:root {
    --background-color: #f0f0f0;
    --text-color: #333;
    --header-bg: #212529;
    --header-text: #fff;
    --search-button-bg: #3498db;
    --search-button-hover: #2980b9;
    --title-bg: #3498db;
    --title-hover: #2980b9;
    --chapter-bg: #ecf0f1;
    --chapter-hover: #bdc3c7;
    --section-bg: #f8f9fa;
    --section-hover: #e9ecef;
    --content-bg: #fff;
    --content-shadow: rgba(0,0,0,0.1);
    --border-color: #3498db;
    --heading-color: #2c3e50;
    --icon-color: #3498db;
    --icon-hover: #2980b9;
    --disabled-color: #bdc3c7;
}

@media (prefers-color-scheme: dark) {
    :root {
        --background-color: #1a1a1a;
        --text-color: #e0e0e0;
        --header-bg: #2c3e50;
        --header-text: #fff;
        --search-button-bg: #2980b9;
        --search-button-hover: #3498db;
        --title-bg: #2980b9;
        --title-hover: #3498db;
        --chapter-bg: #00000000;
        --chapter-hover: #34495e;
        --section-bg: #34495e;
        --section-hover: #2c3e50;
        --content-bg: #2c3e50;
        --content-shadow: rgba(0,0,0,0.3);
        --border-color: #3498db;
        --heading-color: #ecf0f1;
        --icon-color: #3498db;
        --icon-hover: #2980b9;
        --disabled-color: #7f8c8d;
    }
}

body {
    font-family: 'Roboto', sans-serif;
    line-height: 1.5;
    margin: 0;
    padding: 0;
    background-color: var(--background-color);
    color: var(--text-color);
}

header {
    background-color: var(--header-bg);
    color: var(--header-text);
    text-align: center;
    padding: 1rem;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

main {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
}

.search-container {
    display: flex;
    justify-content: center;
    align-items: center;
    margin-bottom: 20px;
}

#search-input {
    width: 70%;
    padding: 12px 15px;
    font-size: 16px;
    color: var(--text-color);
    background-color: var(--background-color);
    border: 2px solid var(--border-color);
    border-radius: 5px;
    box-shadow: 0 2px 5px var(--content-shadow);
    transition: border-color 0.3s, box-shadow 0.3s;
}

#search-input::placeholder {
    color: var(--disabled-color);
}

#search-input:focus {
    outline: none;
    border-color: var(--icon-hover);
    box-shadow: 0 2px 10px var(--content-shadow);
}

#search-button {
    padding: 12px 20px;
    font-size: 16px;
    background-color: var(--search-button-bg);
    color: var(--header-text);
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s, transform 0.2s;
    margin-left: 10px;
}

#search-button:hover {
    background-color: var(--search-button-hover);
    transform: translateY(-2px);
}

#search-button:active {
    transform: translateY(1px);
}

.title {
    background-color: var(--title-bg);
    color: var(--header-text);
    padding: 10px;
    margin-bottom: 5px;
    cursor: pointer;
    border-radius: 5px;
    transition: background-color 0.3s;
}

.title:hover {
    background-color: var(--title-hover);
}

.chapters {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-out;
}

.chapters.active {
    max-height: 1000px;
    transition: max-height 0.5s ease-in;
}

.chapter {
    background-color: var(--chapter-bg);
    padding: 10px;
    margin-bottom: 5px;
    cursor: pointer;
    border-radius: 5px;
    transition: background-color 0.3s;
}

.chapter:hover {
    background-color: var(--chapter-hover);
}

.section {
    background-color: var(--section-bg);
    padding: 10px;
    margin-bottom: 5px;
    cursor: pointer;
    border-radius: 5px;
    transition: background-color 0.3s;
}

.section:hover {
    background-color: var(--section-hover);
}

#section-content {
    margin-top: 0px;
    background-color: var(--content-bg);
    padding: 5px 15px;
    border-radius: 5px;
}

#section-content table {
    border-collapse: collapse;
    width: 100%;
    margin: 1em 0;
}

#section-content th, #section-content td {
    border: 1px solid #ddd;
    padding: 8px;
    text-align: left;
}

#section-content th {
    background-color: #f2f2f2;
}

#chapter-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 10px;
    margin-bottom: 20px;
}

#chapter-header h2 {
    margin: 0;
    color: var(--heading-color);
}

.icon-button {
    background: none;
    border: none;
    cursor: pointer;
    padding: 5px;
}

.icon-button svg {
    width: 24px;
    height: 24px;
    fill: var(--icon-color);
}

.icon-button:hover svg {
    fill: var(--icon-hover);
}

#section-navigation {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0px;
}

.arrow-group {
    display: flex;
}

.arrow-button {
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    padding: 0 10px;
    color: var(--icon-color);
}

.arrow-button:hover {
    color: var(--icon-hover);
}

.arrow-button:disabled {
    color: var(--disabled-color);
    cursor: not-allowed;
}

#back-to-sections {
    padding: 5px 10px;
    background-color: var(--search-button-bg);
    color: var(--header-text);
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s;
}

#back-to-sections:hover {
    background-color: var(--search-button-hover);
}

#section-text {
    margin-top: 20px;
}

.hidden {
    display: none;
}

.loading, .error {
    text-align: center;
    font-size: 18px;
    margin-top: 20px;
}

.error {
    color: #e74c3c;
}

h3 {
    color: var(--heading-color);
}

.highlight-red {
    color: #dc3545;
}

.highlight-orange {
    color: #fd7e14;
}

.highlight-green {
    color: #198754;
}