/* ─────────────────────────────────────────────
   Case Study — shared stylesheet
   1:1 token + component vocabulary alignment with
   Kenneth Lopes Portfolio.html (v2). Cream/forest editorial.
   ───────────────────────────────────────────── */

:root {
  /* Tokens (lifted from portfolio.html — keep in sync) */
  --bg:        #F2EBDA;
  --bg-2:      #E8E0CC;
  --ink:       #1B2A1B;
  --ink-2:     #3A4A3A;
  --muted:     #7A8A7A;
  --line:      rgba(27,42,27,0.14);
  --accent:    #2D4A2B;
  --accent-2:  #5E7030;
  --pop:       #C76F3D;
  --gutter:    clamp(24px, 6vw, 100px);

  --font-display: 'Fraunces', Georgia, serif;
  --font-italic:  'Instrument Serif', Georgia, serif;
  --font-body:    'Inter Tight', system-ui, sans-serif;
  --font-mono:    'JetBrains Mono', ui-monospace, monospace;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  background: var(--bg); color: var(--ink);
  font-family: var(--font-body);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; height: auto; }

.wrap { max-width: 1280px; margin: 0 auto; padding: 0 var(--gutter); }
section[id] { scroll-margin-top: 80px; }

/* ── TOP NAV (mirrors portfolio's .topnav) ── */
.nav-stack { position: sticky; top: 0; z-index: 100; }
.topnav { background: var(--bg); border-bottom: 1px solid var(--line); }
.topnav-inner {
  max-width: 1280px; margin: 0 auto;
  padding: 18px var(--gutter);
  display: grid; grid-template-columns: 1fr auto 1fr;
  align-items: center; gap: 24px;
}
.topnav-brand {
  font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.2em;
  text-transform: uppercase; color: var(--ink); justify-self: start;
}
.topnav-links { display: flex; gap: 32px; justify-content: center; }
.topnav-link {
  font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.18em;
  text-transform: uppercase; color: var(--muted); font-weight: 700;
  transition: color 0.15s;
}
.topnav-link:hover, .topnav-link.is-active { color: var(--ink); }
.topnav-cta {
  justify-self: end;
  font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.18em;
  text-transform: uppercase;
  padding: 10px 18px; border: 1.5px solid var(--ink); color: var(--ink);
  transition: background 0.15s, color 0.15s;
}
.topnav-cta:hover { background: var(--ink); color: var(--bg); }

/* "← All work" back link sits in the subnav row */
.subnav { background: rgba(242,235,218,0.92); backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px); }
.subnav-inner {
  max-width: 1280px; margin: 0 auto;
  padding: 10px var(--gutter);
  display: flex; justify-content: space-between; align-items: center;
  gap: 16px; flex-wrap: wrap;
}
.subnav-trail {
  display: flex; gap: 8px; align-items: center; flex-wrap: wrap;
  font-family: var(--font-mono); font-size: 10px;
  letter-spacing: 0.18em; text-transform: uppercase; color: var(--muted);
}
.subnav-trail a { color: var(--muted); transition: color 0.15s; }
.subnav-trail a:hover { color: var(--ink); }
.subnav-trail .sep { opacity: 0.45; }
.subnav-trail .current { color: var(--ink); }
.subnav-back {
  font-family: var(--font-mono); font-size: 10px;
  letter-spacing: 0.18em; text-transform: uppercase; color: var(--ink);
  border-bottom: 1px solid var(--ink); padding-bottom: 2px;
}
.subnav-back:hover { color: var(--accent); border-color: var(--accent); }

