:root {
  /* Dark theme (default) */
  --bg: #0A0E1A;
  --surface: #111827;
  --border: #1F2937;
  --text: #F9FAFB;
  --muted: #6B7280;
  --accent: #00D4FF;
  --accent-bg: rgba(0, 212, 255, 0.08);
  --nav-blur: rgba(10, 14, 26, 0.85);
  --card-shadow: 0 4px 24px rgba(0, 0, 0, 0.4);
  --btn-primary-text: #0A0E1A;
  --text-soft: rgba(249, 250, 251, 0.84);
  --text-strong: rgba(249, 250, 251, 0.9);
  --text-faint: rgba(249, 250, 251, 0.74);
  --surface-soft: rgba(17, 24, 39, 0.75);
  --surface-strong: rgba(17, 24, 39, 0.92);
  --surface-elevated: rgba(17, 24, 39, 0.98);
  --surface-banner: rgba(17, 24, 39, 0.9);
  --surface-panel: rgba(8, 12, 22, 0.92);
  --surface-footer: rgba(8, 12, 22, 0.95);
  --nav-link: rgba(249, 250, 251, 0.84);
  --shadow-soft: 0 18px 40px rgba(0, 0, 0, 0.28);
  --shadow-menu: 0 18px 48px rgba(0, 0, 0, 0.35);
  --accent-border: rgba(0, 212, 255, 0.2);
  --accent-border-strong: rgba(0, 212, 255, 0.35);
  --accent-glow: rgba(0, 212, 255, 0.18);
  --accent-glow-strong: rgba(0, 212, 255, 0.35);
  --accent-fill-soft: rgba(0, 212, 255, 0.1);
  --accent-fill-mid: rgba(0, 212, 255, 0.12);
  --accent-fill-strong: rgba(0, 212, 255, 0.16);
  --accent-line-soft: rgba(0, 212, 255, 0.12);
  --accent-line-mid: rgba(0, 212, 255, 0.18);
  --accent-line-strong: rgba(0, 212, 255, 0.8);
  --accent-line-focus: rgba(0, 212, 255, 0.6);
  --accent-ring: rgba(0, 212, 255, 0.12);
  --accent-bg-strong: rgba(0, 212, 255, 0.08);
  --border-strong: rgba(31, 41, 55, 0.9);
  --border-soft: rgba(249, 250, 251, 0.08);
  --border-faint: rgba(249, 250, 251, 0.06);
  --disabled-bg: rgba(107, 114, 128, 0.12);
  --disabled-border: rgba(107, 114, 128, 0.28);
  --tech-bg: rgba(249, 250, 251, 0.03);
  --input-shadow: 0 0 0 3px rgba(0, 212, 255, 0.12);
  --radius: 8px;
  --transition: 0.3s ease;
  --max-width: 1100px;
  --header-height: 76px;
}

[data-theme="light"] {
  --bg: #F5F7FA;
  --surface: #FFFFFF;
  --border: #E2E8F0;
  --text: #0F172A;
  --muted: #64748B;
  --accent: #0284C7;
  --accent-bg: #DBEAFE;
  --nav-blur: rgba(245, 247, 250, 0.90);
  --card-shadow: 0 4px 24px rgba(0, 0, 0, 0.08);
  --btn-primary-text: #FFFFFF;
  --text-soft: rgba(15, 23, 42, 0.82);
  --text-strong: rgba(15, 23, 42, 0.9);
  --text-faint: rgba(15, 23, 42, 0.68);
  --surface-soft: rgba(255, 255, 255, 0.88);
  --surface-strong: rgba(255, 255, 255, 0.96);
  --surface-elevated: rgba(255, 255, 255, 0.98);
  --surface-banner: rgba(255, 255, 255, 0.96);
  --surface-panel: rgba(255, 255, 255, 0.94);
  --surface-footer: rgba(255, 255, 255, 0.98);
  --nav-link: rgba(15, 23, 42, 0.78);
  --shadow-soft: 0 18px 40px rgba(15, 23, 42, 0.08);
  --shadow-menu: 0 18px 48px rgba(15, 23, 42, 0.12);
  --accent-border: rgba(2, 132, 199, 0.2);
  --accent-border-strong: rgba(2, 132, 199, 0.35);
  --accent-glow: rgba(2, 132, 199, 0.18);
  --accent-glow-strong: rgba(2, 132, 199, 0.24);
  --accent-fill-soft: rgba(2, 132, 199, 0.08);
  --accent-fill-mid: rgba(2, 132, 199, 0.12);
  --accent-fill-strong: rgba(2, 132, 199, 0.16);
  --accent-line-soft: rgba(2, 132, 199, 0.12);
  --accent-line-mid: rgba(2, 132, 199, 0.18);
  --accent-line-strong: rgba(2, 132, 199, 0.78);
  --accent-line-focus: rgba(2, 132, 199, 0.6);
  --accent-ring: rgba(2, 132, 199, 0.12);
  --accent-bg-strong: rgba(2, 132, 199, 0.08);
  --border-strong: rgba(226, 232, 240, 0.95);
  --border-soft: rgba(15, 23, 42, 0.08);
  --border-faint: rgba(15, 23, 42, 0.06);
  --disabled-bg: rgba(100, 116, 139, 0.12);
  --disabled-border: rgba(100, 116, 139, 0.28);
  --tech-bg: rgba(15, 23, 42, 0.04);
  --input-shadow: 0 0 0 3px rgba(2, 132, 199, 0.12);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body,
body * {
  transition: background-color 0.3s ease, color 0.3s ease,
              border-color 0.3s ease, box-shadow 0.3s ease;
}

