/**
 * Atlas Market Protocol - Main Stylesheet
 * Dark theme design system
 * Version: 1.0.0
 */

/* ===================================================================
   CSS CUSTOM PROPERTIES (Design Tokens)
   =================================================================== */

:root {
    /* Brand Colors */
    --color-primary: #3b82f6;
    --color-primary-dark: #2563eb;
    --color-primary-light: #60a5fa;
    --color-secondary: #8b5cf6;
    --color-accent: #10b981;

    /* Semantic Colors */
    --color-success: #10b981;
    --color-warning: #f59e0b;
    --color-danger: #ef4444;
    --color-info: #3b82f6;

    /* Dark Theme Background Colors */
    --color-bg-primary: #0f172a;
    --color-bg-secondary: #1e293b;
    --color-bg-tertiary: #334155;
    --color-bg-elevated: #475569;

    /* Text Colors */
    --color-text-primary: #f1f5f9;
    --color-text-secondary: #cbd5e1;
    --color-text-tertiary: #94a3b8;
    --color-text-muted: #64748b;

    /* Border Colors */
    --color-border: #475569;
    --color-border-light: #64748b;

    /* Typography */
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-mono: 'Fira Code', 'Courier New', monospace;
    --font-size-base: 16px;
    --line-height-base: 1.6;

    /* Spacing Scale */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --spacing-3xl: 4rem;
    --spacing-4xl: 6rem;

    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --radius-full: 9999px;

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.6);

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 350ms ease;

    /* Container Widths */
    --container-sm: 640px;
    --container-md: 768px;
    --container-lg: 1024px;
    --container-xl: 1280px;
    --container-2xl: 1536px;

    /* Header Height */
    --header-height: 80px;
}

/* ===================================================================
   RESET & BASE STYLES
   =================================================================== */

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

html {
    font-size: var(--font-size-base);
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    font-size: 1rem;
    line-height: var(--line-height-base);
    color: var(--color-text-primary);
    background-color: var(--color-bg-primary);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* SVG Default Styles */
svg {
    display: inline-block;
    vertical-align: middle;
    max-width: 100%;
    max-height: 100%;
}

/* ===================================================================
   TYPOGRAPHY
   =================================================================== */

h1, h2, h3, h4, h5, h6 {
    margin-bottom: var(--spacing-md);
    font-weight: 700;
    line-height: 1.2;
    color: var(--color-text-primary);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.75rem; }
h4 { font-size: 1.5rem; }
h5 { font-size: 1.25rem; }
h6 { font-size: 1.125rem; }

p {
    margin-bottom: var(--spacing-md);
    color: var(--color-text-secondary);
}

a {
    color: var(--color-primary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

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

strong {
    font-weight: 600;
    color: var(--color-text-primary);
}

code {
    padding: var(--spacing-xs) var(--spacing-sm);
    background-color: var(--color-bg-tertiary);
    border-radius: var(--radius-sm);
    font-family: var(--font-mono);
    font-size: 0.875em;
    color: var(--color-primary-light);
}

pre {
    padding: var(--spacing-md);
    background-color: var(--color-bg-secondary);
    border-radius: var(--radius-md);
    border-left: 3px solid var(--color-primary);
    overflow-x: auto;
    margin-bottom: var(--spacing-lg);
}

pre code {
    background: none;
    padding: 0;
}

ul, ol {
    margin-bottom: var(--spacing-lg);
    padding-left: var(--spacing-xl);
    color: var(--color-text-secondary);
}

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

.lead {
    font-size: 1.25rem;
    line-height: 1.7;
    color: var(--color-text-secondary);
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}

/* ===================================================================
   LAYOUT
   =================================================================== */

.container {
    max-width: var(--container-xl);
    margin-left: auto;
    margin-right: auto;
    padding-left: var(--spacing-lg);
    padding-right: var(--spacing-lg);
}

.main-content {
    min-height: calc(100vh - var(--header-height));
}

/* ===================================================================
   HEADER & NAVIGATION
   =================================================================== */

