/* ---------------------------------------------------------------------------
   Base — fonts, reset, element defaults, layout primitives and utilities.
   Everything here is either an element selector or a single-purpose helper.
   Named UI pieces live in components.css.
   --------------------------------------------------------------------------- */

/* -- fonts ------------------------------------------------------------------
   Self-hosted, subset to Latin and box-drawing, from the same OFL files the
   app bundles. No third-party request is made from this site at any point:
   nothing to consent to, nothing to leak, nothing to break when a CDN does.
   font-display:swap renders in the fallback immediately rather than holding
   the first paint hostage to a 24 KB download. */

@font-face {
	font-family: "Barlow";
	src: url("../fonts/Barlow-Regular.woff2") format("woff2");
	font-weight: 400;
	font-style: normal;
	font-display: swap;
}

@font-face {
	font-family: "Barlow";
	src: url("../fonts/Barlow-Bold.woff2") format("woff2");
	font-weight: 700;
	font-style: normal;
	font-display: swap;
}

@font-face {
	font-family: "IBM Plex Mono";
	src: url("../fonts/IBMPlexMono-Regular.woff2") format("woff2");
	font-weight: 400;
	font-style: normal;
	font-display: swap;
}

@font-face {
	font-family: "IBM Plex Mono";
	src: url("../fonts/IBMPlexMono-Bold.woff2") format("woff2");
	font-weight: 700;
	font-style: normal;
	font-display: swap;
}

/* -- reset ---------------------------------------------------------------- */

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

* {
	margin: 0;
}

html {
	-webkit-text-size-adjust: 100%;
	/* Anchored sections must clear the sticky header. */
	scroll-padding-top: calc(var(--header-h) + var(--sp-5));
}

@media (prefers-reduced-motion: no-preference) {
	html {
		scroll-behavior: smooth;
	}
}

body {
	background-color: var(--bg);
	color: var(--txt);
	font-family: var(--font-ui);
	font-size: var(--fs-body);
	line-height: var(--lh-body);
	min-height: 100svh;
	-webkit-font-smoothing: antialiased;
	-moz-osx-font-smoothing: grayscale;
	/* The hero's glow bleeds wide; never let it open a horizontal scrollbar. */
	overflow-x: hidden;
}

img,
svg,
canvas,
video {
	display: block;
	max-width: 100%;
}

img {
	height: auto;
}

input,
button,
textarea,
select {
	font: inherit;
	color: inherit;
}

/* -- typography ----------------------------------------------------------- */

h1,
h2,
h3,
h4 {
	line-height: var(--lh-heading);
	font-weight: 700;
	text-wrap: balance;
	letter-spacing: -0.015em;
}

h1 {
	font-size: var(--fs-display);
	line-height: var(--lh-tight);
	letter-spacing: -0.03em;
}

h2 {
	font-size: var(--fs-h2);
	letter-spacing: -0.02em;
}

h3 {
	font-size: var(--fs-h3);
}

p {
	text-wrap: pretty;
}

a {
	color: var(--cyan);
	text-decoration-color: color-mix(in srgb, var(--cyan) 40%, transparent);
	text-underline-offset: 0.2em;
	transition: color var(--dur-fast) var(--ease),
		text-decoration-color var(--dur-fast) var(--ease);
}

a:hover {
	text-decoration-color: currentColor;
}

strong,
b {
	font-weight: 700;
	color: var(--txt);
}

code,
kbd,
samp,
pre {
	font-family: var(--font-mono);
	font-size: 0.9em;
}

/* Inline code — a quieter version of the app's readout panel. */
code {
	background-color: var(--panel-2);
	border: 1px solid var(--line-soft);
	border-radius: var(--r-sm);
	padding: 0.1em 0.4em;
	color: var(--txt);
	white-space: nowrap;
}

pre {
	font-size: var(--fs-sm);
	line-height: 1.7;
	overflow-x: auto;
	background-color: var(--panel);
	border: 1px solid var(--line);
	border-radius: var(--r-lg);
	padding: var(--sp-4) var(--sp-5);
	color: var(--txt-dim);
	/* A code block is horizontally scrollable, so it is a focusable region for
	   keyboard users who cannot drag it. */
	tab-size: 4;
}

pre code {
	background: none;
	border: 0;
	padding: 0;
	white-space: pre;
	font-size: inherit;
}

/* The shell prompt in a command block. Non-selectable so copying the block
   does not carry a "$" into the terminal. */
pre .prompt {
	color: var(--txt-faint);
	user-select: none;
	-webkit-user-select: none;
}

pre .comment {
	color: var(--txt-faint);
}

ul,
ol {
	padding-left: 1.25em;
}

li::marker {
	color: var(--txt-mut);
}

li + li {
	margin-top: var(--sp-2);
}

hr {
	border: 0;
	border-top: 1px solid var(--line-soft);
	margin: var(--sp-6) 0;
}