body {
  margin: 0;
  font-family: "Inter", sans-serif;
  background:
    radial-gradient(circle at top left, var(--accent-bg), transparent 28%),
    radial-gradient(circle at top right, var(--accent-fill-soft), transparent 22%),
    linear-gradient(180deg, var(--bg) 0%, var(--bg) 45%, var(--bg) 100%);
  color: var(--text);
  line-height: 1.6;
}

img {
  max-width: 100%;
}

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

button,
input,
textarea {
  font: inherit;
}

.container {
  width: min(calc(100% - 2rem), var(--max-width));
  margin: 0 auto;
}

.section {
  padding: 4.5rem 0;
}

.page-main {
  padding-top: var(--header-height);
}

.page-hero {
  padding: 3.5rem 0 1rem;
}

.section-tag,
.eyebrow {
  margin: 0 0 0.85rem;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  font-size: 0.78rem;
  font-weight: 700;
}

.page-subtitle {
  max-width: 720px;
  color: var(--text-soft);
  font-size: 1.05rem;
}

.section-heading {
  margin-bottom: 2rem;
}

.section-heading h2,
.page-hero h1,
.hero-copy h1 {
  margin: 0;
  line-height: 1.1;
}

.section-heading h2,
.page-hero h1 {
  font-size: clamp(2rem, 4vw, 3rem);
}

.site-header,
.nav {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--nav-blur);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-strong);
}

.nav-wrapper {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: var(--header-height);
  gap: 1rem;
}

.logo {
  font-family: "Courier New", monospace;
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: 0.1em;
}

.theme-toggle {
  background: transparent;
  border: 0.5px solid var(--border);
  border-radius: 50%;
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--muted);
  transition: all 0.3s ease;
  flex-shrink: 0;
  margin-left: auto;
}

.theme-toggle:hover {
  color: var(--accent);
  border-color: var(--accent);
  background: var(--accent-bg);
}

.site-nav {
  position: absolute;
  top: calc(100% + 0.75rem);
  left: 1rem;
  right: 1rem;
  display: none;
  flex-direction: column;
  padding: 1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface-elevated);
  box-shadow: var(--shadow-menu);
}

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

.nav-link,
.site-nav a {
  position: relative;
  color: var(--muted);
  text-decoration: none;
  font-size: 0.95rem;
  padding: 4px 0;
  transition: color 0.3s ease;
}

.nav-link::after,
.site-nav a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 100%;
  height: 2px;
  background: var(--accent);
  border-radius: 2px;
  transform: scaleX(0);
  transition: transform 0.25s ease;
}

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

.nav-link:hover::after,
.site-nav a:hover::after {
  transform: scaleX(1);
}

.nav-link.active,
.site-nav a.active {
  color: var(--accent);
  font-weight: 500;
}

