/* ============================================================
   Design System — Tufte-inspired academic aesthetic
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Crimson+Pro:ital,wght@0,400;0,600;0,700;1,400&family=JetBrains+Mono:wght@400;500&display=swap');

:root {
  --font-serif: 'Crimson Pro', 'ET Book', Palatino, 'Palatino Linotype', Georgia, serif;
  --font-mono: 'JetBrains Mono', 'IBM Plex Mono', Consolas, monospace;
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;

  --color-bg: #fffff8;
  --color-bg-alt: #f8f5ee;
  --color-text: #111111;
  --color-text-secondary: #555555;
  --color-text-tertiary: #888888;
  --color-accent: #1a5c6b;
  --color-accent-hover: #0e3d48;
  --color-accent-light: #e4f0f2;
  --color-gbm: #7850a0;
  --color-rule: #c8c2b4;
  --color-rule-light: #e0dcd4;
  --color-highlight: #fdf6e3;

  --content-width: 640px;
  --margin-width: 240px;
  --gap: 2rem;

  --transition: 0.2s ease;
}

/* ---- Dark Mode ---- */

html[data-theme="dark"] {
  --color-bg: #1a1a1a;
  --color-bg-alt: #242424;
  --color-text: #e0e0e0;
  --color-text-secondary: #aaaaaa;
  --color-text-tertiary: #777777;
  --color-accent: #4db8c9;
  --color-accent-hover: #6dd0df;
  --color-accent-light: rgba(77, 184, 201, 0.12);
  --color-gbm: #a07be0;
  --color-rule: #444444;
  --color-rule-light: #333333;
  --color-highlight: #2a2520;
}

html[data-theme="dark"] ::selection {
  background: rgba(77, 184, 201, 0.25);
}

html[data-theme="dark"] .timeline-item::before {
  border-color: var(--color-bg);
}

/* ---- Reset & Base ---- */

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

html {
  font-size: 18px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-serif);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.65;
  padding: 0;
  transition: background-color 0.3s ease, color 0.3s ease;
}

::selection {
  background: var(--color-accent-light);
  color: var(--color-accent);
}

/* ---- Typography ---- */

h1, h2, h3, h4 {
  font-weight: 600;
  line-height: 1.25;
  letter-spacing: -0.01em;
}

h1 {
  font-size: 2.9rem;
  font-weight: 700;
  margin-bottom: 0.3rem;
}

h2 {
  font-size: 1.5rem;
  margin-top: 3rem;
  margin-bottom: 1rem;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid var(--color-rule-light);
}

h3 {
  font-size: 1.15rem;
  margin-top: 1.5rem;
  margin-bottom: 0.5rem;
}

p {
  margin-bottom: 1rem;
}

a {
  color: var(--color-text);
  text-decoration-color: var(--color-rule);
  text-underline-offset: 2px;
  transition: color var(--transition), text-decoration-color var(--transition);
}

a:hover {
  color: var(--color-accent);
  text-decoration-color: var(--color-accent);
}

strong {
  font-weight: 600;
}

code, .mono {
  font-family: var(--font-mono);
  font-size: 0.82rem;
}

hr {
  border: none;
  border-top: 1px solid var(--color-rule-light);
  margin: 2.5rem 0;
}

/* ---- Layout ---- */

.page-wrapper {
  max-width: calc(var(--content-width) + var(--margin-width) * 2 + var(--gap) * 2);
  margin: 0 auto;
  padding: 3rem 2rem 4rem;
}

.content {
  max-width: var(--content-width);
  margin: 0 auto;
}

/* ---- GBM Canvas / Hero ---- */

.gbm-strip {
  position: relative;
  width: 100%;
  height: 240px;
  overflow: hidden;
  margin: 1.2rem 0 3rem;
  border-top: 1px solid var(--color-rule-light);
  border-bottom: 1px solid var(--color-rule-light);
}

#gbm-canvas {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

.gbm-caption {
  position: absolute;
  bottom: 0.6rem;
  right: 0.9rem;
  font-family: var(--font-mono);
  font-size: 0.64rem;
  color: var(--color-text-tertiary);
  letter-spacing: 0.04em;
  pointer-events: none;
  background: var(--color-bg);
  padding: 0.15rem 0.4rem;
  border-radius: 2px;
}

