/* ==========================================================================
   BlockLearn Academy - Main Stylesheet
   Version: 1.0.0
   ========================================================================== */

/* ==========================================================================
   CSS Custom Properties
   ========================================================================== */
:root {
	/* Colors */
	--color-bg: #ffffff;
	--color-bg-alt: #f8f9fa;
	--color-bg-elevated: #ffffff;
	--color-text: #1a1d23;
	--color-text-secondary: #5a6070;
	--color-text-muted: #8891a5;
	--color-border: #e2e5ea;
	--color-border-light: #eef0f4;
	--color-accent: #0d9488;
	--color-accent-hover: #0b8278;
	--color-accent-light: #f0fdfa;
	--color-accent-text: #ffffff;
	--color-card-bg: #ffffff;
	--color-card-border: #eef0f4;
	--color-hero-bg: #f8f9fa;
	--color-footer-bg: #1a1d23;
	--color-footer-text: #b0b8c8;
	--color-footer-heading: #ffffff;
	--color-code-bg: #f1f3f7;
	--color-code-text: #1a1d23;

	/* Typography */
	--font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
	--font-heading: 'Source Serif 4', Georgia, 'Times New Roman', serif;
	--font-mono: 'SF Mono', 'Fira Code', 'Fira Mono', 'Roboto Mono', monospace;

	/* Spacing */
	--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;

	/* Layout */
	--container-max: 1200px;
	--container-narrow: 760px;
	--header-height: 72px;
	--border-radius: 6px;
	--border-radius-lg: 10px;

	/* Shadows */
	--shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
	--shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
	--shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.1);

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

/* ==========================================================================
   Dark Mode
   ========================================================================== */
.dark-mode {
	--color-bg: #111318;
	--color-bg-alt: #181b22;
	--color-bg-elevated: #1e2128;
	--color-text: #e4e6eb;
	--color-text-secondary: #a0a7b8;
	--color-text-muted: #6b7389;
	--color-border: #2a2e37;
	--color-border-light: #22262e;
	--color-card-bg: #1e2128;
	--color-card-border: #2a2e37;
	--color-hero-bg: #181b22;
	--color-code-bg: #1e2128;
	--color-code-text: #e4e6eb;
	--shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.2);
	--shadow-md: 0 4px 12px rgba(0, 0, 0, 0.3);
	--shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.4);
}

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

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

body {
	font-family: var(--font-body);
	font-size: 1rem;
	line-height: 1.7;
	color: var(--color-text);
	background-color: var(--color-bg);
	-webkit-font-smoothing: antialiased;
	-moz-osx-font-smoothing: grayscale;
}

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

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

a:hover {
	color: var(--color-accent-hover);
}

ul,
ol {
	list-style: none;
}

h1, h2, h3, h4, h5, h6 {
	font-family: var(--font-heading);
	font-weight: 700;
	line-height: 1.3;
	color: var(--color-text);
}

h1 { font-size: 2.25rem; }
h2 { font-size: 1.75rem; }
h3 { font-size: 1.375rem; }
h4 { font-size: 1.125rem; }

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

/* ==========================================================================
   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 !important;
}

.screen-reader-text:focus {
	background-color: #f1f1f1;
	border-radius: 3px;
	box-shadow: 0 0 2px 2px rgba(0, 0, 0, 0.6);
	clip: auto !important;
	clip-path: none;
	color: #21759b;
	display: block;
	font-size: 0.875rem;
	font-weight: 700;
	height: auto;
	left: 5px;
	line-height: normal;
	padding: 15px 23px 14px;
	text-decoration: none;
	top: 5px;
	width: auto;
	z-index: 100000;
}

.skip-link:focus {
	z-index: 999999;
}

/* ==========================================================================
   Layout
   ========================================================================== */
.container {
	max-width: var(--container-max);
	margin-left: auto;
	margin-right: auto;
	padding-left: var(--spacing-xl);
	padding-right: var(--spacing-xl);
}

.site-content {
	min-height: 60vh;
}

.content-area-with-sidebar {
	display: grid;
	grid-template-columns: 1fr;
	gap: var(--spacing-3xl);
}

@media (min-width: 992px) {
	.content-area-with-sidebar {
		grid-template-columns: 1fr 300px;
	}
}

/* ==========================================================================
   Header
   ========================================================================== */
.site-header {
	position: sticky;
	top: 0;
	z-index: 1000;
	background-color: var(--color-bg);
	border-bottom: 1px solid var(--color-border);
	height: var(--header-height);
	display: flex;
	align-items: center;
}

.header-inner {
	display: flex;
	align-items: center;
	justify-content: space-between;
	gap: var(--spacing-xl);
}

.site-branding {
	flex-shrink: 0;
}

.site-title-link {
	display: flex;
	flex-direction: column;
	text-decoration: none;
}

.site-title {
	font-family: var(--font-heading);
	font-size: 1.375rem;
	font-weight: 700;
	color: var(--color-text);
	line-height: 1.2;
}

.site-description {
	font-size: 0.75rem;
	color: var(--color-text-muted);
	line-height: 1.3;
}

.site-logo img {
	max-height: 44px;
	width: auto;
}

/* ==========================================================================
   Navigation
   ========================================================================== */
.main-navigation {
	display: none;
}

@media (min-width: 992px) {
	.main-navigation {
		display: flex;
		align-items: center;
	}
}

