:root {
  color-scheme: dark;
  --bg-primary: #0b0b0b;
  --bg-secondary: #111111;
  --surface: #171717;
  --surface-2: #1f1f1f;
  --text-primary: #ffffff;
  --text-secondary: #a1a1aa;
  --line: rgba(255, 255, 255, 0.12);
  --line-soft: rgba(255, 255, 255, 0.08);
  --focus-ring: #f5f5f5;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: "Inter", sans-serif;
  background:
    radial-gradient(70rem 45rem at 10% -10%, rgba(255, 255, 255, 0.06), transparent 40%),
    radial-gradient(60rem 40rem at 90% 10%, rgba(255, 255, 255, 0.03), transparent 45%),
    linear-gradient(180deg, var(--bg-secondary), var(--bg-primary));
  color: var(--text-primary);
  line-height: 1.65;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

img { display: block; width: 100%; }
a { color: inherit; }
.container-xl { max-width: 1200px; }

.scroll-progress {
  position: fixed;
  inset: 0 auto auto 0;
  width: 100%;
  height: 2px;
  z-index: 1200;
}

.scroll-progress span {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, #f5f5f5, #868686);
  transition: width 0.08s linear;
}

.site-rail {
  position: fixed;
  inset: 0 auto 0 0;
  width: 84px;
  padding: 1.2rem 0.75rem;
  border-right: 1px solid var(--line-soft);
  background: rgba(11, 11, 11, 0.92);
  backdrop-filter: blur(14px);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  z-index: 1100;
}

.rail-brand {
  width: 42px;
  height: 42px;
  margin: 0 auto;
  display: grid;
  place-items: center;
  border: 1px solid var(--line);
  border-radius: 50%;
  text-decoration: none;
  font-weight: 800;
  letter-spacing: 0.08em;
  font-size: 0.88rem;
}

.rail-nav {
  display: grid;
  gap: 0.45rem;
  margin-top: 1.25rem;
}

.rail-link {
  width: 42px;
  height: 42px;
  margin: 0 auto;
  border-radius: 0.8rem;
  display: grid;
  place-items: center;
  color: var(--text-secondary);
  text-decoration: none;
  border: 1px solid transparent;
  --nav-shift-x: 0px;
  --nav-shift-y: 0px;
  transition: transform 280ms cubic-bezier(0.22, 1, 0.36, 1), color 200ms ease, border-color 200ms ease, background-color 200ms ease;
  position: relative;
}

.rail-link i { font-size: 1.05rem; }

.rail-link::after {
  content: attr(data-label);
  position: absolute;
  left: calc(100% + 10px);
  top: 50%;
  transform: translateY(-50%);
  padding: 0.26rem 0.45rem;
  border-radius: 0.4rem;
  background: rgba(14, 14, 14, 0.96);
  border: 1px solid var(--line-soft);
  color: #e9e9e9;
  font-size: 0.72rem;
  white-space: nowrap;
  opacity: 0;
  pointer-events: none;
}

.rail-link:hover::after,
.rail-link.is-active::after { opacity: 1; }

.rail-link:hover,
.rail-link.is-active {
  color: var(--text-primary);
  background: rgba(255, 255, 255, 0.05);
  border-color: rgba(255, 255, 255, 0.09);
  transform: translate3d(var(--nav-shift-x), var(--nav-shift-y), 0);
}

.rail-link:nth-child(4n + 1) { --nav-shift-x: -3px; --nav-shift-y: -2px; }
.rail-link:nth-child(4n + 2) { --nav-shift-x: 3px; --nav-shift-y: -2px; }
.rail-link:nth-child(4n + 3) { --nav-shift-x: -3px; --nav-shift-y: 2px; }
.rail-link:nth-child(4n + 4) { --nav-shift-x: 3px; --nav-shift-y: 2px; }

.rail-note {
  margin: 0;
  padding-top: 0.9rem;
  border-top: 1px solid var(--line-soft);
  color: var(--text-secondary);
  font-size: 0.7rem;
  text-align: center;
  line-height: 1.35;
}