/* ---- About ---- */

.about-section {
  margin-bottom: 0.5rem;
}

.about-section p {
  font-size: 0.95rem;
  color: var(--color-text-secondary);
  line-height: 1.7;
  max-width: 560px;
  margin-bottom: 0;
}

.about-lead {
  font-size: 1.15rem;
  font-weight: 500;
  color: var(--color-text);
  line-height: 1.55;
}

/* ---- Header / Nav ---- */

.site-header {
  margin-bottom: 3rem;
}

.contact-bar {
  display: flex;
  align-items: center;
  gap: 2.5rem;
  margin-top: 0.5rem;
  margin-bottom: 0.8rem;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  letter-spacing: 0.02em;
}

.contact-bar a {
  color: var(--color-text-tertiary);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 0.2s, color 0.2s;
}

.contact-bar a:hover {
  border-bottom-color: var(--color-accent);
}

.contact-sep {
  color: var(--color-text-secondary);
  opacity: 0.4;
  user-select: none;
}

.site-header .subtitle {
  font-size: 1.05rem;
  color: var(--color-text-secondary);
  line-height: 1.5;
  max-width: 560px;
}

nav {
  margin-top: 1.5rem;
  display: flex;
  gap: 2.5rem;
  flex-wrap: wrap;
}

nav a {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  text-decoration: none;
  color: var(--color-text-tertiary);
  padding: 0.25rem 0;
  border-bottom: 1.5px solid transparent;
  transition: all var(--transition);
}

nav a:hover, nav a.active {
  color: var(--color-accent);
  border-bottom-color: var(--color-accent);
}

.theme-toggle {
  position: fixed;
  top: 1rem;
  right: 1.5rem;
  z-index: 100;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-text-secondary);
  background: var(--color-bg);
  border: 1px solid var(--color-rule);
  border-radius: 2px;
  padding: 0.25rem 0.7rem;
  cursor: pointer;
  transition: all var(--transition);
}

.theme-toggle:hover {
  color: var(--color-accent);
  border-color: var(--color-accent);
}

/* ---- Metrics Strip ---- */

.metrics-strip {
  display: flex;
  gap: 0;
  margin: 2rem 0 2.5rem;
  border-top: 2px solid var(--color-text);
  border-bottom: 1px solid var(--color-rule);
  padding: 0;
  overflow-x: auto;
}

.metric {
  flex: 1;
  padding: 0.9rem 1rem;
  min-width: 0;
  border-right: 1px solid var(--color-rule-light);
  text-align: center;
}

.metric:last-child {
  border-right: none;
}

.metric-value {
  font-family: var(--font-mono);
  font-size: 1.35rem;
  font-weight: 500;
  color: var(--color-text);
  letter-spacing: -0.02em;
  display: block;
  line-height: 1.2;
}

.metric-label {
  font-family: var(--font-mono);
  font-size: 0.62rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-text-tertiary);
  display: block;
  margin-top: 0.2rem;
}

/* ---- Project Cards ---- */

.projects-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
}

.project-card {
  padding: 1.8rem 0.8rem;
  margin: 0 -0.8rem;
  border-bottom: 1px solid var(--color-rule-light);
  border-radius: 3px;
  transition: background var(--transition), transform var(--transition), box-shadow var(--transition);
}

.project-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
  background: var(--color-bg-alt);
}

.project-card:first-child {
  border-top: 1px solid var(--color-rule-light);
}

.project-number {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--color-text-tertiary);
  letter-spacing: 0.05em;
  margin-bottom: 0.3rem;
}

.project-card h3 {
  font-size: 1.2rem;
  margin: 0 0 0.4rem;
}

.project-card h3 a {
  text-decoration: none;
}

.project-card h3 a:hover {
  text-decoration: underline;
  text-decoration-color: var(--color-accent);
  text-underline-offset: 3px;
}

