:root {
  --bg: #f7f8fb;
  --surface: #ffffff;
  --surface-soft: #eef3f7;
  --text: #17202a;
  --muted: #5d6a78;
  --line: #d8e0e8;
  --accent: #1769aa;
  --accent-strong: #0f4f83;
  --accent-soft: #e8f3fb;
  --shadow: 0 18px 45px rgba(23, 32, 42, 0.10);
  --radius: 8px;
  --max: 1180px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Arial, sans-serif;
  font-size: 17px;
  line-height: 1.68;
}

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

a {
  color: var(--accent-strong);
  text-decoration-thickness: 0.08em;
  text-underline-offset: 0.16em;
}

a:hover {
  color: var(--accent);
}

:focus-visible {
  outline: 3px solid color-mix(in srgb, var(--accent) 70%, white);
  outline-offset: 4px;
}

.skip-link {
  position: absolute;
  left: 1rem;
  top: 1rem;
  z-index: 10;
  transform: translateY(-140%);
  background: var(--text);
  color: #fff;
  padding: 0.65rem 0.9rem;
  border-radius: var(--radius);
}

.skip-link:focus {
  transform: translateY(0);
}

.site-header {
  border-bottom: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(14px);
  position: sticky;
  top: 0;
  z-index: 3;
}

.nav {
  max-width: var(--max);
  margin: 0 auto;
  padding: 1rem 1.2rem;
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  align-items: center;
}

.brand {
  color: var(--text);
  font-weight: 800;
  letter-spacing: 0;
  text-decoration: none;
}

.nav-links {
  display: flex;
  gap: 0.4rem;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.nav-links a {
  border-radius: 999px;
  color: var(--muted);
  font-size: 0.98rem;
  padding: 0.5rem 0.78rem;
  text-decoration: none;
}

.nav-links a:hover {
  background: var(--accent-soft);
  color: var(--accent-strong);
}

.hero {
  overflow: hidden;
  position: relative;
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    linear-gradient(135deg, color-mix(in srgb, var(--accent-soft) 70%, transparent), transparent 56%),
    radial-gradient(circle at 86% 12%, color-mix(in srgb, var(--accent) 14%, transparent), transparent 30%);
  pointer-events: none;
}

.hero-inner {
  max-width: var(--max);
  margin: 0 auto;
  padding: clamp(3.8rem, 8vw, 6.8rem) 1.2rem;
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(280px, 0.78fr);
  gap: clamp(2rem, 5vw, 4.5rem);
  align-items: center;
}

.eyebrow {
  color: var(--accent-strong);
  font-size: 0.82rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  margin: 0 0 0.85rem;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  overflow-wrap: anywhere;
}

h1 {
  font-size: clamp(2.4rem, 5vw, 4.8rem);
  letter-spacing: 0;
  line-height: 1.02;
  margin: 0;
}

.role {
  color: var(--accent-strong);
  font-size: clamp(1.05rem, 2vw, 1.35rem);
  font-weight: 760;
  margin: 1rem 0 0;
}

.tagline {
  color: var(--muted);
  font-size: clamp(1.02rem, 1.8vw, 1.25rem);
  max-width: 65ch;
  margin: 1.1rem 0 0;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1.55rem;
}

.button,
.button-secondary {
  border-radius: 999px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0.72rem 1rem;
  text-decoration: none;
  font-weight: 750;
}

.button {
  background: var(--accent);
  color: #fff;
}

.button:hover {
  background: var(--accent-strong);
  color: #fff;
}

.button-secondary {
  background: var(--surface);
  border: 1px solid var(--line);
  color: var(--text);
}

.photo-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 0.85rem;
}

.photo-card img {
  aspect-ratio: var(--photo-ratio, 4 / 5);
  border-radius: calc(var(--radius) - 2px);
  object-fit: cover;
  object-position: var(--photo-position, center);
  width: 100%;
}

.stats {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0.8rem;
  margin-top: 1.8rem;
}

.stat {
  background: rgba(255, 255, 255, 0.78);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1rem;
}

.stat strong {
  display: block;
  font-size: 1.2rem;
}

.stat span {
  color: var(--muted);
  font-size: 0.95rem;
}

main {
  background: var(--surface);
}

.section {
  border-top: 1px solid var(--line);
  padding: clamp(3.2rem, 6vw, 5.4rem) 1.2rem;
}

