/* =========================================================
   TOKENS
   ========================================================= */

@import url('https://fonts.googleapis.com/css2?family=Fraunces:opsz,wght@9..144,400;9..144,500;9..144,600;9..144,700&family=Inter:wght@400;500;600&family=IBM+Plex+Mono:wght@400;500&display=swap');

:root {
  --ink: #1c2b39;
  --ink-soft: #4a5a68;
  --paper: #fbfaf7;
  --paper-raised: #f5f3ee;
  --line: #ddd8cd;
  --signal: #2f6f6b;      /* teal accent — primary */
  --signal-dark: #1f4d4a;
  --amber: #b9812c;       /* warm accent — sparing use */
  --font-display: "Fraunces", Georgia, serif;
  --font-body: "Inter", "Segoe UI", Helvetica, Arial, sans-serif;
  --font-mono: "IBM Plex Mono", "SFMono-Regular", Menlo, monospace;
}

/* =========================================================
   GENERAL
   ========================================================= */

body {
  font-family: var(--font-body);
  line-height: 1.7;
  font-size: 17px;
  color: var(--ink);
  background-color: var(--paper);
}

main.content {
  max-width: 1100px;
  margin: auto;
  padding: 2rem;
}

#TOC {
  position: sticky;
  top: 100px;
  max-height: 80vh;
  overflow-y: auto;
}

/* =========================================================
   NAVBAR
   ========================================================= */

.navbar {
  background-color: var(--paper) !important;
  border-bottom: 1px solid var(--line);
}

.navbar-title,
.navbar-brand {
  font-family: var(--font-display);
  font-weight: 600;
  color: var(--ink) !important;
  letter-spacing: 0.01em;
}

.navbar .nav-link {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  letter-spacing: 0.02em;
  text-transform: uppercase;
  color: var(--ink-soft) !important;
  position: relative;
}

.navbar .nav-link:hover {
  color: var(--signal-dark) !important;
}

.navbar .nav-link.active {
  color: var(--ink) !important;
}

/* =========================================================
   TITLE BLOCK
   ========================================================= */

.quarto-title-block .title {
  font-family: var(--font-display);
  font-size: 2.6rem;
  font-weight: 600;
  color: var(--ink);
}

.quarto-title-block .subtitle {
  font-family: var(--font-mono);
  font-size: 1rem;
  color: var(--signal-dark);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

/* =========================================================
   HEADINGS
   ========================================================= */

h1 {
  font-family: var(--font-display);
  font-size: 2.3rem;
  font-weight: 600;
  margin-bottom: 0.8rem;
  color: var(--ink);
}

h2 {
  font-family: var(--font-display);
  font-size: 1.7rem;
  font-weight: 600;
  margin-top: 2.8rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--line);
  color: var(--ink);
  position: relative;
}

/* coordinate-style eyebrow label before section headings */
h2::before {
  content: "§";
  font-family: var(--font-mono);
  color: var(--signal);
  margin-right: 0.5rem;
  font-weight: 500;
}

h3 {
  font-family: var(--font-display);
  font-size: 1.2rem;
  font-weight: 600;
  margin-top: 0.5rem;
  color: var(--ink);
}

/* =========================================================
   PARAGRAPHS & LINKS
   ========================================================= */

p {
  margin-bottom: 1rem;
  color: var(--ink);
}

a {
  color: var(--signal-dark);
  text-decoration: none;
  border-bottom: 1px solid var(--signal);
}

a:hover {
  color: var(--amber);
  border-bottom-color: var(--amber);
}

/* =========================================================
   HERO SECTION
   ========================================================= */

.hero {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 4rem;
  align-items: center;
  margin-top: 2.5rem;
  margin-bottom: 3rem;
  padding: 2.5rem 2rem;
  border-radius: 4px;
  position: relative;
  background-color: var(--paper-raised);
  background-image: radial-gradient(var(--line) 1px, transparent 1px);
  background-size: 18px 18px;
  border: 1px solid var(--line);
}

.hero-text {
  max-width: 650px;
}

.hero-text strong {
  color: var(--signal-dark);
}

.hero-image {
  text-align: center;
  color: var(--ink-soft);
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 2rem 1.5rem;
  box-shadow: 0 12px 30px rgba(28, 43, 57, 0.08);
}

.hero-image img {
  width: 260px;
  max-width: 100%;
  border-radius: 4px;
  margin-bottom: 1rem;
  filter: grayscale(15%);
}

/* =========================================================
   BUTTONS
   ========================================================= */

.btn {
  display: inline-block;
  padding: 0.65rem 1.2rem;
  margin-right: 0.6rem;
  margin-top: 1.2rem;
  border-radius: 3px;
  text-decoration: none;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  border: 1px solid transparent;
  transition: all 0.2s ease;
}

.btn-primary {
  background-color: var(--signal-dark);
  color: var(--paper) !important;
  border-color: var(--signal-dark);
}

.btn-primary:hover {
  background-color: var(--ink);
  border-color: var(--ink);
  color: var(--paper) !important;
  text-decoration: none;
}