.mobile-nav { position: sticky; top: 0; z-index: 1110; }
.mobile-navbar {
  background: rgba(11, 11, 11, 0.9);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--line-soft);
}
.nav-brand { font-weight: 700; letter-spacing: 0.08em; color: var(--text-primary); }
.nav-toggle { border: 1px solid var(--line); }
.nav-toggle .navbar-toggler-icon { filter: invert(1); }
.mobile-collapse {
  background: rgba(11, 11, 11, 0.98);
  border-bottom: 1px solid var(--line-soft);
}
.mobile-collapse .nav-link { color: var(--text-secondary); font-weight: 500; padding: 0.65rem 0.2rem; }
.mobile-collapse .nav-link {
  transition: transform 260ms cubic-bezier(0.22, 1, 0.36, 1), color 200ms ease;
}
.mobile-collapse .nav-link[aria-current="true"],
.mobile-collapse .nav-link:hover { color: var(--text-primary); }
.mobile-collapse .nav-item:nth-child(odd) .nav-link:hover,
.mobile-collapse .nav-item:nth-child(odd) .nav-link[aria-current="true"] {
  transform: translate3d(-4px, -1px, 0);
}
.mobile-collapse .nav-item:nth-child(even) .nav-link:hover,
.mobile-collapse .nav-item:nth-child(even) .nav-link[aria-current="true"] {
  transform: translate3d(4px, 1px, 0);
}

main { margin-left: 84px; }

.hero {
  position: relative;
  isolation: isolate;
}

.hero-glow {
  position: absolute;
  width: min(52rem, 82vw);
  height: min(52rem, 82vw);
  border-radius: 50%;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  background: radial-gradient(circle, rgba(255, 255, 255, 0.09), rgba(255, 255, 255, 0) 65%);
  filter: blur(8px);
  z-index: -1;
}

.hero-content { max-width: 1200px; width: 100%; padding-top: 4.2rem; }
.hero-label,
.section-kicker {
  margin: 0 0 1rem;
  color: var(--text-secondary);
  font-size: 0.78rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.hero-title {
  margin: 0;
  font-size: clamp(2.5rem, 8vw, 4.4rem);
  line-height: 1.05;
  letter-spacing: -0.03em;
  font-weight: 800;
  max-width: 12ch;
}

.hero-positioning { margin: 1.4rem 0 1rem; font-size: clamp(1.2rem, 2.5vw, 1.55rem); color: #f3f3f3; max-width: 58ch; }
.hero-body { margin: 0; max-width: 64ch; color: var(--text-secondary); font-size: 1.06rem; }
.hero-actions { margin-top: 2rem; display: flex; flex-wrap: wrap; gap: 0.85rem; }

.btn-premium {
  border-radius: 999px;
  border-width: 1px;
  font-weight: 600;
  padding: 0.72rem 1.2rem;
  transition: transform 160ms ease, box-shadow 160ms ease, background-color 180ms ease;
}

.btn-premium:hover { transform: translateY(-2px) scale(1.02); box-shadow: 0 10px 24px rgba(0, 0, 0, 0.35); }
.btn-primary.btn-premium { background: #f3f3f3; color: #111111; border-color: #f3f3f3; }

.section-block { padding: 5.6rem 0; }
.section-title { margin: 0; font-size: clamp(2rem, 6vw, 3rem); line-height: 1.1; letter-spacing: -0.02em; max-width: 22ch; }
.about-copy { margin-top: 1.5rem; max-width: 65ch; color: var(--text-secondary); font-size: 1.05rem; }
.about-copy p { margin: 0 0 1rem; }
.portrait-wrap { border-radius: 1.2rem; overflow: hidden; border: 1px solid var(--line); background: var(--surface); }
.portrait-image { aspect-ratio: 4 / 5; object-fit: cover; }

.section-skills { background: linear-gradient(180deg, rgba(255, 255, 255, 0.02), transparent); }
.skill-card {
  border: 1px solid var(--line-soft);
  border-radius: 1rem;
  padding: 0.95rem;
  color: #ffffff;
  min-height: 100%;
  transition: transform 320ms cubic-bezier(0.22, 1, 0.36, 1), border-color 220ms ease, box-shadow 220ms ease;
}

.skill-card:hover {
  transform: translate3d(0, -4px, 0);
  box-shadow: 0 14px 24px rgba(0, 0, 0, 0.2);
}

.skill-card h3 {
  margin: 0 0 0.65rem;
  font-size: 1rem;
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
}

.skill-card h3 i {
  font-size: 0.95rem;
  width: 1.25rem;
  text-align: center;
}

.skill-chip-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.42rem;
}

.skill-chip-list span {
  display: inline-flex;
  align-items: center;
  border: 1px solid rgba(255, 255, 255, 0.2);
  background: rgba(0, 0, 0, 0.25);
  color: #f5f5f5;
  border-radius: 999px;
  padding: 0.22rem 0.5rem;
  font-size: 0.76rem;
  line-height: 1.25;
}

