:root {
    --bg: #FAFAFA;
    --surface: #FFFFFF;
    --ink: #0A0A0A;
    --ink-2: #1F1F1F;
    --muted: #6B7280;
    --line: #E5E7EB;
    --line-2: #F0F0F0;
    --accent: #2563EB;
    --accent-2: #1D4ED8;
    --amber: #B45309;
    --tag: #F3F4F6;
    --max: 1180px;
  }

  @media (prefers-color-scheme: dark) {
    :root {
      --bg: #0B0C0E;
      --surface: #111317;
      --ink: #F4F4F5;
      --ink-2: #D4D4D8;
      --muted: #9CA3AF;
      --line: #1F2937;
      --line-2: #16181D;
      --accent: #60A5FA;
      --accent-2: #93C5FD;
      --amber: #FBBF24;
      --tag: #1A1D22;
    }
  }

  * { box-sizing: border-box; }
  html { scroll-behavior: smooth; }
  body {
    margin: 0;
    background: var(--bg);
    color: var(--ink);
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    font-size: 16px;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    text-rendering: optimizeLegibility;
  }

  .wrap { max-width: var(--max); margin: 0 auto; padding: 0 24px; }

  /* ---------- NAV ---------- */
  nav {
    position: sticky; top: 0; z-index: 50;
    background: rgba(250, 250, 250, 0.85);
    backdrop-filter: saturate(180%) blur(12px);
    -webkit-backdrop-filter: saturate(180%) blur(12px);
    border-bottom: 1px solid var(--line);
  }
  @media (prefers-color-scheme: dark) {
    nav { background: rgba(11, 12, 14, 0.85); }
  }
  nav .wrap {
    display: flex; align-items: center; justify-content: space-between;
    height: 60px;
  }
  nav .brand {
    font-family: 'JetBrains Mono', monospace;
    font-size: 13px; font-weight: 500; letter-spacing: 0.02em;
    color: var(--ink);
  }
  nav .brand span { color: var(--accent); }
  nav ul {
    list-style: none; display: flex; gap: 28px; margin: 0; padding: 0;
  }
  nav ul a {
    color: var(--ink-2); text-decoration: none; font-size: 14px; font-weight: 500;
    transition: color 0.2s;
  }
  nav ul a:hover { color: var(--accent); }
  nav .num {
    font-family: 'JetBrains Mono', monospace;
    font-size: 11px; color: var(--muted); margin-right: 6px;
  }
  @media (max-width: 720px) {
    nav ul { display: none; }
  }

  /* ---------- HERO ---------- */
  .hero {
    padding: 96px 0 80px;
    border-bottom: 1px solid var(--line);
  }
  .eyebrow {
    font-family: 'JetBrains Mono', monospace;
    font-size: 12px; letter-spacing: 0.08em; text-transform: uppercase;
    color: var(--accent); margin-bottom: 24px;
  }
  .hero h1 {
    font-family: 'Inter', sans-serif;
    font-weight: 600; font-size: clamp(48px, 8vw, 92px);
    line-height: 0.98; letter-spacing: -0.035em;
    margin: 0 0 32px;
  }
  .hero h1 em {
    font-family: 'Source Serif 4', serif;
    font-style: italic; font-weight: 400;
    color: var(--accent);
  }
  .hero .lede {
    font-size: 20px; line-height: 1.5; color: var(--ink-2);
    max-width: 720px; margin: 0 0 36px;
  }
  .hero .lede strong { font-weight: 600; color: var(--ink); }

  .chips {
    display: flex; flex-wrap: wrap; gap: 10px; margin-bottom: 36px;
  }
  .chip {
    display: inline-flex; align-items: center; gap: 8px;
    padding: 6px 12px; border: 1px solid var(--line);
    border-radius: 999px; font-size: 13px; color: var(--ink-2);
    background: var(--surface);
  }
  .chip .dot {
    width: 7px; height: 7px; border-radius: 50%;
    background: var(--accent);
  }
  .chip .dot.amber { background: var(--amber); }
  .chip .dot.green { background: #10B981; }