.site-header {
    position: sticky;
    top: 0;
    z-index: 1000;
    background-color: rgba(15, 23, 42, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--color-border);
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: var(--header-height);
}

.site-logo {
    display: flex;
    align-items: center;
}

.logo-link {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    color: var(--color-text-primary);
    font-size: 1.25rem;
    font-weight: 700;
    transition: color var(--transition-fast);
}

.logo-link:hover {
    color: var(--color-primary);
}

.logo-icon {
    width: 32px;
    height: 32px;
    color: var(--color-primary);
}

.logo-text strong {
    color: var(--color-primary);
}

.main-nav {
    display: none;
}

@media (min-width: 768px) {
    .main-nav {
        display: block;
    }
}

.nav-list {
    display: flex;
    gap: var(--spacing-xl);
    list-style: none;
    margin: 0;
    padding: 0;
}

.nav-link {
    display: block;
    padding: var(--spacing-sm) 0;
    color: var(--color-text-secondary);
    font-weight: 500;
    position: relative;
    transition: color var(--transition-fast);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--color-primary);
    transition: width var(--transition-base);
}

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

.nav-link.active::after {
    width: 100%;
}

/* Mobile Menu */
.mobile-menu-toggle {
    display: flex;
    flex-direction: column;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: none;
    border: none;
    cursor: pointer;
}

@media (min-width: 768px) {
    .mobile-menu-toggle {
        display: none;
    }
}

.hamburger {
    width: 24px;
    height: 2px;
    background-color: var(--color-text-primary);
    position: relative;
    transition: background-color var(--transition-fast);
}

.hamburger::before,
.hamburger::after {
    content: '';
    position: absolute;
    width: 100%;
    height: 2px;
    background-color: var(--color-text-primary);
    transition: transform var(--transition-base);
}

.hamburger::before {
    top: -8px;
}

.hamburger::after {
    bottom: -8px;
}

/* Security Notice */
.security-notice {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    background-color: rgba(59, 130, 246, 0.1);
    border-top: 1px solid rgba(59, 130, 246, 0.2);
    font-size: 0.875rem;
}

.notice-icon {
    width: 20px;
    height: 20px;
    color: var(--color-primary);
    flex-shrink: 0;
}

.notice-text {
    color: var(--color-text-secondary);
}

/* ===================================================================
   FOOTER
   =================================================================== */

.site-footer {
    margin-top: var(--spacing-4xl);
    padding-top: var(--spacing-3xl);
    padding-bottom: var(--spacing-xl);
    background-color: var(--color-bg-secondary);
    border-top: 1px solid var(--color-border);
}

.footer-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-2xl);
}

@media (min-width: 768px) {
    .footer-grid {
        grid-template-columns: 2fr 1fr 1fr 1fr;
    }
}

.footer-heading {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-md);
    color: var(--color-text-primary);
}

.footer-description {
    color: var(--color-text-tertiary);
    line-height: 1.7;
}

.footer-established {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-md);
    font-size: 0.875rem;
    color: var(--color-text-muted);
}

.footer-established .icon {
    width: 16px;
    height: 16px;
}

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

.footer-links li {
    margin-bottom: var(--spacing-sm);
}

.footer-links a {
    color: var(--color-text-tertiary);
    transition: color var(--transition-fast);
}

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

.footer-bottom {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-md);
    padding-top: var(--spacing-xl);
    border-top: 1px solid var(--color-border);
    font-size: 0.875rem;
}

@media (min-width: 768px) {
    .footer-bottom {
        flex-direction: row;
        justify-content: space-between;
    }
}

.footer-copyright {
    color: var(--color-text-muted);
}

.footer-legal {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    color: var(--color-text-tertiary);
}

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

.footer-disclaimer {
    margin-top: var(--spacing-xl);
    padding: var(--spacing-lg);
    background-color: rgba(239, 68, 68, 0.1);
    border-left: 3px solid var(--color-danger);
    border-radius: var(--radius-md);
}

