/* ═══════════════════════════════════════
   Senior — Design System (Obsidian Dark)
   ═══════════════════════════════════════ */
:root {
  --primary-400: hsl(210, 85%, 65%);
  --primary-500: hsl(210, 80%, 55%);
  --primary-600: hsl(210, 75%, 45%);
  --primary-700: hsl(210, 70%, 35%);
  --accent-400: hsl(170, 75%, 55%);
  --accent-500: hsl(170, 70%, 45%);
  --neutral-50: hsl(220, 15%, 97%);
  --neutral-100: hsl(220, 13%, 91%);
  --neutral-300: hsl(220, 9%, 62%);
  --neutral-400: hsl(220, 7%, 46%);
  --neutral-700: hsl(220, 14%, 18%);
  --neutral-800: hsl(220, 18%, 11%);
  --neutral-900: hsl(220, 22%, 7%);
  --gradient-hero: linear-gradient(160deg, hsl(220,22%,7%) 0%, hsl(210,30%,12%) 50%, hsl(220,22%,7%) 100%);
  --font-sans: 'Inter', system-ui, sans-serif;
  --font-display: 'Outfit', 'Inter', sans-serif;
  --font-mono: 'JetBrains Mono', monospace;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.5rem;
}

*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }
body {
  font-family: var(--font-sans);
  background: var(--neutral-900);
  color: var(--neutral-100);
  line-height: 1.6;
  overflow-x: hidden;
}

/* ── Background Effects ── */
.bg-grid {
  position: fixed; inset: 0; z-index: 0; pointer-events: none;
  background-image:
    linear-gradient(rgba(255,255,255,0.02) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.02) 1px, transparent 1px);
  background-size: 60px 60px;
}
.bg-glow {
  position: fixed; border-radius: 50%; filter: blur(120px); opacity: 0.15; pointer-events: none; z-index: 0;
}
.bg-glow--1 { width: 600px; height: 600px; background: var(--primary-500); top: -200px; right: -150px; }
.bg-glow--2 { width: 500px; height: 500px; background: var(--accent-500); bottom: -200px; left: -100px; }

/* ── Section Base ── */
.section__container { max-width: 1100px; margin: 0 auto; padding: 0 1.5rem; position: relative; z-index: 1; }
.section__header { text-align: center; margin-bottom: 3.5rem; }
.section__tag {
  display: inline-block; font-size: 0.75rem; font-weight: 600; letter-spacing: 0.1em; text-transform: uppercase;
  color: var(--accent-400); background: hsla(170,75%,55%,0.1); border: 1px solid hsla(170,75%,55%,0.2);
  padding: 0.35rem 1rem; border-radius: 999px; margin-bottom: 1rem;
}
.section__title {
  font-family: var(--font-display); font-size: clamp(2rem, 4vw, 2.75rem); font-weight: 700;
  color: var(--neutral-50); margin-bottom: 0.75rem;
}
.section__desc { font-size: 1.05rem; color: var(--neutral-300); max-width: 600px; margin: 0 auto; }

/* ── Navigation ── */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: hsla(220,22%,7%,0.8); backdrop-filter: blur(16px); border-bottom: 1px solid hsla(220,14%,18%,0.6);
}
.nav__container {
  max-width: 1100px; margin: 0 auto; padding: 0 1.5rem;
  display: flex; align-items: center; justify-content: space-between; height: 64px;
}
.nav__logo { display: flex; align-items: center; gap: 0.6rem; text-decoration: none; }
.nav__logo-icon {
  width: 36px; height: 36px; border-radius: 10px; display: grid; place-items: center;
  background: linear-gradient(135deg, var(--primary-500), var(--accent-500));
  color: #fff; font-family: var(--font-display); font-weight: 800; font-size: 1.1rem;
}
.nav__logo-text { color: var(--neutral-50); font-family: var(--font-display); font-weight: 700; font-size: 1.15rem; }
.nav__links { display: flex; gap: 2rem; list-style: none; }
.nav__links a { color: var(--neutral-300); text-decoration: none; font-size: 0.9rem; font-weight: 500; transition: color 0.2s; }
.nav__links a:hover { color: var(--neutral-50); }
.nav__cta {
  padding: 0.5rem 1.25rem; border-radius: 999px; font-size: 0.85rem; font-weight: 600;
  background: linear-gradient(135deg, var(--primary-500), var(--accent-500)); color: #fff;
  text-decoration: none; transition: opacity 0.2s;
}
.nav__cta:hover { opacity: 0.9; }

/* ── Hero ── */
.hero {
  min-height: 100vh; display: flex; align-items: center; justify-content: center;
  text-align: center; padding: 6rem 1.5rem 4rem; position: relative;
}
.hero__container { position: relative; z-index: 1; }
.hero__badge {
  display: inline-flex; align-items: center; gap: 0.5rem; font-size: 0.8rem; font-weight: 500;
  color: var(--accent-400); background: hsla(170,75%,55%,0.08); border: 1px solid hsla(170,75%,55%,0.15);
  padding: 0.4rem 1rem; border-radius: 999px; margin-bottom: 2rem;
}
.hero__badge-dot {
  width: 8px; height: 8px; border-radius: 50%; background: var(--accent-400);
  animation: pulse-dot 2s ease-in-out infinite;
}
@keyframes pulse-dot { 0%,100% { opacity: 1; } 50% { opacity: 0.3; } }