.btn-secondary {
  border-color: var(--signal-dark);
  color: var(--signal-dark) !important;
  background-color: transparent;
}

.btn-secondary:hover {
  background-color: var(--paper-raised);
  text-decoration: none;
}

/* =========================================================
   CARD GRID
   ========================================================= */

.grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(280px, 1fr));
  gap: 1.2rem;
  margin-top: 1rem;
}

.card {
  border: 1px solid var(--line);
  border-top: 3px solid var(--signal);
  border-radius: 3px;
  padding: 1.3rem;
  background-color: var(--paper);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.card:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 20px rgba(28, 43, 57, 0.08);
}

.card h3 {
  margin-top: 0;
  margin-bottom: 0.6rem;
  font-size: 1.05rem;
}

/* =========================================================
   CODE
   ========================================================= */

pre {
  background-color: var(--paper-raised);
  border: 1px solid var(--line);
  padding: 1rem;
  border-radius: 4px;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 14px;
}

code {
  font-family: var(--font-mono);
  background-color: var(--paper-raised);
  padding: 2px 5px;
  border-radius: 3px;
}

/* =========================================================
   BLOCKQUOTE
   ========================================================= */

blockquote {
  border-left: 3px solid var(--signal);
  padding-left: 1rem;
  color: var(--ink-soft);
  margin: 1.5rem 0;
  font-style: italic;
}

/* =========================================================
   IMAGES
   ========================================================= */

img {
  max-width: 100%;
}

/* =========================================================
   FOOTER
   ========================================================= */

.nav-footer {
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--ink-soft);
}

/* =========================================================
   SIGNAL → HELIX ANIMATED GRAPHIC
   ========================================================= */

.hero-top-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: start;
  margin-top: 1rem;
}

.latest-articles-col h2 {
  margin-top: 0;
  padding-bottom: 0.4rem;
}

@media (max-width: 900px) {
  .hero-top-grid {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }
}

.signal-helix-wrap {
  margin-top: 1.5rem;
  margin-bottom: 0.5rem;
  padding: 1rem 0 0.5rem;
}

.signal-helix {
  width: 100%;
  height: auto;
  display: block;
}

.signal-helix .strand {
  fill: none;
  stroke-width: 2.5;
  stroke-linecap: round;
}

.signal-helix .strand-a {
  stroke: var(--signal);
}

.signal-helix .strand-b {
  stroke: var(--amber);
  opacity: 0;
  animation: helix-fade-in 1.5s ease-out 0.3s forwards;
}

.signal-helix .helix-rung {
  stroke: var(--ink-soft);
  stroke-width: 1.5;
  opacity: 0.25;
  animation: rung-pulse 3s ease-in-out infinite;
}

.signal-helix .pulse {
  fill: var(--amber);
}

@keyframes helix-fade-in {
  to { opacity: 1; }
}

@keyframes rung-pulse {
  0%, 100% { opacity: 0.2; }
  50% { opacity: 0.7; }
}

.signal-helix-caption {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--ink-soft);
  text-align: right;
  margin-top: 0.3rem;
  letter-spacing: 0.02em;
}

@media (prefers-reduced-motion: reduce) {
  .signal-helix .strand-b {
    animation: none;
    opacity: 1;
  }
  .signal-helix .helix-rung {
    animation: none;
    opacity: 0.5;
  }
  .signal-helix .pulse {
    display: none;
  }
}

/* =========================================================
   ICON CYCLE: physics -> code -> genome
   ========================================================= */

.icon-cycle-wrap {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.6rem;
  margin: 1rem 0 2rem;
}

.icon-cycle {
  position: relative;
  width: 88px;
  height: 88px;
}

.cycle-icon {
  position: absolute;
  top: 0;
  left: 0;
  width: 88px;
  height: 88px;
  opacity: 0;
  animation: icon-cycle-fade 9s infinite;
}

.icon-physics { animation-delay: 0s; }
.icon-code    { animation-delay: 3s; }
.icon-dna     { animation-delay: 6s; }

/* order of appearance: physics (0-3s), code (3-6s), dna (6-9s) */
@keyframes icon-cycle-fade {
  0%   { opacity: 0; transform: scale(0.85); }
  4%   { opacity: 1; transform: scale(1); }
  29%  { opacity: 1; transform: scale(1); }
  33%  { opacity: 0; transform: scale(0.85); }
  100% { opacity: 0; }
}

.icon-cycle-label {
  position: relative;
  height: 1.4rem;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--ink-soft);
}

.icon-cycle-label span {
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  opacity: 0;
  animation: icon-cycle-fade 9s infinite;
  white-space: nowrap;
}

.label-physics { animation-delay: 0s; }
.label-code    { animation-delay: 3s; }
.label-dna     { animation-delay: 6s; }

@media (prefers-reduced-motion: reduce) {
  .cycle-icon,
  .icon-cycle-label span {
    animation: none;
  }
  .icon-physics, .label-physics { opacity: 1; }
  .icon-code, .icon-dna, .label-code, .label-dna { display: none; }
}

/* =========================================================
   TECHNICAL SKILLS TAGS
   ========================================================= */