.nav-link.active::after,
.site-nav a.active::after {
  transform: scaleX(1);
}

.nav-toggle {
  display: inline-flex;
  flex-direction: column;
  justify-content: center;
  gap: 0.3rem;
  width: 46px;
  height: 46px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: transparent;
  color: var(--text);
  cursor: pointer;
}

.nav-toggle span {
  width: 20px;
  height: 2px;
  margin: 0 auto;
  background: currentColor;
  transition: transform var(--transition), opacity var(--transition);
}

.nav-toggle.is-open span:nth-child(1) {
  transform: translateY(6px) rotate(45deg);
}

.nav-toggle.is-open span:nth-child(2) {
  opacity: 0;
}

.nav-toggle.is-open span:nth-child(3) {
  transform: translateY(-6px) rotate(-45deg);
}

.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: calc(var(--header-height) + 2rem) 0 4rem;
}

.hero-grid,
.two-column,
.contact-layout,
.meta-grid {
  display: grid;
  gap: 1.5rem;
}

.hero-copy h1 {
  font-size: clamp(2.75rem, 8vw, 4.75rem);
}

.hero-copy h2 {
  margin: 0.75rem 0 1.25rem;
  color: var(--accent);
  font-size: clamp(1.3rem, 3vw, 2rem);
}

.hero-text {
  max-width: 640px;
  color: var(--text-strong);
  font-size: 1.05rem;
}

.hero-actions,
.project-actions,
.social-links,
.badge-row,
.tech-badges,
.timeline-tags,
.featured-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0.8rem 1.2rem;
  border-radius: var(--radius);
  border: 1px solid transparent;
  font-weight: 600;
  cursor: pointer;
  transition: transform var(--transition), box-shadow var(--transition), background var(--transition), border-color var(--transition), color var(--transition);
}

.button:hover,
.panel:hover,
.role-card:hover,
.stat-card:hover,
.project-card:hover,
.timeline-card:hover,
.cert-card:hover,
.contact-card:hover,
.skills-column:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-soft);
}

.button-primary {
  background: var(--accent);
  color: var(--btn-primary-text);
  box-shadow: 0 0 0 transparent;
}

.button-primary:hover {
  box-shadow: 0 0 24px var(--accent-glow);
}

.button-secondary {
  background: transparent;
  color: var(--text);
  border-color: var(--accent-border-strong);
}

.button-pill {
  min-height: 40px;
  padding: 0.6rem 0.9rem;
  background: transparent;
  color: var(--text-strong);
  border-color: var(--accent-border);
  font-size: 0.92rem;
}

.button-block {
  width: 100%;
}

.button-disabled {
  background: var(--disabled-bg);
  color: var(--muted);
  border-color: var(--disabled-border);
  cursor: not-allowed;
  box-shadow: none;
}

.button-disabled:hover {
  transform: none;
  box-shadow: none;
}

.stats-grid,
.roles-grid,
.project-list,
.cert-grid {
  display: grid;
  gap: 1rem;
}

.stat-card,
.panel,
.role-card,
.project-card,
.timeline-card,
.cert-card,
.contact-card,
.skills-column,
.contact-form {
  background: var(--surface-strong);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.stat-card {
  padding: 1.5rem;
  position: relative;
  overflow: hidden;
}

.stat-card::before {
  content: "";
  position: absolute;
  inset: auto -25% 0 auto;
  width: 90px;
  height: 90px;
  background: radial-gradient(circle, var(--accent-fill-strong), transparent 65%);
}

.stat-card strong {
  display: block;
  font-size: 2rem;
  color: var(--accent);
}

.stat-card span {
  color: var(--text-strong);
}

.resume-dropdown {
  margin-top: 1rem;
  width: fit-content;
}

.resume-toggle {
  gap: 0.55rem;
}

.resume-caret {
  font-size: 0.8rem;
  transition: transform var(--transition);
}

.resume-dropdown.is-open .resume-caret {
  transform: rotate(180deg);
}

.resume-menu {
  min-width: 260px;
  display: grid;
  gap: 0.35rem;
  padding: 0.65rem;
  margin-top: 0.75rem;
  background: var(--surface-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-menu);
}

.resume-menu[hidden] {
  display: none !important;
}

.resume-option {
  display: block;
  padding: 0.8rem 0.9rem;
  border-radius: calc(var(--radius) - 2px);
  color: var(--text-strong);
  transition: background var(--transition), color var(--transition), transform var(--transition);
}

