/* ═══════════════════════════════════════════════════════════════════════════
   case-study.css — shared stylesheet for all case study detail pages
   ═══════════════════════════════════════════════════════════════════════════
   Loaded after /page.css and /service-bim-delivery.css.
   Page-local prefix: .cs-  (case study)
   Owns: hero, overview row, 2-col shell, gallery (featured + thumbs),
         lightbox, sticky walkthrough form, what-to-expect block,
         related cards.
   .steps is provided by service-bim-delivery.css — do not redefine here.
   ═══════════════════════════════════════════════════════════════════════════ */

/* ═══════════════ §01 Hero · compact text-only ═══════════════ */
.cs-hero {
  background: var(--paper);
  padding: clamp(28px, 3vw, 44px) clamp(40px, 5vw, 80px) clamp(18px, 2vw, 28px);
  border-bottom: 1px solid var(--paper-rule-2);
}
.cs-hero-in {
  max-width: var(--sp-container, 1720px);
  margin: 0 auto;
}
.cs-hero .eye {
  font-family: var(--mono); font-weight: 700;
  font-size: 11px; letter-spacing: 0.22em;
  text-transform: uppercase; color: var(--red);
  display: inline-flex; align-items: center; gap: 12px;
  margin-bottom: 12px;
}
.cs-hero .eye .bar { width: 22px; height: 2px; background: var(--red); }
.cs-hero h1 {
  font-family: var(--sans); font-weight: 700;
  font-size: clamp(28px, 3.2vw, 44px);
  line-height: 1.04; letter-spacing: -0.025em;
  color: var(--ink); margin: 0 0 10px;
  max-width: 30ch; text-wrap: balance;
}
.cs-hero h1 em {
  font-family: var(--serif); font-style: italic;
  color: var(--red); font-weight: 400;
}
.cs-hero .teaser {
  font-family: var(--sans);
  font-size: clamp(14px, 1vw, 16px);
  line-height: 1.5; color: var(--ink-soft);
  margin: 0; max-width: 80ch;
}

/* ═══════════════ §02 Overview · 5-col data row ═══════════════ */
.cs-overview {
  background: var(--paper-warm);
  padding: 14px clamp(40px, 5vw, 80px);
  border-bottom: 1px solid var(--paper-rule-2);
}
.cs-overview-in {
  max-width: var(--sp-container, 1720px);
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: clamp(20px, 3vw, 48px);
}
.cs-meta { display: flex; flex-direction: column; gap: 4px; }
.cs-meta .k {
  font-family: var(--mono); font-weight: 700;
  font-size: 10.5px; letter-spacing: 0.22em;
  text-transform: uppercase; color: var(--red);
}
.cs-meta .v {
  font-family: var(--sans); font-weight: 600;
  font-size: 14px; line-height: 1.35;
  color: var(--ink);
}
@media (max-width: 1000px) {
  .cs-overview-in { grid-template-columns: repeat(2, 1fr); gap: 18px; }
}

/* ═══════════════ §03 Body shell · 2-col, sticky form scrolls ALL content ═══════════════
   Single shell wraps gallery + what-to-expect + related on the left.
   The form sticks on the right and stays visible until the shell ends. */
.cs-shell {
  background: var(--paper);
  padding: clamp(16px, 2vw, 28px) clamp(40px, 5vw, 80px) clamp(56px, 5vw, 80px);
}
.cs-shell-in {
  max-width: var(--sp-container, 1720px);
  margin: 0 auto;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 400px;
  gap: clamp(40px, 4vw, 64px);
  align-items: start;
}
.cs-main { min-width: 0; display: flex; flex-direction: column; gap: clamp(56px, 5vw, 80px); }
.cs-form-sticky {
  position: sticky;
  top: 80px;       /* clear sticky nav (~58-60px) + breathing room */
  align-self: start;
}

/* ═══════════════ Gallery · featured + thumbnail row ═══════════════ */
.cs-gallery { display: flex; flex-direction: column; gap: 8px; }