/* ── HERO (mirrors portfolio .hero pattern + .section-header-row) ── */
.cs-hero { padding: 80px 0 56px; border-bottom: 1px solid var(--line); }
.cs-hero-eyebrow {
  display: inline-flex; align-items: center; gap: 10px;
  font-family: var(--font-mono); font-size: 10px;
  letter-spacing: 0.2em; text-transform: uppercase; color: var(--accent);
  margin-bottom: 28px;
}
.cs-hero-eyebrow::before {
  content: ''; width: 7px; height: 7px; border-radius: 50%;
  background: var(--accent);
}
.cs-hero-title {
  font-family: var(--font-display);
  font-size: clamp(56px, 8vw, 110px);
  font-weight: 600; letter-spacing: -0.04em; line-height: 0.92;
  color: var(--ink); max-width: 18ch;
}
/* Italic emphasis word with olive underline strip — matches .hero-name-italic */
.cs-hero-title em {
  font-family: var(--font-italic);
  font-style: italic; font-weight: 400;
  color: var(--accent);
  background-image: linear-gradient(transparent 65%, rgba(94,112,48,0.45) 65%, rgba(94,112,48,0.45) 92%, transparent 92%);
  background-repeat: no-repeat;
  padding: 0 0.06em;
}
.cs-hero-sub {
  margin-top: 28px;
  font-family: var(--font-italic); font-style: italic;
  font-size: clamp(18px, 1.8vw, 24px);
  line-height: 1.45; color: var(--ink-2);
  max-width: 56ch;
}
/* 3-column meta strip: Role / Scope / Timeline */
.cs-hero-meta {
  margin-top: 44px;
  display: grid; grid-template-columns: repeat(3, 1fr);
  border-top: 1.5px solid var(--line);
  border-bottom: 1.5px solid var(--line);
}
.cs-hero-meta div {
  padding: 22px 24px 22px 0;
  border-right: 1px solid var(--line);
}
.cs-hero-meta div:last-child { border-right: none; padding-right: 0; }
.cs-hero-meta dt {
  font-family: var(--font-mono); font-size: 9px;
  letter-spacing: 0.2em; text-transform: uppercase; color: var(--muted);
  margin-bottom: 10px;
}
.cs-hero-meta dd {
  font-family: var(--font-display); font-size: clamp(18px, 2vw, 24px);
  font-weight: 500; letter-spacing: -0.02em; color: var(--ink);
  line-height: 1.2;
}

/* ── STAT STRIP (4-cell, mirrors portfolio .stats-bar/.stats-inner) ── */
.cs-stats { margin-top: 40px; }
.cs-stats-inner {
  display: grid; grid-template-columns: repeat(4, 1fr);
  border: 1.5px solid var(--line);
  background: rgba(27,42,27,0.05);
}
.cs-stat-cell {
  padding: 32px clamp(16px, 2.2vw, 32px);
  border-right: 1px solid var(--line);
  min-width: 0;
}
.cs-stat-cell:last-child { border-right: none; }
.cs-stat-num {
  font-family: var(--font-display);
  font-size: clamp(36px, 3.6vw, 48px);
  font-weight: 400; letter-spacing: -0.04em; line-height: 1;
  white-space: nowrap;
}
.cs-stat-num--ink   { color: var(--ink); }
.cs-stat-num--accent{ color: var(--accent); }
.cs-stat-num--olive { color: var(--accent-2); }
.cs-stat-num--pop   { color: var(--pop); }
.cs-stat-desc {
  font-family: var(--font-mono); font-size: 9px;
  letter-spacing: 0.18em; text-transform: uppercase;
  color: var(--muted); margin-top: 10px;
}

/* ── NUMBERED SECTION HEADER (mirrors portfolio .section-header-row) ── */
.cs-section { padding: 80px 0; border-top: 1px solid var(--line); }
.cs-section-header {
  display: grid; grid-template-columns: 130px 1fr auto;
  align-items: baseline; gap: 0 32px; margin-bottom: 48px;
}
.cs-section-eyebrow {
  font-family: var(--font-mono); font-size: 10px;
  letter-spacing: 0.2em; text-transform: uppercase; color: var(--muted);
  padding-top: 12px;
}
.cs-section-meta {
  font-family: var(--font-mono); font-size: 10px;
  letter-spacing: 0.14em; text-transform: uppercase; color: var(--muted);
  padding-top: 12px; white-space: nowrap;
}
.cs-section-heading {
  font-family: var(--font-display);
  font-size: clamp(40px, 5vw, 68px);
  font-weight: 400; letter-spacing: -0.03em; line-height: 1;
}
.cs-section-heading em {
  font-family: var(--font-italic); font-style: italic; color: var(--accent);
}

