/* PM Portfolio — Case-study (project detail) template.
 * Follows DESIGN.md §8 detail template: sticky top bar, title + metadata,
 * cover, narrow reading measure (<=640px), mono overlines per beat,
 * impact metrics, quote blocks, next-project nav. Uses design-system tokens. */

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
html, body {
  margin: 0;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-sans);
  -webkit-font-smoothing: antialiased;
}
::selection { background: var(--color-primary); color: var(--color-surface); }

.serif { font-family: var(--font-serif); }
.mono  { font-family: var(--font-mono); }

/* ---------------- sticky top bar ---------------- */
.cs-bar {
  position: sticky;
  top: 0;
  z-index: var(--z-nav);
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px clamp(20px, 4vw, 44px);
  background: color-mix(in srgb, var(--color-bg) 82%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border);
}
.cs-bar a { color: var(--color-text); text-decoration: none; }
.cs-bar .wordmark { font-family: var(--font-serif); font-size: 19px; }
.cs-bar .back {
  font-family: var(--font-sans);
  font-size: 13px;
  letter-spacing: var(--tracking-nav);
  text-transform: uppercase;
  color: var(--color-text-muted);
  transition: color var(--motion-micro) var(--ease-standard);
}
.cs-bar .back:hover { color: var(--color-primary); }

/* detail-template bar: ← Index | wordmark | 01 / 03 (per the "Project detail"
   screen in the design source) */
.cs-bar--detail { display: grid; grid-template-columns: 1fr auto 1fr; align-items: center; }
.cs-bar--detail .back { justify-self: start; }
.cs-bar--detail .count {
  justify-self: end;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: var(--tracking-nav);
  text-transform: uppercase;
  color: var(--color-text-muted);
}

/* ---------------- layout ---------------- */
.cs-wrap {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 clamp(20px, 5vw, 64px);
}
.cs-measure { max-width: var(--measure); margin-inline: auto; }

/* visual blocks (card grids, media) escape the reading measure while staying
   centered — prose keeps the measure, artifacts get room to breathe */
.cs-breakout {
  width: min(92vw, 960px);
  margin-inline: calc((100% - min(92vw, 960px)) / 2);
}

/* ---------------- title block ---------------- */
.cs-hero {
  padding: clamp(56px, 9vw, 104px) 0 clamp(32px, 5vw, 48px);
  text-align: center;
}
.cs-eyebrow {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin: 0 0 20px;
}
.cs-hero h1 {
  margin: 0;
  font-family: var(--font-serif);
  font-weight: 300;
  font-size: clamp(40px, 7vw, 84px);
  line-height: 1.0;
  letter-spacing: 0.005em;
  text-wrap: balance;
}
.cs-lede {
  margin: 18px auto 0;
  max-width: 52ch;
  font-family: var(--font-serif);
  font-style: italic;
  font-size: clamp(18px, 2.2vw, 24px);
  line-height: 1.4;
  color: var(--color-text-body);
}
.cs-facts {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px 28px;
  margin: 32px auto 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-text-muted);
}
.cs-facts b { color: var(--color-text); font-weight: 500; }

/* ---------------- cover ---------------- */
.cs-cover {
  aspect-ratio: 16 / 9;
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--color-surface-alt);
  border: 1px solid var(--color-border);
}
.cs-cover img { width: 100%; height: 100%; object-fit: cover; display: block; }

/* mood cover: dappled backdrop + an overlaid positioning line (for projects
   without product screenshots) */
.cs-cover--mood {
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 0 8%;
  background:
    linear-gradient(rgba(242,241,232,.28), rgba(242,241,232,.60)),
    url("../design-system/uploads/background.png") center / cover;
}
.cs-cover--mood p {
  margin: 0;
  max-width: 24ch;
  font-family: var(--font-serif);
  font-style: italic;
  font-size: clamp(20px, 3.2vw, 38px);
  line-height: 1.3;
  color: var(--color-text);
}