  .cta-row {
    display: flex; flex-wrap: wrap; gap: 12px;
  }
  .btn {
    display: inline-flex; align-items: center; gap: 8px;
    padding: 12px 20px; border-radius: 8px;
    font-size: 14px; font-weight: 500;
    text-decoration: none; transition: all 0.2s;
    border: 1px solid transparent;
  }
  .btn.primary { background: var(--ink); color: var(--bg); }
  .btn.primary:hover { background: var(--accent); }
  .btn.secondary {
    background: transparent; color: var(--ink);
    border-color: var(--line);
  }
  .btn.secondary:hover { border-color: var(--ink); }
  .btn .arrow { transition: transform 0.2s; }
  .btn:hover .arrow { transform: translateX(3px); }

  /* ---------- SECTION ---------- */
  section { padding: 96px 0; border-bottom: 1px solid var(--line); }
  .section-head {
    display: grid; grid-template-columns: 200px 1fr; gap: 48px;
    margin-bottom: 56px; align-items: baseline;
  }
  .section-head .label {
    font-family: 'JetBrains Mono', monospace;
    font-size: 12px; letter-spacing: 0.08em; text-transform: uppercase;
    color: var(--muted);
  }
  .section-head h2 {
    font-size: clamp(28px, 4vw, 40px);
    font-weight: 600; letter-spacing: -0.02em;
    margin: 0; line-height: 1.15;
  }
  .section-head h2 em {
    font-family: 'Source Serif 4', serif;
    font-style: italic; font-weight: 400; color: var(--accent);
  }
  @media (max-width: 720px) {
    .section-head { grid-template-columns: 1fr; gap: 12px; margin-bottom: 36px; }
    section { padding: 64px 0; }
  }

  /* ---------- ABOUT ---------- */
  .about-grid {
    display: grid; grid-template-columns: 200px 1fr; gap: 48px;
  }
  .about-meta {
    font-family: 'JetBrains Mono', monospace; font-size: 12px;
    color: var(--muted); line-height: 1.9;
  }
  .about-meta dt {
    color: var(--muted); margin-top: 14px;
    font-weight: 400; letter-spacing: 0.04em;
  }
  .about-meta dt:first-child { margin-top: 0; }
  .about-meta dd {
    color: var(--ink); margin: 2px 0 0; font-weight: 500;
  }
  .about-body p {
    font-size: 18px; line-height: 1.75; color: var(--ink-2);
    margin: 0 0 18px; max-width: 680px;
  }
  .about-body p:last-child { margin-bottom: 0; }
  .about-body strong { color: var(--ink); font-weight: 600; }
  .about-body .pull {
    font-family: 'Source Serif 4', serif;
    font-style: italic;
    font-size: 22px; line-height: 1.5;
    color: var(--ink); margin: 28px 0;
    padding-left: 20px;
    border-left: 2px solid var(--accent);
  }
  @media (max-width: 720px) {
    .about-grid { grid-template-columns: 1fr; gap: 24px; }
  }

  /* ---------- PROJECTS ---------- */
  .projects {
    display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px;
  }
  @media (max-width: 860px) { .projects { grid-template-columns: 1fr; } }

  .proj {
    background: var(--surface); border: 1px solid var(--line);
    border-radius: 14px; overflow: hidden;
    display: flex; flex-direction: column;
    transition: border-color 0.2s, transform 0.2s;
  }
  .proj:hover { border-color: var(--ink); transform: translateY(-2px); }

  .proj .thumb {
    aspect-ratio: 16 / 10; background: var(--line-2);
    display: flex; align-items: center; justify-content: center;
    overflow: hidden; position: relative;
    border-bottom: 1px solid var(--line);
  }
  .proj .thumb img {
    width: 100%; height: 100%; object-fit: cover;
    transition: transform 0.4s;
  }
  .proj:hover .thumb img { transform: scale(1.03); }

  /* placeholder thumbnails for confidential projects */
  .thumb-svg {
    width: 100%; height: 100%; padding: 32px;
    display: flex; align-items: center; justify-content: center;
  }
  .thumb-svg svg { width: 100%; height: 100%; max-width: 320px; }

  .proj .body { padding: 24px 24px 28px; flex: 1; display: flex; flex-direction: column; }
  .proj .meta {
    font-family: 'JetBrains Mono', monospace; font-size: 11px;
    color: var(--muted); letter-spacing: 0.06em; text-transform: uppercase;
    margin-bottom: 12px;
    display: flex; gap: 14px; align-items: center;
  }
  .proj .meta .num { color: var(--accent); font-weight: 500; }
  .proj h3 {
    font-size: 22px; font-weight: 600; letter-spacing: -0.01em;
    margin: 0 0 10px; line-height: 1.25;
  }
  .proj p {
    font-size: 15px; color: var(--ink-2); line-height: 1.6;
    margin: 0 0 18px;
  }

