:root {
  --navy-950: #0a0f1f;
  --navy-900: #0f1729;
  --navy-800: #14213d;
  --navy-700: #1c2c4f;
  --navy-600: #263a63;
  --accent: #4da3ff;
  --accent-2: #7de0c9;
  --text: #e8edf7;
  --text-dim: #a9b4cc;
  --text-faint: #7280a0;
  --border: rgba(255, 255, 255, 0.08);
  --card: rgba(255, 255, 255, 0.03);
  --radius: 14px;
  --max-width: 1120px;
  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font);
  background: var(--navy-950);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

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

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

img { max-width: 100%; display: block; }

/* Progress bar */
.progress-bar {
  position: fixed;
  top: 0; left: 0;
  height: 3px;
  width: 0%;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  z-index: 1000;
  transition: width 0.1s ease-out;
}

/* Header */
.header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  background: rgba(10, 15, 31, 0.7);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s ease, background 0.3s ease;
}
.header.scrolled {
  border-bottom-color: var(--border);
  background: rgba(10, 15, 31, 0.9);
}
.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}
.logo {
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: -0.02em;
}
.logo span { color: var(--accent); }

.nav {
  display: flex;
  gap: 32px;
}
.nav__link {
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--text-dim);
  position: relative;
  padding: 4px 0;
  transition: color 0.2s ease;
}
.nav__link:hover, .nav__link.active { color: var(--text); }
.nav__link::after {
  content: '';
  position: absolute;
  left: 0; bottom: -2px;
  width: 0;
  height: 2px;
  background: var(--accent);
  transition: width 0.25s ease;
}
.nav__link:hover::after, .nav__link.active::after { width: 100%; }

.header__cta { font-size: 0.88rem; padding: 9px 18px; }

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 36px;
  height: 36px;
  background: none;
  border: none;
  cursor: pointer;
}
.nav-toggle span {
  width: 100%;
  height: 2px;
  background: var(--text);
  transition: transform 0.25s ease, opacity 0.25s ease;
}
.nav-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 26px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.95rem;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease, border-color 0.2s ease;
}
.btn--primary {
  background: linear-gradient(135deg, var(--accent), #2e7fe0);
  color: #08101f;
}
.btn--primary:hover { transform: translateY(-2px); box-shadow: 0 10px 30px rgba(77, 163, 255, 0.35); }
.btn--outline {
  border-color: var(--border);
  color: var(--text);
}
.btn--outline:hover { border-color: var(--accent); background: rgba(77, 163, 255, 0.08); transform: translateY(-2px); }
.btn--ghost {
  color: var(--text);
  border-color: var(--border);
}
.btn--ghost:hover { background: var(--card); }

/* Hero */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  overflow: hidden;
  padding-top: 72px;
}
.hero__bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(700px circle at 15% 20%, rgba(77, 163, 255, 0.18), transparent 60%),
    radial-gradient(600px circle at 85% 70%, rgba(125, 224, 201, 0.12), transparent 55%),
    linear-gradient(180deg, var(--navy-950), var(--navy-900) 60%, var(--navy-950));
  z-index: -1;
}
.hero__inner { padding-top: 60px; padding-bottom: 60px; }

.eyebrow {
  display: inline-block;
  color: var(--accent);
  font-weight: 600;
  font-size: 0.92rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin-bottom: 18px;
}

.hero__title {
  font-size: clamp(2.6rem, 6vw, 4.5rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  margin: 0 0 18px;
  background: linear-gradient(180deg, #ffffff, #b9c6e6);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero__subtitle {
  max-width: 620px;
  font-size: 1.15rem;
  color: var(--text-dim);
  margin: 0 0 36px;
}

.hero__actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 48px;
}

.hero__meta {
  display: flex;
  gap: 28px;
  flex-wrap: wrap;
  font-size: 0.92rem;
  color: var(--text-faint);
}
.hero__meta li { display: flex; align-items: center; gap: 8px; }
.hero__meta a:hover { color: var(--accent); }
.icon { color: var(--accent); }

/* Sections */
.section { padding: 110px 0; }
.section--alt { background: var(--navy-900); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }

.section-label {
  color: var(--accent);
  font-weight: 600;
  font-size: 0.85rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin: 0 0 12px;
}
.section-title {
  font-size: clamp(1.8rem, 3.5vw, 2.6rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  margin: 0 0 48px;
}