.skill-blue { background: linear-gradient(145deg, rgba(0, 102, 255, 0.28), rgba(0, 36, 94, 0.45)); border-color: rgba(77, 151, 255, 0.4); }
.skill-yellow { background: linear-gradient(145deg, rgba(248, 207, 63, 0.24), rgba(121, 83, 0, 0.42)); border-color: rgba(240, 190, 37, 0.5); }
.skill-pink { background: linear-gradient(145deg, rgba(236, 72, 153, 0.25), rgba(127, 29, 90, 0.42)); border-color: rgba(236, 72, 153, 0.45); }
.skill-green { background: linear-gradient(145deg, rgba(22, 163, 74, 0.25), rgba(21, 94, 48, 0.42)); border-color: rgba(34, 197, 94, 0.45); }

.section-work { background: linear-gradient(180deg, rgba(255, 255, 255, 0.02), transparent); }
.projects-carousel {
  margin-top: 1.6rem;
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 0.8rem;
  align-items: center;
}

.carousel-btn {
  width: 2.3rem;
  height: 2.3rem;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: rgba(18, 18, 18, 0.85);
  color: #f3f3f3;
  display: grid;
  place-items: center;
  transition: transform 150ms ease, border-color 150ms ease, background-color 150ms ease;
}

.carousel-btn:hover {
  transform: translateY(-1px);
  border-color: rgba(255, 255, 255, 0.3);
  background: rgba(38, 38, 38, 0.9);
}

.project-track {
  display: flex;
  gap: 0.9rem;
  overflow-x: auto;
  padding: 0.2rem;
  scroll-snap-type: x mandatory;
  scrollbar-width: none;
}

.project-track::-webkit-scrollbar {
  display: none;
}

.project-card {
  margin-top: 0;
  border: 1px solid var(--line);
  border-radius: 1rem;
  background: rgba(23, 23, 23, 0.78);
  padding: 1rem;
  transform: translate3d(0, 0, 0);
  transition: transform 340ms cubic-bezier(0.22, 1, 0.36, 1), border-color 220ms ease, box-shadow 220ms ease;
}

.project-card.compact {
  flex: 0 0 min(360px, 82vw);
  scroll-snap-align: start;
}

.project-card:hover { transform: translateY(-3px); border-color: rgba(255, 255, 255, 0.2); box-shadow: 0 20px 36px rgba(0, 0, 0, 0.28); }
.project-card h3 { margin: 0; font-size: 1.08rem; }
.project-description { margin: 0.72rem 0 0.82rem; color: var(--text-secondary); font-size: 0.92rem; }
.project-tech-list, .cert-tech-list { display: flex; flex-wrap: wrap; gap: 0.5rem; margin: 0.9rem 0 0; }
.project-tech-list span, .cert-tech-list span {
  display: inline-flex;
  align-items: center;
  border: 1px solid rgba(255, 255, 255, 0.1);
  background: rgba(255, 255, 255, 0.04);
  color: #f1f1f1;
  border-radius: 999px;
  padding: 0.32rem 0.65rem;
  font-size: 0.82rem;
}
.project-impact {
  margin: 0.85rem 0 0;
  color: #d9d9d9;
  font-size: 0.88rem;
}

.project-impact span {
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-size: 0.74rem;
  margin-right: 0.4rem;
}

.project-actions {
  margin-top: 0.95rem;
}

.github-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.42rem 0.7rem;
  border-radius: 999px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  background: rgba(255, 255, 255, 0.04);
  color: #f6f6f6;
  text-decoration: none;
  font-size: 0.82rem;
  font-weight: 600;
}

.github-btn:hover {
  border-color: rgba(255, 255, 255, 0.35);
  background: rgba(255, 255, 255, 0.08);
}

.project-link { display: inline-block; margin-top: 1rem; color: #f3f3f3; font-weight: 600; text-decoration: none; border-bottom: 1px solid rgba(255, 255, 255, 0.45); }
.project-link:hover { border-bottom-color: #ffffff; }

.section-surface { background: linear-gradient(180deg, rgba(23, 23, 23, 0.72), rgba(23, 23, 23, 0.35)); border-top: 1px solid var(--line-soft); border-bottom: 1px solid var(--line-soft); }

.cert-carousel {
  margin-top: 1.4rem;
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 0.8rem;
  align-items: center;
}

.cert-track {
  display: flex;
  gap: 0.9rem;
  overflow-x: auto;
  padding: 0.2rem;
  scroll-snap-type: x mandatory;
  scrollbar-width: none;
}