.nav-menu {
	display: flex;
	align-items: center;
	gap: var(--spacing-xs);
	list-style: none;
	margin: 0;
	padding: 0;
}

.nav-menu li {
	position: relative;
}

.nav-menu a {
	display: block;
	padding: var(--spacing-sm) var(--spacing-md);
	font-size: 0.9375rem;
	font-weight: 500;
	color: var(--color-text-secondary);
	text-decoration: none;
	border-radius: var(--border-radius);
	transition: color var(--transition-fast), background-color var(--transition-fast);
}

.nav-menu a:hover,
.nav-menu .current-menu-item > a,
.nav-menu .current_page_item > a {
	color: var(--color-accent);
	background-color: var(--color-accent-light);
}

/* Dropdown menus */
.nav-menu .sub-menu {
	display: none;
	position: absolute;
	top: 100%;
	left: 0;
	min-width: 220px;
	background-color: var(--color-bg-elevated);
	border: 1px solid var(--color-border);
	border-radius: var(--border-radius);
	box-shadow: var(--shadow-md);
	padding: var(--spacing-sm) 0;
	z-index: 100;
}

.nav-menu .sub-menu a {
	padding: var(--spacing-sm) var(--spacing-lg);
	font-size: 0.875rem;
	border-radius: 0;
}

.nav-menu li:hover > .sub-menu {
	display: block;
}

/* ==========================================================================
   Header Actions
   ========================================================================== */
.header-actions {
	display: flex;
	align-items: center;
	gap: var(--spacing-sm);
}

.header-actions button {
	display: flex;
	align-items: center;
	justify-content: center;
	width: 40px;
	height: 40px;
	background: none;
	border: 1px solid var(--color-border);
	border-radius: var(--border-radius);
	color: var(--color-text-secondary);
	cursor: pointer;
	transition: color var(--transition-fast), border-color var(--transition-fast);
}

.header-actions button:hover {
	color: var(--color-accent);
	border-color: var(--color-accent);
}

/* Dark Mode Toggle */
.dark-mode-toggle .icon-moon {
	display: none;
}

.dark-mode .dark-mode-toggle .icon-sun {
	display: none;
}

.dark-mode .dark-mode-toggle .icon-moon {
	display: block;
}

/* Mobile Menu Toggle */
.mobile-menu-toggle {
	display: flex !important;
	flex-direction: column;
	gap: 5px;
	padding: 10px !important;
}

.hamburger-line {
	display: block;
	width: 20px;
	height: 2px;
	background-color: currentColor;
	border-radius: 2px;
	transition: transform var(--transition-base), opacity var(--transition-base);
}

.mobile-menu-toggle[aria-expanded="true"] .hamburger-line:nth-child(1) {
	transform: translateY(7px) rotate(45deg);
}

.mobile-menu-toggle[aria-expanded="true"] .hamburger-line:nth-child(2) {
	opacity: 0;
}

.mobile-menu-toggle[aria-expanded="true"] .hamburger-line:nth-child(3) {
	transform: translateY(-7px) rotate(-45deg);
}

@media (min-width: 992px) {
	.mobile-menu-toggle {
		display: none !important;
	}
}

/* Mobile Navigation */
@media (max-width: 991px) {
	.main-navigation {
		position: fixed;
		top: var(--header-height);
		left: 0;
		right: 0;
		bottom: 0;
		background-color: var(--color-bg);
		padding: var(--spacing-xl);
		overflow-y: auto;
		transform: translateX(100%);
		transition: transform var(--transition-base);
		z-index: 999;
	}

	.main-navigation.is-active {
		transform: translateX(0);
	}

	.nav-menu {
		flex-direction: column;
		align-items: stretch;
		gap: 0;
	}

	.nav-menu a {
		padding: var(--spacing-md);
		font-size: 1rem;
		border-bottom: 1px solid var(--color-border-light);
	}

	.nav-menu .sub-menu {
		position: static;
		box-shadow: none;
		border: none;
		padding-left: var(--spacing-lg);
		display: none;
	}

	.nav-menu .menu-item-has-children.is-active > .sub-menu {
		display: block;
	}
}

/* ==========================================================================
   Search Overlay
   ========================================================================== */
.search-overlay {
	position: fixed;
	top: 0;
	left: 0;
	right: 0;
	bottom: 0;
	background-color: rgba(0, 0, 0, 0.6);
	backdrop-filter: blur(4px);
	display: flex;
	align-items: flex-start;
	justify-content: center;
	padding-top: 120px;
	z-index: 2000;
	opacity: 0;
	visibility: hidden;
	transition: opacity var(--transition-base), visibility var(--transition-base);
}

.search-overlay.is-active {
	opacity: 1;
	visibility: visible;
}

.search-overlay-inner {
	background-color: var(--color-bg);
	border-radius: var(--border-radius-lg);
	padding: var(--spacing-xl);
	width: 90%;
	max-width: 600px;
	box-shadow: var(--shadow-lg);
	position: relative;
	transform: translateY(-20px);
	transition: transform var(--transition-base);
}

.search-overlay.is-active .search-overlay-inner {
	transform: translateY(0);
}

.search-close {
	position: absolute;
	top: var(--spacing-md);
	right: var(--spacing-md);
	background: none;
	border: none;
	font-size: 1.5rem;
	color: var(--color-text-muted);
	cursor: pointer;
	padding: var(--spacing-xs);
	line-height: 1;
}

