/* ============================================================
   SARAH DENTON — PORTFOLIO
   Design System & Global Styles
   Colors use CSS custom properties — swap --color-accent to
   change the entire palette in one place.
   ============================================================ */

/* ── Imports ──────────────────────────────────────────────── */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600&display=swap');

/* ── Custom Properties ────────────────────────────────────── */
:root {
  /* Colors (neutral palette — finalize accent color later) */
  --color-bg:             #FFFFFF;
  --color-surface:        #F7F7F5;
  --color-surface-2:      #EFEFEC;
  --color-text-primary:   #1A1A1A;
  --color-text-secondary: #5A5A5A;
  --color-text-muted:     #9A9A9A;
  --color-border:         #E4E4E0;
  --color-accent:         #1A1A1A;      /* ← swap this to brand color */
  --color-accent-hover:   #3D3D3D;
  --color-accent-subtle:  #F0F0EE;

  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

  /* Type scale */
  --text-xs:   0.75rem;    /*  12px */
  --text-sm:   0.875rem;   /*  14px */
  --text-base: 1rem;       /*  16px */
  --text-lg:   1.125rem;   /*  18px */
  --text-xl:   1.25rem;    /*  20px */
  --text-2xl:  1.5rem;     /*  24px */
  --text-3xl:  1.875rem;   /*  30px */
  --text-4xl:  2.5rem;     /*  40px */
  --text-5xl:  3.25rem;    /*  52px */

  /* Weights */
  --fw-light:   300;
  --fw-regular: 400;
  --fw-medium:  500;
  --fw-semibold: 600;

  /* Line heights */
  --lh-tight:  1.2;
  --lh-snug:   1.4;
  --lh-normal: 1.6;
  --lh-relaxed: 1.75;

  /* Spacing */
  --space-1:  0.25rem;
  --space-2:  0.5rem;
  --space-3:  0.75rem;
  --space-4:  1rem;
  --space-5:  1.25rem;
  --space-6:  1.5rem;
  --space-8:  2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;
  --space-32: 8rem;

  /* Layout */
  --max-width:       1160px;
  --max-width-prose: 680px;
  --nav-height:      72px;

  /* Border radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
  --transition-slow: 400ms ease;

  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.07), 0 2px 6px rgba(0,0,0,0.04);
  --shadow-lg: 0 12px 32px rgba(0,0,0,0.08), 0 4px 12px rgba(0,0,0,0.04);
}

/* ── Reset & Base ─────────────────────────────────────────── */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  font-family: var(--font-sans);
  font-size: var(--text-base);
  font-weight: var(--fw-regular);
  line-height: var(--lh-relaxed);
  color: var(--color-text-primary);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

a {
  color: inherit;
  text-decoration: none;
}

ul, ol {
  list-style: none;
}

button {
  cursor: pointer;
  font-family: inherit;
  border: none;
  background: none;
}

/* ── Typography Utilities ─────────────────────────────────── */
.text-xs      { font-size: var(--text-xs); }
.text-sm      { font-size: var(--text-sm); }
.text-lg      { font-size: var(--text-lg); }
.text-xl      { font-size: var(--text-xl); }
.text-2xl     { font-size: var(--text-2xl); }
.text-3xl     { font-size: var(--text-3xl); }
.text-muted   { color: var(--color-text-muted); }
.text-secondary { color: var(--color-text-secondary); }
.fw-light     { font-weight: var(--fw-light); }
.fw-medium    { font-weight: var(--fw-medium); }
.fw-semibold  { font-weight: var(--fw-semibold); }

/* ── Layout Utilities ─────────────────────────────────────── */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin-inline: auto;
  padding-inline: var(--space-8);
}

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

.section {
  padding-block: var(--space-24);
}

.section--sm {
  padding-block: var(--space-16);
}

.section--lg {
  padding-block: var(--space-32);
}

.section-label {
  font-size: var(--text-xs);
  font-weight: var(--fw-medium);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: var(--space-10);
}

/* ── Navigation ───────────────────────────────────────────── */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--nav-height);
  background: rgba(255,255,255,0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition-base);
}

