/* ===== CSS Variables ===== */
:root {
    --color-bg: #ffffff;
    --color-bg-alt: #f8f9fa;
    --color-bg-dark: #1a1a2e;
    --color-surface: #ffffff;
    --color-border: #e2e8f0;
    --color-border-light: #edf2f7;

    --color-text: #1a202c;
    --color-text-secondary: #4a5568;
    --color-text-muted: #a0aec0;

    --color-primary: #c72e2e;
    --color-primary-hover: #a82323;
    --color-primary-light: #fee2e2;
    --color-primary-bg: #fef2f2;

    --color-accent: #2b6cb0;
    --color-accent-hover: #2c5282;
    --color-accent-light: #ebf8ff;

    --color-success: #38a169;
    --color-warning: #d69e2e;
    --color-danger: #e53e3e;

    --font-sans: 'Inter', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'SF Mono', 'Fira Code', 'Cascadia Code', monospace;

    --radius: 8px;
    --radius-lg: 12px;
    --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);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.07), 0 2px 4px rgba(0,0,0,0.06);
    --shadow-lg: 0 10px 15px rgba(0,0,0,0.1), 0 4px 6px rgba(0,0,0,0.05);

    --max-width: 1200px;
    --max-width-narrow: 820px;
    --header-height: 64px;
}

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-sans);
    color: var(--color-text);
    background: var(--color-bg);
    line-height: 1.7;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

a {
    color: var(--color-primary);
    text-decoration: none;
    transition: color 0.15s;
}
a:hover {
    color: var(--color-primary-hover);
}

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

/* ===== Layout ===== */
.container {
    width: 100%;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
}
.container-narrow {
    max-width: var(--max-width-narrow);
}

.site-main {
    flex: 1;
}

/* ===== Header ===== */
.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(255,255,255,0.92);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--color-border);
    height: var(--header-height);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
}

/* Logo */
.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--color-text);
    text-decoration: none;
}
.logo:hover { color: var(--color-text); }
.logo-icon {
    width: 36px;
    height: 36px;
    color: var(--color-primary);
}
.logo-img {
    width: 36px;
    height: 36px;
    object-fit: contain;
    display: block;
}
.logo-text {
    display: flex;
    flex-direction: column;
}
.logo-title {
    font-size: 1.15rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    line-height: 1.2;
}
.logo-accent {
    color: var(--color-primary);
}
.logo-subtitle {
    font-size: 0.7rem;
    color: var(--color-text-muted);
    letter-spacing: 0.02em;
    line-height: 1.2;
}

/* Navigation */
.main-nav {
    display: flex;
    align-items: center;
    gap: 4px;
}
.nav-link {
    padding: 8px 14px;
    border-radius: var(--radius);
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--color-text-secondary);
    transition: all 0.15s;
}
.nav-link:hover {
    color: var(--color-text);
    background: var(--color-bg-alt);
}
.admin-link {
    color: var(--color-primary);
    font-weight: 600;
}

/* Nav user (logged-in state) */
.nav-user-wrap {
    position: relative;
}
.nav-user-link {
    display: flex !important;
    align-items: center;
    gap: 8px;
    color: var(--color-text) !important;
    font-weight: 500;
}
.nav-user-link:hover {
    background: var(--color-bg-alt);
}
.nav-user-avatar {
    width: 28px;
    height: 28px;
    border-radius: 50%;
    background: var(--color-primary);
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.75rem;
    text-transform: uppercase;
    flex-shrink: 0;
}
.nav-user-name {
    font-size: 0.85rem;
    max-width: 100px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

/* Dropdown */
.nav-dropdown {
    position: relative;
}
.nav-dropdown .nav-link {
    cursor: pointer;
}
.dropdown-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%);
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
    padding: 6px 0;
    min-width: 140px;
    z-index: 200;
}
.nav-dropdown:hover .dropdown-menu {
    display: block;
}
.dropdown-menu a {
    display: block;
    padding: 8px 16px;
    font-size: 0.85rem;
    color: var(--color-text-secondary);
    transition: all 0.15s;
}
.dropdown-menu a:hover {
    background: var(--color-bg-alt);
    color: var(--color-text);
}

/* Mobile menu */
.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
}
.mobile-menu-btn span {
    display: block;
    width: 22px;
    height: 2px;
    background: var(--color-text);
    border-radius: 2px;
    transition: all 0.2s;
}

