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

:root {
  /* ── Palette: Steel Robot ─────────────────────────────── */
  --ink:      #0d1117;
  --paper:    #f0f3f8;
  --warm:     #e2e8f1;
  --blue:     #1d6ef5;
  --blue-l:   #dbeafe;
  --cyan:     #0891b2;
  --cyan-l:   #cffafe;
  --red:      #e53e3e;
  --muted:    #5a6a7e;
  --border:   #c8d4e3;

  /* ── Typography ───────────────────────────────────────── */
  --mono:     'Roboto Mono', monospace;
  --sans:     'Noto Sans', sans-serif;
  --display:  'Roboto', sans-serif;

  /* ── Shadows & easing ─────────────────────────────────── */
  --shadow-sm: 0 2px 8px rgba(13,17,23,0.08);
  --shadow-md: 0 8px 24px rgba(13,17,23,0.10);
  --shadow-lg: 0 20px 48px rgba(13,17,23,0.14);
  --ease:      cubic-bezier(0.4, 0, 0.2, 1);
}

html { scroll-behavior: smooth; }

body {
  font-family: var(--sans);
  font-weight: 400;
  background: var(--paper);
  color: var(--ink);
  font-size: 16px;
  line-height: 1.7;
  overflow-x: hidden;
}

/* Subtle noise texture */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)' opacity='0.035'/%3E%3C/svg%3E");
  pointer-events: none;
  z-index: 9999;
  opacity: 0.4;
}

/* ── MATERIAL SYMBOLS ────────────────────────────────────── */
.material-symbols-outlined {
  font-variation-settings: 'FILL' 0, 'wght' 200, 'GRAD' 0, 'opsz' 24;
  font-size: inherit;
  line-height: 1;
  vertical-align: middle;
  user-select: none;
  display: inline-flex;
  align-items: center;
}

/* ── SCROLL PROGRESS ─────────────────────────────────────── */
.scroll-progress {
  position: fixed;
  top: 0; left: 0;
  height: 2px;
  width: 0%;
  background: linear-gradient(90deg, var(--blue), #67b3fb);
  z-index: 10000;
  transition: width 0.08s linear;
}

/* ── NAV ─────────────────────────────────────────────────── */
nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 200;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.25rem 2.5rem;
  background: rgba(240,243,248,0.6);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid transparent;
  transition: padding 0.3s var(--ease), border-color 0.3s var(--ease),
              background 0.3s var(--ease), box-shadow 0.3s var(--ease);
}

nav.scrolled {
  padding: 0.75rem 2.5rem;
  background: rgba(240,243,248,0.94);
  border-bottom-color: var(--border);
  box-shadow: var(--shadow-sm);
}

.nav-logo {
  font-family: var(--mono);
  font-weight: 500;
  font-size: 1rem;
  color: var(--ink);
  text-decoration: none;
  transition: opacity 0.2s;
}

.nav-logo:hover { opacity: 0.65; }
.nav-logo span  { color: var(--blue); }

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

.nav-links a {
  font-family: var(--mono);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.09em;
  color: var(--muted);
  text-decoration: none;
  position: relative;
  transition: color 0.2s;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -3px; left: 0; right: 0;
  height: 1px;
  background: var(--blue);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.25s var(--ease);
}

.nav-links a:hover         { color: var(--ink); }
.nav-links a:hover::after,
.nav-links a.active::after { transform: scaleX(1); }
.nav-links a.active        { color: var(--ink); }

.nav-right {
  display: flex;
  align-items: center;
  gap: 1rem;
}

/* ── LANGUAGE TOGGLE ──────────────────────────────────────── */
.lang-toggle {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  color: var(--muted);
  background: var(--warm);
  border: 1px solid var(--border);
  border-radius: 3px;
  padding: 0.4rem 0.7rem;
  cursor: pointer;
  transition: border-color 0.2s var(--ease), color 0.2s var(--ease),
              background 0.2s var(--ease), transform 0.15s var(--ease);
}

.lang-toggle:hover {
  border-color: var(--blue);
  color: var(--ink);
  background: var(--blue-l);
  transform: translateY(-1px);
}

