:root {
  --ink: #172533;
  --muted: #5d6b78;
  --paper: #fbfaf7;
  --surface: #ffffff;
  --surface-soft: #f4f1ea;
  --line: #d9dee3;
  --accent: #245f87;
  --accent-deep: #18364f;
  --accent-soft: #e6f0f6;
  --serif: Georgia, "Times New Roman", Times, serif;
  --sans: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --shadow: 0 18px 45px rgba(24, 54, 79, 0.10);
  --max: 1040px;
  --reading: 720px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.68;
  text-rendering: optimizeLegibility;
}

a {
  color: var(--accent);
  text-decoration-thickness: 0.08em;
  text-underline-offset: 0.18em;
}
a:hover { color: var(--accent-deep); }
img { display: block; max-width: 100%; }

.skip-link {
  position: fixed;
  top: -5rem;
  left: 1rem;
  z-index: 300;
  padding: 0.7rem 1rem;
  border: 1px solid var(--line);
  border-radius: 0.45rem;
  background: var(--surface);
}
.skip-link:focus { top: 1rem; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  border-bottom: 1px solid rgba(217, 222, 227, 0.9);
  background: rgba(251, 250, 247, 0.94);
  backdrop-filter: blur(14px);
}
.nav-wrap {
  width: min(var(--max), calc(100% - 3rem));
  min-height: 4.3rem;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.72rem;
  color: var(--ink);
  text-decoration: none;
}
.brand-mark {
  display: grid;
  width: 2.15rem;
  height: 2.15rem;
  place-items: center;
  border-radius: 0.45rem;
  color: #fff;
  background: var(--accent-deep);
  font-family: var(--serif);
  font-weight: 700;
}
.brand-text {
  font-family: var(--serif);
  font-weight: 700;
  letter-spacing: 0.01em;
  white-space: nowrap;
}
.nav-links {
  display: flex;
  align-items: center;
  gap: 0.18rem;
}
.nav-links a {
  padding: 0.5rem 0.68rem;
  border-radius: 0.4rem;
  color: var(--muted);
  font-size: 0.93rem;
  font-weight: 650;
  text-decoration: none;
}
.nav-links a:hover,
.nav-links a[aria-current="page"] {
  color: var(--accent-deep);
  background: var(--accent-soft);
}
.menu-button {
  display: none;
  padding: 0.52rem 0.72rem;
  border: 1px solid var(--line);
  border-radius: 0.45rem;
  color: var(--ink);
  background: var(--surface);
  font: inherit;
}

main { min-height: 70vh; }
.container {
  width: min(var(--max), calc(100% - 3rem));
  margin-inline: auto;
}
.narrow {
  width: min(var(--reading), calc(100% - 3rem));
  margin-inline: auto;
}
.section { padding: 4.75rem 0; }
.section.compact { padding: 3.5rem 0; }
.section-rule { border-top: 1px solid var(--line); }

h1, h2, h3 {
  color: var(--accent-deep);
  font-family: var(--serif);
  line-height: 1.16;
}
h1, h2, h3, p { overflow-wrap: break-word; }

.eyebrow,
.page-kicker {
  margin: 0 0 0.9rem;
  color: var(--accent);
  font-size: 0.76rem;
  font-weight: 800;
  letter-spacing: 0.13em;
  text-transform: uppercase;
}

.hero {
  padding: 5rem 0 4.7rem;
  background: linear-gradient(180deg, rgba(230, 240, 246, 0.45), rgba(251, 250, 247, 0));
}
.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 270px;
  align-items: center;
  gap: clamp(2.8rem, 6vw, 5rem);
}
.hero-grid > div { min-width: 0; }
.hero h1 {
  margin: 0;
  font-size: clamp(3.35rem, 7vw, 5.4rem);
  letter-spacing: -0.045em;
}
.hero .role {
  margin: 0.7rem 0 1.25rem;
  color: var(--muted);
  font-family: var(--serif);
  font-size: clamp(1.3rem, 2.25vw, 1.7rem);
}
.lede {
  max-width: 41rem;
  margin: 0;
  color: #3f5060;
  font-size: 1.1rem;
}
.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  margin-top: 1.9rem;
}
.button {
  display: inline-flex;
  min-height: 2.75rem;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  padding: 0.68rem 0.95rem;
  border: 1px solid transparent;
  border-radius: 0.45rem;
  font-weight: 750;
  text-decoration: none;
}
.button.primary { color: #fff; background: var(--accent-deep); }
.button.primary:hover { color: #fff; background: #102b40; }
.button.secondary {
  color: var(--accent-deep);
  border-color: #bcc7d0;
  background: rgba(255, 255, 255, 0.78);
}
.button.secondary:hover { background: var(--surface); }