  .impact {
    display: flex; gap: 20px; margin: 0 0 18px;
    padding: 12px 0; border-top: 1px solid var(--line-2);
    border-bottom: 1px solid var(--line-2);
  }
  .impact div { flex: 1; }
  .impact .num {
    font-family: 'Source Serif 4', serif;
    font-size: 22px; font-weight: 600; color: var(--accent);
    display: block; line-height: 1;
  }
  .impact .lab {
    font-size: 11px; color: var(--muted);
    text-transform: uppercase; letter-spacing: 0.06em;
    margin-top: 4px;
  }

  .tags {
    display: flex; flex-wrap: wrap; gap: 6px; margin-top: auto;
  }
  .tag {
    font-family: 'JetBrains Mono', monospace; font-size: 11px;
    padding: 4px 8px; background: var(--tag);
    color: var(--ink-2); border-radius: 4px;
    letter-spacing: 0.02em;
  }

  /* ---------- SKILLS ---------- */
  .skills-grid {
    display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px;
  }
  @media (max-width: 900px) { .skills-grid { grid-template-columns: repeat(2, 1fr); } }
  @media (max-width: 540px) { .skills-grid { grid-template-columns: 1fr; } }

  .skill-cat {
    padding: 20px; background: var(--surface);
    border: 1px solid var(--line); border-radius: 12px;
  }
  .skill-cat h4 {
    font-family: 'JetBrains Mono', monospace;
    font-size: 11px; color: var(--accent);
    letter-spacing: 0.08em; text-transform: uppercase;
    margin: 0 0 14px; font-weight: 500;
  }
  .skill-cat ul {
    list-style: none; margin: 0; padding: 0;
    display: flex; flex-direction: column; gap: 6px;
  }
  .skill-cat li {
    font-size: 14px; color: var(--ink); font-weight: 500;
    display: flex; justify-content: space-between; align-items: center;
  }
  .skill-cat li .lvl {
    font-family: 'JetBrains Mono', monospace;
    font-size: 10px; color: var(--muted);
  }

  /* ---------- EXPERIENCE / TIMELINE ---------- */
  .timeline { position: relative; padding-left: 24px; }
  .timeline::before {
    content: ''; position: absolute; left: 6px; top: 8px; bottom: 8px;
    width: 1px; background: var(--line);
  }
  .tl-item { position: relative; padding-bottom: 36px; }
  .tl-item:last-child { padding-bottom: 0; }
  .tl-item::before {
    content: ''; position: absolute; left: -24px; top: 6px;
    width: 13px; height: 13px; border-radius: 50%;
    background: var(--bg); border: 2px solid var(--accent);
  }
  .tl-item.muted::before { border-color: var(--muted); }
  .tl-row {
    display: grid; grid-template-columns: 200px 1fr; gap: 32px;
    align-items: baseline;
  }
  @media (max-width: 720px) {
    .tl-row { grid-template-columns: 1fr; gap: 4px; }
  }
  .tl-date {
    font-family: 'JetBrains Mono', monospace; font-size: 12px;
    color: var(--muted); letter-spacing: 0.04em;
  }
  .tl-content h4 {
    font-size: 18px; font-weight: 600; margin: 0 0 4px;
    letter-spacing: -0.005em;
  }
  .tl-content .org {
    font-size: 14px; color: var(--accent); margin-bottom: 10px;
  }
  .tl-content p {
    font-size: 14px; color: var(--ink-2); line-height: 1.65;
    margin: 0 0 8px; max-width: 660px;
  }
  .tl-content ul {
    margin: 6px 0 0; padding-left: 18px;
    font-size: 14px; color: var(--ink-2); line-height: 1.7;
    max-width: 660px;
  }

