/* ============ Design tokens ============ */
:root {
  --accent-1: #22d3ee;
  --accent-2: #8b5cf6;
  --accent-3: #f472b6;
  --radius: 16px;
  --radius-sm: 10px;
  --container: 1120px;
  --shadow-soft: 0 20px 60px -20px rgba(0,0,0,.35);
  --transition: 220ms cubic-bezier(.4,0,.2,1);
}

:root[data-theme="dark"] {
  --bg: #0a0e17;
  --bg-alt: #0d1220;
  --surface: rgba(255,255,255,.04);
  --surface-strong: rgba(255,255,255,.07);
  --border: rgba(255,255,255,.09);
  --text: #eef1f8;
  --text-muted: #9aa4bd;
  --text-faint: #6b7591;
  --header-bg: rgba(10,14,23,.72);
}

:root[data-theme="light"] {
  --bg: #f7f8fc;
  --bg-alt: #ffffff;
  --surface: rgba(15,23,42,.035);
  --surface-strong: rgba(15,23,42,.06);
  --border: rgba(15,23,42,.09);
  --text: #12172a;
  --text-muted: #4c5673;
  --text-faint: #8189a3;
  --header-bg: rgba(247,248,252,.78);
}

@media (prefers-color-scheme: light) {
  :root:not([data-theme]) { color-scheme: light; }
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Inter, Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.6;
  transition: background var(--transition), color var(--transition);
}
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
ul { margin: 0; padding: 0; list-style: none; }
h1, h2, h3, h4 { line-height: 1.15; margin: 0; font-weight: 700; letter-spacing: -0.02em; }
p { margin: 0; }

.container {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}

.kicker {
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .12em;
  text-transform: uppercase;
  background: linear-gradient(90deg, var(--accent-1), var(--accent-2));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  margin: 0 0 10px;
}

/* ============ Header ============ */
#site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: transparent;
  transition: background var(--transition), box-shadow var(--transition), border-color var(--transition);
  border-bottom: 1px solid transparent;
}
#site-header.scrolled {
  background: var(--header-bg);
  -webkit-backdrop-filter: blur(14px) saturate(150%);
  backdrop-filter: blur(14px) saturate(150%);
  border-bottom: 1px solid var(--border);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}
.logo {
  font-weight: 800;
  font-size: 19px;
  letter-spacing: -0.02em;
}
.logo span {
  background: linear-gradient(90deg, var(--accent-1), var(--accent-2));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.nav-links {
  display: flex;
  gap: 30px;
}
.nav-links a {
  font-size: 14.5px;
  font-weight: 500;
  color: var(--text-muted);
  position: relative;
  padding: 6px 0;
  transition: color var(--transition);
}
.nav-links a:hover, .nav-links a.active { color: var(--text); }
.nav-links a.active::after {
  content: "";
  position: absolute;
  left: 0; right: 0; bottom: -2px;
  height: 2px;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--accent-1), var(--accent-2));
}
.header-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}
.icon-btn {
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  border-radius: 999px;
  padding: 8px 14px;
  font-size: 13px;
  font-weight: 700;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 6px;
  transition: background var(--transition), border-color var(--transition), transform var(--transition);
}
.icon-btn:hover { background: var(--surface-strong); transform: translateY(-1px); }
.theme-btn svg { width: 16px; height: 16px; }
.theme-label { display: none; }
@media (min-width: 640px) { .theme-label { display: inline; } }

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 4px;
  width: 34px;
  height: 34px;
  border: 1px solid var(--border);
  background: var(--surface);
  border-radius: 8px;
  align-items: center;
  justify-content: center;
  cursor: pointer;
}
.nav-toggle span {
  width: 16px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: transform var(--transition), opacity var(--transition);
}
.nav-toggle.open span:nth-child(1) { transform: translateY(6px) rotate(45deg); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