.nav.scrolled {
  border-bottom-color: var(--color-border);
}

.nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.nav__logo {
  font-size: var(--text-base);
  font-weight: var(--fw-medium);
  letter-spacing: -0.01em;
  color: var(--color-text-primary);
  transition: opacity var(--transition-fast);
}

.nav__logo:hover {
  opacity: 0.65;
}

.nav__links {
  display: flex;
  align-items: center;
  gap: var(--space-8);
}

.nav__link {
  font-size: var(--text-sm);
  font-weight: var(--fw-regular);
  color: var(--color-text-secondary);
  transition: color var(--transition-fast);
  position: relative;
}

.nav__link::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  right: 0;
  height: 1px;
  background: var(--color-text-primary);
  transform: scaleX(0);
  transition: transform var(--transition-base);
  transform-origin: left;
}

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

.nav__link:hover::after {
  transform: scaleX(1);
}

.nav__link.active {
  color: var(--color-text-primary);
}

.nav__cta {
  font-size: var(--text-sm);
  font-weight: var(--fw-medium);
  color: var(--color-bg);
  background: var(--color-accent);
  padding: var(--space-2) var(--space-5);
  border-radius: var(--radius-sm);
  transition: background var(--transition-fast), opacity var(--transition-fast);
}

.nav__cta:hover {
  opacity: 0.8;
}

/* Mobile nav */
.nav__hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: var(--space-2);
}

.nav__hamburger span {
  display: block;
  width: 22px;
  height: 1.5px;
  background: var(--color-text-primary);
  transition: transform var(--transition-base), opacity var(--transition-base);
}

.nav__hamburger.open span:nth-child(1) { transform: translateY(6.5px) rotate(45deg); }
.nav__hamburger.open span:nth-child(2) { opacity: 0; }
.nav__hamburger.open span:nth-child(3) { transform: translateY(-6.5px) rotate(-45deg); }

/* ── Buttons ──────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  font-weight: var(--fw-medium);
  border-radius: var(--radius-sm);
  padding: var(--space-3) var(--space-6);
  transition: all var(--transition-fast);
  cursor: pointer;
  letter-spacing: 0.01em;
}

.btn--primary {
  background: var(--color-accent);
  color: var(--color-bg);
  border: 1px solid var(--color-accent);
}

.btn--primary:hover {
  opacity: 0.82;
}

.btn--outline {
  background: transparent;
  color: var(--color-text-primary);
  border: 1px solid var(--color-border);
}

.btn--outline:hover {
  border-color: var(--color-text-secondary);
  background: var(--color-surface);
}

.btn--ghost {
  background: transparent;
  color: var(--color-text-secondary);
  border: 1px solid transparent;
  padding-inline: var(--space-2);
}

.btn--ghost:hover {
  color: var(--color-text-primary);
}

/* Arrow link */
.link-arrow {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  font-weight: var(--fw-medium);
  color: var(--color-text-primary);
  transition: gap var(--transition-fast);
}

.link-arrow:hover {
  gap: var(--space-3);
}

.link-arrow::after {
  content: '→';
  transition: transform var(--transition-fast);
}

/* ── Tags / Chips ─────────────────────────────────────────── */
.tag {
  display: inline-block;
  font-size: var(--text-xs);
  font-weight: var(--fw-medium);
  letter-spacing: 0.04em;
  color: var(--color-text-secondary);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 100px;
  padding: var(--space-1) var(--space-3);
}

.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

/* ── Image Placeholders ───────────────────────────────────── */
.img-placeholder {
  background: var(--color-surface);
  border: 1px dashed var(--color-border);
  border-radius: var(--radius-md);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  color: var(--color-text-muted);
  font-size: var(--text-xs);
  font-weight: var(--fw-medium);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  text-align: center;
  padding: var(--space-8);
  width: 100%;
}

.img-placeholder--hero {
  min-height: 400px;
}

.img-placeholder--wide {
  min-height: 320px;
}

.img-placeholder--card {
  min-height: 240px;
}

.img-placeholder--sm {
  min-height: 180px;
}

.img-placeholder__icon {
  font-size: 1.5rem;
  opacity: 0.4;
}

/* ── Divider ──────────────────────────────────────────────── */
.divider {
  border: none;
  border-top: 1px solid var(--color-border);
  margin-block: var(--space-16);
}

