/* ============================================
   CASE STUDY PAGE STYLES — HTML Version
   ============================================ */

*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --cs-accent: #6B3FA0;
  --cs-accent-light: #E8DCF5;
  --cs-text: #1A1A1A;
  --cs-text-secondary: #555;
  --cs-text-muted: #888;
  --cs-bg: #FAFAF9;
  --cs-surface: #FFFFFF;
  --cs-border: #E5E5E5;
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-serif: 'Playfair Display', Georgia, serif;
}

body {
  font-family: var(--font-sans);
  color: var(--cs-text);
  background: var(--cs-bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }

/* --- Nav --- */
.cs-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: 16px 0;
  background: rgba(250, 250, 249, 0.92);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  box-shadow: 0 1px 0 var(--cs-border);
}

.cs-nav-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.cs-back {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--cs-text-secondary);
  transition: color 0.3s ease;
}

.cs-back:hover { color: var(--cs-accent); }

.cs-nav-logo {
  font-family: var(--font-serif);
  font-size: 1.5rem;
  font-weight: 600;
  color: #2B5C8A;
}

/* --- Hero Banner --- */
.cs-hero {
  margin-top: 68px;
  padding: 60px 24px 0;
}

.cs-hero-inner {
  max-width: 1100px;
  margin: 0 auto;
  border-radius: 24px;
  padding: 80px 60px;
  color: white;
  position: relative;
  overflow: hidden;
}

.cs-hero-inner.theme-purple {
  background: linear-gradient(135deg, #1A0A2E 0%, #2D1B4E 40%, #4A2D7A 100%);
}

.cs-hero-inner.theme-dark-blue {
  background: linear-gradient(135deg, #0A1628 0%, #132E4A 40%, #1A4060 100%);
}

.cs-hero-inner.theme-teal {
  background: linear-gradient(135deg, #0A2025 0%, #133A3F 40%, #1A5058 100%);
}

.cs-hero-tag {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  padding: 6px 16px;
  border: 1px solid rgba(255,255,255,0.3);
  border-radius: 100px;
  margin-bottom: 24px;
  color: rgba(255,255,255,0.8);
}

.cs-hero h1 {
  font-family: var(--font-serif);
  font-size: clamp(2.2rem, 5vw, 3.2rem);
  font-weight: 600;
  line-height: 1.15;
  margin-bottom: 16px;
}

.cs-hero .subtitle {
  font-size: 1.1rem;
  color: rgba(255,255,255,0.7);
  max-width: 600px;
  line-height: 1.6;
  margin-bottom: 40px;
}

.cs-hero-meta {
  display: flex;
  gap: 40px;
  flex-wrap: wrap;
}

.cs-hero-meta-item {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.cs-hero-meta-item .label {
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: rgba(255,255,255,0.4);
  font-weight: 600;
}

.cs-hero-meta-item .value {
  font-size: 0.95rem;
  color: rgba(255,255,255,0.9);
  font-weight: 500;
}

/* --- Content Area --- */
.cs-content {
  max-width: 760px;
  margin: 0 auto;
  padding: 60px 24px 80px;
}

.cs-section {
  margin-bottom: 56px;
}

.cs-section h2 {
  font-family: var(--font-serif);
  font-size: 1.8rem;
  font-weight: 600;
  color: var(--cs-text);
  margin-bottom: 20px;
  line-height: 1.3;
}

.cs-section h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 10px;
  color: var(--cs-text);
}

.cs-section p {
  color: var(--cs-text-secondary);
  line-height: 1.8;
  margin-bottom: 16px;
  font-size: 1rem;
}

.cs-section ul {
  color: var(--cs-text-secondary);
  line-height: 1.8;
  padding-left: 20px;
  margin-bottom: 16px;
}

.cs-section li {
  margin-bottom: 8px;
}

.cs-section strong {
  color: var(--cs-text);
}

/* --- Stats Row --- */
.cs-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin: 32px 0;
}

.cs-stat {
  background: var(--cs-surface);
  border: 1px solid var(--cs-border);
  border-radius: 16px;
  padding: 24px;
  text-align: center;
}

.cs-stat .number {
  font-family: var(--font-serif);
  font-size: 2rem;
  font-weight: 600;
  color: var(--cs-accent);
  display: block;
  margin-bottom: 4px;
}

.cs-stat .desc {
  font-size: 0.82rem;
  color: var(--cs-text-muted);
}

/* --- Issue Cards --- */
.cs-issues {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin: 24px 0;
}

.cs-issue {
  background: var(--cs-accent-light);
  border-radius: 14px;
  padding: 24px;
}

.cs-issue h4 {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--cs-accent);
  margin-bottom: 8px;
}

.cs-issue p {
  font-size: 0.85rem;
  color: var(--cs-text-secondary);
  line-height: 1.6;
  margin: 0;
}

/* --- Process Steps --- */
.cs-process {
  display: flex;
  flex-direction: column;
  gap: 24px;
  margin: 24px 0;
}

