/* ─── Case Study Hero ────────────────────────────── */
.cs-hero {
	height: 100vh;
	max-height: 1082px;
	min-height: 600px;
	position: relative;
	display: flex;
	flex-direction: column;
	justify-content: center;
	align-items: center;
	overflow: hidden;
	background-color: #000;
}

.cs-hero__bg {
	position: absolute;
	inset: 0;
	z-index: 1;
}

.cs-hero__bg img {
	width: 100%;
	height: 100%;
	object-fit: cover;
}

.cs-hero__overlay {
	position: absolute;
	inset: 0;
	z-index: 2;
	background: rgba(0, 0, 0, 0.57);
}

.cs-hero__content {
	position: relative;
	z-index: 3;
	text-align: center;
	max-width: 1225px;
	padding: 0 var(--section-padding);
	display: flex;
	flex-direction: column;
	gap: 20px;
	align-items: center;
}

.cs-hero__title {
	font-size: 64px;
	font-weight: var(--font-weight-regular);
	color: var(--text-white);
	line-height: 1.1;
}

.cs-hero__client {
	font-size: 40px;
	font-weight: var(--font-weight-regular);
	color: rgba(172, 172, 172, 0.79);
}

/* ─── Sticky Section Nav ────────────────────────── */
.cs-nav {
	position: sticky;
	top: 0;
	z-index: 50;
	padding: 40px var(--section-padding);
	display: flex;
	justify-content: center;
}

.cs-nav__bar {
	display: inline-flex;
	gap: 70px;
	align-items: center;
	padding: 14px 50px;
	background: rgba(232, 232, 232, 0.5);
	backdrop-filter: blur(10px);
	-webkit-backdrop-filter: blur(10px);
	border-radius: 5px;
	box-shadow: 0 2px 20px rgba(0, 0, 0, 0.08);
	max-width: 100%;
}

.cs-nav__link {
	font-size: 20px;
	font-weight: var(--font-weight-light);
	color: #1b1b1b;
	white-space: nowrap;
	position: relative;
	transition: color 0.3s ease;
}

.cs-nav__link::after {
	content: '';
	position: absolute;
	bottom: -4px;
	left: 0;
	width: 0;
	height: 2px;
	background: var(--primary-red);
	transition: width 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

.cs-nav__link:hover {
	color: var(--primary-red);
}

.cs-nav__link.is-active {
	color: var(--primary-red);
}

.cs-nav__link.is-active::after {
	width: 100%;
}

/* ─── Overview Section ──────────────────────────── */
.cs-overview {
	padding: 50px var(--section-padding);
	display: flex;
	gap: clamp(60px, 12vw, 315px);
}

.cs-overview__info {
	flex: 1 1 0;
	max-width: 742px;
	display: flex;
	flex-direction: column;
	gap: 40px;
}

.cs-overview__meta {
	display: flex;
	flex-direction: column;
	gap: 24px;
}

.cs-overview__meta-item {
	display: flex;
	flex-direction: column;
	gap: 4px;
}

.cs-overview__meta-label {
	font-size: 20px;
	font-weight: var(--font-weight-regular);
	color: var(--text-gray);
}

.cs-overview__meta-value {
	font-size: 24px;
	font-weight: var(--font-weight-regular);
	color: var(--text-dark);
}

.cs-overview__links {
	display: flex;
	gap: 30px;
	align-items: center;
}

.cs-overview__link--visit {
	font-size: 20px;
	font-weight: var(--font-weight-regular);
	color: var(--primary-red);
	border-bottom: 2px solid var(--primary-red);
	padding-bottom: 4px;
	transition: opacity 0.2s;
}

.cs-overview__link--visit:hover {
	opacity: 0.7;
}

.cs-overview__link--share {
	font-size: 20px;
	font-weight: var(--font-weight-regular);
	color: var(--text-gray);
	border-bottom: 2px solid var(--text-gray);
	padding-bottom: 4px;
	transition: opacity 0.2s;
	cursor: pointer;
}

