/* ==========================================================================
   Uncodemy Topic Pages — Shared Stylesheet
   Primary: #FF5421 | Heading: Poppins | Body: Inter
   ========================================================================== */

:root {
  --primary: #FF5421;
  --primary-dark: #E0431A;
  --primary-light: #FFF1EC;
  --text-dark: #1F2430;
  --text-muted: #6B7280;
  --border-soft: #EEEEF1;
  --white: #FFFFFF;
  --bg-page: #FAFAFB;
  --shadow-soft: 0 4px 20px rgba(31, 36, 48, 0.06);
  --shadow-hover: 0 10px 30px rgba(255, 84, 33, 0.16);
  --radius-lg: 18px;
  --radius-md: 12px;
  --radius-sm: 8px;
  --max-width: 1400px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: 'Inter', sans-serif;
  color: var(--text-dark);
  background: var(--bg-page);
  line-height: 1.65;
}

h1, h2, h3, h4 {
  font-family: 'Poppins', sans-serif;
  color: var(--text-dark);
  margin: 0 0 12px;
}

a { text-decoration: none; color: inherit; }

img { max-width: 100%; display: block; }

/* ---------- Top Bar ---------- */
.topbar {
  background: var(--white);
  border-bottom: 1px solid var(--border-soft);
  position: sticky;
  top: 0;
  z-index: 50;
}

.topbar-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo img { height: 38px; }

.back-to-course-btn {
  background: var(--primary);
  color: var(--white);
  font-weight: 600;
  font-size: 14px;
  padding: 10px 20px;
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-soft);
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
  white-space: nowrap;
}

.back-to-course-btn:hover {
  background: var(--primary-dark);
  transform: translateY(-2px);
  box-shadow: var(--shadow-hover);
}

/* ---------- Breadcrumb ---------- */
.breadcrumb {
  max-width: var(--max-width);
  margin: 18px auto 0;
  padding: 0 24px;
  font-size: 13px;
  color: var(--text-muted);
}

.breadcrumb a { color: var(--primary); font-weight: 600; }
.breadcrumb span.sep { margin: 0 6px; color: #C9CCD3; }

/* ---------- Page Layout ---------- */
.page-container {
  max-width: var(--max-width);
  margin: 20px auto 60px;
  padding: 0 24px;
  display: grid;
  grid-template-columns: 260px minmax(0, 1fr) 300px;
  gap: 26px;
  align-items: start;
}

/* ---------- Left Sidebar ---------- */
.left-sidebar {
  position: sticky;
  top: 90px;
  background: var(--white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-soft);
  padding: 18px 16px;
  max-height: calc(100vh - 110px);
  overflow-y: auto;
}

.left-sidebar h4 {
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
  padding: 0 8px 10px;
  border-bottom: 1px solid var(--border-soft);
  margin-bottom: 8px;
}

.left-sidebar .topic-link {
  display: block;
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  font-size: 14px;
  color: var(--text-dark);
  margin-bottom: 4px;
  transition: background 0.2s ease, color 0.2s ease;
}

.left-sidebar .topic-link:hover {
  background: var(--primary-light);
  color: var(--primary-dark);
}

.left-sidebar .topic-link.active {
  background: var(--primary);
  color: var(--white);
  font-weight: 600;
}

/* ---------- Main Content ---------- */
.main-content { min-width: 0; }

.content-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-soft);
  padding: 34px 38px;
  animation: fadeIn 0.5s ease both;
}

.content-card h1 {
  font-size: 30px;
  line-height: 1.3;
  margin-bottom: 6px;
}

.content-card .subtitle {
  color: var(--text-muted);
  font-size: 15px;
  margin-bottom: 22px;
}

.content-card h2 {
  font-size: 21px;
  margin-top: 28px;
}

.content-card p { margin: 0 0 16px; color: #333844; font-size: 15.5px; }

.content-card ul, .content-card ol {
  margin: 0 0 16px;
  padding-left: 22px;
  color: #333844;
  font-size: 15.5px;
}

.content-card li { margin-bottom: 8px; }

.content-card code {
  background: var(--primary-light);
  color: var(--primary-dark);
  padding: 2px 7px;
  border-radius: 5px;
  font-size: 14px;
}

.content-card pre {
  background: #1F2430;
  color: #F1F1F4;
  padding: 16px 18px;
  border-radius: var(--radius-md);
  overflow-x: auto;
  font-size: 13.5px;
  margin: 0 0 18px;
}

.highlight-box {
  background: var(--primary-light);
  border-left: 4px solid var(--primary);
  border-radius: var(--radius-sm);
  padding: 14px 18px;
  margin: 20px 0;
  font-size: 14.5px;
}

/* ---------- Prev / Next Nav ---------- */
.prev-next-nav {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  margin-top: 26px;
}