.section-inner {
  max-width: var(--max);
  margin: 0 auto;
}

.section-heading {
  display: grid;
  grid-template-columns: minmax(220px, 0.44fr) minmax(0, 1fr);
  gap: clamp(1rem, 4vw, 3rem);
  margin-bottom: 1.8rem;
}

h2 {
  font-size: clamp(1.7rem, 3vw, 2.5rem);
  line-height: 1.1;
  margin: 0;
}

.lead {
  color: var(--muted);
  font-size: 1.1rem;
  line-height: 1.68;
  margin: 0;
}

.content-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1.15rem;
}

.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.3rem;
}

.card h3 {
  font-size: 1.1rem;
  line-height: 1.25;
  margin: 0 0 0.45rem;
}

.card p,
.timeline p,
.credential p {
  color: var(--muted);
  font-size: 1rem;
  margin: 0;
}

.summary {
  display: grid;
  gap: 1.15rem;
  max-width: 82ch;
}

.summary p {
  margin: 0;
}

.timeline {
  display: grid;
  gap: 1.15rem;
}

.timeline article {
  border-left: 4px solid var(--accent);
  background: var(--surface);
  border-radius: 0 var(--radius) var(--radius) 0;
  padding: 1.25rem 1.3rem 1.25rem 1.4rem;
}

.timeline h3,
.credential h3 {
  margin: 0 0 0.25rem;
}

.meta {
  color: var(--accent-strong);
  font-size: 0.92rem;
  font-weight: 750;
  margin: 0 0 0.45rem;
}

.credentials {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1.15rem;
}

.note {
  background: var(--accent-soft);
  border: 1px solid color-mix(in srgb, var(--accent) 18%, var(--line));
  border-radius: var(--radius);
  color: var(--text);
  font-size: 1rem;
  line-height: 1.65;
  padding: 1.2rem 1.3rem;
}

.contact-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  list-style: none;
  margin: 1rem 0 0;
  padding: 0;
}

.contact-list a {
  background: var(--surface-soft);
  border-radius: 999px;
  display: inline-flex;
  font-size: 0.98rem;
  padding: 0.68rem 0.95rem;
  text-decoration: none;
}

.site-footer {
  background: #111922;
  color: #d9e2ec;
  padding: 2.6rem 1.2rem;
}

.site-footer .section-inner {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.site-footer a {
  color: #ffffff;
}

.theme-growth {
  --accent: #157f5b;
  --accent-strong: #0b6044;
  --accent-soft: #e8f7f1;
}

.theme-product {
  --accent: #245fc7;
  --accent-strong: #173f8c;
  --accent-soft: #eaf0ff;
}

.theme-physics {
  --accent: #6f4cc3;
  --accent-strong: #51349a;
  --accent-soft: #f0ecff;
}

.theme-math {
  --accent: #9b3f6e;
  --accent-strong: #742a50;
  --accent-soft: #faedf4;
}

.layout-split .content-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.layout-research .hero-inner {
  grid-template-columns: minmax(0, 0.9fr) minmax(300px, 0.66fr);
}

.layout-elegant .photo-card {
  border-top: 4px solid var(--accent);
}

.preview-page {
  min-height: 100vh;
  background: linear-gradient(135deg, #f7f8fb, #eef4f9);
}

.preview {
  max-width: 960px;
  margin: 0 auto;
  padding: clamp(3rem, 8vw, 6rem) 1.2rem;
}

.preview h1 {
  max-width: 12ch;
}

.preview-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
  margin-top: 2rem;
}

@media (max-width: 860px) {
  .hero-inner,
  .section-heading,
  .layout-research .hero-inner {
    grid-template-columns: 1fr;
  }

  .content-grid,
  .layout-split .content-grid,
  .credentials,
  .stats,
  .preview-grid {
    grid-template-columns: 1fr;
  }

  .nav {
    align-items: flex-start;
    flex-direction: column;
  }

  .nav-links {
    justify-content: flex-start;
  }

  .photo-card {
    max-width: 460px;
  }

  .hero-inner {
    padding-top: 3rem;
  }

  .tagline,
  .lead {
    font-size: 1.05rem;
  }
}