.mobile-nav-overlay {
    display: none;
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0,0,0,0.4);
    z-index: 99;
}
.mobile-nav-overlay.active {
    display: block;
}
.mobile-nav {
    background: var(--color-surface);
    padding: 16px;
    display: flex;
    flex-direction: column;
    gap: 4px;
}
.mobile-nav a {
    display: block;
    padding: 12px 16px;
    border-radius: var(--radius);
    font-size: 1rem;
    font-weight: 500;
    color: var(--color-text-secondary);
}
.mobile-nav a:hover {
    background: var(--color-bg-alt);
    color: var(--color-text);
}

@media (max-width: 768px) {
    .main-nav { display: none; }
    .mobile-menu-btn { display: flex; }
}

/* ===== Footer ===== */
.site-footer {
    background: var(--color-bg-dark);
    color: #cbd5e0;
    padding: 48px 0 24px;
    margin-top: 80px;
}
.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1.5fr;
    gap: 40px;
    margin-bottom: 32px;
}
.footer-col h4 {
    color: #fff;
    font-size: 0.95rem;
    margin-bottom: 16px;
}
.footer-col p {
    font-size: 0.85rem;
    line-height: 1.7;
    color: #a0aec0;
}
.footer-col a {
    display: block;
    font-size: 0.85rem;
    color: #a0aec0;
    padding: 4px 0;
    transition: color 0.15s;
}
.footer-col a:hover {
    color: #fff;
}
.footer-bottom {
    border-top: 1px solid rgba(255,255,255,0.08);
    padding-top: 16px;
    text-align: center;
    font-size: 0.8rem;
    color: #718096;
}

.footer-bottom .icp-record {
    margin-top: 6px;
}

.footer-bottom .icp-record a {
    color: #718096;
    text-decoration: none;
}

.footer-bottom .icp-record a:hover {
    color: #a0aec0;
}

@media (max-width: 768px) {
    .footer-grid {
        grid-template-columns: 1fr 1fr;
        gap: 24px;
    }
}
@media (max-width: 480px) {
    .footer-grid {
        grid-template-columns: 1fr;
    }
}

/* ===== Hero ===== */
.hero {
    position: relative;
    padding: 80px 0 60px;
    text-align: center;
    overflow: hidden;
}
.hero-content {
    position: relative;
    z-index: 1;
}
.hero-title {
    font-size: 3rem;
    font-weight: 800;
    letter-spacing: -0.03em;
    line-height: 1.2;
    margin-bottom: 16px;
}
.hero-node {
    color: var(--color-text);
}
.hero-red {
    color: var(--color-primary);
}
.hero-sub {
    display: block;
    font-size: 2rem;
    font-weight: 600;
    color: var(--color-text-secondary);
    margin-top: 4px;
}
.hero-desc {
    font-size: 1.1rem;
    color: var(--color-text-secondary);
    max-width: 560px;
    margin: 0 auto 32px;
    line-height: 1.7;
}
.hero-actions {
    display: flex;
    gap: 12px;
    justify-content: center;
    flex-wrap: wrap;
}
.hero-bg {
    position: absolute;
    inset: 0;
    background:
        radial-gradient(ellipse 80% 60% at 50% 0%, var(--color-primary-bg) 0%, transparent 60%),
        radial-gradient(ellipse 60% 50% at 80% 100%, var(--color-accent-light) 0%, transparent 50%);
    opacity: 0.7;
}

@media (max-width: 640px) {
    .hero { padding: 48px 0 40px; }
    .hero-title { font-size: 2rem; }
    .hero-sub { font-size: 1.3rem; }
    .hero-desc { font-size: 0.95rem; }
}

/* Page hero (subpages) */
.page-hero {
    padding: 48px 0 32px;
    text-align: center;
    background: var(--color-bg-alt);
    border-bottom: 1px solid var(--color-border);
}
.page-hero-title {
    font-size: 2rem;
    font-weight: 700;
    letter-spacing: -0.02em;
}
.page-hero-desc {
    color: var(--color-text-secondary);
    margin-top: 8px;
    font-size: 1rem;
}