/* ── Hero (Homepage) ──────────────────────────────────────── */
.hero {
  padding-top: calc(var(--nav-height) + var(--space-24));
  padding-bottom: var(--space-24);
}

.hero__eyebrow {
  font-size: var(--text-xs);
  font-weight: var(--fw-medium);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: var(--space-6);
}

.hero__headline {
  font-size: clamp(var(--text-4xl), 5vw, var(--text-5xl));
  font-weight: var(--fw-light);
  line-height: var(--lh-tight);
  letter-spacing: -0.02em;
  color: var(--color-text-primary);
  max-width: 16ch;
  margin-bottom: var(--space-6);
}

.hero__headline em {
  font-style: italic;
}

.hero__sub {
  font-size: var(--text-lg);
  color: var(--color-text-secondary);
  line-height: var(--lh-relaxed);
  max-width: 52ch;
  margin-bottom: var(--space-10);
}

.hero__actions {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  flex-wrap: wrap;
}

/* ── Work Grid (Homepage) ─────────────────────────────────── */
.work-grid {
  display: grid;
  gap: var(--space-6);
}

/* First card full-width, next two side by side */
.work-grid__item:first-child {
  grid-column: 1 / -1;
}

@media (min-width: 768px) {
  .work-grid {
    grid-template-columns: 1fr 1fr;
  }
  .work-grid__item:first-child {
    grid-column: 1 / -1;
  }
}

/* ── Work Card ────────────────────────────────────────────── */
.work-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: box-shadow var(--transition-base), transform var(--transition-base);
  display: flex;
  flex-direction: column;
}

.work-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-3px);
}

.work-card__image {
  flex-shrink: 0;
  display: block;
  height: 280px;
  overflow: hidden;
}

.work-card__image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
  display: block;
}

.work-card__body {
  padding: var(--space-8);
  flex: 1;
  display: flex;
  flex-direction: column;
}

.work-card__meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-4);
}

.work-card__number {
  font-size: var(--text-xs);
  font-weight: var(--fw-medium);
  color: var(--color-text-muted);
  letter-spacing: 0.06em;
}

.work-card__title {
  font-size: var(--text-xl);
  font-weight: var(--fw-medium);
  line-height: var(--lh-snug);
  letter-spacing: -0.01em;
  margin-bottom: var(--space-3);
}

.work-card__desc {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  line-height: var(--lh-relaxed);
  flex: 1;
  margin-bottom: var(--space-6);
}

.work-card__footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-3);
}

/* ── Case Study Layout ────────────────────────────────────── */
.cs-hero {
  padding-top: calc(var(--nav-height) + var(--space-20));
  padding-bottom: var(--space-16);
  border-bottom: 1px solid var(--color-border);
}

.cs-hero__back {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin-bottom: var(--space-8);
  transition: color var(--transition-fast);
}

.cs-hero__back:hover {
  color: var(--color-text-primary);
}

.cs-hero__back::before {
  content: '←';
}

.cs-category {
  font-size: var(--text-xs);
  font-weight: var(--fw-medium);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: var(--space-4);
}

.cs-title {
  font-size: clamp(var(--text-3xl), 4vw, var(--text-5xl));
  font-weight: var(--fw-light);
  line-height: var(--lh-tight);
  letter-spacing: -0.02em;
  max-width: 20ch;
  margin-bottom: var(--space-6);
}

.cs-subtitle {
  font-size: var(--text-lg);
  color: var(--color-text-secondary);
  max-width: 58ch;
  line-height: var(--lh-relaxed);
  margin-bottom: var(--space-10);
}

/* Case study meta bar */
.cs-meta-bar {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: var(--space-6);
  padding: var(--space-8) 0;
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}

.cs-meta-item__label {
  font-size: var(--text-xs);
  font-weight: var(--fw-medium);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: var(--space-1);
}

.cs-meta-item__value {
  font-size: var(--text-sm);
  color: var(--color-text-primary);
  font-weight: var(--fw-medium);
}

