:root {
  --color-primary-dark: #0f172a;
  --color-primary: #1e3a8a;
  --color-accent: #3b82f6;
  --color-cyan: #06b6d4;
  --color-success: #10b981;
  --color-warning: #f59e0b;
  --color-slate: #0b1224;
  --color-slate-light: #1f2937;
  --color-text: #e2e8f0;
  --color-muted: #94a3b8;
  --color-white: #ffffff;
  --shadow-lg: 0 20px 50px rgba(2, 6, 23, 0.55);

  --font-sans: "Segoe UI", "Inter", system-ui, -apple-system, sans-serif;
  --font-mono: "SFMono-Regular", "Consolas", "Liberation Mono", monospace;

  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 24px;

  --space-xs: 0.5rem;
  --space-sm: 0.75rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;

  --max-width: 1200px;
  --header-height: 72px;
  --transition: 0.3s ease;
}

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

html {
  scroll-behavior: auto;
  font-size: 16px;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  background: radial-gradient(circle at top, rgba(30, 58, 138, 0.35), transparent 50%),
    var(--color-primary-dark);
  color: var(--color-text);
  line-height: 1.6;
}

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

a:focus-visible,
button:focus-visible {
  outline: 2px solid var(--color-cyan);
  outline-offset: 3px;
}

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

ul,
ol {
  padding: 0;
  margin: 0;
  list-style: none;
}

button {
  font-family: inherit;
}

.skip-link {
  position: absolute;
  left: -999px;
  top: 0;
  padding: var(--space-sm) var(--space-md);
  background: var(--color-cyan);
  color: var(--color-primary-dark);
  z-index: 1000;
}

.skip-link:focus {
  left: var(--space-md);
  top: var(--space-md);
}

.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(15, 23, 42, 0.85);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(148, 163, 184, 0.12);
}

.nav {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--space-lg);
  height: var(--header-height);
}

.nav__brand {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-weight: 600;
}

.nav__logo {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--color-accent), var(--color-cyan));
  display: grid;
  place-items: center;
  color: var(--color-white);
  font-weight: 700;
}

.nav__menu {
  display: flex;
  gap: var(--space-lg);
}

.nav__link {
  font-size: 0.95rem;
  color: var(--color-muted);
  transition: color var(--transition);
}

.nav__link:hover,
.nav__link.is-active {
  color: var(--color-white);
}

.nav__toggle {
  display: none;
  flex-direction: column;
  gap: 6px;
  background: transparent;
  border: none;
  cursor: pointer;
}

.nav__toggle-bar {
  width: 24px;
  height: 2px;
  background: var(--color-white);
}

.lang-toggle {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  border-radius: 999px;
  border: 1px solid rgba(148, 163, 184, 0.3);
  background: rgba(30, 58, 138, 0.2);
  color: var(--color-white);
  cursor: pointer;
}

.section {
  padding: var(--space-3xl) var(--space-lg);
  max-width: var(--max-width);
  margin: 0 auto;
}

.section__header {
  margin-bottom: var(--space-2xl);
}

.section__eyebrow {
  text-transform: uppercase;
  letter-spacing: 2px;
  color: var(--color-cyan);
  font-size: 0.75rem;
  margin-bottom: var(--space-sm);
}

.section__title {
  font-size: clamp(1.8rem, 2.5vw, 2.6rem);
  margin: 0;
}

.card {
  background: rgba(30, 41, 59, 0.5);
  border: 1px solid rgba(148, 163, 184, 0.18);
  border-radius: var(--radius-md);
  padding: var(--space-xl);
  box-shadow: var(--shadow-lg);
  backdrop-filter: blur(16px);
  transition: transform var(--transition), box-shadow var(--transition), border var(--transition);
}

.card:hover {
  transform: translateY(-6px);
  border-color: rgba(59, 130, 246, 0.5);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.6rem;
  border-radius: 999px;
  border: none;
  font-weight: 600;
  cursor: pointer;
  transition: transform var(--transition), box-shadow var(--transition), background var(--transition);
}

.btn--primary {
  background: linear-gradient(135deg, var(--color-accent), var(--color-cyan));
  color: var(--color-white);
  box-shadow: 0 12px 30px rgba(59, 130, 246, 0.35);
}

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

.btn--secondary {
  background: transparent;
  color: var(--color-white);
  border: 1px solid rgba(148, 163, 184, 0.4);
}

.btn--ghost {
  background: rgba(148, 163, 184, 0.1);
  color: var(--color-white);
  border: 1px solid rgba(148, 163, 184, 0.2);
}

.hero {
  position: relative;
  padding-top: calc(var(--space-3xl) + var(--header-height));
  min-height: 90vh;
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at top left, rgba(59, 130, 246, 0.4), transparent 55%),
    radial-gradient(circle at 20% 40%, rgba(6, 182, 212, 0.35), transparent 45%),
    linear-gradient(120deg, rgba(30, 58, 138, 0.25), transparent 50%);
  z-index: -1;
}

.hero__content {
  display: grid;
  gap: var(--space-2xl);
  align-items: center;
}

.hero__image {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  align-items: flex-start;
}

.hero__image img {
  border-radius: 50%;
  border: 4px solid rgba(59, 130, 246, 0.5);
  box-shadow: 0 20px 40px rgba(15, 23, 42, 0.7);
}

.hero__status {
  background: rgba(16, 185, 129, 0.12);
  color: var(--color-success);
  padding: 4px 12px;
  border-radius: 999px;
  font-size: 0.85rem;
}

.hero__title {
  font-size: clamp(2.2rem, 4vw, 3.5rem);
  margin: 0 0 var(--space-sm);
  background: linear-gradient(90deg, var(--color-white), var(--color-cyan));
  -webkit-background-clip: text;
  color: transparent;
}