.resume-option:hover {
  background: var(--accent-bg);
  color: var(--accent);
  transform: translateX(2px);
}

[data-theme="light"] .resume-menu {
  box-shadow: var(--card-shadow);
}

.featured-strip {
  padding: 0 0 1.5rem;
}

.featured-banner {
  display: grid;
  gap: 1.25rem;
  padding: 1.5rem;
  background: var(--surface-banner);
  border: 1px solid var(--border);
  border-left: 4px solid var(--accent);
  border-radius: var(--radius);
}

.featured-banner h2 {
  margin: 0 0 0.75rem;
  font-size: clamp(1.5rem, 2.8vw, 2rem);
}

.featured-banner p:last-child {
  margin-bottom: 0;
  color: var(--text-strong);
}

.badge-strip {
  padding: 1.25rem 0;
  background: var(--surface-soft);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.badge,
.badge-pill,
.year-pill,
.tech-badges span,
.timeline-tags span,
.skills-label {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.45rem 0.8rem;
  border-radius: 999px;
  font-size: 0.88rem;
}

.badge,
.badge-pill,
.year-pill,
.skills-label {
  background: var(--accent-fill-mid);
  color: var(--accent);
  border: 1px solid var(--accent-border);
}

.panel,
.role-card,
.cert-card,
.contact-card,
.skills-column {
  padding: 1.5rem;
}

.panel h3,
.role-card h3,
.cert-card h3,
.skills-column h2,
.skill-group h3,
.contact-card h2 {
  margin-top: 0;
}

.panel p,
.role-card p,
.cert-card p,
.skill-group p,
.contact-card p,
.project-card p,
.project-highlights li,
.timeline-card li {
  color: var(--text-strong);
}

.role-icon {
  display: inline-flex;
  width: 48px;
  height: 48px;
  align-items: center;
  justify-content: center;
  margin-bottom: 0.8rem;
  border-radius: 14px;
  background: var(--accent-fill-soft);
  font-size: 1.25rem;
}

.project-card {
  padding: 1.75rem;
  border-top: 3px solid var(--accent);
}

.project-header {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.project-title-group {
  display: grid;
  gap: 0.85rem;
}

.project-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
}

.project-header h2,
.timeline-card h2 {
  margin: 0;
  font-size: 1.35rem;
}

.project-highlights,
.timeline-card ul {
  padding-left: 1.1rem;
  margin: 1rem 0 1.25rem;
}

.tech-badges span {
  background: var(--tech-bg);
  border: 1px solid var(--border-soft);
  color: var(--text-strong);
}

.diagram-panel {
  margin-top: 1rem;
  padding: 1rem;
  background: var(--surface-panel);
  border: 1px solid var(--accent-border);
  border-radius: var(--radius);
}

.diagram-panel pre {
  margin: 0;
  overflow-x: auto;
  color: var(--text-strong);
  font-family: "Courier New", monospace;
  font-size: 0.92rem;
}

.experience-banner {
  padding: 1.25rem 1.5rem;
  border: 1px solid var(--accent-line-mid);
  border-radius: var(--radius);
  background: linear-gradient(135deg, var(--surface-strong), var(--accent-bg));
  color: var(--text);
}

.timeline {
  position: relative;
  display: grid;
  gap: 1.5rem;
}

.timeline::before,
.timeline-line {
  content: "";
  position: absolute;
  left: 0.75rem;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(180deg, var(--accent-line-strong), var(--accent-line-soft));
}

.timeline-item {
  position: relative;
  padding-left: 2.5rem;
}

.timeline-marker {
  position: absolute;
  left: 0.2rem;
  top: 1.1rem;
  width: 18px;
  height: 18px;
  border: 3px solid var(--bg);
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 18px var(--accent-glow-strong);
}

.timeline-card {
  padding: 1.5rem;
}

.timeline-date {
  margin: 0.4rem 0 0.9rem;
  color: var(--accent);
  font-weight: 600;
}

.skills-split {
  display: grid;
  gap: 1.5rem;
}

.skills-header {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin-bottom: 1.25rem;
}

.skill-group + .skill-group {
  margin-top: 1.25rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--border-faint);
}

