/* =====================================
   CSS Reset & Base Styles
   ===================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Colors - Navbar matches main site */
    --primary-color: #6366F1; /* Matches main site navbar */
    --primary-dark: #4F46E5;
    --secondary-color: #EC4899; /* For active nav links */
    --text-primary: #1F2937; /* Matches main site */
    --text-secondary: #6b7280;
    --text-muted: #9ca3af;
    --text-inverse: #FFFFFF;
    --border-color: #1F2937; /* Matches main site navbar border */
    --border-width: 3px; /* Matches main site navbar */
    --shadow-offset: 6px; /* Matches main site navbar */
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-tertiary: #f3f4f6;
    --accent-blue: #dbeafe;
    --accent-green: #d1fae5;
    --accent-yellow: #fef3c7;
    --code-bg: #1e1e1e;
    --code-text: #d4d4d4;
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    
    /* Layout */
    --header-height: 60px;
    --header-tabs-height: 48px;
    --mlp-navbar-height: 85px; /* Navbar: 20px padding top + ~35px content + 20px padding bottom + 3px border + shadow */
    --header-total-height: calc(var(--mlp-navbar-height) + var(--header-tabs-height));
    --sidebar-width: 280px;
    --toc-width: 240px;
    --content-max-width: 900px;
    
    /* Typography */
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-mono: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', Consolas, 'Courier New', monospace;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', 'Helvetica Neue', Arial, sans-serif; /* Match main site */
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-secondary);
    font-size: 16px;
    font-weight: 500; /* Match main site */
}

/* =====================================
   Layout Structure
   ===================================== */
.page-container {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

.header {
    /* Removed - using MLP navbar instead */
    display: none;
}

/* MLP Navbar Styles - ensure it matches main site exactly */
/* Override any conflicting styles to match root styles.css exactly */
.mlp-navbar-wrapper.navbar,
.navbar.mlp-navbar-wrapper {
    background: var(--primary-color);
    border-bottom: var(--border-width) solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 200; /* Higher than header-tabs to stay on top */
    box-shadow: var(--shadow-offset) var(--shadow-offset) 0 var(--border-color);
}

.navbar.mlp-navbar-wrapper .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px;
}

.navbar.mlp-navbar-wrapper .nav-brand {
    font-size: 24px !important;
    font-weight: 800 !important;
    color: var(--text-primary);
    text-decoration: none;
    letter-spacing: -0.5px;
    transition: transform 0.2s ease;
}

.navbar.mlp-navbar-wrapper .nav-brand:hover {
    transform: translateY(-2px);
}

.navbar.mlp-navbar-wrapper .nav-menu {
    display: flex;
    list-style: none;
    gap: 8px;
}

.navbar.mlp-navbar-wrapper .nav-link {
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 600 !important;
    font-size: 15px !important;
    padding: 10px 18px !important;
    border: var(--border-width) solid var(--border-color);
    background: var(--bg-primary);
    transition: all 0.2s ease;
    box-shadow: 3px 3px 0 var(--border-color);
}

.navbar.mlp-navbar-wrapper .nav-link:hover {
    transform: translate(2px, 2px);
    box-shadow: 2px 2px 0 var(--border-color);
    text-decoration: none !important; /* Remove underline on hover */
}

.navbar.mlp-navbar-wrapper .nav-link.active {
    background: var(--secondary-color);
    color: var(--text-primary);
}

.header-content {
    max-width: 1920px;
    margin: 0 auto;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 var(--spacing-xl);
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    text-decoration: none;
}

.logo-icon {
    font-size: 1.5rem;
}

.header-nav {
    display: flex;
    gap: var(--spacing-xl);
}

.header-nav a {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
}

.header-nav a:hover,
.header-nav a.active {
    color: var(--primary-color);
}

/* Header Tabs */
.header-tabs {
    display: flex !important; /* Ensure tabs are always visible */
    gap: 0;
    border-bottom: 1px solid var(--border-color);
    background: var(--bg-primary);
    padding: 0 var(--spacing-xl);
    max-width: 100%; /* Full width for left alignment */
    margin: 0; /* Remove auto margin that centers content */
    position: sticky;
    top: var(--mlp-navbar-height); /* MLP navbar height */
    z-index: 150;
    justify-content: flex-start !important; /* Force left align tabs */
    min-height: 48px; /* Ensure tabs are always visible */
    align-items: center; /* Vertically center tab links */
}

