:root {
  --bg: #080c12;
  --bg2: #0d1117;
  --bg3: #111820;
  --panel: #131b24;
  --border: #1e2d3d;
  --border-hi: #2a3f56;
  --orange: #f97316;
  --orange-dim: rgba(249,115,22,0.15);
  --orange-glow: rgba(249,115,22,0.35);
  --teal: #38bdf8;
  --green: #4ade80;
  --purple: #c084fc;
  --muted: #4a6178;
  --soft: #7a95ad;
  --text: #d4e4f0;
  --white: #f0f8ff;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: 'Inter', sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  overflow-x: hidden;
}

/* ── HERO ─────────────────────────────────────── */
.hero {
  min-height: 100svh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 4rem 2rem 6rem;
  position: relative;
  overflow: hidden;
}

/* grid bg */
.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--border) 1px, transparent 1px),
    linear-gradient(90deg, var(--border) 1px, transparent 1px);
  background-size: 60px 60px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 50%, black 30%, transparent 100%);
  opacity: 0.35;
}

/* orange radial bloom */
.hero::after {
  content: '';
  position: absolute;
  top: 40%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 700px;
  height: 400px;
  background: radial-gradient(ellipse, rgba(249,115,22,0.08) 0%, transparent 70%);
  pointer-events: none;
}

.hero-eyebrow {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  letter-spacing: 2.5px;
  text-transform: uppercase;
  color: var(--orange);
  margin-bottom: 1.5rem;
  position: relative;
  z-index: 1;
  opacity: 0;
  animation: fadeUp 0.6s 0.2s forwards;
}

.hero-title {
  font-family: 'JetBrains Mono', monospace;
  font-size: clamp(2rem, 6vw, 4.8rem);
  font-weight: 700;
  line-height: 1.05;
  text-align: center;
  color: var(--white);
  position: relative;
  z-index: 1;
  opacity: 0;
  animation: fadeUp 0.7s 0.35s forwards;
  letter-spacing: -1px;
}

.hero-title .accent { color: var(--orange); }
.hero-title .dim { color: var(--muted); font-weight: 300; }

.hero-sub {
  margin-top: 1.5rem;
  font-size: 1.05rem;
  color: var(--soft);
  text-align: center;
  max-width: 500px;
  line-height: 1.7;
  position: relative;
  z-index: 1;
  opacity: 0;
  animation: fadeUp 0.7s 0.5s forwards;
}

/* compile terminal widget */
.compile-widget {
  margin-top: 3rem;
  position: relative;
  z-index: 2;
  width: min(560px, 90vw);
  opacity: 0;
  animation: fadeUp 0.7s 0.7s forwards;
}

.compile-bar {
  background: #0b1520;
  border: 1px solid var(--border-hi);
  border-bottom: none;
  border-radius: 10px 10px 0 0;
  padding: 9px 14px;
  display: flex;
  align-items: center;
  gap: 7px;
}

.dot { width: 10px; height: 10px; border-radius: 50%; }
.dot-r { background: #ff5f57; }
.dot-y { background: #febc2e; }
.dot-g { background: #28c840; }
.compile-label { font-family: 'JetBrains Mono', monospace; font-size: 11px; color: var(--muted); margin-left: 6px; }

.compile-body {
  background: #060d14;
  border: 1px solid var(--border-hi);
  border-radius: 0 0 10px 10px;
  padding: 20px 22px;
  font-family: 'JetBrains Mono', monospace;
  font-size: clamp(10px, 2.5vw, 12.5px);
  line-height: 1.9;
  min-height: 160px;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.cl { display: block; white-space: nowrap; }
.cl-prompt { color: var(--muted); }
.cl-kw { color: var(--purple); }
.cl-cls { color: var(--teal); }
.cl-str { color: var(--green); }
.cl-cmt { color: #3a5268; font-style: italic; }
.cl-ok { color: var(--green); }
.cl-warn { color: var(--orange); }

.cursor {
  display: inline-block;
  width: 7px;
  height: 13px;
  background: var(--orange);
  vertical-align: middle;
  animation: blink 1s step-end infinite;
}

.hero-cta {
  margin-top: 2.5rem;
  position: relative;
  z-index: 2;
  opacity: 0;
  animation: fadeUp 0.7s 1.2s forwards;
}

.cta-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 28px;
  background: var(--orange);
  color: #fff;
  font-family: 'JetBrains Mono', monospace;
  font-size: 13px;
  font-weight: 600;
  border-radius: 8px;
  text-decoration: none;
  letter-spacing: 0.3px;
  transition: background 0.2s, transform 0.2s, box-shadow 0.2s;
  box-shadow: 0 0 24px var(--orange-glow);
}

.cta-btn:hover {
  background: #fb923c;
  transform: translateY(-2px);
  box-shadow: 0 0 36px rgba(249,115,22,0.5);
}

.stats-row {
  margin-top: 2rem;
  display: flex;
  gap: 2.5rem;
  opacity: 0;
  animation: fadeUp 0.7s 1.4s forwards;
  position: relative;
  z-index: 2;
  flex-wrap: wrap;
  justify-content: center;
}

