/*
Theme Name: GEO Optimized
Theme URI: https://example.com/geo-optimized-theme
Author: GEO Theme Developer
Author URI: https://example.com
Description: A minimalist WordPress theme optimized for Generative Engine Optimization (GEO). Designed to maximize content indexing by AI search engines (Qwen, Doubao, ChatGPT, Perplexity, etc.) through comprehensive Schema.org structured data, semantic HTML5, and ultra-fast loading performance.
Version: 1.0.0
Requires at least: 6.0
Tested up to: 6.5
Requires PHP: 8.0
License: GNU General Public License v2 or later
License URI: https://www.gnu.org/licenses/gpl-2.0.html
Text Domain: geo-optimized
Tags: blog, one-column, right-sidebar, custom-menu, featured-images, translation-ready, blog
*/

/* ==========================================================================
   CSS Custom Properties
   ========================================================================== */

:root {
    --color-primary: #1a1a2e;
    --color-secondary: #16213e;
    --color-accent: #0f3460;
    --color-link: #2563eb;
    --color-link-hover: #1d4ed8;
    --color-text: #1f2937;
    --color-text-light: #6b7280;
    --color-bg: #ffffff;
    --color-bg-alt: #f9fafb;
    --color-border: #e5e7eb;
    --color-code-bg: #f3f4f6;
    --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
        "Helvetica Neue", Arial, "Noto Sans SC", "PingFang SC",
        "Microsoft YaHei", sans-serif;
    --font-mono: "SF Mono", "Fira Code", "Fira Mono", "Roboto Mono",
        "Courier New", monospace;
    --max-width: 720px;
    --max-width-wide: 960px;
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --radius: 4px;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.1), 0 1px 2px rgba(0, 0, 0, 0.06);
}

/* ==========================================================================
   Reset & Base
   ========================================================================== */

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

html {
    font-size: 16px;
    -webkit-text-size-adjust: 100%;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    font-size: 1rem;
    line-height: 1.8;
    color: var(--color-text);
    background-color: var(--color-bg);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-wrap: break-word;
}

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

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

a:hover,
a:focus {
    color: var(--color-link-hover);
    text-decoration: underline;
}

a:focus-visible {
    outline: 2px solid var(--color-link);
    outline-offset: 2px;
}

/* ==========================================================================
   Layout
   ========================================================================== */

.site-wrapper {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

.site-content {
    flex: 1;
    width: 100%;
    max-width: var(--max-width-wide);
    margin: 0 auto;
    padding: var(--spacing-xl) var(--spacing-md);
    display: grid;
    grid-template-columns: 1fr 280px;
    gap: var(--spacing-2xl);
}

.content-area {
    min-width: 0;
}

/* ==========================================================================
   Header
   ========================================================================== */

.site-header {
    background-color: var(--color-primary);
    color: #ffffff;
    padding: var(--spacing-md) 0;
    border-bottom: 3px solid var(--color-accent);
}

.site-header .container {
    max-width: var(--max-width-wide);
    margin: 0 auto;
    padding: 0 var(--spacing-md);
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

.site-branding {
    display: flex;
    flex-direction: column;
}

.site-title {
    font-size: 1.25rem;
    font-weight: 700;
    line-height: 1.3;
    margin: 0;
}

.site-title a {
    color: #ffffff;
    text-decoration: none;
}

.site-title a:hover {
    color: #e2e8f0;
    text-decoration: none;
}

.site-description {
    font-size: 0.8125rem;
    color: #94a3b8;
    margin-top: var(--spacing-xs);
}

/* Navigation */

.main-navigation ul {
    list-style: none;
    display: flex;
    gap: var(--spacing-lg);
    margin: 0;
    padding: 0;
}

.main-navigation a {
    color: #e2e8f0;
    font-size: 0.875rem;
    font-weight: 500;
    padding: var(--spacing-xs) 0;
    text-decoration: none;
}

.main-navigation a:hover,
.main-navigation .current-menu-item > a {
    color: #ffffff;
    border-bottom: 2px solid #ffffff;
    text-decoration: none;
}

