/* ============================================================
   HOSA — Academic Research Site Stylesheet
   ============================================================ */

/* --- Reset & Base --- */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  /* Background */
  --bg-root: #080a12;
  --bg-primary: #0c0f1a;
  --bg-secondary: #12162a;
  --bg-card: #161b30;
  --bg-card-hover: #1b2138;
  --bg-code: #0d1017;

  /* Accent — refined teal-green */
  --accent: #4ec9a0;
  --accent-dim: #3da882;
  --accent-subtle: rgba(78, 201, 160, 0.08);
  --accent-border: rgba(78, 201, 160, 0.18);

  /* Text */
  --text-primary: #dce0ea;
  --text-secondary: #8891a8;
  --text-tertiary: #5c6478;
  --text-accent: var(--accent);

  /* Borders */
  --border: #1e2540;
  --border-hover: #2c3558;

  /* Severity colors */
  --level-0: #4ec9a0;
  --level-1: #5ba8d4;
  --level-2: #d4a853;
  --level-3: #d48a4e;
  --level-4: #d46a5e;
  --level-5: #c94e4e;

  /* Layout */
  --max-width: 1080px;
  --narrow-width: 760px;
  --nav-height: 60px;

  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-serif: 'Source Serif 4', 'Georgia', 'Times New Roman', serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Consolas', monospace;

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 200ms ease;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
  color: var(--text-primary);
  background-color: var(--bg-root);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--accent-dim);
}

code {
  font-family: var(--font-mono);
  font-size: 0.85em;
  background: var(--bg-code);
  padding: 0.15em 0.4em;
  border-radius: 3px;
  border: 1px solid var(--border);
}

strong {
  font-weight: 600;
}

/* --- Utilities --- */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

.container-narrow {
  max-width: var(--narrow-width);
}

.text-accent { color: var(--accent); }
.text-secondary { color: var(--text-secondary); }

/* --- Navigation --- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: rgba(8, 10, 18, 0.9);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  z-index: 1000;
  display: flex;
  align-items: center;
}

.nav .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--text-primary);
  letter-spacing: -0.01em;
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 26px;
  height: 26px;
  background: var(--accent);
  color: var(--bg-root);
  font-size: 0.75rem;
  font-weight: 800;
  border-radius: 5px;
  letter-spacing: 0;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
  list-style: none;
}

.nav-links a {
  color: var(--text-secondary);
  font-size: 0.84rem;
  font-weight: 500;
  padding: 6px 14px;
  border-radius: 6px;
  transition: all var(--transition-fast);
}

.nav-links a:hover {
  color: var(--text-primary);
  background: var(--bg-card);
}

.nav-links .active a {
  color: var(--accent);
}

.nav-right {
  display: flex;
  align-items: center;
  gap: 12px;
}

.lang-switch {
  display: flex;
  align-items: center;
  gap: 2px;
  background: var(--bg-secondary);
  border-radius: 5px;
  padding: 2px;
  border: 1px solid var(--border);
}

.lang-switch a {
  font-size: 0.72rem;
  font-weight: 600;
  padding: 3px 9px;
  border-radius: 3px;
  color: var(--text-tertiary);
  transition: all var(--transition-fast);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.lang-switch a:hover { color: var(--text-secondary); }
.lang-switch a.active { color: var(--text-primary); background: var(--bg-card); }

.nav-github {
  display: flex;
  align-items: center;
  color: var(--text-secondary);
  transition: color var(--transition-fast);
}
.nav-github:hover { color: var(--text-primary); }
.nav-github svg { width: 20px; height: 20px; fill: currentColor; }

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  color: var(--text-secondary);
}
.nav-toggle span {
  display: block;
  width: 18px;
  height: 2px;
  background: currentColor;
  margin: 4px 0;
  border-radius: 1px;
}

/* --- Hero --- */
.hero {
  padding: 140px 0 80px;
  text-align: center;
  border-bottom: 1px solid var(--border);
}

.hero-context {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  margin-bottom: 28px;
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--text-secondary);
}

.hero-institution {
  color: var(--accent);
  font-weight: 600;
}

.hero-sep {
  color: var(--text-tertiary);
}

.hero h1 {
  font-family: var(--font-serif);
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
  margin-bottom: 8px;
  color: var(--text-primary);
}

