/*
 * css/pages/case-studies.css
 * Phase 10 — Case Studies Page Rebuild
 *
 * CSS ISOLATION:
 *   All selectors are prefixed .cs- to avoid collision with
 *   global component classes (.cs-card, .cs-feat etc. are
 *   already defined in css/components.css from legacy extraction —
 *   this file adds ONLY new case-studies-specific layout classes
 *   and responsive overrides for this page.
 *
 * CSS LOAD ORDER:
 *   css/global.css (tokens + reset)
 *     ↓ css/utilities.css
 *       ↓ css/header.css
 *         ↓ css/footer.css
 *           ↓ css/components.css  (contains .cs-card, .cs-feat, .faq-*)
 *             ↓ css/pages/case-studies.css  ← this file
 *
 * DESIGN SYSTEM:
 *   Uses design tokens from css/global.css (via css/tokens.css).
 *   Does not introduce new color values.
 *   Uses: --bg, --bg2, --bg3, --purple, --purple2, --cyan, --white,
 *         --gray, --gray2, --gray3, --radius-md, --radius-pill,
 *         --duration-normal, --duration-fast, --space-*, --container-*
 */

/* ── Hero section extension ───────────────────────────────────────────── */
/*
 * The case-studies hero extends the shared .iph (inner page hero) pattern.
 * .cs-hero-section overrides bottom padding to accommodate the stats strip.
 */
.cs-hero-section {
  padding-bottom: 0;
}

/* ── Hero stats strip ─────────────────────────────────────────────────── */
.cs-hero-stats {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0;
  margin-top: 48px;
  background: var(--bg2);
  border: 1px solid var(--color-border, rgba(255,255,255,0.07));
  border-radius: var(--radius-md);
  padding: 24px 32px;
  flex-wrap: wrap;
}

.cs-hstat {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  padding: 0 32px;
  text-align: center;
}

.cs-hstat-num {
  font-family: var(--font-family-primary);
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 800;
  letter-spacing: -1.5px;
  background: var(--gradient-text);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
}

.cs-hstat-lbl {
  font-family: var(--font-family-mono);
  font-size: 11px;
  color: var(--color-gray);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  white-space: nowrap;
}

.cs-hstat-div {
  width: 1px;
  height: 40px;
  background: var(--color-gray3, rgba(255,255,255,0.07));
  flex-shrink: 0;
}

/* ── Featured section ─────────────────────────────────────────────────── */
.cs-featured-section {
  padding-top: 72px;
}

/*
 * .cs-feat is defined in css/components.css (legacy extraction).
 * .cs-feat-content is new — provides a named wrapper for the text side.
 */
.cs-feat-content {
  flex: 1;
  min-width: 0;
}

/* ── Studies section ──────────────────────────────────────────────────── */
.cs-studies-section {
  padding-top: 0;
}

/*
 * Filter navigation — visual only in Phase 10 (no JS filtering).
 * Uses native <button> elements with aria-pressed.
 * Keyboard: Enter/Space toggle aria-pressed via future JS or CSS.
 */
.cs-filters {
  margin-bottom: 40px;
}

.cs-filter-label {
  /* sr-only — visually hidden, accessible to screen readers */
}

.cs-filter-group {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  align-items: center;
}

.cs-filter-btn {
  font-family: var(--font-family-mono);
  font-size: var(--font-size-caption);
  letter-spacing: 0.04em;
  padding: 8px 17px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--color-border, rgba(255,255,255,0.09));
  background: rgba(255,255,255,0.04);
  color: var(--color-gray);
  cursor: pointer;
  transition: background var(--duration-fast) ease,
              border-color var(--duration-fast) ease,
              color var(--duration-fast) ease;
  line-height: 1;
}

.cs-filter-btn:hover {
  background: rgba(124,58,237,0.1);
  border-color: rgba(124,58,237,0.35);
  color: var(--color-purple2);
}