/* ==========================================================================
   Breadcrumb
   ========================================================================== */

.breadcrumb {
    font-size: 0.8125rem;
    color: var(--color-text-light);
    padding: var(--spacing-sm) 0;
    margin-bottom: var(--spacing-md);
    border-bottom: 1px solid var(--color-border);
}

.breadcrumb ol {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
    margin: 0;
    padding: 0;
}

.breadcrumb li {
    display: flex;
    align-items: center;
}

.breadcrumb li + li::before {
    content: "\203A";
    margin-right: var(--spacing-xs);
    color: var(--color-text-light);
}

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

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

.breadcrumb .current {
    color: var(--color-text);
    font-weight: 500;
}

/* ==========================================================================
   Article / Post Styles
   ========================================================================== */

article {
    margin-bottom: var(--spacing-2xl);
}

article:last-child {
    margin-bottom: 0;
}

/* Post Header */

.entry-header {
    margin-bottom: var(--spacing-lg);
}

.entry-title {
    font-size: 1.75rem;
    font-weight: 800;
    line-height: 1.3;
    color: var(--color-primary);
    margin-bottom: var(--spacing-sm);
    letter-spacing: -0.02em;
}

.entry-title a {
    color: inherit;
    text-decoration: none;
}

.entry-title a:hover {
    color: var(--color-link);
    text-decoration: none;
}

/* Post Meta */

.entry-meta {
    font-size: 0.8125rem;
    color: var(--color-text-light);
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
    align-items: center;
}

.entry-meta time,
.entry-meta .author,
.entry-meta .category-link {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.entry-meta .separator {
    color: var(--color-border);
}

/* Single Post Title - larger */

.single .entry-title {
    font-size: 2rem;
    line-height: 1.25;
}

/* Post Content - optimized for readability and AI parsing */

.entry-content {
    font-size: 1.0625rem;
    line-height: 1.9;
    color: var(--color-text);
}

.entry-content h2 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-top: var(--spacing-2xl);
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-sm);
    border-bottom: 1px solid var(--color-border);
    color: var(--color-primary);
    scroll-margin-top: 1rem;
}

.entry-content h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-top: var(--spacing-xl);
    margin-bottom: var(--spacing-sm);
    color: var(--color-secondary);
    scroll-margin-top: 1rem;
}

.entry-content h4 {
    font-size: 1.0625rem;
    font-weight: 600;
    margin-top: var(--spacing-lg);
    margin-bottom: var(--spacing-sm);
    color: var(--color-text);
    scroll-margin-top: 1rem;
}

.entry-content p {
    margin-bottom: var(--spacing-lg);
}

.entry-content ul,
.entry-content ol {
    margin-bottom: var(--spacing-lg);
    padding-left: var(--spacing-xl);
}

.entry-content li {
    margin-bottom: var(--spacing-xs);
}

.entry-content blockquote {
    border-left: 4px solid var(--color-accent);
    margin: var(--spacing-lg) 0;
    padding: var(--spacing-md) var(--spacing-lg);
    background-color: var(--color-bg-alt);
    color: var(--color-text);
    font-style: italic;
    border-radius: 0 var(--radius) var(--radius) 0;
}

.entry-content pre {
    background-color: var(--color-code-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    padding: var(--spacing-md);
    overflow-x: auto;
    font-family: var(--font-mono);
    font-size: 0.875rem;
    line-height: 1.6;
    margin-bottom: var(--spacing-lg);
}

.entry-content code {
    font-family: var(--font-mono);
    font-size: 0.875em;
    background-color: var(--color-code-bg);
    padding: 0.15em 0.4em;
    border-radius: 3px;
}

.entry-content pre code {
    background: none;
    padding: 0;
    font-size: inherit;
}

.entry-content table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: var(--spacing-lg);
    font-size: 0.9375rem;
}

.entry-content th,
.entry-content td {
    border: 1px solid var(--color-border);
    padding: var(--spacing-sm) var(--spacing-md);
    text-align: left;
}

