/* =============================================================
   ABCL TECH — AI Learning Hub · Shared Stylesheet
   Unified green-based theme — site brand color (#39b549).
   Used by /ai/ hub page and all course landing pages.
   ============================================================= */

:root {
  --hub-bg: #ffffff;
  --hub-bg-soft: #f8fafc;
  --hub-border: #e5e7eb;
  --hub-border-strong: #d1d5db;
  --hub-text: #0f172a;
  --hub-text-soft: #475569;
  --hub-text-mute: #64748b;

  --hub-accent: #39b549;
  --hub-accent-hover: #2d8c3a;
  --hub-accent-dark: #1f6e2a;
  --hub-accent-soft: #e6f4e8;
  --hub-accent-soft-2: #d1ecd5;
}

body {
  font-family: 'Anek Bangla', 'Roboto', sans-serif;
  background: var(--hub-bg);
  color: var(--hub-text);
  line-height: 1.75;
}

.hub-wrap { max-width: 1100px; margin: 0 auto; padding: 0 1.2rem; }

/* ── HERO (unified site dark + green) ─────────────────── */
.hub-hero {
  background: linear-gradient(135deg, #020617 0%, #0a0f1c 50%, #0f172a 100%);
  background-size: 200% 200%;
  animation: hub-bg-shift 18s ease-in-out infinite;
  color: #ffffff;
  padding: 4rem 1.2rem 3rem;
  text-align: center;
  position: relative;
  overflow: hidden;
}
@keyframes hub-bg-shift {
  0%, 100% { background-position: 0% 50%; }
  50%      { background-position: 100% 50%; }
}
.hub-hero::before {
  content: '';
  position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(74, 222, 128, 0.08) 1px, transparent 1px),
    linear-gradient(90deg, rgba(74, 222, 128, 0.08) 1px, transparent 1px);
  background-size: 44px 44px, 44px 44px;
  mask-image: radial-gradient(ellipse at center, black 30%, transparent 80%);
  -webkit-mask-image: radial-gradient(ellipse at center, black 30%, transparent 80%);
  pointer-events: none;
}
@media (prefers-reduced-motion: reduce) {
  .hub-hero { animation: none; }
}
.hub-hero .brand-chip {
  display: inline-flex; align-items: center; gap: 0.4rem;
  background: rgba(57,181,73,0.18);
  border: 1px solid rgba(57,181,73,0.40);
  color: #86efac;
  font-size: 0.72rem; font-weight: 700; letter-spacing: 1.5px;
  text-transform: uppercase; padding: 0.3rem 0.85rem;
  border-radius: 50px; margin-bottom: 1.1rem;
}
.hub-hero h1 {
  font-family: 'Anek Bangla', sans-serif;
  font-size: clamp(1.8rem, 5vw, 2.8rem);
  color: #f1f5f9;
  font-weight: 700; line-height: 1.25;
  margin-bottom: 0.8rem;
  letter-spacing: -0.01em;
}
.hub-hero h1 .accent { color: #4ade80; }
.hub-hero .hero-en {
  display: block; font-family: 'Roboto', sans-serif;
  font-size: 1.05rem; font-weight: 500;
  color: #cbd5e1; letter-spacing: 0.5px;
  margin-top: 0.3rem;
}
.hub-hero .hero-tagline {
  font-size: 1.05rem; color: #cbd5e1;
  max-width: 720px; margin: 0 auto 1.6rem;
  line-height: 1.85;
}
.hub-hero .hero-meta {
  display: flex; flex-wrap: wrap; gap: 0.6rem;
  justify-content: center; margin-bottom: 1.7rem;
}
.hub-hero .hero-chip {
  background: rgba(255,255,255,0.07);
  border: 1px solid rgba(255,255,255,0.13);
  color: #cbd5e1; padding: 0.3rem 0.85rem;
  border-radius: 50px; font-size: 0.82rem;
  font-family: 'Anek Bangla', sans-serif;
  display: inline-flex; align-items: center; gap: 0.35rem;
}
.hub-hero .hero-chip i { color: #4ade80; font-size: 0.75rem; }

