/* ─── Design Tokens ─── */

:root {
	color-scheme: light dark;

	/* Colors */
	--color-background: light-dark(#F6F8FA, #0d1117);
	--color-border: light-dark(#dbdde0, #21262d);
	--color-text: light-dark(#000000, #ffffff);
	--color-surface: light-dark(#ffffff, #000000);
	--color-subtle: light-dark(#666666, #888888);
	--color-links: light-dark(#555555, #999999);

	/* Typography */
	--font: 'Geist', sans-serif;
	--font-mono: 'Geist Mono', monospace;
	--type-hero-title: clamp(2.5rem, 8vw, 5rem);
	--type-hero-subtitle: clamp(1rem, 2.4vw, 1.5rem);
	--type-hero-line-height: 1.1;
	--type-mono-size: 0.9rem;
	--type-subheading-lg: clamp(1.5rem, 4vw, 2rem);
	--type-subheading-md: clamp(1.25rem, 3.5vw, 1.75rem);

	/* Layout */
	--space-xs: 0.25rem;
	--space-sm: 0.5rem;
	--space-md: 2rem;
	--space-lg: 8rem;
	--max-width: 56rem;
	--radius: 1rem;
	--border-width: 0.05rem;
}

/* ─── Theme Variables ─── */
[data-theme="dark"] {
	--color-background: #020510;
	--color-border: #2d2d3d;
	--color-text: #e4e4e7;
	--color-surface: #0f1420;
	--color-subtle: #888896;
	--color-links: #999999;
}

[data-theme="light"] {
	--color-background: #ffffff;
	--color-border: #e0e0e0;
	--color-text: #111111;
	--color-surface: #f6f6f6;
	--color-subtle: #888888;
	--color-links: #555555;
}

/* ─── Reset & Global Styles ─── */

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

html {
	scroll-behavior: smooth;
}

body {
	inline-size: 100%;
	padding-inline: var(--space-sm);
	padding-block: var(--space-sm);
	background-color: var(--color-background);
	color: var(--color-text);
	font-family: var(--font);
	font-size: 1.25rem;
	line-height: 1.35;
	letter-spacing: 0.02em;

	a {
		text-decoration: underline;
		color: var(--color-links);
		transition: opacity 0.2s ease;

		&:hover {
			opacity: 0.7;
		}
	}

	p {
		line-height: 1.35;
		letter-spacing: 0.02em;
	}

	h2,
	h3,
	h4 {
		font-family: var(--font);
	}
}

@keyframes growIn {
	0% {
		transform: scale(0.96);
	}

	100% {
		transform: scale(1);
	}
}

/* ─── Header & Navigation ─── */

header {
	margin-block-start: 0;
	margin-inline: auto;
	max-inline-size: 1200px;

	nav {
		display: flex;
		justify-content: space-between;
		align-items: center;
		padding-block: var(--space-sm);
		padding-inline: var(--space-md);
		background-color: var(--color-surface);
		font-family: var(--font);
		border-radius: var(--radius);
		border: var(--border-width) solid var(--color-border);
		position: sticky;
		top: var(--space-md);
		left: 0;
		right: 0;
		transform: scale(1);
		opacity: 1;
		z-index: 1000;
		transition: inline-size 0.45s ease, padding 0.45s ease, border-radius 0.45s ease, transform 0.35s ease, opacity 0.35s ease;
		margin-block-start: var(--space-md);
		margin-block-end: var(--space-md);
		margin-inline: auto;
		inline-size: min(calc(100% - (var(--space-sm) * 2)), 1200px);

		a {
			text-decoration: none;
		}

		.logo {
			font-weight: 500;
			z-index: 1001;
			font-family: var(--font-mono);
			text-transform: uppercase;
			text-decoration: none;
		}

		#menu-toggle {
			display: none;
			background: none;
			border: none;
			color: var(--color-text);
			cursor: pointer;
			padding: 0;
			font-size: 1.5rem;
			z-index: 1001;
			transition: opacity 0.2s ease;

			&:hover {
				opacity: 0.7;
			}
		}

		.menu {
			display: flex;
			flex-direction: row;
			gap: var(--space-md);
			list-style: none;

			li {
				display: flex;
				align-items: center;

				a {
					transition: opacity 0.2s ease;
					font-family: var(--font-mono);
					font-size: var(--type-mono-size);
					letter-spacing: 0.02em;
					text-transform: uppercase;
					text-decoration: none;
					color: var(--color-links);
				}
			}
		}

