/* ============================================================
   ads.expert: Case Study Stylesheet
   Brand: Poppins · #0A0A0A · #FFFFFF · gradient #1E63CC→#42C8D2
   Light mode throughout. No client brand colors.
   ============================================================ */

:root {
  --black:       #0A0A0A;
  --white:       #FFFFFF;
  --bg-subtle:   #F4F6FB;
  --border:      rgba(0,0,0,0.08);
  --text:        #0A0A0A;
  --text-sec:    #555566;
  --text-muted:  #8F8FA0;
  --gradient:        linear-gradient(135deg, #1E63CC 0%, #42C8D2 100%);
  --gradient-r:      linear-gradient(135deg, #42C8D2 0%, #1E63CC 100%);
  /* Lighter gradient for use on dark/black backgrounds */
  --gradient-on-dark: linear-gradient(135deg, #93C5FD 0%, #67E8F9 100%);
  --blue:        #1E63CC;
  --cyan:        #42C8D2;

  --font:        'Poppins', sans-serif;
  --container:   1200px;
  --pad-x:       24px;
  --r-sm:        8px;
  --r-md:        14px;
  --r-lg:        22px;
  --r-full:      100px;
  --nav-h:       72px;
  --ease:        cubic-bezier(0.25,0.46,0.45,0.94);
  --t:           0.22s;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font);
  background: var(--white);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
img, svg { max-width: 100%; display: block; }
a { text-decoration: none; color: inherit; }
ul { list-style: none; }
h2 {
  font-size: clamp(22px, 3vw, 32px);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
  color: var(--text);
  margin-bottom: 18px;
}
p {
  font-size: 15px;
  line-height: 1.8;
  color: var(--text-sec);
  margin-bottom: 14px;
}
p:last-child { margin-bottom: 0; }

/* ===== CONTAINER ===== */
.cs-container {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 var(--pad-x);
}

/* ===== BUTTONS ===== */
.cs-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font);
  font-weight: 600;
  font-size: 14px;
  border-radius: var(--r-full);
  border: none;
  cursor: pointer;
  transition: transform var(--t) var(--ease), box-shadow var(--t);
  white-space: nowrap;
}
.cs-btn--primary {
  background: var(--gradient);
  color: #fff;
  padding: 11px 24px;
  box-shadow: 0 4px 20px rgba(30,99,204,0.28);
}
.cs-btn--primary:hover { transform: translateY(-2px); box-shadow: 0 8px 30px rgba(30,99,204,0.38); }
.cs-btn--large { padding: 15px 34px; font-size: 15px; }

/* ===== TOP NAV ===== */
.cs-nav {
  position: sticky;
  top: 0;
  z-index: 99;
  height: var(--nav-h);
  background: rgba(255,255,255,0.80);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  border-bottom: 1px solid var(--border);
}
.cs-nav__inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 var(--pad-x);
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.cs-nav__logo {
  display: flex;
  align-items: center;
  gap: 11px;
  font-size: 17px;
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--text);
}
.cs-nav__logo img { width: 34px; height: 34px; flex-shrink: 0; }
.cs-nav__right {
  display: flex;
  align-items: center;
  gap: 16px;
}
.cs-nav__back {
  display: flex;
  align-items: center;
  gap: 4px;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-muted);
  transition: color var(--t);
}
.cs-nav__back:hover { color: var(--text); }

/* ===== HERO: Light mode ===== */
.cs-hero {
  background: linear-gradient(160deg, #FFFFFF 55%, #EEF4FF 100%);
  padding: 72px 0 64px;
  border-bottom: 1px solid var(--border);
  position: relative;
  overflow: hidden;
}
.cs-hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 80% 20%, rgba(30,99,204,0.06) 0%, transparent 55%),
    radial-gradient(circle at 10% 90%, rgba(66,200,210,0.05) 0%, transparent 50%);
  pointer-events: none;
}
/* hide old noise div if it exists */
.cs-hero__noise { display: none; }

.cs-hero__inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 var(--pad-x);
  position: relative;
}
.cs-hero__tags {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 24px;
  flex-wrap: wrap;
}
.cs-tag {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.10em;
  text-transform: uppercase;
  color: var(--blue);
  background: rgba(30,99,204,0.07);
  border: 1px solid rgba(30,99,204,0.18);
  padding: 5px 12px;
  border-radius: 4px;
}
.cs-tag-sep { font-size: 12px; color: rgba(0,0,0,0.2); }
.cs-tag-sub {
  font-size: 12px;
  color: var(--text-sec);
  font-weight: 400;
}