/* Featured — taller, fills available fold space */
.cs-gal-featured {
  height: clamp(320px, 56vh, 560px);
  width: 100%;
  background:
    linear-gradient(135deg, rgba(0,0,0,0.05), rgba(0,0,0,0.01)),
    var(--paper-warm);
  border: 1px solid var(--paper-rule-2);
  position: relative; overflow: hidden;
  cursor: zoom-in;
}
.cs-gal-featured::before, .cs-gal-featured::after {
  content: ''; position: absolute; inset: 0;
  background: linear-gradient(to top right, transparent calc(50% - 0.5px), rgba(0,0,0,0.05), transparent calc(50% + 0.5px));
  pointer-events: none;
}
.cs-gal-featured::after { transform: scaleX(-1); }
.cs-gal-featured img {
  position: absolute; inset: 0;
  width: 100%; height: 100%; object-fit: cover;
  z-index: 1;
}
.cs-gal-featured .label {
  position: absolute; left: 16px; bottom: 16px;
  z-index: 2;
  font-family: var(--mono); font-weight: 700;
  font-size: 11px; letter-spacing: 0.18em;
  text-transform: uppercase;
  color: #fff;
  background: rgba(0,0,0,0.65);
  backdrop-filter: blur(4px);
  padding: 6px 11px;
  border: 1px solid rgba(255,255,255,0.12);
}
.cs-gal-featured .zoom-hint {
  position: absolute; right: 16px; top: 16px; z-index: 2;
  font-family: var(--mono); font-weight: 700;
  font-size: 10px; letter-spacing: 0.16em;
  text-transform: uppercase;
  color: #fff;
  background: rgba(0,0,0,0.55);
  padding: 5px 9px;
  border: 1px solid rgba(255,255,255,0.12);
  display: inline-flex; align-items: center; gap: 6px;
  opacity: 0.85; transition: opacity 0.2s ease;
}
.cs-gal-featured:hover .zoom-hint { opacity: 1; }

/* Thumbnail row — small, fits under featured */
.cs-gal-thumbs {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 8px;
}
.cs-gal-thumb {
  height: clamp(70px, 10vh, 110px);
  background:
    linear-gradient(135deg, rgba(0,0,0,0.05), rgba(0,0,0,0.01)),
    var(--paper-warm);
  border: 1px solid var(--paper-rule-2);
  position: relative; overflow: hidden;
  cursor: pointer;
  transition: border-color 0.18s ease, transform 0.18s ease;
  padding: 0; margin: 0;
}
.cs-gal-thumb::before, .cs-gal-thumb::after {
  content: ''; position: absolute; inset: 0;
  background: linear-gradient(to top right, transparent calc(50% - 0.5px), rgba(0,0,0,0.05), transparent calc(50% + 0.5px));
  pointer-events: none;
}
.cs-gal-thumb::after { transform: scaleX(-1); }
.cs-gal-thumb img {
  position: absolute; inset: 0;
  width: 100%; height: 100%; object-fit: cover;
  z-index: 1;
}
.cs-gal-thumb:hover { transform: translateY(-1px); border-color: var(--ink); }
.cs-gal-thumb.is-active {
  border-color: var(--red);
  box-shadow: 0 0 0 1px var(--red) inset;
}
@media (max-width: 700px) {
  .cs-gal-thumbs { grid-template-columns: repeat(3, 1fr); }
}

/* ═══════════════ Lightbox · click featured to enlarge ═══════════════ */
.cs-lightbox {
  position: fixed; inset: 0; z-index: 9999;
  background: rgba(0,0,0,0.92);
  display: none; align-items: center; justify-content: center;
  padding: 40px;
}
.cs-lightbox.is-open { display: flex; }
.cs-lightbox-inner {
  position: relative;
  max-width: min(1400px, 95vw);
  max-height: 90vh;
  width: 100%; height: 100%;
  display: flex; align-items: center; justify-content: center;
}
.cs-lightbox-img {
  max-width: 100%; max-height: 100%;
  object-fit: contain;
  background:
    linear-gradient(135deg, rgba(255,255,255,0.04), rgba(255,255,255,0.01)),
    #1a1a1a;
  border: 1px solid rgba(255,255,255,0.08);
}
.cs-lightbox-caption {
  position: absolute; left: 0; right: 0; bottom: -28px;
  text-align: center;
  font-family: var(--mono); font-weight: 700;
  font-size: 11px; letter-spacing: 0.18em;
  text-transform: uppercase;
  color: rgba(255,255,255,0.85);
}
.cs-lightbox-close {
  position: absolute; top: -36px; right: 0;
  background: transparent; border: 1px solid rgba(255,255,255,0.25);
  color: #fff;
  width: 32px; height: 32px;
  display: inline-flex; align-items: center; justify-content: center;
  cursor: pointer; padding: 0;
  font-family: var(--mono); font-size: 16px; font-weight: 700;
  transition: border-color 0.18s ease, background 0.18s ease;
}
.cs-lightbox-close:hover { border-color: #fff; background: rgba(255,255,255,0.08); }
.cs-lightbox-nav {
  position: absolute; top: 50%; transform: translateY(-50%);
  background: rgba(0,0,0,0.6); border: 1px solid rgba(255,255,255,0.18);
  color: #fff;
  width: 44px; height: 44px;
  display: inline-flex; align-items: center; justify-content: center;
  cursor: pointer; padding: 0;
  font-family: var(--mono); font-size: 18px; font-weight: 700;
  transition: background 0.18s ease;
}
.cs-lightbox-nav:hover { background: rgba(0,0,0,0.85); }
.cs-lightbox-nav.prev { left: -56px; }
.cs-lightbox-nav.next { right: -56px; }
@media (max-width: 900px) {
  .cs-lightbox-nav.prev { left: 8px; }
  .cs-lightbox-nav.next { right: 8px; }
}

