/* ============================================================
   PRJ Clearinghouse — Design System
   ============================================================ */

:root {
  /* Color Palette */
  --clr-bg:          #0a0d14;
  --clr-bg-2:        #0f1320;
  --clr-surface:     #141928;
  --clr-surface-2:   #1c2235;
  --clr-border:      rgba(99, 130, 255, 0.12);
  --clr-border-hover:rgba(99, 130, 255, 0.35);

  --clr-accent:      #6382ff;
  --clr-accent-2:    #a78bfa;
  --clr-accent-3:    #34d399;
  --clr-accent-glow: rgba(99, 130, 255, 0.25);

  --clr-text:        #e2e8f8;
  --clr-text-2:      #8b9cc8;
  --clr-text-3:      #5a6a9a;

  /* Typography */
  --font-sans: 'Inter', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

  /* Spacing */
  --radius-sm: 6px;
  --radius:    12px;
  --radius-lg: 20px;
  --radius-xl: 28px;

  /* Transitions */
  --ease: cubic-bezier(0.4, 0, 0.2, 1);
  --dur:  220ms;
}

/* ── Reset ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font-sans);
  background: var(--clr-bg);
  color: var(--clr-text);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
}
a { color: var(--clr-accent); text-decoration: none; }
a:hover { text-decoration: underline; }
code, pre {
  font-family: var(--font-mono);
  font-size: 0.875em;
}

/* ── Layout ── */
.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ── Nav ── */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(10, 13, 20, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--clr-border);
}
.nav-inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
  height: 60px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
}
.nav-logo-icon {
  font-size: 1.4rem;
  color: var(--clr-accent);
  line-height: 1;
}
.nav-logo-text {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--clr-text);
  letter-spacing: 0.05em;
}
.nav-logo-sub {
  font-size: 0.7rem;
  color: var(--clr-text-3);
  font-weight: 400;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding-left: 8px;
  border-left: 1px solid var(--clr-border);
}
.nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
}
.nav-link {
  padding: 6px 14px;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--clr-text-2);
  transition: color var(--dur) var(--ease), background var(--dur) var(--ease);
  text-decoration: none;
}
.nav-link:hover, .nav-link.active {
  color: var(--clr-text);
  background: var(--clr-surface-2);
  text-decoration: none;
}
.nav-link-gh {
  border: 1px solid var(--clr-border);
  margin-left: 8px;
}

/* ── Hero ── */
.hero {
  position: relative;
  padding: 100px 0 80px;
  overflow: hidden;
  text-align: center;
}
.hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 60% at 50% -10%, rgba(99,130,255,0.18) 0%, transparent 70%),
    radial-gradient(ellipse 50% 40% at 80% 80%, rgba(167,139,250,0.10) 0%, transparent 60%);
  pointer-events: none;
}
.hero-badge {
  display: inline-block;
  padding: 4px 14px;
  border-radius: 999px;
  border: 1px solid rgba(99,130,255,0.4);
  background: rgba(99,130,255,0.08);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--clr-accent);
  margin-bottom: 24px;
}
.hero-title {
  font-size: clamp(2.2rem, 5vw, 3.8rem);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.02em;
  background: linear-gradient(135deg, #e2e8f8 30%, #a78bfa 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 20px;
}
.hero-sub {
  font-size: 1.05rem;
  color: var(--clr-text-2);
  max-width: 620px;
  margin: 0 auto 36px;
  line-height: 1.7;
}
.hero-sub code {
  background: var(--clr-surface-2);
  padding: 2px 6px;
  border-radius: 4px;
  color: var(--clr-accent-3);
}
.hero-search-wrap {
  position: relative;
  max-width: 520px;
  margin: 0 auto 40px;
}
.hero-search {
  width: 100%;
  padding: 14px 48px 14px 20px;
  background: var(--clr-surface);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-xl);
  color: var(--clr-text);
  font-size: 1rem;
  font-family: var(--font-sans);
  outline: none;
  transition: border-color var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}
.hero-search:focus {
  border-color: var(--clr-accent);
  box-shadow: 0 0 0 3px var(--clr-accent-glow);
}
.hero-search::placeholder { color: var(--clr-text-3); }
.hero-search-icon {
  position: absolute;
  right: 18px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 1.3rem;
  color: var(--clr-text-3);
  pointer-events: none;
}
.hero-stats {
  display: flex;
  justify-content: center;
  gap: 48px;
}
.hero-stat {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
}
.hero-stat-num {
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--clr-accent);
}
.hero-stat-label {
  font-size: 0.75rem;
  color: var(--clr-text-3);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