.cs-overview__link--share:hover {
	opacity: 0.7;
}

.cs-overview__services {
	display: flex;
	flex-direction: column;
	gap: 0;
}

.cs-overview__services-title {
	font-size: 20px;
	font-weight: var(--font-weight-regular);
	color: var(--text-gray);
	margin-bottom: 12px;
}

.cs-overview__services-list {
	font-size: 24px;
	font-weight: var(--font-weight-regular);
	color: var(--text-dark);
	line-height: 1.6;
}

.cs-overview__text {
	flex: 1;
	max-width: 630px;
}

.cs-overview__text p {
	font-size: 24px;
	font-weight: var(--font-weight-regular);
	color: #878787;
	line-height: 1.5;
}

/* ─── Content Section (shared for Problem, Goals, Approach, Solution) ── */
.cs-section {
	padding: clamp(60px, 8vw, 100px) var(--section-padding);
}

.cs-section__heading {
	font-size: 32px;
	font-weight: var(--font-weight-regular);
	color: var(--primary-red);
	max-width: 1146px;
	margin-bottom: 24px;
}

.cs-section__text {
	font-size: 24px;
	font-weight: var(--font-weight-regular);
	color: var(--text-dark);
	line-height: 1.5;
	margin-bottom: 60px;
}

.cs-section__text--goals {
	color: var(--text-dark);
}

/* ─── Image Grids ────────────────────────────────── */

/* Problem/Solution layout: 1 large + 2 small stacked */
.cs-images-grid--problem {
	display: grid;
	grid-template-columns: 1139fr 555fr;
	grid-template-rows: 1fr 1fr;
	gap: 20px;
}

.cs-images-grid--problem .cs-image:first-child {
	grid-row: 1 / -1;
	aspect-ratio: 1139 / 640;
}

.cs-images-grid--problem .cs-image:not(:first-child) {
	aspect-ratio: 555 / 310;
}

.cs-images-grid--problem .cs-image img,
.cs-images-grid--problem .cs-image-placeholder {
	width: 100%;
	height: 100%;
	object-fit: cover;
	border-radius: var(--radius);
}

/* Goals layout: 2 side-by-side */
.cs-images-grid--goals {
	display: grid;
	grid-template-columns: 1fr 1fr;
	gap: 20px;
}

.cs-images-grid--goals .cs-image {
	aspect-ratio: 846 / 473;
}

.cs-images-grid--goals .cs-image img,
.cs-images-grid--goals .cs-image-placeholder {
	width: 100%;
	height: 100%;
	object-fit: cover;
	border-radius: var(--radius);
}

/* Approach layout: 2 small stacked left + 1 large right */
.cs-images-grid--approach {
	display: grid;
	grid-template-columns: 557fr 1141fr;
	grid-template-rows: 1fr 1fr;
	gap: 18px 26px;
}

.cs-images-grid--approach .cs-image:last-child {
	grid-row: 1 / -1;
	grid-column: 2;
	aspect-ratio: 1141 / 642;
}

.cs-images-grid--approach .cs-image:not(:last-child) {
	aspect-ratio: 557 / 312;
}

.cs-images-grid--approach .cs-image img,
.cs-images-grid--approach .cs-image-placeholder {
	width: 100%;
	height: 100%;
	object-fit: cover;
	border-radius: var(--radius);
}

/* Shared image placeholder */
.cs-image-placeholder {
	background: var(--bg-light);
	border-radius: var(--radius);
}

/* ─── Goals Section Extra Padding ────────────────── */
.cs-section--goals {
	padding-bottom: 300px;
}

.cs-section--approach {
	padding-bottom: 300px;
}

/* ─── Results Section ────────────────────────────── */
.cs-results {
	padding: clamp(60px, 8vw, 100px) var(--section-padding);
}

