/* PSG — KNOWLEDGE CENTER ACS
 * Analytical & Chromatography Systems
 * Apple Editorial / Laboratory Literature
 * Header refinement: align with the restrained AP-01 Knowledge Center editorial style.
 */

.knowledge-article--acs {
	--knowledge-ink: #17191C;
	--knowledge-muted: #72777F;
	--knowledge-line: #E5E7EB;
	--knowledge-surface: #F8F9FA;
	--knowledge-accent: #0047FF;
	--knowledge-paper: #FFFFFF;
	width: 100%;
	color: var(--knowledge-ink);
	background: var(--knowledge-paper);
	font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Segoe UI", sans-serif;
	font-size: 16px;
	line-height: 1.8;
	-webkit-font-smoothing: antialiased;
}

.knowledge-article--acs *,
.knowledge-article--acs *::before,
.knowledge-article--acs *::after {
	box-sizing: border-box;
}

.knowledge-article--acs a {
	color: inherit;
	text-decoration: none;
}

.knowledge-article--acs a:focus-visible {
	outline: 2px solid var(--knowledge-accent);
	outline-offset: 4px;
}

.knowledge-article--acs p {
	margin: 0 0 1.15rem;
}

.knowledge-article--acs h1,
.knowledge-article--acs h2,
.knowledge-article--acs h3,
.knowledge-article--acs h4 {
	margin-top: 0;
	color: var(--knowledge-ink);
	font-weight: 550;
	letter-spacing: -0.035em;
	line-height: 1.3;
}

.knowledge-article--acs h3 {
	font-size: 1.25rem;
}

.knowledge-article--acs h4 {
	font-size: 0.96rem;
	letter-spacing: -0.015em;
}

/* HERO — editorial spacing and restrained title scale */

.knowledge-article--acs .knowledge-hero {
	position: relative;
	overflow: hidden;
	padding: clamp(4.5rem, 9vw, 7.5rem) 6vw clamp(3.5rem, 7vw, 5.5rem);
	border-bottom: 1px solid var(--knowledge-line);
	background: #FAFAFA;
}

.knowledge-article--acs .knowledge-hero__inner {
	width: min(100%, 1120px);
	margin: 0 auto;
}

.knowledge-article--acs .knowledge-hero__eyebrow {
	display: flex;
	flex-wrap: wrap;
	align-items: center;
	gap: 12px;
	margin-bottom: clamp(2rem, 4vw, 3rem);
	color: var(--knowledge-muted);
	font-size: 0.68rem;
	font-weight: 650;
	letter-spacing: 0.13em;
	line-height: 1.6;
	text-transform: uppercase;
}

.knowledge-article--acs .knowledge-hero__divider {
	flex: 0 0 22px;
	width: 22px;
	height: 1px;
	background: var(--knowledge-accent);
}

.knowledge-article--acs .knowledge-hero__category {
	margin-bottom: 0.85rem;
	color: var(--knowledge-accent);
	font-size: 0.75rem;
	font-weight: 600;
	letter-spacing: 0.045em;
	line-height: 1.6;
}

.knowledge-article--acs .knowledge-hero__title {
	max-width: 900px;
	margin-bottom: 1rem;
	font-size: clamp(2.65rem, 6vw, 5.4rem);
	font-weight: 550;
	letter-spacing: -0.065em;
	line-height: 1.02;
	overflow-wrap: anywhere;
}

.knowledge-article--acs .knowledge-hero__technical {
	max-width: 760px;
	margin-bottom: 1.25rem;
	color: var(--knowledge-muted);
	font-size: clamp(0.98rem, 1.8vw, 1.2rem);
	letter-spacing: -0.02em;
	line-height: 1.65;
}

.knowledge-article--acs .knowledge-hero__abstract {
	max-width: 740px;
	margin-top: 1.5rem;
	margin-bottom: 1.5rem;
	color: #525860;
	font-size: clamp(0.98rem, 1.35vw, 1.08rem);
	line-height: 1.9;
}

.knowledge-article--acs .knowledge-hero__keywords {
	display: flex;
	flex-wrap: wrap;
	gap: 8px;
	margin-top: 1.5rem;
}

