/* ════════════════════════════════════════════════════════════════
   CHOCO Technology — list-case.css  |  v1.0  |  2026-05-02
   Page: Case Studies list  (/Cases/)
   Source: 静态页面/case-studies.html  <style> 块
   ────────────────────────────────────────────────────────────────
   ✅ INCLUDED : :root tokens · reset · case-hero · stats-strip
                 gallery · featured-case · case-group · case-card
                 tabs-wrap · tabs · fade-up · responsive (page only)
   ❌ EXCLUDED : .topbar .nav .mobile-menu  → choco-header.css
                 .cta-band .footer .float-wa .back-top → choco-header.css
════════════════════════════════════════════════════════════════ */

/* ── Design tokens (page-level, mirrors CHOCO_DESIGN_SPEC.md) ── */
:root {
  --red:        #D42B2B;
  --red-dark:   #B52020;
  --red-light:  #FBF0F0;
  --blue:       #1539A0;
  --dark:       #111111;
  --dark2:      #1E1E1E;
  --mid:        #5A5A5A;
  --muted:      #8A8A8A;
  --border:     #E4E4E4;
  --light:      #F6F6F6;
  --white:      #FFFFFF;
  --font:       'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --max:        1400px;
  --dn-deepest: #080e1c;
  --dn-deep:    #0D1526;
  --dn-navy:    #0B1220;
  --dn-mid:     #111827;
}

/* ── Global reset (page-scoped baseline) ────────────────────── */
*, *::before, *::after { margin:0; padding:0; box-sizing:border-box; }
html { scroll-behavior:smooth; }
body {
  font-family:var(--font);
  background:var(--dn-deepest);
  color:#fff;
  line-height:1.65;
  overflow-x:hidden;
  -webkit-font-smoothing:antialiased;
}
a  { text-decoration:none; color:inherit; }
ul { list-style:none; }
img { display:block; max-width:100%; }
button { font-family:var(--font); cursor:pointer; border:none; background:none; }

/* ══════════════════════════════════════════════════════════════
   CASE HERO
══════════════════════════════════════════════════════════════ */
.case-hero {
  position:relative;
  overflow:hidden;
  background:var(--dn-deep);
  min-height:440px;
  display:flex; align-items:center;
  border-bottom:3px solid var(--red);
}

/* Default background image; overridden by inline style when cat_background is set */
.case-hero-bg {
  position:absolute; inset:0;
  background-image:url('../picture/case-hero-bg.jpg');
  background-size:cover;
  background-position:center;
  opacity:.20;
  filter:saturate(.7) contrast(1.05);
}

.case-hero::after {
  content:''; position:absolute; inset:0;
  background:
    linear-gradient(90deg, rgba(11,18,32,.96) 0%, rgba(11,18,32,.55) 65%, rgba(11,18,32,.20) 100%),
    radial-gradient(ellipse 70% 80% at 12% 60%, rgba(21,57,160,.30) 0%, transparent 55%),
    radial-gradient(ellipse 60% 70% at 92% 10%, rgba(212,43,43,.20) 0%, transparent 55%);
  pointer-events:none;
}

.case-hero::before {
  content:''; position:absolute; inset:0;
  background-image:
    linear-gradient(rgba(255,255,255,.026) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.026) 1px, transparent 1px);
  background-size:48px 48px;
  pointer-events:none; z-index:0;
}

.case-hero-inner {
  position:relative; z-index:1;
  width:100%; max-width:var(--max);
  margin:0 auto; padding:80px 48px 64px;
}

.hero-eyebrow {
  display:inline-flex; align-items:center; gap:12px;
  font-size:11px; font-weight:700; letter-spacing:.18em; text-transform:uppercase;
  color:var(--red); margin-bottom:20px;
}
.hero-eyebrow::before { content:''; display:block; width:32px; height:1.5px; background:var(--red); }

