-size: 40px;
        line-height: 1;
        cursor: pointer;
    }
}

.main-content {
    position: relative;
    height: calc(100vh - var(--header-height));
    max-width: var(--max-width);
    margin: var(--header-height) auto 0;
    padding: 0 20px;
    box-sizing: border-box;
    display: flex;
    align-items: center;
}

.book-container {
    position: relative;
    width: 100%;
    height: 100%;
    max-width: 800px;
    margin: 0 auto;
    padding: 20px 40px;
    box-sizing: border-box;
    overflow: hidden;
}

.arrow-left,
.arrow-right {
    position: absolute;
    right: 0;
    top: 50%;
    width: 32px;
    height: 32px;
    transform: translateY(-50%);
    cursor: pointer;
}

.arrow-left  {
    left: 0;
}

.arrow-left.disabled,
.arrow-right.disabled {
    opacity: 0.3;
    cursor: not-allowed;
}

.content {
    position: relative;
    width: 100%;
    height: 100%;
    overflow: hidden;
}

.content textArea {
    width: 100%;
    height: 100%;
    padding: 20px;
    box-sizing: border-box;
    font-size: 16px;
    line-height: 1.5;
    font-weight: 500;
    color: #000;
    border: none;
    outline: none;
    resize: none;
}

::-webkit-scrollbar {
    width: 4px;
    height: 0;
}
::-webkit-scrollbar-thumb {
    background-color: #888;
    border-radius: 2px;
}