  /* ---------- PUBLICATIONS ---------- */
  .pubs { display: flex; flex-direction: column; gap: 20px; }
  .pub {
    padding: 20px 0; border-top: 1px solid var(--line);
    display: grid; grid-template-columns: 200px 1fr 120px; gap: 32px;
    align-items: start;
  }
  .pub:first-child { border-top: none; padding-top: 0; }
  .pub .ptype {
    font-family: 'JetBrains Mono', monospace; font-size: 11px;
    letter-spacing: 0.08em; text-transform: uppercase;
    color: var(--muted);
  }
  .pub .ptype .badge {
    display: inline-block; padding: 2px 8px; border-radius: 4px;
    background: var(--tag); color: var(--ink); margin-right: 6px;
  }
  .pub h4 {
    font-family: 'Source Serif 4', serif;
    font-size: 18px; font-weight: 400; line-height: 1.4;
    margin: 0 0 6px; letter-spacing: -0.005em;
  }
  .pub .pmeta {
    font-size: 13px; color: var(--muted);
  }
  .pub a.plink {
    font-family: 'JetBrains Mono', monospace; font-size: 12px;
    color: var(--accent); text-decoration: none;
    text-align: right; white-space: nowrap;
  }
  .pub a.plink:hover { text-decoration: underline; }
  @media (max-width: 860px) {
    .pub { grid-template-columns: 1fr; gap: 8px; }
    .pub a.plink { text-align: left; }
  }

  /* ---------- EDUCATION ---------- */
  .edu-grid {
    display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px;
  }
  @media (max-width: 720px) { .edu-grid { grid-template-columns: 1fr; } }
  .edu-card {
    padding: 28px; background: var(--surface);
    border: 1px solid var(--line); border-radius: 14px;
  }
  .edu-card .deg {
    font-size: 13px; font-family: 'JetBrains Mono', monospace;
    color: var(--accent); letter-spacing: 0.04em;
    text-transform: uppercase; margin-bottom: 8px;
  }
  .edu-card h4 {
    font-size: 22px; font-weight: 600; margin: 0 0 4px;
    letter-spacing: -0.01em;
  }
  .edu-card .school {
    font-size: 14px; color: var(--ink-2); margin-bottom: 16px;
  }
  .edu-card .stats {
    display: flex; gap: 24px; padding: 14px 0;
    border-top: 1px solid var(--line-2);
    border-bottom: 1px solid var(--line-2); margin-bottom: 14px;
  }
  .edu-card .stats div .v {
    font-family: 'Source Serif 4', serif;
    font-size: 18px; font-weight: 600; color: var(--ink);
    display: block;
  }
  .edu-card .stats div .l {
    font-size: 11px; color: var(--muted);
    letter-spacing: 0.06em; text-transform: uppercase; margin-top: 2px;
  }
  .edu-card p {
    font-size: 14px; color: var(--ink-2); line-height: 1.65;
    margin: 0;
  }

  /* ---------- CONTACT ---------- */
  .contact-grid {
    display: grid; grid-template-columns: 1fr 1fr; gap: 48px;
    align-items: start;
  }
  @media (max-width: 720px) { .contact-grid { grid-template-columns: 1fr; gap: 32px; } }
  .contact-pitch {
    font-family: 'Source Serif 4', serif;
    font-size: clamp(28px, 4vw, 38px);
    line-height: 1.25; letter-spacing: -0.015em;
    margin: 0 0 24px; font-weight: 400;
  }
  .contact-pitch em { font-style: italic; color: var(--accent); }
  .contact-list {
    display: flex; flex-direction: column; gap: 8px; margin: 0; padding: 0;
    list-style: none;
  }
  .contact-list li a {
    display: flex; justify-content: space-between; align-items: center;
    padding: 16px 0; border-bottom: 1px solid var(--line);
    color: var(--ink); text-decoration: none;
    transition: padding 0.2s;
  }
  .contact-list li a:hover { padding-left: 8px; color: var(--accent); }
  .contact-list .lab {
    font-family: 'JetBrains Mono', monospace; font-size: 11px;
    color: var(--muted); letter-spacing: 0.06em; text-transform: uppercase;
  }
  .contact-list .val {
    font-size: 15px; font-weight: 500;
  }
  .contact-list .arrow { color: var(--muted); }

  /* ---------- FOOTER ---------- */
  footer {
    padding: 32px 0 48px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 11px; color: var(--muted);
    display: flex; justify-content: space-between; flex-wrap: wrap; gap: 12px;
    letter-spacing: 0.04em;
  }

  /* ---------- UTILITY ---------- */
  .id-anchor { scroll-margin-top: 80px; }
  ::selection { background: var(--accent); color: var(--bg); }