.portrait-frame {
  width: 270px;
  margin: 0;
  justify-self: end;
}
.portrait-frame img {
  display: block;
  width: 270px;
  height: 270px;
  max-width: none;
  object-fit: cover;
  object-position: center;
  border: 1px solid #cbd3d9;
  border-radius: 1rem;
  box-shadow: var(--shadow);
}
.portrait-caption {
  margin: 0.62rem 0 0;
  color: var(--muted);
  font-size: 0.78rem;
  text-align: left;
}

.math-strip {
  padding: 1.3rem 0;
  border-block: 1px solid rgba(0, 0, 0, 0.18);
  color: #eaf2f7;
  background: var(--accent-deep);
}
.math-strip .container {
  display: grid;
  grid-template-columns: minmax(260px, 0.85fr) minmax(0, 1.15fr);
  align-items: center;
  gap: 2.5rem;
}
.math-strip .formula {
  font-family: var(--serif);
  font-size: clamp(1.08rem, 2.1vw, 1.42rem);
  white-space: nowrap;
}
.math-strip p {
  margin: 0;
  color: #c8d8e4;
  font-size: 0.9rem;
}

.section-head {
  max-width: var(--reading);
  margin-bottom: 2rem;
}
.section-head h2,
.page-hero h1 {
  margin: 0;
  font-size: clamp(2.15rem, 4.5vw, 3.25rem);
  letter-spacing: -0.035em;
}
.section-head p {
  max-width: 42rem;
  margin: 0.55rem 0 0;
  color: var(--muted);
}

.cards {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
}
.card {
  display: flex;
  min-width: 0;
  flex-direction: column;
  padding: 1.4rem;
  border: 1px solid var(--line);
  border-radius: 0.7rem;
  background: var(--surface);
  box-shadow: 0 8px 24px rgba(24, 54, 79, 0.04);
}
.card h3 {
  margin: 0 0 0.58rem;
  font-size: 1.32rem;
}
.card p {
  margin: 0;
  color: var(--muted);
}
.card .meta {
  display: block;
  margin-bottom: 0.6rem;
  color: var(--accent);
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
.card-link {
  margin-top: auto;
  padding-top: 1rem;
  font-weight: 750;
}

.feature {
  display: grid;
  grid-template-columns: minmax(280px, 0.9fr) minmax(0, 1.35fr);
  align-items: center;
  gap: clamp(1.7rem, 4vw, 3rem);
  padding: clamp(1.25rem, 3vw, 2rem);
  border: 1px solid var(--line);
  border-radius: 0.8rem;
  background: var(--surface);
  box-shadow: 0 10px 30px rgba(24, 54, 79, 0.045);
}
.feature > div { min-width: 0; }
.feature-math {
  position: relative;
  display: grid;
  min-height: 230px;
  place-items: center;
  overflow: hidden;
  padding: 1.7rem;
  border-radius: 0.6rem;
  color: #fff;
  background: var(--accent-deep);
}
.feature-math::before,
.feature-math::after {
  position: absolute;
  width: 15rem;
  height: 6.5rem;
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: 50%;
  content: "";
  transform: rotate(-12deg);
}
.feature-math::after {
  width: 11rem;
  height: 4.7rem;
  transform: rotate(18deg);
}
.feature-formula {
  position: relative;
  z-index: 2;
  font-family: var(--serif);
  font-size: clamp(1.1rem, 2.3vw, 1.55rem);
  text-align: center;
}
.feature h3 {
  margin: 0.15rem 0 0.75rem;
  font-size: clamp(1.55rem, 2.7vw, 1.9rem);
}
.feature p { color: var(--muted); }
.feature-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1.25rem;
}

.list-clean {
  margin: 0;
  padding: 0;
  list-style: none;
}
.list-clean li {
  padding: 1rem 0;
  border-bottom: 1px solid var(--line);
}
.list-clean li:first-child { border-top: 1px solid var(--line); }
.item-title {
  color: var(--accent-deep);
  font-family: var(--serif);
  font-size: 1.15rem;
  font-weight: 700;
}
.item-meta {
  margin-top: 0.18rem;
  color: var(--muted);
  font-size: 0.9rem;
}