.tab-link {
    padding: var(--spacing-md) var(--spacing-lg);
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 700 !important; /* Bold */
    font-size: 0.9375rem;
    border-bottom: 2px solid transparent;
    transition: all 0.2s;
    position: relative;
    top: 1px;
}

.tab-link:hover {
    color: var(--primary-color);
    background: var(--bg-secondary);
    border-bottom-color: var(--primary-color) !important; /* Purple underline matching active tab */
}

.tab-link.active {
    color: var(--primary-color);
    border-bottom-color: var(--primary-color);
}

/* Main Wrapper */
.main-wrapper {
    display: flex;
    margin-top: 0;
    min-height: calc(100vh - var(--mlp-navbar-height) - var(--header-tabs-height));
    align-items: flex-start;
}

/* =====================================
   Sidebar Navigation
   ===================================== */
.sidebar {
    position: fixed;
    top: calc(var(--mlp-navbar-height) + var(--header-tabs-height) + 12px); /* MLP navbar + header-tabs + offset for scrollbar */
    left: 0;
    width: var(--sidebar-width);
    height: calc(100vh - var(--mlp-navbar-height) - var(--header-tabs-height) - 12px); /* Adjust height to account for offset */
    background: var(--bg-primary);
    border-right: 1px solid var(--border-color);
    overflow-y: auto;
    padding: var(--spacing-xl) 0;
}

.sidebar-nav {
    padding: 0 var(--spacing-lg);
}

.nav-section {
    margin-bottom: var(--spacing-xl);
}

.nav-section-title {
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
}

.nav-subsection {
    margin-bottom: var(--spacing-md);
}

.nav-subsection:last-child {
    margin-bottom: 0;
}

.nav-subsection-title {
    font-size: 0.6875rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
    margin-bottom: var(--spacing-xs);
    margin-top: var(--spacing-sm);
    padding-left: var(--spacing-sm);
}

.nav-list {
    list-style: none;
}

.nav-list li {
    margin-bottom: var(--spacing-xs);
}

.nav-list a {
    display: block;
    padding: var(--spacing-sm) var(--spacing-md);
    color: var(--text-primary);
    text-decoration: none;
    border-radius: 6px;
    font-size: 0.9375rem;
    transition: background-color 0.2s, color 0.2s;
}

.nav-list a:hover {
    background-color: var(--bg-tertiary);
    color: var(--primary-color);
}

.nav-list a.active {
    background-color: var(--accent-blue);
    color: var(--primary-color);
    font-weight: 500;
}

/* =====================================
   Main Content Area
   ===================================== */
.content {
    flex: 1;
    margin-left: var(--sidebar-width);
    margin-right: var(--toc-width);
    padding: var(--spacing-2xl);
    max-width: var(--content-max-width);
}

.article {
    background: var(--bg-primary);
    padding: var(--spacing-2xl);
    border-radius: 8px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

.page-title {
    font-size: 2.5rem;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: var(--spacing-lg);
    color: var(--text-primary);
}

.lead {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xl);
    line-height: 1.7;
}

/* Typography */
.article h2 {
    font-size: 1.875rem;
    font-weight: 700;
    margin-top: var(--spacing-2xl);
    margin-bottom: var(--spacing-lg);
    color: var(--text-primary);
    scroll-margin-top: calc(var(--header-total-height) + 2rem);
}

.article h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-top: var(--spacing-xl);
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
    scroll-margin-top: calc(var(--header-total-height) + 2rem);
}

.article h4 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-top: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
    scroll-margin-top: calc(var(--header-total-height) + 2rem);
}

.article p {
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
}

.article ul,
.article ol {
    margin-bottom: var(--spacing-md);
    padding-left: var(--spacing-xl);
}