/* ===== Buttons ===== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 10px 24px;
    border-radius: var(--radius);
    font-size: 0.9rem;
    font-weight: 600;
    border: none;
    cursor: pointer;
    transition: all 0.15s;
    gap: 6px;
}
.btn-primary {
    background: var(--color-primary);
    color: #fff;
}
.btn-primary:hover {
    background: var(--color-primary-hover);
    color: #fff;
}
.btn-outline {
    background: transparent;
    color: var(--color-primary);
    border: 1.5px solid var(--color-primary);
}
.btn-outline:hover {
    background: var(--color-primary);
    color: #fff;
}
.btn-outline-light {
    background: transparent;
    color: #fff;
    border: 1.5px solid rgba(255,255,255,0.5);
}
.btn-outline-light:hover {
    background: rgba(255,255,255,0.1);
    color: #fff;
}
.btn-sm {
    padding: 6px 14px;
    font-size: 0.8rem;
}
.btn-full {
    width: 100%;
}

/* ===== Stats Bar ===== */
.stats-bar {
    padding: 32px 0;
    border-bottom: 1px solid var(--color-border);
}
.stats-grid {
    display: flex;
    justify-content: center;
    gap: 64px;
}
.stat-item {
    text-align: center;
}
.stat-number {
    display: block;
    font-size: 2rem;
    font-weight: 800;
    color: var(--color-primary);
    line-height: 1;
}
.stat-label {
    display: block;
    font-size: 0.85rem;
    color: var(--color-text-muted);
    margin-top: 4px;
}

@media (max-width: 480px) {
    .stats-grid { gap: 32px; }
    .stat-number { font-size: 1.5rem; }
}

/* ===== Sections ===== */
.section {
    padding: 64px 0;
}
.section-alt {
    background: var(--color-bg-alt);
}
.section-header {
    text-align: center;
    margin-bottom: 40px;
}
.section-title {
    font-size: 1.75rem;
    font-weight: 700;
    letter-spacing: -0.02em;
}
.section-desc {
    color: var(--color-text-secondary);
    margin-top: 8px;
    font-size: 1rem;
}
.section-footer {
    text-align: center;
    margin-top: 32px;
}

/* ===== Chapter Cards ===== */
.chapter-cards {
    display: flex;
    flex-direction: column;
    gap: 8px;
}
.chapter-card {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 16px 20px;
    border-radius: var(--radius);
    border: 1px solid var(--color-border-light);
    background: var(--color-surface);
    transition: all 0.15s;
}
.chapter-card:hover {
    border-color: var(--color-primary);
    box-shadow: var(--shadow-sm);
    transform: translateX(4px);
}
.chapter-order {
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-primary-bg);
    color: var(--color-primary);
    border-radius: var(--radius);
    font-weight: 700;
    font-size: 0.9rem;
    flex-shrink: 0;
}
.chapter-info {
    flex: 1;
    min-width: 0;
}
.chapter-name {
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: 2px;
}
.chapter-desc {
    font-size: 0.8rem;
    color: var(--color-text-muted);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
.chapter-arrow {
    color: var(--color-text-muted);
    font-size: 1.2rem;
    flex-shrink: 0;
    transition: transform 0.15s;
}
.chapter-card:hover .chapter-arrow {
    transform: translateX(4px);
    color: var(--color-primary);
}

/* ===== Service Cards ===== */
.service-cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}
.service-card {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    padding: 28px;
    border-radius: var(--radius-lg);
    border: 1px solid var(--color-border-light);
    background: var(--color-surface);
    transition: all 0.2s;
}
.service-card:hover {
    border-color: var(--color-primary);
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}
.service-icon {
    width: 48px;
    height: 48px;
    color: var(--color-primary);
    margin-bottom: 16px;
}
.service-card h3 {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: 8px;
}
.service-card p {
    font-size: 0.85rem;
    color: var(--color-text-secondary);
    line-height: 1.6;
}