/* -- focus ---------------------------------------------------------------- */
/* One visible ring everywhere, on keyboard focus only. Never remove it. */

:focus-visible {
	outline: none;
	box-shadow: var(--focus-ring);
	border-radius: var(--r-sm);
}

/* -- selection ------------------------------------------------------------ */

::selection {
	background-color: color-mix(in srgb, var(--cyan) 30%, transparent);
	color: var(--txt);
}

/* -- scrollbar ------------------------------------------------------------
   The same treatment the app gives its rail: a thin rounded thumb on no
   track, rather than a foreign widget bolted onto a dark surface. */

* {
	scrollbar-width: thin;
	scrollbar-color: #23303e transparent;
}

::-webkit-scrollbar {
	width: 11px;
	height: 11px;
}

::-webkit-scrollbar-track {
	background: transparent;
}

::-webkit-scrollbar-thumb {
	background-color: #23303e;
	border-radius: var(--r-sm);
	border: 3px solid transparent;
	background-clip: content-box;
}

::-webkit-scrollbar-thumb:hover {
	background-color: #33475b;
	background-clip: content-box;
}

/* -- layout primitives ---------------------------------------------------- */

.container {
	width: 100%;
	max-width: var(--container);
	margin-inline: auto;
	padding-inline: var(--gutter);
}

.container--narrow {
	max-width: var(--container-narrow);
}

/* A major page section. Sections alternate nothing — separation comes from
   the hairline rules and panels, not from alternating background bands. */
.section {
	padding-block: var(--section-y);
}

.section--tight {
	padding-block: calc(var(--section-y) * 0.6);
}

/* A hairline above the section, matching the app's .section border. */
.section--ruled {
	border-top: 1px solid var(--line-soft);
}

/* -- utilities ------------------------------------------------------------ */

.stack > * + * {
	margin-top: var(--flow, var(--sp-4));
}

.measure {
	max-width: var(--measure);
}

.center {
	margin-inline: auto;
	text-align: center;
}

.center .measure,
.measure.center {
	margin-inline: auto;
}

.mono {
	font-family: var(--font-mono);
}

.dim {
	color: var(--txt-dim);
}

.mut {
	color: var(--txt-mut);
}

.lead {
	font-size: var(--fs-body-lg);
	color: var(--txt-dim);
}

.t-cyan {
	color: var(--cyan);
}

.t-amber {
	color: var(--amber);
}

.t-lime {
	color: var(--lime);
}

/* Top margin, on the same scale as the tokens. Deliberately a small, closed
   set rather than a full spacing framework: if a layout needs something these
   do not cover, the block it belongs to should own the rule instead. */
.mt-2 {
	margin-top: var(--sp-2);
}
.mt-4 {
	margin-top: var(--sp-4);
}
.mt-5 {
	margin-top: var(--sp-5);
}
.mt-6 {
	margin-top: var(--sp-6);
}
.mt-7 {
	margin-top: var(--sp-7);
}
.mt-8 {
	margin-top: var(--sp-8);
}

/* -- accents --------------------------------------------------------------
   --accent is the one property a component takes as an argument: .card,
   .card__dot, .feature__icon and .callout all read it. Setting it with a
   class rather than a style attribute keeps the pages free of inline CSS, so
   the site can be served under a strict Content-Security-Policy with no
   'unsafe-inline'. Custom properties inherit, so setting it on a card is
   enough for everything inside it. */

.acc-cyan {
	--accent: var(--cyan);
}
.acc-amber {
	--accent: var(--amber);
}
.acc-lime {
	--accent: var(--lime);
}
.acc-red {
	--accent: var(--red);
}
.acc-mut {
	--accent: var(--txt-mut);
}
.acc-mid {
	--accent: var(--zone-mid);
}
.acc-low-mid {
	--accent: var(--zone-low-mid);
}

/* Visually hidden but read by assistive tech. */
.visually-hidden {
	position: absolute;
	width: 1px;
	height: 1px;
	padding: 0;
	margin: -1px;
	overflow: hidden;
	clip-path: inset(50%);
	white-space: nowrap;
	border: 0;
}

/* -- motion --------------------------------------------------------------- */
/* Honour the OS setting: no transitions, no animation, no smooth scroll.
   The spectrum canvas checks the same query in JS and paints one static
   frame instead of running its loop. */

@media (prefers-reduced-motion: reduce) {
	*,
	*::before,
	*::after {
		animation-duration: 0.01ms !important;
		animation-iteration-count: 1 !important;
		transition-duration: 0.01ms !important;
		scroll-behavior: auto !important;
	}
}