/*
 * Base layer: document, typography, layout shells, header and footer.
 */

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

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

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

	*,
	*::before,
	*::after {
		animation-duration: 0.01ms !important;
		animation-iteration-count: 1 !important;
		transition-duration: 0.01ms !important;
	}
}

body {
	margin: 0;
	background: var(--bg);
	color: var(--ink);
	font-family: var(--font-sans);
	font-size: var(--text-base);
	line-height: var(--leading-normal);
	-webkit-font-smoothing: antialiased;
	-moz-osx-font-smoothing: grayscale;
	overflow-x: hidden;
}

h1,
h2,
h3,
h4,
h5,
h6 {
	margin: 0 0 var(--space-3);
	font-weight: 640;
	line-height: var(--leading-tight);
	letter-spacing: var(--tracking-tight);
	color: var(--ink);
	text-wrap: balance;
}

h1 {
	font-size: var(--text-3xl);
}

h2 {
	font-size: var(--text-2xl);
}

h3 {
	font-size: var(--text-xl);
}

h4 {
	font-size: var(--text-lg);
}

p {
	margin: 0 0 var(--space-4);
	color: var(--ink-soft);
	max-width: 68ch;
}

p:last-child {
	margin-bottom: 0;
}

a {
	color: var(--accent);
	text-decoration-thickness: 1px;
	text-underline-offset: 2px;
}

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

ul,
ol {
	margin: 0 0 var(--space-4);
	padding-left: 1.25em;
	color: var(--ink-soft);
}

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

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

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

code,
kbd {
	font-family: var(--font-mono);
	font-size: 0.92em;
	background: var(--surface-subtle);
	border: 1px solid var(--line);
	border-radius: 5px;
	padding: 0.1em 0.35em;
}

/* Focus is always visible and never removed. */
:focus-visible {
	outline: none;
	box-shadow: var(--focus-ring);
	border-radius: var(--radius-sm);
}

.isa-skip-link {
	position: absolute;
	left: -9999px;
	top: 0;
	z-index: 100;
	background: var(--accent);
	color: var(--accent-ink);
	padding: var(--space-3) var(--space-4);
	border-radius: 0 0 var(--radius-md) 0;
	font-weight: 600;
}

.isa-skip-link:focus {
	left: 0;
}

.isa-visually-hidden {
	position: absolute !important;
	width: 1px;
	height: 1px;
	margin: -1px;
	padding: 0;
	overflow: hidden;
	clip: rect(0 0 0 0);
	clip-path: inset(50%);
	white-space: nowrap;
	border: 0;
}

/* ---------------------------------------------------------------- Layout */

.isa-container {
	width: 100%;
	max-width: var(--container);
	margin: 0 auto;
	padding: 0 var(--space-4);
}

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

@media (min-width: 768px) {
	.isa-container {
		padding: 0 var(--space-6);
	}
}

.isa-section {
	padding: var(--space-6) 0;
}

.isa-section--tight {
	padding: var(--space-5) 0;
}

@media (min-width: 768px) {
	.isa-section {
		padding: var(--space-7) 0;
	}
}

.isa-stack > * + * {
	margin-top: var(--space-4);
}

.isa-stack--tight > * + * {
	margin-top: var(--space-2);
}

.isa-stack--loose > * + * {
	margin-top: var(--space-6);
}

/*
 * Grid columns use minmax(0, 1fr) and children get min-width: 0. Without
 * that, one long unbreakable line inside a card, such as a settings path,
 * stretches the column past the screen and phones zoom the whole page out.
 */
.isa-grid {
	display: grid;
	gap: var(--space-4);
	grid-template-columns: minmax(0, 1fr);
}

.isa-grid > *,
.isa-split > * {
	min-width: 0;
}

@media (min-width: 640px) {
	.isa-grid--2 {
		grid-template-columns: repeat(2, minmax(0, 1fr));
	}
}

@media (min-width: 900px) {
	.isa-grid--3 {
		grid-template-columns: repeat(3, minmax(0, 1fr));
	}

	.isa-grid--4 {
		grid-template-columns: repeat(4, minmax(0, 1fr));
	}

	.isa-grid--2 {
		grid-template-columns: repeat(2, minmax(0, 1fr));
	}
}

@media (min-width: 640px) and (max-width: 899px) {
	.isa-grid--3,
	.isa-grid--4 {
		grid-template-columns: repeat(2, minmax(0, 1fr));
	}
}

.isa-split {
	display: grid;
	gap: var(--space-6);
	grid-template-columns: 1fr;
	align-items: start;
}

@media (min-width: 960px) {
	.isa-split {
		grid-template-columns: minmax(0, 1fr) 320px;
	}
}

.isa-eyebrow {
	font-size: var(--text-xs);
	font-weight: 640;
	letter-spacing: var(--tracking-wide);
	text-transform: uppercase;
	color: var(--muted);
	margin-bottom: var(--space-2);
}

.isa-lead {
	font-size: var(--text-lg);
	line-height: var(--leading-snug);
	color: var(--ink-soft);
	max-width: 62ch;
}

