/* ── CASE STUDY PAGE STYLES ──────────────────────────────────── */

/* ── PAGE HERO (listing page) ─────────────────────────────── */
.page-hero {
  padding: calc(var(--nav-h) + var(--space-16)) 0 var(--space-16);
  position: relative;
}
.page-hero__inner { max-width: 720px; }
.page-hero__heading {
  font-size: var(--text-hero);
  font-family: var(--font-display);
  font-weight: 800;
  letter-spacing: -0.03em;
  margin: var(--space-4) 0 var(--space-6);
}
.page-hero__subtitle {
  font-size: var(--text-xl);
  color: var(--text-muted);
  line-height: 1.6;
}

/* ── CS LISTING GRID ────────────────────────────────────────── */
.cs-list { padding: var(--space-16) 0 var(--space-32); }
.cs-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-6);
}
@media (min-width: 768px) {
  .cs-grid { grid-template-columns: repeat(2, 1fr); }
}

.cs-card {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--r-xl);
  overflow: hidden;
  transition: border-color 0.2s, transform 0.2s, box-shadow 0.2s;
}
.cs-card:hover {
  border-color: var(--cs-color, var(--accent));
  transform: translateY(-4px);
  box-shadow: 0 12px 40px rgba(0,0,0,0.3), 0 0 0 1px var(--cs-color, var(--accent));
}

.cs-card__link {
  display: block;
  padding: var(--space-8);
  color: inherit;
  height: 100%;
}

.cs-card__top {
  display: flex;
  align-items: flex-start;
  gap: var(--space-4);
  margin-bottom: var(--space-6);
}
.cs-card__icon { font-size: 2.5rem; line-height: 1; flex-shrink: 0; }
.cs-card__meta { flex: 1; }
.cs-card__date {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--text-subtle);
  display: block;
  margin-bottom: var(--space-2);
}
.cs-card__tags { display: flex; flex-wrap: wrap; gap: var(--space-1); }

.cs-card__title {
  font-family: var(--font-display);
  font-size: var(--text-2xl);
  font-weight: 800;
  margin-bottom: var(--space-2);
  line-height: 1.2;
}
.cs-card__subtitle {
  font-size: var(--text-base);
  color: var(--cs-color, var(--accent));
  font-weight: 600;
  margin-bottom: var(--space-4);
}
.cs-card__summary {
  font-size: var(--text-sm);
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: var(--space-6);
}

/* Stats row on card */
.cs-card__stats {
  display: flex;
  gap: var(--space-4);
  flex-wrap: wrap;
  padding: var(--space-4) 0;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  margin-bottom: var(--space-6);
}
.cs-stat { text-align: center; flex: 1; min-width: 60px; }
.cs-stat__value {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: 800;
  color: var(--cs-color, var(--accent));
  display: block;
  line-height: 1.2;
}
.cs-stat__suffix { font-size: 0.7em; }
.cs-stat__label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--text-subtle);
}

.cs-card__cta {
  font-size: var(--text-sm);
  font-weight: 700;
  color: var(--cs-color, var(--accent));
  display: flex;
  align-items: center;
  gap: var(--space-2);
  transition: gap 0.2s;
}
.cs-card:hover .cs-card__cta { gap: var(--space-4); }

/* ── CS HERO (single page) ──────────────────────────────────── */
.cs-hero {
  padding: calc(var(--nav-h) + var(--space-12)) 0 var(--space-16);
  position: relative;
  overflow: hidden;
}
.cs-hero__bg {
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse 60% 60% at 70% 30%, rgba(var(--cs-color, 0,245,160), 0.05), transparent);
  pointer-events: none;
}
.cs-hero__inner { max-width: 860px; position: relative; z-index: 1; }

.cs-breadcrumb { margin-bottom: var(--space-6); }
.cs-breadcrumb ol {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  flex-wrap: wrap;
  list-style: none;
}
.cs-breadcrumb a {
  font-size: var(--text-sm);
  color: var(--text-muted);
  transition: color 0.2s;
}
.cs-breadcrumb a:hover { color: var(--text); }
.cs-breadcrumb li:last-child { color: var(--text-muted); font-size: var(--text-sm); }
.cs-breadcrumb li[aria-hidden] { color: var(--text-subtle); font-size: var(--text-xs); }

.cs-hero__icon { font-size: 3rem; margin-bottom: var(--space-4); }
.cs-hero__tags { display: flex; flex-wrap: wrap; gap: var(--space-2); margin-bottom: var(--space-4); }
.cs-hero__heading {
  font-family: var(--font-display);
  font-size: clamp(2rem, 6vw, 4rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.1;
  margin-bottom: var(--space-4);
}
.cs-hero__subtitle {
  font-size: var(--text-xl);
  color: var(--cs-color, var(--accent));
  font-weight: 600;
  margin-bottom: var(--space-6);
  line-height: 1.4;
}
.cs-hero__meta {
  display: flex;
  gap: var(--space-4);
  align-items: center;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--text-subtle);
  flex-wrap: wrap;
}

