:root {
  --color-bg: #0b1220;
  --color-bg-alt: #101a2e;
  --color-surface: #16213a;
  --color-border: #223154;
  --color-text: #e8ecf5;
  --color-text-muted: #a7b2c9;
  --color-primary: #3d8bff;
  --color-primary-dark: #2a6fe0;
  --color-accent: #5fe3c0;
  --max-width: 1120px;
  --radius: 10px;
  --font: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

@media (prefers-color-scheme: light) {
  :root {
    --color-bg: #f7f9fc;
    --color-bg-alt: #ffffff;
    --color-surface: #ffffff;
    --color-border: #e3e8f2;
    --color-text: #14192b;
    --color-text-muted: #565f78;
    --color-primary: #2a6fe0;
    --color-primary-dark: #1f57b8;
    --color-accent: #0e9c78;
  }
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font);
  background: var(--color-bg);
  color: var(--color-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; }

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: color-mix(in srgb, var(--color-bg) 85%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.logo {
  font-weight: 800;
  font-size: 1.25rem;
  letter-spacing: -0.02em;
}

.logo-dot { color: var(--color-primary); }

.nav {
  display: flex;
  gap: 32px;
}

.nav a {
  font-weight: 500;
  font-size: 0.95rem;
  color: var(--color-text-muted);
  transition: color 0.15s ease;
}

.nav a:hover { color: var(--color-text); }

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}

.nav-toggle span {
  width: 22px;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
}

/* Hero */
.hero {
  padding: 120px 0 100px;
  background:
    radial-gradient(circle at 15% 20%, color-mix(in srgb, var(--color-primary) 18%, transparent), transparent 55%),
    radial-gradient(circle at 85% 0%, color-mix(in srgb, var(--color-accent) 14%, transparent), transparent 50%);
}

.hero-inner { max-width: 720px; }

.eyebrow {
  color: var(--color-primary);
  font-weight: 600;
  font-size: 0.95rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin-bottom: 16px;
}

.hero h1 {
  font-size: clamp(2.4rem, 5vw, 3.6rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  margin-bottom: 20px;
}

.hero-subtitle {
  font-size: 1.15rem;
  color: var(--color-text-muted);
  margin-bottom: 36px;
  max-width: 600px;
}

.hero-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  padding: 13px 26px;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 0.95rem;
  transition: transform 0.15s ease, background 0.15s ease, border-color 0.15s ease;
}

.btn:hover { transform: translateY(-2px); }

.btn-primary {
  background: var(--color-primary);
  color: #fff;
}

.btn-primary:hover { background: var(--color-primary-dark); }

.btn-secondary {
  border: 1px solid var(--color-border);
  color: var(--color-text);
}

.btn-secondary:hover { border-color: var(--color-primary); }

/* Sections */
.section { padding: 96px 0; }

.section:nth-of-type(even) { background: var(--color-bg-alt); }

.section-title {
  font-size: clamp(1.7rem, 3vw, 2.2rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 44px;
}

.subsection-title {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 24px;
}

/* About */
.about-content {
  max-width: 760px;
  display: flex;
  flex-direction: column;
  gap: 20px;
  font-size: 1.05rem;
  color: var(--color-text-muted);
}

/* Skills */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 24px;
}

.skill-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 28px;
  transition: border-color 0.15s ease, transform 0.15s ease;
}

.skill-card:hover {
  border-color: var(--color-primary);
  transform: translateY(-3px);
}

.skill-card h3 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 10px;
}

.skill-card p {
  color: var(--color-text-muted);
  font-size: 0.95rem;
}

/* Timeline */
.timeline {
  list-style: none;
  position: relative;
  padding-left: 32px;
  margin-bottom: 64px;
}

.timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 6px;
  bottom: 6px;
  width: 2px;
  background: var(--color-border);
}

.timeline-item {
  position: relative;
  padding-bottom: 36px;
}

.timeline-item:last-child { padding-bottom: 0; }

.timeline-marker {
  position: absolute;
  left: -32px;
  top: 4px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--color-primary);
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--color-primary) 20%, transparent);
}

.timeline-content h3 {
  font-size: 1.15rem;
  font-weight: 700;
}

.timeline-org {
  color: var(--color-primary);
  font-weight: 600;
  font-size: 0.9rem;
  margin-bottom: 8px;
}

.timeline-content p:not(.timeline-org) {
  color: var(--color-text-muted);
  max-width: 620px;
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding: 32px 0;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  color: var(--color-text-muted);
  font-size: 0.9rem;
}

.footer-linkedin {
  display: inline-flex;
  color: var(--color-text-muted);
  transition: color 0.15s ease;
}

.footer-linkedin:hover { color: var(--color-primary); }

/* Responsive */
@media (max-width: 720px) {
  .nav {
    display: none;
    position: absolute;
    top: 72px;
    left: 0;
    right: 0;
    flex-direction: column;
    gap: 0;
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    padding: 8px 24px 16px;
  }
  .nav.nav-open { display: flex; }
  .nav a { padding: 12px 0; border-bottom: 1px solid var(--color-border); }
  .nav a:last-child { border-bottom: none; }
  .nav-toggle { display: flex; }
  .hero { padding: 90px 0 70px; }
  .section { padding: 64px 0; }
}