/* Case study body */
.cs-body {
  display: grid;
  gap: var(--space-16);
}

@media (min-width: 900px) {
  .cs-body {
    grid-template-columns: 1fr 260px;
    gap: var(--space-16);
    align-items: start;
  }

  .cs-sidebar {
    position: sticky;
    top: calc(var(--nav-height) + var(--space-8));
  }
}

.cs-main {
  min-width: 0; /* Prevent grid column from overflowing due to scroll content */
}

.cs-main > * + * {
  margin-top: var(--space-12);
}

/* Headings within case study content */
.cs-main h2 {
  font-size: var(--text-2xl);
  font-weight: var(--fw-medium);
  letter-spacing: -0.01em;
  line-height: var(--lh-snug);
  margin-bottom: var(--space-4);
}

.cs-main h3 {
  font-size: var(--text-lg);
  font-weight: var(--fw-medium);
  margin-bottom: var(--space-3);
}

.cs-main p {
  font-size: var(--text-base);
  color: var(--color-text-secondary);
  line-height: var(--lh-relaxed);
  max-width: 68ch;
}

.cs-main p + p {
  margin-top: var(--space-4);
}

/* Pull quote */
.pull-quote {
  border-left: 2px solid var(--color-accent);
  padding-left: var(--space-6);
  margin-block: var(--space-8);
}

.pull-quote__text {
  font-size: var(--text-xl);
  font-weight: var(--fw-light);
  font-style: italic;
  line-height: var(--lh-snug);
  color: var(--color-text-primary);
  margin-bottom: var(--space-2);
}

.pull-quote__attribution {
  font-size: var(--text-xs);
  font-weight: var(--fw-medium);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-text-muted);
}

/* Process steps */
.process-steps {
  display: grid;
  gap: var(--space-6);
  counter-reset: step;
}

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

.process-step {
  counter-increment: step;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-6);
  position: relative;
}

.process-step__number {
  font-size: var(--text-xs);
  font-weight: var(--fw-semibold);
  letter-spacing: 0.08em;
  color: var(--color-text-muted);
  margin-bottom: var(--space-3);
}

.process-step__title {
  font-size: var(--text-base);
  font-weight: var(--fw-medium);
  margin-bottom: var(--space-2);
}

.process-step__body {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  line-height: var(--lh-relaxed);
}

/* Stat callouts */
.stats-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: var(--space-4);
  margin-block: var(--space-8);
}

.stat-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-6);
  text-align: center;
}

.stat-card__number {
  font-size: var(--text-4xl);
  font-weight: var(--fw-light);
  letter-spacing: -0.03em;
  line-height: 1;
  color: var(--color-text-primary);
  margin-bottom: var(--space-2);
}

.stat-card__label {
  font-size: var(--text-xs);
  font-weight: var(--fw-medium);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-text-muted);
}

/* Sidebar */
.cs-sidebar__block {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-6);
}

.cs-sidebar__block + .cs-sidebar__block {
  margin-top: var(--space-4);
}

.cs-sidebar__label {
  font-size: var(--text-xs);
  font-weight: var(--fw-medium);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: var(--space-4);
}

.cs-sidebar__list {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.cs-sidebar__list li {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
}

/* Content section block */
.content-block {
  padding: var(--space-8);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
}

.content-block p {
  max-width: none;
}

/* Findings list */
.findings-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  margin-top: var(--space-4);
}

.finding {
  display: flex;
  gap: var(--space-4);
  align-items: flex-start;
}

.finding__number {
  flex-shrink: 0;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--text-xs);
  font-weight: var(--fw-semibold);
  color: var(--color-text-muted);
}

.finding__text {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  line-height: var(--lh-relaxed);
  padding-top: 4px;
}

/* ── About Page ───────────────────────────────────────────── */
.about-hero {
  padding-top: calc(var(--nav-height) + var(--space-20));
  padding-bottom: var(--space-20);
}

.about-grid {
  display: grid;
  gap: var(--space-12);
  align-items: start;
}

@media (min-width: 860px) {
  .about-grid {
    grid-template-columns: 1fr 380px;
  }
}