.lang-flag { font-size: 1rem; line-height: 1; }
.lang-code { font-weight: 700; }

.nav-cta {
  font-family: var(--mono);
  font-size: 0.72rem;
  background: var(--ink);
  color: var(--paper);
  padding: 0.5rem 1.1rem;
  border-radius: 3px;
  text-decoration: none;
  letter-spacing: 0.06em;
  transition: background 0.25s var(--ease), transform 0.25s var(--ease),
              box-shadow 0.25s var(--ease);
}

.nav-cta:hover {
  background: var(--blue);
  transform: translateY(-1px);
  box-shadow: 0 4px 14px rgba(29,110,245,0.35);
}

.nav-cta .material-symbols-outlined,
.btn-primary .material-symbols-outlined,
.btn-secondary .material-symbols-outlined {
  font-size: 1rem;
}

.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.hamburger span {
  display: block;
  width: 22px; height: 2px;
  background: var(--ink);
  border-radius: 1px;
  transition: transform 0.3s var(--ease), opacity 0.3s var(--ease);
}

.hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; transform: scaleX(0); }
.hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ── HERO ────────────────────────────────────────────────── */
.hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding: 7rem 2.5rem 4rem;
  max-width: 1200px;
  margin: 0 auto;
  position: relative;
}

#brainCanvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: -1;
}

.hero-eyebrow {
  font-family: var(--mono);
  font-size: 1.2rem;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--blue);
  margin-bottom: 1.2rem;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.6rem;
  opacity: 0;
  animation: fadeUp 0.6s var(--ease) 0.1s forwards;
}

.hero-eyebrow::before {
  content: '';
  display: inline-block;
  width: 2rem; height: 1px;
  background: var(--blue);
}

.hero-eyebrow::after {
  content: '';
  display: inline-block;
  width: 2rem; height: 1px;
  background: var(--blue);
}

h1 {
  font-family: var(--display);
  font-size: clamp(3rem, 6vw, 5.5rem);
  font-weight: 100;
  line-height: 1;
  letter-spacing: 0.01em;
  margin-bottom: 1.5rem;
  opacity: 0;
  animation: fadeUp 0.6s var(--ease) 0.2s forwards;
}

h1 .accent {
  background: linear-gradient(135deg, var(--blue) 20%, #67b3fb);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

h1 .line2 {
  display: block;
  -webkit-text-fill-color: var(--muted);
  font-size: 0.45em;
  font-weight: 300;
  letter-spacing: 0.02em;
  margin-top: 0.5rem;
}

.hero-desc {
  font-size: 1.05rem;
  font-weight: 300;
  color: var(--muted);
  max-width: 52ch;
  margin: 0 auto 2.5rem;
  line-height: 1.8;
  opacity: 0;
  animation: fadeUp 0.6s var(--ease) 0.3s forwards;
}

.hero-actions {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  opacity: 0;
  animation: fadeUp 0.6s var(--ease) 0.4s forwards;
}

/* ── BUTTONS ─────────────────────────────────────────────── */
.btn-primary {
  font-family: var(--mono);
  font-size: 0.8rem;
  background: var(--ink);
  color: var(--paper);
  padding: 0.85rem 1.8rem;
  border-radius: 3px;
  text-decoration: none;
  letter-spacing: 0.05em;
  transition: background 0.25s var(--ease), transform 0.25s var(--ease),
              box-shadow 0.25s var(--ease);
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}

.btn-primary:hover {
  background: var(--blue);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(29,110,245,0.32);
}

.btn-secondary {
  font-family: var(--mono);
  font-size: 0.8rem;
  color: var(--ink);
  padding: 0.85rem 1.8rem;
  border: 1px solid var(--border);
  border-radius: 3px;
  text-decoration: none;
  letter-spacing: 0.05em;
  transition: border-color 0.2s, transform 0.25s var(--ease),
              box-shadow 0.25s var(--ease);
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}

.btn-secondary:hover {
  border-color: var(--ink);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

