/* ===========================
   TomMetrics — Dark + Pop
   =========================== */

:root {
  --bg-primary: #0a0e17;
  --bg-secondary: #111827;
  --bg-card: #151c2c;
  --bg-card-hover: #1a2332;
  --text-primary: #f0f4f8;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --accent: #38bdf8;
  --accent-alt: #818cf8;
  --accent-warm: #f472b6;
  --gradient-start: #38bdf8;
  --gradient-end: #818cf8;
  --border: rgba(148, 163, 184, 0.1);
  --border-hover: rgba(56, 189, 248, 0.3);
  --glow: rgba(56, 189, 248, 0.15);
  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --max-width: 960px;
  --radius: 12px;
  --radius-sm: 8px;
}

/* Reset */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

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

/* ===========================
   Navigation
   =========================== */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(10, 14, 23, 0.8);
  backdrop-filter: blur(16px) saturate(180%);
  -webkit-backdrop-filter: blur(16px) saturate(180%);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.nav-logo {
  font-size: 1.25rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  text-decoration: none;
  letter-spacing: -0.02em;
}

.nav-links {
  list-style: none;
  display: flex;
  gap: 2rem;
  align-items: center;
}

.nav-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
  transition: color 0.2s;
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--gradient-start), var(--gradient-end));
  transition: width 0.3s ease;
  border-radius: 1px;
}

.nav-links a:hover {
  color: var(--text-primary);
}

.nav-links a:hover::after {
  width: 100%;
}

/* Hamburger */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  transition: transform 0.3s, opacity 0.3s;
  border-radius: 2px;
}

.nav-toggle.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.nav-toggle.active span:nth-child(2) {
  opacity: 0;
}

.nav-toggle.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

@media (max-width: 640px) {
  .nav-toggle {
    display: flex;
  }

  .nav-links {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    flex-direction: column;
    background: rgba(10, 14, 23, 0.95);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border);
    padding: 1.5rem;
    gap: 1rem;
  }

  .nav-links.active {
    display: flex;
  }

  .nav-links a::after {
    display: none;
  }
}

/* ===========================
   Hero
   =========================== */
.hero {
  padding: 12rem 0 8rem;
  text-align: center;
  position: relative;
}

/* Ambient glow behind hero */
.hero::before {
  content: '';
  position: absolute;
  top: 20%;
  left: 50%;
  transform: translateX(-50%);
  width: 600px;
  height: 400px;
  background: radial-gradient(ellipse, rgba(56, 189, 248, 0.08) 0%, rgba(129, 140, 248, 0.04) 40%, transparent 70%);
  pointer-events: none;
  z-index: 0;
}

.hero > .container {
  position: relative;
  z-index: 1;
}

.hero-title {
  font-size: 4rem;
  font-weight: 800;
  letter-spacing: -0.04em;
  line-height: 1.05;
  margin-bottom: 0.75rem;
}

.hero-subtitle {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: 1.5rem;
  background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-tagline {
  font-size: 1.1rem;
  color: var(--text-secondary);
  max-width: 560px;
  margin: 0 auto 2.5rem;
  line-height: 1.7;
}

.hero-cta {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

/* ===========================
   Buttons
   =========================== */
.btn {
  display: inline-flex;
  align-items: center;
  padding: 0.75rem 1.75rem;
  font-size: 0.9rem;
  font-weight: 600;
  text-decoration: none;
  border-radius: var(--radius-sm);
  transition: all 0.25s ease;
  cursor: pointer;
  border: none;
}

.btn-primary {
  background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
  color: var(--bg-primary);
  box-shadow: 0 4px 16px rgba(56, 189, 248, 0.25);
}

.btn-primary:hover {
  box-shadow: 0 6px 24px rgba(56, 189, 248, 0.35);
  transform: translateY(-1px);
}

.btn-outline {
  border: 1px solid var(--border);
  color: var(--text-primary);
  background: transparent;
}

.btn-outline:hover {
  border-color: var(--accent);
  background: rgba(56, 189, 248, 0.05);
}

/* ===========================
   Sections
   =========================== */
.section {
  padding: 6rem 0;
}

.section-alt {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.section-title {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 2.5rem;
  letter-spacing: -0.02em;
  position: relative;
  display: inline-block;
}

.section-title::after {
  content: '';
  display: block;
  width: 48px;
  height: 3px;
  background: linear-gradient(90deg, var(--gradient-start), var(--gradient-end));
  border-radius: 2px;
  margin-top: 0.75rem;
}

