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

:root {
    --color-bg: #ffffff;
    --color-text: #1a1a1a;
    --color-text-light: #555555;
    --color-primary: #2a5aa7;
    --color-border: #e0e0e0;
    --color-code-bg: #f5f5f5;
    --font-body: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    --font-heading: Georgia, "Times New Roman", serif;
    --max-width: 720px;
    --spacing-unit: 1.5rem;
}

html {
    font-size: 18px;
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-body);
    color: var(--color-text);
    background-color: var(--color-bg);
    padding: 0;
    margin: 0;
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-unit);
}

a {
    color: var(--color-primary);
    text-decoration: none;
    transition: color 0.2s ease;
}

a:hover {
    color: #1a3d7a;
    text-decoration: underline;
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    font-weight: 600;
    line-height: 1.3;
    margin-top: 2rem;
    margin-bottom: 1rem;
    color: var(--color-text);
}

h1 {
    font-size: 2.2rem;
    margin-top: 0;
}

h2 {
    font-size: 1.8rem;
    border-bottom: 1px solid var(--color-border);
    padding-bottom: 0.5rem;
}

h3 {
    font-size: 1.4rem;
}

h4 {
    font-size: 1.2rem;
}

p {
    margin-bottom: 1.2rem;
}

ul, ol {
    margin-bottom: 1.2rem;
    padding-left: 2rem;
}

li {
    margin-bottom: 0.5rem;
}

blockquote {
    border-left: 4px solid var(--color-primary);
    padding-left: 1.5rem;
    margin: 2rem 0;
    font-style: italic;
    color: var(--color-text-light);
}

code {
    font-family: "SF Mono", Monaco, "Cascadia Code", "Roboto Mono", Consolas, monospace;
    font-size: 0.9em;
    background-color: var(--color-code-bg);
    padding: 0.2em 0.4em;
    border-radius: 3px;
}

pre {
    background-color: var(--color-code-bg);
    padding: 1rem;
    border-radius: 4px;
    overflow-x: auto;
    margin-bottom: 1.5rem;
}

pre code {
    background-color: transparent;
    padding: 0;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
    margin: 2rem auto;
}

.book-cover {
    max-width: 300px;
    margin: 0 auto 2rem auto;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.book-cover img {
    margin: 0;
    width: 100%;
    height: auto;
}

hr {
    border: none;
    border-top: 1px solid var(--color-border);
    margin: 2rem 0;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 1.5rem;
}

th, td {
    border: 1px solid var(--color-border);
    padding: 0.75rem;
    text-align: left;
}

th {
    background-color: var(--color-code-bg);
    font-weight: 600;
}

.site-header {
    border-bottom: 1px solid var(--color-border);
    padding: 1.5rem 0;
    margin-bottom: 2rem;
}

.site-header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
}

.site-title {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--color-text);
    text-decoration: none;
}

.site-title:hover {
    color: var(--color-primary);
    text-decoration: none;
}

.nav-list {
    list-style: none;
    display: flex;
    gap: 1.5rem;
    margin: 0;
    padding: 0;
}

.nav-item {
    margin: 0;
}

.nav-link {
    color: var(--color-text-light);
    font-size: 0.95rem;
    font-weight: 500;
}

.nav-link:hover {
    color: var(--color-primary);
    text-decoration: none;
}

.nav-link.active {
    color: var(--color-primary);
}

.home-content,
.single-content,
.list-content {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-unit);
}

.article-header {
    margin-bottom: 2rem;
}

.article-title {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

.article-book {
    font-size: 1.1rem;
    color: var(--color-text-light);
    margin-bottom: 0.5rem;
}

.article-date {
    font-size: 0.9rem;
    color: var(--color-text-light);
    display: block;
}

.article-body {
    margin-bottom: 3rem;
}

.chapter-nav {
    display: flex;
    justify-content: space-between;
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid var(--color-border);
    gap: 1rem;
}

.nav-prev,
.nav-next {
    font-size: 0.95rem;
    color: var(--color-primary);
}

.section-header {
    margin-bottom: 2rem;
}

.section-title {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

.section-description {
    font-size: 1.1rem;
    color: var(--color-text-light);
}

.section-body {
    margin-bottom: 2rem;
}

.content-list {
    list-style: none;
    padding: 0;
}

.content-item {
    margin-bottom: 2rem;
    padding-bottom: 2rem;
    border-bottom: 1px solid var(--color-border);
}

.content-item:last-child {
    border-bottom: none;
}

.content-link {
    font-size: 1.3rem;
    font-weight: 600;
    display: block;
    margin-bottom: 0.5rem;
}

.content-excerpt {
    color: var(--color-text-light);
    font-size: 1rem;
    margin: 0;
}

.site-footer {
    border-top: 1px solid var(--color-border);
    padding: 2rem 0;
    margin-top: 4rem;
    font-size: 0.9rem;
    color: var(--color-text-light);
}

.site-footer .container {
    text-align: center;
}

.site-footer p {
    margin-bottom: 0.5rem;
}

.ai-notice {
    font-size: 0.85rem;
    font-style: italic;
}

.breadcrumb {
    font-size: 0.9rem;
    margin-bottom: 1.5rem;
    color: var(--color-text-light);
}

.breadcrumb ol {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.breadcrumb li:not(:last-child)::after {
    content: "/";
    margin-left: 0.5rem;
    color: var(--color-border);
}

.breadcrumb a {
    color: var(--color-text-light);
}

.breadcrumb a:hover {
    color: var(--color-primary);
}

.breadcrumb li:last-child {
    color: var(--color-text);
}

@media (max-width: 768px) {
    html {
        font-size: 16px;
    }
    
    .site-header .container {
        flex-direction: column;
        align-items: flex-start;
        gap: 1rem;
    }
    
    .nav-list {
        flex-wrap: wrap;
        gap: 1rem;
    }
    
    .article-title,
    .section-title {
        font-size: 2rem;
    }
    
    .chapter-nav {
        flex-direction: column;
    }
}

@media (max-width: 480px) {
    .nav-list {
        flex-direction: column;
        gap: 0.5rem;
    }
    
    h1 {
        font-size: 1.8rem;
    }
    
    h2 {
        font-size: 1.5rem;
    }
}