/* ============================================================
   MAIN STYLESHEET - arnaboldiluca.eu
   Minimalistic academic website with dark/light mode
   ============================================================ */

/* --- Custom Properties --- */
:root {
  --color-bg: #ffffff;
  --color-bg-alt: #f8f9fa;
  --color-bg-code: #f4f4f5;
  --color-text: #1a1a2e;
  --color-text-secondary: #555;
  --color-text-muted: #888;
  --color-accent: #2B7551;
  --color-accent-hover: #1e5a3d;
  --color-accent-light: rgba(43, 117, 81, 0.1);
  --color-border: #e5e7eb;
  --color-card-bg: #ffffff;
  --color-card-shadow: rgba(0, 0, 0, 0.06);
  --color-nav-bg: rgba(255, 255, 255, 0.95);
  --color-nav-shadow: rgba(0, 0, 0, 0.05);
  --color-tag-bg: #e9ecef;
  --color-tag-text: #495057;
  --color-tag-active-bg: var(--color-accent);
  --color-tag-active-text: #ffffff;
  --color-timeline-line: #dee2e6;
  --color-bibtex-bg: #f8f9fa;
  --color-footer-bg: #f8f9fa;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Consolas', monospace;
  --container-max: 960px;
  --transition: 0.25s ease;
}

[data-theme="dark"] {
  --color-bg: #0f172a;
  --color-bg-alt: #1e293b;
  --color-bg-code: #1e293b;
  --color-text: #e2e8f0;
  --color-text-secondary: #94a3b8;
  --color-text-muted: #64748b;
  --color-accent: #4ecca3;
  --color-accent-hover: #6ee6bd;
  --color-accent-light: rgba(78, 204, 163, 0.12);
  --color-border: #334155;
  --color-card-bg: #1e293b;
  --color-card-shadow: rgba(0, 0, 0, 0.3);
  --color-nav-bg: rgba(15, 23, 42, 0.95);
  --color-nav-shadow: rgba(0, 0, 0, 0.2);
  --color-tag-bg: #334155;
  --color-tag-text: #cbd5e1;
  --color-tag-active-bg: var(--color-accent);
  --color-tag-active-text: #0f172a;
  --color-timeline-line: #334155;
  --color-bibtex-bg: #1e293b;
  --color-footer-bg: #0c1222;
}

/* --- Base / Reset --- */
*, *::before, *::after { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
}

body {
  margin: 0;
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
  color: var(--color-text);
  background-color: var(--color-bg);
  transition: background-color var(--transition), color var(--transition);
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; height: auto; }
a { color: var(--color-accent); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--color-accent-hover); }

/* --- Typography --- */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.3;
  color: var(--color-text);
  margin-top: 0;
}
h1 { font-size: 2rem; margin-bottom: 1rem; }
h2 { font-size: 1.5rem; margin-bottom: 0.75rem; }
h3 { font-size: 1.25rem; margin-bottom: 0.5rem; }
h4 { font-size: 1.1rem; margin-bottom: 0.5rem; }

.page-title {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.page-subtitle {
  color: var(--color-text-secondary);
  font-size: 1.1rem;
  margin-bottom: 2rem;
}

.lead { font-size: 1.1rem; color: var(--color-text-secondary); }

/* --- Layout --- */
.site-container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.section { padding: 3rem 0; }
.section + .section { border-top: 1px solid var(--color-border); }

/* --- Navbar --- */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--color-nav-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  box-shadow: 0 1px 3px var(--color-nav-shadow);
  transition: background-color var(--transition), border-color var(--transition);
}

.site-nav .navbar-brand {
  font-weight: 700;
  font-size: 1.2rem;
  color: var(--color-text);
  letter-spacing: -0.02em;
}
.site-nav .navbar-brand:hover { color: var(--color-accent); }

.site-nav .nav-link {
  color: var(--color-text-secondary);
  font-size: 0.9rem;
  font-weight: 500;
  padding: 0.5rem 0.75rem !important;
  transition: color var(--transition);
}
.site-nav .nav-link:hover,
.site-nav .nav-link.active {
  color: var(--color-accent);
}