/* ===========================
   About
   =========================== */
.about-content p {
  font-size: 1.05rem;
  color: var(--text-secondary);
  margin-bottom: 1rem;
  max-width: 700px;
}

.about-content p:first-child::first-line {
  color: var(--text-primary);
  font-weight: 500;
}

/* ===========================
   Project Cards
   =========================== */
.project-grid {
  display: grid;
  gap: 1.5rem;
}

.project-card {
  display: block;
  text-decoration: none;
  color: inherit;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

/* Gradient border glow on hover */
.project-card::before {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: var(--radius);
  padding: 1px;
  background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
  -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.project-card:hover::before {
  opacity: 1;
}

.project-card:hover {
  background: var(--bg-card-hover);
  transform: translateY(-4px);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.3), 0 0 40px var(--glow);
}

.project-card-inner {
  padding: 2rem;
  position: relative;
  z-index: 1;
}

.project-card h3 {
  font-size: 1.4rem;
  margin-bottom: 0.75rem;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.project-card-desc {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-bottom: 1.5rem;
  line-height: 1.7;
}

.project-card-link {
  color: var(--accent);
  font-size: 0.9rem;
  font-weight: 600;
  transition: color 0.2s;
}

.project-card:hover .project-card-link {
  color: var(--accent-alt);
}

/* ===========================
   Tech Pills
   =========================== */
.tech-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1.25rem;
}

.pill {
  display: inline-block;
  padding: 0.3rem 0.85rem;
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  background: rgba(56, 189, 248, 0.08);
  color: var(--accent);
  border: 1px solid rgba(56, 189, 248, 0.15);
  border-radius: 100px;
  transition: all 0.2s;
}

.pill:nth-child(even) {
  color: var(--accent-alt);
  background: rgba(129, 140, 248, 0.08);
  border-color: rgba(129, 140, 248, 0.15);
}

/* ===========================
   Skills Grid
   =========================== */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 2rem;
}

.skill-group {
  padding: 1.5rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: border-color 0.3s;
}

.skill-group:hover {
  border-color: var(--border-hover);
}

.skill-group h3 {
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 1rem;
  background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.skill-group ul {
  list-style: none;
}

.skill-group li {
  padding: 0.35rem 0;
  color: var(--text-secondary);
  font-size: 0.92rem;
  position: relative;
  padding-left: 1rem;
}

.skill-group li::before {
  content: '>';
  position: absolute;
  left: 0;
  color: var(--accent);
  font-weight: 600;
  font-size: 0.8rem;
}

/* ===========================
   Contact
   =========================== */
.contact-text {
  color: var(--text-secondary);
  font-size: 1.1rem;
  margin-bottom: 2rem;
  max-width: 500px;
}

.contact-links {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

/* ===========================
   Footer
   =========================== */
.footer {
  padding: 2.5rem 0;
  border-top: 1px solid var(--border);
  text-align: center;
}

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

/* ===========================
   Project Detail Page
   =========================== */
.project-detail {
  padding-top: 7rem;
  padding-bottom: 5rem;
}

.project-header {
  margin-bottom: 3rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--border);
}

.back-link {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.9rem;
  margin-bottom: 2rem;
  transition: color 0.2s;
  font-weight: 500;
}

.back-link:hover {
  color: var(--accent);
}

.project-header h1 {
  font-size: 2.75rem;
  font-weight: 800;
  margin-bottom: 1rem;
  letter-spacing: -0.03em;
  line-height: 1.1;
}

.project-summary {
  font-size: 1.1rem;
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
  max-width: 700px;
  line-height: 1.7;
}

.project-links {
  display: flex;
  gap: 1rem;
  margin-top: 2rem;
  flex-wrap: wrap;
}

/* Project body content */
.project-body h2 {
  font-size: 1.5rem;
  font-weight: 700;
  margin-top: 4rem;
  margin-bottom: 1.25rem;
  padding-bottom: 0.6rem;
  border-bottom: 1px solid var(--border);
  letter-spacing: -0.01em;
}

.project-body h3 {
  font-size: 1.15rem;
  font-weight: 600;
  margin-top: 2.5rem;
  margin-bottom: 0.75rem;
  color: var(--text-primary);
}

.project-body p {
  color: var(--text-secondary);
  margin-bottom: 1rem;
  line-height: 1.8;
}

