/* ============================================
   CASE STUDY STYLESHEET
   Inherits tokens/fonts from the main site,
   but can be used standalone on any /work/ page.
   ============================================ */

:root {
  --bg:          #F6F1EB;
  --bg-alt:      #EDE7DC;
  --surface:     #E6DDD0;
  --ink:         #1C1814;
  --ink-muted:   #6B6058;
  --ink-faint:   #A89E94;
  --accent:      #9A6B3F;
  --accent-light:#C49A72;
  --accent-bg:   #F0E6D6;
  --border:      #D6CEC4;

  --font-serif:  'Cormorant Garamond', Georgia, serif;
  --font-sans:   'DM Sans', system-ui, sans-serif;

  --max-w:       1120px;
  --prose-w:     68ch;
  --ease-out:    cubic-bezier(0.22, 1, 0.36, 1);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--ink);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }

/* -------- UTILITY -------- */
.container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 clamp(1.25rem, 5vw, 2.5rem);
}

/* -------- NAV -------- */
.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  background: rgba(246, 241, 235, 0.92);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 clamp(1.25rem, 5vw, 2.5rem);
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav-logo {
  font-family: var(--font-serif);
  font-size: 1.15rem;
  font-weight: 500;
  color: var(--ink);
  transition: color 0.2s;
}
.nav-logo:hover { color: var(--accent); }
.nav-back {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.82rem;
  font-weight: 500;
  letter-spacing: 0.04em;
  color: var(--ink-muted);
  transition: color 0.2s, gap 0.2s var(--ease-out);
}
.nav-back:hover { color: var(--accent); gap: 0.6rem; }
.nav-back .arrow { font-size: 0.9rem; transition: transform 0.2s var(--ease-out); }
.nav-back:hover .arrow { transform: translateX(-3px); }

/* -------- CASE STUDY HERO -------- */
.cs-hero {
  padding-top: calc(64px + clamp(3.5rem, 8vw, 6rem));
  padding-bottom: clamp(3rem, 6vw, 5rem);
  border-bottom: 1px solid var(--border);
}
.cs-hero .container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: clamp(2.5rem, 5vw, 5rem);
  align-items: end;
}
.cs-hero-left {}
.cs-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.7rem;
  font-weight: 500;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 1.25rem;
}
.cs-title {
  font-family: var(--font-serif);
  font-size: clamp(2.4rem, 5vw, 4rem);
  font-weight: 500;
  line-height: 1.1;
  color: var(--ink);
  margin-bottom: 1.25rem;
}
.cs-summary {
  font-size: clamp(1rem, 1.5vw, 1.15rem);
  color: var(--ink-muted);
  max-width: 52ch;
  line-height: 1.65;
}
.cs-meta {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  padding: 2rem;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: 2px;
  align-self: end;
}
.cs-meta-item {}
.cs-meta-label {
  font-size: 0.68rem;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin-bottom: 0.3rem;
}
.cs-meta-value {
  font-size: 0.92rem;
  color: var(--ink);
}
.cs-meta-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-top: 0.3rem;
}
.cs-meta-tags span {
  font-size: 0.72rem;
  font-weight: 500;
  padding: 0.2rem 0.6rem;
  background: var(--surface);
  border-radius: 2px;
  color: var(--ink-muted);
}
.cs-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--accent);
  transition: gap 0.2s var(--ease-out), color 0.2s;
}
.cs-link:hover { color: var(--ink); gap: 0.65rem; }

/* -------- BODY CONTENT -------- */
.cs-body {
  padding: clamp(3.5rem, 7vw, 6rem) 0;
}
.cs-body .container {
  max-width: var(--prose-w);
}

