:root {
    --tudelft-blue: #00A6D6;
    --tudelft-dark: #00587A;
    --tudelft-darker: #003B52;
    --tudelft-light: #E6F7FC;
    --tudelft-lighter: #F0FAFC;
    --tudelft-lightest: #F8FCFE;
    --text: #1a1a1a;
    --text-secondary: #444;
    --border: #d0d0d0;
    --bg: #ffffff;
    --year-bg: #f0f8fb;
    --highlight-bg: #f8fcfe;
    --highlight-border: #00A6D6;
  }
  * { margin: 0; padding: 0; box-sizing: border-box; }
  body {
    font-family: 'Segoe UI', 'Helvetica Neue', Arial, sans-serif;
    color: var(--text);
    background: var(--bg);
    line-height: 1.6;
    max-width: 1200px;
    margin: 0 auto;
    padding: 40px 24px 80px;
  }
  @media (max-width: 768px) {
    body {
      padding: 20px 16px 40px;
      max-width: 100%;
    }
  }
  @media (max-width: 480px) {
    body {
      padding: 16px 12px 30px;
    }
  }
  @media print {
    body { padding: 20px; font-size: 10pt; max-width: 100%; }
    .no-print, nav { display: none; }
    a { color: var(--text); text-decoration: none; }
    h1 { font-size: 16pt; }
    h2 { font-size: 13pt; break-after: avoid; }
    .pub-entry { break-inside: avoid; }
    .year-divider { break-after: avoid; }
  }

  .page-header {
    background-image: url('images/header.png');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    margin: -40px -24px 40px -24px;
    padding: 40px 24px;
    position: relative;
  }
  @media (max-width: 768px) {
    .page-header {
      margin: -20px -16px 20px -16px;
      padding: 20px 16px;
    }
  }
  @media (max-width: 480px) {
    .page-header {
      margin: -16px -12px 16px -12px;
      padding: 16px 12px;
    }
  }
  .page-header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(255, 255, 255, 0.95);
    z-index: -1;
  }
  .page-header > * {
    position: relative;
    z-index: 1;
  }

  h1 {
    font-size: 32px;
    color: var(--tudelft-darker);
    margin-bottom: 12px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 40px;
  }
  @media (max-width: 768px) {
    h1 {
      font-size: 26px;
      flex-direction: column;
      text-align: center;
      gap: 20px;
    }
  }
  @media (max-width: 480px) {
    h1 {
      font-size: 22px;
      gap: 16px;
    }
  }
  .badge {
    display: block;
    flex-shrink: 0;
    padding: 20px;
    background: var(--tudelft-light);
    border-radius: 8px;
  }
  .badge img {
    height: 120px;
    width: auto;
    display: block;
  }
  @media (max-width: 768px) {
    .badge {
      padding: 16px;
    }
    .badge img {
      height: 80px;
    }
  }
  @media (max-width: 480px) {
    .badge {
      padding: 12px;
    }
    .badge img {
      height: 60px;
    }
  }

  .subtitle {
    font-size: 20px;
    color: var(--text-secondary);
    margin-bottom: 20px;
  }

  .nav-bar {
    background: var(--tudelft-blue);
    color: #fff;
    padding: 12px 24px;
    margin: -40px -24px 30px -24px;
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    align-items: center;
  }
  @media (max-width: 768px) {
    .nav-bar {
      margin: -20px -16px 20px -16px;
      padding: 10px 16px;
      gap: 12px;
    }
  }
  @media (max-width: 480px) {
    .nav-bar {
      margin: -16px -12px 12px -12px;
      padding: 8px 12px;
      gap: 8px;
      font-size: 13px;
    }
  }
  .nav-bar a {
    color: #fff;
    text-decoration: none;
    font-weight: bold;
    transition: opacity 0.2s;
    padding: 4px 8px;
  }
  .nav-bar a:hover {
    opacity: 0.8;
    text-decoration: underline;
  }
  .nav-bar span {
    color: rgba(255, 255, 255, 0.6);
    font-weight: bold;
  }

  /* NAV */
  nav {
    position: sticky;
    top: 0;
    background: var(--tudelft-darker);
    margin: -40px -24px 32px;
    padding: 0 24px;
    z-index: 100;
    display: flex;
    flex-wrap: wrap;
    gap: 0;
  }
  nav a {
    color: #fff;
    text-decoration: none;
    padding: 12px 16px;
    font-size: 14px;
    font-weight: 500;
    transition: background .2s;
    white-space: nowrap;
  }
  nav a:hover { background: var(--tudelft-dark); }
  nav a.active { background: var(--tudelft-blue); }

  .content-section {
    margin-bottom: 40px;
  }

  h2 {
    font-size: 24px;
    color: var(--tudelft-darker);
    margin: 30px 0 16px 0;
    padding-bottom: 8px;
    border-bottom: 2px solid var(--tudelft-blue);
  }
  h2 .section-letter {
    display: inline-block;
    background: var(--tudelft-blue);
    color: #fff;
    width: 32px;
    height: 32px;
    line-height: 32px;
    text-align: center;
    border-radius: 4px;
    font-size: 16px;
    margin-right: 8px;
    vertical-align: middle;
  }

