:root {
  --bg: #fafafa;
  --bg-alt: #f0f0f2;
  --surface: #ffffff;
  --text: #1a1a1a;
  --text-secondary: #4a4a4a;
  --text-muted: #6b6b6b;
  --accent: #2c5282;
  --accent-hover: #1a365d;
  --border: #e2e2e6;
  --focus: #3182ce;

  --font-sans: "Inter", system-ui, -apple-system, sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, monospace;

  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4.5rem;

  --container: 72rem;
  --radius: 6px;
  --header-h: 4rem;
}

@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;
  }
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--accent); text-decoration-thickness: 1px; text-underline-offset: 2px; }
a:hover { color: var(--accent-hover); }
:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 2px;
}

.skip-link {
  position: absolute;
  top: -100%;
  left: var(--space-md);
  background: var(--accent);
  color: #fff;
  padding: var(--space-sm) var(--space-md);
  z-index: 1000;
  border-radius: var(--radius);
}
.skip-link:focus { top: var(--space-md); }

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

.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(250, 250, 250, 0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}
.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-h);
  gap: var(--space-lg);
}
.logo {
  display: flex;
  flex-direction: column;
  text-decoration: none;
  color: inherit;
  line-height: 1.2;
}
.logo__name {
  font-weight: 600;
  font-size: 1rem;
}
.logo__role {
  font-size: 0.75rem;
  color: var(--text-muted);
}
.nav__list {
  display: flex;
  gap: var(--space-lg);
  list-style: none;
  margin: 0;
  padding: 0;
}
.nav__list a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
}
.nav__list a:hover,
.nav__list a:focus-visible { color: var(--accent); }

.header__actions {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.lang-switcher {
  display: flex;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}
.lang-btn {
  background: transparent;
  border: none;
  padding: 0.35rem 0.6rem;
  font-size: 0.75rem;
  font-weight: 600;
  font-family: inherit;
  color: var(--text-muted);
  cursor: pointer;
}
.lang-btn:hover { background: var(--bg-alt); }
.lang-btn.active {
  background: var(--accent);
  color: #fff;
}

.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  padding: 0.4rem;
  cursor: pointer;
}
.menu-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text);
}
.nav-mobile {
  display: none;
  border-top: 1px solid var(--border);
  background: var(--bg);
}
.nav-mobile ul {
  list-style: none;
  margin: 0;
  padding: var(--space-md);
}
.nav-mobile a {
  display: block;
  padding: var(--space-sm) 0;
  color: var(--text);
  text-decoration: none;
  font-weight: 500;
}

.hero {
  padding: var(--space-3xl) 0 var(--space-2xl);
}
.hero__label {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--accent);
  margin: 0 0 var(--space-sm);
  letter-spacing: 0.02em;
}
.hero__title {
  font-size: clamp(1.8rem, 5vw, 2.6rem);
  font-weight: 700;
  line-height: 1.15;
  margin: 0 0 var(--space-md);
  letter-spacing: -0.02em;
}
.hero__desc {
  max-width: 38rem;
  color: var(--text-secondary);
  margin: 0 0 var(--space-xl);
  font-size: 1.05rem;
}
.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.7rem 1.25rem;
  font-size: 0.95rem;
  font-weight: 500;
  font-family: inherit;
  border-radius: var(--radius);
  border: 1px solid transparent;
  cursor: pointer;
  text-decoration: none;
  transition: background 0.15s, color 0.15s, border-color 0.15s;
}
.btn--primary {
  background: var(--accent);
  color: #fff;
}
.btn--primary:hover {
  background: var(--accent-hover);
  color: #fff;
}
.btn--secondary {
  background: transparent;
  color: var(--text);
  border-color: var(--border);
}
.btn--secondary:hover {
  border-color: var(--text-muted);
  background: var(--bg-alt);
}

.section {
  padding: var(--space-3xl) 0;
}
.section--alt {
  background: var(--bg-alt);
}
.section__title {
  font-size: 1.5rem;
  font-weight: 700;
  margin: 0 0 var(--space-lg);
  letter-spacing: -0.01em;
}
.section__intro {
  color: var(--text-secondary);
  max-width: 40rem;
  margin: -0.5rem 0 var(--space-xl);
}