.search-close:hover {
	color: var(--color-text);
}

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

.search-field {
	flex: 1;
	padding: var(--spacing-md) var(--spacing-lg);
	font-size: 1rem;
	font-family: var(--font-body);
	border: 1px solid var(--color-border);
	border-radius: var(--border-radius);
	background-color: var(--color-bg);
	color: var(--color-text);
	outline: none;
	transition: border-color var(--transition-fast);
}

.search-field:focus {
	border-color: var(--color-accent);
}

.search-submit {
	padding: var(--spacing-md) var(--spacing-xl);
	font-size: 0.9375rem;
	font-weight: 600;
	font-family: var(--font-body);
	background-color: var(--color-accent);
	color: var(--color-accent-text);
	border: none;
	border-radius: var(--border-radius);
	cursor: pointer;
	transition: background-color var(--transition-fast);
}

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

/* ==========================================================================
   Buttons
   ========================================================================== */
.btn {
	display: inline-flex;
	align-items: center;
	justify-content: center;
	gap: var(--spacing-sm);
	padding: 0.75rem 1.5rem;
	font-size: 0.9375rem;
	font-weight: 600;
	font-family: var(--font-body);
	text-decoration: none;
	border-radius: var(--border-radius);
	border: 2px solid transparent;
	cursor: pointer;
	transition: all var(--transition-fast);
	line-height: 1.4;
}

.btn-primary {
	background-color: var(--color-accent);
	color: var(--color-accent-text);
	border-color: var(--color-accent);
}

.btn-primary:hover {
	background-color: var(--color-accent-hover);
	border-color: var(--color-accent-hover);
	color: var(--color-accent-text);
}

.btn-outline {
	background-color: transparent;
	color: var(--color-accent);
	border-color: var(--color-accent);
}

.btn-outline:hover {
	background-color: var(--color-accent);
	color: var(--color-accent-text);
}

.btn-lg {
	padding: 1rem 2rem;
	font-size: 1rem;
}

/* ==========================================================================
   Hero Section
   ========================================================================== */
.hero-section {
	background-color: var(--color-hero-bg);
	padding: var(--spacing-4xl) 0;
	text-align: center;
	border-bottom: 1px solid var(--color-border);
}

.hero-content {
	max-width: 720px;
	margin: 0 auto;
}

.hero-headline {
	font-size: 2.75rem;
	font-weight: 700;
	margin-bottom: var(--spacing-lg);
	line-height: 1.15;
	letter-spacing: -0.02em;
}

.hero-subtext {
	font-size: 1.1875rem;
	color: var(--color-text-secondary);
	line-height: 1.7;
	margin-bottom: var(--spacing-2xl);
	max-width: 600px;
	margin-left: auto;
	margin-right: auto;
}

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

@media (max-width: 480px) {
	.hero-headline {
		font-size: 2rem;
	}

	.hero-subtext {
		font-size: 1rem;
	}

	.hero-ctas {
		flex-direction: column;
		align-items: center;
	}

	.hero-ctas .btn {
		width: 100%;
		max-width: 280px;
	}
}

/* ==========================================================================
   Sections
   ========================================================================== */
.section {
	padding: var(--spacing-4xl) 0;
}

.section + .section {
	border-top: 1px solid var(--color-border-light);
}

.section-header {
	text-align: center;
	margin-bottom: var(--spacing-3xl);
	max-width: 640px;
	margin-left: auto;
	margin-right: auto;
}

.section-title {
	margin-bottom: var(--spacing-md);
}

.section-subtitle {
	font-size: 1.0625rem;
	color: var(--color-text-secondary);
	line-height: 1.6;
}

.section-footer {
	text-align: center;
	margin-top: var(--spacing-2xl);
}

/* ==========================================================================
   Cards Grid
   ========================================================================== */
.cards-grid {
	display: grid;
	gap: var(--spacing-xl);
}

.cards-grid-3 {
	grid-template-columns: 1fr;
}

@media (min-width: 640px) {
	.cards-grid-3 {
		grid-template-columns: repeat(2, 1fr);
	}
}

@media (min-width: 992px) {
	.cards-grid-3 {
		grid-template-columns: repeat(3, 1fr);
	}
}

/* ==========================================================================
   Card Component
   ========================================================================== */
.card {
	background-color: var(--color-card-bg);
	border: 1px solid var(--color-card-border);
	border-radius: var(--border-radius-lg);
	overflow: hidden;
	transition: box-shadow var(--transition-base), transform var(--transition-base);
}

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

.card-image {
	display: block;
	overflow: hidden;
	aspect-ratio: 16 / 10;
}

.card-image img {
	width: 100%;
	height: 100%;
	object-fit: cover;
	transition: transform var(--transition-slow);
}

.card:hover .card-image img {
	transform: scale(1.03);
}

.card-body {
	padding: var(--spacing-lg);
}

.card-meta {
	display: flex;
	align-items: center;
	gap: var(--spacing-sm);
	margin-bottom: var(--spacing-sm);
	font-size: 0.8125rem;
	color: var(--color-text-muted);
}

.card-topic {
	background-color: var(--color-accent-light);
	color: var(--color-accent);
	padding: 2px 10px;
	border-radius: 20px;
	font-weight: 600;
	font-size: 0.75rem;
	text-transform: uppercase;
	letter-spacing: 0.03em;
}

