/* ============================================================
   VENNEXIS — DETAILED CASE STUDY SYSTEM
   Long-form, scroll-driven case study layout.
   Structure modelled on the CCAoA FAP case study:
   Banner → Stats → Challenge → Building for Scale → Capabilities
   → Role → Process (sticky rail) → Pain Points → Results/KPIs
   → UI Interfaces → Reflections → CTA.
   Theme-aware (uses core tokens). Per-page accent via --cs-accent.
   ============================================================ */

.cs {
  --cs-accent: var(--action);
  --cs-accent-soft: color-mix(in srgb, var(--cs-accent) 16%, transparent);
  --cs-line: var(--border-color);
  --cs-panel: var(--card-bg);
  position: relative;
}

/* ── Scroll progress bar ─────────────────────────────────── */
.cs-progress {
  position: fixed;
  top: 0; left: 0;
  height: 3px;
  width: 0%;
  background: linear-gradient(90deg, var(--cs-accent), var(--action));
  z-index: 1200;
  transition: width .08s linear;
  pointer-events: none;
}

/* ── COVER BANNER ────────────────────────────────────────── */
.cs-banner {
  position: relative;
  min-height: 92vh;
  display: flex;
  align-items: flex-end;
  overflow: hidden;
  isolation: isolate;
  background: var(--neutral-950);
}
.cs-banner__media {
  position: absolute;
  inset: -14% 0 -14% 0;
  z-index: -2;
  will-change: transform;
}
.cs-banner__media img {
  width: 100%; height: 100%;
  object-fit: cover;
  display: block;
  filter: saturate(1.02);
}
.cs-banner__overlay {
  position: absolute;
  inset: 0;
  z-index: -1;
  background:
    radial-gradient(120% 90% at 78% 18%, var(--cs-accent-soft) 0%, transparent 55%),
    linear-gradient(180deg, rgba(7,12,22,.55) 0%, rgba(7,12,22,.72) 46%, rgba(7,12,22,.94) 100%);
}
.cs-banner__inner {
  width: 100%;
  padding: 0 0 clamp(3rem, 6vw, 6rem);
}
.cs-banner__tags {
  display: flex; flex-wrap: wrap; gap: .5rem;
  margin-bottom: 1.5rem;
}
.cs-tag {
  font-size: .72rem;
  letter-spacing: .08em;
  text-transform: uppercase;
  font-weight: 600;
  color: var(--aerospace-white);
  padding: .34rem .7rem;
  border: 1px solid rgba(248,250,252,.22);
  border-radius: 100px;
  background: rgba(248,250,252,.06);
  backdrop-filter: blur(6px);
}
.cs-banner__kicker {
  display: inline-flex; align-items: center; gap: .6rem;
  font-size: .8rem; font-weight: 700; letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--cs-accent);
  margin-bottom: 1.1rem;
}
.cs-banner__kicker::before {
  content: ""; width: 34px; height: 2px; background: var(--cs-accent);
}
.cs-banner__title {
  color: var(--aerospace-white);
  font-size: clamp(2.6rem, 6.4vw, 5.2rem);
  line-height: .98;
  letter-spacing: -.02em;
  font-weight: 800;
  max-width: 16ch;
  margin: 0 0 1.3rem;
}
.cs-banner__sub {
  color: var(--neutral-200);
  font-size: clamp(1.05rem, 1.6vw, 1.4rem);
  line-height: 1.5;
  max-width: 62ch;
  margin-bottom: 2rem;
}
.cs-banner__meta {
  display: flex; flex-wrap: wrap;
  gap: 1.5rem 2.6rem;
  padding-top: 1.6rem;
  border-top: 1px solid rgba(248,250,252,.16);
  max-width: 760px;
}
.cs-meta__label {
  display: block;
  font-size: .68rem; letter-spacing: .1em; text-transform: uppercase;
  color: var(--neutral-400);
  margin-bottom: .3rem;
}
.cs-meta__val {
  color: var(--aerospace-white);
  font-weight: 600; font-size: .98rem;
}
.cs-banner__scroll {
  position: absolute;
  left: 50%; bottom: 1.4rem; transform: translateX(-50%);
  display: flex; flex-direction: column; align-items: center; gap: .5rem;
  color: var(--neutral-300); font-size: .68rem; letter-spacing: .18em; text-transform: uppercase;
  z-index: 2;
}
.cs-banner__scroll span { width: 1px; height: 44px; background: linear-gradient(var(--cs-accent), transparent); animation: csScroll 1.8s ease-in-out infinite; }
@keyframes csScroll { 0%{transform:scaleY(0);transform-origin:top} 40%{transform:scaleY(1);transform-origin:top} 60%{transform:scaleY(1);transform-origin:bottom} 100%{transform:scaleY(0);transform-origin:bottom} }

