/* ============================================================
   Fonts — ABC Diatype Edu (maps to template's "Diatype")
   ============================================================ */
@font-face {
	font-family: "Diatype";
	src: url("fonts/ABCDiatypeEdu-Regular.woff2") format("woff2");
	font-weight: 400;
	font-style: normal;
	font-display: block;
}
@font-face {
	font-family: "Diatype";
	src: url("fonts/ABCDiatypeEdu-RegularItalic.woff2") format("woff2");
	font-weight: 400;
	font-style: italic;
	font-display: block;
}

/* ============================================================
   Custom properties
   ============================================================ */
:root {
	/* Desktop root size: a steady 11px (consistent at every desktop width). */
	--base-size: 11px;

	/* page background (light neutral grey content surface) */
	--page-bg: #f1f1f0;

	/* opacity-step swatches over black */
	--swatch-1: rgba(0, 0, 0, 0.85);
	--swatch-2: rgba(0, 0, 0, 0.75);

	/* spacing */
	--page-padding: 3.5rem;   /* .page-content padding */
	--column-max: 50%;        /* .page-content max-width */
	--border-width: 1px;

	/* derived header clearance (see .page.active padding):
	   page_padding(top) + name line-box(1.5*1.2=1.8rem) + hr(margin .5 + 1px + margin .5)
	   + one-line gap below the rule. */
	--header-clear: 7rem;
}

/* ============================================================
   Reset / base
   ============================================================ */
*, *::before, *::after { box-sizing: border-box; }

html, body {
	margin: 0;
	padding: 0;
	min-height: 100%;
	/* paint the page color all the way out so iOS safe-area insets and
	   overscroll/rubber-banding show the page background, not white */
	background-color: var(--page-bg);
}

html {
	font-size: var(--base-size);
	-webkit-text-size-adjust: none;
}

body {
	-webkit-font-smoothing: antialiased;
	-moz-osx-font-smoothing: grayscale;
	font-family: "Diatype", -apple-system, BlinkMacSystemFont, "Helvetica Neue", Arial, sans-serif;
}

a { color: inherit; }

/* ============================================================
   Content surface
   ============================================================ */
.content {
	position: relative;
	min-height: 100vh;
	min-height: 100svh;
	/* dvh tracks the *live* viewport, so centering stays correct as the
	   mobile/in-app browser toolbar expands or collapses */
	min-height: 100dvh;
	background-color: var(--page-bg);
}

/* ------------------------------------------------------------
   Header — fixed to the top of the viewport, overlapping the
   page content beneath it.
   ------------------------------------------------------------ */
.site-header {
	position: fixed;
	top: 0;
	left: 0;
	right: 0;
	z-index: 10;
	/* solid fill so page content scrolls up and vanishes exactly at the rule */
	background-color: var(--page-bg);
}

/* centered content column, shared by the header and every page */
.page-content {
	width: 100%;
	max-width: var(--column-max);
	margin: 0 auto;
	padding: var(--page-padding);
}

/* header row: name on the left, nav pushed to the right */
.header-row {
	display: flex;
	align-items: baseline;
	gap: 12px;
}

.site-name {
	flex: 0 1 auto;
	font-size: 1.5rem;
	line-height: 1.2;
	color: var(--swatch-1);
	letter-spacing: 0;
	white-space: nowrap;
}

.site-nav {
	flex: 1 1 auto;
	display: flex;
	justify-content: flex-end;
	gap: 1.4em;
	font-size: 1.5rem;
	line-height: 1.2;
	white-space: nowrap;
}

/* nav links: never underlined, lighten on hover */
.site-nav a {
	color: var(--swatch-1);
	text-decoration: none;
	transition: opacity 120ms ease;
}

.site-nav a:hover {
	opacity: 0.55;
}

hr {
	background: var(--swatch-2);
	border: 0;
	height: var(--border-width);
	display: block;
	margin: 0.5rem 0;
}

/* The header fill must stop exactly at the rule, with nothing painted below
   it — so content sliding up disappears right at the line. */
.site-header .page-content { padding-bottom: 0; }
.site-header hr { margin-bottom: 0; }