.dark-mode .card-topic {
	background-color: rgba(13, 148, 136, 0.15);
}

.card-title {
	font-size: 1.1875rem;
	margin-bottom: var(--spacing-sm);
	line-height: 1.35;
}

.card-title a {
	color: var(--color-text);
	text-decoration: none;
}

.card-title a:hover {
	color: var(--color-accent);
}

.card-excerpt {
	font-size: 0.9375rem;
	color: var(--color-text-secondary);
	line-height: 1.6;
	margin-bottom: var(--spacing-md);
	display: -webkit-box;
	-webkit-line-clamp: 3;
	-webkit-box-orient: vertical;
	overflow: hidden;
}

.card-link {
	display: inline-flex;
	align-items: center;
	gap: var(--spacing-xs);
	font-size: 0.9375rem;
	font-weight: 600;
	color: var(--color-accent);
}

.card-link:hover {
	gap: var(--spacing-sm);
}

.card-placeholder .card-body {
	padding: var(--spacing-xl);
}

/* ==========================================================================
   Categories Grid
   ========================================================================== */
.categories-grid {
	display: grid;
	gap: var(--spacing-lg);
	grid-template-columns: 1fr;
}

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

@media (min-width: 992px) {
	.categories-grid {
		grid-template-columns: repeat(3, 1fr);
	}
}

.category-card {
	display: flex;
	flex-direction: column;
	padding: var(--spacing-xl);
	background-color: var(--color-card-bg);
	border: 1px solid var(--color-card-border);
	border-radius: var(--border-radius-lg);
	text-decoration: none;
	transition: border-color var(--transition-base), box-shadow var(--transition-base), transform var(--transition-base);
}

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

.category-icon {
	width: 56px;
	height: 56px;
	display: flex;
	align-items: center;
	justify-content: center;
	border-radius: var(--border-radius);
	background-color: var(--color-accent-light);
	color: var(--color-accent);
	font-size: 1.5rem;
	font-weight: 700;
	margin-bottom: var(--spacing-md);
	flex-shrink: 0;
}

.dark-mode .category-icon {
	background-color: rgba(13, 148, 136, 0.15);
}

.category-title {
	font-size: 1.125rem;
	margin-bottom: var(--spacing-sm);
	color: var(--color-text);
}

.category-desc {
	font-size: 0.875rem;
	color: var(--color-text-secondary);
	line-height: 1.6;
}

/* ==========================================================================
   Features Grid (Why Learn Blockchain)
   ========================================================================== */
.features-grid {
	display: grid;
	gap: var(--spacing-xl);
	grid-template-columns: 1fr;
}

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

@media (min-width: 992px) {
	.features-grid {
		grid-template-columns: repeat(4, 1fr);
	}
}

.feature-item {
	text-align: center;
	padding: var(--spacing-xl);
}

.feature-icon {
	display: inline-flex;
	align-items: center;
	justify-content: center;
	width: 64px;
	height: 64px;
	border-radius: 50%;
	background-color: var(--color-accent-light);
	color: var(--color-accent);
	margin-bottom: var(--spacing-lg);
}

.dark-mode .feature-icon {
	background-color: rgba(13, 148, 136, 0.15);
}

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

.feature-desc {
	font-size: 0.875rem;
	color: var(--color-text-secondary);
	line-height: 1.6;
}

/* ==========================================================================
   Callout Section (Smart Contract Security)
   ========================================================================== */
.security-callout {
	background-color: var(--color-bg-alt);
}

.callout-grid {
	display: grid;
	gap: var(--spacing-2xl);
	align-items: center;
}

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

.callout-label {
	display: inline-block;
	font-size: 0.75rem;
	font-weight: 700;
	text-transform: uppercase;
	letter-spacing: 0.08em;
	color: var(--color-accent);
	margin-bottom: var(--spacing-md);
	background-color: var(--color-accent-light);
	padding: 4px 12px;
	border-radius: 20px;
}

.dark-mode .callout-label {
	background-color: rgba(13, 148, 136, 0.15);
}

.callout-title {
	margin-bottom: var(--spacing-lg);
}

.callout-text {
	font-size: 1.0625rem;
	color: var(--color-text-secondary);
	line-height: 1.7;
	margin-bottom: var(--spacing-xl);
}

.callout-list {
	display: flex;
	flex-direction: column;
	gap: var(--spacing-md);
}

.callout-list li {
	display: flex;
	flex-direction: column;
	padding: var(--spacing-md) var(--spacing-lg);
	background-color: var(--color-bg);
	border: 1px solid var(--color-border);
	border-radius: var(--border-radius);
}

.callout-list strong {
	font-size: 0.9375rem;
	color: var(--color-text);
	margin-bottom: 2px;
}

.callout-list span {
	font-size: 0.8125rem;
	color: var(--color-text-muted);
}

/* ==========================================================================
   Newsletter Section
   ========================================================================== */
.newsletter-section {
	background-color: var(--color-bg-alt);
	border-top: 1px solid var(--color-border-light);
}

.newsletter-inner {
	display: flex;
	flex-direction: column;
	gap: var(--spacing-xl);
	align-items: center;
	text-align: center;
	max-width: 640px;
	margin: 0 auto;
}

.newsletter-title {
	margin-bottom: var(--spacing-sm);
}

.newsletter-text {
	font-size: 1.0625rem;
	color: var(--color-text-secondary);
	line-height: 1.6;
	margin-bottom: 0;
}