.cs-filter-btn:focus-visible {
  background: rgba(124,58,237,0.1);
  border-color: rgba(124,58,237,0.35);
  color: var(--color-purple2);
  outline: 2px solid var(--color-purple2);
  outline-offset: 2px;
}

.cs-filter-btn.cs-filter-active,
.cs-filter-btn[aria-pressed="true"] {
  background: var(--color-purple);
  border-color: transparent;
  color: var(--color-white);
}

/*
 * Case study grid — overrides legacy .cs-grid 3-col to use auto-fit
 * for better mobile handling. The legacy .cs-grid is already defined
 * in components.css; this provides a more controlled responsive version.
 */
.cs-studies-section .cs-grid {
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

/*
 * Case study card enhancements — the base .cs-card styles are in
 * css/components.css. These are case-studies-page-specific additions.
 */
.cs-title {
  font-size: clamp(16px, 1.8vw, 18px);
  font-weight: 700;
  letter-spacing: -0.5px;
  color: var(--color-white);
  margin-bottom: 10px;
  line-height: 1.35;
}

/* ── FAQ section ──────────────────────────────────────────────────────── */
.cs-faq-section {
  padding-top: 0;
}

/*
 * FAQ improvements — base .faq-* classes are in components.css.
 * Adding aria-expanded state styles for the rebuilt accessible markup.
 */
.faq-btn[aria-expanded="true"] .faq-icon {
  transform: rotate(45deg);
  background: rgba(124,58,237,0.18);
}

.faq-btn[aria-expanded="true"] {
  color: var(--color-purple2);
}

/* ── CTA section ──────────────────────────────────────────────────────── */
.cs-cta-section {
  /* Uses section-sm spacing */
}

.cs-cta-inner {
  text-align: center;
  max-width: 620px;
  margin: 0 auto;
}

.cs-cta-inner h2 {
  font-size: clamp(28px, 3.5vw, 42px);
  font-weight: 800;
  letter-spacing: -1.5px;
  color: var(--color-white);
  margin-bottom: 16px;
}

.cs-cta-inner p {
  font-size: var(--font-size-body-lg);
  color: var(--color-gray);
  max-width: 480px;
  margin: 0 auto 32px;
  line-height: 1.65;
}

.cs-cta-btns {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}

/* ── Responsive ───────────────────────────────────────────────────────── */

/* Tablet — 1024px */
@media (max-width: 1024px) {
  .cs-studies-section .cs-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* Mobile — 900px: stats strip compact */
@media (max-width: 900px) {
  .cs-hero-stats {
    padding: 20px 16px;
    gap: 4px;
  }

  .cs-hstat {
    padding: 8px 16px;
  }
}

/* Mobile — 768px: single column grid, CTA stacks */
@media (max-width: 768px) {
  .cs-studies-section .cs-grid {
    grid-template-columns: 1fr;
  }

  .cs-cta-btns {
    flex-direction: column;
    align-items: center;
  }

  .cs-cta-btns .btn-p,
  .cs-cta-btns .btn-g {
    width: 100%;
    max-width: 280px;
    justify-content: center;
  }

  .cs-filter-group {
    justify-content: flex-start;
  }
}

/* Small mobile — 600px: stats strip hides dividers */
@media (max-width: 600px) {
  .cs-hstat-div {
    display: none;
  }

  .cs-hero-stats {
    gap: 8px;
    justify-content: space-around;
  }
}

/* Very small — 360px */
@media (max-width: 360px) {
  .cs-filter-btn {
    font-size: 11px;
    padding: 6px 12px;
  }

  .cs-hero-stats {
    padding: 16px 12px;
  }

  .cs-hstat {
    padding: 4px 8px;
  }
}

/* ── Reduced motion ───────────────────────────────────────────────────── */
@media (prefers-reduced-motion: reduce) {
  .cs-filter-btn {
    transition: none !important;
  }
}

/* ── Case study card hidden state (filter, Phase 18) ────────────────────── */
/* Cards hidden by JS filter are removed from rendering AND from tab order   */
.cs-card[hidden] {
  display: none;
}