:root {
  --bg: #101113;
  --panel: #17191d;
  --panel-2: #202329;
  --line: #30343b;
  --text: #f7f7f2;
  --muted: #a6adb8;
  --accent: #ffb400;
  --accent-dark: #d89200;
  --shadow: 0 28px 80px rgba(0, 0, 0, 0.32);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background:
    radial-gradient(circle at top right, rgba(255, 180, 0, 0.08), transparent 30rem),
    var(--bg);
  color: var(--text);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.6;
}

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

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

button,
input,
textarea {
  font: inherit;
}

.section {
  width: min(1130px, calc(100% - 40px));
  margin: 0 auto;
  padding: 88px 0;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 76px;
  padding: 18px clamp(20px, 5vw, 70px);
  background: rgba(16, 17, 19, 0.86);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  backdrop-filter: blur(16px);
}

.brand {
  color: var(--text);
  font-size: 1.45rem;
  font-weight: 900;
  letter-spacing: 0;
}

.brand span {
  color: var(--accent);
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 28px;
  color: var(--muted);
  font-size: 0.94rem;
  font-weight: 800;
}

.site-nav a {
  transition: color 160ms ease;
}

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

.nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  padding: 0;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
}

.nav-toggle span {
  display: block;
  width: 18px;
  height: 2px;
  margin: 5px auto;
  background: var(--text);
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(340px, 0.78fr);
  gap: clamp(34px, 7vw, 90px);
  align-items: center;
  min-height: calc(100vh - 76px);
  padding-top: 58px;
}

.section-kicker {
  margin: 0 0 12px;
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 900;
  letter-spacing: 0;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  max-width: 720px;
  margin-bottom: 24px;
  font-size: clamp(2.1rem, 4.7vw, 4.1rem);
  line-height: 1.05;
  letter-spacing: 0;
}

h2 {
  max-width: 790px;
  margin-bottom: 18px;
  font-size: clamp(2rem, 4vw, 3.35rem);
  line-height: 1.08;
  letter-spacing: 0;
}

h3 {
  margin-bottom: 10px;
  font-size: 1.22rem;
  line-height: 1.25;
}

.hero-content > p:not(.section-kicker),
.section-copy > p:not(.section-kicker),
.work-card p,
.publication-card p,
.credential-grid p {
  color: var(--muted);
}

.hero-content > p:not(.section-kicker) {
  max-width: 650px;
  margin-bottom: 30px;
  font-size: 1.08rem;
}

.hero-actions,
.button-row {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  align-items: center;
}

.quick-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 16px;
}

.quick-links a {
  display: inline-flex;
  align-items: center;
  min-height: 36px;
  padding: 0 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.035);
  color: var(--muted);
  font-size: 0.88rem;
  font-weight: 850;
}

.quick-links a:hover {
  color: var(--accent);
  border-color: rgba(255, 180, 0, 0.5);
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 20px;
  border: 1px solid transparent;
  border-radius: 8px;
  font-weight: 900;
  transition: transform 160ms ease, border-color 160ms ease, background 160ms ease;
}

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

.button-primary {
  background: var(--accent);
  color: #17120a;
}

.button-primary:hover {
  background: var(--accent-dark);
}

.button-ghost {
  border-color: var(--line);
  background: rgba(255, 255, 255, 0.03);
  color: var(--text);
}

.social-row {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  margin-top: 32px;
  color: var(--muted);
  font-size: 0.9rem;
  font-weight: 800;
}

.social-row a:hover,
.contact-list a:hover,
.credential-grid a:hover {
  color: var(--accent);
}

.hero-visual {
  position: relative;
}

.portrait-card {
  position: relative;
  overflow: hidden;
  min-height: 600px;
  border-radius: 8px;
  background:
    linear-gradient(155deg, rgba(255, 180, 0, 0.22), transparent 48%),
    var(--panel);
  box-shadow: var(--shadow);
}

.portrait-card::before {
  content: "";
  position: absolute;
  inset: 12% 9% auto auto;
  width: 74%;
  aspect-ratio: 1;
  border-radius: 50%;
  background: var(--accent);
  opacity: 0.9;
}

.portrait-card img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center top;
  filter: saturate(1.04);
}

.floating-card {
  position: absolute;
  right: -22px;
  bottom: 32px;
  display: flex;
  align-items: center;
  gap: 12px;
  width: min(280px, 80%);
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(23, 25, 29, 0.94);
  box-shadow: var(--shadow);
  font-weight: 900;
}

.floating-card img {
  width: 58px;
  height: 58px;
  border-radius: 50%;
  background: #fff;
}

.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  padding-top: 0;
}

.stats article {
  min-height: 130px;
  padding: 24px;
  background: var(--panel);
  border: 1px solid var(--line);
}

.stats strong {
  display: block;
  color: var(--accent);
  font-size: clamp(2.1rem, 4vw, 3.4rem);
  line-height: 1;
}

.stats span {
  color: var(--muted);
  font-weight: 800;
}

.about {
  display: grid;
  grid-template-columns: minmax(280px, 0.78fr) minmax(0, 1fr);
  gap: clamp(34px, 7vw, 82px);
  align-items: center;
}

.about-image {
  overflow: hidden;
  border-radius: 8px;
  background: #fff;
  box-shadow: var(--shadow);
}

.about-image img {
  width: 100%;
  aspect-ratio: 4 / 5;
  object-fit: cover;
  object-position: center;
}