/* ============== CASE STUDY PAGES ============== */
.case-nav {
  position: sticky; top: 0; z-index: 50;
  background: rgba(250, 250, 250, 0.85);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--line);
}
@media (prefers-color-scheme: dark) {
  .case-nav { background: rgba(11, 12, 14, 0.85); }
}
.case-nav .wrap {
  display: flex; align-items: center; justify-content: space-between;
  height: 60px;
}
.back-link {
  font-family: 'JetBrains Mono', monospace;
  font-size: 13px; font-weight: 500; color: var(--ink);
  text-decoration: none; transition: color 0.2s;
}
.back-link:hover { color: var(--accent); }
.case-counter {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px; color: var(--muted);
  letter-spacing: 0.06em;
}

.case-hero {
  padding: 80px 0 64px;
  border-bottom: 1px solid var(--line);
}
.case-hero h1 {
  font-family: 'Inter', sans-serif;
  font-weight: 600;
  font-size: clamp(32px, 5vw, 56px);
  line-height: 1.08; letter-spacing: -0.025em;
  margin: 0 0 24px;
  max-width: 880px;
}
.case-hero h1 em {
  font-family: 'Source Serif 4', serif;
  font-style: italic; font-weight: 400;
  color: var(--accent);
}
.case-hero .lede {
  font-size: 19px; line-height: 1.55;
  color: var(--ink-2);
  max-width: 720px;
  margin: 0 0 40px;
}

.case-meta {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  border-top: 1px solid var(--line);
  padding-top: 24px;
  max-width: 880px;
}
.case-meta > div {
  display: flex; flex-direction: column; gap: 4px;
}
.case-meta .lab {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px; color: var(--muted);
  letter-spacing: 0.06em; text-transform: uppercase;
}
.case-meta .val {
  font-size: 14px; color: var(--ink); font-weight: 500;
}
.case-meta .val a {
  color: var(--accent); text-decoration: none;
}
.case-meta .val a:hover { text-decoration: underline; }
@media (max-width: 720px) {
  .case-meta { grid-template-columns: repeat(2, 1fr); gap: 16px; }
}

.case-section { padding: 80px 0; border-bottom: 1px solid var(--line); }
@media (max-width: 720px) { .case-section { padding: 56px 0; } }

.prose {
  max-width: 720px;
  margin-left: 200px;
}
@media (max-width: 720px) {
  .prose { margin-left: 0; }
}
.prose p {
  font-size: 17px;
  line-height: 1.75;
  color: var(--ink-2);
  margin: 0 0 18px;
}
.prose p strong { color: var(--ink); font-weight: 600; }
.prose a { color: var(--accent); text-decoration: none; }
.prose a:hover { text-decoration: underline; }
.prose h3 {
  font-family: 'Inter', sans-serif;
  font-size: 20px; font-weight: 600;
  letter-spacing: -0.01em;
  margin: 36px 0 14px;
  color: var(--ink);
}
.prose ul {
  margin: 0 0 18px; padding-left: 22px;
  font-size: 17px; line-height: 1.75; color: var(--ink-2);
}
.prose ul li { margin-bottom: 6px; }
.prose ul li strong { color: var(--ink); }

.formula {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 20px 24px;
  margin: 24px 0;
  font-family: 'Source Serif 4', serif;
  font-style: italic;
  font-size: 18px;
  text-align: center;
  color: var(--ink);
  overflow-x: auto;
}

.callout {
  background: var(--surface);
  border: 1px solid var(--line);
  border-left: 3px solid var(--accent);
  border-radius: 0 8px 8px 0;
  padding: 18px 22px;
  margin: 24px 0;
}
.callout p { margin: 0; font-size: 16px; }
.callout .label {
  font-family: 'JetBrains Mono', monospace;
  font-size: 10px; letter-spacing: 0.08em; text-transform: uppercase;
  color: var(--accent); margin-bottom: 6px; display: block;
}

.figure {
  margin: 32px 0;
  border-radius: 10px; overflow: hidden;
  border: 1px solid var(--line);
  background: var(--surface);
}
.figure img {
  width: 100%; height: auto; display: block;
  background: #FFFFFF;
}
.figure figcaption {
  padding: 12px 18px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px; color: var(--muted);
  letter-spacing: 0.04em;
  border-top: 1px solid var(--line);
  background: var(--surface);
}
.figure figcaption strong { color: var(--ink); margin-right: 8px; }

.figure-row {
  display: grid; grid-template-columns: 1fr 1fr; gap: 20px;
  margin: 32px 0;
}
.figure-row .figure { margin: 0; }
@media (max-width: 720px) {
  .figure-row { grid-template-columns: 1fr; gap: 16px; }
}