.hub-hero-cta {
  display: inline-flex; align-items: center; gap: 0.55rem;
  background: var(--hub-accent); color: #0f172a;
  padding: 0.85rem 2rem; border-radius: 999px;
  border: 2px solid var(--hub-accent);
  font-family: 'Anek Bangla', sans-serif;
  font-weight: 700; font-size: 1rem;
  text-decoration: none;
  transition: background 0.2s, color 0.2s, transform 0.15s;
}
.hub-hero-cta:hover {
  background: transparent;
  color: var(--hub-accent);
  transform: translateY(-1px);
}

/* ── SECTION ──────────────────────────────────────────── */
.hub-section { padding: 2.8rem 1.2rem; }
.hub-section.alt { background: var(--hub-bg-soft); }
.hub-section-head { text-align: center; margin-bottom: 2rem; }
.hub-section-head h2 {
  font-family: 'Anek Bangla', sans-serif;
  font-size: clamp(1.4rem, 3.5vw, 1.9rem);
  color: var(--hub-text); font-weight: 700;
  margin-bottom: 0.5rem;
}
.hub-section-head .en {
  display: block;
  font-family: 'Roboto', sans-serif;
  font-size: 0.95rem; color: var(--hub-text-mute);
  font-weight: 500; letter-spacing: 0.5px;
  margin-top: 0.2rem;
}
.hub-section-head p {
  color: var(--hub-text-soft);
  max-width: 720px; margin: 0.6rem auto 0;
  font-size: 0.97rem;
}

/* ── COURSE GRID (hub) ────────────────────────────────── */
.course-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.1rem;
}
.course-card {
  background: #fff; border: 1px solid var(--hub-border);
  border-radius: 14px; padding: 1.4rem 1.3rem;
  text-decoration: none; color: inherit;
  display: flex; flex-direction: column; gap: 0.55rem;
  position: relative; overflow: hidden;
  transition: transform 0.18s, box-shadow 0.18s, border-color 0.18s;
}
.course-card::before {
  content: ''; position: absolute;
  top: 0; left: 0; right: 0; height: 3px;
  background: var(--hub-accent);
}
.course-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 14px 28px -10px rgba(57,181,73,0.20);
  border-color: var(--hub-accent);
}
.course-icon {
  width: 44px; height: 44px;
  background: var(--hub-accent-soft);
  color: var(--hub-accent-dark);
  border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  font-size: 1.25rem;
}
.course-card h3 {
  font-family: 'Anek Bangla', sans-serif;
  font-size: 1.15rem; font-weight: 700;
  color: var(--hub-text); margin-top: 0.4rem;
}
.course-card .en {
  font-family: 'Roboto', sans-serif;
  font-size: 0.85rem; color: var(--hub-text-mute);
  font-weight: 500; letter-spacing: 0.3px;
}
.course-card p {
  font-family: 'Anek Bangla', sans-serif;
  font-size: 0.92rem; color: var(--hub-text-soft);
  line-height: 1.7; margin: 0.3rem 0;
}
.course-meta {
  display: flex; flex-wrap: wrap; gap: 0.4rem;
  margin-top: auto; padding-top: 0.6rem;
}
.course-meta span {
  font-size: 0.74rem;
  font-family: 'Anek Bangla', sans-serif;
  background: var(--hub-bg-soft);
  border: 1px solid var(--hub-border);
  color: var(--hub-text-soft);
  padding: 2px 8px; border-radius: 50px;
}
.course-meta span i {
  color: var(--hub-accent);
  margin-right: 4px; font-size: 0.7rem;
}
.course-cta {
  margin-top: 1rem;
  align-self: flex-start;
  display: inline-flex; align-items: center; justify-content: center;
  font-family: 'Anek Bangla', sans-serif;
  color: var(--hub-accent);
  background: transparent;
  border: 1.5px solid var(--hub-accent);
  font-weight: 700; font-size: 0.82rem;
  padding: 0.4rem 1.05rem;
  border-radius: 999px;
  text-align: center;
  transition: background 0.2s ease, color 0.2s ease, transform 0.2s ease;
}
.course-card:hover .course-cta {
  background: var(--hub-accent);
  color: #fff;
  transform: translateY(-1px);
}