/* ── SECTIONS ────────────────────────────────────────────── */
section {
  max-width: 1200px;
  margin: 0 auto;
  padding: 5rem 2.5rem;
}

.section-label {
  font-family: var(--mono);
  font-size: 1.2rem;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--blue);
  margin-bottom: 0.8rem;
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.section-label::before {
  content: '';
  display: inline-block;
  width: 1.5rem; height: 1px;
  background: var(--blue);
}

.section-label::after {
  content: '';
  display: inline-block;
  width: 1.5rem; height: 1px;
  background: var(--blue);
}

h2 {
  font-family: var(--display);
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 100;
  letter-spacing: 0.01em;
  line-height: 1.15;
  margin-bottom: 1.5rem;
}

/* ── REVEAL ANIMATIONS ───────────────────────────────────── */
.reveal {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.65s var(--ease) var(--delay, 0s),
              transform 0.65s var(--ease) var(--delay, 0s);
}

.reveal.visible       { opacity: 1; transform: translateY(0); }
.reveal-right         { transform: translateX(22px); }
.reveal-right.visible { transform: translateX(0); }

/* ── TRACK CARDS (Project cards) ─────────────────────────── */
.tracks {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
  margin-top: 3rem;
}

.track-card {
  background: var(--warm);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 2rem;
  position: relative;
  overflow: hidden;
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease),
              border-color 0.3s var(--ease);
}

.track-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
  border-color: rgba(29,110,245,0.35);
}

.track-icon {
  font-size: 2.2rem;
  margin-bottom: 1rem;
  color: var(--blue);
  display: block;
}

.track-level {
  font-family: var(--mono);
  font-size: 0.65rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--blue);
  margin-bottom: 0.4rem;
}

.track-card h3 {
  font-family: var(--display);
  font-size: 1.25rem;
  font-weight: 300;
  letter-spacing: 0.01em;
  margin-bottom: 0.6rem;
}

.track-card p { font-size: 0.9rem; color: var(--muted); line-height: 1.6; }

/* Project card links */
.project-links {
  display: flex;
  gap: 1rem;
  margin-top: 1.2rem;
  flex-wrap: wrap;
}

.project-links a {
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.05em;
  color: var(--blue);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  transition: color 0.2s var(--ease);
}

.project-links a:hover {
  color: var(--ink);
}

.project-links a .material-symbols-outlined {
  font-size: 0.9rem;
}

/* ── ABOUT SECTION ───────────────────────────────────────── */
.about-text {
  font-size: 1.05rem;
  font-weight: 300;
  color: var(--muted);
  max-width: 60ch;
  line-height: 1.8;
  margin-bottom: 2rem;
}

.social-links {
  display: flex;
  gap: 1rem;
  align-items: center;
}

.social-links a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px; height: 44px;
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--muted);
  text-decoration: none;
  transition: border-color 0.2s var(--ease), color 0.2s var(--ease),
              transform 0.2s var(--ease), background 0.2s var(--ease);
}

.social-links a:hover {
  border-color: var(--blue);
  color: var(--blue);
  transform: translateY(-2px);
  background: var(--blue-l);
}

.social-links a .material-symbols-outlined {
  font-size: 1.3rem;
}

/* ── DIVIDER ─────────────────────────────────────────────── */
.divider {
  width: 100%;
  height: 1px;
  background: var(--border);
  max-width: 1200px;
  margin: 0 auto;
}

/* ── FOOTER ──────────────────────────────────────────────── */
footer {
  border-top: 1px solid var(--border);
  padding: 2rem 2.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 1200px;
  margin: 0 auto;
}

footer .logo      { font-family: var(--mono); font-weight: 700; font-size: 0.9rem; color: var(--ink); text-decoration: none; }
footer .logo span { color: var(--blue); }
footer p          { font-family: var(--mono); font-size: 0.7rem; color: var(--muted); letter-spacing: 0.04em; }
footer a          { color: var(--muted); text-decoration: none; transition: color 0.2s; }
footer a:hover    { color: var(--ink); }