.cs-results__title {
	font-size: 36px;
	font-weight: var(--font-weight-regular);
	color: var(--text-dark);
	margin-bottom: 60px;
}

.cs-results__grid {
	display: flex;
	flex-wrap: wrap;
	gap: clamp(40px, 9vw, 170px);
}

.cs-result {
	display: flex;
	flex-direction: column;
	gap: 8px;
	border-left: 5px solid var(--primary-red);
	padding-left: 24px;
}

.cs-result__value {
	font-size: 64px;
	font-weight: var(--font-weight-bold);
	color: var(--text-dark);
	line-height: 1;
}

.cs-result__label {
	font-size: 40px;
	font-weight: var(--font-weight-regular);
	color: #818181;
	line-height: 1.2;
}

/* ─── Testimonial Section ────────────────────────── */
.cs-testimonial {
	position: relative;
	min-height: 920px;
	overflow: clip;
	display: flex;
	align-items: flex-start;
	justify-content: center;
}

.cs-testimonial__watermark {
	position: absolute;
	top: 0;
	left: 50%;
	transform: translateX(-50%);
	font-size: clamp(72px, 18vw, 250px);
	font-weight: var(--font-weight-bold);
	text-transform: uppercase;
	white-space: nowrap;
	line-height: 1;
	background: linear-gradient(180deg, transparent 0%, rgba(255, 255, 255, 1) 100%);
	-webkit-background-clip: text;
	-webkit-text-fill-color: transparent;
	background-clip: text;
	opacity: 0.9;
	pointer-events: none;
	z-index: 1;
}

.cs-testimonial__card {
	position: absolute;
	top: 380px;
	left: var(--section-padding);
	right: var(--section-padding);
	background: var(--primary-red);
	border-radius: var(--radius);
	padding: 60px;
	z-index: 2;
	display: flex;
	flex-direction: column;
	gap: 40px;
}

.cs-testimonial__quote {
	font-size: 40px;
	font-weight: var(--font-weight-light);
	color: var(--text-white);
	line-height: 1.2;
	max-width: 1124px;
}

.cs-testimonial__author {
	font-size: 32px;
	font-weight: var(--font-weight-regular);
	color: var(--text-white);
	opacity: 0.6;
	line-height: 1.3;
}

/* ─── Related Projects Section ───────────────────── */
.cs-related {
	padding: clamp(60px, 8vw, 100px) var(--section-padding) clamp(80px, 15vw, 300px);
}

.cs-related__title {
	font-size: 36px;
	font-weight: var(--font-weight-regular);
	color: var(--text-dark);
	margin-bottom: 60px;
}

.cs-related__grid {
	display: grid;
	grid-template-columns: repeat(3, 1fr);
	gap: clamp(24px, 3vw, 50px);
}

.cs-related-card {
	display: flex;
	flex-direction: column;
	gap: 16px;
	transition: transform 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

.cs-related-card:hover {
	transform: translateY(-4px);
}

.cs-related-card__image {
	border-radius: var(--radius);
	overflow: hidden;
	aspect-ratio: 516 / 290;
}

.cs-related-card__image img {
	transition: transform 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

.cs-related-card:hover .cs-related-card__image img {
	transform: scale(1.03);
}

.cs-related-card__image img {
	width: 100%;
	height: 100%;
	object-fit: cover;
}

.cs-related-card__image-placeholder {
	width: 100%;
	height: 100%;
	background: var(--bg-light);
}

.cs-related-card__title {
	font-size: 36px;
	font-weight: var(--font-weight-light);
	color: var(--text-dark);
	line-height: 1.2;
}

.cs-related-card__desc {
	font-size: 16px;
	font-weight: var(--font-weight-regular);
	color: var(--text-body-gray);
	line-height: 1.4;
}

.cs-related-card__link {
	display: inline-flex;
	font-size: 20px;
	font-weight: var(--font-weight-regular);
	color: var(--primary-red);
	border-bottom: 2px solid var(--primary-red);
	padding-bottom: 4px;
	transition: opacity 0.2s;
	align-self: flex-start;
}