.hero-acronym {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--accent);
  letter-spacing: 0.2em;
  margin-bottom: 24px;
}

.hero-subtitle {
  font-size: 1.05rem;
  color: var(--text-secondary);
  max-width: 620px;
  margin: 0 auto 36px;
  line-height: 1.7;
}

.hero-meta {
  display: flex;
  justify-content: center;
  gap: 36px;
  margin-bottom: 36px;
  flex-wrap: wrap;
}

.hero-meta > div {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
}

.meta-label {
  font-size: 0.68rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-tertiary);
}

.meta-value {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-primary);
}

.hero-ctas {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 24px;
  font-size: 0.85rem;
  font-weight: 600;
  border-radius: 6px;
  border: none;
  cursor: pointer;
  transition: all var(--transition-base);
  text-decoration: none;
  font-family: var(--font-sans);
}

.btn-primary {
  background: var(--accent);
  color: var(--bg-root);
}
.btn-primary:hover {
  background: var(--accent-dim);
  color: var(--bg-root);
  transform: translateY(-1px);
}

.btn-secondary {
  background: var(--bg-card);
  color: var(--text-primary);
  border: 1px solid var(--border);
}
.btn-secondary:hover {
  background: var(--bg-card-hover);
  color: var(--text-primary);
  border-color: var(--border-hover);
  transform: translateY(-1px);
}

.btn svg { width: 14px; height: 14px; fill: currentColor; }

/* --- Sections --- */
.section {
  padding: 88px 0;
}

.section-alt {
  background: var(--bg-primary);
}

.section-header {
  text-align: center;
  margin-bottom: 56px;
}

.section-label {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--accent);
  margin-bottom: 14px;
}

.section-title {
  font-family: var(--font-serif);
  font-size: clamp(1.6rem, 3.5vw, 2.2rem);
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.015em;
  margin-bottom: 14px;
}

.section-desc {
  font-size: 0.95rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto;
  line-height: 1.7;
}

/* --- Abstract --- */
.abstract-block {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 36px 40px;
}

.abstract-block p {
  font-size: 0.92rem;
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 14px;
}

.abstract-block p:last-of-type {
  margin-bottom: 20px;
}

.abstract-keywords {
  border-top: 1px solid var(--border);
  padding-top: 16px;
  font-size: 0.82rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.kw-label {
  font-weight: 700;
  color: var(--text-primary);
}

/* --- Feature Cards --- */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 16px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 28px 24px;
  transition: border-color var(--transition-base);
  position: relative;
}

.feature-card:hover {
  border-color: var(--border-hover);
}

.feature-number {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 12px;
  letter-spacing: 0.02em;
}

.feature-card h3 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 8px;
  letter-spacing: -0.01em;
}

.feature-card p {
  color: var(--text-secondary);
  font-size: 0.87rem;
  line-height: 1.65;
}

/* --- Comparison Section --- */
.comparison-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-bottom: 48px;
}

.comparison-card {
  padding: 28px 24px;
  border-radius: 10px;
  border: 1px solid var(--border);
}

.comparison-card.without {
  background: rgba(196, 78, 78, 0.03);
  border-color: rgba(196, 78, 78, 0.15);
}

.comparison-card.with {
  background: var(--accent-subtle);
  border-color: var(--accent-border);
}

.comparison-card h3 {
  font-size: 0.92rem;
  font-weight: 700;
  margin-bottom: 14px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.card-marker {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  font-size: 0.7rem;
  font-weight: 700;
  flex-shrink: 0;
}

.marker-danger {
  background: rgba(196, 78, 78, 0.15);
  color: var(--level-5);
}

.marker-success {
  background: var(--accent-subtle);
  color: var(--accent);
}

.comparison-card ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.comparison-card li {
  font-size: 0.85rem;
  color: var(--text-secondary);
  display: flex;
  align-items: flex-start;
  gap: 10px;
  line-height: 1.55;
}

.li-marker {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 20px;
  height: 20px;
  font-size: 0.65rem;
  font-weight: 700;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 3px;
  color: var(--text-tertiary);
  flex-shrink: 0;
  margin-top: 2px;
}

/* --- Figure Captions --- */
.figure-caption {
  text-align: center;
  margin-bottom: 20px;
  font-size: 0.82rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.figure-caption-above {
  margin-bottom: 16px;
}