.hero-h1 {
  font-size:clamp(40px, 5.6vw, 68px);
  font-weight:800; line-height:1.05; letter-spacing:-.035em;
  color:#fff; margin-bottom:18px; max-width:880px;
}
.hero-h1 span { color:var(--red); }

.hero-sub {
  font-size:16px; color:rgba(255,255,255,.66);
  max-width:620px; margin-bottom:28px; line-height:1.72;
}

.case-breadcrumb {
  display:flex; align-items:center; gap:8px;
  font-size:13px; color:rgba(255,255,255,.42);
}
.case-breadcrumb a   { color:rgba(255,255,255,.42); transition:color .2s; }
.case-breadcrumb a:hover { color:rgba(255,255,255,.85); }
.case-breadcrumb .sep { color:var(--red); font-size:10px; }
.case-breadcrumb .cur { color:rgba(255,255,255,.78); }

/* ══════════════════════════════════════════════════════════════
   STATS STRIP
══════════════════════════════════════════════════════════════ */
.stats-strip {
  background:var(--dn-navy);
  border-bottom:1px solid rgba(255,255,255,.07);
  background-image:radial-gradient(ellipse 50% 80% at 50% 50%, rgba(21,57,160,.10) 0%, transparent 70%);
}
.stats-strip-inner {
  max-width:var(--max); margin:0 auto;
  display:grid; grid-template-columns:repeat(4, 1fr);
  border-left:1px solid rgba(255,255,255,.07);
}
.stat-card {
  padding:36px 32px;
  border-right:1px solid rgba(255,255,255,.07);
  text-align:center;
  transition:background .25s;
}
.stat-card:hover { background:rgba(255,255,255,.03); }
.stat-num {
  font-size:clamp(28px, 3.5vw, 40px);
  font-weight:800; line-height:1; letter-spacing:-.02em;
  color:#fff; margin-bottom:8px;
}
.stat-num .suffix { color:var(--red); }
.stat-label {
  font-size:11.5px; font-weight:700; letter-spacing:.14em; text-transform:uppercase;
  color:rgba(255,255,255,.5);
}

/* ══════════════════════════════════════════════════════════════
   MAIN GALLERY (col-9 cases + col-3 sticky tabs)
══════════════════════════════════════════════════════════════ */
.gallery {
  background:var(--dn-mid);
  padding:80px 0 96px;
  position:relative;
  background-image:
    radial-gradient(ellipse 60% 50% at 88% 8%, rgba(21,57,160,.16) 0%, transparent 55%),
    radial-gradient(ellipse 55% 40% at 8% 92%, rgba(212,43,43,.10) 0%, transparent 55%);
}
.gallery-inner {
  max-width:var(--max); margin:0 auto; padding:0 48px;
  display:grid; grid-template-columns:1fr 240px; gap:48px;
  align-items:start;
}

/* ── Common eyebrow & headings ───────────────────────────────── */
.eyebrow {
  display:inline-flex; align-items:center; gap:10px;
  font-size:11px; font-weight:700; letter-spacing:.16em; text-transform:uppercase;
  color:var(--red); margin-bottom:14px;
}
.eyebrow::before { content:''; width:22px; height:2px; background:var(--red); display:block; flex-shrink:0; }
.eyebrow.center { justify-content:center; }
.eyebrow.center::before { display:none; }

.group-h2 {
  font-size:clamp(24px, 2.6vw, 32px);
  font-weight:800; line-height:1.2; letter-spacing:-.02em;
  color:#fff; margin-bottom:6px;
}
.group-sub {
  font-size:14.5px; color:rgba(255,255,255,.5);
  margin-bottom:22px; line-height:1.65;
}