/* ============ Hero ============ */
.hero {
  position: relative;
  min-height: 92vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  overflow: hidden;
  padding: 90px 0 40px;
}
.hero-bg {
  position: absolute;
  inset: -20% -10%;
  z-index: -1;
  background:
    radial-gradient(38% 45% at 78% 18%, color-mix(in srgb, var(--accent-2) 32%, transparent), transparent 70%),
    radial-gradient(35% 40% at 15% 75%, color-mix(in srgb, var(--accent-1) 28%, transparent), transparent 70%),
    radial-gradient(30% 35% at 60% 90%, color-mix(in srgb, var(--accent-3) 18%, transparent), transparent 70%);
  filter: blur(10px);
  animation: drift 22s ease-in-out infinite alternate;
}
@keyframes drift {
  0% { transform: translate3d(0,0,0) scale(1); }
  100% { transform: translate3d(-2%, 2%, 0) scale(1.08); }
}
.hero-inner {
  display: grid;
  grid-template-columns: 1.3fr .9fr;
  gap: 56px;
  align-items: center;
}
.hero-role { font-size: 19px; font-weight: 600; color: var(--text-muted); margin-top: 14px; }
.hero-tagline { font-size: 17px; color: var(--text-muted); max-width: 52ch; margin-top: 14px; }
#hero-name {
  font-size: clamp(34px, 5.4vw, 56px);
  background: linear-gradient(120deg, var(--text) 30%, var(--accent-1) 65%, var(--accent-2) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.badge-row { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 22px; }
.badge {
  font-size: 12.5px;
  font-weight: 700;
  padding: 7px 13px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-muted);
}
.hero-cta-row { display: flex; gap: 14px; margin-top: 30px; flex-wrap: wrap; }
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 24px;
  border-radius: 999px;
  font-weight: 700;
  font-size: 14.5px;
  transition: transform var(--transition), box-shadow var(--transition), background var(--transition), border-color var(--transition);
  border: 1px solid transparent;
  cursor: pointer;
}
.btn-primary {
  background: linear-gradient(120deg, var(--accent-1), var(--accent-2));
  color: #05060a;
  box-shadow: 0 12px 30px -10px color-mix(in srgb, var(--accent-2) 60%, transparent);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 16px 36px -8px color-mix(in srgb, var(--accent-2) 65%, transparent); }
.btn-ghost { background: var(--surface); border-color: var(--border); color: var(--text); }
.btn-ghost:hover { background: var(--surface-strong); transform: translateY(-2px); }
.hero-socials { display: flex; gap: 16px; margin-top: 34px; }
.hero-socials a {
  width: 40px; height: 40px;
  display: flex; align-items: center; justify-content: center;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-muted);
  transition: color var(--transition), border-color var(--transition), transform var(--transition);
}
.hero-socials a:hover { color: var(--text); border-color: color-mix(in srgb, var(--accent-1) 50%, var(--border)); transform: translateY(-2px); }
.hero-socials svg { width: 18px; height: 18px; }

.hero-photo-wrap {
  position: relative;
  width: min(320px, 80vw);
  aspect-ratio: 1;
  justify-self: center;
}
.hero-photo-ring {
  position: absolute;
  inset: -14px;
  border-radius: 32%;
  background: conic-gradient(from 120deg, var(--accent-1), var(--accent-2), var(--accent-3), var(--accent-1));
  animation: spin 14s linear infinite;
  filter: blur(0.3px);
}
@keyframes spin { to { transform: rotate(360deg); } }
.hero-photo {
  position: relative;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: 50% 30%;
  border-radius: 30%;
  border: 5px solid var(--bg);
}

.scroll-cue {
  position: absolute;
  bottom: 28px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  font-size: 11px;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--text-faint);
}
.scroll-line {
  width: 1px;
  height: 34px;
  background: linear-gradient(var(--text-faint), transparent);
  animation: pulse 2s ease-in-out infinite;
}
@keyframes pulse { 0%,100% { opacity: .3; } 50% { opacity: 1; } }

/* ============ Sections ============ */
.section { padding: 110px 0; }
.section.alt { background: var(--bg-alt); }
.section h2 { font-size: clamp(28px, 3.6vw, 38px); margin-bottom: 46px; }
.section[id] { scroll-margin-top: 76px; }