/* ── Filter Bar ── */
.filter-bar {
  background: var(--clr-bg-2);
  border-top: 1px solid var(--clr-border);
  border-bottom: 1px solid var(--clr-border);
  padding: 14px 0;
  position: sticky;
  top: 60px;
  z-index: 90;
}
.filter-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}
.filter-chips {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}
.chip {
  padding: 5px 14px;
  border-radius: 999px;
  border: 1px solid var(--clr-border);
  background: transparent;
  color: var(--clr-text-2);
  font-size: 0.8rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--dur) var(--ease);
  font-family: var(--font-sans);
}
.chip:hover {
  border-color: var(--clr-accent);
  color: var(--clr-accent);
}
.chip-active {
  background: var(--clr-accent);
  border-color: var(--clr-accent);
  color: #fff;
}
.sort-wrap {
  display: flex;
  align-items: center;
  gap: 8px;
}
.sort-label {
  font-size: 0.8rem;
  color: var(--clr-text-3);
}
.sort-select {
  background: var(--clr-surface);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-sm);
  color: var(--clr-text);
  font-size: 0.8rem;
  padding: 5px 10px;
  font-family: var(--font-sans);
  cursor: pointer;
  outline: none;
}

/* ── Projection Grid ── */
.main-grid-wrap {
  padding-top: 40px;
  padding-bottom: 80px;
}
.proj-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: 24px;
}
.proj-card {
  background: var(--clr-surface);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: border-color var(--dur) var(--ease), transform var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
  cursor: pointer;
  text-decoration: none;
  display: flex;
  flex-direction: column;
}
.proj-card:hover {
  border-color: var(--clr-border-hover);
  transform: translateY(-3px);
  box-shadow: 0 12px 40px rgba(0,0,0,0.4), 0 0 0 1px var(--clr-border-hover);
  text-decoration: none;
}
.proj-card-preview {
  height: 180px;
  background: var(--clr-bg);
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}
.proj-card-preview svg {
  width: 100%;
  height: 100%;
}
.proj-card-body {
  padding: 20px;
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.proj-card-tags {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}
.proj-tag {
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}
.tag-globular   { background: rgba(99,130,255,0.15); color: #6382ff; }
.tag-pseudoconical { background: rgba(167,139,250,0.15); color: #a78bfa; }
.tag-compromise { background: rgba(52,211,153,0.15); color: #34d399; }
.tag-conformal  { background: rgba(251,191,36,0.15); color: #fbbf24; }
.tag-equal-area { background: rgba(239,68,68,0.15); color: #ef4444; }
.tag-equidistant{ background: rgba(14,165,233,0.15); color: #0ea5e9; }
.proj-card-name {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--clr-text);
  line-height: 1.3;
}
.proj-card-meta {
  font-size: 0.8rem;
  color: var(--clr-text-3);
  display: flex;
  gap: 14px;
}
.proj-card-desc {
  font-size: 0.875rem;
  color: var(--clr-text-2);
  line-height: 1.6;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.proj-card-footer {
  padding: 14px 20px;
  border-top: 1px solid var(--clr-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.proj-card-formats {
  display: flex;
  gap: 4px;
}
.fmt-pill {
  padding: 2px 6px;
  border-radius: 3px;
  font-size: 0.65rem;
  font-weight: 600;
  font-family: var(--font-mono);
}
.fmt-wkt1 { background: rgba(99,130,255,0.2); color: #6382ff; }
.fmt-wkt2 { background: rgba(167,139,250,0.2); color: #a78bfa; }
.fmt-esri { background: rgba(251,191,36,0.2); color: #fbbf24; }
.fmt-prj  { background: rgba(52,211,153,0.2); color: #34d399; }
.fmt-proj { background: rgba(239,68,68,0.2); color: #ef4444; }
.fmt-json { background: rgba(14,165,233,0.2); color: #0ea5e9; }
.fmt-html { background: rgba(249,115,22,0.2); color: #f97316; }
.proj-card-arrow {
  color: var(--clr-text-3);
  font-size: 1rem;
  transition: transform var(--dur) var(--ease), color var(--dur) var(--ease);
}
.proj-card:hover .proj-card-arrow {
  transform: translateX(4px);
  color: var(--clr-accent);
}