/* ── HERO STAT BAND ──────────────────────────────────────── */
.cs-statband {
  background: var(--neutral-900);
  border-top: 1px solid var(--cs-line);
  border-bottom: 1px solid var(--cs-line);
}
.cs-statband__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 1px;
  background: var(--cs-line);
}
.cs-statcell {
  background: var(--neutral-900);
  padding: 2.6rem 1.8rem;
}
.cs-statcell__num {
  font-size: clamp(2.4rem, 4vw, 3.4rem);
  font-weight: 800; line-height: 1;
  letter-spacing: -.02em;
  color: var(--aerospace-white);
  margin-bottom: .55rem;
}
.cs-statcell__num em { color: var(--cs-accent); font-style: normal; }
.cs-statcell__num.is-accent { color: var(--cs-accent); }
.cs-statcell__label { color: var(--neutral-300); font-size: .92rem; line-height: 1.45; }

/* ── GENERIC SECTION PARTS ───────────────────────────────── */
.cs-eyebrow {
  display: inline-flex; align-items: center; gap: .65rem;
  font-size: .78rem; font-weight: 700; letter-spacing: .14em;
  text-transform: uppercase; color: var(--cs-accent);
  margin-bottom: 1.1rem;
}
.cs-eyebrow::before { content: ""; width: 28px; height: 2px; background: var(--cs-accent); }
.cs-lead { font-size: clamp(1.15rem, 1.8vw, 1.5rem); line-height: 1.5; color: var(--text-primary); font-weight: 500; }
.cs-body { color: var(--text-secondary); line-height: 1.7; }
.cs-body + .cs-body { margin-top: 1rem; }
.cs-divider { height: 1px; background: var(--cs-line); border: 0; margin: 0; transform-origin: left center; }

/* Two-column split (text + visual) */
.cs-split {
  display: grid;
  grid-template-columns: 1.05fr .95fr;
  gap: clamp(2rem, 5vw, 5rem);
  align-items: center;
}
.cs-split--rev .cs-split__media { order: -1; }
.cs-figure {
  border-radius: 8px; overflow: hidden;
  border: 1px solid var(--cs-line);
  background: var(--neutral-800);
  box-shadow: 0 30px 60px -30px rgba(0,0,0,.6);
}
.cs-figure img { width: 100%; height: 100%; object-fit: cover; display: block; }
.cs-figure--tall { aspect-ratio: 4/3; }
.cs-figcaption { font-size: .8rem; color: var(--text-muted); margin-top: .75rem; letter-spacing: .01em; }

/* ── OBJECTIVES (checklist) ──────────────────────────────── */
.cs-objectives {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1rem;
  margin-top: 2rem;
}
.cs-objective {
  display: flex; gap: .9rem; align-items: flex-start;
  padding: 1.2rem 1.3rem;
  background: var(--cs-panel);
  border: 1px solid var(--card-border);
  border-radius: 8px;
  transition: transform .25s ease, border-color .25s ease;
}
.cs-objective:hover { transform: translateY(-3px); border-color: var(--cs-accent); }
.cs-objective__tick {
  flex: 0 0 auto; width: 26px; height: 26px; border-radius: 50%;
  display: grid; place-items: center;
  background: var(--cs-accent-soft); color: var(--cs-accent);
  margin-top: 1px;
}
.cs-objective__tick svg { width: 14px; height: 14px; }
.cs-objective p { color: var(--text-primary); font-size: .96rem; line-height: 1.45; font-weight: 500; }