/* ── CS STATS SECTION ───────────────────────────────────────── */
.cs-stats-section {
  padding: var(--space-8) 0;
  background: var(--bg-surface);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}
.cs-stats-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-4);
}
@media (min-width: 640px) {
  .cs-stats-grid { grid-template-columns: repeat(4, 1fr); }
}
.cs-stat-card {
  text-align: center;
  padding: var(--space-6) var(--space-4);
}
.cs-stat-card__value {
  font-family: var(--font-display);
  font-size: var(--text-4xl);
  font-weight: 800;
  color: var(--cs-color, var(--accent));
  display: block;
  line-height: 1;
  margin-bottom: var(--space-2);
}
.cs-stat-card__suffix { font-size: 0.5em; vertical-align: top; padding-top: 0.3em; }
.cs-stat-card__label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--text-muted);
  letter-spacing: 0.05em;
}

/* ── CS CONTENT GRID ────────────────────────────────────────── */
.cs-content { padding: var(--space-16) 0 var(--space-32); }
.cs-content__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-12);
  align-items: start;
}
@media (min-width: 1024px) {
  .cs-content__grid {
    grid-template-columns: 200px 1fr;
    gap: var(--space-16);
  }
}

/* ── TOC ────────────────────────────────────────────────────── */
.cs-toc {
  display: none;
  position: sticky;
  top: calc(var(--nav-h) + var(--space-8));
}
@media (min-width: 1024px) { .cs-toc { display: block; } }
.cs-toc__inner { /* scroll if overflows viewport */ max-height: calc(100vh - var(--nav-h) - 4rem); overflow-y: auto; }
.cs-toc__label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--text-subtle);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: var(--space-4);
}
.cs-toc__list { display: flex; flex-direction: column; gap: var(--space-2); list-style: none; }
.cs-toc__list a {
  font-size: var(--text-sm);
  color: var(--text-muted);
  transition: color 0.2s;
  display: block;
  padding: var(--space-1) 0;
  border-left: 2px solid transparent;
  padding-left: var(--space-3);
}
.cs-toc__list a:hover,
.cs-toc__list a.active {
  color: var(--text);
  border-left-color: var(--accent);
}
.cs-toc__project-link {
  margin-top: var(--space-6);
  padding-top: var(--space-6);
  border-top: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

/* ── PROSE ──────────────────────────────────────────────────── */
.cs-prose { max-width: 720px; }
.cs-prose section { margin-bottom: var(--space-12); }
.cs-prose h2 {
  font-family: var(--font-display);
  font-size: var(--text-2xl);
  font-weight: 800;
  margin-bottom: var(--space-4);
  padding-top: var(--space-4);
  color: var(--text);
}
.cs-prose p {
  color: var(--text-muted);
  line-height: 1.8;
  margin-bottom: var(--space-4);
  font-size: var(--text-lg);
}
.cs-prose__highlight-section {
  background: var(--bg-surface);
  border-radius: var(--r-xl);
  padding: var(--space-8);
  border: 1px solid var(--border);
}
.cs-prose__blockquote {
  border-left: 3px solid var(--bq-color, var(--accent));
  padding: var(--space-4) var(--space-6);
  background: var(--accent-dim);
  border-radius: 0 var(--r-md) var(--r-md) 0;
}
.cs-prose__blockquote p {
  color: var(--text);
  font-style: italic;
  font-size: var(--text-lg);
}
.cs-prose__cta {
  margin-top: var(--space-16);
  padding-top: var(--space-8);
  border-top: 1px solid var(--border);
}

/* ── CARD CS BADGE ──────────────────────────────────────────── */
.card-cs-badge {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--amber);
  letter-spacing: 0.05em;
  margin-left: var(--space-2);
}

/* ── EMPTY STATE ────────────────────────────────────────────── */
.cs-empty {
  padding: var(--space-16) 0;
  text-align: center;
}

/* ── CASE STUDIES INDEX PAGE ─────────────────────────────────── */

/* Hero */
.cs-index-hero {
  padding: calc(var(--nav-h) + var(--space-16)) 0 var(--space-12);
  position: relative;
  overflow: hidden;
}
.cs-index-hero__bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 70% 60% at 10% 50%, var(--blob-1), transparent),
    radial-gradient(ellipse 40% 70% at 90% 20%, var(--blob-2), transparent);
  pointer-events: none;
}
.cs-index-hero__inner {
  max-width: 780px;
  position: relative;
  z-index: 1;
  margin-top: var(--space-8);
}
.cs-index-hero__label {
  display: flex;
  align-items: center;
  gap: var(--space-6);
  margin-bottom: var(--space-6);
}
.cs-index-hero__count {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--text-subtle);
  letter-spacing: 0.08em;
}
.cs-index-hero__heading {
  font-family: var(--font-display);
  font-size: clamp(2.4rem, 7vw, 5rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.05;
  margin-bottom: var(--space-6);
}
.cs-index-hero__desc {
  font-size: var(--text-lg);
  color: var(--text-muted);
  line-height: 1.7;
  max-width: 560px;
}

/* List section */
.cs-index-list {
  padding: var(--space-8) 0 var(--space-32);
}