.isa-muted {
	color: var(--muted);
	font-size: var(--text-sm);
}

/* ---------------------------------------------------------------- Header */

/*
 * Layout by width:
 *   under 600px   brand, device pill, search, menu
 *   600px up      adds the appearance button and the iOS version in the pill
 *   1200px up     full navigation replaces the menu button
 * Everything sits on one row and nothing is allowed to overflow it.
 */

.isa-header {
	position: sticky;
	top: 0;
	z-index: 40;
	background: var(--surface);
	border-bottom: 1px solid var(--line);
}

@supports (backdrop-filter: blur(10px)) {
	.isa-header {
		background: color-mix(in srgb, var(--surface) 92%, transparent);
		backdrop-filter: saturate(1.4) blur(10px);
	}
}

.isa-header__bar {
	display: flex;
	align-items: center;
	gap: var(--space-2);
	width: 100%;
	max-width: 1280px;
	min-height: 60px;
	margin: 0 auto;
	padding: var(--space-2) var(--space-4);
}

@media (min-width: 768px) {
	.isa-header__bar {
		gap: var(--space-3);
		min-height: 68px;
		padding: var(--space-2) var(--space-6);
	}
}

.isa-brand {
	display: inline-flex;
	align-items: center;
	gap: var(--space-2);
	flex: 0 0 auto;
	min-height: 44px;
	font-weight: 700;
	font-size: 1.0625rem;
	letter-spacing: var(--tracking-tight);
	color: var(--ink);
	text-decoration: none;
	white-space: nowrap;
}

.isa-brand:hover {
	color: var(--ink);
}

.isa-brand__mark {
	width: 28px;
	height: 28px;
	border-radius: 8px;
	background: var(--accent);
	display: grid;
	place-items: center;
	color: var(--accent-ink);
	font-size: 14px;
	font-weight: 700;
	letter-spacing: 0;
	flex: 0 0 auto;
}

/* On the narrowest phones the mark alone identifies the site. */
@media (max-width: 359px) {
	.isa-brand__name {
		position: absolute;
		width: 1px;
		height: 1px;
		overflow: hidden;
		clip: rect(0 0 0 0);
		white-space: nowrap;
	}
}

/* Full navigation, wide screens only. */
.isa-nav {
	display: none;
	min-width: 0;
}

.isa-nav ul {
	display: flex;
	align-items: center;
	gap: 2px;
	list-style: none;
	margin: 0;
	padding: 0;
}

.isa-nav li,
.isa-nav li + li {
	margin: 0;
}

.isa-nav a {
	display: inline-flex;
	align-items: center;
	min-height: 40px;
	padding: 0 var(--space-3);
	border-radius: var(--radius-sm);
	color: var(--ink-soft);
	text-decoration: none;
	font-size: var(--text-base);
	font-weight: 520;
	white-space: nowrap;
}

.isa-nav a:hover,
.isa-nav a[aria-current="page"] {
	color: var(--ink);
	background: var(--surface-subtle);
}

@media (min-width: 1200px) {
	.isa-nav {
		display: block;
		margin-left: var(--space-3);
	}
}

.isa-header__actions {
	display: flex;
	align-items: center;
	justify-content: flex-end;
	gap: var(--space-2);
	flex: 1 1 auto;
	min-width: 0;
	margin-left: auto;
}

/* Device pill: shrinks and truncates instead of pushing buttons away. */
.isa-header .isa-device-pill {
	display: inline-flex;
	align-items: center;
	gap: 6px;
	min-width: 0;
	max-width: 100%;
	height: 40px;
	padding: 0 var(--space-3);
	border: 1px solid var(--line-strong);
	border-radius: var(--radius-pill);
	background: var(--surface);
	color: var(--ink);
	font-family: inherit;
	font-size: var(--text-sm);
	font-weight: 600;
	line-height: 1;
	cursor: pointer;
	flex: 0 1 auto;
}

.isa-header .isa-device-pill:hover {
	background: var(--surface-subtle);
}

.isa-device-pill__icon {
	flex: 0 0 auto;
	color: var(--muted);
}

.isa-device-pill.is-set .isa-device-pill__icon {
	color: var(--success);
}

.isa-device-pill__model {
	min-width: 0;
	overflow: hidden;
	text-overflow: ellipsis;
	white-space: nowrap;
}

.isa-device-pill__os {
	display: none;
	flex: 0 0 auto;
	padding-left: 6px;
	border-left: 1px solid var(--line-strong);
	color: var(--muted);
	font-weight: 500;
	white-space: nowrap;
}

@media (min-width: 600px) {
	.isa-device-pill__os {
		display: inline;
	}
}

@media (min-width: 1200px) {
	.isa-header .isa-device-pill {
		max-width: 260px;
	}
}

/* Square icon buttons, 44px tap targets on touch screens. */
.isa-icon-button {
	display: inline-grid;
	place-items: center;
	flex: 0 0 auto;
	width: 44px;
	height: 44px;
	padding: 0;
	border: 1px solid transparent;
	border-radius: var(--radius-sm);
	background: transparent;
	color: var(--ink-soft);
	text-decoration: none;
	cursor: pointer;
}