.theme-toggle {
  background: none;
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: 0.4rem 0.6rem;
  cursor: pointer;
  color: var(--color-text-secondary);
  font-size: 1rem;
  transition: all var(--transition);
  display: flex;
  align-items: center;
}
.theme-toggle:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

.navbar-toggler {
  border: 1px solid var(--color-border);
  padding: 0.4rem 0.6rem;
}
.navbar-toggler:focus { box-shadow: none; }
.navbar-toggler-icon {
  background-image: none;
  width: 1.2em;
  height: 1.2em;
  display: flex;
  align-items: center;
  justify-content: center;
}
.navbar-toggler-icon::before {
  content: '\f0c9';
  font-family: 'Font Awesome 6 Free';
  font-weight: 900;
  color: var(--color-text-secondary);
  font-size: 1rem;
}

/* --- Hero Section (Homepage) --- */
.hero {
  padding: 4rem 0 2rem;
}

.hero-content {
  display: flex;
  align-items: flex-start;
  gap: 3rem;
}

.hero-photo {
  flex-shrink: 0;
}

.hero-photo img {
  width: 220px;
  height: 220px;
  border-radius: 50%;
  object-fit: cover;
  border: 3px solid var(--color-accent);
  box-shadow: 0 4px 20px var(--color-card-shadow);
}

.hero-text h1 {
  font-size: 2.2rem;
  margin-bottom: 0.25rem;
  letter-spacing: -0.02em;
}

.hero-tagline {
  color: var(--color-text-secondary);
  font-size: 1.1rem;
  margin-bottom: 0.75rem;
}

.hero-affiliation {
  color: var(--color-text-muted);
  font-size: 0.95rem;
  margin-bottom: 1rem;
}

.role-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1.25rem;
}

.role-badge {
  display: inline-block;
  padding: 0.25rem 0.75rem;
  border: 1px solid var(--color-accent);
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--color-accent);
  background: var(--color-accent-light);
}

.hero-social {
  display: flex;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.hero-social a {
  color: var(--color-text-muted);
  font-size: 1.3rem;
  transition: color var(--transition), transform var(--transition);
}
.hero-social a:hover {
  color: var(--color-accent);
  transform: translateY(-2px);
}

.hero-bio {
  color: var(--color-text-secondary);
  line-height: 1.8;
}

@media (max-width: 768px) {
  .hero-content {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }
  .hero-text h1 { font-size: 1.8rem; }
  .role-badges { justify-content: center; }
  .hero-social { justify-content: center; }
}

/* --- Cards --- */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1.5rem;
}

.card-item {
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: 12px;
  padding: 1.5rem;
  transition: all var(--transition);
}
.card-item:hover {
  box-shadow: 0 4px 16px var(--color-card-shadow);
  transform: translateY(-2px);
}

.card-item img {
  width: 100%;
  height: 140px;
  object-fit: contain;
  border-radius: 8px;
  margin-bottom: 1rem;
  background: var(--color-bg-alt);
  padding: 0.5rem;
}

.card-item h3 { font-size: 1.1rem; margin-bottom: 0.5rem; }
.card-item p { font-size: 0.9rem; color: var(--color-text-secondary); margin-bottom: 1rem; }

.card-link {
  display: inline-block;
  padding: 0.35rem 1rem;
  border: 1px solid var(--color-accent);
  border-radius: 6px;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--color-accent);
  transition: all var(--transition);
}
.card-link:hover {
  background: var(--color-accent);
  color: #fff;
}

/* --- Publications --- */
.pub-filters {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 2rem;
  align-items: center;
}

.pub-filter-tag {
  display: inline-block;
  padding: 0.3rem 0.85rem;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 500;
  background: var(--color-tag-bg);
  color: var(--color-tag-text);
  cursor: pointer;
  border: none;
  transition: all var(--transition);
}
.pub-filter-tag:hover {
  background: var(--color-accent-light);
  color: var(--color-accent);
}
.pub-filter-tag.active {
  background: var(--color-tag-active-bg);
  color: var(--color-tag-active-text);
}

.pub-export-btn {
  margin-left: auto;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.4rem 1rem;
  border: 1px solid var(--color-accent);
  border-radius: 8px;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--color-accent);
  background: transparent;
  cursor: pointer;
  transition: all var(--transition);
}
.pub-export-btn:hover {
  background: var(--color-accent);
  color: #fff;
}