		#theme-switch {
			background: none;
			border: none;
			color: var(--color-text);
			cursor: pointer;
			padding: 0;
			border-radius: var(--radius);
			inline-size: auto;
			block-size: auto;
			display: inline-flex;
			align-items: center;
			justify-content: center;
			transition: opacity 0.2s ease;
			font-family: inherit;

			svg {
				fill: var(--color-text);
			}

			&:hover {
				opacity: 0.7;
			}
		}
	}

	/* Scrolled state - makes nav smaller */
	nav.scrolled {
		position: fixed;
		top: var(--space-md);
		left: 0;
		right: 0;
		transform: scale(0.97);
		opacity: 0.96;
		padding-block: var(--space-sm);
		padding-inline: var(--space-md);
		margin-inline: auto;
		margin-block: 0;
		border-radius: var(--radius);
		border: var(--border-width) solid var(--color-border);
		inline-size: min(calc(100% - (var(--space-md) * 2)), calc(var(--max-width) - 8rem));

		.logo {
			font-size: var(--type-mono-size);
		}

		.menu li a {
			font-size: var(--type-mono-size);
		}
	}

	/* Mobile menu */
	@media (width < 47.95rem) {
		nav {
			flex-wrap: wrap;

			#menu-toggle {
				display: block;
			}

			.menu {
				position: absolute;
				top: 100%;
				left: 0;
				right: 0;
				flex-direction: column;
				gap: 0;
				background-color: var(--color-surface);
				border: var(--border-width) solid var(--color-border);
				border-top: none;
				border-radius: 0 0 var(--radius) var(--radius);
				padding: var(--space-md);
				margin-top: var(--space-sm);
				display: none;

				&.active {
					display: flex;
				}

				li {
					inline-size: 100%;
					padding-block: var(--space-sm);

					a {
						display: block;
						inline-size: 100%;
					}
				}
			}
		}
	}

	hgroup {
		padding-block-start: clamp(1.5rem, 2vh, 2rem);
		padding-block-end: clamp(1rem, 2vh, 1.5rem);
		padding-inline: var(--space-md);
		display: flex;
		flex-direction: column;
		min-block-size: auto;
		justify-content: flex-start;
		gap: 1.5rem;

		.subtitle {
			margin-inline-start: 0;
			font-family: var(--font-mono);
			font-size: 0.75rem;
			font-weight: 400;
			letter-spacing: 0.05em;
			margin-block-end: 0;
			padding: 0;
			color: var(--color-subtle);

			&:empty {
				display: none;
			}
		}

		h1 {
			font-family: var(--font);
			font-size: clamp(2.5rem, 8vw, 5rem);
			line-height: 1.1;
			font-weight: 700;
			letter-spacing: -0.015em;
			margin: 0;
			padding: 0;
			margin-block-end: clamp(1.25rem, 2.5vw, 2rem);
			max-inline-size: 80%;
			-webkit-text-size-adjust: 100%;

			span {
				display: block;
			}
		}

		p {
			padding-block-start: 0;
			padding-block-end: 0;
			font-family: var(--font);
			font-size: clamp(0.9375rem, 2.1vw, 1.1875rem);
			line-height: 1.6;
			max-inline-size: 80ch;
			color: var(--color-text);
		}
	}
}

/* ─── Footer ─── */

footer {
	margin-block-start: var(--space-md);
	padding: var(--space-md);
	display: flex;
	flex-direction: column;
	margin-inline: auto;
	max-inline-size: 1200px;

	h3 {
		font-size: clamp(2rem, 6vw, 4rem);
		line-height: 0.95;
		font-weight: 700;
		margin-block-end: var(--space-sm);
	}

	> p {
		font-size: clamp(0.875rem, 2vw, 1.125rem);
		margin-block-end: var(--space-md);
	}

	.footer-menu-container {
		display: flex;
		flex-direction: column;
		gap: var(--space-md);
		overflow: hidden;

		.footer-menu,
		a {
			font-family: var(--font-mono);
			font-size: var(--type-mono-size);
			letter-spacing: 0.02em;
			text-transform: uppercase;
		}

		.footer-menu {
			display: flex;
			flex-direction: column;
			gap: var(--space-sm);
			list-style: none;

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

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

/* ─── Responsive Adjustments ─── */

/* Tablet - iPad */
@media (width > 35.95rem) {
	header nav {
		gap: var(--space-md);
	}

	p {
		max-inline-size: 60%;
	}

	footer {
		h3 {
			font-size: clamp(2rem, 6vw, 4rem);
		}

		> p {
			font-size: clamp(0.875rem, 2vw, 1.125rem);
			padding-block-end: var(--space-md);
		}

		.footer-menu-container {
			flex-direction: row;
			justify-content: space-between;
			align-items: center;
			gap: var(--space-md);

			.footer-menu {
				flex-direction: row;
				gap: var(--space-md);
			}
		}
	}
}