.stat { text-align: center; }
.stat-num {
  font-family: 'JetBrains Mono', monospace;
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--white);
}
.stat-label {
  font-size: 11px;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-top: 2px;
}
.stat-div { width: 1px; background: var(--border-hi); align-self: stretch; }

/* ── ROADMAP SECTION ─────────────────────────── */
.roadmap-section {
  max-width: 1100px;
  margin: 0 auto;
  padding: 6rem 2rem 8rem;
}

.section-header {
  text-align: center;
  margin-bottom: 5rem;
}

.section-eyebrow {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--orange);
  margin-bottom: 1rem;
}

.section-title {
  font-family: 'JetBrains Mono', monospace;
  font-size: clamp(1.4rem, 3vw, 2.4rem);
  font-weight: 700;
  color: var(--white);
  letter-spacing: -0.5px;
}

.section-sub {
  font-family: 'Inter', sans-serif;
  font-size: 14px;
  color: var(--soft);
  max-width: 560px;
  margin: 1rem auto 0;
  line-height: 1.6;
}

/* sticky track jump-nav */
.track-nav {
  position: sticky;
  top: 0;
  z-index: 30;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
  background: rgba(8,12,18,0.85);
  backdrop-filter: blur(10px);
  padding: 14px 16px;
  border: 1px solid var(--border);
  border-radius: 14px;
  margin-bottom: 3rem;
}

.track-pill {
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
  color: var(--soft);
  text-decoration: none;
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 7px 14px;
  white-space: nowrap;
  transition: border-color 0.2s, color 0.2s, background 0.2s;
}

.track-pill:hover {
  color: var(--tc, var(--orange));
  border-color: var(--tc, var(--orange));
  background: color-mix(in srgb, var(--tc, var(--orange)) 12%, transparent);
}

/* track overview cards */
.track-overview-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 14px;
  margin-bottom: 5rem;
}

.track-card {
  display: flex;
  flex-direction: column;
  gap: 6px;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px;
  text-decoration: none;
  transition: border-color 0.2s, transform 0.2s;
}

.track-card:hover {
  border-color: var(--tc, var(--orange));
  transform: translateY(-3px);
}

.track-card-icon { font-size: 22px; }

.track-card-title {
  font-family: 'JetBrains Mono', monospace;
  font-size: 13px;
  font-weight: 700;
  color: var(--white);
}

.track-card-desc {
  font-size: 12px;
  color: var(--muted);
  line-height: 1.5;
}

/* phase groups */
.phase {
  margin-bottom: 5rem;
}

.phase-header {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 1.5rem;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--border);
  flex-wrap: wrap;
}

.phase-num {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  color: var(--muted);
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 5px;
  padding: 3px 8px;
  white-space: nowrap;
}

.phase-name {
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--soft);
  white-space: nowrap;
}

.phase-line { flex: 1; height: 1px; background: var(--border); min-width: 20px; }

/* course cards grid */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 14px;
}

.course-card {
  display: block;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 22px;
  text-decoration: none;
  color: inherit;
  transition: border-color 0.2s, transform 0.2s, box-shadow 0.2s;
  position: relative;
  overflow: hidden;
}

.course-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--orange), transparent);
  opacity: 0;
  transition: opacity 0.2s;
}

.course-card:hover {
  border-color: var(--border-hi);
  transform: translateY(-3px);
  box-shadow: 0 12px 32px rgba(0,0,0,0.4), 0 0 0 1px rgba(249,115,22,0.1);
}

.course-card:hover::before { opacity: 1; }

.card-tag {
  font-family: 'JetBrains Mono', monospace;
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--orange);
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  gap: 6px;
}

.card-tag::before {
  content: '';
  width: 5px;
  height: 5px;
  background: var(--orange);
  border-radius: 50%;
  box-shadow: 0 0 6px var(--orange-glow);
  flex-shrink: 0;
}

.card-title {
  font-size: 15px;
  font-weight: 600;
  color: var(--white);
  margin-bottom: 8px;
  line-height: 1.3;
}

.card-desc {
  font-size: 12.5px;
  color: var(--muted);
  line-height: 1.6;
  margin: 0;
}

/* special "Enterprise" card */
.course-card.featured {
  background: linear-gradient(135deg, #131b24 0%, #0f1c2a 100%);
  border-color: rgba(249,115,22,0.3);
  grid-column: span 2;
}

.course-card.featured::before { opacity: 1; }
.course-card.featured .card-tag { color: var(--orange); }
.course-card.featured .card-title { font-size: 17px; }

.featured-inner {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: start;
  gap: 20px;
}

.featured-badge {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  background: var(--orange-dim);
  border: 1px solid rgba(249,115,22,0.4);
  color: var(--orange);
  padding: 6px 12px;
  border-radius: 20px;
  white-space: nowrap;
}

/* ── BOOKS ────────────────────────────────────── */
.books-section {
  background: var(--bg2);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding: 5rem 2rem;
}

.books-inner {
  max-width: 900px;
  margin: 0 auto;
}

.books-eyebrow {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--orange);
  margin-bottom: 1rem;
}