.pub-year-heading {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--color-text);
  margin-top: 2rem;
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--color-accent);
  display: inline-block;
}

.pub-item {
  padding: 1.25rem 0;
  border-bottom: 1px solid var(--color-border);
  transition: opacity var(--transition);
}
.pub-item:last-child { border-bottom: none; }
.pub-item.hidden { display: none; }

.pub-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 0.3rem;
  line-height: 1.5;
}

.pub-authors {
  font-size: 0.88rem;
  color: var(--color-text-secondary);
  margin-bottom: 0.25rem;
}

.pub-venue {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  font-style: italic;
  margin-bottom: 0.5rem;
}

.pub-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.pub-link-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  padding: 0.25rem 0.65rem;
  border-radius: 6px;
  font-size: 0.78rem;
  font-weight: 500;
  border: 1px solid var(--color-border);
  color: var(--color-text-secondary);
  background: transparent;
  cursor: pointer;
  text-decoration: none;
  transition: all var(--transition);
}
.pub-link-btn:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

.pub-bibtex {
  display: none;
  margin-top: 0.75rem;
  background: var(--color-bibtex-bg);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: 1rem;
  position: relative;
}
.pub-bibtex.show { display: block; }

.pub-bibtex pre {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  line-height: 1.5;
  white-space: pre-wrap;
  word-break: break-all;
  color: var(--color-text-secondary);
}

.pub-bibtex .copy-btn {
  position: absolute;
  top: 0.5rem;
  right: 0.5rem;
  padding: 0.2rem 0.6rem;
  border-radius: 4px;
  font-size: 0.75rem;
  border: 1px solid var(--color-border);
  background: var(--color-bg);
  color: var(--color-text-muted);
  cursor: pointer;
  transition: all var(--transition);
}
.pub-bibtex .copy-btn:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

.pub-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin-top: 0.5rem;
}

.pub-tag {
  font-size: 0.7rem;
  padding: 0.15rem 0.5rem;
  border-radius: 10px;
  background: var(--color-accent-light);
  color: var(--color-accent);
  font-weight: 500;
}

/* --- CV Timeline --- */
.timeline {
  position: relative;
  padding: 2rem 0;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 50%;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--color-timeline-line);
  transform: translateX(-50%);
}

.timeline-section-title {
  text-align: center;
  margin: 3rem 0 2rem;
  position: relative;
  z-index: 1;
}

.timeline-section-title span {
  background: var(--color-bg);
  padding: 0.5rem 1.5rem;
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--color-accent);
  border: 2px solid var(--color-accent);
  border-radius: 30px;
  display: inline-block;
  transition: background-color var(--transition);
}

.timeline-entry {
  position: relative;
  width: 50%;
  padding: 0 2.5rem 2rem;
}

.timeline-entry.left {
  left: 0;
  text-align: right;
  padding-right: 2.5rem;
  padding-left: 0;
}

.timeline-entry.right {
  left: 50%;
  text-align: left;
  padding-left: 2.5rem;
  padding-right: 0;
}

.timeline-marker {
  position: absolute;
  top: 0.5rem;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--color-accent);
  border: 3px solid var(--color-bg);
  box-shadow: 0 0 0 2px var(--color-accent);
  z-index: 1;
  transition: background-color var(--transition), border-color var(--transition);
}

.timeline-entry.left .timeline-marker { right: -7px; }
.timeline-entry.right .timeline-marker { left: -7px; }

.timeline-content {
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: 10px;
  padding: 1.25rem;
  transition: all var(--transition);
}
.timeline-content:hover {
  box-shadow: 0 4px 12px var(--color-card-shadow);
}

.timeline-date {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--color-accent);
  margin-bottom: 0.3rem;
}

.timeline-content h3 {
  font-size: 1rem;
  margin-bottom: 0.2rem;
}

.timeline-content h4 {
  font-size: 0.88rem;
  font-weight: 400;
  color: var(--color-text-secondary);
  margin-bottom: 0.5rem;
}

.timeline-content p {
  font-size: 0.85rem;
  color: var(--color-text-secondary);
  margin-bottom: 0;
}

