/* ═══════════════════════════════════════════════════════════════
   CASE-STUDY.CSS — Standalone Project & Article Architecture
   Harmonized with Portfolio Design Tokens & Liquid Glass Aesthetics
   ═══════════════════════════════════════════════════════════════ */

:root {
  --cs-bg: #081014;
  --cs-surface: #0e171d;
  --cs-surface-hover: #14212a;
  --cs-border: rgba(255, 255, 255, 0.08);
  --cs-border-glow: rgba(0, 161, 155, 0.25);
  --cs-accent: #00A19B;
  --cs-accent-glow: rgba(0, 161, 155, 0.15);
  --cs-text-primary: #F0EDE4;
  --cs-text-secondary: #9BA3AF;
  --cs-text-muted: #6B7280;
  --cs-radius-sm: 8px;
  --cs-radius-md: 14px;
  --cs-radius-lg: 20px;
  --cs-font-sans: 'Space Grotesk', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --cs-font-mono: 'DM Mono', 'Fira Code', monospace;
}

@media (prefers-color-scheme: light) {
  :root {
    --cs-bg: #F5F3EF;
    --cs-surface: #FFFFFF;
    --cs-surface-hover: #EFECE6;
    --cs-border: rgba(0, 0, 0, 0.08);
    --cs-border-glow: rgba(0, 71, 67, 0.2);
    --cs-accent: #004743;
    --cs-accent-glow: rgba(0, 71, 67, 0.08);
    --cs-text-primary: #111827;
    --cs-text-secondary: #4B5563;
    --cs-text-muted: #6B7280;
  }
}

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

body {
  background-color: var(--cs-bg);
  color: var(--cs-text-primary);
  font-family: var(--cs-font-sans);
  line-height: 1.68;
  font-size: 1.05rem;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

a {
  color: var(--cs-accent);
  text-decoration: none;
  transition: opacity 0.2s ease, color 0.2s ease;
}

a:hover {
  text-decoration: underline;
}

/* Header & Breadcrumbs */
.cs-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: color-mix(in srgb, var(--cs-bg) 85%, transparent);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--cs-border);
  padding: 1rem 1.5rem;
}

.cs-header-inner {
  max-width: 960px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.cs-breadcrumb {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem;
  font-size: 0.88rem;
  color: var(--cs-text-muted);
}

.cs-breadcrumb a {
  color: var(--cs-text-secondary);
}

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

.cs-breadcrumb-sep {
  opacity: 0.5;
  user-select: none;
}

.cs-breadcrumb-current {
  color: var(--cs-text-primary);
  font-weight: 500;
}

.cs-header-home-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.45rem 0.9rem;
  font-size: 0.82rem;
  font-family: var(--cs-font-mono);
  font-weight: 600;
  color: var(--cs-text-primary);
  background: var(--cs-surface);
  border: 1px solid var(--cs-border);
  border-radius: 9999px;
  text-decoration: none !important;
  transition: all 0.25s ease;
}

.cs-header-home-btn:hover {
  border-color: var(--cs-accent);
  transform: translateY(-1px);
}

/* Container */
.cs-main {
  flex: 1;
  max-width: 960px;
  width: 100%;
  margin: 0 auto;
  padding: 3rem 1.5rem 5rem;
}

/* Hero Article Header */
.cs-hero {
  margin-bottom: 3rem;
  padding-bottom: 2.5rem;
  border-bottom: 1px solid var(--cs-border);
}

.cs-meta-row {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-bottom: 1.25rem;
}

.cs-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.25rem 0.75rem;
  border-radius: 9999px;
  font-size: 0.78rem;
  font-family: var(--cs-font-mono);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  background: var(--cs-accent-glow);
  color: var(--cs-accent);
  border: 1px solid var(--cs-border-glow);
}

.cs-period {
  font-size: 0.88rem;
  color: var(--cs-text-muted);
  font-family: var(--cs-font-mono);
}

.cs-title {
  font-size: clamp(2rem, 5vw, 3.25rem);
  line-height: 1.15;
  font-weight: 700;
  letter-spacing: -0.025em;
  margin-bottom: 1.25rem;
}

.cs-lead {
  font-size: clamp(1.1rem, 2.2vw, 1.35rem);
  line-height: 1.6;
  color: var(--cs-text-secondary);
  margin-bottom: 1.75rem;
}

/* Action CTAs */
.cs-actions {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.85rem;
  margin-top: 1.5rem;
}