/* ══════════════════════════════════════════════════════════════
   FEATURED CASE (large hero card)
══════════════════════════════════════════════════════════════ */
.featured-case {
  position:relative;
  margin-bottom:64px;
  border-radius:6px;
  overflow:hidden;
  background:rgba(255,255,255,.04);
  border:1px solid rgba(255,255,255,.10);
  backdrop-filter:blur(8px);
  -webkit-backdrop-filter:blur(8px);
  transition:transform .3s, box-shadow .3s, border-color .3s;
}
.featured-case:hover {
  transform:translateY(-3px);
  box-shadow:
    0 0 0 1px rgba(212,43,43,.35),
    0 16px 50px rgba(0,0,0,.55),
    0 0 30px rgba(21,57,160,.16);
}

.featured-grid {
  display:grid; grid-template-columns:1.1fr 1fr; gap:0;
}

.featured-img {
  position:relative;
  aspect-ratio:16/10;
  overflow:hidden;
  background:#080e1c;
}
.featured-img img {
  width:100%; height:100%; object-fit:cover;
  transition:transform .6s ease;
}
.featured-case:hover .featured-img img { transform:scale(1.04); }
.featured-img::after {
  content:''; position:absolute; inset:auto 0 0 0; height:50%;
  background:linear-gradient(180deg, transparent 0%, rgba(8,14,28,.6) 100%);
  pointer-events:none;
}

.featured-tag {
  position:absolute; top:18px; left:18px; z-index:2;
  padding:6px 12px;
  background:var(--red); color:#fff;
  font-size:10.5px; font-weight:700; letter-spacing:.12em; text-transform:uppercase;
  border-radius:3px;
  box-shadow:0 4px 16px rgba(212,43,43,.45);
}

.featured-content {
  padding:40px 36px;
  display:flex; flex-direction:column; justify-content:center;
}
.featured-eyebrow {
  font-size:11px; font-weight:700; letter-spacing:.14em; text-transform:uppercase;
  color:var(--red); margin-bottom:14px;
}
.featured-title {
  font-size:clamp(22px, 2.4vw, 30px);
  font-weight:800; line-height:1.2; color:#fff;
  margin-bottom:14px; letter-spacing:-.015em;
}
.featured-desc {
  font-size:14.5px; color:rgba(255,255,255,.62); line-height:1.75;
  margin-bottom:22px;
}

.featured-meta {
  display:flex; flex-wrap:wrap; gap:18px;
  padding:18px 0;
  border-top:1px solid rgba(255,255,255,.08);
  border-bottom:1px solid rgba(255,255,255,.08);
  margin-bottom:22px;
}
.featured-meta-item .k {
  display:block;
  font-size:10.5px; font-weight:700; letter-spacing:.12em; text-transform:uppercase;
  color:rgba(255,255,255,.4); margin-bottom:4px;
}
.featured-meta-item .v {
  font-size:14.5px; font-weight:600; color:#fff;
}

.featured-link {
  display:inline-flex; align-items:center; gap:8px;
  font-size:12.5px; font-weight:700; letter-spacing:.10em; text-transform:uppercase;
  color:var(--red);
  transition:color .2s, gap .2s;
  align-self:flex-start;
}
.featured-link:hover { color:#fff; gap:14px; }
.featured-link svg { transition:transform .25s; }
.featured-link:hover svg { transform:translateX(3px); }

/* ══════════════════════════════════════════════════════════════
   CASE GROUP (per market section)
══════════════════════════════════════════════════════════════ */
.case-group {
  scroll-margin-top:120px;
  margin-bottom:60px;
}
.case-group:last-of-type { margin-bottom:0; }

.case-group-head {
  display:flex; align-items:flex-end; justify-content:space-between; flex-wrap:wrap;
  gap:14px;
  margin-bottom:24px;
  padding-bottom:18px;
  border-bottom:1px solid rgba(255,255,255,.10);
}
.case-group-count {
  font-size:11.5px; font-weight:700; letter-spacing:.14em; text-transform:uppercase;
  color:rgba(255,255,255,.42);
  padding-bottom:4px;
}
.case-group-count strong { color:var(--red); }

