/* ==========================================================
   DESIGN TOKENS
   Signature: the "pipeline" motif — this portfolio is built by
   someone who builds data pipelines, so the hero, dividers, and
   card structure all echo input -> process -> output.

   Color: near-black engineering surface, two accent signals:
     amber  = perception / vision work
     teal   = language / reasoning work
   used sparingly, never both at full saturation at once.

   Type: IBM Plex Mono for display/labels (technical, precise),
   Inter for body copy (readable at length).
   ========================================================== */

:root {
  --bg: #0B0D10;
  --bg-elevated: #12151A;
  --bg-card: #15181D;
  --bg-card-hover: #1A1E24;
  --border: #24282F;
  --border-soft: #1C2026;

  --text-primary: #ECEEF1;
  --text-secondary: #9AA3AD;
  --text-tertiary: #656D77;

  --accent: #E0A458;        /* amber — vision / signature */
  --accent-soft: rgba(224, 164, 88, 0.12);
  --accent-2: #4FD1C5;      /* teal — language / reasoning */
  --accent-2-soft: rgba(79, 209, 197, 0.12);

  --cat-cv: #E0A458;
  --cat-nlp: #4FD1C5;
  --cat-agents: #A78BFA;
  --cat-ml: #F0708A;

  --font-display: 'IBM Plex Mono', ui-monospace, monospace;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;

  --max-width: 1120px;
}

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

html { scroll-behavior: smooth; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; }
}

body {
  background: var(--bg);
  color: var(--text-primary);
  font-family: var(--font-body);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

a { color: inherit; text-decoration: none; }
ul { list-style: none; }
img { max-width: 100%; display: block; }

.section-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 32px;
}

/* subtle background grid texture, engineering-blueprint feel */
main {
  background-image:
    linear-gradient(var(--border-soft) 1px, transparent 1px),
    linear-gradient(90deg, var(--border-soft) 1px, transparent 1px);
  background-size: 64px 64px;
  background-position: center top;
  background-attachment: fixed;
  -webkit-mask-image: linear-gradient(to bottom, black, black);
}

/* ==================== NAV ==================== */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(11, 13, 16, 0.85);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border-soft);
}
.nav-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 16px 32px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}
.nav-brand {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 15px;
  letter-spacing: 0.02em;
}
.nav-brand-dot { color: var(--accent); }
.nav-links {
  display: flex;
  gap: 28px;
  margin-left: auto;
  margin-right: 12px;
}
.nav-links a {
  font-size: 13.5px;
  color: var(--text-secondary);
  font-family: var(--font-display);
  transition: color 0.15s ease;
  white-space: nowrap;
}
.nav-links a:hover { color: var(--text-primary); }
.nav-toggle { display: none; }

/* ==================== BUTTONS ==================== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-display);
  font-size: 13.5px;
  font-weight: 500;
  padding: 11px 20px;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  cursor: pointer;
  transition: all 0.15s ease;
  white-space: nowrap;
}
.btn-primary {
  background: var(--accent);
  color: #17140D;
}
.btn-primary:hover { background: #EBB877; transform: translateY(-1px); }
.btn-ghost {
  border-color: var(--border);
  color: var(--text-primary);
}
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); }
.btn-small { padding: 8px 14px; font-size: 12.5px; }

/* ==================== HERO ==================== */
.hero {
  padding: 110px 32px 90px;
  position: relative;
}
.hero-inner {
  max-width: var(--max-width);
  margin: 0 auto;
}
.eyebrow {
  font-family: var(--font-display);
  font-size: 12.5px;
  letter-spacing: 0.12em;
  color: var(--accent-2);
  margin-bottom: 22px;
}
.hero-title {
  font-family: var(--font-display);
  font-size: clamp(34px, 5.4vw, 62px);
  font-weight: 600;
  line-height: 1.12;
  letter-spacing: -0.01em;
  max-width: 780px;
  margin-bottom: 26px;
}
.accent-text { color: var(--accent); }
.accent-text-2 { color: var(--accent-2); }
.hero-sub {
  font-size: 17px;
  color: var(--text-secondary);
  max-width: 560px;
  margin-bottom: 48px;
}