.section-copy p {
  max-width: 720px;
}

.centered {
  max-width: 820px;
  margin: 0 auto 26px;
  text-align: center;
}

.centered h2 {
  max-width: 760px;
  margin-right: auto;
  margin-left: auto;
}

.centered p {
  margin-right: auto;
  margin-left: auto;
}

.skill-tabs {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin: 30px 0 24px;
}

.tab-button {
  min-width: 104px;
  min-height: 42px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  color: var(--muted);
  font-weight: 900;
  cursor: pointer;
}

.tab-button.is-active {
  background: var(--accent);
  color: #17120a;
  border-color: var(--accent);
}

.skill-panel,
.paper-tags {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
}

.skill-panel[hidden] {
  display: none;
}

.logo-card,
.paper-tags span {
  display: grid;
  min-height: 58px;
  place-items: center;
  padding: 10px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  color: var(--text);
  font-weight: 850;
  text-align: center;
}

.logo-card {
  min-height: 124px;
  gap: 10px;
  align-content: center;
}

.icon-box {
  display: grid;
  width: 52px;
  height: 52px;
  place-items: center;
  border-radius: 8px;
  background: #fff;
}

.icon-box img {
  width: 31px;
  height: 31px;
  object-fit: contain;
}

.text-logo {
  color: #17120a;
  font-size: 1.35rem;
  font-weight: 950;
}

.logo-card strong {
  display: block;
  font-size: 0.92rem;
  line-height: 1.2;
}

.work,
.services,
.publication,
.certifications,
.contact {
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.service-grid,
.work-grid,
.credential-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
  margin-top: 34px;
}

.service-grid article,
.work-card,
.credential-grid article,
.publication-card,
.contact-form {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  box-shadow: 0 18px 45px rgba(0, 0, 0, 0.18);
}

.service-grid article {
  min-height: 230px;
  padding: 24px;
}

.service-grid span {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  margin-bottom: 22px;
  border-radius: 8px;
  background: var(--accent);
  color: #17120a;
  font-weight: 950;
}

.service-grid p {
  color: var(--muted);
}

.work-card {
  overflow: hidden;
}

.work-card img {
  width: 100%;
  height: 245px;
  object-fit: cover;
  background: #fff;
}

.work-card div {
  padding: 22px;
}

.work-card span,
.paper-meta {
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 900;
  text-transform: uppercase;
}

.publication-card {
  padding: clamp(22px, 4vw, 34px);
}

.publication-card h3 {
  max-width: 930px;
  font-size: clamp(1.45rem, 3vw, 2.35rem);
}

.publication-card .citation,
.publication-card .doi {
  color: var(--text);
  font-weight: 800;
}

.paper-tags {
  grid-template-columns: repeat(6, minmax(0, 1fr));
  margin: 24px 0;
}

.paper-tags span {
  min-height: 42px;
  background: var(--panel-2);
  font-size: 0.86rem;
}

.credential-grid article {
  min-height: 250px;
  padding: 24px;
}

.credential-grid img {
  width: 84px;
  height: 84px;
  margin-bottom: 18px;
  border-radius: 50%;
  background: #fff;
}

.credential-grid a {
  color: var(--accent);
  font-weight: 900;
}

.contact {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(320px, 1fr);
  gap: clamp(28px, 6vw, 70px);
}

.contact-list {
  display: grid;
  gap: 10px;
  margin-top: 24px;
}

.contact-list a {
  color: var(--muted);
  font-weight: 850;
  overflow-wrap: anywhere;
}

.contact-form {
  display: grid;
  gap: 16px;
  padding: 24px;
}

.contact-form label {
  display: grid;
  gap: 7px;
}

.contact-form span {
  color: var(--muted);
  font-size: 0.9rem;
  font-weight: 850;
}

.contact-form input,
.contact-form textarea {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel-2);
  color: var(--text);
  padding: 13px 14px;
  outline: none;
}

.contact-form input:focus,
.contact-form textarea:focus {
  border-color: var(--accent);
}

.contact-form textarea {
  resize: vertical;
}

.footer {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  padding: 28px clamp(20px, 5vw, 70px);
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  color: var(--muted);
}

.footer p {
  margin: 0;
}

@media (max-width: 940px) {
  .nav-toggle {
    display: block;
  }

  .site-nav {
    position: absolute;
    top: 76px;
    right: 20px;
    left: 20px;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 8px;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: var(--panel);
    box-shadow: var(--shadow);
  }

  .site-nav.is-open {
    display: flex;
  }

  .site-nav a {
    padding: 12px;
  }

  .hero,
  .about,
  .contact {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
  }

  .portrait-card {
    min-height: 520px;
  }

  .stats,
  .service-grid,
  .work-grid,
  .credential-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .skill-panel {
    grid-template-columns: repeat(3, 1fr);
  }

  .paper-tags {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (max-width: 620px) {
  .section {
    width: min(100% - 28px, 1130px);
    padding: 64px 0;
  }

  .site-header {
    padding-inline: 14px;
  }

  h1 {
    font-size: 3.3rem;
  }

  h2 {
    font-size: 2.25rem;
  }

  .portrait-card {
    min-height: 430px;
  }

  .floating-card {
    right: 12px;
    bottom: 12px;
  }

  .stats,
  .service-grid,
  .work-grid,
  .credential-grid,
  .skill-panel,
  .paper-tags {
    grid-template-columns: 1fr;
  }

  .work-card img {
    height: 220px;
  }

  .footer {
    flex-direction: column;
  }
}