.article li {
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

.article a {
    color: var(--primary-color);
    text-decoration: none;
    border-bottom: 1px solid transparent;
    transition: border-color 0.2s;
}

.article a:hover {
    border-bottom-color: var(--primary-color);
}

/* Code Blocks */
code {
    background: var(--bg-tertiary);
    padding: 0.2em 0.4em;
    border-radius: 4px;
    font-family: var(--font-mono);
    font-size: 0.875em;
    color: #e83e8c;
}

.code-block-wrapper {
    position: relative;
    margin: var(--spacing-lg) 0;
}

pre {
    background: var(--code-bg);
    color: var(--code-text);
    padding: var(--spacing-lg);
    border-radius: 8px;
    overflow-x: auto;
    margin: 0;
    font-family: var(--font-mono);
    font-size: 0.875rem;
    line-height: 1.6;
}

pre code {
    background: none;
    padding: 0;
    color: inherit;
    font-size: inherit;
}

.copy-code-btn {
    position: absolute;
    top: var(--spacing-sm);
    right: var(--spacing-sm);
    padding: 0.375rem 0.75rem;
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 4px;
    color: var(--code-text);
    font-size: 0.75rem;
    font-family: var(--font-sans);
    cursor: pointer;
    transition: all 0.2s;
}

.copy-code-btn:hover {
    background: rgba(255, 255, 255, 0.2);
}

.copy-code-btn.copied {
    background: #10b981;
    border-color: #10b981;
    color: white;
}

/* Divider */
.divider {
    border: 0;
    border-top: 1px solid var(--border-color);
    margin: var(--spacing-2xl) 0;
}

/* =====================================
   Cards & Components
   ===================================== */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
    margin: var(--spacing-xl) 0;
}

.feature-card {
    display: block;
    padding: var(--spacing-xl);
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-bottom: 2px solid var(--border-color) !important; /* More prominent bottom border */
    border-radius: 8px;
    text-decoration: none;
    transition: all 0.2s;
}

.feature-card:hover {
    border-color: var(--primary-color);
    border-bottom: 2px solid var(--primary-color) !important; /* Maintain bottom border on hover */
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.1);
    transform: translateY(-2px);
}

.feature-icon {
    font-size: 2rem;
    margin-bottom: var(--spacing-md);
}

.feature-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin: 0 0 var(--spacing-sm) 0;
}

.feature-card p {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
    font-size: 0.9375rem;
}

.card-link {
    color: var(--primary-color);
    font-weight: 500;
    font-size: 0.9375rem;
}

/* Platform Cards */
.platform-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
    margin: var(--spacing-xl) 0;
}

.platform-card {
    padding: var(--spacing-xl);
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-bottom: 2px solid var(--border-color) !important; /* More prominent bottom border */
    border-radius: 8px;
}

.platform-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

.platform-icon {
    font-size: 2rem;
}

.platform-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin: 0;
}

.platform-card p {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
    font-size: 0.9375rem;
}

.platform-card ul {
    margin-bottom: var(--spacing-lg);
}

.platform-card .btn {
    display: block;
    width: 100%;
    margin-top: var(--spacing-md);
    text-align: center;
    box-sizing: border-box;
}

.platform-card .btn-secondary {
    background: white;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

.platform-card .btn-secondary:hover {
    background: var(--primary-color);
    color: white;
}

.platform-tags {
    display: flex;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
}

.tag {
    padding: 0.25rem 0.625rem;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-bottom: 2px solid var(--border-color); /* More prominent bottom border */
    border-radius: 4px;
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--text-secondary);
}

.platform-link {
    color: var(--primary-color);
    font-weight: 500;
    text-decoration: none;
    font-size: 0.9375rem;
}

.platform-link:hover {
    text-decoration: underline;
}

/* Alerts */
.alert {
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: 8px;
    margin: var(--spacing-lg) 0;
    border-left: 4px solid;
    border-bottom: 2px solid; /* Bottom border for alerts */
}