/* ═══════════════ Sticky walkthrough request form ═══════════════ */
.cs-form {
  background: var(--paper-warm);
  border-top: 2px solid var(--red);
  padding: 26px 24px 22px;
}
.cs-form .badge {
  display: inline-block;
  font-family: var(--mono); font-weight: 700;
  font-size: 10.5px; letter-spacing: 0.16em;
  text-transform: uppercase; color: var(--paper);
  background: var(--ink);
  padding: 5px 10px;
  margin-bottom: 14px;
}
.cs-form h2 {
  font-family: var(--sans); font-weight: 700;
  font-size: 22px; line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--ink); margin: 0 0 8px;
}
.cs-form h2 em {
  font-family: var(--serif); font-style: italic;
  color: var(--red); font-weight: 400;
}
.cs-form .sub {
  font-family: var(--sans);
  font-size: 13px; line-height: 1.5;
  color: var(--ink-soft); margin: 0 0 18px;
}
.cs-form .field { display: flex; flex-direction: column; gap: 5px; margin-bottom: 12px; }
.cs-form label {
  font-family: var(--mono); font-weight: 700;
  font-size: 10.5px; letter-spacing: 0.16em;
  text-transform: uppercase; color: var(--ink);
}
.cs-form input,
.cs-form select,
.cs-form textarea {
  width: 100%; box-sizing: border-box;
  background: var(--paper);
  border: 1px solid var(--paper-rule-2);
  border-radius: 0;
  padding: 11px 13px;
  font-family: var(--sans);
  font-size: 14px; line-height: 1.4;
  color: var(--ink);
  transition: border-color 0.15s ease;
  -webkit-appearance: none; appearance: none;
}
.cs-form input::placeholder,
.cs-form textarea::placeholder {
  color: var(--muted-light); opacity: 1;
}
.cs-form input:focus,
.cs-form select:focus,
.cs-form textarea:focus {
  outline: none; border-color: var(--red);
}
.cs-form select {
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'><path d='M1 1 L6 6 L11 1' stroke='%23161616' stroke-width='1.5' fill='none' stroke-linecap='square'/></svg>");
  background-repeat: no-repeat;
  background-position: right 13px center;
  padding-right: 34px;
}
.cs-form textarea {
  resize: vertical;
  min-height: 68px;
}
.cs-form .check {
  display: flex; align-items: flex-start; gap: 10px;
  margin: 4px 0 14px;
}
.cs-form .check input {
  width: 15px; height: 15px;
  margin: 2px 0 0; padding: 0;
  flex-shrink: 0;
  accent-color: var(--red);
}
.cs-form .check label {
  font-family: var(--sans); font-weight: 400;
  font-size: 12px; letter-spacing: 0;
  text-transform: none; color: var(--ink-soft);
  line-height: 1.45;
}
.cs-form .check a { color: var(--ink); text-decoration: underline; }
.cs-form .btn-p {
  width: 100%; justify-content: center;
  padding: 12px 16px;
  font-size: 14px;
}
.cs-form-terms {
  list-style: none; padding: 14px 0 0; margin: 14px 0 0;
  border-top: 1px solid var(--paper-rule-2);
  display: flex; flex-direction: column; gap: 5px;
}
.cs-form-terms li {
  font-family: var(--sans);
  font-size: 12px; line-height: 1.45;
  color: var(--ink-soft);
  padding-left: 16px; position: relative;
}
.cs-form-terms li::before {
  content: "\2713";
  position: absolute; left: 0; top: 1px;
  color: var(--red); font-weight: 700; font-size: 11px;
}
.cs-form-note { display: none; }