/* ── OPPORTUNITY / PULL QUOTE ────────────────────────────── */
.cs-quote {
  border-left: 3px solid var(--cs-accent);
  padding: .4rem 0 .4rem 2rem;
  margin: 0;
}
.cs-quote p {
  font-size: clamp(1.4rem, 2.8vw, 2.1rem);
  line-height: 1.35; font-weight: 600; letter-spacing: -.01em;
  color: var(--text-primary);
}
.cs-quote cite { display: block; margin-top: 1rem; font-style: normal; color: var(--cs-accent); font-size: .9rem; letter-spacing: .06em; text-transform: uppercase; font-weight: 700; }

/* ── THE GOAL (highlight card) ───────────────────────────── */
.cs-goal {
  position: relative;
  padding: clamp(2rem, 4vw, 3.2rem);
  border-radius: 12px;
  background:
    linear-gradient(135deg, var(--cs-accent-soft), transparent 60%),
    var(--neutral-800);
  border: 1px solid var(--cs-accent);
  overflow: hidden;
}
.cs-goal__label { font-size: .78rem; letter-spacing: .14em; text-transform: uppercase; color: var(--cs-accent); font-weight: 700; margin-bottom: 1rem; }
.cs-goal__text { font-size: clamp(1.3rem, 2.4vw, 1.9rem); line-height: 1.4; font-weight: 600; color: var(--aerospace-white); }
[data-theme="light"] .cs-goal__text { color: var(--text-primary); }

/* ── PROBLEMS IDENTIFIED ─────────────────────────────────── */
.cs-problems {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1rem;
  margin-top: 2rem;
}
.cs-problem {
  padding: 1.5rem;
  background: var(--cs-panel);
  border: 1px solid var(--card-border);
  border-radius: 10px;
  border-top: 2px solid var(--cs-accent);
  transition: transform .25s ease;
}
.cs-problem:hover { transform: translateY(-4px); }
.cs-problem__num { font-size: .78rem; font-weight: 700; color: var(--cs-accent); letter-spacing: .1em; margin-bottom: .6rem; }
.cs-problem p { color: var(--text-secondary); font-size: .95rem; line-height: 1.5; }
.cs-problem strong { color: var(--text-primary); font-weight: 600; }

/* ── CAPABILITIES GRID ───────────────────────────────────── */
.cs-capgrid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 1px;
  background: var(--cs-line);
  border: 1px solid var(--cs-line);
  border-radius: 10px;
  overflow: hidden;
}
.cs-capcol { background: var(--card-bg); padding: 1.8rem; }
.cs-capcol__title {
  font-size: .82rem; letter-spacing: .06em; text-transform: uppercase;
  color: var(--cs-accent); font-weight: 700; margin-bottom: 1rem;
  display: flex; align-items: center; gap: .5rem;
}
.cs-capcol__list { display: flex; flex-wrap: wrap; gap: .4rem; }
.cs-caption-chip {
  font-size: .8rem; color: var(--text-secondary);
  padding: .32rem .7rem; border: 1px solid var(--card-border);
  border-radius: 100px; background: var(--bg-secondary);
}

/* ── ROLE ────────────────────────────────────────────────── */
.cs-role { display: grid; grid-template-columns: 1fr 1.1fr; gap: clamp(2rem,5vw,4rem); align-items: start; }
.cs-role__tags { display: flex; flex-wrap: wrap; gap: .5rem; margin-top: 1.5rem; }
.cs-resp { list-style: none; padding: 0; margin: 0; display: grid; gap: .1rem; }
.cs-resp li {
  display: flex; gap: 1rem; align-items: flex-start;
  padding: 1rem 0;
  border-bottom: 1px solid var(--cs-line);
  color: var(--text-secondary); line-height: 1.55;
}
.cs-resp li::before {
  content: ""; flex: 0 0 auto; width: 8px; height: 8px; margin-top: .5rem;
  background: var(--cs-accent); border-radius: 50%;
}
.cs-resp li:last-child { border-bottom: 0; }