.about__grid {
  display: grid;
  gap: var(--space-xl);
}
@media (min-width: 768px) {
  .about__grid {
    grid-template-columns: 1.6fr 1fr;
    align-items: start;
  }
}
.about__text p {
  margin: 0 0 var(--space-md);
  color: var(--text-secondary);
}
.info-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: var(--space-md) var(--space-lg);
  margin-bottom: var(--space-md);
}
.info-card h3 {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-muted);
  margin: 0 0 var(--space-sm);
}
.info-card p, .info-card ul {
  margin: 0;
  font-size: 0.95rem;
}
.info-card ul {
  list-style: none;
  padding: 0;
}
.info-card li { padding: 0.15rem 0; }

.skills-grid {
  display: grid;
  gap: var(--space-xl);
}
@media (min-width: 640px) {
  .skills-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}
@media (min-width: 960px) {
  .skills-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}
.skill-group h3 {
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-muted);
  margin: 0 0 var(--space-sm);
}
.skill-group--highlight h3 {
  color: var(--accent);
}
.tags {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}
.tags li {
  font-size: 0.875rem;
  padding: 0.3rem 0.65rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 999px;
  color: var(--text);
}

.projects-list {
  display: grid;
  gap: var(--space-lg);
}
.project-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: var(--space-lg);
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}
.project-card__header {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-sm);
}
.project-card__title {
  font-size: 1.15rem;
  font-weight: 600;
  margin: 0;
}
.project-card__stack {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--accent);
}
.project-card__desc {
  margin: 0;
  color: var(--text-secondary);
  font-size: 0.95rem;
}
.project-card__links {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
  margin-top: var(--space-sm);
}
.project-card__links a {
  font-size: 0.875rem;
  font-weight: 500;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
}
.project-card__links a::after {
  content: "→";
  font-size: 0.9em;
}

.education__item,
.experience__item {
  margin-bottom: var(--space-xl);
}
.education__item:last-child,
.experience__item:last-child {
  margin-bottom: 0;
}
.education__item h3,
.experience__item h3 {
  font-size: 1.1rem;
  margin: 0 0 0.2rem;
}
.education__school {
  font-weight: 500;
  margin: 0;
}
.education__meta,
.experience__meta {
  font-size: 0.875rem;
  color: var(--text-muted);
  margin: 0 0 var(--space-sm);
}
.education__topics,
.experience__item ul {
  margin: 0;
  padding-left: 1.2rem;
  color: var(--text-secondary);
}
.education__topics li,
.experience__item li {
  margin-bottom: 0.25rem;
}

.contact-grid {
  display: grid;
  gap: var(--space-lg);
  margin-bottom: var(--space-xl);
}
@media (min-width: 640px) {
  .contact-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}
.contact-item {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}
.contact-label {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-muted);
  font-weight: 600;
}
.contact-item a {
  font-weight: 500;
  text-decoration: none;
}
.contact-item a:hover {
  text-decoration: underline;
}
.contact__resume {
  margin-top: var(--space-md);
}

.footer {
  padding: var(--space-xl) 0;
  border-top: 1px solid var(--border);
  text-align: center;
  font-size: 0.875rem;
  color: var(--text-muted);
}
.footer p { margin: 0.3rem 0; }
.footer__links a {
  color: var(--text-muted);
  text-decoration: none;
}
.footer__links a:hover { color: var(--accent); }

.back-to-top {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  width: 2.75rem;
  height: 2.75rem;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  font-size: 1.1rem;
  cursor: pointer;
  box-shadow: 0 2px 8px rgba(0,0,0,0.08);
  z-index: 50;
  display: grid;
  place-items: center;
}
.back-to-top:hover {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}

/* ========== RESPONSIVE ========== */
@media (max-width: 768px) {
  .nav { display: none; }
  .menu-toggle { display: flex; }
  .nav-mobile:not([hidden]) { display: block; }
  .hero { padding-top: var(--space-2xl); }
  .section { padding: var(--space-2xl) 0; }
}

@media (max-width: 480px) {
  .hero__actions { flex-direction: column; align-items: stretch; }
  .btn { width: 100%; }
     }