/* ==========================================================================
   Design tokens
   ========================================================================== */
:root {
  --font-display: "Space Grotesk", system-ui, sans-serif;
  --font-body: "Inter", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, "SF Mono", Menlo, monospace;

  --radius-sm: 8px;
  --radius: 14px;
  --radius-lg: 20px;

  --container: 1080px;
  --header-h: 64px;

  --ease-out: cubic-bezier(0.22, 1, 0.36, 1);
  --dur: 200ms;

  --z-header: 40;
  --z-skip: 100;
}

/* Dark (default) */
:root,
[data-theme="dark"] {
  color-scheme: dark;
  --bg: #0b0f17;
  --bg-elev: #111723;
  --surface: #141b29;
  --surface-hover: #1a2334;
  --border: #243044;
  --text: #e6eaf2;
  --text-muted: #9aa6b8;
  --accent: #60a5fa;
  --accent-strong: #93c5fd;
  --accent-soft: rgba(96, 165, 250, 0.12);
  --on-accent: #0b0f17;
  --success: #34d399;
  --glow: rgba(96, 165, 250, 0.18);
  --header-bg: rgba(11, 15, 23, 0.78);
}

[data-theme="light"] {
  color-scheme: light;
  --bg: #f8fafc;
  --bg-elev: #ffffff;
  --surface: #ffffff;
  --surface-hover: #f1f5f9;
  --border: #e2e8f0;
  --text: #0f172a;
  --text-muted: #475569;
  --accent: #2563eb;
  --accent-strong: #1d4ed8;
  --accent-soft: rgba(37, 99, 235, 0.08);
  --on-accent: #ffffff;
  --success: #059669;
  --glow: rgba(37, 99, 235, 0.10);
  --header-bg: rgba(248, 250, 252, 0.82);
}

/* ==========================================================================
   Base
   ========================================================================== */
*,
*::before,
*::after { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 16px);
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  transition: background-color var(--dur) ease, color var(--dur) ease;
}

h1, h2, h3 {
  font-family: var(--font-display);
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin: 0;
}

p { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }

a {
  color: var(--accent);
  text-decoration: none;
  transition: color var(--dur) ease;
}
a:hover { color: var(--accent-strong); }

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 4px;
}

.mono { font-family: var(--font-mono); }

.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: 20px;
}

.icon {
  width: 20px;
  height: 20px;
  flex: none;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.75;
  stroke-linecap: round;
  stroke-linejoin: round;
}
.icon-lg { width: 28px; height: 28px; }

.skip-link {
  position: absolute;
  left: 16px;
  top: -100px;
  z-index: var(--z-skip);
  padding: 10px 16px;
  background: var(--accent);
  color: var(--on-accent);
  border-radius: var(--radius-sm);
  font-weight: 600;
}
.skip-link:focus { top: 12px; color: var(--on-accent); }

main:focus { outline: none; }

/* ==========================================================================
   Header
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: var(--z-header);
  height: var(--header-h);
  background: var(--header-bg);
  backdrop-filter: saturate(160%) blur(12px);
  -webkit-backdrop-filter: saturate(160%) blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--dur) ease, background-color var(--dur) ease;
}
.site-header.scrolled { border-bottom-color: var(--border); }

.header-inner {
  height: 100%;
  display: flex;
  align-items: center;
  gap: 16px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  font-family: var(--font-display);
  font-weight: 600;
  min-height: 44px;
}
.brand:hover { color: var(--text); }
.brand-mark {
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  border-radius: 10px;
  background: var(--accent);
  color: var(--on-accent);
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 500;
  letter-spacing: -0.04em;
}

.nav { margin-left: auto; }
.nav ul { display: flex; gap: 4px; }
.nav a {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  padding: 0 12px;
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  font-size: 0.92rem;
  font-weight: 500;
  transition: color var(--dur) ease, background-color var(--dur) ease;
}
.nav a:hover { color: var(--text); background: var(--surface-hover); }
.nav a[aria-current="true"] { color: var(--text); }
.nav a[aria-current="true"]::after {
  content: "";
  display: block;
  width: 4px;
  height: 4px;
  margin-left: 6px;
  border-radius: 50%;
  background: var(--accent);
}

.controls {
  display: flex;
  align-items: center;
  gap: 8px;
}

.lang-switch {
  display: inline-flex;
  padding: 3px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--bg-elev);
}
.lang-btn {
  min-width: 40px;
  min-height: 36px;
  padding: 0 8px;
  border: 0;
  border-radius: 7px;
  background: transparent;
  color: var(--text-muted);
  font: 500 0.78rem var(--font-mono);
  cursor: pointer;
  transition: background-color var(--dur) ease, color var(--dur) ease;
}
.lang-btn:hover { color: var(--text); }
.lang-btn[aria-pressed="true"] {
  background: var(--accent-soft);
  color: var(--accent);
}