/* Prose typography */
.cs-body h2 {
  font-family: var(--font-serif);
  font-size: clamp(1.6rem, 2.5vw, 2.2rem);
  font-weight: 500;
  line-height: 1.2;
  color: var(--ink);
  margin-top: 3rem;
  margin-bottom: 1rem;
}
.cs-body h2:first-child { margin-top: 0; }
.cs-body h3 {
  font-family: var(--font-sans);
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  margin-top: 2.5rem;
  margin-bottom: 0.75rem;
}
.cs-body p {
  font-size: 1rem;
  color: var(--ink-muted);
  line-height: 1.8;
  margin-bottom: 1.25rem;
  max-width: 66ch;
}
.cs-body strong { color: var(--ink); font-weight: 500; }
.cs-body ul, .cs-body ol {
  margin-bottom: 1.25rem;
  padding-left: 1.25rem;
  list-style: none;
}
.cs-body ul li, .cs-body ol li {
  font-size: 1rem;
  color: var(--ink-muted);
  line-height: 1.75;
  padding: 0.35rem 0;
  padding-left: 1rem;
  border-bottom: 1px solid var(--surface);
  position: relative;
}
.cs-body ul li::before {
  content: '—';
  position: absolute;
  left: -1rem;
  color: var(--accent-light);
  font-size: 0.85rem;
}
.cs-body ol { counter-reset: ol-counter; }
.cs-body ol li { counter-increment: ol-counter; }
.cs-body ol li::before {
  content: counter(ol-counter, decimal-leading-zero);
  position: absolute;
  left: -1.5rem;
  font-size: 0.72rem;
  font-weight: 500;
  color: var(--accent);
  top: 0.6rem;
}

/* Callout / highlight block */
.callout {
  margin: 2.5rem 0;
  padding: 1.75rem 2rem;
  background: var(--accent-bg);
  border-left: 3px solid var(--accent);
  border-radius: 0 2px 2px 0;
}
.callout p {
  color: var(--ink);
  font-size: 1.05rem;
  margin-bottom: 0;
}
.callout strong { color: var(--accent); }

/* Result stat blocks */
.cs-results {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 1.5px;
  background: var(--border);
  border: 1.5px solid var(--border);
  margin: 2.5rem 0;
}
.cs-result-item {
  background: var(--bg);
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}
.cs-result-number {
  font-family: var(--font-serif);
  font-size: 3rem;
  font-weight: 500;
  line-height: 1;
  color: var(--accent);
}
.cs-result-label {
  font-size: 0.82rem;
  color: var(--ink-muted);
  line-height: 1.4;
}

/* Image block */
.cs-image {
  margin: 2.5rem 0;
  border: 1px solid var(--border);
  border-radius: 2px;
  overflow: hidden;
}
.cs-image img { width: 100%; }
.cs-image figcaption {
  padding: 0.75rem 1rem;
  font-size: 0.78rem;
  color: var(--ink-faint);
  background: var(--bg-alt);
  border-top: 1px solid var(--border);
}

/* Code block (for prompt engineering case studies) */
.cs-code {
  margin: 2rem 0;
  background: #1C1814;
  border-radius: 4px;
  overflow: hidden;
}
.cs-code-label {
  padding: 0.5rem 1rem;
  font-size: 0.68rem;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent-light);
  border-bottom: 1px solid rgba(255,255,255,0.08);
}
.cs-code pre {
  padding: 1.5rem;
  overflow-x: auto;
  font-family: 'Courier New', Courier, monospace;
  font-size: 0.85rem;
  line-height: 1.65;
  color: #E6DDD0;
  white-space: pre-wrap;
}

/* -------- NEXT PROJECT NAV -------- */
.cs-nav {
  border-top: 1px solid var(--border);
  padding: clamp(2rem, 4vw, 3.5rem) 0;
  background: var(--bg-alt);
}
.cs-nav .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}
.cs-nav-label {
  font-size: 0.68rem;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin-bottom: 0.4rem;
}
.cs-nav-link {
  font-family: var(--font-serif);
  font-size: 1.3rem;
  font-weight: 500;
  color: var(--ink);
  transition: color 0.2s;
}
.cs-nav-link:hover { color: var(--accent); }
.cs-nav-right { text-align: right; }
.cs-nav-all {
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--accent);
  letter-spacing: 0.03em;
  padding: 0.6rem 1.25rem;
  border: 1px solid var(--border);
  border-radius: 2px;
  transition: all 0.2s;
}
.cs-nav-all:hover { background: var(--ink); border-color: var(--ink); color: var(--bg); }

/* -------- RESPONSIVE -------- */
@media (max-width: 768px) {
  .cs-hero .container { grid-template-columns: 1fr; }
  .cs-meta { margin-top: 0; }
  .cs-results { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 480px) {
  .cs-results { grid-template-columns: 1fr; }
}