.project-origin {
  font-style: italic;
  font-size: 0.88rem;
  color: var(--color-text-secondary);
  margin-bottom: 0.6rem;
}

.project-desc {
  font-size: 0.95rem;
  line-height: 1.6;
  margin-bottom: 0.8rem;
}

.project-result {
  font-family: var(--font-mono);
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--color-text);
  background: var(--color-bg-alt);
  border-left: 3px solid var(--color-accent);
  padding: 0.7rem 0.95rem;
  margin-bottom: 0.9rem;
  display: inline-block;
}

.project-stack {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--color-text-tertiary);
  letter-spacing: 0.04em;
}

/* ---- Timeline ---- */

.timeline {
  position: relative;
  padding-left: 1.5rem;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.4rem;
  bottom: 0.4rem;
  width: 1px;
  background: var(--color-rule);
}

.timeline-item {
  position: relative;
  padding-bottom: 1.3rem;
  padding-left: 1rem;
}

.timeline-item:last-child {
  padding-bottom: 0;
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: -1.75rem;
  top: 0.5rem;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--color-rule);
  border: 2px solid var(--color-bg);
  box-shadow: 0 0 0 1px var(--color-rule);
}

.timeline-item.current::before {
  background: var(--color-accent);
  box-shadow: 0 0 0 1px var(--color-accent);
}

.timeline-date {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--color-text-tertiary);
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.timeline-role {
  font-weight: 600;
  font-size: 0.95rem;
  line-height: 1.4;
}

.timeline-org {
  font-size: 0.88rem;
  color: var(--color-text-secondary);
}

.timeline-detail {
  font-size: 0.82rem;
  color: var(--color-text-tertiary);
  font-family: var(--font-mono);
}

/* ---- Self-Study Table ---- */

.study-table {
  width: 100%;
  border-collapse: collapse;
  margin: 1rem 0;
  font-size: 0.88rem;
}

.study-table thead {
  border-bottom: 2px solid var(--color-text);
}

.study-table th {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-text-secondary);
  text-align: left;
  padding: 0.5rem 0.8rem 0.5rem 0;
  font-weight: 500;
}

.study-table td {
  padding: 0.6rem 0.8rem 0.6rem 0;
  border-bottom: 1px solid var(--color-rule-light);
  vertical-align: top;
}

.study-table tbody tr:last-child td {
  border-bottom: 1px solid var(--color-rule);
}

.study-table .book-title {
  font-style: italic;
}

.study-table .book-coverage {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--color-text-secondary);
}

/* ---- Inline sidenote (subtle left-border) ---- */

.sidenote-inline {
  font-size: 0.78rem;
  color: var(--color-text-secondary);
  line-height: 1.5;
  margin-top: 0.5rem;
  padding-left: 1rem;
  border-left: 2px solid var(--color-rule-light);
}

/* ---- Skills ---- */

.skills-grid {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0.3rem 1.5rem;
  font-size: 0.88rem;
}

.skill-category {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-text-tertiary);
  padding-top: 0.15rem;
}

.skill-items {
  padding: 0.1rem 0 0.5rem;
  border-bottom: 1px solid var(--color-rule-light);
}

.skills-grid .skill-items:last-child {
  border-bottom: none;
}

.skill-exposure {
  font-style: italic;
  color: var(--color-text-secondary);
}

.skills-legend {
  font-size: 0.82rem;
  color: var(--color-text-secondary);
  margin-top: -0.3rem;
  margin-bottom: 1rem;
}

/* ---- Footer ---- */

.site-footer {
  margin-top: 4rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--color-rule);
  display: flex;
  gap: 1.5rem;
  flex-wrap: wrap;
}

.site-footer a {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--color-text-secondary);
  text-decoration: none;
  letter-spacing: 0.03em;
  transition: color var(--transition);
}

.site-footer a:hover {
  color: var(--color-accent);
}

/* ---- Project Detail Pages ---- */

.project-header {
  margin-bottom: 2rem;
}

.project-header h1 {
  font-size: 2rem;
  margin-bottom: 0.4rem;
}

.project-meta {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--color-text-tertiary);
  display: flex;
  gap: 1.5rem;
  flex-wrap: wrap;
}