@media (max-width: 768px) {
    .service-cards { grid-template-columns: 1fr; }
}

/* ===== Q&A ===== */
.qa-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
}
.qa-item {
    border: 1px solid var(--color-border-light);
    border-radius: var(--radius-lg);
    padding: 20px;
    background: var(--color-surface);
}
.qa-q, .qa-a {
    display: flex;
    gap: 12px;
    align-items: flex-start;
}
.qa-q {
    margin-bottom: 12px;
}
.qa-badge {
    width: 28px;
    height: 28px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 6px;
    font-weight: 700;
    font-size: 0.8rem;
    flex-shrink: 0;
    background: var(--color-primary-bg);
    color: var(--color-primary);
}
.qa-badge-a {
    background: var(--color-accent-light);
    color: var(--color-accent);
}
.qa-content {
    font-size: 0.9rem;
    line-height: 1.7;
    color: var(--color-text);
}
.qa-a .qa-content {
    color: var(--color-text-secondary);
}
.qa-meta {
    font-size: 0.75rem;
    color: var(--color-text-muted);
    margin-top: 4px;
    display: block;
}

/* Ask form */
.ask-section {
    margin-bottom: 48px;
    padding: 28px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    background: var(--color-bg-alt);
}
.ask-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 20px;
}
.ask-form {
    display: flex;
    flex-direction: column;
    gap: 14px;
}
.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 14px;
}
.form-group {
    display: flex;
    flex-direction: column;
    gap: 6px;
}
.form-group label {
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--color-text-secondary);
}
.form-group input,
.form-group textarea {
    padding: 10px 14px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    font-family: var(--font-sans);
    font-size: 0.9rem;
    color: var(--color-text);
    background: var(--color-surface);
    transition: border-color 0.15s;
}
.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px var(--color-primary-bg);
}
.form-message {
    font-size: 0.85rem;
    padding: 8px 0;
}
.form-message.success { color: var(--color-success); }
.form-message.error { color: var(--color-danger); }

/* Checkbox label */
.checkbox-label {
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    font-size: 0.88rem;
    font-weight: 500;
    color: var(--color-text);
    user-select: none;
}
.checkbox-label input[type="checkbox"] {
    width: 16px;
    height: 16px;
    accent-color: var(--color-primary);
    cursor: pointer;
}
.form-hint {
    display: block;
    font-size: 0.75rem;
    color: var(--color-text-muted);
    margin-top: 4px;
}

/* Pagination */
.pagination {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 16px;
    margin-top: 32px;
}
.page-link {
    padding: 8px 16px;
    border-radius: var(--radius);
    font-size: 0.85rem;
    font-weight: 500;
    border: 1px solid var(--color-border);
    color: var(--color-text-secondary);
}
.page-link:hover {
    border-color: var(--color-primary);
    color: var(--color-primary);
}
.page-info {
    font-size: 0.85rem;
    color: var(--color-text-muted);
}

/* ===== CTA ===== */
.cta-section {
    padding: 64px 0;
    background: var(--color-bg-dark);
    text-align: center;
    color: #fff;
}
.cta-section h2 {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: 8px;
}
.cta-section p {
    color: #a0aec0;
    margin-bottom: 24px;
    font-size: 1rem;
}
.cta-actions {
    display: flex;
    gap: 12px;
    justify-content: center;
    flex-wrap: wrap;
}

/* ===== Docs Layout (Online Documentation) ===== */
.docs-layout {
    display: grid;
    grid-template-columns: 280px 1fr;
    min-height: calc(100vh - var(--header-height));
}

/* Sidebar */
.docs-sidebar {
    border-right: 1px solid var(--color-border);
    background: var(--color-bg-alt);
    height: calc(100vh - var(--header-height));
    position: sticky;
    top: var(--header-height);
    overflow: hidden;
    display: flex;
    flex-direction: column;
}
.docs-sidebar-inner {
    overflow-y: auto;
    padding: 20px 0;
    flex: 1;
    overscroll-behavior: contain;
}
.docs-sidebar-header {
    padding: 0 20px 16px;
    border-bottom: 1px solid var(--color-border);
    margin-bottom: 8px;
}
.docs-home-link {
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 700;
    font-size: 0.92rem;
    color: var(--color-text);
    transition: color 0.15s;
}
.docs-home-link:hover {
    color: var(--color-primary);
}
.docs-home-link svg {
    color: var(--color-primary);
    flex-shrink: 0;
}