/* ═══════════════ What's in the walkthrough · matches landing-page section rhythm ═══════════════ */
.cs-expect-block { padding-top: 8px; }
.cs-expect-block .sec-tag { margin-bottom: 14px; }
.cs-expect-block h2 {
  font-family: var(--sans); font-weight: 700;
  font-size: clamp(28px, 2.6vw, 40px);
  line-height: 1.08; letter-spacing: -0.025em;
  color: var(--ink); margin: 0 0 12px;
  text-wrap: balance; max-width: 22ch;
}
.cs-expect-block h2 em {
  font-family: var(--serif); font-style: italic;
  color: var(--red); font-weight: 400;
}
.cs-expect-block .sub {
  font-family: var(--sans);
  font-size: 15px; line-height: 1.6;
  color: var(--ink-soft); margin: 0 0 22px; max-width: 60ch;
}
/* .steps is provided by service-bim-delivery.css — no overrides needed */

/* ═══════════════ Related case studies · in-column block ═══════════════ */
.cs-related-block { padding-top: 8px; }
.cs-related-head { margin-bottom: 28px; }
.cs-related-head .sec-tag { margin-bottom: 14px; }
.cs-related-head h2 {
  font-family: var(--sans); font-weight: 700;
  font-size: clamp(26px, 2.4vw, 34px);
  line-height: 1.1; letter-spacing: -0.02em;
  color: var(--ink); margin: 0;
}
.cs-related-head h2 em {
  font-family: var(--serif); font-style: italic;
  color: var(--red); font-weight: 400;
}
.cs-related-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
}
@media (max-width: 1100px) {
  .cs-related-grid { grid-template-columns: 1fr 1fr; }
  .cs-related-grid > a:nth-child(3) { grid-column: span 2; }
}
.cs-related-grid a.related-card {
  background: var(--paper);
  border: 1px solid var(--paper-rule-2);
  display: flex; flex-direction: column;
  text-decoration: none;
  color: var(--ink);
  overflow: hidden;
  transition: transform 0.25s ease, border-color 0.25s ease, box-shadow 0.25s ease;
}
.cs-related-grid a.related-card:hover {
  transform: translateY(-3px);
  border-color: var(--ink);
  box-shadow: 0 12px 28px rgba(0,0,0,0.08);
}
.cs-related-grid .related-card .ph {
  aspect-ratio: 16 / 10;
  background:
    linear-gradient(135deg, rgba(0,0,0,0.04), rgba(0,0,0,0.01)),
    var(--paper-warm);
  position: relative; overflow: hidden;
  border-bottom: 1px solid var(--paper-rule-2);
}
.cs-related-grid .related-card .ph::before,
.cs-related-grid .related-card .ph::after {
  content: ''; position: absolute; inset: 0;
  background: linear-gradient(to top right, transparent calc(50% - 0.5px), rgba(0,0,0,0.05), transparent calc(50% + 0.5px));
}
.cs-related-grid .related-card .ph::after { transform: scaleX(-1); }
.cs-related-grid .related-card .ph .tag {
  position: absolute; left: 14px; bottom: 14px;
  font-family: var(--mono); font-weight: 700;
  font-size: 10px; letter-spacing: 0.16em;
  text-transform: uppercase;
  color: #fff;
  background: rgba(0,0,0,0.6);
  backdrop-filter: blur(4px);
  padding: 5px 9px;
  border: 1px solid rgba(255,255,255,0.12);
}
.cs-related-grid .related-card .body {
  padding: 22px 24px 22px;
  display: flex; flex-direction: column;
}
.cs-related-grid .related-card .cat {
  font-family: var(--mono); font-weight: 700;
  font-size: 10.5px; letter-spacing: 0.22em;
  text-transform: uppercase; color: var(--red);
  margin-bottom: 8px;
}
.cs-related-grid .related-card h3 {
  font-family: var(--sans); font-weight: 700;
  font-size: 20px; line-height: 1.18;
  letter-spacing: -0.015em;
  color: var(--ink); margin: 0 0 8px;
}
.cs-related-grid .related-card p {
  font-family: var(--sans);
  font-size: 13px; line-height: 1.5;
  color: var(--ink-soft); margin: 0 0 14px;
}
.cs-related-grid .related-card .arr {
  margin-top: auto;
  font-family: var(--mono); font-weight: 700;
  font-size: 10.5px; letter-spacing: 0.18em;
  text-transform: uppercase; color: var(--red);
  display: inline-flex; align-items: center; gap: 8px;
}
.cs-related-grid .related-card .arr svg { width: 16px; height: 9px; }
@media (max-width: 900px) {
  .cs-related-grid { grid-template-columns: 1fr; }
}

/* ═══════════════ Responsive 2-col collapse ═══════════════ */
@media (max-width: 1100px) {
  .cs-shell-in { grid-template-columns: 1fr; }
  .cs-form-sticky { position: relative; top: auto; max-width: 480px; }
}