/* About */
.about-grid { display: grid; grid-template-columns: 1.4fr 1fr; gap: 60px; }
.about-text p { color: var(--text-muted); font-size: 16.5px; margin-bottom: 18px; }
.about-facts { display: flex; flex-direction: column; gap: 18px; }
.fact {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 16px 18px;
  border-radius: var(--radius-sm);
  background: var(--surface);
  border: 1px solid var(--border);
}
.fact-label { font-size: 11.5px; text-transform: uppercase; letter-spacing: .08em; color: var(--text-faint); font-weight: 700; }
.fact-value { font-size: 14.5px; color: var(--text); font-weight: 600; }

/* Timeline (experience) */
.timeline { position: relative; padding-left: 30px; border-left: 2px solid var(--border); display: flex; flex-direction: column; gap: 44px; }
.timeline-item { position: relative; }
.timeline-dot {
  position: absolute; left: -37px; top: 4px;
  width: 12px; height: 12px; border-radius: 50%;
  background: linear-gradient(120deg, var(--accent-1), var(--accent-2));
  box-shadow: 0 0 0 4px var(--bg-alt);
}
.timeline-head { display: flex; flex-wrap: wrap; align-items: baseline; gap: 10px 16px; }
.timeline-head h3 { font-size: 19px; }
.timeline-period { font-size: 13px; font-weight: 700; color: var(--text-faint); }
.timeline-org { font-size: 15px; color: var(--text-muted); font-weight: 600; margin-top: 4px; }
.timeline-content ul { margin-top: 12px; display: flex; flex-direction: column; gap: 8px; }
.timeline-content li { color: var(--text-muted); font-size: 15px; padding-left: 18px; position: relative; }
.timeline-content li::before {
  content: "";
  position: absolute; left: 0; top: 9px;
  width: 6px; height: 6px; border-radius: 50%;
  background: var(--accent-1);
}

/* Education */
.edu-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); gap: 24px; }
.edu-card {
  padding: 26px;
  border-radius: var(--radius);
  background: var(--surface);
  border: 1px solid var(--border);
}
.edu-card p { margin-top: 14px; color: var(--text-muted); font-size: 14.5px; }

/* Skills */
.skills-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 20px; }
.skill-card {
  padding: 24px;
  border-radius: var(--radius);
  background: var(--surface);
  border: 1px solid var(--border);
  transition: transform var(--transition), border-color var(--transition);
}
.skill-card:hover { transform: translateY(-3px); border-color: color-mix(in srgb, var(--accent-1) 40%, var(--border)); }
.skill-card h3 { font-size: 15px; margin-bottom: 14px; color: var(--text); }
.pill-wrap { display: flex; flex-wrap: wrap; gap: 8px; }
.pill {
  font-size: 12.5px;
  font-weight: 600;
  padding: 6px 12px;
  border-radius: 999px;
  background: var(--surface-strong);
  color: var(--text-muted);
  border: 1px solid var(--border);
}

/* Projects */
.filter-row { display: flex; flex-wrap: wrap; gap: 10px; margin-bottom: 36px; }
.filter-btn {
  padding: 9px 18px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-muted);
  font-weight: 700;
  font-size: 13.5px;
  cursor: pointer;
  transition: all var(--transition);
}
.filter-btn:hover { color: var(--text); }
.filter-btn.active {
  background: linear-gradient(120deg, var(--accent-1), var(--accent-2));
  color: #05060a;
  border-color: transparent;
}
.projects-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 22px; }
.project-card {
  padding: 26px;
  border-radius: var(--radius);
  background: var(--surface);
  border: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: 14px;
  transition: transform var(--transition), border-color var(--transition), box-shadow var(--transition);
}
.project-card:hover { transform: translateY(-4px); border-color: color-mix(in srgb, var(--accent-2) 40%, var(--border)); box-shadow: var(--shadow-soft); }
.project-top { display: flex; flex-direction: column; gap: 8px; }
.project-top h3 { font-size: 17.5px; }
.project-top h3 a {
  color: inherit;
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--transition), border-color var(--transition);
}
.project-top h3 a:hover { color: var(--accent-1); border-color: color-mix(in srgb, var(--accent-1) 50%, transparent); }
.project-card p { color: var(--text-muted); font-size: 14.5px; flex: 1; }
.confidential-tag {
  font-size: 11.5px;
  font-weight: 700;
  color: var(--text-faint);
  width: fit-content;
}
.tag-wrap { display: flex; flex-wrap: wrap; gap: 7px; }
.tag {
  font-size: 11.5px;
  font-weight: 700;
  padding: 5px 10px;
  border-radius: 6px;
  background: var(--surface-strong);
  color: var(--text-muted);
}