/* Outline chapters */
.docs-outline {
    padding: 4px 0;
}
.outline-chapter {
    margin: 0;
}
.outline-chapter-toggle {
    display: flex;
    align-items: center;
    gap: 6px;
    width: 100%;
    padding: 7px 20px;
    border: none;
    background: none;
    cursor: pointer;
    font-family: inherit;
    font-size: 0.84rem;
    font-weight: 600;
    color: var(--color-text);
    text-align: left;
    transition: all 0.15s;
    border-left: 3px solid transparent;
}
.outline-chapter-toggle:hover {
    background: var(--color-surface);
    color: var(--color-primary);
}
.outline-chapter-toggle.expanded {
    color: var(--color-primary);
    border-left-color: var(--color-primary);
}
.toggle-icon {
    font-size: 0.6rem;
    transition: transform 0.2s;
    flex-shrink: 0;
    width: 12px;
    text-align: center;
    color: var(--color-text-muted);
}
.outline-chapter-toggle.expanded .toggle-icon {
    transform: rotate(90deg);
}

/* Sections list */
.outline-sections {
    display: none;
    padding: 2px 0 8px;
}
.outline-sections.expanded {
    display: block;
}

/* Section group (2nd level) */
.outline-section-group {
    margin: 0;
}
.outline-section-toggle {
    display: flex;
    align-items: baseline;
    gap: 4px;
    width: 100%;
    padding: 5px 20px 5px 32px;
    border: none;
    background: none;
    cursor: pointer;
    font-family: inherit;
    font-size: 0.8rem;
    color: var(--color-text-secondary);
    text-align: left;
    transition: all 0.15s;
    border-left: 3px solid transparent;
}
.outline-section-toggle:hover {
    color: var(--color-primary);
    background: var(--color-surface);
}
.toggle-icon-sm {
    font-size: 0.55rem;
    transition: transform 0.2s;
    flex-shrink: 0;
    width: 10px;
    text-align: center;
    color: var(--color-text-muted);
}
.outline-section-toggle.expanded .toggle-icon-sm {
    transform: rotate(90deg);
}

/* Subsection (3rd level) */
.outline-subsections {
    display: none;
}
.outline-subsections.expanded {
    display: block;
}
.outline-subsection-link {
    display: flex;
    align-items: baseline;
    gap: 4px;
    padding: 4px 20px 4px 48px;
    font-size: 0.78rem;
    color: var(--color-text-muted);
    transition: all 0.15s;
    border-left: 3px solid transparent;
}
.outline-subsection-link:hover {
    color: var(--color-primary);
    background: var(--color-surface);
}
.outline-subsection-link.active-section {
    color: var(--color-primary);
    background: var(--color-primary-bg);
    border-left-color: var(--color-primary);
    font-weight: 500;
}
.outline-subsection-num {
    font-weight: 600;
    color: var(--color-text-muted);
    font-size: 0.7rem;
    min-width: 30px;
    flex-shrink: 0;
}
.outline-subsection-link.active-section .outline-subsection-num {
    color: var(--color-primary);
}
.outline-subsection-title {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

/* Keep old section-link for backward compat */
.outline-section-link {
    display: flex;
    align-items: baseline;
    gap: 6px;
    padding: 5px 20px 5px 38px;
    font-size: 0.8rem;
    color: var(--color-text-secondary);
    transition: all 0.15s;
    border-left: 3px solid transparent;
}
.outline-section-link:hover {
    color: var(--color-primary);
    background: var(--color-surface);
}
.outline-section-link.active-section {
    color: var(--color-primary);
    background: var(--color-primary-bg);
    border-left-color: var(--color-primary);
    font-weight: 500;
}
.outline-section-num {
    font-weight: 600;
    color: var(--color-text-muted);
    font-size: 0.72rem;
    min-width: 24px;
    flex-shrink: 0;
}
.outline-section-link.active-section .outline-section-num {
    color: var(--color-primary);
}
.outline-section-title {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

/* Mobile sidebar toggle button */
.docs-sidebar-toggle {
    display: none;
    align-items: center;
    gap: 6px;
    padding: 8px 14px;
    margin: 12px 16px 0;
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    background: var(--color-surface);
    cursor: pointer;
    font-family: inherit;
    font-size: 0.85rem;
    color: var(--color-text-secondary);
    transition: all 0.15s;
}
.docs-sidebar-toggle:hover {
    border-color: var(--color-primary);
    color: var(--color-primary);
}
.docs-sidebar-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.4);
    z-index: 90;
    opacity: 0;
    transition: opacity 0.2s;
}
.docs-sidebar-overlay.visible {
    display: block;
    opacity: 1;
}