/* ── PILLARS / WHY ────────────────────────────────────── */
.pillars {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 1rem;
}
.pillar {
  background: #fff; border: 1px solid var(--hub-border);
  border-radius: 12px; padding: 1.2rem;
  display: flex; gap: 0.75rem;
}
.pillar-ic {
  font-size: 1.4rem; flex-shrink: 0;
  width: 42px; height: 42px;
  background: var(--hub-accent-soft);
  border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
}
.pillar h3 {
  font-family: 'Anek Bangla', sans-serif;
  font-size: 1rem; font-weight: 700;
  color: var(--hub-text); margin-bottom: 0.25rem;
}
.pillar p {
  font-family: 'Anek Bangla', sans-serif;
  font-size: 0.88rem; color: var(--hub-text-soft);
  line-height: 1.7;
}

/* ── FAQ ──────────────────────────────────────────────── */
.faq { max-width: 800px; margin: 0 auto; }
.faq details {
  background: #fff; border: 1px solid var(--hub-border);
  border-radius: 10px; margin-bottom: 0.6rem;
  padding: 0.9rem 1.1rem;
}
.faq summary {
  font-family: 'Anek Bangla', sans-serif;
  font-weight: 700; cursor: pointer;
  color: var(--hub-text); list-style: none;
  display: flex; justify-content: space-between; align-items: center;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: '+'; font-size: 1.4rem; color: var(--hub-accent);
  font-weight: 300; transition: transform 0.2s;
}
.faq details[open] summary::after { transform: rotate(45deg); }
.faq details p {
  margin: 0.7rem 0 0;
  font-family: 'Anek Bangla', sans-serif;
  color: var(--hub-text-soft); font-size: 0.93rem;
  line-height: 1.85;
}

/* ── FOOTER CTA ───────────────────────────────────────── */
.hub-footer-cta {
  background: linear-gradient(135deg, #020617 0%, #0a0f1c 50%, #0f172a 100%);
  text-align: center; padding: 3rem 1.2rem;
  color: #ffffff;
}
.hub-footer-cta h2 {
  font-family: 'Anek Bangla', sans-serif;
  color: #ffffff; font-size: 1.6rem;
  margin-bottom: 0.5rem;
}
.hub-footer-cta p {
  color: rgba(255, 255, 255, 0.85);
  font-family: 'Anek Bangla', sans-serif;
  margin-bottom: 1.4rem;
}

/* ── BREADCRUMB (course pages) ────────────────────────── */
.hub-breadcrumb {
  font-size: 0.85rem; color: var(--hub-text-mute);
  font-family: 'Anek Bangla', sans-serif;
  padding: 0.9rem 1.2rem;
  background: var(--hub-bg-soft);
  border-bottom: 1px solid var(--hub-border);
}
.hub-breadcrumb a { color: var(--hub-accent); text-decoration: none; }
.hub-breadcrumb a:hover { text-decoration: underline; }

/* ── MODULE LIST (course pages) ───────────────────────── */
.module-block { margin-bottom: 2rem; }
.module-head {
  display: flex; align-items: center; gap: 0.7rem;
  padding-bottom: 0.6rem; margin-bottom: 0.9rem;
  border-bottom: 2px solid var(--hub-accent);
}
.module-badge {
  background: var(--hub-accent);
  color: #fff;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.72rem; font-weight: 700; letter-spacing: 1px;
  padding: 4px 10px; border-radius: 4px;
}
.module-title-bn {
  font-family: 'Anek Bangla', sans-serif;
  font-size: 1.1rem; font-weight: 700;
  color: var(--hub-text);
}
.module-title-en {
  font-family: 'Roboto', sans-serif;
  font-size: 0.85rem; color: var(--hub-text-mute);
  margin-left: auto;
}