.cs-related-card__link:hover {
	opacity: 0.7;
}

/* ─── Back to Top Button ─────────────────────────── */
.cs-back-to-top {
	position: fixed;
	bottom: 40px;
	right: 40px;
	z-index: 60;
	display: flex;
	align-items: center;
	gap: 8px;
	padding: 12px 20px;
	background: rgba(232, 232, 232, 0.5);
	backdrop-filter: blur(10px);
	-webkit-backdrop-filter: blur(10px);
	border-radius: 5px;
	box-shadow: 0 2px 20px rgba(0, 0, 0, 0.08);
	font-size: 16px;
	font-weight: var(--font-weight-regular);
	color: #1b1b1b;
	cursor: pointer;
	opacity: 0;
	visibility: hidden;
	transform: translateY(10px);
	transition: opacity 0.4s ease, visibility 0.4s ease, transform 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

.cs-back-to-top.is-visible {
	opacity: 1;
	visibility: visible;
	transform: translateY(0);
}

.cs-back-to-top:hover {
	background: rgba(232, 232, 232, 0.7);
}

.cs-back-to-top__icon {
	width: 16px;
	height: 16px;
	flex-shrink: 0;
}

/* ─── Responsive: 1440px ─────────────────────────── */
@media (max-width: 1440px) {
	.cs-hero__title {
		font-size: 58px;
	}

	.cs-hero__client {
		font-size: 36px;
	}

	.cs-nav {
		padding: 32px var(--section-padding);
	}

	.cs-nav__bar {
		gap: 48px;
		padding: 12px 36px;
	}

	.cs-overview {
		gap: clamp(60px, 10vw, 200px);
	}

	.cs-section--goals,
	.cs-section--approach {
		padding-bottom: clamp(180px, 22vw, 300px);
	}
}

/* ─── Responsive: 1200px ─────────────────────────── */
@media (max-width: 1200px) {
	.cs-hero__title {
		font-size: 52px;
	}

	.cs-hero__client {
		font-size: 32px;
	}

	.cs-nav {
		padding: 28px var(--section-padding);
	}

	.cs-nav__bar {
		gap: 36px;
		padding: 12px 28px;
	}

	.cs-nav__link {
		font-size: 18px;
	}

	.cs-overview {
		gap: 60px;
	}

	.cs-overview__info {
		max-width: none;
	}

	.cs-overview__text {
		max-width: none;
	}

	.cs-overview__text p {
		font-size: 22px;
	}

	.cs-section__text {
		font-size: 22px;
	}

	.cs-result__value {
		font-size: 48px;
	}

	.cs-result__label {
		font-size: 28px;
	}

	.cs-testimonial__card {
		padding: 48px;
	}

	.cs-testimonial__quote {
		font-size: 32px;
	}

	.cs-testimonial__author {
		font-size: 26px;
	}

	.cs-section--goals,
	.cs-section--approach {
		padding-bottom: clamp(140px, 18vw, 220px);
	}

	.cs-related-card__title {
		font-size: 28px;
	}
}

/* ─── Responsive: 1024px ─────────────────────────── */
@media (max-width: 1024px) {
	.cs-hero {
		height: 80vh;
		min-height: 520px;
	}

	.cs-hero__title {
		font-size: 44px;
	}

	.cs-hero__client {
		font-size: 28px;
	}

	.cs-nav {
		padding: 20px var(--section-padding);
		overflow-x: auto;
		-webkit-overflow-scrolling: touch;
		justify-content: flex-start;
	}

	.cs-nav__bar {
		gap: 28px;
		padding: 10px 24px;
		flex-shrink: 0;
	}

	.cs-nav__link {
		font-size: 16px;
	}

	.cs-overview {
		flex-direction: column;
		gap: 40px;
	}

	.cs-overview__info {
		max-width: 100%;
	}

	.cs-overview__text {
		max-width: 100%;
	}

	.cs-images-grid--problem,
	.cs-images-grid--approach {
		grid-template-columns: 1fr;
		grid-template-rows: auto;
		gap: 16px;
	}