.knowledge-article--acs .knowledge-hero__keywords span {
	padding: 5px 10px;
	border: 1px solid #E1E4E8;
	border-radius: 3px;
	color: #555B63;
	background: rgba(255, 255, 255, 0.7);
	font-size: 0.73rem;
	line-height: 1.6;
}

/* ARTICLE LAYOUT */

.knowledge-article--acs .knowledge-layout {
	display: grid;
	grid-template-columns: minmax(190px, 240px) minmax(0, 1fr);
	gap: clamp(2.5rem, 6vw, 7rem);
	width: min(88%, 1440px);
	margin: 0 auto;
	padding-top: clamp(4rem, 7vw, 7rem);
	padding-bottom: 7rem;
}

.knowledge-article--acs .knowledge-sidebar {
	min-width: 0;
}

.knowledge-article--acs .knowledge-sidebar__inner {
	position: sticky;
	top: 2rem;
}

.knowledge-article--acs .knowledge-sidebar__eyebrow {
	margin-bottom: 1.5rem;
	color: var(--knowledge-muted);
	font-size: 0.68rem;
	font-weight: 650;
	letter-spacing: 0.12em;
}

.knowledge-article--acs .knowledge-toc {
	display: grid;
	gap: 3px;
	padding-left: 12px;
	border-left: 1px solid var(--knowledge-line);
}

.knowledge-article--acs .knowledge-toc a {
	padding: 7px 0 7px 12px;
	margin-left: -13px;
	border-left: 2px solid transparent;
	color: var(--knowledge-muted);
	font-size: 0.83rem;
	line-height: 1.55;
	transition: color 180ms ease, border-color 180ms ease;
}

.knowledge-article--acs .knowledge-toc a:hover {
	border-left-color: var(--knowledge-accent);
	color: var(--knowledge-accent);
}

.knowledge-article--acs .knowledge-content {
	min-width: 0;
}

/* ARTICLE SECTIONS */

.knowledge-article--acs .knowledge-section {
	padding-bottom: clamp(3.5rem, 7vw, 6rem);
	margin-bottom: clamp(3.5rem, 7vw, 6rem);
	border-bottom: 1px solid var(--knowledge-line);
	scroll-margin-top: 2rem;
}

.knowledge-article--acs .knowledge-section:last-child {
	margin-bottom: 0;
}

.knowledge-article--acs .knowledge-section__index {
	display: inline-block;
	margin-bottom: 1.1rem;
	color: var(--knowledge-accent);
	font-size: 0.72rem;
	font-weight: 650;
	letter-spacing: 0.1em;
}

.knowledge-article--acs .knowledge-section__title {
	max-width: 850px;
	margin-bottom: 1.5rem;
	font-size: clamp(1.9rem, 3.6vw, 3.1rem);
	letter-spacing: -0.06em;
	line-height: 1.12;
}

.knowledge-article--acs .knowledge-section__lead {
	max-width: 760px;
	margin-bottom: 2rem;
	color: var(--knowledge-muted);
	font-size: 1rem;
	line-height: 1.85;
}

.knowledge-article--acs .knowledge-section__body {
	max-width: 850px;
	color: #454B53;
	line-height: 1.95;
}

.knowledge-article--acs .knowledge-section__body > p:last-child {
	margin-bottom: 0;
}

/* LISTS AND DATA */

.knowledge-article--acs .knowledge-objectives,
.knowledge-article--acs .knowledge-limitations,
.knowledge-article--acs .knowledge-data-list {
	padding-left: 1.3rem;
	margin: 1.5rem 0 0;
	color: #454B53;
}

.knowledge-article--acs .knowledge-objectives li,
.knowledge-article--acs .knowledge-limitations li,
.knowledge-article--acs .knowledge-data-list > li {
	padding-left: 0.4rem;
	margin-bottom: 0.85rem;
}

.knowledge-article--acs .knowledge-objectives li::marker,
.knowledge-article--acs .knowledge-limitations li::marker,
.knowledge-article--acs .knowledge-data-list > li::marker {
	color: var(--knowledge-accent);
}

.knowledge-article--acs .knowledge-data-number {
	display: inline-block;
	margin-right: 0.5rem;
	color: var(--knowledge-accent);
	font-size: 0.8rem;
	font-weight: 650;
}

.knowledge-article--acs .knowledge-data-list strong {
	display: inline-block;
	margin-bottom: 0.3rem;
	color: var(--knowledge-ink);
	font-weight: 600;
}