.project-body ul,
.project-body ol {
  color: var(--text-secondary);
  margin-left: 1.5rem;
  margin-bottom: 1rem;
}

.project-body li {
  margin-bottom: 0.4rem;
}

.project-body a {
  color: var(--accent);
  text-decoration: none;
  font-weight: 500;
}

.project-body a:hover {
  text-decoration: underline;
}

.project-body hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 3.5rem 0;
}

.project-body strong {
  color: var(--text-primary);
  font-weight: 600;
}

/* Tables */
.project-body table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 2rem;
  font-size: 0.95rem;
  background: var(--bg-card);
  border-radius: var(--radius-sm);
  overflow: hidden;
  border: 1px solid var(--border);
}

.project-body th {
  text-align: left;
  padding: 0.85rem 1.25rem;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
  color: var(--text-primary);
  font-weight: 600;
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.project-body td {
  padding: 0.75rem 1.25rem;
  border-bottom: 1px solid var(--border);
  color: var(--text-secondary);
}

.project-body tr:last-child td {
  border-bottom: none;
}

/* Mermaid diagram */
.mermaid-wrapper {
  margin: 2.5rem calc(-1 * (50vw - var(--max-width) / 2 - 1.5rem));
  padding: 1.5rem;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  position: relative;
}

@media (max-width: 1100px) {
  .mermaid-wrapper {
    margin: 2.5rem -1.5rem;
    border-radius: 0;
  }
}

.mermaid-scroll {
  overflow-x: auto;
  overflow-y: hidden;
  padding: 1rem 0;
}

.mermaid svg {
  display: block;
  margin: 0 auto;
  width: 100% !important;
  height: auto !important;
  overflow: visible;
}

/* Prevent subgraph labels from clipping */
.mermaid svg .cluster-label foreignObject {
  overflow: visible;
}

.mermaid svg .cluster-label span.nodeLabel,
.mermaid svg .cluster-label span.nodeLabel p,
.mermaid svg .cluster-label foreignObject div,
.mermaid svg .cluster-label foreignObject span {
  line-height: 1.2 !important;
}

.mermaid-toolbar {
  display: flex;
  justify-content: flex-end;
  gap: 0.5rem;
  margin-bottom: 0.75rem;
}

.mermaid-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.4rem 0.85rem;
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--text-secondary);
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 6px;
  cursor: pointer;
  transition: all 0.2s;
  position: relative;
  z-index: 2;
}

.mermaid-btn:hover {
  color: var(--text-primary);
  border-color: var(--accent);
  background: rgba(56, 189, 248, 0.05);
}

/* Fullscreen mode */
.mermaid-wrapper.fullscreen {
  position: fixed;
  inset: 0;
  z-index: 1000;
  margin: 0;
  border-radius: 0;
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
}

.mermaid-wrapper.fullscreen .mermaid-scroll {
  flex: 1;
  overflow: auto;
}

.mermaid-wrapper.fullscreen .mermaid svg {
  width: auto !important;
  min-width: 100%;
  min-height: calc(100vh - 6rem);
}

/* Interactive highlighting */
.mermaid svg .node {
  cursor: pointer;
  transition: opacity 0.3s;
}

.mermaid svg path.flowchart-link {
  transition: opacity 0.3s, stroke 0.3s, stroke-width 0.3s;
}

.mermaid svg .edgeLabel {
  transition: opacity 0.3s;
}

.mermaid svg.dimmed .node {
  opacity: 0.1;
}

.mermaid svg.dimmed path.flowchart-link {
  opacity: 0.06;
}

.mermaid svg.dimmed .edgeLabel {
  opacity: 0.06;
}

.mermaid svg.dimmed .node.highlighted {
  opacity: 1;
}

.mermaid svg.dimmed .node.highlighted rect,
.mermaid svg.dimmed .node.highlighted polygon {
  stroke: var(--accent) !important;
  stroke-width: 2.5px !important;
}

/* Highlighted edge arrows */
.mermaid svg.dimmed path.flowchart-link.highlighted {
  opacity: 1;
  stroke: var(--accent) !important;
  stroke-width: 3px !important;
}

.diagram-note {
  text-align: center;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-top: -1rem;
  margin-bottom: 2rem;
}