.entry-content th {
    background-color: var(--color-bg-alt);
    font-weight: 600;
}

.entry-content figure {
    margin: var(--spacing-lg) 0;
}

.entry-content figcaption {
    font-size: 0.8125rem;
    color: var(--color-text-light);
    text-align: center;
    margin-top: var(--spacing-sm);
}

.entry-content img {
    border-radius: var(--radius);
}

/* Heading anchors for AI citation */

.heading-anchor {
    color: var(--color-text-light);
    text-decoration: none;
    margin-left: var(--spacing-xs);
    opacity: 0;
    transition: opacity 0.2s ease;
    font-weight: 400;
}

.entry-content h2:hover .heading-anchor,
.entry-content h3:hover .heading-anchor,
.entry-content h4:hover .heading-anchor {
    opacity: 1;
}

.heading-anchor:hover {
    color: var(--color-link);
    text-decoration: none;
}

/* Post Footer / Tags */

.entry-footer {
    margin-top: var(--spacing-xl);
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--color-border);
}

.entry-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
    list-style: none;
    margin: 0;
    padding: 0;
}

.entry-tags a {
    display: inline-block;
    font-size: 0.75rem;
    color: var(--color-text-light);
    background-color: var(--color-bg-alt);
    border: 1px solid var(--color-border);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius);
    text-decoration: none;
}

.entry-tags a:hover {
    color: var(--color-link);
    border-color: var(--color-link);
    text-decoration: none;
}

/* ==========================================================================
   Post Listing (Index / Archive)
   ========================================================================== */

.post-list {
    list-style: none;
    margin: 0;
    padding: 0;
}

.post-list article {
    padding-bottom: var(--spacing-xl);
    border-bottom: 1px solid var(--color-border);
}

.post-list .entry-title {
    font-size: 1.375rem;
}

.post-list .entry-excerpt {
    font-size: 0.9375rem;
    color: var(--color-text-light);
    line-height: 1.7;
    margin-top: var(--spacing-sm);
}

.post-list .read-more {
    display: inline-block;
    font-size: 0.875rem;
    font-weight: 500;
    margin-top: var(--spacing-sm);
}

/* ==========================================================================
   Related Posts
   ========================================================================== */

.related-posts {
    margin-top: var(--spacing-2xl);
    padding-top: var(--spacing-xl);
    border-top: 2px solid var(--color-border);
}

.related-posts h3 {
    font-size: 1.125rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    color: var(--color-primary);
}

.related-posts-list {
    list-style: none;
    margin: 0;
    padding: 0;
    display: grid;
    gap: var(--spacing-md);
}

.related-posts-list li {
    padding: var(--spacing-md);
    background-color: var(--color-bg-alt);
    border-radius: var(--radius);
    border: 1px solid var(--color-border);
}

.related-posts-list a {
    font-weight: 600;
    font-size: 0.9375rem;
    display: block;
}

.related-posts-list time {
    font-size: 0.75rem;
    color: var(--color-text-light);
    margin-top: var(--spacing-xs);
    display: block;
}

/* ==========================================================================
   FAQ Section
   ========================================================================== */

.faq-section {
    margin-top: var(--spacing-2xl);
    padding-top: var(--spacing-xl);
    border-top: 1px solid var(--color-border);
}

.faq-section h3 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: var(--spacing-lg);
    color: var(--color-primary);
}

.faq-item {
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-lg);
    border-bottom: 1px solid var(--color-border);
}

.faq-item:last-child {
    border-bottom: none;
    padding-bottom: 0;
}

.faq-question {
    font-size: 1.0625rem;
    font-weight: 600;
    color: var(--color-primary);
    margin-bottom: var(--spacing-sm);
    cursor: pointer;
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-sm);
}

.faq-question::before {
    content: "Q";
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 1.5em;
    height: 1.5em;
    background-color: var(--color-accent);
    color: #ffffff;
    border-radius: 50%;
    font-size: 0.75rem;
    font-weight: 700;
    flex-shrink: 0;
    margin-top: 0.2em;
}

