/* Portfolio — AI / Backend / Systems Engineer theme */

:root {
	--bg-primary: #0f1117;
	--bg-secondary: #161b26;
	--bg-card: #1c2230;
	--bg-card-hover: #222a3a;
	--border: #2a3344;
	--text-primary: #e8eaef;
	--text-secondary: #9aa3b5;
	--text-muted: #6b7589;
	--accent: #3b82f6;
	--accent-hover: #2563eb;
	--accent-muted: rgba(59, 130, 246, 0.12);
	--font-sans: "Inter", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
	--font-mono: "JetBrains Mono", "Fira Code", ui-monospace, monospace;
	--nav-height: 4rem;
	--section-padding: 5rem;
	--container-max: 72rem;
	--prose-max: 52rem;
	--radius: 0.5rem;
	--radius-lg: 0.75rem;
	--shadow: 0 4px 24px rgba(0, 0, 0, 0.35);
	--transition: 0.2s ease;
}

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

html {
	scroll-behavior: smooth;
	scroll-padding-top: var(--nav-height);
}

body {
	margin: 0;
	font-family: var(--font-sans);
	font-size: 1rem;
	line-height: 1.65;
	color: var(--text-primary);
	background: var(--bg-primary);
	-webkit-font-smoothing: antialiased;
}

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

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

a:hover {
	color: #60a5fa;
}

.container {
	width: 100%;
	max-width: var(--container-max);
	margin: 0 auto;
	padding: 0 1.5rem;
}

/* Navigation */

.site-nav {
	position: fixed;
	top: 0;
	left: 0;
	right: 0;
	z-index: 1000;
	height: var(--nav-height);
	background: rgba(15, 17, 23, 0.92);
	backdrop-filter: blur(12px);
	border-bottom: 1px solid var(--border);
}

.site-nav .container {
	display: flex;
	align-items: center;
	justify-content: space-between;
	height: 100%;
}

.nav-brand {
	font-weight: 600;
	font-size: 1rem;
	color: var(--text-primary);
	letter-spacing: -0.02em;
}

.nav-brand:hover {
	color: var(--accent);
}

.nav-links {
	display: flex;
	align-items: center;
	gap: 0.25rem;
	list-style: none;
	margin: 0;
	padding: 0;
}

.nav-links a {
	display: block;
	padding: 0.5rem 0.875rem;
	font-size: 0.875rem;
	font-weight: 500;
	color: var(--text-secondary);
	border-radius: var(--radius);
}

.nav-links a:hover,
.nav-links a.active {
	color: var(--text-primary);
	background: var(--accent-muted);
}

.nav-toggle {
	display: none;
	flex-direction: column;
	justify-content: center;
	gap: 5px;
	width: 2.5rem;
	height: 2.5rem;
	padding: 0;
	border: 1px solid var(--border);
	border-radius: var(--radius);
	background: var(--bg-card);
	cursor: pointer;
}

.nav-toggle span {
	display: block;
	width: 18px;
	height: 2px;
	margin: 0 auto;
	background: var(--text-primary);
	border-radius: 1px;
	transition: transform var(--transition), opacity var(--transition);
}

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

.nav-toggle[aria-expanded="true"] span:nth-child(2) {
	opacity: 0;
}

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

/* Sections */

.section {
	padding: var(--section-padding) 0;
}

.section--hero {
	padding-top: calc(var(--nav-height) + 4rem);
	padding-bottom: 5rem;
	min-height: 85vh;
	display: flex;
	align-items: center;
	background:
		radial-gradient(ellipse 80% 50% at 50% -20%, rgba(59, 130, 246, 0.15), transparent),
		var(--bg-primary);
}

.section--alt {
	background: var(--bg-secondary);
	border-top: 1px solid var(--border);
	border-bottom: 1px solid var(--border);
}

.section-header {
	margin-bottom: 2.5rem;
}

.section-header h2 {
	margin: 0 0 0.5rem;
	font-size: clamp(1.75rem, 4vw, 2.25rem);
	font-weight: 700;
	letter-spacing: -0.03em;
	color: var(--text-primary);
}

.section-header p {
	margin: 0;
	font-size: 1.0625rem;
	color: var(--text-secondary);
	max-width: var(--prose-max);
}