.cs-step {
  display: flex;
  gap: 20px;
  align-items: flex-start;
}

.cs-step-num {
  width: 36px;
  height: 36px;
  min-width: 36px;
  background: var(--cs-accent);
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
  font-weight: 700;
  margin-top: 2px;
}

.cs-step-content h4 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 4px;
}

.cs-step-content p {
  font-size: 0.9rem;
  color: var(--cs-text-secondary);
  margin: 0;
}

/* --- Images in content --- */
.cs-img {
  width: 100%;
  border-radius: 12px;
  margin: 28px 0;
  border: 1px solid var(--cs-border);
}

.cs-img-full {
  width: calc(100% + 120px);
  margin-left: -60px;
  border-radius: 16px;
  margin-top: 28px;
  margin-bottom: 28px;
}

/* --- Architecture Flow Diagram --- */
.cs-arch-diagram {
  background: #f8f9fb;
  background-image: radial-gradient(circle, #c8cdd6 1px, transparent 1px);
  background-size: 22px 22px;
  border: 1px solid var(--cs-border);
  border-radius: 16px;
  padding: 40px 32px;
  margin: 28px 0;
  font-family: var(--font-sans);
}

.cs-arch-row {
  display: flex;
  justify-content: center;
  gap: 24px;
  margin-bottom: 0;
}

.cs-arch-node {
  background: #fff;
  border: 1.5px solid #c8cdd6;
  border-radius: 10px;
  padding: 12px 20px;
  text-align: center;
  min-width: 160px;
}

.cs-arch-node .node-title {
  font-weight: 600;
  font-size: 0.9rem;
  color: #1a1a1a;
  display: block;
}

.cs-arch-node .node-sub {
  font-size: 0.72rem;
  color: #666;
  display: block;
  margin-top: 2px;
}

.cs-arch-connector {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 80px;
  margin: 8px 0;
  position: relative;
}

.cs-arch-connector-label {
  font-size: 0.68rem;
  color: #888;
  text-align: center;
  background: #f8f9fb;
  padding: 0 6px;
}

.cs-arch-arrow {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0;
}

.cs-arch-arrow-line {
  width: 1.5px;
  height: 18px;
  background: #aaa;
}

.cs-arch-arrow-head {
  width: 0;
  height: 0;
  border-left: 5px solid transparent;
  border-right: 5px solid transparent;
  border-top: 7px solid #aaa;
}

.cs-arch-box {
  background: #fff;
  border: 1.5px solid #c8cdd6;
  border-radius: 12px;
  padding: 20px 24px;
  margin: 0 auto;
  width: 100%;
}

.cs-arch-box.green {
  border-color: #7ac9a7;
  background: #f2fbf6;
}

.cs-arch-box.purple {
  border-color: #a78bda;
  background: #f5f0fd;
}

.cs-arch-box.orange {
  border-color: #e8a87c;
  background: #fdf6f0;
}

.cs-arch-box-title {
  font-weight: 700;
  font-size: 1rem;
  margin-bottom: 14px;
  text-align: center;
}

.cs-arch-box.green .cs-arch-box-title { color: #2a7a58; }
.cs-arch-box.purple .cs-arch-box-title { color: #5b3fa0; }
.cs-arch-box.orange .cs-arch-box-title { color: #b05c1a; }

.cs-arch-db-group {
  margin-bottom: 12px;
}

.cs-arch-db-group-label {
  font-size: 0.7rem;
  color: #777;
  font-weight: 500;
  margin-bottom: 6px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.cs-arch-db-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.cs-arch-db-tag {
  background: #fff;
  border: 1px solid #c8cdd6;
  border-radius: 6px;
  padding: 4px 10px;
  font-size: 0.72rem;
  color: #333;
}

.cs-arch-box.green .cs-arch-db-tag { border-color: #7ac9a7; }
.cs-arch-box.purple .cs-arch-db-tag { border-color: #a78bda; }

.cs-arch-subrow {
  display: flex;
  gap: 16px;
  justify-content: center;
}

.cs-arch-subrow .cs-arch-node {
  flex: 1;
  min-width: 0;
}

.cs-arch-subrow .cs-arch-node.purple {
  border-color: #a78bda;
  background: #f5f0fd;
}

.cs-arch-subrow .cs-arch-node.orange {
  border-color: #e8a87c;
  background: #fdf6f0;
}

.cs-arch-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-top: 20px;
  padding-top: 16px;
  border-top: 1px solid #ddd;
  font-size: 0.72rem;
  color: #555;
}

.cs-arch-legend-item {
  display: flex;
  align-items: center;
  gap: 7px;
}

.cs-arch-legend-dot {
  width: 12px;
  height: 12px;
  border-radius: 3px;
  border: 1.5px solid;
  flex-shrink: 0;
}

.cs-arch-figma-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.78rem;
  color: var(--cs-accent);
  border: 1px solid var(--cs-accent-light);
  border-radius: 6px;
  padding: 5px 12px;
  margin-top: 4px;
  transition: background 0.2s;
  text-decoration: none;
}