.about-headline {
  font-size: clamp(var(--text-3xl), 4vw, var(--text-5xl));
  font-weight: var(--fw-light);
  line-height: var(--lh-tight);
  letter-spacing: -0.02em;
  margin-bottom: var(--space-6);
}

.about-body {
  font-size: var(--text-lg);
  color: var(--color-text-secondary);
  line-height: var(--lh-relaxed);
  max-width: 56ch;
}

.about-body p + p {
  margin-top: var(--space-5);
}

/* Skills grid */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--space-4);
}

.skill-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-6);
}

.skill-card__category {
  font-size: var(--text-xs);
  font-weight: var(--fw-medium);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: var(--space-4);
}

.skill-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.skill-list li {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.skill-list li::before {
  content: '';
  display: block;
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--color-text-muted);
  flex-shrink: 0;
}

/* Resume timeline */
.timeline {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.timeline-item {
  display: grid;
  grid-template-columns: 110px 1fr;
  gap: var(--space-8);
  position: relative;
  padding-bottom: var(--space-10);
}

.timeline-item:last-child {
  padding-bottom: 0;
}

.timeline-item__date {
  font-size: var(--text-xs);
  font-weight: var(--fw-medium);
  color: var(--color-text-muted);
  letter-spacing: 0.04em;
  padding-top: 3px;
  text-align: right;
}

.timeline-item__connector {
  position: absolute;
  left: 118px;
  top: 8px;
  bottom: 0;
  width: 1px;
  background: var(--color-border);
}

.timeline-item:last-child .timeline-item__connector {
  display: none;
}

.timeline-item__dot {
  position: absolute;
  left: 113px;
  top: 6px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--color-bg);
  border: 2px solid var(--color-border);
}

.timeline-item__content {
  padding-left: var(--space-8);
}

.timeline-item__role {
  font-size: var(--text-base);
  font-weight: var(--fw-medium);
  line-height: var(--lh-snug);
  margin-bottom: var(--space-1);
}

.timeline-item__company {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  margin-bottom: var(--space-3);
}

.timeline-item__bullets {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.timeline-item__bullets li {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  line-height: var(--lh-relaxed);
  padding-left: var(--space-4);
  position: relative;
}

.timeline-item__bullets li::before {
  content: '–';
  position: absolute;
  left: 0;
  color: var(--color-text-muted);
}

/* ── Homepage Sections ────────────────────────────────────── */
.about-strip {
  display: grid;
  gap: var(--space-10);
  align-items: center;
}

@media (min-width: 768px) {
  .about-strip {
    grid-template-columns: 1fr 1fr;
  }
}

.about-strip__heading {
  font-size: var(--text-3xl);
  font-weight: var(--fw-light);
  letter-spacing: -0.02em;
  line-height: var(--lh-snug);
  margin-bottom: var(--space-4);
}

.about-strip__body {
  font-size: var(--text-base);
  color: var(--color-text-secondary);
  line-height: var(--lh-relaxed);
  margin-bottom: var(--space-6);
}

/* Contact CTA */
.contact-cta {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  text-align: center;
}

.contact-cta__heading {
  font-size: clamp(var(--text-2xl), 3vw, var(--text-4xl));
  font-weight: var(--fw-light);
  letter-spacing: -0.02em;
  line-height: var(--lh-snug);
  margin-bottom: var(--space-4);
}

.contact-cta__sub {
  font-size: var(--text-base);
  color: var(--color-text-secondary);
  margin-bottom: var(--space-8);
  max-width: 44ch;
  margin-inline: auto;
}

.contact-cta__actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-4);
  flex-wrap: wrap;
}

/* ── Footer ───────────────────────────────────────────────── */
.footer {
  border-top: 1px solid var(--color-border);
  padding-block: var(--space-8);
}

.footer__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-4);
}

.footer__copy {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
}

.footer__links {
  display: flex;
  gap: var(--space-6);
}

.footer__link {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  transition: color var(--transition-fast);
}

.footer__link:hover {
  color: var(--color-text-primary);
}

/* ── Case Study Navigation ────────────────────────────────── */
.cs-nav-strip {
  border-top: 1px solid var(--color-border);
  padding-block: var(--space-12);
}

