:root {
  --bg: #0b0d17;
  --surface: #11182a;
  --surface-alt: #141d33;
  --surface-light: #18233a;
  --border: #1f2a40;
  --text: #f5f7ff;
  --muted: #c3cadc;
  --accent: #5b8def;
  --accent-soft: rgba(91, 141, 239, 0.18);
  --success: #41b883;
  --font-body: 'Inter', 'Segoe UI', Roboto, sans-serif;
  --font-display: 'Playfair Display', 'Times New Roman', serif;
}

* {
  box-sizing: border-box;
}

body {
  font-family: var(--font-body);
  background-color: var(--bg);
  color: var(--text);
  margin: 0;
  padding-top: 84px;
  line-height: 1.7;
}

.sr-only,
.visually-hidden {
  position: absolute !important;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: fixed;
  left: 50%;
  top: 0;
  transform: translate(-50%, -120%);
  padding: 0.75rem 1.5rem;
  border-radius: 999px;
  background: var(--text);
  color: var(--bg);
  font-weight: 600;
  text-decoration: none;
  z-index: 2000;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.skip-link:focus-visible {
  transform: translate(-50%, 1rem);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.45);
  outline: 3px solid var(--accent);
  outline-offset: 4px;
}

@media (prefers-reduced-motion: reduce) {
  .skip-link {
    transition: none;
  }
}

a {
  color: var(--accent);
  transition: color 0.2s ease, opacity 0.2s ease;
}

a:hover,
a:focus-visible {
  color: #86aef7;
  text-decoration: none;
}

a:focus-visible,
button:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 3px;
}

.evidence {
  font-size: 0.92rem;
  color: #a3a3a3;
}

.evidence a {
  margin-right: 0.8rem;
  text-decoration: underline;
}

.navbar {
  background-color: rgba(8, 10, 18, 0.95) !important;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  letter-spacing: 0.02em;
}

.navbar-brand {
  font-family: var(--font-display);
  font-size: 1.6rem;
}

.navbar-nav .nav-link {
  font-weight: 500;
  color: var(--muted) !important;
  padding: 0.75rem 1rem;
}

.navbar-nav .nav-link:hover,
.navbar-nav .nav-link:focus-visible {
  color: var(--text) !important;
}

.nav-item--has-submenu {
  position: relative;
}

.nav-link--toggle {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  border: 0;
  background: transparent;
  color: inherit;
  font: inherit;
  padding-right: 1.5rem;
  cursor: pointer;
}

.nav-link--toggle::after {
  content: '\25be';
  font-size: 0.75em;
  transition: transform 0.2s ease;
}

.nav-link--toggle[aria-expanded="true"]::after {
  transform: rotate(-180deg);
}

.nav-submenu {
  list-style: none;
  margin: 0;
  padding: 0.35rem 0;
  position: absolute;
  top: calc(100% - 0.25rem);
  right: 0.25rem;
  min-width: 220px;
  border-radius: 14px;
  border: 1px solid var(--border);
  background: var(--surface);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.45);
  z-index: 1200;
}

.nav-submenu[hidden] {
  display: none;
}

.nav-submenu li {
  width: 100%;
}

.nav-submenu__link {
  display: block;
  width: 100%;
  padding: 0.55rem 1rem;
  color: var(--muted);
  font-weight: 500;
  text-decoration: none;
}

.nav-submenu__link:hover,
.nav-submenu__link:focus-visible {
  color: var(--text);
  background: var(--surface-alt);
}

@media (max-width: 991.98px) {
  .nav-item--has-submenu {
    width: 100%;
  }

  .nav-item--has-submenu .nav-submenu {
    position: static;
    border: 0;
    box-shadow: none;
    background: transparent;
    padding: 0;
    margin-top: 0.35rem;
  }

