/* === Variables === */
:root {
  --bg-base:      #0D1117;
  --bg-surface:   #161B22;
  --bg-elevated:  #21262D;
  --border:       #30363D;
  --text-primary: #E6EDF3;
  --text-muted:   #8B949E;
  --accent-blue:   #58A6FF;
  --accent-green:  #3FB950;
  --accent-amber:  #D29922;
  --accent-violet: #A371F7;

  --font-sans: "IBM Plex Sans", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", "Fira Code", monospace;
  --max-width: 760px;
}

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

body {
  font-family: var(--font-sans);
  background: var(--bg-base);
  color: var(--text-primary);
  line-height: 1.7;
  padding: 0 1rem;
}

a { color: var(--accent-blue); text-decoration: none; }
a:hover { text-decoration: underline; }

code, pre {
  font-family: var(--font-mono);
  background: var(--bg-elevated);
}

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

.nav-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem 1.5rem;
}

.nav-logo, .site-title {
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--text-primary);
  letter-spacing: 0.02em;
}
.nav-logo:hover, .site-title:hover { color: var(--text-primary); text-decoration: none; }

.nav-links { list-style: none; display: flex; gap: 1.75rem; }
.nav-links a, .nav-link { color: var(--text-muted); font-size: 0.875rem; }
.nav-links a:hover, .nav-link:hover { color: var(--text-primary); text-decoration: none; }
.nav-links a.active, .nav-link.active { color: var(--accent-blue); }

main {
  max-width: var(--max-width);
  margin: 2.5rem auto;
}


/* === Typography === */
h1 { font-size: 2rem; line-height: 1.2; margin-bottom: 0.5rem; font-weight: 700; }
h2 { font-size: 1.2rem; font-weight: 600; margin: 2rem 0 0.75rem; }
h3 { font-size: 1rem; font-weight: 600; margin: 1.5rem 0 0.5rem; }
p  { margin-bottom: 1rem; }

.content h2 { font-size: 1.2rem; margin: 2rem 0 0.75rem; }
.content h3 { font-size: 1rem; margin: 1.5rem 0 0.5rem; }
.content ul, .content ol { padding-left: 1.5rem; margin-bottom: 1rem; }
.content li { margin-bottom: 0.3rem; }
.content pre { overflow-x: auto; margin: 1.5rem 0; border-radius: 4px; border: 0.5px solid var(--border); }
.content code { font-size: 0.875rem; }
.content p code { background: var(--bg-elevated); padding: 0.1em 0.3em; border-radius: 3px; font-size: 0.85em; }
.content blockquote {
  border-left: 2px solid var(--border);
  padding-left: 1rem;
  color: var(--text-muted);
  margin: 1rem 0;
}

/* === Tags / Pills === */
.tag {
  display: inline-block;
  padding: 2px 10px;
  border-radius: 20px;
  font-size: 11px;
  font-weight: 500;
  border: 0.5px solid;
  letter-spacing: 0.02em;
  font-family: var(--font-sans);
}

.tag-crypto  { color: var(--accent-blue);   background: #1F6FEB11; border-color: #1F6FEB44; }
.tag-mpc     { color: var(--accent-violet); background: #A371F711; border-color: #A371F744; }
.tag-software{ color: var(--accent-green);  background: #2EA04311; border-color: #2EA04344; }
.tag-quantum { color: var(--accent-amber);  background: #BB800011; border-color: #BB800044; }

.tags-row { display: flex; flex-wrap: wrap; gap: 8px; margin: 1rem 0; }

/* === Dividers === */
hr {
  border: none;
  border-top: 0.5px solid var(--border);
  margin: 2rem 0;
}

/* === Hero === */
.hero-section {
  padding: 3rem 0 2rem;
  background: none;
  border-radius: 0;
  margin: 0;
  text-align: left;
}

.hero-title {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--text-primary);
  background: none;
  -webkit-background-clip: unset;
  -webkit-text-fill-color: unset;
  background-clip: unset;
  margin: 0 0 0.4rem;
  line-height: 1.2;
}

.hero-subtitle {
  color: var(--text-muted);
  font-size: 1rem;
  font-weight: 400;
  margin: 0 0 1.25rem;
  letter-spacing: 0;
}

.hero-description {
  color: var(--text-muted);
  font-size: 0.925rem;
  max-width: 600px;
  margin: 1.25rem 0 1.5rem;
  line-height: 1.75;
}
.hero-description strong { color: var(--text-primary); font-weight: 600; }

/* === CTA Buttons === */
.cta-buttons { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 1.5rem; }