/* About */
.about__text {
  max-width: 780px;
  font-size: 1.08rem;
  color: var(--text-dim);
  margin-bottom: 60px;
}

.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}
.stat {
  padding: 28px 20px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  text-align: center;
}
.stat__number {
  font-size: 2.4rem;
  font-weight: 800;
  color: var(--accent);
}
.stat__suffix { font-size: 2.4rem; font-weight: 800; color: var(--accent); }
.stat__label {
  display: block;
  margin-top: 8px;
  font-size: 0.88rem;
  color: var(--text-faint);
}

/* Skills */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
}
.skill-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 26px;
  transition: transform 0.25s ease, border-color 0.25s ease;
}
.skill-card:hover { transform: translateY(-4px); border-color: rgba(77, 163, 255, 0.35); }
.skill-card h3 {
  margin: 0 0 16px;
  font-size: 1.05rem;
  font-weight: 700;
}
.tags { display: flex; flex-wrap: wrap; gap: 8px; }
.tag {
  font-size: 0.82rem;
  padding: 6px 12px;
  border-radius: 999px;
  background: rgba(77, 163, 255, 0.1);
  color: var(--accent);
  border: 1px solid rgba(77, 163, 255, 0.2);
}

/* Timeline */
.timeline {
  position: relative;
  padding-left: 32px;
  border-left: 2px solid var(--border);
}
.timeline__item {
  position: relative;
  padding-bottom: 52px;
}
.timeline__item:last-child { padding-bottom: 0; }
.timeline__dot {
  position: absolute;
  left: -39px;
  top: 4px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--navy-950);
  border: 3px solid var(--accent);
}
.timeline__date {
  display: inline-block;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--accent-2);
  letter-spacing: 0.03em;
  text-transform: uppercase;
  margin-bottom: 8px;
}
.timeline__content h3 {
  margin: 0 0 4px;
  font-size: 1.3rem;
  font-weight: 700;
}
.timeline__org {
  color: var(--text-faint);
  font-size: 0.95rem;
  margin: 0 0 16px;
}
.timeline__content ul { margin-bottom: 16px; }
.timeline__content li {
  position: relative;
  padding-left: 20px;
  color: var(--text-dim);
  font-size: 0.96rem;
  margin-bottom: 8px;
}
.timeline__content li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 10px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
}
.timeline__highlight {
  background: rgba(125, 224, 201, 0.08);
  border-left: 3px solid var(--accent-2);
  padding: 12px 16px;
  border-radius: 6px;
  font-size: 0.93rem;
  color: #cfe9df;
  margin: 0;
}

/* Education */
.edu-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 20px;
}
.edu-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
}
.edu-card h3 { margin: 0 0 8px; font-size: 1.1rem; font-weight: 700; }
.edu-card__org { color: var(--text-dim); margin: 0 0 4px; font-size: 0.95rem; }
.edu-card__date { color: var(--text-faint); font-size: 0.88rem; margin: 0; }
.cert-list li {
  padding: 8px 0;
  border-bottom: 1px solid var(--border);
  color: var(--text-dim);
  font-size: 0.95rem;
}
.cert-list li:last-child { border-bottom: none; }

/* Contact */
.contact { text-align: center; }
.contact .section-title { margin-bottom: 18px; }
.contact__text {
  max-width: 560px;
  margin: 0 auto 40px;
  color: var(--text-dim);
  font-size: 1.05rem;
}
.contact__links {
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
}

/* 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;
  color: var(--text-faint);
  font-size: 0.88rem;
}
.footer__top { color: var(--text-dim); transition: color 0.2s ease; }
.footer__top:hover { color: var(--accent); }

/* Reveal animation */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}
.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* Responsive */
@media (max-width: 860px) {
  .nav, .header__cta { display: none; }
  .nav-toggle { display: flex; }
  .nav.mobile-open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 72px;
    left: 0; right: 0;
    background: var(--navy-900);
    border-bottom: 1px solid var(--border);
    padding: 20px 24px;
    gap: 18px;
  }
  .stats { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 560px) {
  .section { padding: 80px 0; }
  .hero__meta { flex-direction: column; gap: 12px; }
  .timeline { padding-left: 24px; }
  .timeline__dot { left: -31px; }
}