/* ══════════════════════════════════════════════════════════════
   CASES GRID — 2-col card grid
══════════════════════════════════════════════════════════════ */
.cases-grid {
  display:grid;
  grid-template-columns:repeat(2, 1fr);
  gap:20px;
}

.case-card {
  position:relative;
  background:rgba(255,255,255,.04);
  border:1px solid rgba(255,255,255,.08);
  backdrop-filter:blur(8px);
  -webkit-backdrop-filter:blur(8px);
  border-radius:4px;
  overflow:hidden;
  display:flex; flex-direction:column;
  transition:transform .25s, border-color .25s, background .25s, box-shadow .25s;
}
.case-card:hover {
  transform:translateY(-3px);
  background:rgba(255,255,255,.07);
  box-shadow:
    0 0 0 1px rgba(212,43,43,.30),
    0 16px 40px rgba(0,0,0,.55),
    0 0 24px rgba(21,57,160,.16);
}

.case-card-img {
  position:relative;
  aspect-ratio:16/10;
  overflow:hidden;
  background:#080e1c;
}
.case-card-img img {
  width:100%; height:100%; object-fit:cover;
  transition:transform .5s ease;
}
.case-card:hover .case-card-img img { transform:scale(1.05); }
.case-card-img::after {
  content:''; position:absolute; inset:auto 0 0 0; height:50%;
  background:linear-gradient(180deg, transparent 0%, rgba(8,14,28,.5) 100%);
}

.case-card-pitch {
  position:absolute; top:14px; left:14px; z-index:2;
  padding:5px 10px;
  background:rgba(11,18,32,.85);
  border:1px solid rgba(255,255,255,.18);
  border-radius:3px;
  font-size:10.5px; font-weight:700; letter-spacing:.10em; text-transform:uppercase;
  color:#fff;
  backdrop-filter:blur(6px);
}
.case-card-pitch.red { background:rgba(212,43,43,.92); border-color:transparent; }

.case-card-content {
  padding:22px 22px 24px;
  display:flex; flex-direction:column; flex:1;
}
.case-card-meta {
  display:flex; align-items:center; gap:8px;
  font-size:11px; font-weight:600; letter-spacing:.06em; text-transform:uppercase;
  color:rgba(255,255,255,.4);
  margin-bottom:10px;
}
.case-card-meta .dot {
  width:4px; height:4px; border-radius:50%;
  background:var(--red); flex-shrink:0;
}
.case-card-title {
  font-size:16.5px; font-weight:700; color:#fff; line-height:1.35;
  margin-bottom:8px; letter-spacing:-.005em;
}
.case-card-desc {
  font-size:13.5px; color:rgba(255,255,255,.55); line-height:1.65;
  margin-bottom:14px; flex:1;
}
.case-card-foot {
  display:flex; align-items:center; justify-content:space-between;
  padding-top:14px;
  border-top:1px solid rgba(255,255,255,.07);
  font-size:12px;
}
.case-card-area { color:rgba(255,255,255,.55); font-weight:600; }
.case-card-area span { color:rgba(255,255,255,.35); font-weight:500; margin-right:4px; }
.case-card-link {
  display:inline-flex; align-items:center; gap:5px;
  color:var(--red); font-weight:700; letter-spacing:.04em; text-transform:uppercase;
  font-size:11px;
  transition:gap .2s, color .2s;
}
.case-card-link:hover { gap:10px; color:#fff; }