.cs-hero__client { margin-bottom: 28px; }
.cs-hero__client-logo {
  height: 36px;   /* default for future case studies — override per logo if needed */
  width: auto;
  mix-blend-mode: multiply;
}

.cs-hero__inner {
  text-align: center;
}
.cs-hero__tags {
  justify-content: center;
}
.cs-hero__client {
  display: flex;
  justify-content: center;
}
.cs-hero__headline {
  font-size: clamp(24px, 4vw, 42px);
  font-weight: 700;
  line-height: 1.12;
  letter-spacing: -0.025em;
  color: var(--text);
  margin-bottom: 20px;
  max-width: 900px;
  margin-left: auto;
  margin-right: auto;
}
.cs-hero__desc {
  font-size: 15px;
  font-weight: 400;
  color: var(--text-sec);
  max-width: 720px;
  line-height: 1.8;
  margin: 0 auto;
}

/* ===== METRICS BAR: dark band, gradient numbers ===== */
.cs-metrics-bar { background: var(--black); }
.cs-metrics-inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 var(--pad-x);
  display: grid;
  grid-template-columns: repeat(3,1fr);
}
.cs-metric {
  padding: 24px 18px;
  border-right: 1px solid rgba(255,255,255,0.08);
  border-bottom: 1px solid rgba(255,255,255,0.06);
  display: flex;
  flex-direction: column;
  gap: 5px;
}
.cs-metric:first-child { border-left: 1px solid rgba(255,255,255,0.08); }
.cs-metric__num {
  font-size: 24px;
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1;
  background: var(--gradient-on-dark);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.cs-metric__label {
  font-size: 11px;
  font-weight: 400;
  color: rgba(255,255,255,0.80);
  line-height: 1.4;
}

/* ===== SNAPSHOT ===== */
.cs-snapshot {
  background: var(--bg-subtle);
  border-bottom: 1px solid var(--border);
  padding: 22px 0;
}
.cs-snapshot__grid {
  display: flex;
  flex-wrap: wrap;
  gap: 24px;
  align-items: center;
}
.cs-snap-item { display: flex; flex-direction: column; gap: 2px; }
.cs-snap-label {
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-muted);
}
.cs-snap-value { font-size: 13px; font-weight: 500; color: var(--text); }
.cs-divider { width: 1px; height: 28px; background: var(--border); }

/* ===== SECTIONS ===== */
.cs-section { padding: 56px 0; border-bottom: 1px solid var(--border); }
.cs-section--subtle { background: var(--bg-subtle); }

.cs-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--blue);
  margin-bottom: 12px;
}
.cs-eyebrow::before {
  content: '';
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--gradient);
  flex-shrink: 0;
}
.cs-eyebrow--light { color: rgba(255,255,255,0.45); }
.cs-eyebrow--light::before { background: rgba(255,255,255,0.35); }

/* Goal card */
.cs-goal-card {
  background: var(--bg-subtle);
  border: 1px solid var(--border);
  border-left: 3px solid var(--blue);
  border-radius: 0 var(--r-sm) var(--r-sm) 0;
  padding: 18px 22px;
  margin-top: 24px;
}
.cs-goal-label {
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 6px;
  display: block;
}
.cs-goal-text {
  font-size: 14px;
  font-weight: 600;
  color: var(--text);
  line-height: 1.6;
  margin: 0;
}

/* Challenges — 2x2 grid, matches pillar layout */
.cs-challenges { display: grid; grid-template-columns: repeat(2,1fr); gap: 12px; margin-top: 28px; }
.cs-challenge {
  display: flex;
  gap: 18px;
  align-items: flex-start;
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  padding: 22px;
}
.cs-challenge__num {
  font-size: 11px;
  font-weight: 700;
  color: var(--text-muted);
  flex-shrink: 0;
  margin-top: 3px;
  min-width: 22px;
}
.cs-challenge__title {
  font-size: 14px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 6px;
}
.cs-challenge__desc {
  font-size: 13px;
  line-height: 1.7;
  color: var(--text-sec);
  margin: 0;
}