/* Pipeline signature element */
.pipeline {
  display: flex;
  align-items: center;
  max-width: 620px;
  margin-bottom: 48px;
  padding: 22px 26px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
}
.pipeline-node {
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 92px;
  height: 40px;
  padding: 0 16px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--bg-elevated);
}
.pipeline-node-mid {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}
.pipeline-label {
  font-family: var(--font-display);
  font-size: 13px;
  color: var(--text-primary);
  transition: opacity 0.25s ease;
}
.pipeline-track {
  flex: 1;
  height: 1px;
  background: var(--border);
  margin: 0 10px;
  position: relative;
  overflow: hidden;
}
.pipeline-flow {
  position: absolute;
  top: -1.5px;
  left: -30%;
  width: 30%;
  height: 4px;
  border-radius: 2px;
  background: linear-gradient(90deg, transparent, var(--accent), transparent);
  animation: flow 2.6s linear infinite;
}
.pipeline-track:last-of-type .pipeline-flow {
  background: linear-gradient(90deg, transparent, var(--accent-2), transparent);
  animation-delay: 1.3s;
}
@keyframes flow {
  0% { left: -30%; }
  100% { left: 100%; }
}

.hero-cta {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}

/* ==================== ABOUT ==================== */
.about { padding: 20px 32px 90px; }
.about-text {
  font-size: 19px;
  color: var(--text-secondary);
  max-width: 760px;
  line-height: 1.75;
  margin-bottom: 44px;
}
.about-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  overflow: hidden;
}
.about-stat {
  background: var(--bg-card);
  padding: 24px 20px;
}
.about-stat-num {
  font-family: var(--font-display);
  font-size: 28px;
  font-weight: 600;
  color: var(--accent);
  margin-bottom: 4px;
}
.about-stat-label {
  font-size: 13px;
  color: var(--text-tertiary);
}

/* ==================== SECTION HEADERS ==================== */
.section-eyebrow {
  font-family: var(--font-display);
  font-size: 12.5px;
  letter-spacing: 0.1em;
  color: var(--text-tertiary);
  margin-bottom: 12px;
}
.section-title {
  font-family: var(--font-display);
  font-size: clamp(26px, 3.4vw, 36px);
  font-weight: 600;
  margin-bottom: 48px;
}

/* ==================== EXPERIENCE / TIMELINE ==================== */
.experience { padding: 20px 32px 100px; }
.timeline {
  border-left: 1px solid var(--border);
  padding-left: 36px;
  display: flex;
  flex-direction: column;
  gap: 40px;
}
.timeline-item { position: relative; }
.timeline-item::before {
  content: "";
  position: absolute;
  left: -41px;
  top: 6px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--bg);
  border: 2px solid var(--accent-2);
}
.timeline-head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 8px 20px;
  margin-bottom: 10px;
}
.timeline-role {
  font-size: 18px;
  font-weight: 700;
}
.timeline-org {
  font-size: 15px;
  color: var(--accent-2);
  font-weight: 500;
}
.timeline-dates {
  font-family: var(--font-display);
  font-size: 12.5px;
  color: var(--text-tertiary);
  white-space: nowrap;
}
.timeline-points { color: var(--text-secondary); font-size: 15px; }
.timeline-points li {
  position: relative;
  padding-left: 18px;
  margin-bottom: 6px;
}
.timeline-points li::before {
  content: "—";
  position: absolute;
  left: 0;
  color: var(--text-tertiary);
}

/* ==================== PROJECTS ==================== */
.projects { padding: 20px 32px 100px; }
.filters {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin-bottom: 36px;
}
.filter-btn {
  font-family: var(--font-display);
  font-size: 12.5px;
  padding: 9px 16px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: transparent;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.15s ease;
}
.filter-btn:hover { border-color: var(--text-secondary); color: var(--text-primary); }
.filter-btn.active {
  background: var(--text-primary);
  color: var(--bg);
  border-color: var(--text-primary);
}