/* Certifications */
.cert-group { margin-bottom: 40px; }
.cert-group:last-child { margin-bottom: 0; }
.cert-group-header {
  display: flex;
  align-items: baseline;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 16px;
}
.cert-group-header h3 { font-size: 17px; }
.cert-group-summary { font-size: 13px; color: var(--text-faint); font-weight: 600; }
.cert-group-note { font-size: 12.5px; color: var(--text-faint); margin: 10px 0 0; font-style: italic; }
.cert-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 16px; margin-bottom: 16px; }
.cert-card {
  padding: 20px;
  border-radius: var(--radius-sm);
  background: var(--surface);
  border: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: 8px;
  color: inherit;
  text-decoration: none;
  transition: border-color var(--transition), transform var(--transition);
}
a.cert-card:hover { border-color: color-mix(in srgb, var(--accent-1) 40%, var(--border)); transform: translateY(-2px); }
.cert-card h4 { font-size: 14.5px; }
.cert-card span { font-size: 12.5px; color: var(--text-faint); font-weight: 700; }
.credly-link {
  display: inline-flex;
  font-weight: 700;
  font-size: 14px;
  color: var(--accent-1);
  border-bottom: 1px solid color-mix(in srgb, var(--accent-1) 40%, transparent);
  width: fit-content;
}

/* Leadership */
.leadership-text { color: var(--text-muted); font-size: 16px; max-width: 72ch; margin-bottom: 34px; }
.languages-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 16px; }
.lang-item {
  padding: 16px 18px;
  border-radius: var(--radius-sm);
  background: var(--surface);
  border: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.lang-item strong { font-size: 15px; }
.lang-item span { font-size: 13px; color: var(--text-muted); }

/* Contact */
.contact-section { text-align: center; }
.contact-text { color: var(--text-muted); font-size: 17px; max-width: 60ch; margin: 0 auto 34px; }
#contact-email-btn { margin: 0 auto; }
.contact-links { margin-top: 44px; display: flex; flex-direction: column; align-items: center; gap: 16px; }
.contact-links > span { font-size: 13px; font-weight: 700; letter-spacing: .06em; text-transform: uppercase; color: var(--text-faint); }
.contact-icons { display: flex; gap: 16px; }
.contact-icons a {
  width: 44px; height: 44px;
  display: flex; align-items: center; justify-content: center;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-muted);
  transition: all var(--transition);
}
.contact-icons a:hover { color: var(--text); transform: translateY(-2px); border-color: color-mix(in srgb, var(--accent-1) 50%, var(--border)); }
.contact-icons svg { width: 19px; height: 19px; }

/* Footer */
#site-footer { border-top: 1px solid var(--border); padding: 30px 0; }
.footer-inner { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 12px; font-size: 13.5px; color: var(--text-faint); }
#footer-source { font-weight: 700; color: var(--text-muted); }
#footer-source:hover { color: var(--text); }

/* ============ Responsive ============ */
@media (max-width: 900px) {
  .hero-inner { grid-template-columns: 1fr; text-align: center; }
  .hero-photo-wrap { order: -1; width: min(220px, 60vw); }
  .hero-cta-row, .hero-socials, .badge-row { justify-content: center; }
  .about-grid { grid-template-columns: 1fr; gap: 34px; }
}

@media (max-width: 760px) {
  .nav-toggle { display: flex; }
  nav .nav-links {
    position: fixed;
    inset: 68px 0 0 0;
    background: var(--header-bg);
    -webkit-backdrop-filter: blur(16px);
    backdrop-filter: blur(16px);
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 30px;
    transform: translateY(-12px);
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition), transform var(--transition);
  }
  .nav-links.open { opacity: 1; transform: none; pointer-events: auto; }
  .nav-links a { font-size: 20px; }
  .section { padding: 76px 0; }
}