/* ── EYEBROW TAGS (mirrors portfolio .cs-tag) ── */
.cs-tag {
  font-family: var(--font-mono); font-size: 11px;
  letter-spacing: 0.18em; text-transform: uppercase;
  color: var(--ink); border: 1px solid var(--ink);
  padding: 6px 12px; display: inline-block; background: var(--bg);
}
.cs-tag--ink { background: var(--ink); color: var(--bg); border-color: var(--ink); }
.cs-tag--accent { background: var(--accent); color: var(--bg); border-color: var(--accent); }

/* ── CARDS (1px line, no radius, hover -4/-4 with offset accent shadow) ── */
.cs-card {
  background: var(--bg-2);
  border: 1px solid var(--line);
  padding: 28px;
  position: relative;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}
.cs-card--ink { background: var(--ink); color: var(--bg); }
.cs-card--ink .cs-card-tag { color: rgba(242,235,218,0.85); border-color: rgba(242,235,218,0.35); }
.cs-link { display: block; }
.cs-link:hover .cs-card,
.cs-card-hover:hover {
  transform: translate(-4px, -4px);
  box-shadow: 8px 8px 0 var(--accent);
}
.cs-card--accent-shadow:hover { box-shadow: 8px 8px 0 var(--accent-2); }

/* ── 2-up + 3-up content grids ── */
.cs-grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.cs-grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.cs-grid-2 > *, .cs-grid-3 > * { display: flex; flex-direction: column; }

/* Card title row (mirrors .cs-caption-row from portfolio) */
.cs-card-caption {
  display: flex; justify-content: space-between; align-items: baseline;
  margin-top: 18px; gap: 16px;
}
.cs-card-title {
  font-family: var(--font-display);
  font-size: clamp(22px, 2.4vw, 32px);
  font-weight: 400; letter-spacing: -0.025em; line-height: 1.1;
}
.cs-card-title em { font-family: var(--font-italic); font-style: italic; }
.cs-card-figure {
  font-family: var(--font-display);
  font-size: clamp(22px, 2.4vw, 32px);
  font-weight: 400; letter-spacing: -0.03em;
  color: var(--accent); white-space: nowrap;
}
.cs-card-figure--pop { color: var(--pop); }
.cs-card-sub {
  font-family: var(--font-mono); font-size: 10px;
  letter-spacing: 0.1em; color: var(--muted);
  margin-top: 6px;
}

/* ── PROBLEM / SOLUTION SPLIT (ink-bordered, eyebrow tags) ── */
.ps-split { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; margin-top: 24px; }
.ps-card {
  background: var(--bg-2);
  border: 1px solid var(--line);
  padding: 32px;
  position: relative;
}
.ps-card--problem { border-left: 3px solid var(--ink-2); }
.ps-card--solution { border-left: 3px solid var(--accent); }
.ps-card .cs-tag { margin-bottom: 18px; }
.ps-card h3 {
  font-family: var(--font-display);
  font-size: clamp(22px, 2.2vw, 28px); font-weight: 400;
  letter-spacing: -0.025em; line-height: 1.15;
  color: var(--ink); margin-bottom: 14px;
}
.ps-card h3 em { font-family: var(--font-italic); font-style: italic; color: var(--accent); }
.ps-card ul { list-style: none; padding: 0; }
.ps-card li {
  position: relative; padding: 10px 0 10px 22px;
  font-size: 15px; line-height: 1.55; color: var(--ink-2);
  border-bottom: 1px solid var(--line);
}
.ps-card li:last-child { border-bottom: none; }
.ps-card li::before {
  content: ''; position: absolute; left: 0; top: 20px;
  width: 12px; height: 1px; background: var(--accent);
}
.ps-card--problem li::before { background: var(--ink-2); }
.ps-card li strong { color: var(--ink); font-weight: 600; }