  .nav-item--has-submenu .nav-submenu__link {
    padding-left: 0;
    padding-right: 0;
  }
}

main section {
  padding: 96px 0;
}

.section-title {
  font-family: var(--font-display);
  font-size: 2.5rem;
  margin-bottom: 0.75rem;
  letter-spacing: 0.02em;
}

.section-subtitle,
.section-intro {
  max-width: 780px;
  margin: 0 auto 2.5rem auto;
  color: var(--muted);
  font-size: 1.05rem;
}

.hero-layout {
  row-gap: 40px;
}

.landing {
  background: radial-gradient(circle at top left, rgba(91, 141, 239, 0.12), transparent 45%),
              radial-gradient(circle at bottom right, rgba(65, 184, 131, 0.18), transparent 55%),
              linear-gradient(140deg, #090b13 0%, #0f1626 60%, #0b0d17 100%);
  padding: 140px 0 120px;
}

.hero-eyebrow {
  display: inline-block;
  font-size: 0.85rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 18px;
}

.hero-subhead {
  font-size: 1.5rem;
  font-weight: 500;
  color: #f2f4ff;
  margin-bottom: 12px;
}

.hero-name {
  font-size: 1rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 16px;
}

.hero-lede {
  font-size: 1.15rem;
  color: var(--muted);
  margin-top: 18px;
}

.hero-lockup {
  font-size: 0.95rem;
  color: var(--muted);
  margin-top: 16px;
}

.hero-highlights {
  list-style: none;
  padding: 0;
  margin: 28px 0 36px;
}

.hero-highlights li {
  position: relative;
  padding-left: 28px;
  margin-bottom: 14px;
  font-size: 1.02rem;
}

.hero-highlights li::before {
  content: '';
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--accent);
  position: absolute;
  left: 0;
  top: 10px;
  box-shadow: 0 0 0 6px var(--accent-soft);
}

.hero-cta .btn {
  font-weight: 600;
  padding: 14px 30px;
  border-radius: 999px;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.btn-cta {
  background: var(--accent);
  border: 1px solid transparent;
  color: #05060a;
  box-shadow: 0 18px 40px rgba(91, 141, 239, 0.28);
}

.btn-cta:hover,
.btn-cta:focus {
  transform: translateY(-2px);
  background: #779ef5;
}

.btn-outline-light:hover,
.btn-outline-light:focus,
.btn-primary:hover,
.btn-primary:focus {
  transform: translateY(-2px);
  box-shadow: 0 12px 28px rgba(0, 0, 0, 0.35);
}

.hero-figure {
  background: rgba(10, 13, 22, 0.8);
  border: 1px solid var(--border);
  border-radius: 24px;
  padding: 28px;
  text-align: center;
  margin-bottom: 24px;
}

.profile-image {
  width: 100%;
  max-width: 320px;
  height: auto;
  border-radius: 24px;
  border: 4px solid rgba(255, 255, 255, 0.12);
  margin-bottom: 18px;
}

.hero-figure figcaption {
  font-size: 0.95rem;
  color: var(--muted);
}

.hero-meta-grid {
  display: grid;
  gap: 16px;
}

.hero-meta-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 20px 22px;
}

.hero-meta-card h3 {
  font-size: 1.05rem;
  margin-bottom: 6px;
}

.hero-meta-card p {
  color: var(--muted);
  margin-bottom: 0;
}

.about {
  background: #0c121f;
}

.about-grid {
  display: grid;
  gap: 24px;
  margin-top: 48px;
}

.about-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 28px;
  min-height: 100%;
}

.about-card h3 {
  font-size: 1.25rem;
  margin-bottom: 16px;
}

.about-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.about-list li {
  position: relative;
  padding-left: 22px;
  margin-bottom: 12px;
  color: var(--muted);
}

.about-list li::before {
  content: '\2022';
  color: var(--accent);
  position: absolute;
  left: 0;
  top: 0;
}

.capabilities {
  background: linear-gradient(160deg, #0c121f 0%, #0b0d17 60%, #0c111c 100%);
}