.knowledge-article--acs .knowledge-data-list p {
	margin-top: 0.3rem;
	margin-bottom: 0.6rem;
}

.knowledge-article--acs .knowledge-data-list--nested {
	margin-top: 0.8rem;
	margin-bottom: 1rem;
	font-size: 0.94rem;
}

.knowledge-article--acs .knowledge-subsection {
	padding-top: 1rem;
	margin-top: 1.2rem;
	border-top: 1px solid var(--knowledge-line);
}

.knowledge-article--acs .knowledge-subsection h3 {
	margin-bottom: 0.8rem;
	font-size: 1rem;
	letter-spacing: -0.02em;
}

/* LEARNING CARDS */

.knowledge-article--acs .knowledge-learning-grid {
	display: grid;
	grid-template-columns: repeat(2, minmax(0, 1fr));
	gap: 16px;
	margin-top: 2.5rem;
}

.knowledge-article--acs .knowledge-learning-card {
	min-width: 0;
	padding: clamp(1.25rem, 2.5vw, 2rem);
	border: 1px solid var(--knowledge-line);
	border-radius: 4px;
	background: #FFFFFF;
	transition: border-color 180ms ease, transform 180ms ease;
	scroll-margin-top: 2rem;
}

.knowledge-article--acs .knowledge-learning-card:hover {
	border-color: #B8C6F0;
}

.knowledge-article--acs .knowledge-learning-card__top {
	display: flex;
	align-items: center;
	justify-content: space-between;
	gap: 12px;
	margin-bottom: 1.7rem;
}

.knowledge-article--acs .knowledge-learning-card__number {
	color: var(--knowledge-accent);
	font-size: 0.8rem;
	font-weight: 650;
	letter-spacing: 0.08em;
}

.knowledge-article--acs .knowledge-learning-card__slug {
	color: var(--knowledge-muted);
	font-size: 0.66rem;
	text-align: right;
	text-transform: uppercase;
	letter-spacing: 0.07em;
}

.knowledge-article--acs .knowledge-learning-card h3 {
	margin-bottom: 1rem;
	font-size: clamp(1.15rem, 2vw, 1.5rem);
}

.knowledge-article--acs .knowledge-learning-card > p {
	color: #565C64;
	font-size: 0.94rem;
	line-height: 1.85;
}

.knowledge-article--acs .knowledge-learning-card__details {
	padding-top: 1.2rem;
	margin-top: 1.5rem;
	border-top: 1px solid var(--knowledge-line);
}

.knowledge-article--acs .knowledge-learning-card__details h4 {
	margin-bottom: 0.8rem;
}

.knowledge-article--acs .knowledge-learning-card__details .knowledge-data-list {
	font-size: 0.88rem;
}

/* WORKFLOW */

.knowledge-article--acs .knowledge-workflow {
	position: relative;
	margin-top: 2.5rem;
}

.knowledge-article--acs .knowledge-workflow__item {
	display: grid;
	grid-template-columns: 54px minmax(0, 1fr);
	gap: clamp(1rem, 3vw, 2.5rem);
	padding: 2rem 0;
	border-top: 1px solid var(--knowledge-line);
}

.knowledge-article--acs .knowledge-workflow__item:last-child {
	border-bottom: 1px solid var(--knowledge-line);
}

.knowledge-article--acs .knowledge-workflow__number {
	display: flex;
	align-items: flex-start;
	justify-content: center;
	padding-top: 4px;
	color: var(--knowledge-accent);
	font-size: 0.8rem;
	font-weight: 650;
	letter-spacing: 0.06em;
}

.knowledge-article--acs .knowledge-workflow__content {
	min-width: 0;
}

.knowledge-article--acs .knowledge-workflow__technical {
	margin-bottom: 0.6rem;
	color: var(--knowledge-muted);
	font-size: 0.72rem;
	font-weight: 600;
	letter-spacing: 0.075em;
	text-transform: uppercase;
	overflow-wrap: anywhere;
}

.knowledge-article--acs .knowledge-workflow__content h3 {
	margin-bottom: 0.9rem;
	font-size: clamp(1.2rem, 2.2vw, 1.65rem);
}