/* ---------------- body sections ---------------- */
.cs-section { padding: clamp(56px, 8vw, 88px) 0 0; }
.cs-label {
  display: flex;
  align-items: baseline;
  gap: 14px;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: var(--tracking-label);
  text-transform: uppercase;
  color: var(--color-accent);
  margin: 0 0 22px;
}
.cs-label::before { content: attr(data-n); color: var(--color-text-muted); }
.cs-h2 {
  font-family: var(--font-serif);
  font-weight: 400;
  font-size: clamp(28px, 3.4vw, 40px);
  line-height: 1.1;
  letter-spacing: -0.01em;
  margin: 0 0 22px;
}
.cs-body p {
  font-size: 16.5px;
  line-height: 1.75;
  color: var(--color-text-body);
  margin: 0 0 18px;
}
.cs-body p:last-child { margin-bottom: 0; }
.cs-body strong { color: var(--color-text); font-weight: 600; }
.cs-body a { color: var(--color-primary); text-decoration: none; border-bottom: 1px solid var(--color-accent); }
.cs-body a:hover { color: var(--color-secondary); border-color: var(--color-secondary); }

/* ---------------- paired stakeholder perspectives ---------------- */
.cs-perspectives {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-top: 26px;
  overflow: hidden;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background: var(--color-border);
}
.cs-perspective {
  padding: 26px 24px;
  background: var(--color-surface);
}
.cs-card-label {
  display: block;
  margin-bottom: 14px;
  color: var(--color-accent);
  font-family: var(--font-mono);
  font-size: 9.5px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}
.cs-perspective h3 {
  margin: 0 0 14px;
  color: var(--color-text);
  font-family: var(--font-serif);
  font-size: 25px;
  font-weight: 500;
  line-height: 1.2;
}
.cs-perspective p,
.cs-body .cs-perspective p:last-child {
  margin: 0;
  color: var(--color-text-body);
  font-size: 14.5px;
  line-height: 1.65;
}

/* ---------------- impact metrics ---------------- */
.cs-metrics {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
  margin-top: 4px;
}
.cs-metric {
  padding: 26px 20px;
  text-align: center;
  border-right: 1px solid var(--color-border);
}
.cs-metric:last-child { border-right: 0; }
.cs-metric b {
  display: block;
  font-family: var(--font-serif);
  font-weight: 400;
  font-size: clamp(34px, 4.4vw, 48px);
  line-height: 1;
  letter-spacing: -0.01em;
}
.cs-metric span {
  display: block;
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 9.5px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--color-text-muted);
}

/* ---------------- quote ---------------- */
.cs-quote {
  margin: 26px 0;
  padding-left: 22px;
  border-left: 2px solid var(--color-accent);
}
.cs-quote:last-child { margin-bottom: 0; }
.cs-quote p {
  font-family: var(--font-serif);
  font-style: italic;
  font-size: clamp(21px, 2.6vw, 27px);
  line-height: 1.4;
  color: var(--color-text-body);
  margin: 0;
}
.cs-quote cite {
  display: block;
  margin-top: 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-style: normal;
  letter-spacing: 0.1em;
  color: var(--color-accent);
}

/* ---------------- figures ---------------- */
.cs-figure { margin: 8px 0 0; }
.cs-figure figcaption {
  margin-top: 14px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--color-text-muted);
  text-align: center;
}
.cs-shots {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 20px;
}
.cs-shot {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--color-surface);
  box-shadow: var(--shadow-card);
}
.cs-shot img { width: 100%; display: block; }
/* ---------------- comparison / before-after ---------------- */
.cs-compare {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--color-border);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  margin: 4px 0 0;
}
.cs-compare-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--color-border);
}
.cs-compare-cell {
  background: var(--color-surface);
  padding: 18px 22px;
}
.cs-compare-cell .k {
  font-family: var(--font-mono);
  font-size: 9.5px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--color-accent);
  display: block;
  margin-bottom: 8px;
}
.cs-compare-cell.was .v { color: var(--color-text-muted); }
.cs-compare-cell .v { font-size: 14.5px; line-height: 1.5; }