/* ── PERFORMANCE STRIP (dark ink panel, big numbers) ── */
.perf-strip {
  margin-top: 48px;
  background: var(--ink); color: var(--bg);
  padding: 48px clamp(28px, 4vw, 64px);
  display: grid; grid-template-columns: 2fr 1fr;
  gap: 40px; align-items: end;
}
.perf-strip-eyebrow {
  font-family: var(--font-mono); font-size: 10px;
  letter-spacing: 0.2em; text-transform: uppercase;
  color: rgba(242,235,218,0.5); margin-bottom: 16px;
}
.perf-strip-num {
  font-family: var(--font-display);
  font-size: clamp(56px, 7vw, 96px);
  font-weight: 400; letter-spacing: -0.04em; line-height: 0.95;
  color: var(--bg);
}
.perf-strip-num em {
  font-family: var(--font-italic); font-style: italic; color: var(--pop);
}
.perf-strip-cap {
  font-family: var(--font-italic); font-style: italic;
  font-size: clamp(16px, 1.4vw, 18px);
  color: rgba(242,235,218,0.7); line-height: 1.5;
  max-width: 32ch;
}

/* ── CHART HOSTS (so lifted SVGs just slot in) ── */
.cs-chart-card {
  background: var(--bg-2);
  border: 1px solid var(--line);
  padding: 24px; min-height: 360px;
  display: flex; flex-direction: column;
  position: relative;
}
.cs-chart-card--ink { background: var(--ink); color: var(--bg); border-color: var(--ink); }
.cs-chart-card--ink .cs-chart-card-tag { color: rgba(242,235,218,0.85); border-color: rgba(242,235,218,0.3); background: transparent; }
.cs-chart-card-tag {
  font-family: var(--font-mono); font-size: 10px;
  letter-spacing: 0.18em; text-transform: uppercase;
  border: 1px solid var(--line); padding: 6px 12px;
  background: var(--bg); color: var(--ink);
  align-self: flex-start;
}
.cs-chart-card-meta {
  font-family: var(--font-mono); font-size: 9px;
  letter-spacing: 0.1em; text-transform: uppercase; color: var(--muted);
}
.cs-chart-card h4 {
  font-family: var(--font-display);
  font-size: clamp(22px, 2.4vw, 32px); font-weight: 400;
  letter-spacing: -0.02em; line-height: 1.1;
  margin-top: 16px;
}
.cs-chart-card h4 em { font-family: var(--font-italic); font-style: italic; }
.cs-chart-area { flex: 1; margin-top: 12px; position: relative; }

/* ── ASSET GALLERY (image frames; placeholder when missing) ── */
.cs-gallery {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px;
  margin-top: 24px;
}
.cs-gallery-frame {
  background: var(--bg-2);
  border: 1px solid var(--line);
  padding: 12px;
  display: flex; flex-direction: column; gap: 10px;
}
.cs-gallery-frame img {
  width: 100%; aspect-ratio: 4/3; object-fit: cover;
  border: 1px solid var(--line);
}
/* Placeholder slot for assets not yet provided */
.cs-gallery-placeholder {
  width: 100%; aspect-ratio: 4/3;
  border: 1px dashed var(--line);
  background: repeating-linear-gradient(135deg, transparent 0 12px, rgba(27,42,27,0.04) 12px 24px);
  display: flex; align-items: center; justify-content: center;
  font-family: var(--font-mono); font-size: 9px;
  letter-spacing: 0.18em; text-transform: uppercase;
  color: var(--muted); text-align: center; padding: 12px;
}
.cs-gallery-cap {
  font-family: var(--font-mono); font-size: 9px;
  letter-spacing: 0.14em; text-transform: uppercase; color: var(--muted);
  display: flex; justify-content: space-between;
}
.cs-gallery-cap strong { font-family: var(--font-body); font-weight: 600; color: var(--ink-2); letter-spacing: 0.02em; text-transform: none; font-size: 13px; }