/* ── No Results ── */
.no-results {
  text-align: center;
  padding: 60px 0;
  color: var(--clr-text-2);
  grid-column: 1 / -1;
}
.hidden { display: none !important; }
.link-btn {
  background: none;
  border: none;
  color: var(--clr-accent);
  cursor: pointer;
  font-size: inherit;
  font-family: inherit;
  text-decoration: underline;
}

/* ── About Section ── */
.about-section {
  background: var(--clr-bg-2);
  border-top: 1px solid var(--clr-border);
  padding: 80px 0;
}
.about-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: start;
}
.about-text h2 {
  font-size: 1.8rem;
  font-weight: 700;
  margin-bottom: 16px;
  color: var(--clr-text);
}
.about-text p {
  color: var(--clr-text-2);
  line-height: 1.8;
  margin-bottom: 14px;
}
.about-text code {
  background: var(--clr-surface-2);
  padding: 2px 6px;
  border-radius: 4px;
  color: var(--clr-accent-3);
}
.about-formats h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 16px;
  color: var(--clr-text);
}
.format-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.format-list li {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 0.875rem;
  color: var(--clr-text-2);
}
.fmt-badge {
  padding: 3px 8px;
  border-radius: 4px;
  font-size: 0.7rem;
  font-weight: 700;
  font-family: var(--font-mono);
  min-width: 48px;
  text-align: center;
}

/* ── Footer ── */
.site-footer {
  background: var(--clr-bg);
  border-top: 1px solid var(--clr-border);
  padding: 32px 0;
  text-align: center;
}
.footer-inner p {
  font-size: 0.85rem;
  color: var(--clr-text-3);
  margin-bottom: 4px;
}
.footer-inner a { color: var(--clr-accent); }
.footer-sub { font-size: 0.75rem !important; }

/* ── Projection Detail Page ── */
.detail-hero {
  padding: 60px 0 40px;
  border-bottom: 1px solid var(--clr-border);
  background: var(--clr-bg-2);
}
.detail-breadcrumb {
  font-size: 0.8rem;
  color: var(--clr-text-3);
  margin-bottom: 16px;
}
.detail-breadcrumb a { color: var(--clr-text-3); }
.detail-breadcrumb a:hover { color: var(--clr-accent); }
.detail-title-row {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 24px;
  flex-wrap: wrap;
}
.detail-title {
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.2;
  background: linear-gradient(135deg, #e2e8f8 30%, #a78bfa 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.detail-subtitle {
  font-size: 0.95rem;
  color: var(--clr-text-2);
  margin-top: 8px;
}
.detail-tags {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-top: 16px;
}
.detail-actions {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin-top: 16px;
}
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: var(--radius);
  font-size: 0.875rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: all var(--dur) var(--ease);
  font-family: var(--font-sans);
  text-decoration: none;
}
.btn-primary {
  background: var(--clr-accent);
  color: #fff;
}
.btn-primary:hover {
  background: #7b96ff;
  transform: translateY(-1px);
  box-shadow: 0 4px 16px rgba(99,130,255,0.4);
  text-decoration: none;
  color: #fff;
}
.btn-secondary {
  background: var(--clr-surface-2);
  color: var(--clr-text);
  border: 1px solid var(--clr-border);
}
.btn-secondary:hover {
  border-color: var(--clr-accent);
  color: var(--clr-accent);
  text-decoration: none;
}

/* ── Detail Layout ── */
.detail-layout {
  display: grid;
  grid-template-columns: 1fr 340px;
  gap: 32px;
  padding: 40px 0 80px;
  align-items: start;
}
.detail-main { min-width: 0; }
.detail-sidebar { position: sticky; top: 120px; }

/* ── D3 Preview Panel ── */
.preview-panel {
  background: var(--clr-surface);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  margin-bottom: 32px;
}
.preview-header {
  padding: 16px 20px;
  border-bottom: 1px solid var(--clr-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.preview-header h3 {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--clr-text);
}
.preview-controls {
  display: flex;
  gap: 6px;
}
.preview-btn {
  padding: 4px 10px;
  border-radius: 4px;
  border: 1px solid var(--clr-border);
  background: transparent;
  color: var(--clr-text-2);
  font-size: 0.75rem;
  cursor: pointer;
  font-family: var(--font-sans);
  transition: all var(--dur) var(--ease);
}
.preview-btn.active, .preview-btn:hover {
  background: var(--clr-accent);
  border-color: var(--clr-accent);
  color: #fff;
}
.preview-canvas {
  background: #060a12;
  display: block;
  width: 100%;
  aspect-ratio: 16/9;
}
.preview-caption {
  padding: 12px 20px;
  font-size: 0.75rem;
  color: var(--clr-text-3);
  text-align: center;
}