.capability-card {
  background: var(--surface-alt);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 28px;
  display: flex;
  flex-direction: column;
}

.capability-card h3 {
  font-size: 1.25rem;
  margin-bottom: 12px;
}

.capability-card p {
  color: var(--muted);
  margin-bottom: 16px;
}

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

.capability-card li {
  color: var(--muted);
  position: relative;
  padding-left: 20px;
  margin-bottom: 10px;
}

.capability-card li::before {
  content: '';
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent);
  position: absolute;
  left: 0;
  top: 12px;
}

.experience {
  background: #0b0f19;
}

.roadmap-timeline {
  display: grid;
  gap: 20px;
  margin-top: 48px;
}

.roadmap-item {
  position: relative;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 24px 28px 24px 40px;
}

.roadmap-item::before {
  content: '';
  position: absolute;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 0 8px var(--accent-soft);
  left: 18px;
  top: 32px;
}

.roadmap-date {
  font-size: 0.85rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--muted);
}

.roadmap-item h3 {
  margin-top: 12px;
  font-size: 1.2rem;
}

.roadmap-item p {
  color: var(--muted);
  margin-bottom: 0;
}

.certifications {
  background: #0f1626;
}

.credential-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 22px;
  padding: 30px;
  height: 100%;
}

.credential-card h3 {
  font-size: 1.2rem;
  margin-bottom: 18px;
}

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

.credential-card li {
  color: var(--muted);
  margin-bottom: 14px;
  padding-left: 20px;
  position: relative;
}

.credential-card li::before {
  content: '\2022';
  position: absolute;
  left: 0;
  top: 0;
  color: var(--accent);
}

.portfolio {
  background: #0c121f;
}

.portfolio .col-md-6 {
  margin-bottom: 28px;
}

.portfolio .row {
  row-gap: 28px;
}

@supports (row-gap: 1px) {
  .portfolio .col-md-6 {
    margin-bottom: 0;
  }
}

.custom-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 22px;
  margin-bottom: 0;
}

.custom-card .card-title {
  font-size: 1.25rem;
  margin-bottom: 12px;
}

.custom-card .card-text {
  color: var(--muted);
}

.project-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 18px 0;
}

.project-meta {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 16px;
}

.project-meta:last-child {
  margin-bottom: 0;
}

.cred-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.cred-badge {
  display: inline-flex;
  align-items: center;
  border-radius: 8px;
  background: rgba(91, 141, 239, 0.12);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  padding: 4px 6px;
}

.cred-badge:focus,
.cred-badge:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(15, 23, 42, 0.25);
}

.cred-badge img {
  height: 18px;
  width: auto;
  display: block;
}

.project-prs {
  margin: 0;
  font-size: 0.85rem;
  color: var(--muted);
}

.project-prs__label {
  font-weight: 600;
  color: var(--text, #e8edf9);
  margin-right: 6px;
}

.project-prs a {
  color: var(--accent);
  font-weight: 600;
  text-decoration: none;
}

.project-prs a:hover,
.project-prs a:focus {
  text-decoration: underline;
}

.project-prs__divider {
  color: var(--muted);
  margin: 0 6px;
}

@media (max-width: 576px) {
  .cred-badge img {
    height: 16px;
  }

  .project-prs {
    line-height: 1.6;
  }
}

.badge-tech {
  background: rgba(91, 141, 239, 0.18);
  color: var(--accent);
  font-weight: 600;
  border-radius: 999px;
  padding: 6px 14px;
  font-size: 0.75rem;
  letter-spacing: 0.05em;
}

.project-details {
  list-style: none;
  padding: 0;
  margin: 0 0 16px;
}

.project-details li {
  color: var(--muted);
  margin-bottom: 10px;
  padding-left: 20px;
  position: relative;
}

.project-details li::before {
  content: '';
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
  position: absolute;
  left: 0;
  top: 11px;
}

.project-links {
  margin-bottom: 14px;
}

.math-lab {
  background: #0b0f19;
}

.math-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 28px;
  height: 100%;
}