.alert-info {
    background: var(--accent-blue);
    border-color: var(--primary-color);
    border-bottom-color: var(--primary-color); /* Match left border color */
    color: #1e40af;
}

.alert-success {
    background: var(--accent-green);
    border-color: #10b981;
    border-bottom-color: #10b981; /* Match left border color */
    color: #065f46;
}

.alert-warning {
    background: var(--accent-yellow);
    border-color: #f59e0b;
    border-bottom-color: #f59e0b; /* Match left border color */
    color: #92400e;
}

.alert strong {
    font-weight: 600;
}

/* Lists */
.popular-articles {
    list-style: decimal;
    padding-left: var(--spacing-xl);
}

.popular-articles li {
    margin-bottom: var(--spacing-md);
}

.next-steps {
    list-style: none;
    padding-left: 0;
}

.next-steps li {
    padding-left: 2rem;
    margin-bottom: var(--spacing-md);
}

/* =====================================
   Table of Contents (Right Sidebar)
   ===================================== */
.toc {
    width: var(--toc-width);
    align-self: stretch;
    position: relative;
}

.toc-content {
    position: -webkit-sticky;
    position: sticky;
    top: calc(var(--header-total-height) + var(--spacing-2xl));
    max-height: calc(100vh - var(--header-total-height) - var(--spacing-2xl));
    overflow-y: auto;
    padding: var(--spacing-2xl) var(--spacing-lg);
    background: var(--bg-primary);
    border-left: 1px solid var(--border-color);
}

.toc-title {
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
}

.toc-list {
    list-style: none;
}

.toc-list li {
    margin-bottom: var(--spacing-sm);
}

.toc-list a {
    display: block;
    padding: var(--spacing-xs) 0;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.875rem;
    transition: color 0.2s;
    border-left: 2px solid transparent;
    padding-left: var(--spacing-md);
    margin-left: calc(var(--spacing-md) * -1);
}

.toc-list a:hover,
.toc-list a.active {
    color: var(--primary-color);
    border-left-color: var(--primary-color);
}

/* =====================================
   Page Navigation
   ===================================== */
.page-nav {
    display: flex;
    justify-content: space-between;
    gap: var(--spacing-lg);
    margin-top: var(--spacing-2xl);
    padding-top: var(--spacing-xl);
    border-top: 1px solid var(--border-color);
}

.page-nav-prev,
.page-nav-next {
    display: flex;
    flex-direction: column;
    padding: var(--spacing-lg);
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-bottom: 2px solid var(--border-color); /* More prominent bottom border */
    border-radius: 8px;
    text-decoration: none;
    transition: all 0.2s;
    flex: 1;
}

.page-nav-prev {
    align-items: flex-start;
}

.page-nav-next {
    align-items: flex-end;
}

.page-nav-prev:hover,
.page-nav-next:hover {
    border-color: var(--primary-color);
    background: var(--bg-primary);
}

.page-nav-label {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xs);
}

.page-nav-title {
    font-weight: 500;
    color: var(--primary-color);
}

/* =====================================
   Footer
   ===================================== */
.footer {
    background: var(--bg-primary);
    border-top: 1px solid var(--border-color);
    padding: var(--spacing-xl);
    margin-top: auto;
}

.footer-content {
    max-width: 1920px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: var(--text-secondary);
    font-size: 0.875rem;
    padding-left: var(--sidebar-width);
    padding-right: var(--spacing-xl);
}

.footer-links {
    display: flex;
    gap: var(--spacing-md);
    align-items: center;
}

.footer-links a {
    color: var(--text-secondary);
    text-decoration: none;
    transition: color 0.2s;
}

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

/* =====================================
   Tables
   ===================================== */
table {
    width: 100%;
    border-collapse: collapse;
    margin: var(--spacing-lg) 0;
    font-size: 0.9375rem;
}

thead {
    background: var(--bg-secondary);
}

th {
    padding: var(--spacing-md);
    text-align: left;
    font-weight: 600;
    color: var(--text-primary);
    border-bottom: 2px solid var(--border-color);
}

td {
    padding: var(--spacing-md);
    border-bottom: 1px solid var(--border-color);
    color: var(--text-primary);
}

tr:hover {
    background: var(--bg-secondary);
}

/* =====================================
   Mobile & Responsive
   ===================================== */