  .description-text {
    font-size: 15px;
    color: var(--text);
    line-height: 1.8;
    margin-bottom: 24px;
    max-width: 900px;
  }

  .social-links {
    display: flex;
    gap: 16px;
    margin: 20px 0 30px 0;
    flex-wrap: wrap;
  }
  .social-links a {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 50px;
    height: 50px;
    background: var(--tudelft-blue);
    color: #fff;
    text-decoration: none;
    border-radius: 50%;
    font-weight: bold;
    font-size: 20px;
    transition: background 0.2s, transform 0.2s;
  }
  .social-links a:hover {
    background: var(--tudelft-dark);
    transform: scale(1.1);
  }

  .two-column {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
    align-items: start;
    margin: 20px 0 30px 0;
  }
  .about-grid {
    display: grid;
    grid-template-columns: 6.5fr 3fr 0.5fr;
    gap: 20px;
    align-items: start;
    margin: 20px 0 30px 0;
  }
  @media (max-width: 1024px) {
    .about-grid {
      grid-template-columns: 6fr 3fr 1fr;
    }
  }
  @media (max-width: 768px) {
    .two-column,
    .about-grid {
      grid-template-columns: 1fr;
      gap: 20px;
    }
  }

  .group-photo {
    background: var(--tudelft-lightest);
    border: 2px dashed var(--border);
    border-radius: 8px;
    aspect-ratio: 4 / 3;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    font-size: 18px;
    text-align: center;
    padding: 20px;
  }
  .group-photo img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 6px;
  }

  .news-box {
    background: var(--tudelft-lightest);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 20px;
    max-height: 400px;
    overflow-y: auto;
  }
  .news-box h3 {
    color: var(--tudelft-dark);
    font-size: 18px;
    margin-bottom: 16px;
    padding-bottom: 8px;
    border-bottom: 2px solid var(--tudelft-blue);
  }
  .news-item {
    margin-bottom: 16px;
    padding-bottom: 16px;
    border-bottom: 1px solid var(--border);
  }
  .news-item:last-child {
    border-bottom: none;
    margin-bottom: 0;
    padding-bottom: 0;
  }
  .news-date {
    color: var(--tudelft-blue);
    font-weight: 600;
    font-size: 13px;
    margin-bottom: 4px;
  }
  .news-title {
    color: var(--text);
    font-weight: 500;
    margin-bottom: 4px;
  }

  .gallery-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 16px;
    margin: 20px 0;
  }
  @media (max-width: 768px) {
    .gallery-grid {
      grid-template-columns: repeat(3, 1fr);
      gap: 12px;
    }
  }
  @media (max-width: 480px) {
    .gallery-grid {
      grid-template-columns: repeat(2, 1fr);
      gap: 10px;
    }
  }

  .gallery-item {
    background: var(--tudelft-lightest);
    border: 2px dashed var(--border);
    border-radius: 8px;
    aspect-ratio: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s, background 0.2s;
    color: var(--text-secondary);
    text-align: center;
    padding: 12px;
    font-size: 13px;
  }
  .gallery-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 166, 214, 0.2);
    background: var(--tudelft-light);
  }
  a.gallery-item {
    color: var(--text-secondary);
    text-decoration: none;
  }
  a.gallery-item:hover {
    color: var(--tudelft-dark);
  }
  .gallery-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 6px;
  }

  .gallery-label {
    font-size: 12px;
    font-weight: 500;
    color: var(--tudelft-darker);
    margin-top: 8px;
  }

  .section-description {
    font-size: 13px;
    color: var(--text-secondary);
    margin-bottom: 16px;
  }

  .contact-box {
    background: var(--tudelft-lightest);
    border: 1px solid var(--border);
    border-left: 4px solid var(--tudelft-blue);
    border-radius: 8px;
    padding: 20px;
    font-size: 13px;
    line-height: 1.7;
  }
  .contact-box h3 {
    color: var(--tudelft-dark);
    font-size: 16px;
    margin-bottom: 12px;
    font-weight: 600;
  }
  .contact-box p {
    margin: 0 0 12px 0;
    color: var(--text);
  }
  .contact-box .contact-title {
    font-weight: 600;
    color: var(--tudelft-darker);
    margin-top: 14px;
    margin-bottom: 6px;
    font-size: 13px;
  }
  .contact-box .contact-title:first-of-type {
    margin-top: 0;
  }
  .contact-box a {
    color: var(--tudelft-blue);
    text-decoration: none;
  }
  .contact-box a:hover {
    text-decoration: underline;
  }