.projects-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}
.project-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 26px;
  display: flex;
  flex-direction: column;
  transition: border-color 0.2s ease, transform 0.2s ease, background 0.2s ease;
}
.project-card:hover {
  border-color: var(--border);
  background: var(--bg-card-hover);
  transform: translateY(-2px);
}
.project-card-top {
  display: flex;
  align-items: center;
  gap: 9px;
  margin-bottom: 14px;
}
.cat-dot { width: 7px; height: 7px; border-radius: 50%; flex-shrink: 0; }
.cat-label {
  font-family: var(--font-display);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--text-tertiary);
  text-transform: uppercase;
}
.project-title { font-size: 18px; font-weight: 700; margin-bottom: 4px; }
.project-subtitle { font-size: 13.5px; color: var(--text-secondary); margin-bottom: 14px; }
.project-desc { font-size: 14.5px; color: var(--text-secondary); margin-bottom: 16px; flex-grow: 1; }
.project-highlights { margin-bottom: 16px; }
.project-highlights li {
  font-size: 13.5px;
  color: var(--text-secondary);
  position: relative;
  padding-left: 16px;
  margin-bottom: 6px;
}
.project-highlights li::before {
  content: "▸";
  position: absolute;
  left: 0;
  color: var(--accent);
  font-size: 11px;
}
.project-stack {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 18px;
}
.stack-chip {
  font-family: var(--font-display);
  font-size: 11px;
  padding: 4px 9px;
  border-radius: 4px;
  background: var(--bg-elevated);
  color: var(--text-tertiary);
  border: 1px solid var(--border-soft);
}
.project-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 14px;
  border-top: 1px solid var(--border-soft);
}
.project-result {
  font-family: var(--font-display);
  font-size: 12.5px;
  color: var(--accent);
  font-weight: 500;
}
.project-link {
  font-family: var(--font-display);
  font-size: 12.5px;
  color: var(--text-secondary);
  display: inline-flex;
  align-items: center;
  gap: 5px;
  transition: color 0.15s ease;
}
.project-link:hover { color: var(--accent-2); }

/* ==================== SKILLS ==================== */
.skills { padding: 20px 32px 100px; }
.skills-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-bottom: 56px;
}
.skill-group {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 22px;
}
.skill-group-name {
  font-family: var(--font-display);
  font-size: 13px;
  color: var(--accent-2);
  margin-bottom: 14px;
}
.skill-chips { display: flex; flex-wrap: wrap; gap: 7px; }
.skill-chip {
  font-size: 13px;
  padding: 5px 11px;
  border-radius: 6px;
  background: var(--bg-elevated);
  color: var(--text-secondary);
  border: 1px solid var(--border-soft);
}
.certs-label {
  font-family: var(--font-display);
  font-size: 13px;
  color: var(--text-tertiary);
  margin-bottom: 16px;
}
.certs-list { display: flex; flex-direction: column; gap: 10px; }
.certs-list li {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  padding: 14px 18px;
  background: var(--bg-card);
  border: 1px solid var(--border-soft);
  border-radius: var(--radius-sm);
  font-size: 14px;
  color: var(--text-secondary);
}
.cert-meta { font-family: var(--font-display); font-size: 12px; color: var(--text-tertiary); white-space: nowrap; }

/* ==================== CONTACT ==================== */
.contact { padding: 20px 32px 80px; }
.contact-sub { color: var(--text-secondary); font-size: 16px; margin-bottom: 40px; margin-top: -28px; }
.contact-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
}
.contact-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 22px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  transition: border-color 0.15s ease, transform 0.15s ease;
}
.contact-card:hover { border-color: var(--accent); transform: translateY(-2px); }
.contact-card-label {
  font-family: var(--font-display);
  font-size: 11.5px;
  letter-spacing: 0.06em;
  color: var(--text-tertiary);
  text-transform: uppercase;
}
.contact-card-value { font-size: 14.5px; font-weight: 600; word-break: break-word; }

/* ==================== FOOTER ==================== */
.site-footer { border-top: 1px solid var(--border-soft); padding: 26px 32px; }
.site-footer-inner {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 10px;
  font-family: var(--font-display);
  font-size: 12px;
  color: var(--text-tertiary);
}

/* ==================== RESPONSIVE ==================== */
@media (max-width: 860px) {
  .projects-grid { grid-template-columns: 1fr; }
  .skills-grid { grid-template-columns: 1fr 1fr; }
  .about-stats { grid-template-columns: 1fr 1fr; }
  .contact-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 640px) {
  .nav-links { display: none; }
  .hero { padding: 90px 20px 60px; }
  .about, .experience, .projects, .skills, .contact { padding-left: 20px; padding-right: 20px; }
  .section-inner { padding: 0 20px; }
  .pipeline { flex-wrap: wrap; gap: 10px; padding: 18px; }
  .pipeline-track { display: none; }
  .skills-grid { grid-template-columns: 1fr; }
  .about-stats { grid-template-columns: 1fr 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
  .timeline { padding-left: 24px; }
  .timeline-item::before { left: -29px; }
}

/* Focus visibility for accessibility */
a:focus-visible, button:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}