/* Content area */
.docs-content {
    padding: 40px 56px;
    max-width: 860px;
    width: 100%;
    margin: 0 auto;
}
.docs-article-header {
    margin-bottom: 36px;
    padding-bottom: 24px;
    border-bottom: 1px solid var(--color-border-light);
}
.docs-article-title {
    font-size: 2rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    margin-bottom: 8px;
    color: var(--color-text);
}
.docs-article-desc {
    color: var(--color-text-secondary);
    font-size: 0.98rem;
    line-height: 1.6;
}
.docs-section {
    margin-bottom: 40px;
    scroll-margin-top: 80px;
}

/* Chapter bottom nav */
.chapter-bottom-nav {
    display: flex;
    justify-content: space-between;
    margin-top: 48px;
    padding-top: 24px;
    border-top: 1px solid var(--color-border-light);
}
.chapter-nav-btn {
    padding: 10px 18px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--color-text-secondary);
    transition: all 0.15s;
}
.chapter-nav-btn:hover {
    border-color: var(--color-primary);
    color: var(--color-primary);
}


/* ===== Access Restriction Notice ===== */
.access-notice {
    margin-top: 48px;
    padding: 36px 40px;
    border: 2px dashed var(--color-border);
    border-radius: var(--radius-lg);
    background: linear-gradient(135deg, var(--color-bg-alt) 0%, var(--color-primary-bg) 100%);
    text-align: center;
}
.access-notice-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 64px;
    height: 64px;
    border-radius: 50%;
    background: var(--color-primary-bg);
    color: var(--color-primary);
    margin-bottom: 16px;
}
.access-notice h3 {
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--color-text);
    margin-bottom: 8px;
}
.access-notice p {
    color: var(--color-text-secondary);
    font-size: 0.92rem;
    margin-bottom: 20px;
    line-height: 1.6;
}
.access-notice-actions {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
}
.access-notice-hint {
    font-size: 0.8rem;
    color: var(--color-text-muted);
}

/* Responsive */
@media (max-width: 900px) {
    .docs-layout {
        grid-template-columns: 1fr;
    }
    .docs-sidebar {
        position: fixed;
        left: 0;
        top: 0;
        height: 100vh;
        z-index: 100;
        transform: translateX(-100%);
        transition: transform 0.25s ease;
        width: 280px;
        box-shadow: var(--shadow-lg);
    }
    .docs-sidebar.open {
        transform: translateX(0);
    }
    .docs-sidebar-toggle {
        display: flex;
    }
    .docs-content {
        padding: 16px 20px 40px;
    }
}

/* ===== Markdown Body ===== */
.markdown-body {
    font-size: 0.95rem;
    line-height: 1.8;
    color: var(--color-text);
}
.markdown-body h1 { font-size: 1.75rem; font-weight: 700; margin: 40px 0 16px; }
.markdown-body h2 { font-size: 1.4rem; font-weight: 700; margin: 36px 0 12px; color: var(--color-text); }
.markdown-body h3 { font-size: 1.15rem; font-weight: 600; margin: 28px 0 10px; color: var(--color-text); }
.markdown-body h4 { font-size: 1rem; font-weight: 600; margin: 20px 0 8px; }
.markdown-body p { margin-bottom: 14px; }
.markdown-body ul, .markdown-body ol { margin: 8px 0 16px 24px; }
.markdown-body li { margin-bottom: 4px; }
.markdown-body strong { font-weight: 600; color: var(--color-text); }
.markdown-body blockquote {
    margin: 16px 0;
    padding: 12px 20px;
    border-left: 3px solid var(--color-primary);
    background: var(--color-primary-bg);
    border-radius: 0 var(--radius) var(--radius) 0;
    color: var(--color-text-secondary);
}
.markdown-body code {
    font-family: var(--font-mono);
    font-size: 0.85em;
    background: var(--color-bg-alt);
    padding: 2px 6px;
    border-radius: 4px;
    color: var(--color-primary);
}
.markdown-body pre {
    margin: 16px 0;
    padding: 16px 20px;
    background: #1e1e2e;
    border-radius: var(--radius);
    overflow-x: auto;
}
.markdown-body pre code {
    background: none;
    color: #cdd6f4;
    padding: 0;
    font-size: 0.85rem;
    line-height: 1.6;
}
.markdown-body table {
    width: 100%;
    border-collapse: collapse;
    margin: 16px 0;
    font-size: 0.9rem;
}
.markdown-body th, .markdown-body td {
    padding: 10px 14px;
    border: 1px solid var(--color-border);
    text-align: left;
}
.markdown-body th {
    background: var(--color-bg-alt);
    font-weight: 600;
}
.markdown-body hr {
    border: none;
    border-top: 1px solid var(--color-border-light);
    margin: 32px 0;
}