.figure-number {
  font-weight: 700;
  color: var(--text-primary);
  margin-right: 6px;
}

.figure-number::after {
  content: '.';
}

/* --- Response Levels Table --- */
.levels-table-wrap {
  overflow-x: auto;
  border-radius: 10px;
  border: 1px solid var(--border);
}

.levels-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.85rem;
  min-width: 680px;
}

.levels-table thead {
  background: var(--bg-secondary);
}

.levels-table th {
  padding: 12px 18px;
  text-align: left;
  font-weight: 600;
  color: var(--text-secondary);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  border-bottom: 1px solid var(--border);
}

.levels-table td {
  padding: 12px 18px;
  border-bottom: 1px solid var(--border);
  color: var(--text-primary);
  vertical-align: top;
}

.levels-table tbody tr:last-child td { border-bottom: none; }
.levels-table tbody tr { transition: background var(--transition-fast); }
.levels-table tbody tr:hover { background: var(--bg-card); }

.level-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-weight: 700;
  font-size: 0.78rem;
  padding: 2px 8px;
  border-radius: 3px;
  white-space: nowrap;
}

.level-badge .dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
}

.level-0 { color: var(--level-0); } .level-0 .dot { background: var(--level-0); }
.level-1 { color: var(--level-1); } .level-1 .dot { background: var(--level-1); }
.level-2 { color: var(--level-2); } .level-2 .dot { background: var(--level-2); }
.level-3 { color: var(--level-3); } .level-3 .dot { background: var(--level-3); }
.level-4 { color: var(--level-4); } .level-4 .dot { background: var(--level-4); }
.level-5 { color: var(--level-5); } .level-5 .dot { background: var(--level-5); }

/* --- Thesis Quote --- */
.thesis-quote {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  border-radius: 10px;
  padding: 36px 40px;
}

.thesis-quote p {
  font-family: var(--font-serif);
  font-size: 1.05rem;
  font-style: italic;
  line-height: 1.8;
  color: var(--text-primary);
  margin-bottom: 16px;
}

.thesis-quote cite {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-style: normal;
  color: var(--text-tertiary);
}

/* --- Docs Grid --- */
.docs-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 12px;
}

.doc-card {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding: 22px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
  transition: all var(--transition-base);
  text-decoration: none;
  color: var(--text-primary);
}

.doc-card:hover {
  border-color: var(--accent-border);
  color: var(--text-primary);
}

.doc-card-number {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--accent);
  background: var(--accent-subtle);
  padding: 4px 8px;
  border-radius: 4px;
  flex-shrink: 0;
  margin-top: 2px;
}

.doc-card-highlight {
  border-color: var(--accent-border);
  background: var(--accent-subtle);
}

.doc-card h3 {
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 3px;
}

.doc-card p {
  font-size: 0.8rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

.doc-card .arrow {
  color: var(--accent);
  opacity: 0;
  transform: translateX(-4px);
  transition: all var(--transition-fast);
  margin-left: auto;
  flex-shrink: 0;
  align-self: center;
}

.doc-card:hover .arrow {
  opacity: 1;
  transform: translateX(0);
}

/* --- Citation --- */
.citation-block {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 28px 32px;
}

.citation-text {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 20px;
}

.citation-text em {
  color: var(--text-primary);
}

.code-block {
  background: var(--bg-code);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 16px 20px;
  overflow-x: auto;
}

.code-block pre {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  line-height: 1.7;
  color: var(--text-primary);
  margin: 0;
  white-space: pre;
}

.code-block .comment { color: var(--text-tertiary); }

/* --- Footer --- */
.footer {
  border-top: 1px solid var(--border);
  padding: 40px 0;
  background: var(--bg-primary);
}

.footer-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 20px;
  margin-bottom: 24px;
}

.footer-left p {
  color: var(--text-tertiary);
  font-size: 0.78rem;
  margin-top: 4px;
}

.footer-links {
  display: flex;
  gap: 24px;
  list-style: none;
}

.footer-links a {
  color: var(--text-tertiary);
  font-size: 0.78rem;
  transition: color var(--transition-fast);
}
.footer-links a:hover { color: var(--text-primary); }

.footer-bottom {
  border-top: 1px solid var(--border);
  padding-top: 20px;
  text-align: center;
}