.knowledge-article--acs .knowledge-workflow__content > p:not(.knowledge-workflow__technical) {
	color: #555B63;
	line-height: 1.9;
}

.knowledge-article--acs .knowledge-workflow__details {
	margin-top: 1.5rem;
}

.knowledge-article--acs .knowledge-workflow__details h4 {
	margin-bottom: 0.7rem;
}

.knowledge-article--acs .knowledge-workflow__details .knowledge-data-list {
	font-size: 0.92rem;
}

/* NOTES */

.knowledge-article--acs .knowledge-note {
	padding: 1.2rem 1.35rem;
	margin-top: 1.2rem;
	border-left: 2px solid var(--knowledge-accent);
	background: var(--knowledge-surface);
}

.knowledge-article--acs .knowledge-note strong {
	display: block;
	margin-bottom: 0.5rem;
	font-size: 0.86rem;
}

.knowledge-article--acs .knowledge-note p {
	margin-bottom: 0;
	color: #555B63;
	font-size: 0.92rem;
	line-height: 1.8;
}

/* SCIENTIFIC PRINCIPLES */

.knowledge-article--acs .knowledge-principles {
	display: grid;
	grid-template-columns: repeat(2, minmax(0, 1fr));
	gap: 0 2rem;
	margin-top: 2rem;
}

.knowledge-article--acs .knowledge-principle {
	padding: 1.7rem 0;
	border-top: 1px solid var(--knowledge-line);
}

.knowledge-article--acs .knowledge-principle h3 {
	margin-bottom: 0.75rem;
	font-size: 1.13rem;
}

.knowledge-article--acs .knowledge-principle p {
	margin-bottom: 0;
	color: #555B63;
	font-size: 0.94rem;
	line-height: 1.9;
}

/* TRANSITION */

.knowledge-article--acs .knowledge-section--transition {
	padding: clamp(1.5rem, 4vw, 3rem);
	border: 1px solid var(--knowledge-line);
	background: #FAFAFA;
}

/* REFERENCES */

.knowledge-article--acs .knowledge-references {
	display: grid;
	grid-template-columns: repeat(2, minmax(0, 1fr));
	gap: 14px;
	margin-top: 2rem;
}

.knowledge-article--acs .knowledge-reference {
	display: flex;
	flex-direction: column;
	align-items: flex-start;
	min-width: 0;
	padding: clamp(1.25rem, 2.5vw, 1.8rem);
	border: 1px solid var(--knowledge-line);
	border-radius: 4px;
	background: #FFFFFF;
}

.knowledge-article--acs .knowledge-reference__type {
	display: inline-block;
	margin-bottom: 1.1rem;
	color: var(--knowledge-accent);
	font-size: 0.68rem;
	font-weight: 650;
	letter-spacing: 0.07em;
	text-transform: uppercase;
}

.knowledge-article--acs .knowledge-reference h3 {
	margin-bottom: 0.6rem;
	font-size: 1.12rem;
	line-height: 1.5;
	overflow-wrap: anywhere;
}

.knowledge-article--acs .knowledge-reference__organization {
	color: var(--knowledge-muted);
	font-size: 0.84rem;
	line-height: 1.7;
}

.knowledge-article--acs .knowledge-reference__scope {
	width: 100%;
	margin-bottom: 1.2rem;
	font-size: 0.85rem;
}

.knowledge-article--acs .knowledge-reference__scope .knowledge-data-list {
	margin-top: 0.5rem;
}

.knowledge-article--acs .knowledge-reference > a {
	display: inline-flex;
	align-items: center;
	gap: 8px;
	padding-top: 0.8rem;
	margin-top: auto;
	color: var(--knowledge-accent);
	font-size: 0.84rem;
	font-weight: 600;
	line-height: 1.6;
}

.knowledge-article--acs .knowledge-reference > a:hover {
	text-decoration: underline;
	text-underline-offset: 4px;
}

.knowledge-article--acs .knowledge-reference__note {
	margin-top: auto;
	color: var(--knowledge-muted);
	font-size: 0.8rem;
}

/* EDITORIAL NOTES */

.knowledge-article--acs .knowledge-editorial {
	padding: clamp(1.5rem, 4vw, 3rem);
	border: 1px solid var(--knowledge-line);
	background: var(--knowledge-surface);
}