/* ── Info Cards ── */
.info-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-bottom: 32px;
}
.info-card {
  background: var(--clr-surface);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius);
  padding: 16px 20px;
}
.info-card-label {
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--clr-text-3);
  margin-bottom: 6px;
}
.info-card-value {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--clr-text);
}
.info-card-value.mono {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--clr-accent-3);
}

/* ── Format Tabs ── */
.format-section {
  margin-bottom: 32px;
}
.format-section h2 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 16px;
  color: var(--clr-text);
  display: flex;
  align-items: center;
  gap: 10px;
}
.format-section h2::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--clr-border);
}
.tab-bar {
  display: flex;
  gap: 2px;
  background: var(--clr-bg);
  border-radius: var(--radius) var(--radius) 0 0;
  padding: 4px;
  border: 1px solid var(--clr-border);
  border-bottom: none;
  flex-wrap: wrap;
}
.tab-btn {
  padding: 7px 14px;
  border-radius: var(--radius-sm);
  border: none;
  background: transparent;
  color: var(--clr-text-3);
  font-size: 0.78rem;
  font-weight: 600;
  cursor: pointer;
  font-family: var(--font-mono);
  transition: all var(--dur) var(--ease);
  white-space: nowrap;
}
.tab-btn.active {
  background: var(--clr-surface-2);
  color: var(--clr-text);
}
.tab-btn:hover:not(.active) {
  color: var(--clr-text-2);
}
.tab-content {
  border: 1px solid var(--clr-border);
  border-radius: 0 0 var(--radius) var(--radius);
  background: var(--clr-surface);
  overflow: hidden;
}
.tab-pane { display: none; }
.tab-pane.active { display: block; }
.code-block-wrap {
  position: relative;
}
.code-block {
  padding: 20px;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  line-height: 1.7;
  color: #c9d1e8;
  overflow-x: auto;
  white-space: pre;
  max-height: 400px;
  overflow-y: auto;
  background: #0a0e1a;
}
.code-block::-webkit-scrollbar { width: 6px; height: 6px; }
.code-block::-webkit-scrollbar-track { background: transparent; }
.code-block::-webkit-scrollbar-thumb { background: var(--clr-surface-2); border-radius: 3px; }
.copy-btn {
  position: absolute;
  top: 10px;
  right: 10px;
  padding: 5px 12px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--clr-border);
  background: var(--clr-surface-2);
  color: var(--clr-text-2);
  font-size: 0.72rem;
  font-weight: 600;
  cursor: pointer;
  font-family: var(--font-sans);
  transition: all var(--dur) var(--ease);
}
.copy-btn:hover { border-color: var(--clr-accent); color: var(--clr-accent); }
.copy-btn.copied { color: var(--clr-accent-3); border-color: var(--clr-accent-3); }
.human-readable-block {
  padding: 20px 24px;
  background: var(--clr-surface);
}
.hr-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.875rem;
}
.hr-table tr { border-bottom: 1px solid var(--clr-border); }
.hr-table tr:last-child { border-bottom: none; }
.hr-table td { padding: 10px 12px; }
.hr-table td:first-child {
  color: var(--clr-text-3);
  font-weight: 500;
  width: 40%;
  font-size: 0.8rem;
}
.hr-table td:last-child {
  color: var(--clr-text);
  font-family: var(--font-mono);
  font-size: 0.82rem;
}