/* ══════════════════════════════════════════════════════════════
   STICKY TABS (right col-3)
══════════════════════════════════════════════════════════════ */
.tabs-wrap {
  position:sticky; top:104px;
}
.tabs-title {
  font-size:10.5px; font-weight:700; letter-spacing:.14em; text-transform:uppercase;
  color:rgba(255,255,255,.4); margin-bottom:16px;
  padding:0 14px;
}
.tabs {
  display:flex; flex-direction:column;
  background:rgba(255,255,255,.03);
  border:1px solid rgba(255,255,255,.08);
  border-radius:6px;
  padding:8px;
  backdrop-filter:blur(8px);
  -webkit-backdrop-filter:blur(8px);
}
.tab {
  display:flex; align-items:center; justify-content:space-between; gap:8px;
  padding:11px 14px;
  background:transparent;
  border:none;
  font-size:13px; font-weight:600; color:rgba(255,255,255,.62);
  text-align:left;
  border-radius:3px;
  cursor:pointer;
  transition:background .2s, color .2s, padding-left .2s;
  font-family:var(--font);
  width:100%;
}
.tab:hover { background:rgba(255,255,255,.04); color:#fff; padding-left:18px; }
.tab.on {
  background:rgba(212,43,43,.10);
  color:#fff;
  box-shadow:inset 3px 0 0 var(--red);
  padding-left:18px;
}
.tab .tab-count {
  font-size:11px; font-weight:700; letter-spacing:.06em;
  color:rgba(255,255,255,.32);
  background:rgba(255,255,255,.06);
  padding:2px 7px;
  border-radius:10px;
  min-width:24px; text-align:center;
}
.tab.on .tab-count { color:var(--red); background:rgba(212,43,43,.15); }

.tabs-cta {
  margin-top:18px;
  background:rgba(255,255,255,.04);
  border:1px solid rgba(255,255,255,.10);
  border-top:3px solid var(--red);
  border-radius:6px;
  padding:20px;
}
.tabs-cta h4 {
  font-size:14px; font-weight:700; color:#fff;
  margin-bottom:8px;
}
.tabs-cta p {
  font-size:12.5px; color:rgba(255,255,255,.55); line-height:1.6;
  margin-bottom:14px;
}
.tabs-cta a {
  display:block; text-align:center;
  padding:11px;
  background:var(--red); color:#fff;
  font-size:11.5px; font-weight:700; letter-spacing:.10em; text-transform:uppercase;
  border-radius:3px;
  transition:background .2s, transform .15s, box-shadow .2s;
  box-shadow:0 4px 14px rgba(212,43,43,.30);
}
.tabs-cta a:hover {
  background:var(--red-dark);
  transform:translateY(-2px);
  box-shadow:0 8px 22px rgba(212,43,43,.45);
}

/* ══════════════════════════════════════════════════════════════
   SCROLL ANIMATIONS
══════════════════════════════════════════════════════════════ */
.fade-up { opacity:0; transform:translateY(20px); transition:opacity .55s ease, transform .55s ease; }
.fade-up.visible { opacity:1; transform:none; }
.d1 { transition-delay:.08s; }
.d2 { transition-delay:.16s; }
.d3 { transition-delay:.24s; }
.d4 { transition-delay:.32s; }

/* ══════════════════════════════════════════════════════════════
   RESPONSIVE
══════════════════════════════════════════════════════════════ */
@media (max-width:1100px) {
  .stats-strip-inner { grid-template-columns:repeat(2,1fr); }
  .gallery-inner     { grid-template-columns:1fr; gap:32px; }
  .tabs-wrap         { position:static; order:-1; }
  .tabs              { flex-direction:row; flex-wrap:wrap; padding:6px; }
  .tab               { flex:1 1 auto; justify-content:center; }
  .tab.on            { box-shadow:inset 0 -3px 0 var(--red); padding-left:14px; }
  .tabs-title        { display:none; }
  .tabs-cta          { display:none; }
  .featured-grid     { grid-template-columns:1fr; }
  .featured-content  { padding:28px 24px; }
}

@media (max-width:768px) {
  .case-hero-inner   { padding:60px 20px 50px; }
  .gallery-inner     { padding-left:20px; padding-right:20px; }
  .gallery           { padding:60px 0 76px; }
  .cases-grid        { grid-template-columns:1fr; }
}

@media (max-width:480px) {
  .stats-strip-inner { grid-template-columns:1fr; }
}