.knowledge-article--acs .knowledge-editorial h2 {
	margin-bottom: 1rem;
	font-size: 1.5rem;
}

.knowledge-article--acs .knowledge-editorial > p {
	color: #555B63;
	font-size: 0.94rem;
}

.knowledge-article--acs .knowledge-editorial .knowledge-data-list {
	font-size: 0.9rem;
}

.knowledge-article--acs .knowledge-editorial__status {
	padding-top: 1.3rem;
	margin-top: 1.5rem;
	border-top: 1px solid var(--knowledge-line);
}

.knowledge-article--acs .knowledge-editorial__status span {
	display: block;
	margin-bottom: 0.4rem;
	color: var(--knowledge-muted);
	font-size: 0.7rem;
	font-weight: 650;
	letter-spacing: 0.08em;
	text-transform: uppercase;
}

.knowledge-article--acs .knowledge-editorial__status p {
	margin-bottom: 0;
	font-size: 0.9rem;
}

.knowledge-article--acs .knowledge-editorial .knowledge-editorial__date {
	margin-top: 1.2rem;
	margin-bottom: 0;
	color: var(--knowledge-muted);
	font-size: 0.8rem;
}

/* RESPONSIVE */

@media (min-width: 1600px) {
	.knowledge-article--acs .knowledge-layout {
		width: min(88%, 1500px);
	}
}

@media (max-width: 1000px) {
	.knowledge-article--acs .knowledge-layout {
		grid-template-columns: 1fr;
		gap: 2.5rem;
		width: min(92%, 850px);
		padding-top: 3.5rem;
	}

	.knowledge-article--acs .knowledge-sidebar__inner {
		position: static;
	}

	.knowledge-article--acs .knowledge-toc {
		grid-template-columns: repeat(2, minmax(0, 1fr));
		gap: 4px 1.2rem;
	}

	.knowledge-article--acs .knowledge-learning-grid,
	.knowledge-article--acs .knowledge-principles,
	.knowledge-article--acs .knowledge-references {
		grid-template-columns: repeat(2, minmax(0, 1fr));
	}
}

@media (max-width: 640px) {
	.knowledge-article--acs {
		font-size: 15px;
	}

	.knowledge-article--acs .knowledge-hero {
		padding: 4rem 6vw 3.25rem;
	}

	.knowledge-article--acs .knowledge-hero__eyebrow {
		gap: 8px;
		margin-bottom: 2rem;
		font-size: 0.62rem;
	}

	.knowledge-article--acs .knowledge-hero__title {
		font-size: clamp(2.45rem, 11vw, 3.8rem);
		letter-spacing: -0.06em;
		line-height: 1.04;
	}

	.knowledge-article--acs .knowledge-hero__abstract {
		margin-top: 1.25rem;
		font-size: 0.96rem;
	}

	.knowledge-article--acs .knowledge-layout {
		width: 88%;
		padding-top: 3rem;
		padding-bottom: 4rem;
	}

	.knowledge-article--acs .knowledge-toc {
		grid-template-columns: 1fr;
	}

	.knowledge-article--acs .knowledge-section {
		padding-bottom: 3.5rem;
		margin-bottom: 3.5rem;
	}

	.knowledge-article--acs .knowledge-section__title {
		font-size: 2rem;
	}

	.knowledge-article--acs .knowledge-learning-grid,
	.knowledge-article--acs .knowledge-principles,
	.knowledge-article--acs .knowledge-references {
		grid-template-columns: 1fr;
	}

	.knowledge-article--acs .knowledge-learning-card {
		padding: 1.4rem;
	}

	.knowledge-article--acs .knowledge-workflow__item {
		grid-template-columns: 34px minmax(0, 1fr);
		gap: 12px;
		padding: 1.5rem 0;
	}

	.knowledge-article--acs .knowledge-workflow__number {
		justify-content: flex-start;
	}

	.knowledge-article--acs .knowledge-section--transition,
	.knowledge-article--acs .knowledge-editorial {
		padding: 1.4rem;
	}

	.knowledge-article--acs .knowledge-reference {
		padding: 1.4rem;
	}
}

@media (prefers-reduced-motion: reduce) {
	.knowledge-article--acs *,
	.knowledge-article--acs *::before,
	.knowledge-article--acs *::after {
		scroll-behavior: auto !important;
		transition: none !important;
	}
}