/* ===== Service CTA ===== */
.service-cta {
    margin-top: 40px;
    padding: 28px;
    background: var(--color-primary-bg);
    border-radius: var(--radius-lg);
    text-align: center;
}
.service-cta h3 {
    font-size: 1.15rem;
    font-weight: 600;
    margin-bottom: 8px;
}
.service-cta p {
    color: var(--color-text-secondary);
    margin-bottom: 16px;
}

/* ===== Login ===== */
.login-card {
    max-width: 400px;
    margin: 40px auto;
    padding: 32px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    background: var(--color-surface);
}
.login-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 24px;
    text-align: center;
}
.login-form {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

/* ===== Admin ===== */
.admin-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 28px;
}
.admin-header h1 {
    font-size: 1.75rem;
    font-weight: 700;
}
.admin-actions {
    display: flex;
    align-items: center;
    gap: 12px;
}
.admin-user {
    font-size: 0.85rem;
    color: var(--color-text-secondary);
    font-weight: 500;
}

.admin-tabs {
    display: flex;
    gap: 4px;
    border-bottom: 2px solid var(--color-border-light);
    margin-bottom: 28px;
}
.admin-tab {
    padding: 10px 20px;
    border: none;
    background: none;
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--color-text-muted);
    cursor: pointer;
    border-bottom: 2px solid transparent;
    margin-bottom: -2px;
    transition: all 0.15s;
}
.admin-tab.active {
    color: var(--color-primary);
    border-bottom-color: var(--color-primary);
}
.admin-tab:hover {
    color: var(--color-text);
}

.admin-tab-content {
    display: none;
}
.admin-tab-content.active {
    display: block;
}

.admin-qa-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
}
.admin-qa-item {
    border: 1px solid var(--color-border-light);
    border-radius: var(--radius-lg);
    padding: 20px;
    background: var(--color-surface);
}
.admin-qa-item.pending {
    border-left: 3px solid var(--color-warning);
}
.admin-qa-item.answered {
    border-left: 3px solid var(--color-success);
}
.admin-qa-header {
    margin-bottom: 10px;
}
.admin-qa-meta {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 12px;
    font-size: 0.82rem;
    color: var(--color-text-muted);
}
.admin-qa-meta strong {
    color: var(--color-text);
}
.status-badge {
    padding: 2px 10px;
    border-radius: 12px;
    font-size: 0.75rem;
    font-weight: 600;
}
.status-waiting {
    background: #fefcbf;
    color: #975a16;
}
.status-done {
    background: #c6f6d5;
    color: #276749;
}
.admin-qa-q {
    font-size: 0.9rem;
    line-height: 1.7;
    color: var(--color-text);
    margin-bottom: 12px;
    padding: 12px;
    background: var(--color-bg-alt);
    border-radius: var(--radius);
}
.admin-qa-a {
    font-size: 0.85rem;
    color: var(--color-text-secondary);
    margin-bottom: 12px;
}
.admin-qa-reply textarea {
    width: 100%;
    padding: 10px 14px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    font-family: var(--font-sans);
    font-size: 0.85rem;
    resize: vertical;
}
.admin-qa-reply textarea:focus {
    outline: none;
    border-color: var(--color-primary);
}
.answer-actions {
    display: flex;
    gap: 8px;
    margin-top: 8px;
}

/* ===== Empty State ===== */
.empty-state {
    text-align: center;
    padding: 48px 24px;
    color: var(--color-text-muted);
}
.empty-state p {
    margin-bottom: 16px;
    font-size: 1rem;
}

/* ===== Utility ===== */
.text-center { text-align: center; }
.mt-16 { margin-top: 16px; }
.mt-24 { margin-top: 24px; }
.mt-32 { margin-top: 32px; }