/* ── Prose / Article ── */
.prose-section {
  margin-bottom: 32px;
}
.prose-section h2 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 16px;
  color: var(--clr-text);
  display: flex;
  align-items: center;
  gap: 10px;
}
.prose-section h2::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--clr-border);
}
.prose-section h3 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--clr-text);
  margin: 20px 0 8px;
}
.prose-section p {
  color: var(--clr-text-2);
  line-height: 1.8;
  margin-bottom: 14px;
  font-size: 0.9rem;
}
.prose-section ul {
  color: var(--clr-text-2);
  padding-left: 20px;
  margin-bottom: 14px;
  font-size: 0.9rem;
  line-height: 1.8;
}
.math-block {
  background: var(--clr-bg);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius);
  padding: 20px 24px;
  margin: 16px 0;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: #c9d1e8;
  line-height: 1.9;
  overflow-x: auto;
}
.math-var { color: #a78bfa; }
.math-op  { color: #6382ff; }
.math-num { color: #34d399; }

/* ── Sidebar ── */
.sidebar-card {
  background: var(--clr-surface);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-lg);
  padding: 20px;
  margin-bottom: 20px;
}
.sidebar-card h3 {
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--clr-text-3);
  margin-bottom: 14px;
}
.sidebar-dl {
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.sidebar-dl-item {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--clr-border);
}
.sidebar-dl-item:last-child { border-bottom: none; padding-bottom: 0; }
.sidebar-dl-label {
  font-size: 0.7rem;
  color: var(--clr-text-3);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}
.sidebar-dl-value {
  font-size: 0.85rem;
  color: var(--clr-text);
  font-weight: 500;
}
.download-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.download-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 14px;
  background: var(--clr-bg);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-sm);
  transition: border-color var(--dur) var(--ease);
}
.download-item:hover { border-color: var(--clr-accent); }
.download-item-name {
  font-size: 0.8rem;
  font-weight: 600;
  font-family: var(--font-mono);
  color: var(--clr-text);
}
.download-item-size {
  font-size: 0.7rem;
  color: var(--clr-text-3);
}
.download-btn {
  padding: 4px 10px;
  border-radius: 4px;
  background: var(--clr-accent);
  color: #fff;
  font-size: 0.72rem;
  font-weight: 600;
  border: none;
  cursor: pointer;
  font-family: var(--font-sans);
  transition: background var(--dur) var(--ease);
}
.download-btn:hover { background: #7b96ff; }
.ref-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.ref-list li {
  font-size: 0.78rem;
  color: var(--clr-text-2);
  line-height: 1.5;
  padding-left: 12px;
  border-left: 2px solid var(--clr-border);
}
.ref-list a { color: var(--clr-accent); }

/* ── Distortion Legend ── */
.distortion-legend {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.72rem;
  color: var(--clr-text-3);
  padding: 8px 20px;
  border-top: 1px solid var(--clr-border);
}
.legend-gradient {
  width: 80px;
  height: 8px;
  border-radius: 4px;
  background: linear-gradient(to right, #0a0e1a, #6382ff, #ef4444);
  flex-shrink: 0;
}

/* ── Responsive ── */
@media (max-width: 900px) {
  .detail-layout { grid-template-columns: 1fr; }
  .detail-sidebar { position: static; }
  .about-inner { grid-template-columns: 1fr; gap: 32px; }
  .info-grid { grid-template-columns: 1fr; }
}
@media (max-width: 600px) {
  .hero-stats { gap: 24px; }
  .nav-logo-sub { display: none; }
  .proj-grid { grid-template-columns: 1fr; }
}

/* ── Animations ── */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(16px); }
  to   { opacity: 1; transform: translateY(0); }
}
.proj-card {
  animation: fadeUp 0.4s var(--ease) both;
}
.proj-card:nth-child(1) { animation-delay: 0.05s; }
.proj-card:nth-child(2) { animation-delay: 0.10s; }
.proj-card:nth-child(3) { animation-delay: 0.15s; }
.proj-card:nth-child(4) { animation-delay: 0.20s; }
.proj-card:nth-child(5) { animation-delay: 0.25s; }
.proj-card:nth-child(6) { animation-delay: 0.30s; }

/* ── Tissot Indicatrix Colors ── */
.tissot-circle { fill: rgba(99,130,255,0.25); stroke: rgba(99,130,255,0.8); stroke-width: 0.5; }
.graticule { fill: none; stroke: rgba(255,255,255,0.08); stroke-width: 0.4; }
.sphere-fill { fill: #060d1f; }
.sphere-stroke { fill: none; stroke: rgba(99,130,255,0.5); stroke-width: 1; }
.land { fill: #1e3a5f; }
.land-stroke { fill: #1e3a5f; stroke: rgba(99,130,255,0.3); stroke-width: 0.3; }