.cta-button {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 16px;
  background: transparent;
  color: var(--text-muted) !important;
  border: 0.5px solid var(--border);
  border-radius: 4px;
  font-size: 0.875rem;
  font-weight: 400;
  transition: border-color 0.15s, color 0.15s;
}
.cta-button:hover {
  color: var(--text-primary) !important;
  border-color: var(--text-muted);
  text-decoration: none;
}

/* === CV Section === */
.cv-section {
  background: none;
  border: none;
  border-radius: 0;
  padding: 0;
  margin: 2rem 0;
  box-shadow: none;
}

.section-title {
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin: 0 0 1rem;
  text-align: left;
}

.cv-list { list-style: none; padding: 0; }
.cv-list li {
  padding: 8px 0;
  border-bottom: 0.5px solid var(--border);
  color: var(--text-primary);
  font-size: 0.9rem;
}
.cv-list li:last-child { border-bottom: none; }
.cv-list strong { color: var(--text-primary); font-weight: 600; }
.cv-list a { color: var(--accent-blue); }

/* === Content Sections (About) === */
.content-section {
  background: none;
  border: none;
  border-radius: 0;
  padding: 0;
  margin: 2rem 0;
  box-shadow: none;
}

/* === Filter === */
.filter-section { margin: 1.5rem 0 1rem; }
.filter-section h3 { display: none; }
.filter-buttons { display: flex; gap: 8px; flex-wrap: wrap; }

.filter-btn {
  padding: 4px 14px;
  background: transparent;
  border: 0.5px solid var(--border);
  border-radius: 4px;
  cursor: pointer;
  color: var(--text-muted);
  font-size: 0.8rem;
  font-family: var(--font-sans);
  transition: color 0.15s, border-color 0.15s;
}
.filter-btn:hover { color: var(--text-primary); border-color: var(--text-muted); }
.filter-btn.active { color: var(--accent-blue); border-color: var(--accent-blue); }

/* === Publications === */
.publications-container,
.projects-container,
.about-container,
.container { max-width: var(--max-width); margin: 0 auto; }

.publications-header,
.projects-header { margin: 0 0 1.5rem; }

.publications-title,
.projects-title { font-size: 1.75rem; font-weight: 700; margin: 0 0 0.4rem; }

.publications-subtitle,
.projects-subtitle { color: var(--text-muted); margin: 0; font-size: 0.9rem; }

.publications-list { margin: 0; }

.publication-item {
  background: var(--bg-surface);
  border: 0.5px solid var(--border);
  border-radius: 6px;
  padding: 20px 22px;
  margin: 10px 0;
  transition: background 0.15s;
  overflow-wrap: break-word;
}
.publication-item:hover { background: var(--bg-elevated); }
.publication-item.hidden { display: none; }

.publication-type {
  display: inline-block;
  font-size: 10px;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  background: none;
  padding: 0;
  border-radius: 0;
  margin-bottom: 8px;
}
.publication-type.journal    { color: var(--accent-green); }
.publication-type.conference { color: var(--accent-blue); }
.publication-type.preprint   { color: var(--accent-amber); }
.publication-type.thesis     { color: var(--text-muted); }

.publication-title {
  font-size: 0.975rem;
  font-weight: 600;
  color: var(--accent-blue);
  margin: 0 0 6px;
  line-height: 1.45;
}

.publication-authors { color: var(--text-muted); margin: 0 0 3px; font-size: 0.85rem; font-style: normal; }
.publication-venue   { color: var(--text-muted); font-size: 0.85rem; margin: 0 0 3px; }
.publication-year    { color: var(--text-muted); font-size: 0.85rem; margin: 0 0 10px; }

.publication-abstract {
  margin: 10px 0;
}
.publication-abstract summary {
  color: var(--text-muted);
  font-size: 0.8rem;
  font-weight: 500;
  cursor: pointer;
  user-select: none;
  list-style: none;
  display: flex;
  align-items: center;
  gap: 5px;
}
.publication-abstract summary::before {
  content: '▸';
  font-size: 0.7rem;
  transition: transform 0.15s;
}
.publication-abstract[open] summary::before {
  transform: rotate(90deg);
}
.publication-abstract summary:hover { color: var(--text-primary); }
.publication-abstract span {
  color: var(--text-muted);
  font-size: 0.85rem;
  line-height: 1.65;
  margin-top: 6px;
  display: inline;
}

.publication-links { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 12px; }

.publication-link {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-size: 0.78rem;
  padding: 3px 12px;
  background: transparent;
  border: 0.5px solid var(--border);
  border-radius: 4px;
  color: var(--accent-blue);
  transition: background 0.15s;
}
.publication-link:hover { background: var(--bg-elevated); text-decoration: none; }