.metrics-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  margin: 24px 0 32px;
}
.metrics-grid .metric {
  padding: 18px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 10px;
}
.metrics-grid .metric .v {
  font-family: 'Source Serif 4', serif;
  font-size: 24px; font-weight: 600;
  color: var(--accent);
  display: block; line-height: 1.1;
}
.metrics-grid .metric .l {
  font-size: 12px; color: var(--muted);
  margin-top: 6px;
  letter-spacing: 0.04em;
}
@media (max-width: 720px) {
  .metrics-grid { grid-template-columns: repeat(2, 1fr); }
}

.tools-list {
  display: flex; flex-wrap: wrap; gap: 8px;
  max-width: 720px;
  margin-left: 200px;
  margin-top: 20px;
}
@media (max-width: 720px) { .tools-list { margin-left: 0; } }
.tools-list .tag {
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px; padding: 6px 10px;
  background: var(--tag);
  color: var(--ink-2);
  border-radius: 6px;
}

.case-footer {
  padding: 40px 0;
  border-top: 1px solid var(--line);
}
.case-footer .nav-row {
  display: flex; justify-content: space-between; align-items: center;
  flex-wrap: wrap; gap: 16px;
}
.case-footer .nav-row a {
  font-family: 'JetBrains Mono', monospace;
  font-size: 13px; color: var(--ink);
  text-decoration: none;
}
.case-footer .nav-row a:hover { color: var(--accent); }
.case-footer .next-link {
  padding: 12px 20px;
  background: var(--ink); color: var(--bg);
  border-radius: 8px;
  transition: background 0.2s;
}
.case-footer .next-link:hover { background: var(--accent); color: var(--bg) !important; }

/* ============== CARD AS LINK ============== */
.proj-link {
  text-decoration: none;
  color: inherit;
  cursor: pointer;
}
.proj-link:hover { color: inherit; }

.proj-cta {
  display: inline-flex; align-items: center; gap: 6px;
  margin-top: 14px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px; font-weight: 500;
  color: var(--accent);
  letter-spacing: 0.04em;
  transition: gap 0.2s;
}
.proj-link:hover .proj-cta { gap: 10px; }

/* ============== HAMBURGER (MOBILE NAV) ============== */
.nav-toggle {
  display: none;
  background: transparent;
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 9px 11px;
  cursor: pointer;
  color: var(--ink);
  line-height: 0;
  transition: border-color 0.2s;
  -webkit-tap-highlight-color: transparent;
}
.nav-toggle:hover { border-color: var(--ink); }
.nav-toggle .bar {
  display: block;
  width: 18px;
  height: 1.5px;
  background: currentColor;
  margin: 4px 0;
  transition: transform 0.22s ease, opacity 0.18s ease;
}
.nav-toggle[aria-expanded="true"] .bar:nth-child(1) {
  transform: translateY(5.5px) rotate(45deg);
}
.nav-toggle[aria-expanded="true"] .bar:nth-child(2) {
  opacity: 0;
}
.nav-toggle[aria-expanded="true"] .bar:nth-child(3) {
  transform: translateY(-5.5px) rotate(-45deg);
}

@media (max-width: 720px) {
  .nav-toggle { display: inline-flex; flex-direction: column; }

  #site-nav ul {
    display: flex;
    flex-direction: column;
    gap: 0;
    position: fixed;
    top: 60px;
    left: 0;
    right: 0;
    margin: 0;
    padding: 8px 24px 32px;
    background: var(--bg);
    border-bottom: 1px solid var(--line);
    box-shadow: 0 12px 28px rgba(0, 0, 0, 0.08);
    transform: translateY(-110%);
    transition: transform 0.28s cubic-bezier(0.16, 1, 0.3, 1);
    max-height: calc(100vh - 60px);
    overflow-y: auto;
  }
  #site-nav.open ul {
    transform: translateY(0);
  }
  #site-nav ul li {
    border-bottom: 1px solid var(--line-2);
  }
  #site-nav ul li:last-child { border-bottom: none; }
  #site-nav ul a {
    display: flex;
    align-items: baseline;
    padding: 18px 0;
    font-size: 17px;
  }
  #site-nav ul a .num {
    font-size: 11px;
    margin-right: 14px;
    color: var(--accent);
  }
}