  header { border-bottom: 4px solid var(--tudelft-blue); padding-bottom: 20px; margin-bottom: 32px; }
  h1 { font-size: 28px; color: var(--tudelft-darker); margin-bottom: 4px; }
  h1 span { font-weight: 400; font-size: 18px; color: var(--text-secondary); }
  .header-subtitle { font-size: 22px; font-weight: 600; color: var(--tudelft-dark); margin-bottom: 12px; }
  .ids { font-size: 14px; color: var(--text-secondary); line-height: 1.8; }
  .ids a { color: var(--tudelft-dark); text-decoration: none; }
  .ids a:hover { text-decoration: underline; }
  .metrics { margin-top: 16px; padding: 16px 20px; background: var(--tudelft-light); border-left: 4px solid var(--tudelft-blue); border-radius: 0 6px 6px 0; font-size: 15px; }
  .metrics strong { color: var(--tudelft-darker); }
  .journal-table { margin-top: 16px; width: 100%; border-collapse: collapse; font-size: 14px; }
  .journal-table td { padding: 4px 10px; border-bottom: 1px solid #eee; }
  .journal-table td:nth-child(even) { font-weight: 600; text-align: center; width: 40px; color: var(--tudelft-dark); }
  h2 { font-size: 20px; color: var(--tudelft-darker); margin-top: 40px; margin-bottom: 16px; padding-bottom: 8px; border-bottom: 2px solid var(--tudelft-blue); scroll-margin-top: 60px; }
  h2 .section-letter { display: inline-block; background: var(--tudelft-blue); color: #fff; width: 28px; height: 28px; line-height: 28px; text-align: center; border-radius: 4px; font-size: 15px; margin-right: 8px; vertical-align: middle; }
  .year-divider { font-size: 17px; font-weight: 700; color: var(--tudelft-dark); background: var(--year-bg); padding: 6px 14px; margin: 20px 0 10px; border-radius: 4px; }
  .pub-entry { display: flex; gap: 12px; padding: 8px 0; border-bottom: 1px solid #f0f0f0; font-size: 14.5px; }
  .pub-entry:last-child { border-bottom: none; }
  .pub-num { flex-shrink: 0; width: 36px; font-weight: 700; color: var(--tudelft-dark); text-align: right; padding-top: 1px; }
  .pub-content { flex: 1; }
  .pub-content em { font-style: italic; }
  .pub-content a { color: var(--tudelft-dark); text-decoration: none; word-break: break-all; }
  .pub-content a:hover { text-decoration: underline; }
  .pub-note { display: inline-block; font-size: 12px; background: var(--tudelft-light); color: var(--tudelft-dark); padding: 1px 7px; border-radius: 3px; margin-left: 4px; font-weight: 600; }
  .pub-entry.highlighted { background: var(--highlight-bg); border-left: 4px solid var(--highlight-border); padding: 12px; margin: 4px 0; border-radius: 0 6px 6px 0; border-bottom: none; }
  .pub-entry.highlighted .pub-num { color: var(--tudelft-blue); font-size: 16px; }
  .toc-image { margin-top: 10px; max-width: 360px; border: 1px solid #dde8ed; border-radius: 4px; overflow: hidden; background: #f5f5f5; }
  .toc-image img { display: block; width: 100%; height: auto; }
  .toc-image img.broken { display: none; }
  .patent-entry, .book-entry, .thesis-entry, .talk-entry { padding: 10px 0; border-bottom: 1px solid #f0f0f0; font-size: 14.5px; }
  .patent-entry:last-child, .book-entry:last-child, .thesis-entry:last-child, .talk-entry:last-child { border-bottom: none; }
  .talk-entry .talk-title { font-style: italic; }
  .talk-entry .talk-type { font-weight: 600; color: var(--tudelft-dark); }
  .talk-entry .talk-venue { color: var(--text-secondary); }
  .conf-entry { padding: 6px 0; border-bottom: 1px solid #f0f0f0; font-size: 14px; }

  /* COVER GALLERY — 4 per row, A4 portrait ratio */
  .cover-gallery-grid {
    grid-template-columns: repeat(4, 1fr);
  }
  .cover-gallery-grid .gallery-item {
    aspect-ratio: 210 / 297;
    flex-direction: column;
    align-items: stretch;
    justify-content: flex-start;
    padding: 0;
    overflow: hidden;
    border: 1px solid var(--border);
    background: #fff;
  }
  .cover-gallery-grid .gallery-item > a {
    flex: 1;
    display: block;
    overflow: hidden;
    min-height: 0;
  }
  .cover-gallery-grid .gallery-image {
    width: 100%;
    height: 100%;
    object-fit: contain;
    display: block;
    border-radius: 0;
  }
  .gallery-caption {
    flex-shrink: 0;
    padding: 8px 10px;
    border-top: 1px solid var(--border);
    background: var(--tudelft-lightest);
    line-height: 1.4;
  }
  .gallery-caption h3 {
    font-size: 12px;
    font-weight: 700;
    color: var(--tudelft-darker);
    margin: 0 0 2px 0;
  }
  .gallery-caption p {
    font-size: 11.5px;
    color: var(--text-secondary);
    margin: 0;
  }
  .gallery-caption a {
    color: var(--tudelft-blue);
    text-decoration: none;
  }
  .gallery-caption a:hover { text-decoration: underline; }
  @media (max-width: 900px) {
    .cover-gallery-grid { grid-template-columns: repeat(3, 1fr); }
  }
  @media (max-width: 600px) {
    .cover-gallery-grid { grid-template-columns: repeat(2, 1fr); }
  }