/* Pillars */
.cs-pillars {
  display: grid;
  grid-template-columns: repeat(2,1fr);
  gap: 12px;
  margin-top: 28px;
}
.cs-pillar {
  background: var(--bg-subtle);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  padding: 22px;
}
.cs-pillar__num {
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--text-muted);
  margin-bottom: 8px;
  display: block;
}
.cs-pillar__title {
  font-size: 14px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 8px;
}
.cs-pillar__desc {
  font-size: 13px;
  line-height: 1.7;
  color: var(--text-sec);
  margin: 0;
}

/* Tech strip */
.cs-tech-strip {
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding: 14px 0;
  background: var(--bg-subtle);
}
.cs-tech-strip__inner {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  flex-wrap: wrap;
}
.cs-tech-label {
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-muted);
  white-space: nowrap;
  margin-right: 4px;
}
.cs-pill {
  font-size: 11px;
  font-weight: 600;
  color: var(--blue);
  background: rgba(30,99,204,0.06);
  border: 1px solid rgba(30,99,204,0.15);
  padding: 5px 12px;
  border-radius: var(--r-full);
  white-space: nowrap;
}
.cs-pill--logo {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--text);
  background: var(--white);
  border: 1px solid var(--border);
}
.cs-pill--logo svg { flex-shrink: 0; }

/* Wide challenge (5th item spanning 2 cols) */
.cs-challenge--wide { grid-column: span 2; }

/* Channel sub-headers inside results section */
.cs-channel-header {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 12px;
  margin-top: 8px;
}
.cs-channel-badge {
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.10em;
  text-transform: uppercase;
  color: rgba(255,255,255,0.55);
  border: 1px solid rgba(255,255,255,0.15);
  padding: 4px 10px;
  border-radius: 4px;
  white-space: nowrap;
}
.cs-channel-rule {
  flex: 1;
  height: 1px;
  background: rgba(255,255,255,0.08);
}

/* 3-col results grid (LinkedIn outbound row) */
.cs-results-grid-bot {
  display: grid;
  grid-template-columns: repeat(3,1fr);
  gap: 10px;
}

/* ===== RESULTS: dark band, ads.expert brand ===== */
.cs-results {
  background: var(--black);
  padding: 64px 0;
}
.cs-results__headline {
  color: #fff;
  margin-bottom: 6px;
  font-size: clamp(20px, 2.8vw, 30px);
}
.cs-results__sub {
  font-size: 13px;
  color: rgba(255,255,255,0.65);
  margin-bottom: 28px;
}

.cs-results-grid-top, .cs-results-grid-bot {
  display: grid;
  gap: 10px;
  margin-bottom: 10px;
}
.cs-results-grid-top { grid-template-columns: repeat(4,1fr); }

.cs-r-card {
  background: rgba(255,255,255,0.04);
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: var(--r-md);
  padding: 18px 16px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.cs-r-card--hl {
  background: rgba(30,99,204,0.12);
  border-color: rgba(30,99,204,0.28);
}
.cs-r-card--green {
  background: rgba(66,200,210,0.10);
  border-color: rgba(66,200,210,0.25);
}
.cs-r-num {
  font-size: 26px;
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1;
  background: var(--gradient-on-dark);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.cs-r-num--green {
  background: linear-gradient(135deg, #67E8F9 0%, #A5F3FC 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.cs-r-label { font-size: 11px; color: rgba(255,255,255,0.82); line-height: 1.45; }

.cs-roas-callout {
  background: var(--gradient);
  border-radius: var(--r-md);
  padding: 28px 32px;
  margin-top: 12px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}
.cs-roas-num {
  font-size: 52px;
  font-weight: 800;
  color: #fff;
  letter-spacing: -0.04em;
  line-height: 1;
}
.cs-roas-sub {
  font-size: 13px;
  font-weight: 500;
  color: rgba(255,255,255,0.7);
  margin-top: 5px;
  display: block;
}
.cs-roas-desc {
  font-size: 14px;
  font-weight: 400;
  color: rgba(255,255,255,0.85);
  max-width: 340px;
  line-height: 1.65;
  text-align: right;
  margin: 0;
}