.back-link {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  margin-bottom: 2rem;
  display: block;
}

.abstract {
  font-size: 1.05rem;
  line-height: 1.7;
  padding: 1.2rem 0;
  border-top: 1px solid var(--color-rule-light);
  border-bottom: 1px solid var(--color-rule-light);
  margin-bottom: 2rem;
}

/* Architecture diagram */

.architecture {
  background: var(--color-bg-alt);
  border: 1px solid var(--color-rule-light);
  padding: 1.5rem;
  margin: 1.5rem 0;
  overflow-x: auto;
}

.arch-flow {
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  align-items: center;
}

.arch-layer {
  width: 100%;
  max-width: 520px;
  border: 1px solid var(--color-rule);
  background: var(--color-bg);
  padding: 0.8rem 1rem;
  position: relative;
}

.arch-layer-label {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-accent);
  font-weight: 500;
  margin-bottom: 0.3rem;
}

.arch-layer-content {
  font-size: 0.82rem;
  color: var(--color-text-secondary);
}

.arch-arrow {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--color-rule);
  line-height: 1;
}

/* Results table */

.results-table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  font-size: 0.85rem;
}

.results-table thead {
  border-top: 2px solid var(--color-text);
  border-bottom: 1px solid var(--color-text);
}

.results-table th {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-text-secondary);
  text-align: left;
  padding: 0.6rem 0.6rem;
  font-weight: 500;
}

.results-table th.num {
  text-align: right;
}

.results-table td {
  padding: 0.5rem 0.6rem;
  border-bottom: 1px solid var(--color-rule-light);
  vertical-align: top;
}

.results-table td.num {
  text-align: right;
  font-family: var(--font-mono);
  font-size: 0.82rem;
}

.results-table tbody tr:last-child td {
  border-bottom: 2px solid var(--color-text);
}

.results-table .highlight {
  font-weight: 600;
  color: var(--color-accent);
}

/* Key decisions section */

.decision-block {
  margin: 1.5rem 0;
  padding: 0;
}

.decision-block summary {
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  padding: 0.4rem 0;
  list-style: none;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.decision-block summary::before {
  content: '+';
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--color-accent);
  width: 1.2rem;
  flex-shrink: 0;
  transition: transform var(--transition);
}

.decision-block[open] summary::before {
  content: '\2212';
}

.decision-block .decision-content {
  padding: 0.5rem 0 0.5rem 1.7rem;
  font-size: 0.92rem;
}

/* Tech stack inline list */

.stack-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  list-style: none;
  margin: 1rem 0;
}

.stack-list li {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  padding: 0.25rem 0.6rem;
  border: 1px solid var(--color-rule);
  border-radius: 2px;
  color: var(--color-text-secondary);
  letter-spacing: 0.02em;
}

/* ---- Callout block ---- */

.callout {
  background: var(--color-bg-alt);
  border-left: 3px solid var(--color-accent);
  padding: 1rem 1.2rem;
  margin: 1.5rem 0;
  font-size: 0.92rem;
}

.callout p:last-child {
  margin-bottom: 0;
}

/* ---- Responsive ---- */

@media (max-width: 768px) {
  html {
    font-size: 16px;
  }

  .page-wrapper {
    padding: 2rem 1.2rem 3rem;
  }

  h1 {
    font-size: 1.9rem;
  }

  h2 {
    font-size: 1.3rem;
  }

  .metrics-strip {
    flex-wrap: wrap;
  }

  .metric {
    flex: 1 1 30%;
    min-width: 80px;
    padding: 0.7rem 0.6rem;
  }

  .metric-value {
    font-size: 1.15rem;
  }

  .skills-grid {
    grid-template-columns: 1fr;
    gap: 0;
  }

  .skill-category {
    margin-top: 0.6rem;
  }

  nav {
    gap: 1rem;
  }

  .site-footer {
    flex-direction: column;
    gap: 0.8rem;
  }

  .study-table {
    font-size: 0.82rem;
  }
}

@media (max-width: 480px) {
  .metric {
    flex: 1 1 45%;
  }
}