.diagram-note a {
  color: var(--accent);
  text-decoration: none;
}

.diagram-note a:hover {
  text-decoration: underline;
}

/* Code blocks */
.project-body code {
  font-family: 'JetBrains Mono', 'Fira Code', monospace;
  font-size: 0.85em;
  padding: 0.2em 0.5em;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 4px;
  color: var(--accent);
}

/* ===========================
   Charts (ECharts)
   =========================== */
.chart-section {
  margin-top: 4rem;
}

.chart-section > h2 {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 1.25rem;
  padding-bottom: 0.6rem;
  border-bottom: 1px solid var(--border);
  letter-spacing: -0.01em;
}

.chart-grid {
  display: grid;
  gap: 2rem;
  margin-top: 2rem;
}

.chart-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  transition: border-color 0.3s;
  position: relative;
}

.chart-card:hover {
  border-color: var(--border-hover);
}

.chart-card h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 0.4rem;
  color: var(--text-primary);
}

.chart-card .chart-subtitle,
.mermaid-wrapper .chart-subtitle {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 1.25rem;
  line-height: 1.5;
}

.chart-container {
  width: 100%;
  height: 380px;
}

.chart-container.chart-tall {
  height: 540px;
}

.chart-container.chart-short {
  height: 320px;
}

/* Model badge */
.chart-model-badge {
  display: inline-block;
  font-family: 'JetBrains Mono', 'Fira Code', monospace;
  font-size: 0.72rem;
  color: var(--accent-alt);
  border: 1px solid rgba(129, 140, 248, 0.3);
  border-radius: 4px;
  padding: 0.2rem 0.6rem;
  margin-bottom: 1rem;
  line-height: 1.4;
}

/* D3 chart tooltip */
.chart-tooltip {
  position: absolute;
  pointer-events: none;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.6rem 0.8rem;
  font-size: 0.82rem;
  color: var(--text-primary);
  line-height: 1.5;
  z-index: 2000;
  max-width: 300px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.4);
}

/* D3 SVG text inherits site font */
.chart-container svg text {
  font-family: var(--font);
}

/* Expand / fullscreen button */
.chart-fs-btn {
  position: absolute;
  top: 1rem;
  right: 1rem;
  padding: 0.35rem 0.75rem;
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--text-secondary);
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 6px;
  cursor: pointer;
  transition: all 0.2s;
  z-index: 10;
}

.chart-fs-btn:hover {
  color: var(--text-primary);
  border-color: var(--accent);
  background: rgba(56, 189, 248, 0.08);
}

/* Fullscreen mode */
.chart-card.chart-fullscreen,
.mermaid-wrapper.chart-fullscreen {
  position: fixed;
  inset: 0;
  z-index: 1000;
  border-radius: 0;
  padding: 2rem;
  background: var(--bg-primary);
  overflow-y: auto;
}

.chart-card.chart-fullscreen .chart-container,
.chart-card.chart-fullscreen .chart-container.chart-tall,
.chart-card.chart-fullscreen .chart-container.chart-short,
.mermaid-wrapper.chart-fullscreen .chart-container,
.mermaid-wrapper.chart-fullscreen .chart-container.chart-tall {
  height: calc(100vh - 10rem);
}

@media (max-width: 640px) {
  .chart-container {
    height: 300px;
  }
  .chart-container.chart-tall {
    height: 420px;
  }
  .chart-container.chart-short {
    height: 260px;
  }
  .chart-card {
    padding: 1rem;
  }
  .chart-card.chart-fullscreen {
    padding: 1rem;
  }
  .chart-card.chart-fullscreen .chart-container,
  .chart-card.chart-fullscreen .chart-container.chart-tall,
  .chart-card.chart-fullscreen .chart-container.chart-short {
    height: calc(100vh - 8rem);
  }
}

/* ===========================
   Responsive
   =========================== */
@media (max-width: 640px) {
  .hero {
    padding: 8rem 0 5rem;
  }

  .hero-title {
    font-size: 2.75rem;
  }

  .hero-subtitle {
    font-size: 1.2rem;
  }

  .hero-tagline {
    font-size: 1rem;
  }

  .section {
    padding: 4rem 0;
  }

  .section-title {
    font-size: 1.5rem;
  }

  .project-header h1 {
    font-size: 2rem;
  }

  .skills-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
  }

  .skill-group {
    padding: 1.25rem;
  }

  .project-card-inner {
    padding: 1.5rem;
  }
}

@media (max-width: 400px) {
  .skills-grid {
    grid-template-columns: 1fr;
  }
}