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-primary);
    padding: 0.5rem;
    margin-right: var(--spacing-md);
}

.mobile-menu-btn.active {
    color: var(--primary-color);
}

.external-icon {
    font-size: 0.75em;
    opacity: 0.6;
    margin-left: 0.25em;
}

.search-container {
    padding: 0 var(--spacing-lg) var(--spacing-lg);
}

.search-input {
    width: 100%;
    max-width: 320px;
    padding: var(--spacing-sm) var(--spacing-md);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-family: var(--font-sans);
    font-size: 0.9375rem;
    transition: border-color 0.2s;
}

.search-input:focus {
    outline: none;
    border-color: var(--primary-color);
}

/* =====================================
   Responsive Design
   ===================================== */
@media (max-width: 1400px) {
    .toc {
        display: none;
    }
    
    .content {
        margin-right: 0;
        max-width: 100%;
    }
}

@media (max-width: 1024px) {
    .mobile-menu-btn {
        display: block;
    }

    .sidebar {
        transform: translateX(-100%);
        transition: transform 0.3s;
        z-index: 50;
        box-shadow: 2px 0 8px rgba(0, 0, 0, 0.1);
    }
    
    .sidebar.open {
        transform: translateX(0);
    }
    
    .content {
        margin-left: 0;
        padding: var(--spacing-lg);
    }
    
    .article {
        padding: var(--spacing-lg);
    }
    
    .footer-content {
        padding-left: 0;
    }
}

@media (max-width: 768px) {
    .page-title {
        font-size: 2rem;
    }
    
    .article h2 {
        font-size: 1.5rem;
    }
    
    .article h3 {
        font-size: 1.25rem;
    }
    
    .header-content {
        padding: 0 var(--spacing-lg);
    }
    
    .card-grid,
    .platform-cards {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        flex-direction: column;
        gap: var(--spacing-md);
        text-align: center;
    }
}

/* =====================================
   Flow Diagram & Process Visualization
   ===================================== */
.flow-diagram {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-xl);
    background: var(--bg-secondary);
    border-radius: 8px;
    margin: var(--spacing-xl) 0;
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

.flow-step {
    flex: 1;
    min-width: 150px;
    padding: var(--spacing-lg);
    background: var(--bg-primary);
    border: 2px solid var(--primary-color);
    border-radius: 8px;
    text-align: center;
    font-size: 0.9375rem;
}

.flow-arrow {
    font-size: 1.5rem;
    color: var(--primary-color);
    font-weight: bold;
}

@media (max-width: 768px) {
    .flow-diagram {
        flex-direction: column;
    }
    
    .flow-arrow {
        transform: rotate(90deg);
    }
}

/* =====================================
   Buttons
   ===================================== */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    background: var(--primary-color);
    color: white;
    text-decoration: none;
    border-radius: 6px;
    font-weight: 500;
    transition: all 0.2s;
    border: none;
    cursor: pointer;
    font-size: 1rem;
    text-align: center;
}

.btn:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
    box-shadow: 0 4px 8px rgba(37, 99, 235, 0.2);
}

.btn-secondary {
    background: var(--bg-primary);
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

.btn-secondary:hover {
    background: var(--primary-color);
    color: white;
}

/* =====================================
   Utility Classes
   ===================================== */
.text-center {
    text-align: center;
}

.mt-0 { margin-top: 0; }
.mt-1 { margin-top: var(--spacing-md); }
.mt-2 { margin-top: var(--spacing-lg); }
.mt-3 { margin-top: var(--spacing-xl); }

.mb-0 { margin-bottom: 0; }
.mb-1 { margin-bottom: var(--spacing-md); }
.mb-2 { margin-bottom: var(--spacing-lg); }
.mb-3 { margin-bottom: var(--spacing-xl); }