	.cs-images-grid--problem .cs-image:first-child,
	.cs-images-grid--approach .cs-image:last-child {
		grid-row: auto;
		grid-column: auto;
	}

	.cs-images-grid--problem .cs-image,
	.cs-images-grid--approach .cs-image,
	.cs-images-grid--problem .cs-image:first-child,
	.cs-images-grid--approach .cs-image:last-child,
	.cs-images-grid--problem .cs-image:not(:first-child),
	.cs-images-grid--approach .cs-image:not(:last-child) {
		aspect-ratio: 16 / 9;
	}

	.cs-results__grid {
		gap: 40px;
	}

	.cs-testimonial {
		min-height: 0;
		height: auto;
	}

	.cs-testimonial__card {
		position: relative;
		top: auto;
		left: auto;
		right: auto;
		margin: clamp(120px, 22vw, 280px) var(--section-padding) 60px;
		padding: 40px;
	}

	.cs-testimonial__quote {
		font-size: 28px;
	}

	.cs-testimonial__author {
		font-size: 24px;
	}

	.cs-related__grid {
		grid-template-columns: repeat(2, 1fr);
	}

	.cs-related-card__title {
		font-size: 26px;
	}

	.cs-section--goals,
	.cs-section--approach {
		padding-bottom: clamp(100px, 14vw, 160px);
	}
}

/* ─── Responsive: 768px ──────────────────────────── */
@media (max-width: 768px) {
	.cs-hero {
		height: auto;
		min-height: 70vh;
		max-height: none;
	}

	.cs-hero__title {
		font-size: 32px;
	}

	.cs-hero__client {
		font-size: 22px;
	}

	.cs-hero__content {
		gap: 12px;
	}

	.cs-nav {
		top: 0;
		padding: 16px var(--section-padding);
	}

	.cs-nav__bar {
		gap: 20px;
		padding: 10px 18px;
	}

	.cs-nav__link {
		font-size: 14px;
	}

	.cs-overview {
		padding: 40px var(--section-padding);
		gap: 32px;
	}

	.cs-overview__info {
		gap: 28px;
	}

	.cs-overview__meta-label,
	.cs-overview__services-title,
	.cs-overview__link--visit,
	.cs-overview__link--share {
		font-size: 16px;
	}

	.cs-overview__meta-value,
	.cs-overview__services-list {
		font-size: 18px;
	}

	.cs-overview__links {
		gap: 20px;
		flex-wrap: wrap;
	}

	.cs-overview__text p {
		font-size: 18px;
	}

	.cs-section__heading {
		font-size: 24px;
	}

	.cs-section__text {
		font-size: 18px;
		margin-bottom: 32px;
	}

	.cs-images-grid--goals {
		grid-template-columns: 1fr;
		gap: 16px;
	}

	.cs-results__title {
		font-size: 28px;
		margin-bottom: 32px;
	}

	.cs-results__grid {
		flex-direction: column;
		gap: 28px;
	}

	.cs-result {
		padding-left: 18px;
		border-left-width: 4px;
	}

	.cs-result__value {
		font-size: 40px;
	}

	.cs-result__label {
		font-size: 22px;
	}

	.cs-testimonial__card {
		margin-top: clamp(80px, 24vw, 160px);
		padding: 28px;
		gap: 24px;
	}

	.cs-testimonial__quote {
		font-size: 20px;
	}

	.cs-testimonial__author {
		font-size: 18px;
	}

	.cs-related__title {
		font-size: 28px;
		margin-bottom: 32px;
	}

	.cs-related__grid {
		grid-template-columns: 1fr;
		gap: 32px;
	}

	.cs-related-card__title {
		font-size: 24px;
	}

	.cs-related-card__desc {
		font-size: 15px;
	}

	.cs-related-card__link {
		font-size: 16px;
	}

	.cs-back-to-top {
		bottom: 20px;
		right: 20px;
		padding: 10px 16px;
		font-size: 14px;
	}
}