.cs-nav-strip__inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-4);
}

.cs-nav-strip__label {
  font-size: var(--text-xs);
  font-weight: var(--fw-medium);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: var(--space-1);
}

.cs-nav-strip__title {
  font-size: var(--text-base);
  font-weight: var(--fw-medium);
}

/* ── Responsive ───────────────────────────────────────────── */
@media (max-width: 768px) {
  :root {
    --space-24: 4rem;
    --space-32: 5rem;
  }

  .nav__links {
    display: none;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
    padding: var(--space-4);
  }

  .nav__links.open {
    display: flex;
  }

  .nav__link,
  .nav__cta {
    width: 100%;
    padding: var(--space-3) var(--space-2);
    border-radius: 0;
  }

  .nav__cta {
    margin-top: var(--space-2);
    border-radius: var(--radius-sm);
    text-align: center;
    justify-content: center;
  }

  .nav__hamburger {
    display: flex;
  }

  .timeline-item {
    grid-template-columns: 1fr;
    gap: var(--space-2);
  }

  .timeline-item__date {
    text-align: left;
  }

  .timeline-item__connector,
  .timeline-item__dot {
    display: none;
  }

  .timeline-item__content {
    padding-left: 0;
  }

  .cs-body {
    grid-template-columns: 1fr;
  }

  .cs-sidebar {
    position: static;
  }
}

@media (max-width: 480px) {
  .container {
    padding-inline: var(--space-5);
  }

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

  .cs-title {
    font-size: var(--text-3xl);
  }
}

/* ── Phone Screenshot Strip ───────────────────────────────── */
.phone-strip-wrapper {
  margin-block: var(--space-8);
}

.phone-strip-label {
  font-size: var(--text-xs);
  font-weight: var(--fw-medium);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: var(--space-4);
}

.phone-strip {
  display: flex;
  gap: var(--space-4);
  overflow-x: auto;
  padding-bottom: var(--space-4);
  padding-top: var(--space-2);
  /* Show partial next item as affordance to scroll */
  padding-right: var(--space-8);
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
  scrollbar-color: var(--color-border) transparent;
}

.phone-strip::-webkit-scrollbar {
  height: 4px;
}

.phone-strip::-webkit-scrollbar-track {
  background: transparent;
}

.phone-strip::-webkit-scrollbar-thumb {
  background: var(--color-border);
  border-radius: 2px;
}

.phone-strip__item {
  flex-shrink: 0;
  width: 175px;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.phone-strip__item-label {
  font-size: var(--text-xs);
  font-weight: var(--fw-medium);
  color: var(--color-text-muted);
  text-align: center;
  letter-spacing: 0.03em;
}

.phone-strip__frame {
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-md);
  border: 1px solid var(--color-border);
  background: #fff;
}

.phone-strip__frame img {
  width: 100%;
  height: auto;
  display: block;
}

.phone-strip__caption {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  text-align: center;
  line-height: var(--lh-snug);
}

/* Featured single phone screenshot */
.phone-featured-wrapper {
  margin-block: var(--space-8);
  text-align: center;
}

.phone-featured {
  width: 280px;
  margin: 0 auto var(--space-4);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--color-border);
}

.phone-featured img {
  width: 100%;
  height: auto;
  display: block;
}

.phone-featured__caption {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  max-width: 40ch;
  margin: 0 auto;
  line-height: var(--lh-relaxed);
}

/* Screen label under each strip item */
.phone-strip__item-label {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  text-align: center;
  padding: var(--space-2) var(--space-2) var(--space-3);
  border-top: 1px solid var(--color-border);
}

/* ── Accessibility ────────────────────────────────────────── */
:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  border: 0;
}

/* ── Animations ───────────────────────────────────────────── */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(16px); }
  to   { opacity: 1; transform: translateY(0); }
}

.animate-fade-up {
  animation: fadeUp 0.6s ease both;
}

.animate-delay-1 { animation-delay: 0.1s; }
.animate-delay-2 { animation-delay: 0.2s; }
.animate-delay-3 { animation-delay: 0.3s; }
.animate-delay-4 { animation-delay: 0.4s; }