.newsletter-form-wrapper {
	width: 100%;
	max-width: 480px;
}

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

.newsletter-input {
	flex: 1;
	padding: 0.875rem 1.25rem;
	font-size: 0.9375rem;
	font-family: var(--font-body);
	border: 1px solid var(--color-border);
	border-radius: var(--border-radius);
	background-color: var(--color-bg);
	color: var(--color-text);
	outline: none;
	transition: border-color var(--transition-fast);
}

.newsletter-input:focus {
	border-color: var(--color-accent);
}

.newsletter-submit {
	flex-shrink: 0;
}

.newsletter-notice {
	font-size: 0.8125rem;
	color: var(--color-text-muted);
	margin-top: var(--spacing-sm);
	margin-bottom: 0;
}

.newsletter-response {
	margin-top: var(--spacing-md);
	font-size: 0.9375rem;
}

.newsletter-response.success {
	color: #16a34a;
}

.newsletter-response.error {
	color: #dc2626;
}

@media (max-width: 480px) {
	.newsletter-form-row {
		flex-direction: column;
	}
}

/* ==========================================================================
   Footer
   ========================================================================== */
.site-footer {
	background-color: var(--color-footer-bg);
	color: var(--color-footer-text);
	padding: var(--spacing-3xl) 0 var(--spacing-xl);
}

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

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

@media (min-width: 992px) {
	.footer-widgets {
		grid-template-columns: repeat(3, 1fr);
	}
}

.footer-widget-area .widget-title {
	color: var(--color-footer-heading);
	font-size: 1rem;
	margin-bottom: var(--spacing-md);
}

.footer-widget-area p {
	font-size: 0.875rem;
	line-height: 1.6;
	margin-bottom: var(--spacing-md);
}

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

.footer-widget-area ul li {
	margin-bottom: var(--spacing-sm);
}

.footer-widget-area ul a {
	color: var(--color-footer-text);
	font-size: 0.875rem;
	text-decoration: none;
	transition: color var(--transition-fast);
}

.footer-widget-area ul a:hover {
	color: var(--color-footer-heading);
}

.footer-navigation {
	margin-top: var(--spacing-xl);
	padding-top: var(--spacing-xl);
	border-top: 1px solid rgba(255, 255, 255, 0.1);
}

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

.footer-nav a {
	color: var(--color-footer-text);
	font-size: 0.875rem;
	text-decoration: none;
}

.footer-nav a:hover {
	color: var(--color-footer-heading);
}

.site-info {
	margin-top: var(--spacing-xl);
	padding-top: var(--spacing-xl);
	border-top: 1px solid rgba(255, 255, 255, 0.1);
	text-align: center;
}

.copyright {
	font-size: 0.8125rem;
	color: var(--color-text-muted);
	margin: 0;
}

/* ==========================================================================
   Breadcrumbs
   ========================================================================== */
.breadcrumbs {
	padding: var(--spacing-md) 0;
	border-bottom: 1px solid var(--color-border-light);
	background-color: var(--color-bg);
}

.breadcrumbs .container {
	font-size: 0.8125rem;
	color: var(--color-text-muted);
}

.breadcrumbs a {
	color: var(--color-text-muted);
	text-decoration: none;
}

.breadcrumbs a:hover {
	color: var(--color-accent);
}

.breadcrumbs .separator {
	margin: 0 var(--spacing-sm);
	color: var(--color-border);
}

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

/* ==========================================================================
   Page Header
   ========================================================================== */
.page-header {
	padding: var(--spacing-2xl) 0;
	border-bottom: 1px solid var(--color-border-light);
	margin-bottom: var(--spacing-2xl);
}

.page-title {
	margin-bottom: var(--spacing-sm);
}

.archive-description {
	font-size: 1.0625rem;
	color: var(--color-text-secondary);
}

/* ==========================================================================
   Blog / Archive Grid
   ========================================================================== */
.posts-grid {
	display: grid;
	gap: var(--spacing-xl);
}

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

.archive-card {
	display: flex;
	flex-direction: column;
	background-color: var(--color-card-bg);
	border: 1px solid var(--color-card-border);
	border-radius: var(--border-radius-lg);
	overflow: hidden;
	transition: box-shadow var(--transition-base), transform var(--transition-base);
}

.archive-card:hover {
	box-shadow: var(--shadow-md);
	transform: translateY(-2px);
}

.archive-card-image {
	display: block;
	aspect-ratio: 16 / 10;
	overflow: hidden;
}

.archive-card-image img {
	width: 100%;
	height: 100%;
	object-fit: cover;
	transition: transform var(--transition-slow);
}

.archive-card:hover .archive-card-image img {
	transform: scale(1.03);
}

.archive-card-body {
	padding: var(--spacing-xl);
	flex: 1;
	display: flex;
	flex-direction: column;
}

.archive-card-title {
	font-size: 1.25rem;
	margin-bottom: var(--spacing-sm);
	line-height: 1.35;
}

.archive-card-title a {
	color: var(--color-text);
	text-decoration: none;
}

.archive-card-title a:hover {
	color: var(--color-accent);
}

.archive-card-excerpt {
	font-size: 0.9375rem;
	color: var(--color-text-secondary);
	line-height: 1.6;
	flex: 1;
}