.icon-btn {
  display: inline-grid;
  place-items: center;
  width: 44px;
  height: 44px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--bg-elev);
  color: var(--text);
  cursor: pointer;
  transition: background-color var(--dur) ease, border-color var(--dur) ease, transform 120ms ease;
}
.icon-btn:hover { background: var(--surface-hover); }
.icon-btn:active { transform: scale(0.96); }

[data-theme="dark"] .icon-moon,
[data-theme="light"] .icon-sun { display: none; }

.menu-btn { display: none; }

/* ==========================================================================
   Buttons
   ========================================================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 46px;
  padding: 0 20px;
  border-radius: 12px;
  border: 1px solid transparent;
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  transition: background-color var(--dur) ease, border-color var(--dur) ease,
              color var(--dur) ease, transform 120ms ease, box-shadow var(--dur) ease;
}
.btn:active { transform: scale(0.98); }
.btn-lg { min-height: 54px; padding: 0 26px; font-size: 1rem; }

.btn-primary {
  background: var(--accent);
  color: var(--on-accent);
  box-shadow: 0 8px 24px -10px var(--accent);
}
.btn-primary:hover {
  background: var(--accent-strong);
  color: var(--on-accent);
}

.btn-ghost {
  border-color: var(--border);
  color: var(--text);
  background: var(--bg-elev);
}
.btn-ghost:hover {
  color: var(--text);
  border-color: var(--accent);
  background: var(--surface-hover);
}

/* ==========================================================================
   Hero
   ========================================================================== */
.hero {
  position: relative;
  overflow: hidden;
  padding: clamp(72px, 14vw, 140px) 0 clamp(56px, 10vw, 104px);
}
.hero::before {
  content: "";
  position: absolute;
  inset: -20% -10% auto auto;
  width: 640px;
  height: 640px;
  background: radial-gradient(circle, var(--glow), transparent 65%);
  pointer-events: none;
}
.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--border) 1px, transparent 1px),
    linear-gradient(90deg, var(--border) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(ellipse 70% 60% at 70% 30%, #000 10%, transparent 70%);
  -webkit-mask-image: radial-gradient(ellipse 70% 60% at 70% 30%, #000 10%, transparent 70%);
  opacity: 0.45;
  pointer-events: none;
}
.hero-inner { position: relative; z-index: 1; }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 6px 14px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--bg-elev);
  color: var(--text-muted);
  font-size: 0.8rem;
}
.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--success);
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--success) 20%, transparent);
}

.hero-title {
  margin-top: 28px;
  max-width: 18ch;
  font-size: clamp(2.4rem, 6.5vw, 4.4rem);
  font-weight: 700;
  letter-spacing: -0.035em;
}
.accent-text { color: var(--text-muted); }

.hero-lead {
  margin-top: 24px;
  max-width: 62ch;
  color: var(--text-muted);
  font-size: clamp(1.05rem, 1.6vw, 1.2rem);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 36px;
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 28px;
  margin-top: 40px;
  color: var(--text-muted);
  font-size: 0.85rem;
}
.hero-meta li { display: inline-flex; align-items: center; gap: 8px; }
.hero-meta .icon { width: 18px; height: 18px; }

/* ==========================================================================
   Sections
   ========================================================================== */
.section { padding: clamp(64px, 10vw, 112px) 0; }
.section + .section { border-top: 1px solid var(--border); }

.section-head {
  display: flex;
  align-items: baseline;
  gap: 16px;
  margin-bottom: 40px;
}
.section-index {
  color: var(--accent);
  font-size: 0.85rem;
}
.section-head h2 { font-size: clamp(1.8rem, 4vw, 2.5rem); }

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  transition: border-color var(--dur) ease, background-color var(--dur) ease, transform var(--dur) var(--ease-out);
}

/* About */
.about-grid {
  display: grid;
  grid-template-columns: 1.6fr 1fr;
  gap: 48px;
  align-items: start;
}
.about-text p + p { margin-top: 16px; }
.about-text p { color: var(--text-muted); font-size: 1.08rem; max-width: 64ch; }

.stats {
  display: grid;
  gap: 12px;
  margin: 0;
}
.stat {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding: 16px 20px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
}
.stat dt { color: var(--text-muted); font-size: 0.92rem; }
.stat dd {
  margin: 0;
  font-family: var(--font-display);
  font-size: 2rem;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  color: var(--text);
}

.highlights {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  margin-top: 48px;
}
.highlights .icon { color: var(--accent); }
.highlights h3 { margin-top: 16px; font-size: 1.08rem; }
.highlights p { margin-top: 8px; color: var(--text-muted); font-size: 0.93rem; line-height: 1.55; }
.highlights .card:hover { border-color: color-mix(in srgb, var(--accent) 45%, var(--border)); }