/* ------------------------------------------------------------
   Pages
   ------------------------------------------------------------ */
.page { display: none; }

/* Active pane fills the viewport. The top padding clears the fixed header;
   with no bottom padding, the content vertically centers within the space
   below the rule (header bottom → viewport bottom) rather than the whole page. */
.page.active {
	display: flex;
	flex-direction: column;
	justify-content: center;   /* vertical centering */
	align-items: center;       /* horizontal centering of the column */
	box-sizing: border-box;
	width: 100%;
	min-height: 100vh;
	min-height: 100svh;
	padding: var(--header-clear) 0 0;
}

/* the pane's own vertical padding is handled by .page above; keep only the
   left/right gutter here so the column doesn't touch the viewport edges */
.pages .page-content {
	padding-top: 0;
	padding-bottom: 0;
}

/* ------------------------------------------------------------
   Typography — body content
   ------------------------------------------------------------ */

bodycopy {
	display: block;
	font-size: 1.5rem;
	font-weight: 400;
	line-height: 1.2;
	letter-spacing: 0;
	color: var(--swatch-1);
	max-width: 100%;
	word-wrap: break-word;
}

/* all other links: dotted underline, lighten on hover */
bodycopy a {
	color: var(--swatch-1);
	text-decoration: underline dotted;
	text-underline-offset: 0.12em;
	transition: opacity 120ms ease;
}

bodycopy a:hover {
	opacity: 0.55;
}

bodycopy i { font-style: italic; }

a:active,
bodycopy a:active {
	opacity: 0.7;
}

/* bullets sit at the text's left edge (inline with the heading/body),
   with a larger marker and a hanging indent so wrapped lines line up */
ul {
	margin: 0;
	padding: 0;
	list-style: none;
}

li {
	margin: 0;
	padding-left: 0.9em;          /* item text + wrapped lines hang here */
}

li::before {
	content: "•";
	display: inline-block;
	width: 0.9em;                 /* marker box spans back to the text margin */
	margin-left: -0.9em;          /* left edge sits at the heading/text left edge */
	transform: scale(1.55);       /* enlarge the bullet without disturbing layout */
	transform-origin: 0% 50%;
}

/* ============================================================
   Mobile — <= 800px
   The column fills the viewport and the header moves into normal
   flow (no overlap). The root size is reduced so the name + nav
   stay together on a single line at phone widths.
   ============================================================ */
@media (max-width: 800px) {
	:root {
		--base-size: 10px;            /* 10pt mobile text */
		--column-max: 100%;           /* column fills the viewport */
		--page-padding: 2.5rem;       /* roomier mobile gutter */
	}

	.site-header {
		position: static;
	}

	/* header is in normal flow on mobile (no overlap), so keep its original
	   spacing below the rule */
	.site-header .page-content { padding-bottom: var(--page-padding); }
	.site-header hr { margin-bottom: 0.5rem; }

	.header-row {
		/* keep one line; wrap only as a last resort on very narrow screens */
		flex-wrap: wrap;
		row-gap: 0.3rem;
	}

	.site-nav {
		gap: 1em;                     /* tighten link spacing to help one-line fit */
	}

	/* The header is in normal flow on mobile, so vertically center the page
	   content within the space that remains beneath it: make .content a flex
	   column, let .pages take the leftover height, and center inside it.
	   Short pages center; long pages grow and scroll (top-aligned). */
	.content {
		display: flex;
		flex-direction: column;
	}

	.pages {
		flex: 1 1 auto;
		display: flex;
		flex-direction: column;
	}

	.page.active {
		flex: 1 1 auto;
		justify-content: center;   /* vertical centering in the remaining space */
		min-height: 0;
		padding: 0;
	}

	.pages .page-content {
		padding-top: var(--page-padding);
		padding-bottom: var(--page-padding);
	}
}

/* ============================================================
   Small mobile — <= 480px
   ============================================================ */
@media (max-width: 480px) {
	:root {
		--base-size: 10px;
		--page-padding: 2.25rem;
	}
}