.archive-card .card-link {
	margin-top: var(--spacing-md);
}

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

@media (min-width: 992px) {
	.posts-grid-archive {
		grid-template-columns: 1fr;
	}

	.archive-card {
		flex-direction: row;
	}

	.archive-card-image {
		width: 280px;
		flex-shrink: 0;
		aspect-ratio: auto;
	}

	.archive-card-body {
		padding: var(--spacing-xl) var(--spacing-2xl);
	}
}

/* ==========================================================================
   Single Post
   ========================================================================== */
.single-content {
	max-width: var(--container-narrow);
	margin: 0 auto;
	padding: var(--spacing-2xl) var(--spacing-xl);
}

.single-header {
	margin-bottom: var(--spacing-2xl);
}

.single-meta {
	display: flex;
	align-items: center;
	gap: var(--spacing-sm);
	flex-wrap: wrap;
	margin-bottom: var(--spacing-lg);
	font-size: 0.875rem;
	color: var(--color-text-muted);
}

.meta-tag {
	padding: 3px 12px;
	border-radius: 20px;
	font-size: 0.75rem;
	font-weight: 600;
	text-transform: uppercase;
	letter-spacing: 0.03em;
}

.meta-topic {
	background-color: var(--color-accent-light);
	color: var(--color-accent);
	text-decoration: none;
}

.dark-mode .meta-topic {
	background-color: rgba(13, 148, 136, 0.15);
}

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

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

.single-title {
	font-size: 2.5rem;
	line-height: 1.2;
	letter-spacing: -0.02em;
	margin-bottom: var(--spacing-lg);
}

@media (max-width: 640px) {
	.single-title {
		font-size: 1.875rem;
	}
}

.single-featured-image {
	margin-bottom: var(--spacing-2xl);
	border-radius: var(--border-radius-lg);
	overflow: hidden;
}

.single-featured-image img {
	width: 100%;
	border-radius: var(--border-radius-lg);
}

/* Table of Contents */
.toc-placeholder {
	background-color: var(--color-bg-alt);
	border: 1px solid var(--color-border);
	border-radius: var(--border-radius-lg);
	padding: var(--spacing-xl);
	margin-bottom: var(--spacing-2xl);
}

.toc-title {
	font-size: 1rem;
	margin-bottom: var(--spacing-sm);
}

.toc-note {
	font-size: 0.8125rem;
	color: var(--color-text-muted);
	margin-bottom: var(--spacing-md);
}

.toc-list {
	display: flex;
	flex-direction: column;
	gap: var(--spacing-xs);
}

.toc-list a {
	display: block;
	padding: var(--spacing-xs) var(--spacing-md);
	font-size: 0.875rem;
	color: var(--color-text-secondary);
	border-left: 2px solid var(--color-border);
	text-decoration: none;
	transition: border-color var(--transition-fast), color var(--transition-fast);
}

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

/* Post Content Typography */
.entry-content {
	font-size: 1.0625rem;
	line-height: 1.8;
}

.entry-content h2 {
	font-size: 1.75rem;
	margin-top: var(--spacing-3xl);
	margin-bottom: var(--spacing-lg);
	padding-top: var(--spacing-lg);
	border-top: 1px solid var(--color-border-light);
}

.entry-content h3 {
	font-size: 1.375rem;
	margin-top: var(--spacing-2xl);
	margin-bottom: var(--spacing-md);
}

.entry-content h4 {
	font-size: 1.125rem;
	margin-top: var(--spacing-xl);
	margin-bottom: var(--spacing-md);
}

.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 ul {
	list-style: disc;
}

.entry-content ol {
	list-style: decimal;
}

.entry-content li {
	margin-bottom: var(--spacing-sm);
	padding-left: var(--spacing-sm);
}

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

.entry-content blockquote p:last-child {
	margin-bottom: 0;
}

.entry-content code {
	font-family: var(--font-mono);
	font-size: 0.875em;
	padding: 2px 6px;
	background-color: var(--color-code-bg);
	border-radius: 4px;
	color: var(--color-code-text);
}

.entry-content pre {
	background-color: var(--color-code-bg);
	border: 1px solid var(--color-border);
	border-radius: var(--border-radius);
	padding: var(--spacing-lg);
	margin: var(--spacing-xl) 0;
	overflow-x: auto;
	font-size: 0.875rem;
	line-height: 1.6;
}

.entry-content pre code {
	padding: 0;
	background: none;
	border-radius: 0;
}

.entry-content img {
	border-radius: var(--border-radius);
	margin: var(--spacing-xl) 0;
}

.entry-content a {
	text-decoration: underline;
	text-underline-offset: 2px;
	text-decoration-thickness: 1px;
}

.entry-content a:hover {
	text-decoration-thickness: 2px;
}

.entry-content table {
	width: 100%;
	border-collapse: collapse;
	margin: var(--spacing-xl) 0;
}

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

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

/* Post Tags */
.single-tags {
	display: flex;
	flex-wrap: wrap;
	gap: var(--spacing-sm);
	margin-top: var(--spacing-2xl);
	padding-top: var(--spacing-xl);
	border-top: 1px solid var(--color-border-light);
}

.tag-link {
	font-size: 0.875rem;
	color: var(--color-text-muted);
	text-decoration: none;
	padding: var(--spacing-xs) var(--spacing-md);
	border: 1px solid var(--color-border);
	border-radius: 20px;
	transition: all var(--transition-fast);
}