/* ===== TESTIMONIAL ===== */
.cs-testimonial-section {
  padding: 64px 0;
  border-bottom: 1px solid var(--border);
}
.cs-testimonial-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  padding: 40px;
  margin-top: 20px;
  box-shadow: 0 4px 32px rgba(0,0,0,0.06);
}
.cs-testimonial-card__stars {
  font-size: 21px;
  letter-spacing: 3px;
  background: linear-gradient(90deg, #D97706 0%, #FBBF24 30%, #FDE68A 50%, #FBBF24 70%, #D97706 100%);
  background-size: 200% auto;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: star-shimmer 2.8s linear infinite;
  margin-bottom: 22px;
  display: block;
}
@keyframes star-shimmer {
  0%   { background-position: 0% center; }
  100% { background-position: 200% center; }
}
.cs-testimonial-card__quote {
  font-size: 16px;
  line-height: 1.85;
  color: var(--text-sec);
  font-style: normal;
  margin-bottom: 28px;
  border: none;
  padding: 0;
  position: relative;
}
.quote-extra {
  display: none;
}
.quote-extra.is-visible {
  display: inline;
}
.see-more-btn {
  background: none;
  border: none;
  cursor: pointer;
  font-family: var(--font);
  font-size: 14px;
  font-weight: 600;
  color: var(--blue);
  padding: 0;
  margin-left: 2px;
  transition: opacity var(--t);
}
.see-more-btn:hover { opacity: 0.75; }

/* Author row */
.cs-testimonial-card__author {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 22px;
  border-top: 1px solid var(--border);
  color: inherit;
  transition: opacity 0.2s;
}
.cs-testimonial-card__author-left {
  display: flex;
  align-items: center;
  gap: 14px;
}
.cs-avatar {
  width: 52px;
  height: 52px;
  border-radius: 50%;
  background: var(--gradient);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 15px;
  font-weight: 700;
  color: #fff;
  flex-shrink: 0;
  letter-spacing: 0.5px;
  user-select: none;
}
.cs-avatar--photo {
  object-fit: cover;
  object-position: center top;
  border: 2px solid var(--border);
}
.cs-testimonial-card__author-info { display: flex; flex-direction: column; gap: 3px; }
.cs-testimonial-card__name {
  font-size: 15px;
  font-weight: 600;
  color: var(--text);
}
.cs-testimonial-card__role {
  font-size: 13px;
  color: var(--text-muted);
}
.cs-testimonial-card__linkedin {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  font-weight: 500;
  color: #0A66C2;
  transition: opacity var(--t);
  flex-shrink: 0;
}
.cs-testimonial-card__linkedin:hover { opacity: 0.75; }

/* ===== CTA ===== */
.cs-cta {
  padding: 80px 0;
  background: var(--bg-subtle);
  border-top: 1px solid var(--border);
}
.cs-cta__inner {
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
}
.cs-cta__headline {
  color: var(--text);
  font-size: clamp(22px, 3vw, 34px);
}
.cs-cta__sub {
  font-size: 16px;
  color: var(--text-sec);
  max-width: 460px;
  text-align: center;
  margin: 0;
}

/* ===== FOOTER ===== */
.cs-footer {
  padding: 28px 0;
  background: var(--white);
  border-top: 1px solid var(--border);
}
.cs-footer__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.cs-footer__legal { font-size: 12px; color: var(--text-muted); }

/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
  .cs-metrics-inner { grid-template-columns: repeat(3,1fr); }
  .cs-pillars { grid-template-columns: 1fr; }
  .cs-challenges { grid-template-columns: 1fr; }
  .cs-challenge--wide { grid-column: span 1; }
  .cs-results-grid-top { grid-template-columns: repeat(2,1fr); }
  .cs-results-grid-bot { grid-template-columns: repeat(2,1fr); }
  .cs-roas-callout { flex-direction: column; align-items: flex-start; }
  .cs-roas-desc { text-align: left; max-width: 100%; }
  .cs-snapshot__grid { gap: 14px; }
  .cs-divider { display: none; }
  .cs-nav__right .cs-nav__back { display: none; }
  .cs-testimonial-card { padding: 28px 22px; }
  .cs-testimonial-card__author { flex-direction: column; align-items: flex-start; gap: 14px; }
  .cs-footer__inner { flex-direction: column; gap: 12px; text-align: center; }
}

@media (max-width: 480px) {
  .cs-metrics-inner { grid-template-columns: repeat(3,1fr); }
  .cs-results-grid-top { grid-template-columns: 1fr 1fr; }
  .cs-hero { padding: 52px 0 48px; }
  .cs-section { padding: 44px 0; }
  .cs-testimonial-section { padding: 44px 0; }
}