/* ---------- tokens ----------
   Palette: deep teal ground (#224248 / #325e6a), cyan-teal secondary
   (#44a1a4), amber accent (#ff9a00) — per user-supplied palette
   (colorhunt.co/palette/224248325e6a44a1a4ff9a00). Dark is the default
   "world"; light is the same identity in daylight. */
:root {
  --bg: #172e32;
  --bg-alt: #1b363b;
  --surface: #224248;
  --surface-2: #294e55;
  --border: #325e6a;
  --text: #eef7f6;
  --text-dim: #a9c8c9;
  --text-faint: #6f9598;
  --accent: #ff9a00;
  --accent-soft: #ffb84d;
  --accent-2: #44a1a4;
  --nav-bg-1: rgba(23,46,50,0.6);
  --nav-bg-2: rgba(23,46,50,0.92);
  --nav-bg-mobile: rgba(23,46,50,0.98);
  --grid-line: rgba(255,255,255,0.035);
  --ink-on-accent: #16292c;
  --mono: 'IBM Plex Mono', ui-monospace, monospace;
  --sans: 'IBM Plex Sans', -apple-system, BlinkMacSystemFont, sans-serif;
  --display: 'IBM Plex Serif', Georgia, serif;
  --radius: 10px;
  --maxw: 1120px;
}

/* Light theme — same palette in daylight: pale teal ground, white cards,
   darkened amber/teal for AA contrast on white. */
:root[data-theme="light"] {
  --bg: #eaf3f2;
  --bg-alt: #f1f7f6;
  --surface: #ffffff;
  --surface-2: #f4faf9;
  --border: #cfe3e2;
  --text: #16292c;
  --text-dim: #325e6a;
  --text-faint: #6f8f92;
  --accent: #d97f00;
  --accent-soft: #ff9a00;
  --accent-2: #2c7a7d;
  --nav-bg-1: rgba(234,243,242,0.7);
  --nav-bg-2: rgba(234,243,242,0.92);
  --nav-bg-mobile: rgba(241,247,246,0.98);
  --grid-line: rgba(22,41,44,0.05);
  --ink-on-accent: #fffaf2;
}

@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) {
    --bg: #eaf3f2;
    --bg-alt: #f1f7f6;
    --surface: #ffffff;
    --surface-2: #f4faf9;
    --border: #cfe3e2;
    --text: #16292c;
    --text-dim: #325e6a;
    --text-faint: #6f8f92;
    --accent: #d97f00;
    --accent-soft: #ff9a00;
    --accent-2: #2c7a7d;
    --nav-bg-1: rgba(234,243,242,0.7);
    --nav-bg-2: rgba(234,243,242,0.92);
    --nav-bg-mobile: rgba(241,247,246,0.98);
    --grid-line: rgba(22,41,44,0.05);
    --ink-on-accent: #fffaf2;
  }
}

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

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  transition: background-color .25s ease, color .25s ease;
}

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

a { color: inherit; text-decoration: none; }

.container {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 28px;
}

/* ---------- background fx ---------- */
.bg-grid {
  position: fixed; inset: 0; z-index: -2;
  background-image:
    linear-gradient(to right, var(--grid-line) 1px, transparent 1px),
    linear-gradient(to bottom, var(--grid-line) 1px, transparent 1px);
  background-size: 44px 44px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, #000 30%, transparent 100%);
}
.bg-glow {
  position: fixed; z-index: -1; top: -20%; left: 50%;
  width: 900px; height: 900px; transform: translateX(-50%);
  background: radial-gradient(circle, rgba(255,154,0,0.13), rgba(68,161,164,0.08) 40%, transparent 70%);
  filter: blur(10px);
  pointer-events: none;
}

/* ---------- nav ---------- */
#navbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  backdrop-filter: blur(12px);
  background: var(--nav-bg-1);
  border-bottom: 1px solid transparent;
  transition: border-color .3s ease, background .3s ease;
}
#navbar.scrolled { border-bottom-color: var(--border); background: var(--nav-bg-2); }
.nav-inner {
  max-width: var(--maxw); margin: 0 auto; padding: 16px 28px;
  display: flex; align-items: center; justify-content: space-between; gap: 24px;
}
.logo {
  font-family: var(--mono); font-weight: 500; font-size: 1.1rem; color: var(--text);
  letter-spacing: 0.02em;
}
.cursor { color: var(--accent); animation: blink 1.1s step-end infinite; }
@keyframes blink { 50% { opacity: 0; } }