/* ─── Responsive: 480px ──────────────────────────── */
@media (max-width: 480px) {
	.cs-hero {
		min-height: 60vh;
	}

	.cs-hero__title {
		font-size: 28px;
	}

	.cs-hero__client {
		font-size: 18px;
	}

	.cs-nav__bar {
		gap: 16px;
		padding: 8px 14px;
	}

	.cs-nav__link {
		font-size: 13px;
	}

	.cs-section__heading {
		font-size: 22px;
	}

	.cs-section__text,
	.cs-overview__text p {
		font-size: 16px;
	}

	.cs-result__value {
		font-size: 36px;
	}

	.cs-result__label {
		font-size: 20px;
	}

	.cs-testimonial__card {
		padding: 22px;
	}

	.cs-testimonial__quote {
		font-size: 18px;
	}

	.cs-related-card__title {
		font-size: 22px;
	}
}

/* ─── Responsive: 1680px+ ────────────────────────── */
@media (min-width: 1680px) {
	.cs-hero__content {
		max-width: 1440px;
		gap: 28px;
	}
	.cs-hero__title {
		font-size: 76px;
	}
	.cs-hero__client {
		font-size: 46px;
	}
	.cs-nav {
		padding: 50px var(--section-padding);
	}
}

/* ─── Responsive: 1920px+ ────────────────────────── */
@media (min-width: 1920px) {
	.cs-hero__content {
		max-width: 1600px;
	}
	.cs-hero__title {
		font-size: 88px;
	}
	.cs-hero__client {
		font-size: 52px;
	}
	.cs-nav {
		padding: 50px var(--section-padding);
	}

	.cs-overview__text {
		max-width: 780px;
	}

	.cs-section__text,
	.cs-section__heading {
		max-width: 1200px;
	}

	.cs-testimonial__quote {
		max-width: 1300px;
	}
}

/* ─── Responsive: 2400px+ ────────────────────────── */
@media (min-width: 2400px) {
	.cs-hero__content {
		max-width: 1800px;
	}
	.cs-hero__title {
		font-size: 104px;
	}
	.cs-hero__client {
		font-size: 60px;
	}
	.cs-nav {
		padding: 50px var(--section-padding);
	}

	/* Cap content-bearing sections so layout doesn't sprawl on 2.5K+ displays */
	.cs-overview,
	.cs-section,
	.cs-results,
	.cs-related {
		max-width: var(--max-width);
		margin-inline: auto;
	}

	.cs-overview {
		gap: 200px;
	}

	.cs-overview__info {
		flex: 0 0 600px;
	}

	.cs-overview__text {
		flex: 1 1 auto;
		max-width: 1100px;
	}

	.cs-overview__text p {
		font-size: 28px;
	}

	.cs-section__text {
		max-width: 1400px;
	}

	.cs-section__heading {
		max-width: 1400px;
		font-size: 40px;
	}

	.cs-result__value {
		font-size: 80px;
	}

	.cs-result__label {
		font-size: 48px;
	}

	.cs-results__title,
	.cs-related__title {
		font-size: 48px;
	}

	/* Testimonial: cap card width so quote fills it, recenter */
	.cs-testimonial__card {
		left: 50%;
		right: auto;
		transform: translateX(-50%);
		width: min(calc(var(--max-width) - 2 * var(--section-padding)), 1600px);
		padding: 72px;
	}

	.cs-testimonial__quote {
		font-size: 48px;
		max-width: none;
	}

	.cs-testimonial__author {
		font-size: 36px;
	}

	.cs-related-card__title {
		font-size: 42px;
	}

	.cs-related-card__desc {
		font-size: 18px;
	}
}