/* ── PROCESS (sticky rail + phases) ──────────────────────── */
.cs-process { display: grid; grid-template-columns: 240px 1fr; gap: clamp(2rem, 5vw, 5rem); align-items: start; }
.cs-rail { position: sticky; top: 120px; align-self: start; }
.cs-rail__title { font-size: .72rem; letter-spacing: .14em; text-transform: uppercase; color: var(--text-muted); margin-bottom: 1.2rem; }
.cs-rail__list { list-style: none; padding: 0; margin: 0; display: grid; gap: .1rem; }
.cs-rail__item {
  display: flex; gap: .8rem; align-items: center;
  padding: .7rem .8rem;
  border-left: 2px solid var(--cs-line);
  color: var(--text-muted);
  font-size: .9rem; font-weight: 600;
  cursor: pointer;
  transition: color .25s ease, border-color .25s ease, background .25s ease;
  border-radius: 0 6px 6px 0;
}
.cs-rail__item:hover { color: var(--text-secondary); }
.cs-rail__num { font-size: .72rem; opacity: .7; min-width: 1.4em; }
.cs-rail__item.is-active {
  color: var(--cs-accent);
  border-left-color: var(--cs-accent);
  background: var(--cs-accent-soft);
}
.cs-phases { display: grid; gap: clamp(3rem, 6vw, 5.5rem); }
.cs-phase { scroll-margin-top: 110px; }
.cs-phase__head { display: flex; align-items: baseline; gap: 1rem; margin-bottom: 1.3rem; }
.cs-phase__num {
  font-size: 1rem; font-weight: 800; color: var(--cs-accent);
  border: 1px solid var(--cs-accent); border-radius: 6px;
  padding: .2rem .55rem; letter-spacing: .02em;
}
.cs-phase__title { font-size: clamp(1.5rem, 2.6vw, 2rem); font-weight: 700; letter-spacing: -.01em; color: var(--text-primary); }
.cs-activities { list-style: none; padding: 0; margin: 1.2rem 0 0; display: grid; gap: .6rem; }
.cs-activities li { position: relative; padding-left: 1.6rem; color: var(--text-secondary); line-height: 1.55; }
.cs-activities li::before {
  content: ""; position: absolute; left: 0; top: .5rem;
  width: 8px; height: 8px; border: 2px solid var(--cs-accent); border-radius: 2px;
}
.cs-outcome {
  margin-top: 1.5rem;
  display: flex; gap: .9rem; align-items: flex-start;
  padding: 1.1rem 1.3rem;
  background: var(--cs-accent-soft);
  border: 1px solid color-mix(in srgb, var(--cs-accent) 35%, transparent);
  border-radius: 8px;
}
.cs-outcome__tag { flex: 0 0 auto; font-size: .7rem; font-weight: 800; letter-spacing: .1em; text-transform: uppercase; color: var(--cs-accent); padding-top: .15rem; }
.cs-outcome p { color: var(--text-primary); font-size: .95rem; line-height: 1.55; }

/* ── PAIN POINTS (segment columns) ───────────────────────── */
.cs-pains {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1rem;
  margin-top: 1.6rem;
}
.cs-paincol {
  background: var(--cs-panel);
  border: 1px solid var(--card-border);
  border-radius: 10px;
  padding: 1.5rem;
}
.cs-paincol__seg {
  display: flex; align-items: center; gap: .6rem;
  font-weight: 700; color: var(--text-primary); margin-bottom: 1rem;
  padding-bottom: .8rem; border-bottom: 1px solid var(--cs-line);
}
.cs-paincol__seg svg { width: 20px; height: 20px; color: var(--cs-accent); }
.cs-paincol ul { list-style: none; padding: 0; margin: 0; display: grid; gap: .7rem; }
.cs-paincol li { color: var(--text-secondary); font-size: .9rem; line-height: 1.5; padding-left: 1.1rem; position: relative; }
.cs-paincol li::before { content: "–"; position: absolute; left: 0; color: var(--cs-accent); }