.cs-arch-figma-link:hover {
  background: var(--cs-accent-light);
}

.cs-arch-figma-link svg {
  width: 14px;
  height: 14px;
  flex-shrink: 0;
}

.cs-arch-top-connectors {
  display: flex;
  justify-content: center;
  gap: 24px;
  margin: 10px 0;
}

.cs-arch-connector-col {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.cs-arch-section-gap {
  height: 12px;
}

.cs-img-caption {
  font-size: 0.8rem;
  color: var(--cs-text-muted);
  text-align: center;
  margin-top: -16px;
  margin-bottom: 24px;
  font-style: italic;
}

/* --- Callout / Quote --- */
.cs-callout {
  background: linear-gradient(135deg, var(--cs-accent-light), #F0E8F8);
  border-left: 4px solid var(--cs-accent);
  border-radius: 0 12px 12px 0;
  padding: 20px 28px;
  margin: 28px 0;
  font-size: 0.95rem;
  color: var(--cs-text);
  line-height: 1.7;
  font-style: italic;
}

/* --- Two-column cards --- */
.cs-two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin: 24px 0;
}

.cs-card {
  background: var(--cs-surface);
  border: 1px solid var(--cs-border);
  border-radius: 16px;
  padding: 28px;
}

.cs-card h4 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 10px;
}

.cs-card p {
  font-size: 0.9rem;
  color: var(--cs-text-secondary);
  line-height: 1.6;
  margin: 0;
}

/* --- Persona Card --- */
.cs-persona {
  display: flex;
  gap: 32px;
  background: var(--cs-surface);
  border: 1px solid var(--cs-border);
  border-radius: 16px;
  padding: 32px;
  margin: 24px 0;
  align-items: center;
}

.cs-persona-img {
  width: 140px;
  height: 140px;
  border-radius: 12px;
  object-fit: cover;
  min-width: 140px;
}

.cs-persona h4 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 4px;
}

.cs-persona .role {
  font-size: 0.85rem;
  color: var(--cs-text-muted);
  margin-bottom: 12px;
}

.cs-persona p {
  font-size: 0.9rem;
  color: var(--cs-text-secondary);
  margin: 0;
  line-height: 1.6;
}

/* --- Tags --- */
.cs-tag {
  display: inline-block;
  background: var(--cs-accent-light);
  color: var(--cs-accent);
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 5px 14px;
  border-radius: 100px;
  margin-bottom: 16px;
}

/* --- Figma Embed & Prototype Links --- */
.cs-figma-embed {
  width: 100%;
  border-radius: 12px;
  border: 1px solid var(--cs-border);
  margin: 28px 0;
  overflow: hidden;
  background: var(--cs-surface);
}

.cs-figma-embed iframe {
  width: 100%;
  height: 500px;
  border: none;
  display: block;
}

.cs-prototype-links {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  margin: 28px 0;
}

.cs-proto-btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 14px 28px;
  border-radius: 12px;
  font-size: 0.9rem;
  font-weight: 600;
  transition: all 0.3s ease;
  text-decoration: none;
}

.cs-proto-btn-primary {
  background: var(--cs-accent);
  color: white;
}

.cs-proto-btn-primary:hover {
  background: #5A3390;
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(107, 63, 160, 0.25);
}

.cs-proto-btn-secondary {
  background: var(--cs-surface);
  color: var(--cs-text);
  border: 1.5px solid var(--cs-border);
}

.cs-proto-btn-secondary:hover {
  border-color: var(--cs-accent);
  color: var(--cs-accent);
  transform: translateY(-2px);
}

.cs-proto-btn svg {
  width: 18px;
  height: 18px;
}

/* --- Footer Nav --- */
.cs-footer {
  background: var(--cs-text);
  padding: 60px 24px;
}

.cs-footer-inner {
  max-width: 1100px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 24px;
}

.cs-footer-link {
  color: rgba(255,255,255,0.7);
  transition: color 0.3s ease;
}

.cs-footer-link:hover { color: white; }

.cs-footer-link .label {
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: rgba(255,255,255,0.4);
  display: block;
  margin-bottom: 4px;
}

.cs-footer-link .title {
  font-family: var(--font-serif);
  font-size: 1.2rem;
  display: block;
}

.cs-footer-home {
  color: rgba(255,255,255,0.4);
  font-size: 0.8rem;
}

.cs-footer-home:hover { color: rgba(255,255,255,0.7); }

/* --- Responsive --- */
@media (max-width: 768px) {
  .cs-hero-inner { padding: 48px 28px; }
  .cs-hero-meta { gap: 24px; }
  .cs-stats { grid-template-columns: 1fr; }
  .cs-issues { grid-template-columns: 1fr; }
  .cs-two-col { grid-template-columns: 1fr; }
  .cs-img-full { width: 100%; margin-left: 0; }
  .cs-persona { flex-direction: column; text-align: center; }
  .cs-persona-img { width: 100px; height: 100px; }
  .cs-footer-inner { flex-direction: column; text-align: center; }
}