/* ── PREV / NEXT FOOT NAV ── */
.foot-nav {
  display: grid; grid-template-columns: 1fr 1fr;
  border-top: 1px solid var(--line);
  margin-top: 80px;
}
.foot-nav-cell {
  padding: 36px var(--gutter);
  display: flex; flex-direction: column; gap: 8px;
  transition: background 0.2s;
  min-height: 140px; justify-content: center;
}
.foot-nav-cell:first-child { border-right: 1px solid var(--line); }
.foot-nav-cell:hover { background: var(--bg-2); }
.foot-nav-cell:nth-child(2) { text-align: right; align-items: flex-end; }
.foot-nav-dir {
  font-family: var(--font-mono); font-size: 10px;
  letter-spacing: 0.2em; text-transform: uppercase; color: var(--muted);
}
.foot-nav-title {
  font-family: var(--font-display);
  font-size: clamp(22px, 2.4vw, 30px);
  font-weight: 400; letter-spacing: -0.025em; line-height: 1.1;
  color: var(--ink);
}
.foot-nav-title em { font-family: var(--font-italic); font-style: italic; color: var(--accent); }

/* ── FOOTER (mirrors portfolio .footer / .foot dark bar) ── */
.foot {
  background: var(--ink);
  border-top: 1px solid rgba(242,235,218,0.1);
}
.foot-inner {
  max-width: 1280px; margin: 0 auto;
  padding: 20px var(--gutter);
  display: flex; justify-content: space-between; align-items: center;
  flex-wrap: wrap; gap: 12px;
}
.foot span, .foot a {
  font-family: var(--font-mono); font-size: 9px;
  letter-spacing: 0.14em; text-transform: uppercase;
  color: rgba(242,235,218,0.3);
}
.foot a:hover { color: rgba(242,235,218,0.65); }
.foot nav { display: flex; gap: 24px; }


/* ── PICTURE wrapper safety: keep block display so inner img sizes correctly ── */
.cs-chart-card picture,
.cs-gallery-frame picture { display: block; width: 100%; }

/* ── RESPONSIVE (mirrors portfolio breakpoints) ── */
@media (max-width: 980px) {
  .cs-grid-2, .cs-grid-3, .ps-split { grid-template-columns: 1fr; }
  .cs-section-header { grid-template-columns: 1fr; gap: 8px; margin-bottom: 28px; }
  .cs-section-meta { display: none; }
  .perf-strip { grid-template-columns: 1fr; gap: 24px; }
  .cs-stats-inner { grid-template-columns: 1fr 1fr; }
  .cs-stat-cell:nth-child(2) { border-right: none; }
  .cs-stat-cell:nth-child(3) { border-top: 1px solid var(--line); }
  .cs-hero-meta { grid-template-columns: 1fr; }
  .cs-hero-meta div { border-right: none; border-bottom: 1px solid var(--line); }
  .cs-hero-meta div:last-child { border-bottom: none; }
  .cs-gallery { grid-template-columns: 1fr; }
  .topnav-links { display: none; }
  .topnav-inner { grid-template-columns: 1fr auto; }
  .foot-nav { grid-template-columns: 1fr; }
  .foot-nav-cell:first-child { border-right: none; border-bottom: 1px solid var(--line); }
  .foot-nav-cell:nth-child(2) { text-align: left; align-items: flex-start; }
}
@media (max-width: 520px) {
  .cs-stats-inner { grid-template-columns: 1fr; }
  .cs-stat-cell { border-right: none; border-bottom: 1px solid var(--line); }
  .cs-stat-cell:last-child { border-bottom: none; }
}