/* === Projects === */
.project-card {
  background: var(--bg-surface);
  border: 0.5px solid var(--border);
  border-radius: 6px;
  padding: 20px 22px;
  margin: 10px 0;
  transition: background 0.15s;
  box-shadow: none;
}
.project-card:hover { background: var(--bg-elevated); transform: none; box-shadow: none; }

.project-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 10px;
  flex-wrap: wrap;
  gap: 8px;
}

.project-title {
  font-size: 0.975rem;
  font-weight: 600;
  color: var(--accent-green);
  margin: 0;
  flex: 1;
}

.project-description {
  color: var(--text-muted);
  font-size: 0.875rem;
  line-height: 1.65;
  margin-bottom: 14px;
}

.project-links { display: flex; gap: 8px; flex-wrap: wrap; }

.project-tech {
  font-size: 10px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--text-muted);
  background: none;
  padding: 0;
  border-radius: 0;
  align-self: flex-start;
  padding-top: 2px;
}
.project-tech.python { color: var(--accent-green); background: none; }
.project-tech.rust   { color: var(--accent-green); background: none; }

.project-link {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-size: 0.78rem;
  padding: 3px 12px;
  background: transparent;
  border: 0.5px solid var(--border);
  border-radius: 4px;
  color: var(--accent-green);
  transition: background 0.15s;
}
.project-link:hover { background: var(--bg-elevated); text-decoration: none; }

.coming-soon {
  text-align: left;
  padding: 20px 22px;
  background: var(--bg-surface);
  border: 0.5px solid var(--border);
  border-radius: 6px;
  margin: 10px 0;
}
.coming-soon h3 { color: var(--text-muted); margin: 0 0 6px; font-size: 0.875rem; font-weight: 500; }
.coming-soon p  { color: var(--text-muted); margin: 0; font-size: 0.85rem; }

/* === About === */
.intro-section { margin: 0 0 2rem; }
.intro-title { font-size: 2rem; font-weight: 700; margin-bottom: 0.25rem; }
.intro-subtitle { color: var(--text-muted); margin-bottom: 1rem; font-size: 0.95rem; }
.intro-description { color: var(--text-muted); line-height: 1.75; font-size: 0.925rem; }
.intro-description strong { color: var(--text-primary); font-weight: 600; }

.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 24px;
  margin-top: 1rem;
}

.skill-category h4 {
  color: var(--text-muted);
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin: 0 0 8px;
}

.skill-list { list-style: none; padding: 0; margin: 0; }
.skill-list li {
  padding: 5px 0;
  color: var(--text-primary);
  font-size: 0.875rem;
  border-bottom: 0.5px solid var(--border);
}
.skill-list li:last-child { border-bottom: none; }

.highlight-box {
  border: 0.5px solid var(--border);
  border-left: 2px solid var(--accent-blue);
  border-radius: 4px;
  padding: 18px 22px;
  margin: 2rem 0;
  background: var(--bg-surface);
}
.highlight-title {
  font-size: 0.7rem;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin: 0 0 8px;
}
.highlight-text  { color: var(--text-muted); font-size: 0.875rem; line-height: 1.75; margin: 0; }

.contact-section {
  margin: 2rem 0;
  background: none;
  border: none;
  border-radius: 0;
  padding: 0;
  text-align: left;
}
.contact-title { font-size: 1.1rem; font-weight: 600; margin: 0 0 8px; color: var(--text-primary); }
.contact-description { font-size: 0.875rem; margin: 0 0 14px; color: var(--text-muted); line-height: 1.65; }
.contact-links { display: flex; gap: 10px; flex-wrap: wrap; }

.contact-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 16px;
  background: transparent;
  border: 0.5px solid var(--border);
  border-radius: 4px;
  color: var(--accent-blue);
  font-size: 0.875rem;
  font-weight: 400;
  transition: background 0.15s;
}
.contact-link:hover { background: var(--bg-elevated); text-decoration: none; color: var(--accent-blue); }


/* === Responsive === */
@media (max-width: 600px) {
  .hero-title { font-size: 1.9rem; }
  .publications-title, .projects-title, .intro-title { font-size: 1.5rem; }
  .skills-grid { grid-template-columns: 1fr 1fr; }
  .project-header { flex-direction: column; align-items: flex-start; }
  .cta-buttons { gap: 8px; }
  .nav-links { gap: 1.25rem; }
}

@media (max-width: 400px) {
  .skills-grid { grid-template-columns: 1fr; }
  .nav-inner { flex-direction: column; align-items: flex-start; }
}