.faq-answer {
    font-size: 0.9375rem;
    color: var(--color-text);
    line-height: 1.8;
    padding-left: calc(1.5em + var(--spacing-sm));
}

/* ==========================================================================
   Sidebar
   ========================================================================== */

.sidebar {
    font-size: 0.875rem;
}

.widget {
    margin-bottom: var(--spacing-xl);
    padding: var(--spacing-lg);
    background-color: var(--color-bg-alt);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
}

.widget-title {
    font-size: 0.9375rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-sm);
    border-bottom: 2px solid var(--color-accent);
    color: var(--color-primary);
}

.widget ul {
    list-style: none;
    margin: 0;
    padding: 0;
}

.widget li {
    padding: var(--spacing-xs) 0;
    border-bottom: 1px solid var(--color-border);
}

.widget li:last-child {
    border-bottom: none;
}

.widget li a {
    color: var(--color-text);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.widget li a:hover {
    color: var(--color-link);
    text-decoration: none;
}

/* Search Form */

.search-form {
    display: flex;
    gap: var(--spacing-sm);
}

.search-form .search-field {
    flex: 1;
    padding: var(--spacing-sm) var(--spacing-md);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    font-size: 0.875rem;
    font-family: var(--font-sans);
    outline: none;
}

.search-form .search-field:focus {
    border-color: var(--color-link);
    box-shadow: 0 0 0 2px rgba(37, 99, 235, 0.2);
}

.search-form .search-submit {
    padding: var(--spacing-sm) var(--spacing-md);
    background-color: var(--color-accent);
    color: #ffffff;
    border: none;
    border-radius: var(--radius);
    font-size: 0.875rem;
    cursor: pointer;
    font-family: var(--font-sans);
}

.search-form .search-submit:hover {
    background-color: var(--color-link-hover);
}

/* ==========================================================================
   Pagination
   ========================================================================== */

.pagination {
    margin-top: var(--spacing-2xl);
    display: flex;
    justify-content: center;
    gap: var(--spacing-sm);
}

.pagination .page-numbers {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 2.25rem;
    height: 2.25rem;
    padding: 0 var(--spacing-sm);
    font-size: 0.875rem;
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    color: var(--color-text);
    text-decoration: none;
}

.pagination .page-numbers.current,
.pagination .page-numbers:hover {
    background-color: var(--color-accent);
    color: #ffffff;
    border-color: var(--color-accent);
    text-decoration: none;
}

/* ==========================================================================
   Footer
   ========================================================================== */

.site-footer {
    background-color: var(--color-primary);
    color: #94a3b8;
    padding: var(--spacing-xl) 0;
    margin-top: var(--spacing-2xl);
    font-size: 0.8125rem;
    text-align: center;
}

.site-footer .container {
    max-width: var(--max-width-wide);
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.site-footer a {
    color: #e2e8f0;
}

.site-footer a:hover {
    color: #ffffff;
}

.site-footer p {
    margin-bottom: var(--spacing-xs);
}

/* ==========================================================================
   404 Page
   ========================================================================== */

.error-404 {
    text-align: center;
    padding: var(--spacing-2xl) 0;
}

.error-404 h1 {
    font-size: 4rem;
    font-weight: 800;
    color: var(--color-primary);
    margin-bottom: var(--spacing-md);
}

.error-404 p {
    font-size: 1.125rem;
    color: var(--color-text-light);
    margin-bottom: var(--spacing-xl);
}

/* ==========================================================================
   Search Results
   ========================================================================== */

.search-results-header {
    margin-bottom: var(--spacing-xl);
    padding-bottom: var(--spacing-md);
    border-bottom: 2px solid var(--color-border);
}

.search-results-header h1 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-primary);
}

.search-results-header .search-query {
    color: var(--color-link);
}

.no-results {
    text-align: center;
    padding: var(--spacing-2xl) 0;
}

.no-results h2 {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-md);
}

/* ==========================================================================
   Archive Header
   ========================================================================== */