/* Grid: featured top full-width, rest 2-col */
.cs-index-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
  border-radius: var(--r-xl);
  overflow: hidden;
}
@media (min-width: 768px) {
  .cs-index-grid > .cs-entry:not(.cs-entry--featured):nth-child(even) {
    border-left: 1px solid var(--border);
  }
  .cs-index-grid > :not(.cs-entry--featured) {
    /* two-column layout for non-featured */
  }
}

/* Entry base */
.cs-entry {
  background: var(--bg-surface);
  transition: background 0.2s;
}
.cs-entry:hover { background: var(--bg-elevated); }

.cs-entry__link {
  display: grid;
  grid-template-columns: 3rem 1fr 2rem;
  gap: var(--space-6);
  align-items: start;
  padding: var(--space-8);
  color: inherit;
  text-decoration: none;
  transition: gap 0.2s;
}
.cs-entry:hover .cs-entry__link { gap: var(--space-6); }
.cs-entry:hover .cs-entry__arrow { transform: translateX(4px); color: var(--cs-color, var(--accent)); }

/* Featured entry spans full width, bigger padding */
.cs-entry--featured .cs-entry__link {
  grid-template-columns: 4rem 1fr 2rem;
  padding: var(--space-12) var(--space-8);
  border-bottom: 1px solid var(--border);
}

/* Number */
.cs-entry__num {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--text-subtle);
  padding-top: 0.25em;
  letter-spacing: 0.05em;
}
.cs-entry--featured .cs-entry__num { font-size: var(--text-sm); }

/* Body */
.cs-entry__body { min-width: 0; }

.cs-entry__head {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-3);
  margin-bottom: var(--space-4);
}
.cs-entry__icon { color: var(--cs-color, var(--accent)); flex-shrink: 0; }
.cs-entry__tags { display: flex; flex-wrap: wrap; gap: var(--space-1); flex: 1; }
.cs-entry__date {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--text-subtle);
  margin-left: auto;
}

.cs-entry__title {
  font-family: var(--font-display);
  font-size: var(--text-2xl);
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: var(--space-2);
  color: var(--text);
}
.cs-entry--featured .cs-entry__title { font-size: var(--text-3xl); }

.cs-entry__subtitle {
  font-size: var(--text-base);
  color: var(--cs-color, var(--accent));
  font-weight: 600;
  margin-bottom: var(--space-4);
  line-height: 1.4;
}

.cs-entry__summary {
  font-size: var(--text-sm);
  color: var(--text-muted);
  line-height: 1.75;
  margin-bottom: var(--space-6);
  max-width: 680px;
}

/* Stats strip */
.cs-entry__stats {
  display: flex;
  gap: var(--space-8);
  flex-wrap: wrap;
  padding-top: var(--space-4);
  border-top: 1px solid var(--border);
  margin-top: var(--space-4);
}
.cs-entry__stat { text-align: left; }
.cs-entry__stat-val {
  display: block;
  font-family: var(--font-display);
  font-size: var(--text-2xl);
  font-weight: 800;
  color: var(--cs-color, var(--accent));
  line-height: 1;
}
.cs-entry--featured .cs-entry__stat-val { font-size: var(--text-3xl); }
.cs-entry__stat-val small { font-size: 0.55em; vertical-align: top; padding-top: 0.3em; }
.cs-entry__stat-lbl {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--text-subtle);
  margin-top: var(--space-1);
}

/* Arrow */
.cs-entry__arrow {
  color: var(--text-subtle);
  transition: transform 0.2s var(--ease-out), color 0.2s;
  padding-top: 0.3rem;
  flex-shrink: 0;
}

/* Back link */
.cs-back { padding: 0 0 var(--space-16); }
.cs-back__link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
  font-size: var(--text-sm);
  color: var(--text-muted);
  transition: color 0.2s, gap 0.2s;
}
.cs-back__link:hover { color: var(--accent); gap: var(--space-4); }

/* Two-column grid for non-featured on desktop */
@media (min-width: 768px) {
  .cs-index-grid {
    grid-template-columns: 1fr;
  }
  .cs-index-grid > .cs-entry--featured {
    grid-column: 1;
  }
  /* If we have more than 1 entry, the rest go 2-col */
  .cs-index-grid > .cs-entry:not(.cs-entry--featured) ~ .cs-entry:not(.cs-entry--featured) {
    /* handled by background grid */
  }
}

/* Non-featured 2-col wrapper */
@media (min-width: 768px) {
  .cs-index-grid {
    display: flex;
    flex-direction: column;
  }
  /* Non-featured entries share a row if consecutive */
  .cs-index-grid > .cs-entry:not(.cs-entry--featured) {
    display: grid;
    grid-template-columns: 1fr;
  }
}

/* ── RESPONSIVE: 2-up grid for non-featured entries ─────────── */
@media (min-width: 900px) {
  .cs-index-grid {
    display: grid !important;
    /* Featured spans all cols; rest auto-fill 2 per row */
    grid-template-columns: 1fr 1fr;
  }
  .cs-index-grid > .cs-entry--featured {
    grid-column: 1 / -1;
    border-bottom: 1px solid var(--border);
  }
}