.nav-links { list-style: none; display: flex; gap: 32px; font-family: var(--mono); font-size: 0.88rem; }
.nav-links a { color: var(--text-dim); position: relative; transition: color .2s ease; }
.nav-links a::after {
  content: ""; position: absolute; left: 0; bottom: -6px; width: 0; height: 1px;
  background: var(--accent); transition: width .25s ease;
}
.nav-links a:hover { color: var(--text); }
.nav-links a:hover::after { width: 100%; }

.lang-switch {
  display: flex; align-items: center; border: 1px solid var(--border); border-radius: 7px;
  overflow: hidden; font-family: var(--mono); font-size: 0.76rem;
}
.lang-btn {
  background: none; border: none; color: var(--text-faint); padding: 6px 11px; cursor: pointer;
  transition: background .2s ease, color .2s ease; letter-spacing: 0.02em;
}
.lang-btn + .lang-btn { border-left: 1px solid var(--border); }
.lang-btn:hover { color: var(--text); }
.lang-btn.is-active { background: rgba(255,154,0,0.1); color: var(--accent); }

.nav-controls { display: flex; align-items: center; gap: 10px; }

.theme-toggle {
  display: flex; align-items: center; justify-content: center;
  width: 30px; height: 30px; border: 1px solid var(--border); border-radius: 7px;
  background: none; color: var(--text-faint); cursor: pointer;
  transition: color .2s ease, border-color .2s ease;
}
.theme-toggle:hover { color: var(--accent); border-color: var(--accent); }
.theme-toggle svg { width: 15px; height: 15px; }
.theme-toggle .icon-moon { display: none; }
:root[data-theme="light"] .theme-toggle .icon-sun { display: none; }
:root[data-theme="light"] .theme-toggle .icon-moon { display: block; }
@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) .theme-toggle .icon-sun { display: none; }
  :root:not([data-theme="dark"]) .theme-toggle .icon-moon { display: block; }
}

.nav-toggle { display: none; }

/* ---------- buttons ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 12px 22px; border-radius: 9px; font-weight: 600; font-size: 0.92rem;
  border: 1px solid transparent; transition: transform .18s ease, box-shadow .18s ease, background .18s ease, border-color .18s ease;
  font-family: var(--sans);
}
.btn-primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: var(--ink-on-accent);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 10px 28px -8px rgba(255,154,0,0.45); }
.btn-outline {
  border-color: var(--border); color: var(--text);
}
.btn-outline:hover { border-color: var(--accent); color: var(--accent); transform: translateY(-2px); }
.btn-ghost { border: 1px solid var(--border); color: var(--text-dim); }

/* ---------- hero ---------- */
.hero {
  min-height: 100vh;
  display: flex; align-items: center;
  padding: 140px 0 80px;
  position: relative;
}
.hero-grid {
  display: grid; grid-template-columns: 1.1fr 0.9fr; gap: 56px; align-items: center;
}
.eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  font-family: var(--mono); font-size: 0.82rem; color: var(--accent);
  border: 1px solid rgba(255,154,0,0.25); background: rgba(255,154,0,0.06);
  padding: 6px 14px; border-radius: 999px; margin-bottom: 24px;
}
.dot { width: 7px; height: 7px; border-radius: 50%; background: var(--accent); box-shadow: 0 0 0 3px rgba(255,154,0,0.18); animation: pulse 2s ease-in-out infinite; }
@keyframes pulse { 0%,100% { opacity: 1; } 50% { opacity: 0.4; } }