/* Experience */
.timeline { position: relative; }
.job {
  display: grid;
  grid-template-columns: 180px 1fr;
  gap: 32px;
  padding: 28px 0;
  position: relative;
}
.job + .job { border-top: 1px dashed var(--border); }
.job-when {
  color: var(--text-muted);
  font-size: 0.82rem;
  padding-top: 4px;
}
.job h3 { font-size: 1.22rem; }
.job .at { color: var(--accent); font-weight: 500; }
.job-points { margin-top: 14px; display: grid; gap: 8px; }
.job-points li {
  position: relative;
  padding-left: 20px;
  color: var(--text-muted);
}
.job-points li::before {
  content: "";
  position: absolute;
  left: 2px;
  top: 0.72em;
  width: 8px;
  height: 1.5px;
  background: var(--accent);
}

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 16px;
}
.tags li {
  padding: 4px 10px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--bg-elev);
  color: var(--text);
  font-family: var(--font-mono);
  font-size: 0.76rem;
  line-height: 1.6;
}

/* Skills */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}
.skill-group h3 { font-size: 1.02rem; }
.skill-group .tags { margin-top: 14px; }

/* Education */
.edu-list {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}
.edu-when { color: var(--accent); font-size: 0.8rem; }
.edu h3 { margin-top: 10px; font-size: 1.08rem; }
.edu p:last-child { margin-top: 6px; color: var(--text-muted); font-size: 0.95rem; }

/* Contact */
.contact { border-top: 1px solid var(--border); }
.contact-card {
  position: relative;
  overflow: hidden;
  padding: clamp(36px, 7vw, 72px);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background:
    radial-gradient(600px 300px at 100% 0%, var(--glow), transparent 70%),
    var(--surface);
  text-align: center;
}
.contact-card h2 {
  margin-top: 12px;
  font-size: clamp(2rem, 5vw, 3rem);
}
.contact-lead {
  max-width: 52ch;
  margin: 16px auto 32px;
  color: var(--text-muted);
  font-size: 1.08rem;
}
.socials {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px;
  margin-top: 28px;
}
.social {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 44px;
  padding: 0 16px;
  border-radius: 10px;
  color: var(--text-muted);
  font-weight: 500;
  transition: color var(--dur) ease, background-color var(--dur) ease;
}
.social:hover { color: var(--text); background: var(--surface-hover); }

/* Footer */
.site-footer {
  padding: 28px 0 36px;
  color: var(--text-muted);
  font-size: 0.82rem;
}
.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
}
.to-top {
  color: var(--text-muted);
  min-height: 44px;
  display: inline-flex;
  align-items: center;
}
.to-top:hover { color: var(--text); }

/* ==========================================================================
   Reveal on scroll (only when JS is running and motion is allowed)
   ========================================================================== */
.js .reveal {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 500ms var(--ease-out), transform 500ms var(--ease-out);
}
.js .reveal.visible { opacity: 1; transform: none; }

/* Text crossfade when switching language */
.i18n-fade [data-i18n] { transition: opacity 150ms ease; }
.i18n-switching [data-i18n] { opacity: 0; }

/* ==========================================================================
   Responsive
   ========================================================================== */
@media (max-width: 960px) {
  .highlights { grid-template-columns: repeat(2, 1fr); }
  .skills-grid { grid-template-columns: repeat(2, 1fr); }
  .edu-list { grid-template-columns: 1fr; }
  .about-grid { grid-template-columns: 1fr; gap: 32px; }
  .stats { grid-template-columns: repeat(3, 1fr); }
  .stat { flex-direction: column-reverse; align-items: flex-start; gap: 2px; }
}

@media (max-width: 820px) {
  .menu-btn { display: inline-grid; }
  .brand-name { display: none; }
  .nav {
    position: fixed;
    inset: var(--header-h) 0 auto 0;
    margin: 0;
    padding: 12px 20px 20px;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    transform: translateY(-8px);
    opacity: 0;
    visibility: hidden;
    transition: opacity var(--dur) ease, transform var(--dur) var(--ease-out), visibility 0s linear var(--dur);
  }
  .nav.open {
    opacity: 1;
    transform: none;
    visibility: visible;
    transition: opacity var(--dur) ease, transform var(--dur) var(--ease-out);
  }
  .nav ul { flex-direction: column; gap: 2px; }
  .nav a { min-height: 48px; font-size: 1rem; width: 100%; }
  .controls { margin-left: auto; }

  .job { grid-template-columns: 1fr; gap: 8px; }
}

@media (max-width: 560px) {
  .container { padding-inline: 16px; }
  .highlights, .skills-grid { grid-template-columns: 1fr; }
  .stats { grid-template-columns: 1fr; }
  .stat { flex-direction: row; align-items: baseline; }
  .hero-actions .btn { flex: 1 1 100%; }
  .btn-lg { width: 100%; font-size: 0.92rem; padding: 0 16px; }
  .footer-inner { flex-direction: column; text-align: center; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }
  .js .reveal { opacity: 1; transform: none; }
}

@media print {
  .site-header, .hero::before, .hero::after, .hero-actions, .socials, .site-footer { display: none; }
  .section { padding: 24px 0; }
}