.isa-icon-button:hover {
	background: var(--surface-subtle);
	color: var(--ink);
}

@media (min-width: 1200px) and (hover: hover) {
	.isa-icon-button {
		width: 40px;
		height: 40px;
	}
}

.isa-header__theme {
	display: none;
}

@media (min-width: 600px) {
	.isa-header__theme {
		display: inline-grid;
	}
}

.isa-header__menu-close {
	display: none;
}

.isa-header__menu[aria-expanded="true"] .isa-header__menu-open {
	display: none;
}

.isa-header__menu[aria-expanded="true"] .isa-header__menu-close {
	display: block;
}

@media (min-width: 1200px) {
	.isa-header__menu {
		display: none;
	}
}

/* Menu panel for everything below the full navigation breakpoint. */
.isa-mobile-nav {
	border-top: 1px solid var(--line);
	background: var(--surface);
	max-height: calc(100vh - 60px);
	overflow-y: auto;
}

.isa-mobile-nav nav,
.isa-mobile-nav__tools {
	max-width: 1280px;
	margin: 0 auto;
	padding: var(--space-2) var(--space-4);
}

@media (min-width: 768px) {
	.isa-mobile-nav nav,
	.isa-mobile-nav__tools {
		padding-left: var(--space-6);
		padding-right: var(--space-6);
	}
}

.isa-mobile-nav ul {
	list-style: none;
	margin: 0;
	padding: 0;
}

.isa-mobile-nav li,
.isa-mobile-nav li + li {
	margin: 0;
}

.isa-mobile-nav a {
	display: flex;
	align-items: center;
	min-height: 48px;
	padding: 0 var(--space-3);
	border-radius: var(--radius-sm);
	color: var(--ink);
	text-decoration: none;
	font-size: var(--text-md);
	font-weight: 560;
}

.isa-mobile-nav a:hover,
.isa-mobile-nav a[aria-current="page"] {
	background: var(--surface-subtle);
}

.isa-mobile-nav__tools {
	display: flex;
	flex-wrap: wrap;
	gap: var(--space-2);
	padding-bottom: var(--space-4);
	border-top: 1px solid var(--line);
	padding-top: var(--space-3);
}

.isa-mobile-nav__tool {
	flex: 1 1 160px;
	min-height: 44px;
	padding: 0 var(--space-4);
	border: 1px solid var(--line-strong);
	border-radius: var(--radius-sm);
	background: var(--surface);
	color: var(--ink);
	font-family: inherit;
	font-size: var(--text-base);
	font-weight: 560;
	cursor: pointer;
}

.isa-mobile-nav__tool:hover {
	background: var(--surface-subtle);
}

@media (min-width: 1200px) {
	.isa-mobile-nav {
		display: none !important;
	}
}

/* ---------------------------------------------------------------- Footer */

.isa-footer {
	margin-top: var(--space-8);
	border-top: 1px solid var(--line);
	background: var(--surface);
	padding: var(--space-7) 0 var(--space-6);
}

.isa-footer__grid {
	display: grid;
	gap: var(--space-6);
	grid-template-columns: 1fr;
}

@media (min-width: 720px) {
	.isa-footer__grid {
		grid-template-columns: 1.4fr 1fr 1fr;
	}
}

.isa-footer h2 {
	font-size: var(--text-sm);
	text-transform: uppercase;
	letter-spacing: var(--tracking-wide);
	color: var(--muted);
	margin-bottom: var(--space-3);
}

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

.isa-footer a {
	color: var(--ink-soft);
	text-decoration: none;
	font-size: var(--text-base);
}

.isa-footer a:hover {
	color: var(--accent);
	text-decoration: underline;
}

.isa-footer__legal {
	margin-top: var(--space-6);
	padding-top: var(--space-5);
	border-top: 1px solid var(--line);
	color: var(--muted);
	font-size: var(--text-sm);
	line-height: var(--leading-relaxed);
}

.isa-footer__legal p {
	color: var(--muted);
	font-size: var(--text-sm);
	max-width: 78ch;
}

/* ---------------------------------------------------------- Breadcrumbs */

.isa-breadcrumbs {
	/* Only the top: the side padding comes from .isa-container. */
	padding-top: var(--space-4);
	font-size: var(--text-sm);
	color: var(--muted);
}

.isa-breadcrumbs ol {
	display: flex;
	flex-wrap: wrap;
	align-items: center;
	gap: var(--space-2);
	list-style: none;
	margin: 0;
	padding: 0;
}

.isa-breadcrumbs li {
	margin: 0;
	display: flex;
	align-items: center;
	gap: var(--space-2);
}

.isa-breadcrumbs li + li::before {
	content: "/";
	color: var(--line-strong);
}

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

.isa-breadcrumbs a:hover {
	color: var(--accent);
	text-decoration: underline;
}

.isa-breadcrumbs [aria-current="page"] {
	color: var(--ink-soft);
}