/* Hero */

.hero-label {
	display: inline-block;
	margin-bottom: 1rem;
	padding: 0.4rem 0.875rem;
	font-size: 0.8125rem;
	font-weight: 600;
	letter-spacing: 0.06em;
	text-transform: uppercase;
	color: var(--accent);
	background: var(--accent-muted);
	border: 1px solid rgba(59, 130, 246, 0.25);
	border-radius: 999px;
}

.hero h1 {
	margin: 0 0 1.5rem;
	font-size: clamp(2.25rem, 5.5vw, 3.375rem);
	font-weight: 700;
	line-height: 1.15;
	letter-spacing: -0.03em;
}

.hero h1 strong {
	color: var(--text-primary);
	font-weight: 700;
}

.hero-lead {
	margin: 0 0 2rem;
	font-size: 1.25rem;
	color: var(--text-secondary);
	max-width: 54rem;
	line-height: 1.7;
}

.hero-meta {
	margin: 0 0 2rem;
	font-size: 1rem;
	color: var(--text-muted);
}

.hero-actions {
	display: flex;
	flex-wrap: wrap;
	gap: 0.75rem;
}

.hero .btn {
	font-size: 1rem;
	padding: 0.875rem 1.375rem;
}

/* Buttons */

.btn {
	display: inline-flex;
	align-items: center;
	justify-content: center;
	gap: 0.5rem;
	padding: 0.75rem 1.25rem;
	font-family: inherit;
	font-size: 0.9375rem;
	font-weight: 600;
	line-height: 1;
	border-radius: var(--radius);
	border: 1px solid transparent;
	cursor: pointer;
	transition: background var(--transition), border-color var(--transition), color var(--transition);
}

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

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

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

.btn--secondary:hover {
	background: var(--bg-card-hover);
	border-color: #3d4a63;
	color: var(--text-primary);
}

.btn--ghost {
	color: var(--text-secondary);
	background: transparent;
	border-color: var(--border);
}

.btn--ghost:hover {
	color: var(--text-primary);
	border-color: #3d4a63;
	background: var(--bg-card);
}

/* Cards — About */

.card-grid {
	display: grid;
	grid-template-columns: repeat(3, 1fr);
	gap: 1.5rem;
}

.card {
	padding: 1.75rem;
	background: var(--bg-card);
	border: 1px solid var(--border);
	border-radius: var(--radius-lg);
	transition: border-color var(--transition), background var(--transition);
}

.card:hover {
	background: var(--bg-card-hover);
	border-color: #3d4a63;
}

.card-icon {
	display: flex;
	align-items: center;
	justify-content: center;
	width: 2.75rem;
	height: 2.75rem;
	margin-bottom: 1.25rem;
	font-size: 1.125rem;
	color: var(--accent);
	background: var(--accent-muted);
	border-radius: var(--radius);
}

.card h3 {
	margin: 0 0 0.75rem;
	font-size: 1.125rem;
	font-weight: 600;
	letter-spacing: -0.02em;
}

.card p {
	margin: 0;
	font-size: 0.9375rem;
	color: var(--text-secondary);
	line-height: 1.65;
}

/* Project cards */

.project-grid {
	display: grid;
	grid-template-columns: repeat(2, 1fr);
	gap: 1.5rem;
}

.project-card {
	display: flex;
	flex-direction: column;
	padding: 1.75rem;
	background: var(--bg-card);
	border: 1px solid var(--border);
	border-radius: var(--radius-lg);
	transition: border-color var(--transition), box-shadow var(--transition);
}

.project-card:hover {
	border-color: rgba(59, 130, 246, 0.35);
	box-shadow: var(--shadow);
}

.project-card h3 {
	margin: 0 0 0.75rem;
	font-size: 1.25rem;
	font-weight: 600;
	letter-spacing: -0.02em;
}

.project-card .description {
	margin: 0 0 1rem;
	font-size: 0.9375rem;
	color: var(--text-secondary);
	flex-grow: 1;
}

.project-highlights {
	margin: 0 0 1.25rem;
	padding: 0;
	list-style: none;
}

.project-highlights li {
	position: relative;
	padding-left: 1.125rem;
	margin-bottom: 0.35rem;
	font-size: 0.8125rem;
	color: var(--text-muted);
	line-height: 1.5;
}

.project-highlights li::before {
	content: "";
	position: absolute;
	left: 0;
	top: 0.55em;
	width: 4px;
	height: 4px;
	background: var(--accent);
	border-radius: 50%;
}

.tag-list {
	display: flex;
	flex-wrap: wrap;
	gap: 0.4rem;
	margin-bottom: 1.25rem;
}