.disclaimer-heading {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 1rem;
    margin-bottom: var(--spacing-md);
    color: var(--color-danger);
}

.disclaimer-heading .icon {
    width: 20px;
    height: 20px;
}

.disclaimer-text {
    font-size: 0.875rem;
    line-height: 1.6;
    color: var(--color-text-tertiary);
}

/* Back to Top Button */
.back-to-top {
    position: fixed;
    bottom: var(--spacing-xl);
    right: var(--spacing-xl);
    width: 48px;
    height: 48px;
    border-radius: var(--radius-full);
    background-color: var(--color-primary);
    border: none;
    cursor: pointer;
    display: none;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-lg);
    transition: all var(--transition-base);
}

.back-to-top:hover {
    background-color: var(--color-primary-dark);
    transform: translateY(-2px);
}

.back-to-top.visible {
    display: flex;
}

.back-to-top svg {
    width: 24px;
    height: 24px;
    color: white;
}

/* ===================================================================
   BUTTONS
   =================================================================== */

.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: 1rem;
    font-weight: 500;
    border-radius: var(--radius-md);
    border: none;
    cursor: pointer;
    transition: all var(--transition-base);
    text-decoration: none;
}

.btn .icon {
    width: 20px;
    height: 20px;
}

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

.btn-primary:hover {
    background-color: var(--color-primary-dark);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background-color: var(--color-bg-tertiary);
    color: var(--color-text-primary);
}

.btn-secondary:hover {
    background-color: var(--color-bg-elevated);
}

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

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

.btn-large {
    padding: var(--spacing-lg) var(--spacing-2xl);
    font-size: 1.125rem;
}

/* ===================================================================
   ICONS
   =================================================================== */

.icon {
    width: 24px;
    height: 24px;
    stroke-width: 2;
}

/* ===================================================================
   HERO SECTION
   =================================================================== */

.hero {
    padding: var(--spacing-4xl) 0;
    text-align: center;
    background: linear-gradient(180deg, var(--color-bg-secondary) 0%, var(--color-bg-primary) 100%);
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
}

.hero-title {
    font-size: 3rem;
    margin-bottom: var(--spacing-md);
    line-height: 1.1;
}

.title-accent {
    display: block;
    color: var(--color-primary);
}

.hero-subtitle {
    font-size: 1.5rem;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-md);
}

.hero-tagline {
    font-size: 1.125rem;
    color: var(--color-text-tertiary);
    margin-bottom: var(--spacing-2xl);
}

.hero-cta {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    flex-wrap: wrap;
}

/* ===================================================================
   STATS SECTION
   =================================================================== */

.stats-section {
    padding: var(--spacing-3xl) 0;
    background-color: var(--color-bg-secondary);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-xl);
}

.stat-card {
    text-align: center;
    padding: var(--spacing-xl);
}

.stat-number {
    font-size: 3rem;
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: var(--spacing-sm);
}

.stat-suffix {
    font-size: 2rem;
    color: var(--color-primary-light);
}

.stat-label {
    font-size: 1rem;
    color: var(--color-text-tertiary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* ===================================================================
   SECTIONS
   =================================================================== */

.features-section,
.trust-section,
.guides-section,
.faq-section,
.updates-section,
.cta-section,
.content-section {
    padding: var(--spacing-4xl) 0;
}

.bg-alt {
    background-color: var(--color-bg-secondary);
}

.section-header {
    text-align: center;
    max-width: 800px;
    margin: 0 auto var(--spacing-3xl);
}

.section-title {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-md);
}

.section-description {
    font-size: 1.125rem;
    color: var(--color-text-tertiary);
}

.section-cta {
    margin-top: var(--spacing-3xl);
    text-align: center;
}

/* ===================================================================
   FEATURE CARDS
   =================================================================== */

.features-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
}

@media (min-width: 768px) {
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (min-width: 1024px) {
    .features-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

.feature-card {
    padding: var(--spacing-xl);
    background-color: var(--color-bg-secondary);
    border-radius: var(--radius-lg);
    border: 1px solid var(--color-border);
    transition: all var(--transition-base);
}