.hero-text h1 {
  font-family: var(--display); font-size: clamp(2.4rem, 5vw, 3.6rem);
  font-weight: 700; line-height: 1.12; letter-spacing: -0.02em; margin-bottom: 14px;
}
.gradient-text {
  background: linear-gradient(100deg, var(--accent-soft), var(--accent) 65%);
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.hero-role {
  font-family: var(--mono); font-size: clamp(1rem, 2vw, 1.25rem); color: var(--text-dim);
  margin-bottom: 22px; min-height: 1.6em;
}
.type-cursor { color: var(--accent); animation: blink 1s step-end infinite; }
.hero-desc { color: var(--text-dim); font-size: 1.05rem; max-width: 46ch; margin-bottom: 32px; }
.hero-actions { display: flex; gap: 14px; margin-bottom: 36px; flex-wrap: wrap; }
.hero-links { display: flex; gap: 18px; }
.hero-links a { color: var(--text-faint); transition: color .2s ease, transform .2s ease; }
.hero-links a:hover { color: var(--accent); transform: translateY(-2px); }

/* hero model card — presents him as an ML model card (YAML front-matter),
   specific to a data scientist rather than a generic IDE-window prop */
.model-card {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  overflow: hidden; box-shadow: 0 30px 60px -25px rgba(0,0,0,0.7);
}
.model-card-head {
  display: flex; align-items: center; justify-content: space-between;
  padding: 14px 18px; background: var(--surface-2); border-bottom: 1px solid var(--border);
}
.model-card-label { font-family: var(--mono); font-size: 0.78rem; color: var(--text-faint); }
.model-card-badge {
  font-family: var(--mono); font-size: 0.68rem; color: var(--accent);
  border: 1px solid rgba(255,154,0,0.35); background: rgba(255,154,0,0.08);
  padding: 3px 9px; border-radius: 999px; letter-spacing: 0.03em;
}
.model-card-body {
  padding: 24px 22px; font-family: var(--mono); font-size: 0.84rem; line-height: 1.8;
  color: var(--text-dim); overflow-x: auto;
}
.y-rule { color: var(--text-faint); }
.y-key { color: var(--accent-2); }
.y-str { color: var(--text); }
.y-dash { color: var(--accent); }
.y-com { color: var(--text-faint); font-style: italic; }

.scroll-cue {
  position: absolute; bottom: 28px; left: 50%; transform: translateX(-50%);
  width: 26px; height: 42px; border: 2px solid var(--border); border-radius: 20px;
  display: flex; justify-content: center; padding-top: 8px;
}
.scroll-cue span { width: 4px; height: 8px; border-radius: 2px; background: var(--accent); animation: scrolldown 1.6s ease-in-out infinite; }
@keyframes scrolldown { 0% { opacity: 1; transform: translateY(0); } 100% { opacity: 0; transform: translateY(14px); } }

/* ---------- sections ---------- */
.section { padding: 120px 0; position: relative; }
.section-alt { background: linear-gradient(180deg, transparent, rgba(255,255,255,0.015) 8%, rgba(255,255,255,0.015) 92%, transparent); }
.section-tag {
  font-family: var(--mono); font-size: 0.82rem; color: var(--accent); letter-spacing: 0.06em;
  margin-bottom: 14px;
}
.section-title {
  font-family: var(--display); font-size: clamp(1.8rem, 3.4vw, 2.6rem);
  font-weight: 600; letter-spacing: -0.01em; margin-bottom: 20px; max-width: 22ch;
}
.section-sub { color: var(--text-dim); max-width: 60ch; margin-bottom: 48px; margin-top: -8px; }
.section-sub a { color: var(--accent); border-bottom: 1px solid rgba(255,154,0,0.3); }

/* about */
.about-grid { display: grid; grid-template-columns: 1.4fr 1fr; gap: 56px; align-items: start; }
.about-photo {
  width: 104px; height: 104px; border-radius: 50%; object-fit: cover;
  border: 2px solid var(--border); outline: 3px solid rgba(255,154,0,0.15); outline-offset: 3px;
  margin-bottom: 22px; display: block;
}
.about-copy p { color: var(--text-dim); margin-bottom: 18px; font-size: 1.02rem; }
.about-copy strong { color: var(--text); }
.about-stats { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.stat-card {
  background: var(--surface); border: 1px solid var(--border); border-radius: 12px;
  padding: 22px 18px; display: flex; flex-direction: column; gap: 6px;
  transition: border-color .2s ease, transform .2s ease;
}
.stat-card:hover { border-color: var(--accent); transform: translateY(-3px); }
.stat-num { font-family: var(--display); font-size: 1.7rem; font-weight: 700; color: var(--accent); }
.stat-label { font-size: 0.82rem; color: var(--text-faint); font-family: var(--mono); }