/* ── PAGE CONTENT (Markdown router overlay) ──────────────── */
#page-content {
  max-width: 1200px;
  margin: 0 auto;
  padding: 7rem 2.5rem 4rem;
  min-height: 60vh;
}

.page-back {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-family: var(--mono);
  font-size: 0.8rem;
  letter-spacing: 0.05em;
  color: var(--blue);
  text-decoration: none;
  margin-bottom: 2.5rem;
  padding: 0.5rem 1rem;
  border: 1px solid var(--border);
  border-radius: 3px;
  transition: border-color 0.2s var(--ease), background 0.2s var(--ease),
              transform 0.2s var(--ease);
}

.page-back:hover {
  border-color: var(--blue);
  background: var(--blue-l);
  transform: translateX(-3px);
}

.page-back .material-symbols-outlined {
  font-size: 1rem;
}

/* Markdown rendered content */
.page-body {
  max-width: 72ch;
}

.page-body h1 {
  font-family: var(--display);
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 100;
  letter-spacing: 0.01em;
  line-height: 1.15;
  margin-bottom: 1.5rem;
  opacity: 1;
  animation: none;
}

.page-body h2 {
  font-family: var(--display);
  font-size: 1.6rem;
  font-weight: 300;
  margin-top: 2.5rem;
  margin-bottom: 1rem;
  color: var(--ink);
}

.page-body h3 {
  font-family: var(--sans);
  font-size: 1.15rem;
  font-weight: 500;
  margin-top: 2rem;
  margin-bottom: 0.8rem;
  color: var(--ink);
}

.page-body p {
  font-size: 1.05rem;
  font-weight: 300;
  color: var(--muted);
  line-height: 1.8;
  margin-bottom: 1.2rem;
}

.page-body strong {
  color: var(--ink);
  font-weight: 500;
}

.page-body em {
  font-style: italic;
}

.page-body a {
  color: var(--blue);
  text-decoration: none;
  border-bottom: 1px solid rgba(29,110,245,0.3);
  transition: border-color 0.2s;
}

.page-body a:hover {
  border-bottom-color: var(--blue);
}

.page-body ul,
.page-body ol {
  margin: 1rem 0 1.5rem 1.5rem;
  color: var(--muted);
  font-size: 1rem;
  line-height: 1.8;
}

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

.page-body code {
  font-family: var(--mono);
  font-size: 0.88em;
  background: var(--warm);
  padding: 0.15em 0.4em;
  border-radius: 3px;
  color: var(--ink);
}

.page-body blockquote {
  border-left: 3px solid var(--blue);
  padding: 0.8rem 1.2rem;
  margin: 1.5rem 0;
  background: var(--blue-l);
  border-radius: 0 6px 6px 0;
  color: var(--muted);
}

.page-body blockquote p {
  margin-bottom: 0;
}

/* ── KEYFRAMES ───────────────────────────────────────────── */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(20px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}

/* ── RESPONSIVE ──────────────────────────────────────────── */
@media (max-width: 900px) {
  nav          { padding: 1rem 1.5rem; }
  nav.scrolled { padding: 0.7rem 1.5rem; }

  .nav-links { display: none; }
  .hamburger { display: flex; }
  .nav-cta   { display: none; }

  .nav-links.open {
    display: flex;
    flex-direction: column;
    position: fixed;
    inset: 0;
    background: rgba(240,243,248,0.97);
    backdrop-filter: blur(24px);
    justify-content: center;
    align-items: center;
    gap: 2.5rem;
    z-index: 150;
  }

  .nav-links.open a { font-size: 1.1rem; letter-spacing: 0.06em; }

  .hero { padding-top: 6rem; }
  .tracks { grid-template-columns: 1fr; }
  .lang-toggle { padding: 0.35rem 0.55rem; }
}

@media (max-width: 600px) {
  section         { padding: 3rem 1.25rem; }
  #page-content   { padding: 5rem 1.25rem 3rem; }
  h1              { font-size: 2.8rem; }
  nav             { padding: 0.9rem 1.25rem; }
  footer          { flex-direction: column; gap: 0.5rem; text-align: center; }
}