.hero__title { font-family: var(--font-display); margin-bottom: 1.5rem; }
.hero__title-line { display: block; font-size: clamp(2.5rem, 6vw, 4rem); font-weight: 800; color: var(--neutral-50); line-height: 1.1; }
.hero__title-line--accent {
  background: linear-gradient(135deg, var(--primary-400), var(--accent-400));
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
}
.hero__subtitle { font-size: 1.1rem; color: var(--neutral-300); max-width: 560px; margin: 0 auto 2.5rem; }
.hero__actions { display: flex; gap: 1rem; justify-content: center; flex-wrap: wrap; margin-bottom: 4rem; }

.btn {
  display: inline-flex; align-items: center; gap: 0.5rem; padding: 0.75rem 1.75rem;
  border-radius: 999px; font-size: 0.95rem; font-weight: 600; text-decoration: none; transition: all 0.25s;
}
.btn--primary { background: linear-gradient(135deg, var(--primary-500), var(--accent-500)); color: #fff; }
.btn--primary:hover { transform: translateY(-2px); box-shadow: 0 8px 30px hsla(210,80%,55%,0.3); }
.btn--ghost { color: var(--neutral-300); border: 1px solid var(--neutral-700); }
.btn--ghost:hover { color: var(--neutral-50); border-color: var(--neutral-400); }

/* Reactor */
.reactor { position: relative; width: 180px; height: 180px; margin: 0 auto 3rem; }
.reactor__ring {
  position: absolute; border-radius: 50%; border: 2px solid transparent;
}
.reactor__ring--outer {
  inset: 0; border-color: hsla(210,80%,55%,0.3);
  animation: spin 12s linear infinite;
}
.reactor__ring--middle {
  inset: 20px; border-color: hsla(170,75%,55%,0.4); border-style: dashed;
  animation: spin 8s linear infinite reverse;
}
.reactor__ring--inner {
  inset: 45px; border-color: hsla(210,80%,55%,0.5);
  animation: spin 5s linear infinite;
}
.reactor__core {
  position: absolute; inset: 60px; border-radius: 50%; display: grid; place-items: center;
  background: linear-gradient(135deg, var(--primary-500), var(--accent-500));
  font-family: var(--font-display); font-weight: 900; font-size: 1.5rem; color: #fff;
  box-shadow: 0 0 40px hsla(210,80%,55%,0.4), inset 0 0 20px hsla(170,75%,55%,0.3);
}
.reactor__pulse {
  position: absolute; inset: 55px; border-radius: 50%;
  border: 2px solid hsla(170,75%,55%,0.3);
  animation: reactor-pulse 3s ease-out infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }
@keyframes reactor-pulse {
  0% { transform: scale(1); opacity: 0.6; }
  100% { transform: scale(2.2); opacity: 0; }
}

/* Stats */
.hero__stats { display: flex; justify-content: center; gap: 3rem; flex-wrap: wrap; }
.stat { text-align: center; }
.stat__number {
  display: block; font-family: var(--font-display); font-size: 1.75rem; font-weight: 800;
  background: linear-gradient(135deg, var(--primary-400), var(--accent-400));
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
}
.stat__label { font-size: 0.8rem; color: var(--neutral-400); text-transform: uppercase; letter-spacing: 0.08em; font-weight: 500; }

/* ── Features ── */
.features { padding: 6rem 0; }
.features__grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 1.25rem; }
.feature-card {
  background: hsla(220,18%,11%,0.7); border: 1px solid var(--neutral-700); border-radius: var(--radius-xl);
  padding: 2rem; transition: all 0.3s; position: relative; overflow: hidden;
}
.feature-card:hover { border-color: hsla(210,80%,55%,0.3); transform: translateY(-4px); }
.feature-card__icon {
  width: 48px; height: 48px; border-radius: 12px; display: grid; place-items: center;
  background: hsla(210,80%,55%,0.1); color: var(--primary-400); margin-bottom: 1.25rem;
}
.feature-card__title { font-family: var(--font-display); font-size: 1.15rem; font-weight: 600; color: var(--neutral-50); margin-bottom: 0.5rem; }
.feature-card__desc { font-size: 0.9rem; color: var(--neutral-300); line-height: 1.6; margin-bottom: 1rem; }
.feature-card__tag {
  font-family: var(--font-mono); font-size: 0.72rem; color: var(--accent-400);
  background: hsla(170,75%,55%,0.08); padding: 0.25rem 0.6rem; border-radius: 999px;
}