.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--color-primary);
}

.feature-icon {
    width: 48px;
    height: 48px;
    margin-bottom: var(--spacing-md);
    color: var(--color-primary);
}

.feature-icon .icon {
    width: 100%;
    height: 100%;
}

.feature-title {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-md);
}

.feature-description {
    color: var(--color-text-tertiary);
    margin-bottom: var(--spacing-md);
}

.feature-link {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    color: var(--color-primary);
    font-weight: 500;
}

.feature-link .icon {
    width: 16px;
    height: 16px;
}

/* ===================================================================
   TRUST INDICATORS
   =================================================================== */

.trust-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-md);
    max-width: 900px;
    margin: 0 auto;
}

@media (min-width: 768px) {
    .trust-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

.trust-item {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    background-color: var(--color-bg-secondary);
    border-radius: var(--radius-md);
    border-left: 3px solid var(--color-success);
}

.trust-icon {
    width: 24px;
    height: 24px;
    color: var(--color-success);
    flex-shrink: 0;
    margin-top: 2px;
}

.trust-text {
    color: var(--color-text-secondary);
    line-height: 1.6;
}

/* ===================================================================
   GUIDE CARDS
   =================================================================== */

.guides-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
}

@media (min-width: 768px) {
    .guides-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (min-width: 1024px) {
    .guides-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

.guide-card {
    padding: var(--spacing-xl);
    background-color: var(--color-bg-secondary);
    border-radius: var(--radius-lg);
    border: 1px solid var(--color-border);
    transition: all var(--transition-base);
    display: flex;
    flex-direction: column;
}

.guide-card:hover {
    transform: translateY(-2px);
    border-color: var(--color-primary);
    box-shadow: var(--shadow-md);
}

.guide-icon {
    width: 40px;
    height: 40px;
    margin-bottom: var(--spacing-md);
    color: var(--color-primary);
}

.guide-icon svg {
    width: 100%;
    height: 100%;
}

.guide-title {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-md);
}

.guide-description {
    color: var(--color-text-tertiary);
    flex-grow: 1;
    margin-bottom: var(--spacing-md);
}

.guide-meta {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
    font-size: 0.875rem;
}

.guide-difficulty {
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.difficulty-beginner {
    background-color: rgba(16, 185, 129, 0.2);
    color: var(--color-success);
}

.difficulty-intermediate {
    background-color: rgba(245, 158, 11, 0.2);
    color: var(--color-warning);
}

.difficulty-advanced {
    background-color: rgba(239, 68, 68, 0.2);
    color: var(--color-danger);
}

.guide-time {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    color: var(--color-text-muted);
}

.guide-time .icon {
    width: 14px;
    height: 14px;
}

.guide-link {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    color: var(--color-primary);
    font-weight: 500;
}

.guide-link .icon {
    width: 16px;
    height: 16px;
    transition: transform var(--transition-fast);
}

.guide-link:hover .icon {
    transform: translateX(2px);
}

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

.faq-list {
    max-width: 900px;
    margin: 0 auto;
}

.faq-item {
    margin-bottom: var(--spacing-md);
    background-color: var(--color-bg-secondary);
    border-radius: var(--radius-md);
    border: 1px solid var(--color-border);
    overflow: hidden;
}

.faq-question {
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-lg);
    background: none;
    border: none;
    text-align: left;
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--color-text-primary);
    cursor: pointer;
    transition: background-color var(--transition-fast);
}

.faq-question:hover {
    background-color: rgba(59, 130, 246, 0.05);
}

.faq-icon {
    width: 24px;
    height: 24px;
    color: var(--color-primary);
    transition: transform var(--transition-base);
    flex-shrink: 0;
}

.faq-item.active .faq-icon {
    transform: rotate(180deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-slow);
}

.faq-item.active .faq-answer {
    max-height: 1000px;
}

.faq-answer p {
    padding: 0 var(--spacing-lg) var(--spacing-lg);
    color: var(--color-text-tertiary);
    line-height: 1.7;
}