.tag {
	padding: 0.2rem 0.55rem;
	font-size: 0.75rem;
	font-family: var(--font-mono);
	font-weight: 500;
	color: var(--text-secondary);
	background: var(--bg-secondary);
	border: 1px solid var(--border);
	border-radius: 4px;
}

.project-card .btn {
	align-self: flex-start;
	margin-top: auto;
}

/* Skills */

.skills-grid {
	display: grid;
	grid-template-columns: repeat(3, 1fr);
	gap: 1.5rem;
}

.skill-card h3 {
	margin: 0 0 1.25rem;
	padding-bottom: 0.75rem;
	font-size: 1rem;
	font-weight: 600;
	color: var(--text-primary);
	border-bottom: 1px solid var(--border);
}

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

.skill-list li {
	display: flex;
	align-items: center;
	gap: 0.625rem;
	padding: 0.4rem 0;
	font-size: 0.9375rem;
	color: var(--text-secondary);
}

.skill-list li i,
.skill-list li img {
	flex-shrink: 0;
	width: 1.25rem;
	text-align: center;
	color: var(--accent);
}

.skill-list li img {
	width: 1.25rem;
	height: 1.25rem;
}

.skill-list--concepts li::before {
	content: "▸";
	color: var(--accent);
	font-size: 0.75rem;
}

.skill-list--concepts li {
	padding-left: 0;
	gap: 0.5rem;
}

/* Contact */

.contact-block {
	text-align: center;
	max-width: 40rem;
	margin: 0 auto;
}

.contact-block h2 {
	margin: 0 0 0.75rem;
	font-size: 1.75rem;
	font-weight: 700;
}

.contact-block > p {
	margin: 0 0 2rem;
	color: var(--text-secondary);
}

.contact-actions {
	display: flex;
	flex-wrap: wrap;
	justify-content: center;
	gap: 0.75rem;
	margin-bottom: 2.5rem;
}

.social-links {
	display: flex;
	justify-content: center;
	gap: 0.75rem;
	list-style: none;
	margin: 0;
	padding: 0;
}

.social-links a {
	display: flex;
	align-items: center;
	justify-content: center;
	width: 2.75rem;
	height: 2.75rem;
	font-size: 1.125rem;
	color: var(--text-secondary);
	background: var(--bg-card);
	border: 1px solid var(--border);
	border-radius: var(--radius);
	transition: color var(--transition), border-color var(--transition), background var(--transition);
}

.social-links a:hover {
	color: var(--accent);
	border-color: rgba(59, 130, 246, 0.4);
	background: var(--accent-muted);
}

.site-footer {
	padding: 2rem 0;
	text-align: center;
	font-size: 0.8125rem;
	color: var(--text-muted);
	border-top: 1px solid var(--border);
}

.site-footer ul {
	list-style: none;
	margin: 0;
	padding: 0;
	display: flex;
	flex-wrap: wrap;
	justify-content: center;
	gap: 0.5rem 1rem;
}

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

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

/* Section footer CTA */

.section-cta {
	margin-top: 2.5rem;
	text-align: center;
}

/* Responsive */

@media (max-width: 900px) {
	.card-grid,
	.skills-grid {
		grid-template-columns: 1fr;
	}

	.project-grid {
		grid-template-columns: 1fr;
	}
}

@media (max-width: 736px) {
	:root {
		--section-padding: 3.5rem;
	}

	.nav-toggle {
		display: flex;
	}

	.nav-links {
		position: fixed;
		top: var(--nav-height);
		left: 0;
		right: 0;
		flex-direction: column;
		align-items: stretch;
		gap: 0;
		padding: 0.75rem;
		background: var(--bg-secondary);
		border-bottom: 1px solid var(--border);
		transform: translateY(-100%);
		opacity: 0;
		visibility: hidden;
		transition: transform var(--transition), opacity var(--transition), visibility var(--transition);
	}

	.nav-links.is-open {
		transform: translateY(0);
		opacity: 1;
		visibility: visible;
	}

	.nav-links a {
		padding: 0.875rem 1rem;
	}

	.hero-actions .btn {
		width: 100%;
	}

	.contact-actions .btn {
		width: 100%;
	}
}

@media (prefers-reduced-motion: reduce) {
	html {
		scroll-behavior: auto;
	}

	*,
	*::before,
	*::after {
		transition-duration: 0.01ms !important;
	}
}