.cert-track::-webkit-scrollbar {
  display: none;
}

.cert-card {
  border: 1px solid var(--line-soft);
  background: rgba(22, 22, 22, 0.75);
  border-radius: 1rem;
  padding: 0.95rem;
  display: block;
  transform: translate3d(0, 0, 0);
  transition: transform 320ms cubic-bezier(0.22, 1, 0.36, 1), border-color 220ms ease, box-shadow 220ms ease;
}

.cert-card:nth-child(4n + 1):hover { transform: translate3d(-4px, -4px, 0); }
.cert-card:nth-child(4n + 2):hover { transform: translate3d(4px, -4px, 0); }
.cert-card:nth-child(4n + 3):hover { transform: translate3d(-4px, 4px, 0); }
.cert-card:nth-child(4n + 4):hover { transform: translate3d(4px, 4px, 0); }

.cert-card:hover {
  border-color: rgba(255, 255, 255, 0.2);
  box-shadow: 0 16px 28px rgba(0, 0, 0, 0.24);
}

.cert-card.compact {
  flex: 0 0 min(360px, 82vw);
  scroll-snap-align: start;
}

.cert-image {
  width: 100%;
  height: 112px;
  object-fit: contain;
  border: none;
  border-radius: 0;
  background: transparent;
}

.cert-label { margin: 0 0 0.35rem; color: var(--text-secondary); text-transform: uppercase; letter-spacing: 0.12em; font-size: 0.75rem; }
.cert-card p { margin: 0; color: var(--text-secondary); }

.cert-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  margin-top: 0.95rem;
  padding: 0.42rem 0.7rem;
  border-radius: 999px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  background: rgba(255, 255, 255, 0.04);
  color: #f6f6f6;
  text-decoration: none;
  font-size: 0.82rem;
  font-weight: 600;
  transition: border-color 150ms ease, background-color 150ms ease;
}

.cert-btn:hover {
  border-color: rgba(255, 255, 255, 0.35);
  background: rgba(255, 255, 255, 0.08);
}

.contact-section { padding-bottom: 6rem; }
.contact-section .section-title {
  margin-left: auto;
  margin-right: auto;
  text-align: center;
}
.contact-actions { margin-top: 1.7rem; display: flex; justify-content: center; flex-wrap: wrap; gap: 0.75rem; }
.contact-btn { display: inline-flex; align-items: center; gap: 0.55rem; }

.site-footer {
  border-top: 1px solid var(--line-soft);
  padding: 1.4rem 0;
  color: var(--text-secondary);
  font-size: 0.92rem;
}

.site-footer p { margin: 0; text-align: center; width: 100%; }

.back-to-top {
  position: fixed;
  right: 1.1rem;
  bottom: 1.1rem;
  z-index: 1100;
  width: 2.8rem;
  height: 2.8rem;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: rgba(12, 12, 12, 0.85);
  color: var(--text-primary);
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity 200ms ease, transform 200ms ease, visibility 200ms ease;
}

.back-to-top.is-visible { opacity: 1; visibility: visible; transform: translateY(0); }

.reveal-up { opacity: 0; transform: translateY(20px); }
.reveal-up.is-visible { opacity: 1; transform: translateY(0); transition: opacity 520ms ease, transform 520ms ease; }
.stagger-item { opacity: 0; transform: translateY(16px); animation: staggerIn 620ms ease forwards; }
.stagger-item:nth-child(1) { animation-delay: 80ms; }
.stagger-item:nth-child(2) { animation-delay: 180ms; }
.stagger-item:nth-child(3) { animation-delay: 280ms; }
.stagger-item:nth-child(4) { animation-delay: 380ms; }

@keyframes staggerIn { to { opacity: 1; transform: translateY(0); } }

:focus-visible { outline: 2px solid var(--focus-ring); outline-offset: 2px; }

@media (max-width: 991.98px) {
  .site-rail { display: none; }
  main { margin-left: 0; }
  .hero-content { padding-top: 6.5rem; }
}

@media (max-width: 767.98px) {
  .section-block { padding: 4.6rem 0; }
  .hero-positioning { font-size: 1.16rem; }
  .hero-body { font-size: 0.99rem; }
  .projects-carousel { grid-template-columns: 1fr; }
  .carousel-btn { display: none; }
  .cert-carousel { grid-template-columns: 1fr; }
  .cert-card { flex-basis: 85vw; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
  .reveal-up, .stagger-item { opacity: 1 !important; transform: none !important; }
  .rail-link,
  .mobile-collapse .nav-link,
  .skill-card,
  .project-card,
  .cert-card { transform: none !important; }
}