.tag-link:hover {
	color: var(--color-accent);
	border-color: var(--color-accent);
	background-color: var(--color-accent-light);
}

/* ==========================================================================
   Author Box
   ========================================================================== */
.author-box {
	display: flex;
	gap: var(--spacing-xl);
	padding: var(--spacing-xl);
	background-color: var(--color-bg-alt);
	border: 1px solid var(--color-border);
	border-radius: var(--border-radius-lg);
	margin-top: var(--spacing-2xl);
}

.author-avatar {
	flex-shrink: 0;
}

.author-avatar img {
	border-radius: 50%;
	width: 64px;
	height: 64px;
}

.author-name {
	font-size: 1rem;
	margin-bottom: var(--spacing-sm);
}

.author-bio {
	font-size: 0.9375rem;
	color: var(--color-text-secondary);
	line-height: 1.6;
	margin: 0;
}

/* ==========================================================================
   Post Navigation (Prev/Next)
   ========================================================================== */
.post-navigation {
	display: grid;
	gap: var(--spacing-md);
	margin-top: var(--spacing-2xl);
	padding-top: var(--spacing-xl);
	border-top: 1px solid var(--color-border-light);
}

@media (min-width: 640px) {
	.post-navigation {
		grid-template-columns: 1fr 1fr;
	}
}

.nav-prev,
.nav-next {
	display: flex;
	flex-direction: column;
	padding: var(--spacing-lg);
	background-color: var(--color-bg-alt);
	border: 1px solid var(--color-border);
	border-radius: var(--border-radius);
	text-decoration: none;
	transition: border-color var(--transition-fast);
}

.nav-prev:hover,
.nav-next:hover {
	border-color: var(--color-accent);
}

.nav-next {
	text-align: right;
}

.nav-label {
	font-size: 0.75rem;
	font-weight: 600;
	text-transform: uppercase;
	letter-spacing: 0.05em;
	color: var(--color-text-muted);
	margin-bottom: var(--spacing-xs);
}

.nav-title {
	font-size: 0.9375rem;
	font-weight: 600;
	color: var(--color-text);
	display: -webkit-box;
	-webkit-line-clamp: 2;
	-webkit-box-orient: vertical;
	overflow: hidden;
}

/* ==========================================================================
   Pagination
   ========================================================================== */
.pagination {
	display: flex;
	justify-content: center;
	align-items: center;
	gap: var(--spacing-sm);
	margin: var(--spacing-2xl) 0;
}

.pagination-num,
.pagination-current,
.pagination-prev,
.pagination-next {
	display: inline-flex;
	align-items: center;
	justify-content: center;
	min-width: 40px;
	height: 40px;
	padding: 0 var(--spacing-md);
	font-size: 0.9375rem;
	font-weight: 500;
	text-decoration: none;
	border: 1px solid var(--color-border);
	border-radius: var(--border-radius);
	color: var(--color-text-secondary);
	background-color: var(--color-bg);
	transition: all var(--transition-fast);
}

.pagination-num:hover {
	color: var(--color-accent);
	border-color: var(--color-accent);
	background-color: var(--color-accent-light);
}

.pagination-current {
	background-color: var(--color-accent);
	color: var(--color-accent-text);
	border-color: var(--color-accent);
	font-weight: 600;
}

/* ==========================================================================
   Sidebar
   ========================================================================== */
.sidebar {
	display: flex;
	flex-direction: column;
	gap: var(--spacing-xl);
}

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

.sidebar .widget-title {
	font-size: 1rem;
	margin-bottom: var(--spacing-md);
	padding-bottom: var(--spacing-sm);
	border-bottom: 2px solid var(--color-accent);
}

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

.sidebar .widget li {
	padding: var(--spacing-sm) 0;
	border-bottom: 1px solid var(--color-border-light);
	font-size: 0.9375rem;
}

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

.sidebar .widget a {
	color: var(--color-text-secondary);
	text-decoration: none;
}

.sidebar .widget a:hover {
	color: var(--color-accent);
}

/* ==========================================================================
   Comments
   ========================================================================== */
.comments-area {
	margin-top: var(--spacing-3xl);
	padding-top: var(--spacing-2xl);
	border-top: 1px solid var(--color-border);
}

.comments-title {
	font-size: 1.5rem;
	margin-bottom: var(--spacing-xl);
}

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

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

.comment-list .comment .comment-meta {
	display: flex;
	align-items: center;
	gap: var(--spacing-md);
	margin-bottom: var(--spacing-md);
}

.comment-list .comment .comment-author img {
	border-radius: 50%;
	margin-right: var(--spacing-sm);
}

.comment-list .comment .comment-metadata {
	font-size: 0.8125rem;
	color: var(--color-text-muted);
}

.comment-list .comment .comment-metadata a {
	color: var(--color-text-muted);
	text-decoration: none;
}

.comment-list .comment .comment-content {
	font-size: 0.9375rem;
	line-height: 1.7;
}

.comment-respond {
	margin-top: var(--spacing-2xl);
}

.comment-respond .comment-reply-title {
	font-size: 1.25rem;
	margin-bottom: var(--spacing-lg);
}

.comment-form label {
	display: block;
	font-size: 0.875rem;
	font-weight: 600;
	margin-bottom: var(--spacing-xs);
	color: var(--color-text);
}