.timeline-content ul {
  font-size: 0.85rem;
  color: var(--color-text-secondary);
  padding-left: 1.2rem;
  margin-bottom: 0;
}

@media (max-width: 768px) {
  .timeline::before { left: 20px; }

  .timeline-entry {
    width: 100%;
    left: 0 !important;
    text-align: left !important;
    padding-left: 3rem !important;
    padding-right: 0 !important;
  }

  .timeline-marker {
    left: 13px !important;
    right: auto !important;
  }

  .timeline-section-title { text-align: left; padding-left: 3rem; }
}

/* --- News --- */
.news-year { font-size: 1.3rem; font-weight: 700; margin-top: 2rem; margin-bottom: 1rem; color: var(--color-text); }

.news-item {
  display: flex;
  gap: 1rem;
  padding: 0.75rem 0;
  border-bottom: 1px solid var(--color-border);
  align-items: baseline;
}
.news-item:last-child { border-bottom: none; }

.news-date {
  flex-shrink: 0;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-accent);
  min-width: 80px;
}

.news-text {
  font-size: 0.95rem;
  color: var(--color-text-secondary);
}
.news-text a { font-weight: 500; }

/* --- Teaching --- */
.teaching-card {
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: 12px;
  padding: 1.5rem;
  margin-bottom: 1.5rem;
  transition: all var(--transition);
}

.teaching-card h3 {
  font-size: 1.1rem;
  margin-bottom: 0.3rem;
}

.teaching-meta {
  font-size: 0.88rem;
  color: var(--color-text-muted);
  margin-bottom: 0.75rem;
}

.teaching-rating {
  display: inline-block;
  padding: 0.2rem 0.6rem;
  border-radius: 6px;
  font-size: 0.78rem;
  font-weight: 600;
  background: var(--color-accent-light);
  color: var(--color-accent);
}

.teaching-feedback {
  background: var(--color-bg-alt);
  border-left: 3px solid var(--color-accent);
  padding: 0.75rem 1rem;
  margin-top: 0.75rem;
  border-radius: 0 8px 8px 0;
}

.teaching-feedback blockquote {
  font-size: 0.88rem;
  font-style: italic;
  color: var(--color-text-secondary);
  margin: 0.4rem 0;
}

.teaching-feedback cite {
  font-size: 0.78rem;
  color: var(--color-text-muted);
  font-style: normal;
  font-weight: 600;
}

/* --- Projects --- */
.project-card {
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: 12px;
  padding: 1.5rem;
  margin-bottom: 1.5rem;
  transition: all var(--transition);
}
.project-card:hover {
  box-shadow: 0 4px 12px var(--color-card-shadow);
}

.project-card h3 { font-size: 1.1rem; }

.project-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-bottom: 0.75rem;
}

.difficulty-badge {
  font-size: 0.75rem;
  padding: 0.2rem 0.6rem;
  border-radius: 6px;
  font-weight: 600;
}
.difficulty-badge.high { background: #fef3c7; color: #92400e; }
.difficulty-badge.very-high { background: #fee2e2; color: #991b1b; }
[data-theme="dark"] .difficulty-badge.high { background: rgba(254, 243, 199, 0.15); color: #fbbf24; }
[data-theme="dark"] .difficulty-badge.very-high { background: rgba(254, 226, 226, 0.15); color: #f87171; }

.topic-badge {
  font-size: 0.75rem;
  padding: 0.2rem 0.6rem;
  border-radius: 6px;
  font-weight: 500;
  background: var(--color-accent-light);
  color: var(--color-accent);
}

.industry-badge {
  font-size: 0.75rem;
  padding: 0.2rem 0.6rem;
  border-radius: 6px;
  font-weight: 500;
  background: #dbeafe;
  color: #1e40af;
}
[data-theme="dark"] .industry-badge { background: rgba(219, 234, 254, 0.12); color: #60a5fa; }

.project-details {
  margin-top: 0.75rem;
}

.project-details summary {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-accent);
  cursor: pointer;
  margin-bottom: 0.5rem;
}

.project-details ul {
  font-size: 0.88rem;
  color: var(--color-text-secondary);
  padding-left: 1.2rem;
}