/* ── Architecture ── */
.architecture { padding: 6rem 0; }
.arch-flow {
  display: flex; align-items: center; justify-content: center; gap: 0.75rem;
  flex-wrap: wrap; margin-bottom: 3rem;
}
.arch-flow__step {
  text-align: center; padding: 1.25rem 1.5rem; background: var(--neutral-800);
  border: 1px solid var(--neutral-700); border-radius: var(--radius-lg); min-width: 130px;
  transition: border-color 0.3s;
}
.arch-flow__step:hover { border-color: var(--primary-500); }
.arch-flow__icon { font-size: 1.75rem; margin-bottom: 0.4rem; }
.arch-flow__label { font-size: 0.85rem; font-weight: 600; color: var(--neutral-50); }
.arch-flow__sub { font-size: 0.72rem; color: var(--neutral-400); margin-top: 0.2rem; }
.arch-flow__arrow { color: var(--primary-400); font-size: 1.25rem; font-weight: 700; }

/* Code Demo */
.code-demo {
  background: var(--neutral-800); border: 1px solid var(--neutral-700); border-radius: var(--radius-xl);
  overflow: hidden; max-width: 580px; margin: 0 auto;
}
.code-demo__header {
  display: flex; align-items: center; gap: 0.75rem; padding: 0.75rem 1rem;
  background: hsla(220,18%,14%,0.8); border-bottom: 1px solid var(--neutral-700);
}
.code-demo__dots { display: flex; gap: 6px; }
.code-demo__dots span { width: 10px; height: 10px; border-radius: 50%; background: var(--neutral-700); }
.code-demo__dots span:first-child { background: hsl(0,60%,50%); }
.code-demo__dots span:nth-child(2) { background: hsl(45,80%,55%); }
.code-demo__dots span:last-child { background: hsl(130,50%,45%); }
.code-demo__title { font-size: 0.75rem; color: var(--neutral-400); font-family: var(--font-mono); }
.code-demo__body {
  padding: 1.25rem; font-family: var(--font-mono); font-size: 0.82rem; line-height: 1.7;
  color: var(--neutral-100); overflow-x: auto;
}
.code-comment { color: var(--neutral-400); }
.code-key { color: var(--primary-400); }
.code-string { color: var(--accent-400); }

/* ── Commands ── */
.commands { padding: 6rem 0; }
.commands__grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 1rem; }
.command-card {
  background: var(--neutral-800); border: 1px solid var(--neutral-700); border-radius: var(--radius-lg);
  padding: 1.25rem; transition: all 0.3s;
}
.command-card:hover { border-color: hsla(170,75%,55%,0.3); transform: translateY(-2px); }
.command-card__category {
  font-size: 0.65rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.08em;
  color: var(--accent-400); margin-bottom: 0.5rem; display: block;
}
.command-card__example {
  font-family: var(--font-mono); font-size: 0.9rem; color: var(--neutral-50); font-weight: 500; margin-bottom: 0.35rem;
}
.command-card__result { font-size: 0.8rem; color: var(--neutral-400); }

/* ── Tech ── */
.tech { padding: 6rem 0; }
.tech__grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(160px, 1fr)); gap: 0.75rem; }
.tech-card {
  text-align: center; padding: 1.25rem; background: var(--neutral-800); border: 1px solid var(--neutral-700);
  border-radius: var(--radius-lg); transition: all 0.3s;
}
.tech-card:hover { border-color: var(--primary-500); transform: translateY(-2px); }
.tech-card__name { font-family: var(--font-mono); font-size: 0.85rem; font-weight: 600; color: var(--neutral-50); margin-bottom: 0.2rem; }
.tech-card__desc { font-size: 0.72rem; color: var(--neutral-400); }

/* ── CTA ── */
.cta { padding: 6rem 0; }
.cta__content {
  text-align: center; padding: 4rem 2rem; border-radius: var(--radius-2xl);
  background: linear-gradient(135deg, hsla(210,30%,15%,0.8), hsla(170,20%,12%,0.8));
  border: 1px solid hsla(210,80%,55%,0.15);
}
.cta__title { font-family: var(--font-display); font-size: clamp(1.75rem, 3vw, 2.25rem); font-weight: 700; color: var(--neutral-50); margin-bottom: 0.75rem; }
.cta__desc { color: var(--neutral-300); margin-bottom: 2rem; }
.cta__code {
  display: inline-block; padding: 0.75rem 2rem; background: var(--neutral-900); border: 1px solid var(--neutral-700);
  border-radius: var(--radius-lg); font-family: var(--font-mono); font-size: 0.95rem; color: var(--accent-400);
}

/* ── Footer ── */
.footer { padding: 2rem 0; border-top: 1px solid var(--neutral-700); }
.footer__content { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 1rem; }
.footer__brand { display: flex; align-items: center; gap: 0.6rem; font-weight: 500; color: var(--neutral-300); }
.footer__copy { font-size: 0.8rem; color: var(--neutral-400); }

/* ── Animations ── */
.fade-up { opacity: 0; transform: translateY(30px); transition: all 0.6s ease-out; }
.fade-up.visible { opacity: 1; transform: translateY(0); }

/* ── Responsive ── */
@media (max-width: 768px) {
  .nav__links { display: none; }
  .arch-flow__arrow { display: none; }
  .arch-flow { gap: 0.5rem; }
  .hero__stats { gap: 1.5rem; }
}