.comment-form input[type="text"],
.comment-form input[type="email"],
.comment-form input[type="url"],
.comment-form textarea {
	width: 100%;
	padding: var(--spacing-md);
	font-size: 0.9375rem;
	font-family: var(--font-body);
	border: 1px solid var(--color-border);
	border-radius: var(--border-radius);
	background-color: var(--color-bg);
	color: var(--color-text);
	outline: none;
	transition: border-color var(--transition-fast);
}

.comment-form input:focus,
.comment-form textarea:focus {
	border-color: var(--color-accent);
}

.comment-form textarea {
	min-height: 150px;
	resize: vertical;
}

.comment-form .form-submit {
	margin-top: var(--spacing-md);
}

/* ==========================================================================
   404 Page
   ========================================================================== */
.error-404 {
	text-align: center;
	padding: var(--spacing-4xl) 0;
}

.error-code {
	display: block;
	font-family: var(--font-heading);
	font-size: 8rem;
	font-weight: 700;
	color: var(--color-border);
	line-height: 1;
	margin-bottom: var(--spacing-lg);
}

.error-content .page-title {
	margin-bottom: var(--spacing-md);
}

.error-message {
	font-size: 1.0625rem;
	color: var(--color-text-secondary);
	max-width: 480px;
	margin: 0 auto var(--spacing-2xl);
}

.error-search {
	max-width: 480px;
	margin: 0 auto var(--spacing-2xl);
}

.error-links {
	margin-top: var(--spacing-2xl);
}

.error-links h2 {
	font-size: 1.25rem;
	margin-bottom: var(--spacing-lg);
}

.error-links ul {
	list-style: none;
	display: flex;
	gap: var(--spacing-md);
	justify-content: center;
	flex-wrap: wrap;
}

.error-links a {
	padding: var(--spacing-sm) var(--spacing-lg);
	border: 1px solid var(--color-border);
	border-radius: var(--border-radius);
	color: var(--color-text-secondary);
	text-decoration: none;
	transition: all var(--transition-fast);
}

.error-links a:hover {
	color: var(--color-accent);
	border-color: var(--color-accent);
	background-color: var(--color-accent-light);
}

/* ==========================================================================
   No Results
   ========================================================================== */
.no-results {
	text-align: center;
	padding: var(--spacing-4xl) 0;
	max-width: 480px;
	margin: 0 auto;
}

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

.no-results p {
	color: var(--color-text-secondary);
	margin-bottom: var(--spacing-xl);
}

/* ==========================================================================
   Footer CTA Banner
   ========================================================================== */
.footer-cta-banner {
	background-color: var(--color-accent);
	color: var(--color-accent-text);
	padding: var(--spacing-3xl) 0;
	text-align: center;
}

.footer-cta-banner .cta-banner-title {
	color: var(--color-accent-text);
	margin-bottom: var(--spacing-sm);
}

.footer-cta-banner .cta-banner-text {
	color: rgba(255, 255, 255, 0.85);
	margin-bottom: var(--spacing-xl);
	max-width: 540px;
	margin-left: auto;
	margin-right: auto;
}

.footer-cta-banner .btn-primary {
	background-color: #ffffff;
	color: var(--color-accent);
	border-color: #ffffff;
}

.footer-cta-banner .btn-primary:hover {
	background-color: rgba(255, 255, 255, 0.9);
	color: var(--color-accent-hover);
}

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

.mt-0 { margin-top: 0; }
.mb-0 { margin-bottom: 0; }

/* ==========================================================================
   Print Styles
   ========================================================================== */
@media print {
	.site-header,
	.site-footer,
	.sidebar,
	.search-overlay,
	.pagination,
	.post-navigation,
	.newsletter-section,
	.footer-cta-banner,
	.dark-mode-toggle,
	.search-toggle,
	.mobile-menu-toggle {
		display: none !important;
	}

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

	.entry-content {
		font-size: 12pt;
	}

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

	.single-content {
		max-width: 100%;
		padding: 0;
	}
}

/* Crytodity Quant: restrained research-publication accents. */
.eyebrow { color: var(--color-accent); font-family: var(--font-mono); font-size: .73rem; font-weight: 700; letter-spacing: .12em; margin-bottom: 1rem; text-transform: uppercase; }
.quant-hero { background: linear-gradient(135deg, #f7faf9 0%, #fff 58%, #edf7f6 100%); border-bottom: 1px solid var(--color-border-light); }
.quant-hero .hero-content { max-width: 800px; }
.credibility-strip { border-bottom: 1px solid var(--color-border-light); background: var(--color-bg); }
.credibility-strip ul { display: grid; gap: 1rem; grid-template-columns: repeat(2, 1fr); list-style: none; margin: 0; padding: 1.25rem 0; }
.credibility-strip li { color: var(--color-text-secondary); font-size: .82rem; font-weight: 700; letter-spacing: .02em; }
.credibility-strip li::before { color: var(--color-accent); content: '— '; }
.category-index { color: var(--color-accent); display: block; font-family: var(--font-mono); font-size: .75rem; font-weight: 700; margin-bottom: 2rem; }
.strategy-categories { background: var(--color-bg-alt); }
.why-quant { border-top: 1px solid var(--color-border-light); }
.empty-state { color: var(--color-text-secondary); grid-column: 1 / -1; }
@media (min-width: 768px) { .credibility-strip ul { grid-template-columns: repeat(4, 1fr); } }