.footer-bottom p {
  font-size: 0.75rem;
  color: var(--text-tertiary);
}

/* ============================================================
   TIMELINE
   ============================================================ */
.timeline {
  margin-top: 0;
}

.timeline-track {
  position: relative;
  padding-left: 56px;
  margin-left: 20px;
}

.timeline-track::before {
  content: '';
  position: absolute;
  left: 19px;
  top: 0;
  bottom: 0;
  width: 1px;
  background: var(--border);
}

.tl-event {
  position: relative;
  padding-bottom: 28px;
}
.tl-event:last-child { padding-bottom: 0; }

.tl-marker {
  position: absolute;
  left: -45px;
  top: 6px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  border: 2px solid var(--border);
  background: var(--bg-root);
  z-index: 2;
}

.tl-marker.hosa { background: var(--accent); border-color: var(--accent); }
.tl-marker.dead { background: var(--level-5); border-color: var(--level-5); }
.tl-marker.prom { background: var(--level-3); border-color: var(--level-3); }
.tl-marker.neutral { background: var(--text-tertiary); border-color: var(--text-tertiary); }

.tl-time {
  position: absolute;
  left: -84px;
  top: 2px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--text-secondary);
  text-align: right;
  width: 34px;
}

.tl-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-left: 3px solid var(--border);
  border-radius: 8px;
  padding: 18px 22px;
}

.tl-card.tl-hosa { border-left-color: var(--accent); }
.tl-card.tl-dead { border-left-color: var(--level-5); background: rgba(196, 78, 78, 0.03); }
.tl-card.tl-prom { border-left-color: var(--level-3); background: rgba(212, 138, 78, 0.03); }
.tl-card.tl-neutral { border-left-color: var(--text-tertiary); }

.tl-card-head {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 6px;
  flex-wrap: wrap;
}

.tl-card-head h4 {
  font-size: 0.92rem;
  font-weight: 700;
}

.tl-card p {
  font-size: 0.84rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 6px;
}
.tl-card p:last-child { margin-bottom: 0; }

.tl-metrics {
  display: flex;
  flex-wrap: wrap;
  gap: 5px;
  margin: 8px 0;
}

.tl-pill {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 500;
  padding: 2px 8px;
  border-radius: 3px;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  white-space: nowrap;
}

.tl-pill.accent-pill {
  background: var(--accent-subtle);
  border-color: var(--accent-border);
  color: var(--accent);
}

.tl-badge {
  font-size: 0.62rem;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: 3px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.hosa-badge { background: var(--accent-subtle); color: var(--accent); }
.dead-badge { background: rgba(196, 78, 78, 0.1); color: var(--level-5); }
.prom-badge { background: rgba(212, 138, 78, 0.1); color: var(--level-3); }

.tl-aside {
  font-size: 0.76rem !important;
  color: var(--text-tertiary) !important;
  font-style: italic;
  border-top: 1px solid var(--border);
  padding-top: 6px;
  margin-top: 6px !important;
}

.tl-callout {
  margin: 24px 0 24px 20px;
  padding: 18px 24px;
  background: var(--accent-subtle);
  border: 1px solid var(--accent-border);
  border-radius: 8px;
}

.tl-callout-body strong {
  display: block;
  font-size: 0.88rem;
  color: var(--accent);
  margin-bottom: 4px;
}

.tl-callout-body p {
  font-size: 0.82rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin: 0;
}

.tl-divider {
  display: flex;
  align-items: center;
  gap: 14px;
  margin: 24px 0 24px 20px;
}

.tl-divider::before,
.tl-divider::after {
  content: '';
  flex: 1;
  height: 1px;
  background: rgba(196, 78, 78, 0.15);
}

.tl-divider span {
  font-size: 0.72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--level-4);
  white-space: nowrap;
}

/* ============================================================
   ARCHITECTURE FLOW
   ============================================================ */
.arch-flow {
  margin-top: 0;
  max-width: 760px;
  margin-left: auto;
  margin-right: auto;
}

.arch-layer {
  border: 1px solid var(--border);
  border-radius: 10px;
  overflow: hidden;
}

.arch-layer-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 22px;
  border-bottom: 1px solid var(--border);
}