/* ===================================================================
   ALERTS
   =================================================================== */

.alert {
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--radius-md);
    border-left: 4px solid;
    margin-bottom: var(--spacing-lg);
}

.alert-info {
    background-color: rgba(59, 130, 246, 0.1);
    border-color: var(--color-info);
    color: var(--color-text-secondary);
}

.alert-success {
    background-color: rgba(16, 185, 129, 0.1);
    border-color: var(--color-success);
    color: var(--color-text-secondary);
}

.alert-warning {
    background-color: rgba(245, 158, 11, 0.1);
    border-color: var(--color-warning);
    color: var(--color-text-secondary);
}

.alert-danger {
    background-color: rgba(239, 68, 68, 0.1);
    border-color: var(--color-danger);
    color: var(--color-text-secondary);
}

.alert-large {
    padding: var(--spacing-xl);
}

.alert-icon {
    display: inline-block;
    width: 32px;
    height: 32px;
    margin-right: var(--spacing-md);
    vertical-align: top;
}

.alert-content {
    display: inline-block;
    width: calc(100% - 48px);
}

.alert-title {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-md);
    color: var(--color-text-primary);
}

.alert-list {
    margin-bottom: 0;
}

/* ===================================================================
   PAGE HEADERS
   =================================================================== */

.page-header {
    padding: var(--spacing-3xl) 0 var(--spacing-2xl);
    text-align: center;
    background: linear-gradient(180deg, var(--color-bg-secondary) 0%, var(--color-bg-primary) 100%);
    border-bottom: 1px solid var(--color-border);
}

.page-title {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-md);
}

.page-description {
    font-size: 1.125rem;
    color: var(--color-text-tertiary);
    max-width: 800px;
    margin: 0 auto;
}

.page-meta {
    margin-top: var(--spacing-md);
    font-size: 0.875rem;
    color: var(--color-text-muted);
}

/* ===================================================================
   BREADCRUMBS
   =================================================================== */

.breadcrumbs {
    padding: var(--spacing-md) 0;
    background-color: var(--color-bg-secondary);
    border-bottom: 1px solid var(--color-border);
}

.breadcrumb-list {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
    list-style: none;
    margin: 0;
    padding: 0;
    font-size: 0.875rem;
}

.breadcrumb-item {
    display: flex;
    align-items: center;
    color: var(--color-text-tertiary);
}

.breadcrumb-item:not(:last-child)::after {
    content: '/';
    margin-left: var(--spacing-sm);
    color: var(--color-border-light);
}

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

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

/* ===================================================================
   GUIDE PAGES
   =================================================================== */

.guide-header {
    padding: var(--spacing-2xl) 0;
    background-color: var(--color-bg-secondary);
    border-bottom: 1px solid var(--color-border);
}

.guide-title {
    font-size: 2.25rem;
    margin-bottom: var(--spacing-md);
}

.guide-meta-bar {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-lg);
    font-size: 0.875rem;
    color: var(--color-text-tertiary);
}

.guide-meta-bar > * {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.guide-content {
    padding: var(--spacing-3xl) 0;
}

.guide-layout {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-3xl);
}

@media (min-width: 1024px) {
    .guide-layout {
        grid-template-columns: 280px 1fr;
    }
}

/* Table of Contents */
.guide-sidebar {
    display: none;
}

@media (min-width: 1024px) {
    .guide-sidebar {
        display: block;
    }
}

.toc-sticky {
    position: sticky;
    top: calc(var(--header-height) + var(--spacing-lg));
}

.toc-title {
    font-size: 1rem;
    margin-bottom: var(--spacing-md);
    color: var(--color-text-primary);
}

.toc-nav {
    border-left: 2px solid var(--color-border);
}

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

.toc-link {
    display: block;
    padding: var(--spacing-sm) var(--spacing-md);
    color: var(--color-text-tertiary);
    font-size: 0.875rem;
    border-left: 2px solid transparent;
    margin-left: -2px;
    transition: all var(--transition-fast);
}