.math-card p,
.math-card li {
  color: var(--muted);
}

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

.math-card li {
  margin-bottom: 12px;
  padding-left: 20px;
  position: relative;
}

.math-card li::before {
  content: '\2022';
  position: absolute;
  left: 0;
  top: 0;
  color: var(--accent);
}

.math-lab-footer {
  color: var(--muted);
  margin-top: 28px;
}

.math-lab-footer .math-lab-teaser {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  margin-left: 0.75rem;
  font-size: 0.8rem;
  color: rgba(238, 246, 255, 0.6);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.math-lab-teaser__glyph {
  display: inline-block;
  font-family: 'STIX Two Math', 'STIX Two Text', 'Cambria Math', 'Times New Roman', 'Georgia', serif;
  font-weight: 700;
  font-size: 1rem;
  line-height: 1;
  color: var(--accent);
  text-decoration: none;
  padding: 0.1rem 0.28rem;
  border-radius: 0.35rem;
  transition: color 180ms ease, background-color 180ms ease, transform 180ms ease;
}

.math-lab-teaser__glyph:focus,
.math-lab-teaser__glyph:hover {
  color: #0f1729;
  background-color: var(--accent);
  transform: translateY(-1px);
  text-decoration: none;
}

.contact {
  background: linear-gradient(160deg, #0a0f1b 0%, #0b141f 60%, #09101a 100%);
}

.contact-summary {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 22px;
  padding: 32px;
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.contact-actions {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.contact-btn {
  width: 100%;
}

.contact-response {
  color: var(--muted);
  font-size: 0.95rem;
  margin: 0;
}

.contact-form .form-control {
  background: var(--surface-alt);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 14px;
  padding: 14px 16px;
}

.contact-form .form-control:focus {
  background: var(--surface-light);
  border-color: var(--accent);
  box-shadow: 0 0 0 0.25rem rgba(91, 141, 239, 0.2);
}

.contact-submit {
  width: 100%;
  padding: 14px 28px;
  border-radius: 14px;
}

.contact-form__status {
  margin-top: 0.75rem;
  min-height: 1.5rem;
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--muted);
  transition: color 0.2s ease;
}

.contact-form__status[data-state="success"] {
  color: var(--success);
}

.contact-form__status[data-state="error"] {
  color: #ff6b6b;
}

.social-media-container {
  margin-top: 32px;
}

.social-media-buttons a {
  border-radius: 50% !important;
  width: 46px;
  height: 46px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin: 0 6px;
  transition: transform 0.2s ease;
}

.social-media-buttons a:hover,
.social-media-buttons a:focus {
  transform: translateY(-2px);
}

.proof-block {
  margin-top: 2rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
}

.proof-title {
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 0.75rem;
  color: var(--muted);
}

.proof-list {
  margin: 0;
  padding-left: 1.2rem;
  color: var(--muted);
  font-size: 0.98rem;
}

.proof-list li + li {
  margin-top: 0.75rem;
}

.proof-link {
  color: var(--accent);
  text-decoration: none;
}

.proof-link:hover,
.proof-link:focus {
  text-decoration: underline;
}

@media (min-width: 768px) {
  .about-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (max-width: 991.98px) {
  body {
    padding-top: 74px;
  }

  .landing {
    padding-top: 120px;
  }
}

@media (max-width: 767.98px) {
  main section {
    padding: 72px 0;
  }

  .hero-highlights li {
    font-size: 0.98rem;
  }

  .hero-subhead {
    font-size: 1.25rem;
  }

  .hero-name {
    letter-spacing: 0.12em;
  }

  .hero-meta-grid {
    grid-template-columns: 1fr;
  }

  .contact-actions {
    flex-direction: column;
  }
}

@media (max-width: 575.98px) {
  .hero-figure {
    padding: 24px 18px;
  }

  .profile-image {
    max-width: 260px;
  }
}