.skills-group {
  margin-bottom: 1.6rem;
}

.skills-group strong {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--signal-dark);
  margin-bottom: 0.6rem;
}

.tag-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  padding: 0.3rem 0.7rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  background-color: var(--paper-raised);
  color: var(--ink);
  white-space: nowrap;
  transition: border-color 0.15s ease, color 0.15s ease;
}

.tag:hover {
  border-color: var(--signal);
  color: var(--signal-dark);
}

/* =========================================================
   THESIS PAGE
   ========================================================= */

.thesis-hero-wrap {
  margin: 1rem 0 2rem;
  padding: 1.5rem;
  background-color: var(--paper-raised);
  border: 1px solid var(--line);
  border-radius: 4px;
}

.thesis-hero-art {
  width: 100%;
  height: auto;
  display: block;
}

.thesis-hero-caption {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--ink-soft);
  text-align: center;
  margin-top: 0.6rem;
  margin-bottom: 0;
}

.thesis-chapter {
  border-left: 3px solid var(--signal);
  padding: 0.2rem 0 0.2rem 1rem;
  margin-bottom: 1.4rem;
}

.thesis-chapter strong {
  display: block;
  font-family: var(--font-display);
  font-size: 1.05rem;
  color: var(--ink);
  margin-bottom: 0.3rem;
}

/* =========================================================
   LATEST TUTORIALS FEED (home page, auto-scrolling ticker)
   ========================================================= */

.tutorials-ticker {
  position: relative;
  height: 260px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 6px;
  background-color: var(--paper-raised);
  background-image: radial-gradient(var(--line) 1px, transparent 1px);
  background-size: 18px 18px;
  padding: 0.75rem;
  -webkit-mask-image: linear-gradient(to bottom, transparent 0, #000 6%, #000 94%, transparent 100%);
  mask-image: linear-gradient(to bottom, transparent 0, #000 6%, #000 94%, transparent 100%);
}

.ticker-track {
  animation: ticker-scroll 26s linear infinite;
}

.tutorials-ticker:hover .ticker-track {
  animation-play-state: paused;
}

@keyframes ticker-scroll {
  from { transform: translateY(0); }
  to   { transform: translateY(-50%); }
}

#latest-tutorials .quarto-post {
  display: flex;
  gap: 0.9rem;
  align-items: flex-start;
  border: 1px solid var(--line);
  border-left: 3px solid var(--signal);
  border-radius: 3px;
  padding: 0.8rem 1rem;
  margin-bottom: 0.7rem;
  background-color: var(--paper);
  transition: transform 0.15s ease, box-shadow 0.15s ease, border-color 0.15s ease;
}

#latest-tutorials .quarto-post:nth-child(3n+2) {
  border-left-color: var(--amber);
}

#latest-tutorials .quarto-post:hover {
  transform: translateX(4px);
  box-shadow: 0 6px 16px rgba(28, 43, 57, 0.08);
}

#latest-tutorials .thumbnail {
  flex: none;
  width: 64px;
  height: 64px;
  border-radius: 3px;
  overflow: hidden;
  background-color: var(--paper-raised);
  border: 1px solid var(--line);
}

#latest-tutorials .thumbnail img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

#latest-tutorials .body {
  flex: 1 1 auto;
  min-width: 0; /* allow title to wrap instead of overflowing the flex row */
}

#latest-tutorials .metadata {
  flex: none;
}

#latest-tutorials .metadata {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  margin-bottom: 0.4rem;
}

#latest-tutorials .metadata::before {
  content: "";
  display: inline-block;
  width: 6px;
  height: 6px;
  flex: none;
  border-radius: 50%;
  background-color: var(--signal);
}

#latest-tutorials .quarto-post:nth-child(3n+2) .metadata::before {
  background-color: var(--amber);
}

#latest-tutorials .listing-date,
#latest-tutorials .listing-categories {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--signal-dark);
}

#latest-tutorials .listing-title {
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--ink);
  margin: 0;
}

#latest-tutorials .listing-title a {
  color: var(--ink);
  text-decoration: none;
  border-bottom: none;
}

#latest-tutorials .listing-description {
  display: none; /* keep cards compact — title + eyebrow only */
}

@media (prefers-reduced-motion: reduce) {
  .tutorials-ticker {
    height: auto;
    overflow: visible;
    -webkit-mask-image: none;
    mask-image: none;
  }
  .ticker-track {
    animation: none;
  }
}

/* =========================================================
   MOBILE
   ========================================================= */

@media (max-width: 768px) {
  main.content {
    max-width: 100%;
    padding: 1.5rem;
  }

  .hero {
    grid-template-columns: 1fr;
    gap: 2rem;
    padding: 1.5rem;
  }

  .hero-text {
    max-width: 100%;
  }

  .hero-image {
    text-align: center;
  }

  .grid {
    grid-template-columns: 1fr;
  }
}

/* Respect reduced motion preference */
@media (prefers-reduced-motion: reduce) {
  .card,
  .btn,
  #latest-tutorials .quarto-post {
    transition: none;
  }
}