/* skills */
.skills-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.skill-card {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 26px; transition: transform .2s ease, border-color .2s ease, box-shadow .2s ease;
}
.skill-card:hover { transform: translateY(-4px); border-color: rgba(255,154,0,0.4); box-shadow: 0 20px 40px -24px rgba(255,154,0,0.25); }
.skill-head { display: flex; align-items: center; gap: 10px; margin-bottom: 16px; }
.skill-icon {
  display: flex; align-items: center; justify-content: center;
  width: 32px; height: 32px; border-radius: 8px; flex-shrink: 0;
  background: rgba(255,154,0,0.1); color: var(--accent);
}
.skill-icon svg { width: 17px; height: 17px; }
.skill-head h3 { font-family: var(--display); font-size: 1.05rem; font-weight: 600; }
.tag-list { display: flex; flex-wrap: wrap; gap: 8px; }
.tag {
  font-family: var(--mono); font-size: 0.76rem; color: var(--text-dim);
  border: 1px solid var(--border); background: rgba(255,255,255,0.02);
  padding: 5px 10px; border-radius: 6px;
}
.tag-list.small .tag { font-size: 0.72rem; padding: 4px 9px; }

/* projects */
.projects-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; margin-bottom: 56px; }
.project-card {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 26px; display: flex; flex-direction: column; gap: 12px;
  transition: transform .2s ease, border-color .2s ease, box-shadow .2s ease;
}
.project-card:hover { transform: translateY(-5px); border-color: rgba(68,161,164,0.4); box-shadow: 0 24px 44px -26px rgba(68,161,164,0.3); }
.project-card.featured { grid-column: span 1; background: linear-gradient(160deg, var(--surface), var(--surface-2)); }
.project-top { display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.project-kind { font-family: var(--mono); font-size: 0.72rem; color: var(--accent-2); text-transform: uppercase; letter-spacing: 0.04em; }
.project-links { display: flex; gap: 12px; font-family: var(--mono); font-size: 0.78rem; }
.project-links a { color: var(--text-dim); border-bottom: 1px solid transparent; transition: color .2s ease, border-color .2s ease; }
.project-links a:hover { color: var(--accent); border-color: var(--accent); }
.project-card h3 { font-family: var(--display); font-size: 1.15rem; font-weight: 600; }
.project-card p { color: var(--text-dim); font-size: 0.92rem; flex: 1; }

.more-projects {
  border-top: 1px solid var(--border); padding-top: 32px;
}
.more-projects h4 { font-family: var(--mono); font-size: 0.85rem; color: var(--text-faint); margin-bottom: 16px; font-weight: 500; }
.more-list { display: flex; flex-wrap: wrap; gap: 14px 28px; }
.more-list a { font-size: 0.92rem; color: var(--text-dim); transition: color .2s ease; }
.more-list a:hover { color: var(--accent); }

/* timeline */
.timeline { position: relative; padding-left: 28px; }
.timeline::before {
  content: ""; position: absolute; left: 5px; top: 6px; bottom: 6px; width: 1px;
  background: linear-gradient(180deg, var(--accent), var(--border) 90%);
}
.timeline-item { position: relative; padding-bottom: 40px; padding-left: 28px; }
.timeline-item:last-child { padding-bottom: 0; }
.timeline-dot {
  position: absolute; left: -28px; top: 5px; width: 11px; height: 11px; border-radius: 50%;
  background: var(--bg); border: 2px solid var(--accent);
}
.timeline-date { font-family: var(--mono); font-size: 0.78rem; color: var(--accent); }
.timeline-content h3 { font-family: var(--display); font-size: 1.1rem; margin: 6px 0 2px; font-weight: 600; }
.timeline-org { color: var(--text-dim); font-size: 0.9rem; margin-bottom: 8px; }
.timeline-content p:last-child { color: var(--text-dim); font-size: 0.92rem; max-width: 60ch; }