.books-header {
  margin-bottom: 2.5rem;
}

.books-title {
  font-family: 'JetBrains Mono', monospace;
  font-size: clamp(1.2rem, 2.5vw, 2rem);
  font-weight: 700;
  color: var(--white);
  letter-spacing: -0.3px;
  margin-bottom: 0.5rem;
}

.books-sub {
  color: var(--soft);
  font-size: 0.95rem;
  margin: 0;
}

.books-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.book-card {
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 24px;
  display: flex;
  gap: 20px;
  transition: border-color 0.2s;
}

.book-card:hover { border-color: var(--orange); }

.book-cover {
  width: 72px;
  min-width: 72px;
  height: 96px;
  border-radius: 5px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 8px;
}

.book-cover-hfj {
  background: linear-gradient(135deg, #1a3a5c, #0f2236);
  border: 1px solid #2a5278;
}

.book-cover-mja {
  background: linear-gradient(135deg, #3a1a0f, #1e0e06);
  border: 1px solid #7a3a1a;
}

.book-cover-title {
  font-family: 'JetBrains Mono', monospace;
  font-size: 9px;
  font-weight: 700;
  color: rgba(255,255,255,0.85);
  text-align: center;
  line-height: 1.4;
  letter-spacing: 0.3px;
}

.book-info { flex: 1; }

.book-phase {
  font-family: 'JetBrains Mono', monospace;
  font-size: 10px;
  color: var(--orange);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 5px;
}

.book-name {
  font-size: 15px;
  font-weight: 600;
  color: var(--white);
  margin-bottom: 2px;
}

.book-author {
  font-size: 12px;
  color: var(--muted);
  margin-bottom: 8px;
  font-style: italic;
}

.book-desc {
  font-size: 12.5px;
  color: var(--soft);
  line-height: 1.6;
  margin-bottom: 10px;
}

.book-tags { display: flex; flex-wrap: wrap; gap: 6px; }

.btag {
  font-family: 'JetBrains Mono', monospace;
  font-size: 10px;
  background: rgba(249,115,22,0.08);
  border: 1px solid rgba(249,115,22,0.2);
  color: var(--orange);
  padding: 2px 8px;
  border-radius: 20px;
}

/* ── FOOTER ───────────────────────────────────── */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 2.5rem 2rem;
  text-align: center;
  font-family: 'JetBrains Mono', monospace;
  font-size: 11.5px;
  color: var(--muted);
}

/* ── ANIMATIONS ───────────────────────────────── */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(18px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes blink {
  50% { opacity: 0; }
}

.reveal {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.reveal.visible { opacity: 1; transform: none; }

/* ── RESPONSIVE ───────────────────────────────── */

/* Tablet (≤900px) */
@media (max-width: 900px) {
  .roadmap-section { padding: 4rem 1.5rem 6rem; }
  .section-header { margin-bottom: 3.5rem; }
  .books-section { padding: 4rem 1.5rem; }
}

/* Phablet (≤680px) */
@media (max-width: 680px) {
  /* Hero */
  .hero { padding: 5rem 1.25rem 4rem; }
  .hero-sub { font-size: 0.95rem; }

  /* Terminal */
  .compile-body { padding: 14px 16px; }

  /* Stats */
  .stats-row { gap: 1.5rem; }
  .stat-num { font-size: 1.3rem; }

  /* Roadmap */
  .roadmap-section { padding: 3.5rem 1.25rem 5rem; }
  .phase { margin-bottom: 3.5rem; }
  .cards-grid { grid-template-columns: 1fr; }
  .course-card.featured { grid-column: span 1; }
  .featured-inner { grid-template-columns: 1fr; }
  .featured-badge { width: fit-content; }

  /* Books */
  .books-section { padding: 3.5rem 1.25rem; }
  .books-grid { grid-template-columns: 1fr; }
  .book-card { flex-direction: column; }
  .book-cover { width: 56px; min-width: 56px; height: 76px; }
}

/* Small mobile (≤400px) */
@media (max-width: 400px) {
  .hero-eyebrow { font-size: 9px; letter-spacing: 1.5px; }
  .compile-label { display: none; }

  /* Collapse stats to a tighter row, hide dividers */
  .stat-div { display: none; }
  .stats-row { gap: 1.25rem; }
  .stat-num { font-size: 1.2rem; }
  .stat-label { font-size: 10px; }

  /* Phase header: let it stack naturally */
  .phase-line { display: none; }

  .cta-btn { padding: 11px 20px; font-size: 12px; }

  .compile-body { font-size: 10px; padding: 12px 14px; }
}

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

/* Mobile Responsive Overrides */
@media (max-width: 768px) {
    .shell, .layout { 
        flex-direction: column !important; 
    }
    .sidebar { 
        width: 100% !important; 
        position: static !important;
        margin-bottom: 20px;
    }
    .main { 
        width: 100% !important; 
        padding: 15px !important;
    }
    .lesson-nav { 
        flex-direction: column; 
        gap: 10px; 
    }
    button, .nav-btn, .btn { 
        min-height: 44px !important; 
        padding: 12px !important;
    }
}