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

/* Guide Article */
.guide-article {
    max-width: 800px;
}

.guide-section {
    margin-bottom: var(--spacing-3xl);
}

.guide-section h2 {
    font-size: 1.875rem;
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-md);
    border-bottom: 2px solid var(--color-border);
}

.guide-section h3 {
    font-size: 1.5rem;
    margin-top: var(--spacing-xl);
    margin-bottom: var(--spacing-md);
}

.guide-section h4 {
    font-size: 1.25rem;
    margin-top: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
}

/* ===================================================================
   ERROR PAGE
   =================================================================== */

.error-page {
    min-height: 60vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-4xl) 0;
}

.error-content {
    text-align: center;
    max-width: 600px;
}

.error-code {
    font-size: 6rem;
    font-weight: 700;
    color: var(--color-primary);
    line-height: 1;
    margin-bottom: var(--spacing-md);
}

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

.error-description {
    font-size: 1.125rem;
    color: var(--color-text-tertiary);
    margin-bottom: var(--spacing-2xl);
}

.error-actions {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    flex-wrap: wrap;
}

/* ===================================================================
   RESPONSIVE UTILITIES
   =================================================================== */

@media (max-width: 767px) {
    h1 { font-size: 2rem; }
    h2 { font-size: 1.75rem; }
    h3 { font-size: 1.5rem; }

    .hero-title {
        font-size: 2rem;
    }

    .section-title {
        font-size: 1.875rem;
    }
}

@media (min-width: 1536px) {
    .container {
        max-width: var(--container-2xl);
    }
}

/* ===================================================================
   PRINT STYLES
   =================================================================== */

@media print {
    .site-header,
    .site-footer,
    .guide-sidebar,
    .back-to-top,
    .mobile-menu-toggle {
        display: none !important;
    }

    body {
        background-color: white;
        color: black;
    }

    a {
        color: black;
        text-decoration: underline;
    }
}

/* ===================================================================
   ENHANCED HEADER & NAVIGATION
   =================================================================== */

.navbar {
    width: 100%;
}

.navbar-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: var(--header-height);
    padding: 0 var(--spacing-md);
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    color: var(--color-text-primary);
    font-size: 1.5rem;
    font-weight: 700;
    transition: all var(--transition-fast);
    text-decoration: none;
}

.logo:hover {
    color: var(--color-primary-light);
    transform: translateY(-2px);
}

.logo-icon {
    width: 32px !important;
    height: 32px !important;
    min-width: 32px;
    min-height: 32px;
    max-width: 32px;
    max-height: 32px;
    color: var(--color-primary);
    display: inline-block;
    flex-shrink: 0;
}

.logo-text {
    font-weight: 700;
    letter-spacing: -0.5px;
}

.logo-accent {
    color: var(--color-primary);
    font-weight: 800;
}

/* Mobile Menu Toggle */
.mobile-menu-toggle {
    display: flex;
    flex-direction: column;
    gap: 5px;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 8px;
    z-index: 1001;
}

.mobile-menu-toggle span {
    width: 25px;
    height: 2px;
    background-color: var(--color-text-primary);
    transition: all var(--transition-base);
    border-radius: 2px;
}

.mobile-menu-toggle:hover span {
    background-color: var(--color-primary);
}

/* Navigation Links */
.nav-links {
    display: none;
    flex-direction: column;
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    background-color: rgba(15, 23, 42, 0.98);
    backdrop-filter: blur(20px);
    padding: var(--spacing-xl);
    border-top: 1px solid var(--color-border);
    box-shadow: var(--shadow-xl);
    max-height: calc(100vh - var(--header-height));
    overflow-y: auto;
}

.nav-links.active {
    display: flex;
}

@media (min-width: 768px) {
    .mobile-menu-toggle {
        display: none;
    }

    .nav-links {
        display: flex;
        flex-direction: row;
        position: static;
        background: transparent;
        backdrop-filter: none;
        padding: 0;
        border: none;
        box-shadow: none;
        gap: var(--spacing-sm);
        align-items: center;
    }
}