.skills-divider {
  display: none;
}

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

.contact-form {
  display: grid;
  gap: 0.8rem;
  padding: 1.5rem;
}

.contact-form label {
  font-weight: 600;
}

.contact-form input,
.contact-form textarea {
  width: 100%;
  padding: 0.9rem 1rem;
  color: var(--text);
  background: var(--surface-panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: border-color var(--transition), box-shadow var(--transition);
}

.contact-form input:focus,
.contact-form textarea:focus {
  outline: none;
  border-color: var(--accent-line-focus);
  box-shadow: var(--input-shadow);
}

.form-note,
.form-success {
  margin: 0.35rem 0 0;
  color: var(--text-strong);
}

.form-success {
  color: var(--accent);
}

.site-footer {
  border-top: 1px solid var(--border);
  padding: 1.5rem 0 2rem;
  background: var(--surface-footer);
}

.footer-inner {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.site-footer p,
.social-links a {
  color: var(--text-faint);
}

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

.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

@media (min-width: 768px) {
  .container {
    width: min(calc(100% - 3rem), var(--max-width));
  }

  .nav-toggle {
    display: none;
  }

  .theme-toggle {
    order: 2;
    margin-left: auto;
  }

  .site-nav {
    position: static;
    display: flex;
    flex-direction: row;
    align-items: center;
    gap: 1.5rem;
    padding: 0;
    border: 0;
    background: transparent;
    box-shadow: none;
    order: 3;
    left: auto;
    right: auto;
    top: auto;
  }

  .nav-link,
  .site-nav a {
    padding: 4px 0;
  }

  .nav-link.active::after,
  .site-nav a.active::after {
    bottom: -0.45rem;
  }

  .hero-grid,
  .two-column,
  .contact-layout,
  .meta-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    align-items: start;
  }

  .stats-grid,
  .roles-grid,
  .cert-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .footer-inner {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }

  .featured-banner {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
  }

  .featured-actions {
    justify-content: flex-end;
  }
}

@media (max-width: 768px) {
  .nav-link::after,
  .site-nav a::after {
    display: none;
  }

  .nav-link.active,
  .site-nav a.active {
    color: var(--accent);
    padding-left: 10px;
    border-left: 3px solid var(--accent);
  }

  .nav-link:hover,
  .site-nav a:hover {
    padding-left: 10px;
    border-left: 3px solid var(--border);
  }
}

@media (min-width: 1024px) {
  .hero-grid {
    grid-template-columns: minmax(0, 1.2fr) minmax(360px, 0.8fr);
    gap: 2rem;
  }

  .roles-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .project-list,
  .cert-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .project-card:first-child {
    grid-column: span 2;
  }

  .experience-banner {
    grid-column: span 2;
  }

  .skills-split {
    grid-template-columns: minmax(0, 1fr) 90px minmax(0, 1fr);
    align-items: stretch;
  }

  .skills-divider {
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
  }

  .skills-divider::before {
    content: "";
    position: absolute;
    top: 0;
    bottom: 0;
    width: 2px;
    background: linear-gradient(180deg, var(--accent-line-strong), var(--accent-line-soft));
  }

  .skills-divider span {
    position: relative;
    z-index: 1;
    padding: 0.6rem 0.8rem;
    border: 1px solid var(--accent-border);
    border-radius: 999px;
    background: var(--nav-blur);
    color: var(--accent);
    writing-mode: vertical-rl;
    transform: rotate(180deg);
    text-transform: uppercase;
    letter-spacing: 0.12em;
    font-size: 0.78rem;
    font-weight: 700;
  }
}

[data-theme="light"] .nav {
  background: var(--nav-blur);
  box-shadow: 0 1px 0 var(--border);
}

[data-theme="light"] .stat-card {
  box-shadow: var(--card-shadow);
}

[data-theme="light"] .project-card {
  box-shadow: var(--card-shadow);
}

[data-theme="light"] .cert-card {
  box-shadow: var(--card-shadow);
}

[data-theme="light"] .badge,
[data-theme="light"] .badge-pill {
  background: var(--accent-bg);
  color: var(--accent);
}

[data-theme="light"] .timeline-line,
[data-theme="light"] .timeline::before {
  background: var(--border);
}

[data-theme="light"] .skills-divider span {
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--muted);
}