.lesson-row {
  display: flex; align-items: center; gap: 0.85rem;
  padding: 0.85rem 1rem;
  background: #fff; border: 1px solid var(--hub-border);
  border-radius: 10px; margin-bottom: 0.45rem;
  transition: border-color 0.15s, box-shadow 0.15s;
}
.lesson-row:hover {
  border-color: var(--hub-accent);
  box-shadow: 0 4px 10px rgba(57,181,73,0.08);
}
.lesson-num {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.74rem; font-weight: 700;
  color: var(--hub-accent-dark);
  background: var(--hub-accent-soft);
  padding: 3px 7px; border-radius: 4px;
  min-width: 36px; text-align: center;
}
.lesson-body { flex: 1; min-width: 0; }
.lesson-title-bn {
  font-family: 'Anek Bangla', sans-serif;
  font-size: 0.97rem; font-weight: 600;
  color: var(--hub-text); line-height: 1.45;
}
.lesson-title-en {
  font-family: 'Roboto', sans-serif;
  font-size: 0.78rem; color: var(--hub-text-mute);
  margin-top: 1px;
}
.lesson-meta {
  display: flex; gap: 0.4rem; flex-shrink: 0;
  font-family: 'Anek Bangla', sans-serif;
  font-size: 0.75rem; color: var(--hub-text-mute);
}
.lesson-meta span i { margin-right: 3px; }
.lesson-cta {
  flex-shrink: 0; padding: 0.4rem 0.9rem;
  background: var(--hub-accent);
  color: #fff; border-radius: 6px;
  font-family: 'Anek Bangla', sans-serif;
  font-size: 0.8rem; font-weight: 700;
  text-decoration: none;
}
.lesson-cta:hover { background: var(--hub-accent-hover); }
.lesson-cta.locked {
  background: var(--hub-bg-soft);
  color: var(--hub-text-mute);
  border: 1px solid var(--hub-border);
  cursor: default; pointer-events: none;
}
.lesson-cta.locked::before { content: '🔒 '; }

/* ── OUTCOMES ─────────────────────────────────────────── */
.outcomes-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 0.9rem;
  max-width: 920px; margin: 0 auto;
}
.outcome {
  background: #fff; border: 1px solid var(--hub-border);
  border-radius: 10px; padding: 1rem 1.1rem;
  display: flex; gap: 0.7rem;
}
.outcome i {
  color: var(--hub-accent);
  font-size: 1.1rem; flex-shrink: 0;
  margin-top: 3px;
}
.outcome span {
  font-family: 'Anek Bangla', sans-serif;
  font-size: 0.92rem; color: var(--hub-text);
  line-height: 1.7;
}

/* ── PREREQ / NEXT BANNER ─────────────────────────────── */
.path-banner {
  display: flex; flex-wrap: wrap; gap: 1rem;
  max-width: 920px; margin: 0 auto;
}
.path-card {
  flex: 1; min-width: 250px;
  background: #fff; border: 1px solid var(--hub-border);
  border-radius: 12px; padding: 1.2rem;
  text-decoration: none; color: inherit;
  transition: border-color 0.15s, transform 0.15s;
}
.path-card:hover {
  border-color: var(--hub-accent);
  transform: translateY(-2px);
}
.path-card .label {
  font-family: 'Anek Bangla', sans-serif;
  font-size: 0.78rem; color: var(--hub-text-mute);
  letter-spacing: 0.5px; font-weight: 600;
  margin-bottom: 0.3rem; display: block;
}
.path-card .label i {
  color: var(--hub-accent);
  margin-right: 4px;
}
.path-card .title {
  font-family: 'Anek Bangla', sans-serif;
  font-size: 1.05rem; font-weight: 700;
  color: var(--hub-text);
}
.path-card .en {
  font-family: 'Roboto', sans-serif;
  font-size: 0.82rem; color: var(--hub-text-mute);
  margin-top: 2px;
}

/* ── RESPONSIVE ───────────────────────────────────────── */
@media (max-width: 640px) {
  .hub-section { padding: 2.2rem 1rem; }
  .lesson-row { flex-wrap: wrap; }
  .lesson-meta { width: 100%; padding-left: 44px; }
  .module-title-en { display: none; }
}