.hero__subtitle {
  font-size: 1.2rem;
  color: var(--color-muted);
  margin-bottom: var(--space-sm);
}

.hero__location {
  color: var(--color-cyan);
  margin-bottom: var(--space-md);
}

.hero__tagline {
  font-size: 1.05rem;
  max-width: 560px;
  min-height: 72px;
}

.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
  margin: var(--space-lg) 0;
}

.hero__social {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
}

.social-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: 8px 12px;
  border-radius: 999px;
  background: rgba(148, 163, 184, 0.08);
  transition: background var(--transition), transform var(--transition);
}

.social-link:hover {
  transform: translateY(-2px);
  background: rgba(59, 130, 246, 0.2);
}

.about__grid {
  display: grid;
  gap: var(--space-lg);
}

.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
}

.tag {
  background: rgba(59, 130, 246, 0.2);
  color: var(--color-white);
  padding: 6px 12px;
  border-radius: 999px;
  font-size: 0.85rem;
}

.values li {
  display: grid;
  gap: 6px;
  margin-bottom: var(--space-md);
}

.timeline {
  display: grid;
  gap: var(--space-lg);
  position: relative;
}

.timeline::before {
  content: "";
  position: absolute;
  left: 24px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(var(--color-accent), var(--color-cyan));
  opacity: 0.6;
}

.timeline__item {
  padding-left: var(--space-3xl);
  position: relative;
}

.timeline__item::before {
  content: "";
  position: absolute;
  left: 14px;
  top: 24px;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--color-cyan);
  box-shadow: 0 0 0 6px rgba(6, 182, 212, 0.2);
}

.timeline__header {
  display: grid;
  gap: 4px;
  margin-bottom: var(--space-sm);
}

.timeline__date {
  color: var(--color-muted);
  font-size: 0.9rem;
}

.timeline__list li {
  margin-bottom: var(--space-sm);
}

.skills__grid {
  display: grid;
  gap: var(--space-lg);
}

.skill {
  margin-bottom: var(--space-md);
}

.skill__name {
  font-size: 0.9rem;
  color: var(--color-muted);
}

.skill-bar {
  height: 8px;
  border-radius: 999px;
  background: rgba(148, 163, 184, 0.2);
  overflow: hidden;
  margin-top: var(--space-xs);
}

.skill-bar__fill {
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--color-accent), var(--color-cyan));
  border-radius: 999px;
  transition: width 1s ease-out;
}

.education__grid {
  display: grid;
  gap: var(--space-lg);
}

.education__certs {
  display: grid;
  gap: var(--space-md);
}

.achievements__grid,
.projects__grid {
  display: grid;
  gap: var(--space-lg);
}

.achievement__metric {
  font-size: 1.6rem;
  color: var(--color-cyan);
  font-weight: 700;
}

.project {
  display: grid;
  gap: var(--space-lg);
}

.project__image img {
  border-radius: var(--radius-md);
}

.project__features li {
  margin-bottom: var(--space-sm);
}

.project__links {
  display: flex;
  gap: var(--space-md);
  margin-top: var(--space-md);
}

.project__links a {
  color: var(--color-cyan);
  font-weight: 600;
}

.contact__grid {
  display: grid;
  gap: var(--space-lg);
}

.contact__details {
  display: grid;
  gap: var(--space-lg);
}

.contact__item span {
  color: var(--color-muted);
  display: block;
  margin-bottom: 6px;
}

.footer {
  margin-top: var(--space-2xl);
  text-align: center;
  color: var(--color-muted);
}

.back-to-top {
  position: fixed;
  right: var(--space-lg);
  bottom: var(--space-lg);
  width: 44px;
  height: 44px;
  border-radius: 50%;
  border: none;
  background: rgba(59, 130, 246, 0.9);
  color: var(--color-white);
  display: grid;
  place-items: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition), transform var(--transition);
  z-index: 50;
}

.back-to-top.is-visible {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(-6px);
}

.toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  background: rgba(15, 23, 42, 0.95);
  padding: 10px 18px;
  border-radius: 999px;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition);
  color: var(--color-white);
  border: 1px solid rgba(59, 130, 246, 0.4);
}

.toast.is-visible {
  opacity: 1;
}

.section.is-visible,
.card.is-visible {
  animation: fadeInUp 0.6s ease-out both;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 900px) {
  .nav__menu {
    position: fixed;
    inset: var(--header-height) 0 auto 0;
    background: rgba(15, 23, 42, 0.98);
    flex-direction: column;
    padding: var(--space-lg);
    gap: var(--space-md);
    transform: translateY(-120%);
    transition: transform var(--transition);
  }

  .nav__menu.is-open {
    transform: translateY(0);
  }

  .nav__toggle {
    display: flex;
  }
}

@media (min-width: 768px) {
  .hero__content {
    grid-template-columns: 1fr 1.2fr;
  }

  .about__grid,
  .education__grid,
  .contact__grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .skills__grid,
  .achievements__grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .projects__grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .project {
    grid-template-rows: auto 1fr;
  }
}

@media (min-width: 1024px) {
  .skills__grid {
    grid-template-columns: repeat(4, 1fr);
  }

  .projects__grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

@media (min-width: 1440px) {
  .hero__content {
    grid-template-columns: 1fr 1.4fr;
  }

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

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

@media print {
  body {
    background: #ffffff;
    color: #111827;
  }

  .header,
  .back-to-top,
  .toast,
  .hero__actions,
  .hero__social,
  .contact__actions {
    display: none !important;
  }

  .card {
    box-shadow: none;
    border-color: #e5e7eb;
    background: #ffffff;
  }

  .section {
    padding: 1.5rem 0;
  }
}