.archive-header {
    margin-bottom: var(--spacing-xl);
    padding-bottom: var(--spacing-md);
    border-bottom: 2px solid var(--color-border);
}

.archive-header h1 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: var(--spacing-sm);
}

.archive-header .archive-description {
    font-size: 0.9375rem;
    color: var(--color-text-light);
    line-height: 1.7;
}

/* ==========================================================================
   Author Info Box (Single Post)
   ========================================================================== */

.author-info {
    display: flex;
    gap: var(--spacing-md);
    padding: var(--spacing-lg);
    background-color: var(--color-bg-alt);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    margin-top: var(--spacing-xl);
}

.author-info .avatar {
    border-radius: 50%;
    flex-shrink: 0;
}

.author-info .author-name {
    font-size: 1rem;
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: var(--spacing-xs);
}

.author-info .author-bio {
    font-size: 0.875rem;
    color: var(--color-text-light);
    line-height: 1.6;
}

/* ==========================================================================
   Skip to Content (Accessibility)
   ========================================================================== */

.skip-link {
    position: absolute;
    top: -100%;
    left: var(--spacing-md);
    background: var(--color-accent);
    color: #ffffff;
    padding: var(--spacing-sm) var(--spacing-md);
    z-index: 1000;
    font-size: 0.875rem;
    border-radius: 0 0 var(--radius) var(--radius);
}

.skip-link:focus {
    top: 0;
    color: #ffffff;
    text-decoration: none;
}

/* ==========================================================================
   Screen Reader Text (Accessibility)
   ========================================================================== */

.screen-reader-text {
    border: 0;
    clip: rect(1px, 1px, 1px, 1px);
    clip-path: inset(50%);
    height: 1px;
    margin: -1px;
    overflow: hidden;
    padding: 0;
    position: absolute;
    width: 1px;
    word-wrap: normal;
}

/* ==========================================================================
   Responsive Design
   ========================================================================== */

@media screen and (max-width: 768px) {
    .site-content {
        grid-template-columns: 1fr;
        gap: var(--spacing-xl);
        padding: var(--spacing-md) var(--spacing-md);
    }

    .site-header .container {
        flex-direction: column;
        align-items: flex-start;
    }

    .main-navigation ul {
        flex-wrap: wrap;
        gap: var(--spacing-sm) var(--spacing-md);
    }

    .single .entry-title {
        font-size: 1.5rem;
    }

    .entry-title {
        font-size: 1.25rem;
    }

    .entry-content h2 {
        font-size: 1.25rem;
    }

    .entry-content h3 {
        font-size: 1.125rem;
    }

    .entry-meta {
        flex-direction: column;
        gap: var(--spacing-xs);
    }

    .author-info {
        flex-direction: column;
        text-align: center;
    }

    .author-info .avatar {
        margin: 0 auto;
    }

    .related-posts-list {
        grid-template-columns: 1fr;
    }

    .breadcrumb ol {
        flex-wrap: wrap;
    }
}

@media screen and (max-width: 480px) {
    html {
        font-size: 15px;
    }

    .entry-content pre {
        font-size: 0.8125rem;
        padding: var(--spacing-sm);
    }

    .entry-content table {
        font-size: 0.8125rem;
    }

    .entry-content th,
    .entry-content td {
        padding: var(--spacing-xs) var(--spacing-sm);
    }
}

/* ==========================================================================
   Print Styles
   ========================================================================== */

@media print {
    .site-header,
    .sidebar,
    .site-footer,
    .breadcrumb,
    .related-posts,
    .entry-footer,
    .pagination,
    .heading-anchor {
        display: none;
    }

    body {
        font-size: 12pt;
        line-height: 1.5;
        color: #000;
    }

    .site-content {
        display: block;
        max-width: 100%;
    }

    a {
        color: #000;
        text-decoration: underline;
    }

    .entry-content h2,
    .entry-content h3 {
        page-break-after: avoid;
    }

    .entry-content img {
        page-break-inside: avoid;
    }
}