/* --- Blog --- */
.blog-post-preview {
  padding: 1.5rem 0;
  border-bottom: 1px solid var(--color-border);
}

.blog-post-preview h2 {
  margin-bottom: 0.25rem;
}
.blog-post-preview h2 a {
  color: var(--color-text);
  transition: color var(--transition);
}
.blog-post-preview h2 a:hover { color: var(--color-accent); }

.blog-post-preview .post-subtitle {
  font-size: 1rem;
  color: var(--color-text-secondary);
  font-weight: 400;
  margin-bottom: 0.5rem;
}

.blog-post-preview .post-meta {
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

/* Blog article page */
.blog-article {
  max-width: 720px;
  margin: 0 auto;
}

.blog-article h1 { font-size: 2rem; margin-bottom: 0.25rem; }
.blog-article h2 { font-size: 1.3rem; color: var(--color-text-secondary); font-weight: 400; margin-bottom: 1.5rem; }

.blog-article p {
  font-size: 1.05rem;
  line-height: 1.85;
  margin-bottom: 1.25rem;
}

.blog-article blockquote {
  border-left: 4px solid var(--color-accent);
  padding: 1rem 1.5rem;
  margin: 1.5rem 0;
  background: var(--color-bg-alt);
  border-radius: 0 8px 8px 0;
  font-style: italic;
  font-size: 1.1rem;
  color: var(--color-text-secondary);
}

.blog-article figure {
  margin: 2rem 0;
  text-align: center;
}

.blog-article figure img {
  max-width: 100%;
  border-radius: 8px;
  box-shadow: 0 4px 12px var(--color-card-shadow);
}

.blog-article figcaption {
  margin-top: 0.5rem;
  font-size: 0.85rem;
  color: var(--color-text-muted);
  font-style: italic;
}

/* --- Footer --- */
.site-footer {
  background: var(--color-footer-bg);
  border-top: 1px solid var(--color-border);
  padding: 2rem 0;
  margin-top: 3rem;
  text-align: center;
  transition: background-color var(--transition), border-color var(--transition);
}

.footer-social {
  display: flex;
  justify-content: center;
  gap: 1.25rem;
  margin-bottom: 1rem;
}

.footer-social a {
  color: var(--color-text-muted);
  font-size: 1.2rem;
  transition: color var(--transition), transform var(--transition);
}
.footer-social a:hover {
  color: var(--color-accent);
  transform: translateY(-2px);
}

.site-footer p {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  margin: 0;
}

/* --- CV Download Button --- */
.cv-download {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.6rem 1.5rem;
  border: 2px solid var(--color-accent);
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--color-accent);
  transition: all var(--transition);
}
.cv-download:hover {
  background: var(--color-accent);
  color: #fff;
}

/* --- Animations --- */
.animate-on-scroll {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.animate-on-scroll.visible {
  opacity: 1;
  transform: translateY(0);
}

/* --- Accordion overrides --- */
.accordion-button {
  background: var(--color-card-bg);
  color: var(--color-text);
  font-weight: 600;
  border: none;
  box-shadow: none !important;
}
.accordion-button:not(.collapsed) {
  background: var(--color-accent-light);
  color: var(--color-accent);
}
.accordion-button::after {
  filter: var(--color-text-muted);
}
.accordion-item {
  background: var(--color-card-bg);
  border-color: var(--color-border);
}
.accordion-body {
  background: var(--color-card-bg);
  color: var(--color-text-secondary);
}

/* --- Utility --- */
.text-accent { color: var(--color-accent); }
.bg-accent-light { background: var(--color-accent-light); }
.mt-0 { margin-top: 0; }
.mb-0 { margin-bottom: 0; }

/* --- Responsive --- */
@media (max-width: 576px) {
  .page-title { font-size: 1.6rem; }
  .section { padding: 2rem 0; }
  .card-grid { grid-template-columns: 1fr; }
  .pub-filters { gap: 0.35rem; }
  .pub-export-btn { margin-left: 0; margin-top: 0.5rem; width: 100%; justify-content: center; }
  .news-item { flex-direction: column; gap: 0.25rem; }
  .news-date { min-width: auto; }
}