/* ── KPI BEFORE / AFTER TABLE ────────────────────────────── */
.cs-kpi {
  width: 100%;
  border-collapse: collapse;
  margin-top: 1.6rem;
  border: 1px solid var(--cs-line);
  border-radius: 10px;
  overflow: hidden;
}
.cs-kpi th, .cs-kpi td { padding: 1rem 1.2rem; text-align: left; border-bottom: 1px solid var(--cs-line); }
.cs-kpi thead th { font-size: .72rem; letter-spacing: .1em; text-transform: uppercase; color: var(--text-muted); background: var(--bg-secondary); }
.cs-kpi td:first-child { font-weight: 600; color: var(--text-primary); }
.cs-kpi__before { color: var(--text-muted); }
.cs-kpi__after { color: var(--cs-accent); font-weight: 700; }
.cs-kpi tr:last-child td { border-bottom: 0; }

/* ── UI SCREENS GALLERY ──────────────────────────────────── */
.cs-gallery { display: grid; gap: 1rem; }
.cs-gallery__wide {
  border-radius: 10px; overflow: hidden; border: 1px solid var(--cs-line);
  background: var(--neutral-800);
}
.cs-gallery__wide img { width: 100%; display: block; }
.cs-gallery__row { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
.cs-gallery__row .cs-gallery__wide img { aspect-ratio: 4/3; object-fit: cover; }

/* ── REFLECTIONS ─────────────────────────────────────────── */
.cs-reflections { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 1rem; margin-top: 1.8rem; }
.cs-reflection {
  padding: 1.6rem; border-radius: 10px;
  background: var(--cs-panel); border: 1px solid var(--card-border);
}
.cs-reflection__idx { font-size: 1.4rem; font-weight: 800; color: var(--cs-accent); margin-bottom: .6rem; }
.cs-reflection p { color: var(--text-secondary); line-height: 1.55; font-size: .95rem; }

/* section rhythm helpers */
.cs-section { padding: clamp(3.5rem, 8vw, 7rem) 0; }
.cs-section--tight { padding: clamp(2.5rem, 5vw, 4rem) 0; }
.cs-maxw { max-width: 760px; }
.cs-mt-2 { margin-top: 2rem; }
.cs-mt-3 { margin-top: 3rem; }

/* ── RESPONSIVE ──────────────────────────────────────────── */
@media (max-width: 900px) {
  .cs-split, .cs-role { grid-template-columns: 1fr; }
  .cs-split--rev .cs-split__media { order: 0; }
  .cs-process { grid-template-columns: 1fr; }
  .cs-rail {
    position: sticky; top: 64px; z-index: 40;
    background: var(--bg-primary);
    margin: 0 -1.25rem; padding: .5rem 1.25rem;
    border-bottom: 1px solid var(--cs-line);
  }
  .cs-rail__title { display: none; }
  .cs-rail__list { grid-auto-flow: column; grid-auto-columns: max-content; overflow-x: auto; gap: .4rem; scrollbar-width: none; }
  .cs-rail__list::-webkit-scrollbar { display: none; }
  .cs-rail__item { border-left: 0; border-bottom: 2px solid var(--cs-line); border-radius: 0; white-space: nowrap; padding: .5rem .7rem; }
  .cs-rail__item.is-active { border-left: 0; border-bottom-color: var(--cs-accent); background: transparent; }
  .cs-rail__num { display: none; }
}
@media (max-width: 620px) {
  .cs-banner { min-height: 88vh; }
  .cs-banner__meta { gap: 1.1rem 1.8rem; }
  .cs-gallery__row { grid-template-columns: 1fr; }
}
@media (prefers-reduced-motion: reduce) {
  .cs-banner__scroll span { animation: none; }
}