/* ============== CO-WORK PAGE ============== */
/* Two-track layout (Research / Project) */
.tracks {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  margin-left: 200px;
  max-width: 720px;
}
@media (max-width: 720px) {
  .tracks { grid-template-columns: 1fr; gap: 16px; margin-left: 0; }
}
.track {
  background: var(--surface);
  border: 1px solid var(--line);
  border-top: 3px solid var(--accent);
  border-radius: 12px;
  padding: 22px;
}
.track .track-label {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 14px;
  font-weight: 500;
}
.track ul {
  margin: 0; padding-left: 18px;
  font-size: 14px; line-height: 1.6; color: var(--ink-2);
}
.track ul li { margin-bottom: 8px; }
.track ul li strong { color: var(--ink); font-weight: 600; }

/* Past collaboration cards grid */
.collab-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}
@media (max-width: 860px) {
  .collab-grid { grid-template-columns: 1fr; }
}
.collab-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 22px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  transition: border-color 0.2s, transform 0.2s;
}
.collab-card:hover { border-color: var(--ink); transform: translateY(-2px); }
.collab-card .meta {
  display: flex; justify-content: space-between; align-items: baseline;
  font-family: 'JetBrains Mono', monospace; font-size: 11px;
  color: var(--muted); letter-spacing: 0.06em; text-transform: uppercase;
  margin-bottom: 4px;
}
.collab-card .meta .num { color: var(--accent); font-weight: 600; }
.collab-card h3 {
  font-size: 18px; font-weight: 600; line-height: 1.25;
  margin: 0; letter-spacing: -0.01em;
}
.collab-card .collab-with {
  font-size: 13px; color: var(--ink-2);
  font-style: italic;
  font-family: 'Source Serif 4', serif;
}
.collab-card .collab-with strong { color: var(--ink); font-weight: 600; font-style: normal; font-family: inherit; }
.collab-card p {
  font-size: 14px; line-height: 1.6; color: var(--ink-2); margin: 4px 0 0;
  flex: 1;
}
.collab-card .collab-output {
  display: flex; gap: 10px; align-items: baseline;
  padding: 10px 0;
  border-top: 1px solid var(--line-2);
  border-bottom: 1px solid var(--line-2);
  font-size: 13px; color: var(--ink);
}
.collab-card .collab-output .lab {
  font-family: 'JetBrains Mono', monospace; font-size: 10px;
  letter-spacing: 0.06em; text-transform: uppercase;
  color: var(--muted); flex-shrink: 0;
}
.collab-card .collab-links {
  display: flex; flex-wrap: wrap; gap: 14px;
  font-family: 'JetBrains Mono', monospace; font-size: 12px;
}
.collab-card .collab-links a {
  color: var(--accent); text-decoration: none;
  transition: color 0.2s;
}
.collab-card .collab-links a:hover { color: var(--ink); }

/* Engagement process strip */
.process {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
}
@media (max-width: 860px) {
  .process { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 540px) {
  .process { grid-template-columns: 1fr; }
}
.process-step {
  padding: 18px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 10px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.process-step .step-num {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--accent);
  font-weight: 500;
}
.process-step .step-title {
  font-size: 16px; font-weight: 600; color: var(--ink);
  letter-spacing: -0.005em;
}
.process-step p {
  font-size: 13px; line-height: 1.55; color: var(--ink-2); margin: 4px 0 0;
}

/* Proposal guide list */
.guide-list {
  margin: 28px 0 0;
  padding: 0;
  max-width: 720px;
  margin-left: 200px;
}
@media (max-width: 720px) {
  .guide-list { margin-left: 0; }
}
.guide-list dt {
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--accent);
  margin-top: 16px; margin-bottom: 4px;
  font-weight: 500;
}
.guide-list dt:first-child { margin-top: 0; }
.guide-list dd {
  font-size: 15px; line-height: 1.6;
  color: var(--ink-2); margin: 0;
  padding-left: 14px; border-left: 2px solid var(--line);
}

/* Subtle footer co-work link (used on index + case study pages) */
.cowork-link {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  color: var(--muted);
  text-decoration: none;
  letter-spacing: 0.04em;
  transition: color 0.2s;
}
.cowork-link:hover { color: var(--accent); }

.cowork-strip {
  margin-top: 14px;
  padding-top: 14px;
  border-top: 1px solid var(--line-2);
  text-align: right;
}