.page-hero {
  padding: 4.5rem 0 3.5rem;
  background: linear-gradient(180deg, rgba(230, 240, 246, 0.38), rgba(251, 250, 247, 0));
}
.page-hero .container > * { max-width: 46rem; }
.page-hero p:last-child {
  margin: 1rem 0 0;
  color: var(--muted);
  font-size: 1.08rem;
}
.two-col {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
}
.prose h2 {
  margin: 2.6rem 0 0.75rem;
  font-size: 2rem;
}
.prose h2:first-child { margin-top: 0; }
.prose h3 { margin-top: 2rem; }
.prose p,
.prose li { color: #415364; }
.note {
  margin-top: 1.5rem;
  padding: 1.15rem 1.3rem;
  border-left: 4px solid var(--accent);
  border-radius: 0 0.55rem 0.55rem 0;
  background: var(--surface-soft);
}

.timeline {
  position: relative;
  max-width: 780px;
  margin-left: 0.35rem;
  padding-left: 2rem;
}
.timeline::before {
  position: absolute;
  top: 0.35rem;
  bottom: 0.35rem;
  left: 0.35rem;
  width: 1px;
  background: #bac7d0;
  content: "";
}
.timeline-item {
  position: relative;
  margin-bottom: 2rem;
}
.timeline-item:last-child { margin-bottom: 0; }
.timeline-item::before {
  position: absolute;
  top: 0.45rem;
  left: -2rem;
  width: 0.72rem;
  height: 0.72rem;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 0 0.32rem var(--accent-soft);
  content: "";
}
.timeline-item h3 { margin: 0 0 0.3rem; }
.timeline-item p { margin: 0.3rem 0; color: var(--muted); }

.cv-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.55fr) minmax(230px, 0.55fr);
  align-items: start;
  gap: 2rem;
}
.cv-aside {
  position: sticky;
  top: 5.7rem;
  align-self: start;
}
.cv-aside .card + .card { margin-top: 1rem; }
.pdf-frame {
  width: 100%;
  min-height: 850px;
  border: 1px solid var(--line);
  border-radius: 0.65rem;
  background: var(--surface);
}

.site-footer {
  padding: 2.1rem 0;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.9rem;
}
.footer-grid {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
}
.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
}
.footer-links a { color: var(--muted); }

@media (max-width: 860px) {
  .hero-grid,
  .feature,
  .cv-layout { grid-template-columns: 1fr; }

  .hero-grid { gap: 2.7rem; }
  .portrait-frame {
    width: 240px;
    justify-self: start;
  }
  .portrait-frame img {
    width: 240px;
    height: 240px;
  }
  .cards { grid-template-columns: 1fr 1fr; }
  .feature-math { min-height: 205px; }
  .cv-aside { position: static; }
  .math-strip .container {
    grid-template-columns: 1fr;
    gap: 0.4rem;
  }
  .two-col { grid-template-columns: 1fr; }
}

@media (max-width: 650px) {
  .container,
  .narrow,
  .nav-wrap { width: min(100% - 2rem, var(--max)); }

  .menu-button { display: inline-flex; }
  .nav-links {
    position: absolute;
    top: calc(100% + 0.4rem);
    right: 1rem;
    left: 1rem;
    display: none;
    flex-direction: column;
    align-items: stretch;
    padding: 0.6rem;
    border: 1px solid var(--line);
    border-radius: 0.65rem;
    background: rgba(255, 255, 255, 0.99);
    box-shadow: var(--shadow);
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 0.72rem 0.8rem; }

  .hero { padding: 3.7rem 0; }
  .hero h1 { font-size: clamp(3rem, 16vw, 4.25rem); }
  .hero-actions .button { flex: 1 1 10rem; }
  .portrait-frame { width: 220px; }
  .portrait-frame img {
    width: 220px;
    height: 220px;
  }

  .section { padding: 3.7rem 0; }
  .section.compact { padding: 3rem 0; }
  .cards { grid-template-columns: 1fr; }
  .page-hero { padding: 3.7rem 0 3rem; }
  .feature { padding: 1rem; }
  .feature-math { min-height: 185px; }
  .math-strip .formula { white-space: normal; }
  .footer-grid {
    flex-direction: column;
    align-items: flex-start;
  }
  .pdf-frame { min-height: 560px; }
}

@media print {
  .site-header,
  .site-footer,
  .hero-actions,
  .menu-button { display: none; }
  body { background: #fff; }
  .section,
  .page-hero { padding: 1.5rem 0; }
}