.arch-kernel { background: var(--bg-card); }
.arch-kernel .arch-layer-head { background: rgba(78, 201, 160, 0.04); }
.arch-user { background: var(--bg-card); }
.arch-user .arch-layer-head { background: rgba(91, 168, 212, 0.04); }

.arch-tag {
  font-size: 0.68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  padding: 3px 10px;
  border-radius: 3px;
}

.kernel-tag { background: var(--accent-subtle); color: var(--accent); }
.user-tag { background: rgba(91, 168, 212, 0.1); color: #5ba8d4; }

.arch-tech {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 500;
  color: var(--text-tertiary);
}

.arch-nodes {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--border);
}
.arch-nodes-stack { grid-template-columns: 1fr; }

.arch-node {
  padding: 22px;
  background: var(--bg-card);
}

.arch-node-icon-wrap {
  color: var(--text-secondary);
  margin-bottom: 8px;
}

.arch-icon {
  width: 20px;
  height: 20px;
}

.arch-node h4 {
  font-size: 0.88rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.arch-node ul, .arch-node ol { padding-left: 0; list-style: none; }
.arch-node ul li, .arch-node ol li {
  font-size: 0.8rem;
  color: var(--text-secondary);
  padding: 2px 0;
  line-height: 1.5;
}

.arch-node-head {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 12px;
}
.arch-node-head .arch-node-icon-wrap { margin-bottom: 0; }

.cortex-steps {
  counter-reset: step;
  padding-left: 0 !important;
}

.cortex-steps li {
  counter-increment: step;
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 5px 0 !important;
  border-bottom: 1px solid var(--border);
}
.cortex-steps li:last-child { border-bottom: none; }

.cortex-steps li::before {
  content: counter(step);
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 20px;
  height: 20px;
  font-size: 0.68rem;
  font-weight: 700;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 3px;
  color: var(--text-secondary);
  flex-shrink: 0;
  margin-top: 1px;
}

.arch-comms-items {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 6px;
}

.arch-comms-chip {
  font-size: 0.73rem;
  font-weight: 500;
  padding: 3px 10px;
  border-radius: 3px;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  color: var(--text-secondary);
}

.arch-comms-note {
  font-size: 0.76rem;
  color: var(--text-tertiary);
  font-style: italic;
  margin: 0;
}

.arch-bridge {
  display: flex;
  justify-content: center;
  gap: 40px;
  padding: 14px 0;
}

.arch-bridge-item {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-secondary);
}

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 860px) {
  .nav-links {
    display: none;
    position: fixed;
    top: var(--nav-height);
    left: 0; right: 0; bottom: 0;
    background: var(--bg-root);
    flex-direction: column;
    align-items: stretch;
    padding: 24px;
    gap: 4px;
    border-top: 1px solid var(--border);
    overflow-y: auto;
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 12px 16px; font-size: 1rem; }
  .nav-toggle { display: block; }

  .hero { padding: 120px 0 64px; }
  .section { padding: 64px 0; }
  .comparison-grid { grid-template-columns: 1fr; }
  .section-header { margin-bottom: 40px; }

  .hero-meta { gap: 20px; }

  .arch-nodes { grid-template-columns: 1fr; }
  .arch-bridge { gap: 20px; flex-wrap: wrap; }

  .timeline-track { padding-left: 44px; margin-left: 12px; }
  .tl-time { left: -66px; font-size: 0.66rem; width: 28px; }
  .tl-marker { left: -37px; width: 8px; height: 8px; }
  .tl-card { padding: 14px 16px; }

  .abstract-block { padding: 24px; }
  .thesis-quote { padding: 24px 28px; }
  .citation-block { padding: 20px 24px; }
}

@media (max-width: 480px) {
  .hero h1 { font-size: 1.75rem; }
  .hero-ctas { flex-direction: column; align-items: stretch; }
  .btn { justify-content: center; }
  .feature-card { padding: 22px 18px; }
  .footer-content { flex-direction: column; align-items: flex-start; }
  .hero-meta { flex-direction: column; gap: 12px; }

  .timeline-track { padding-left: 36px; margin-left: 8px; }
  .tl-time { left: -54px; font-size: 0.62rem; width: 24px; }
  .tl-marker { left: -29px; }
  .tl-callout { margin-left: 8px; padding: 14px; }
  .tl-divider { margin-left: 8px; }
}