/* ============== KEYWORD CLOUD (cowork) ============== */
.cloud {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
  padding: 8px 0;
}
.kw-tag {
  font-family: 'JetBrains Mono', monospace;
  padding: 7px 13px;
  background: var(--tag);
  color: var(--ink-2);
  border: 1px solid transparent;
  border-radius: 999px;
  cursor: pointer;
  transition: background 0.18s, color 0.18s, border-color 0.18s, transform 0.12s;
  -webkit-tap-highlight-color: transparent;
  letter-spacing: 0.01em;
}
.kw-tag:hover {
  background: var(--surface);
  border-color: var(--accent);
  color: var(--accent);
  transform: translateY(-1px);
}
.kw-tag.active {
  background: var(--accent);
  color: #FFFFFF;
  border-color: var(--accent);
}
.kw-tag.size-1 { font-size: 12px; padding: 5px 10px; }
.kw-tag.size-2 { font-size: 14px; padding: 7px 13px; }
.kw-tag.size-3 { font-size: 16px; padding: 9px 16px; font-weight: 500; }

.cloud-hint {
  margin-top: 14px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  color: var(--muted);
  letter-spacing: 0.04em;
}

.cloud-detail {
  position: relative;
  margin-top: 22px;
  padding: 22px 26px 24px;
  background: var(--surface);
  border: 1px solid var(--accent);
  border-radius: 12px;
}
.cloud-detail .kw-close {
  position: absolute;
  top: 10px;
  right: 14px;
  background: transparent;
  border: none;
  color: var(--muted);
  font-size: 22px;
  line-height: 1;
  cursor: pointer;
  padding: 4px 8px;
  transition: color 0.18s;
}
.cloud-detail .kw-close:hover { color: var(--ink); }

.cloud-detail .kw-cat {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--accent);
  margin-bottom: 6px;
}
.cloud-detail .kw-label {
  font-size: 24px;
  font-weight: 600;
  letter-spacing: -0.01em;
  color: var(--ink);
  margin-bottom: 8px;
}
.cloud-detail .kw-level {
  font-family: 'Source Serif 4', serif;
  font-style: italic;
  font-size: 15px;
  color: var(--ink-2);
  margin-bottom: 18px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--line-2);
}
.cloud-detail .kw-level span {
  font-family: 'JetBrains Mono', monospace;
  font-style: normal;
  font-size: 10px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--muted);
  margin-right: 8px;
}

.cloud-detail .kw-where-label,
.cloud-detail .kw-links-label {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--accent);
  margin-bottom: 8px;
  font-weight: 500;
}
.cloud-detail .kw-links-label { margin-top: 16px; }

.cloud-detail .kw-where {
  margin: 0 0 4px;
  padding-left: 18px;
  font-size: 14px;
  line-height: 1.6;
  color: var(--ink-2);
}
.cloud-detail .kw-where li { margin-bottom: 4px; }

.cloud-detail .kw-links {
  display: flex;
  flex-wrap: wrap;
  gap: 14px 18px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
}
.cloud-detail .kw-links a {
  color: var(--accent);
  text-decoration: none;
  transition: color 0.18s;
}
.cloud-detail .kw-links a:hover { color: var(--ink); text-decoration: underline; }

/* When 5+ collab cards leave a lone card, span it full width on desktop */
.collab-grid .collab-card:last-child:nth-child(odd) {
  grid-column: 1 / -1;
}
@media (max-width: 860px) {
  .collab-grid .collab-card:last-child:nth-child(odd) { grid-column: auto; }
}

/* ============== COLLAB CLUSTERS ============== */
.collab-cluster {
  margin-bottom: 36px;
}
.collab-cluster:last-child { margin-bottom: 0; }

.cluster-label {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  font-family: 'JetBrains Mono', monospace;
  font-size: 13px;
  color: var(--ink-2);
  letter-spacing: 0.04em;
  margin-bottom: 14px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--line);
}
.cluster-label .cluster-tag {
  display: inline-block;
  padding: 4px 10px;
  background: var(--accent);
  color: #FFFFFF;
  border-radius: 4px;
  font-size: 11px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  font-weight: 500;
}

/* Last odd-card span rule applies per cluster grid */
.collab-cluster .collab-grid .collab-card:last-child:nth-child(odd) {
  grid-column: 1 / -1;
}
@media (max-width: 860px) {
  .collab-cluster .collab-grid .collab-card:last-child:nth-child(odd) { grid-column: auto; }
}