.cs-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.65rem 1.25rem;
  border-radius: var(--cs-radius-sm);
  font-size: 0.9rem;
  font-weight: 600;
  text-decoration: none !important;
  transition: all 0.2s ease;
  cursor: pointer;
}

.cs-btn--primary {
  background: var(--cs-accent);
  color: #FFFFFF;
}

.cs-btn--primary:hover {
  filter: brightness(1.12);
  transform: translateY(-1px);
}

.cs-btn--outline {
  background: var(--cs-surface);
  color: var(--cs-text-primary);
  border: 1px solid var(--cs-border);
}

.cs-btn--outline:hover {
  border-color: var(--cs-accent);
  background: var(--cs-surface-hover);
  transform: translateY(-1px);
}

.cs-btn--raw {
  font-family: var(--cs-font-mono);
  font-size: 0.8rem;
  color: var(--cs-text-muted);
}

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

/* Tag Cloud */
.cs-tags {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 1.25rem;
}

.cs-tag {
  display: inline-flex;
  align-items: center;
  padding: 0.2rem 0.6rem;
  font-size: 0.76rem;
  font-family: var(--cs-font-mono);
  background: var(--cs-surface);
  border: 1px solid var(--cs-border);
  border-radius: 6px;
  color: var(--cs-text-secondary);
}

/* Case Study Content Sections */
.cs-section {
  margin-bottom: 2.75rem;
}

.cs-section h2 {
  font-size: 1.45rem;
  font-weight: 600;
  color: var(--cs-text-primary);
  margin-bottom: 0.9rem;
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.cs-section h2::before {
  content: "◆";
  font-size: 0.8rem;
  color: var(--cs-accent);
}

.cs-section p {
  color: var(--cs-text-secondary);
  font-size: 1.05rem;
  line-height: 1.75;
  margin-bottom: 1rem;
}

.cs-section ul {
  list-style: none;
  padding: 0;
  margin: 1rem 0;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.cs-section ul li {
  position: relative;
  padding-left: 1.6rem;
  color: var(--cs-text-secondary);
  line-height: 1.65;
}

.cs-section ul li::before {
  content: "→";
  position: absolute;
  left: 0;
  top: 0;
  color: var(--cs-accent);
  font-family: var(--cs-font-mono);
  font-weight: 600;
}

/* Code Snippets */
pre.cs-code {
  background: #04090c;
  border: 1px solid var(--cs-border);
  border-radius: var(--cs-radius-sm);
  padding: 1.25rem;
  overflow-x: auto;
  font-family: var(--cs-font-mono);
  font-size: 0.88rem;
  line-height: 1.55;
  color: #A7F3D0;
  margin: 1.25rem 0;
}

/* Takeaways Callout */
.cs-takeaways {
  background: var(--cs-surface);
  border: 1px solid var(--cs-border);
  border-left: 4px solid var(--cs-accent);
  border-radius: var(--cs-radius-sm);
  padding: 1.5rem;
  margin-bottom: 2.5rem;
}

.cs-takeaways-title {
  font-weight: 600;
  font-size: 1rem;
  margin-bottom: 0.75rem;
  color: var(--cs-text-primary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

/* Author Signature Card */
.cs-author-card {
  margin-top: 4rem;
  padding: 2rem;
  background: var(--cs-surface);
  border: 1px solid var(--cs-border);
  border-radius: var(--cs-radius-md);
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.cs-author-avatar {
  width: 76px;
  height: 76px;
  border-radius: 50%;
  object-fit: cover;
  border: 2px solid var(--cs-accent);
  flex-shrink: 0;
}

.cs-author-info h3 {
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 0.25rem;
}

.cs-author-info p {
  font-size: 0.92rem;
  color: var(--cs-text-secondary);
  line-height: 1.5;
}

.cs-author-links {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-top: 0.6rem;
  font-size: 0.85rem;
}

/* Footer Navigation */
.cs-footer {
  border-top: 1px solid var(--cs-border);
  padding: 2.5rem 1.5rem;
  background: var(--cs-surface);
  margin-top: auto;
}

.cs-footer-inner {
  max-width: 960px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
  font-size: 0.85rem;
  color: var(--cs-text-muted);
}

@media (max-width: 640px) {
  .cs-author-card {
    flex-direction: column;
    text-align: center;
  }
  .cs-author-links {
    justify-content: center;
  }
}