.nav-link {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md);
    color: var(--color-text-secondary);
    font-weight: 500;
    font-size: 1rem;
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
    position: relative;
}

@media (min-width: 768px) {
    .nav-link {
        padding: var(--spacing-sm) var(--spacing-md);
    }
}

.nav-link:hover {
    color: var(--color-primary-light);
    background-color: rgba(59, 130, 246, 0.1);
}

.nav-link.active {
    color: var(--color-primary);
    background-color: rgba(59, 130, 246, 0.15);
}

.nav-link.active::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 3px;
    height: 60%;
    background: var(--color-primary);
    border-radius: 2px;
}

@media (min-width: 768px) {
    .nav-link.active::before {
        display: none;
    }

    .nav-link.active::after {
        content: '';
        position: absolute;
        bottom: -2px;
        left: 50%;
        transform: translateX(-50%);
        width: 60%;
        height: 2px;
        background: var(--color-primary);
        border-radius: 2px;
    }
}

.nav-icon {
    width: 20px !important;
    height: 20px !important;
    min-width: 20px;
    min-height: 20px;
    max-width: 20px;
    max-height: 20px;
    flex-shrink: 0;
    display: inline-block;
    vertical-align: middle;
}

@media (min-width: 768px) {
    .nav-icon {
        width: 18px !important;
        height: 18px !important;
        min-width: 18px;
        min-height: 18px;
        max-width: 18px;
        max-height: 18px;
    }
}

.nav-cta {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-xl);
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
    color: white;
    font-weight: 600;
    border-radius: var(--radius-lg);
    transition: all var(--transition-base);
    margin-top: var(--spacing-lg);
    box-shadow: 0 4px 15px rgba(59, 130, 246, 0.3);
}

@media (min-width: 768px) {
    .nav-cta {
        margin-top: 0;
        padding: var(--spacing-sm) var(--spacing-lg);
        margin-left: var(--spacing-md);
    }
}

.nav-cta:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(59, 130, 246, 0.4);
    color: white;
}

/* ===================================================================
   ENHANCED FOOTER
   =================================================================== */

.footer-content {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-2xl);
    margin-bottom: var(--spacing-3xl);
}

@media (min-width: 640px) {
    .footer-content {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (min-width: 1024px) {
    .footer-content {
        grid-template-columns: 2fr 1fr 1fr 1fr;
    }
}

.footer-section {
    display: flex;
    flex-direction: column;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-lg);
    font-size: 1.5rem;
    font-weight: 700;
}

.footer-logo-icon {
    width: 40px;
    height: 40px;
    color: var(--color-primary);
}

.footer-logo-text {
    font-weight: 700;
    color: var(--color-text-primary);
}

.footer-logo-accent {
    color: var(--color-primary);
}

.footer-description {
    color: var(--color-text-tertiary);
    line-height: 1.7;
    font-size: 0.95rem;
}

.footer-title {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-lg);
}

.footer-links {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.footer-links a {
    color: var(--color-text-secondary);
    transition: all var(--transition-fast);
    display: inline-flex;
    align-items: center;
    position: relative;
    padding-left: 0;
}

.footer-links a::before {
    content: '→';
    position: absolute;
    left: -20px;
    opacity: 0;
    transition: all var(--transition-fast);
    color: var(--color-primary);
}

.footer-links a:hover {
    color: var(--color-primary);
    padding-left: 20px;
}

.footer-links a:hover::before {
    opacity: 1;
}

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

.footer-bottom-content {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
    align-items: center;
    text-align: center;
}

@media (min-width: 768px) {
    .footer-bottom-content {
        flex-direction: row;
        justify-content: space-between;
        text-align: left;
    }
}

.footer-copyright {
    color: var(--color-text-tertiary);
    font-size: 0.9rem;
}

.footer-legal {
    display: flex;
    gap: var(--spacing-lg);
    flex-wrap: wrap;
}

.footer-disclaimer {
    color: var(--color-warning);
    font-size: 0.875rem;
    font-weight: 500;
}