/* contact */
.contact-sub { color: var(--text-dim); max-width: 58ch; margin-bottom: 44px; margin-top: -8px; }
.contact-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.contact-card {
  display: flex; flex-direction: column; gap: 8px;
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 26px; transition: transform .2s ease, border-color .2s ease;
}
.contact-card:not(.static):hover { transform: translateY(-4px); border-color: var(--accent); }
.contact-icon {
  width: 30px; height: 30px; display: flex; align-items: center; justify-content: center;
  border-radius: 8px; background: rgba(255,154,0,0.1); color: var(--accent); margin-bottom: 4px;
}
.contact-icon svg { width: 15px; height: 15px; }
.contact-label { font-family: var(--mono); font-size: 0.76rem; color: var(--text-faint); text-transform: uppercase; letter-spacing: 0.05em; }
.contact-value { font-size: 1.02rem; font-weight: 500; }

/* footer */
footer { border-top: 1px solid var(--border); padding: 32px 0; }
.footer-inner { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 12px; }
.footer-inner p { color: var(--text-faint); font-size: 0.85rem; }
.footer-inner a { color: var(--text-faint); font-size: 0.85rem; transition: color .2s ease; }
.footer-inner a:hover { color: var(--accent); }

/* ---------- reveal animation ---------- */
.reveal { opacity: 0; transform: translateY(22px); transition: opacity .7s ease, transform .7s ease; }
.reveal.in-view { opacity: 1; transform: translateY(0); }

/* ---------- responsive ---------- */
@media (max-width: 980px) {
  .hero-grid { grid-template-columns: 1fr; }
  .hero-panel { order: -1; }
  .about-grid { grid-template-columns: 1fr; }
  .skills-grid { grid-template-columns: repeat(2, 1fr); }
  .projects-grid { grid-template-columns: repeat(2, 1fr); }
  .contact-grid { grid-template-columns: 1fr; }
}

@media (max-width: 680px) {
  .nav-links { position: fixed; top: 64px; left: 0; right: 0; background: var(--nav-bg-mobile);
    flex-direction: column; padding: 24px 28px; gap: 20px; border-bottom: 1px solid var(--border);
    transform: translateY(-140%); transition: transform .3s ease; }
  .nav-links.open { transform: translateY(0); }
  .nav-toggle {
    display: flex; flex-direction: column; gap: 5px; background: none; border: none; cursor: pointer; padding: 8px;
  }
  .nav-toggle span { width: 22px; height: 2px; background: var(--text); border-radius: 2px; }
  .hero-panel { width: min(100%, 440px); margin: 0 auto; }
  .model-card { width: 100%; max-width: 440px; }
  .model-card-body { font-size: 0.72rem; line-height: 1.6; padding: 16px 14px; }
  .skills-grid { grid-template-columns: 1fr; }
  .projects-grid { grid-template-columns: 1fr; }
  .hero { padding-top: 120px; }
}

@media (max-width: 400px) {
  .container { padding: 0 20px; }
  .nav-inner { padding: 14px 20px; }
  .nav-controls { gap: 6px; }
  .lang-btn { padding: 6px 9px; }
  .section { padding: 88px 0; }
  .hero { padding-top: 104px; padding-bottom: 56px; }
  .about-stats { grid-template-columns: 1fr 1fr; gap: 12px; }
  .stat-card { padding: 16px 14px; }
  .contact-grid { gap: 14px; }
  .model-card-body { font-size: 0.7rem; padding: 15px 12px; }
}

/* ---------- accessibility ---------- */
a:focus-visible, button:focus-visible {
  outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 4px;
}

@media (prefers-reduced-motion: reduce) {
  * { animation-duration: 0.001ms !important; animation-iteration-count: 1 !important; transition-duration: 0.001ms !important; scroll-behavior: auto !important; }
  .reveal { opacity: 1; transform: none; }
}