/* ---------------- layered / process list ---------------- */
.cs-steps { display: grid; gap: 1px; background: var(--color-border); border: 1px solid var(--color-border); border-radius: var(--radius-lg); overflow: hidden; margin: 4px 0 0; }
.cs-step { background: var(--color-surface); padding: 20px 24px; display: grid; grid-template-columns: 40px 1fr; gap: 18px; align-items: baseline; }
.cs-step .n { font-family: var(--font-serif); font-size: 22px; color: var(--color-accent); }
.cs-step > span:nth-child(2) { display: block; }
.cs-step .t { display: block; font-weight: 600; font-size: 15.5px; }
.cs-step .d { display: block; color: var(--color-text-muted); font-size: 14px; line-height: 1.6; margin-top: 6px; }

/* pull points / list */
.cs-list { list-style: none; margin: 4px 0 0; padding: 0; }
.cs-list li { padding: 16px 0; border-top: 1px solid var(--color-border); font-size: 16px; line-height: 1.65; color: var(--color-text-body); }
.cs-list li:first-child { border-top: 0; }
.cs-list li strong { color: var(--color-text); }
.cs-body .cs-footnote {
  margin-top: 24px;
  padding-top: 16px;
  border-top: 1px solid var(--color-border);
  color: var(--color-text-muted);
  font-size: 12.5px;
  line-height: 1.6;
}

/* ---------------- next-project nav + footer ---------------- */
.cs-next {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  margin-top: clamp(64px, 9vw, 104px);
  padding: 26px 0;
  border-top: 1px solid var(--color-border);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-text-muted);
}
.cs-next a { color: inherit; text-decoration: none; }
.cs-next a:hover { color: var(--color-primary); }
.cs-next .nxt {
  font-family: var(--font-serif);
  font-size: 17px;
  font-style: italic;
  letter-spacing: 0.02em;
  text-transform: none;
}
.cs-foot {
  padding: 20px 0 40px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  text-align: center;
}

/* ---------------- left table of contents (margin index) ----------------
   Built by components/case-study-toc.js from the numbered .cs-label markers.
   A quiet editorial rail: mono micro-labels, olive dash slides in beside the
   active section. Only shown when the viewport has a genuine left margin. */
.cs-toc {
  position: fixed;
  left: clamp(20px, 3vw, 44px);
  top: 50%;
  transform: translateY(-50%);
  z-index: var(--z-sticky);
}
.cs-toc ol {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 15px;
}
.cs-toc a {
  position: relative;
  display: inline-block;
  max-width: 168px;
  color: var(--color-text-muted);
  text-decoration: none;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: var(--tracking-label);
  text-transform: uppercase;
  line-height: 1.5;
  transition:
    color var(--motion-micro) var(--ease-standard),
    transform var(--motion-ui) var(--ease-standard);
}
.cs-toc a .n {
  margin-right: 9px;
  color: var(--color-accent);
  transition: color var(--motion-micro) var(--ease-standard);
}
.cs-toc a::before {
  content: "";
  position: absolute;
  left: -26px;
  top: 0.75em;
  width: 17px;
  height: 1px;
  background: var(--color-primary);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--motion-ui) var(--ease-standard);
}
.cs-toc a:hover { color: var(--color-primary); }
.cs-toc a.active {
  color: var(--color-primary);
  transform: translateX(6px);
}
.cs-toc a.active .n { color: var(--color-primary); }
.cs-toc a.active::before { transform: scaleX(1); }

@media (prefers-reduced-motion: no-preference) {
  .cs-toc { animation: cs-toc-in 500ms var(--ease-standard) 300ms backwards; }
  @keyframes cs-toc-in {
    from { opacity: 0; transform: translateY(calc(-50% + 10px)); }
    to   { opacity: 1; transform: translateY(-50%); }
  }
}

/* the rail needs a real margin: content column is 960px at its widest, so
   below ~1360px the rail would collide with breakout media — hide it */
@media (max-width: 1359px) { .cs-toc { display: none; } }

/* anchor jumps clear the fixed site header */
.cs-section { scroll-margin-top: 96px; }

/* ---------------- responsive ---------------- */
@media (max-width: 620px) {
  .cs-breakout { width: 100%; margin-inline: 0; }
  .cs-perspectives { grid-template-columns: 1fr; }
  .cs-compare-row { grid-template-columns: 1fr; }
  .cs-metric { border-right: 0; border-bottom: 1px solid var(--color-border); }
  .cs-metric:last-child { border-bottom: 0; }
}