.prev-next-nav a {
  flex: 1;
  background: var(--white);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-soft);
  padding: 14px 18px;
  font-size: 13px;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.prev-next-nav a:hover { transform: translateY(-3px); box-shadow: var(--shadow-hover); }

.prev-next-nav .label { display: block; color: var(--text-muted); font-size: 12px; margin-bottom: 4px; }
.prev-next-nav .title { font-weight: 600; color: var(--text-dark); font-size: 14px; }
.prev-next-nav .next-link { text-align: right; }
.prev-next-nav .disabled { opacity: 0.4; pointer-events: none; }

/* ---------- CTA Box (bottom of content) ---------- */
.cta-box {
  margin-top: 30px;
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  border-radius: var(--radius-lg);
  padding: 30px 34px;
  color: var(--white);
  box-shadow: var(--shadow-hover);
}

.cta-box h3 { color: var(--white); font-size: 20px; margin-bottom: 8px; }
.cta-box p { color: rgba(255,255,255,0.9); margin-bottom: 16px; }

.cta-box .cta-btn {
  display: inline-block;
  background: var(--white);
  color: var(--primary-dark);
  font-weight: 700;
  padding: 12px 24px;
  border-radius: var(--radius-sm);
  transition: transform 0.2s ease;
}

.cta-box .cta-btn:hover { transform: scale(1.04); }

/* ---------- Right Sidebar ---------- */
.right-sidebar {
  position: sticky;
  top: 90px;
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.batch-card, .help-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-soft);
  padding: 22px;
  animation: fadeIn 0.6s ease both;
}

.batch-card .badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--primary-light);
  color: var(--primary-dark);
  font-size: 12px;
  font-weight: 700;
  padding: 6px 12px;
  border-radius: 20px;
  margin-bottom: 12px;
  animation: floaty 3s ease-in-out infinite;
}

.batch-card h4 { font-size: 17px; margin-bottom: 2px; }
.batch-card .course-name { color: var(--primary); font-weight: 700; font-size: 15px; margin-bottom: 14px; }

.batch-meta { font-size: 13.5px; color: var(--text-muted); margin-bottom: 4px; }
.batch-meta b { color: var(--text-dark); }

.countdown-wrap {
  margin: 16px 0;
  background: var(--primary-light);
  border-radius: var(--radius-md);
  padding: 14px;
  text-align: center;
}

.countdown-label { font-size: 11.5px; color: var(--text-muted); text-transform: uppercase; letter-spacing: 0.05em; margin-bottom: 8px; }

.countdown-timer { display: flex; justify-content: center; gap: 10px; }

.countdown-timer .unit { min-width: 46px; }
.countdown-timer .num { font-family: 'Poppins', sans-serif; font-size: 20px; font-weight: 700; color: var(--primary-dark); }
.countdown-timer .lbl { font-size: 10.5px; color: var(--text-muted); }

.feature-list { list-style: none; padding: 0; margin: 14px 0 0; }
.feature-list li { font-size: 13.5px; padding: 6px 0; display: flex; align-items: center; gap: 8px; color: #333844; }
.feature-list li::before { content: "✓"; color: var(--primary); font-weight: 700; }

.limited-seats {
  text-align: center;
  font-size: 12px;
  font-weight: 700;
  color: var(--primary-dark);
  background: var(--primary-light);
  padding: 6px 10px;
  border-radius: 20px;
  margin: 16px 0 10px;
}

.landing-cta-btn {
  display: block;
  width: 100%;
  text-align: center;
  background: var(--primary);
  color: var(--white);
  font-weight: 700;
  font-size: 15px;
  padding: 13px;
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-soft);
  border: none;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}

.landing-cta-btn:hover {
  background: var(--primary-dark);
  transform: scale(1.03);
  box-shadow: var(--shadow-hover);
}

.help-card h4 { font-size: 15px; margin-bottom: 12px; }

.help-row {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 13.5px;
  padding: 10px 0;
  border-top: 1px solid var(--border-soft);
}

.help-row:first-of-type { border-top: none; }

.help-row a { color: var(--primary-dark); font-weight: 600; }

/* ---------- Footer ---------- */
footer {
  background: var(--white);
  border-top: 1px solid var(--border-soft);
  margin-top: 40px;
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 22px 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
  font-size: 13px;
  color: var(--text-muted);
}

.footer-inner a { color: var(--primary); font-weight: 600; }

/* ---------- Animations ---------- */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes floaty {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-4px); }
}

/* ---------- Mobile menu toggle (tablet/mobile) ---------- */
.mobile-sidebar-toggle {
  display: none;
  background: var(--white);
  border: 1px solid var(--border-soft);
  border-radius: var(--radius-sm);
  padding: 10px 14px;
  font-size: 13px;
  font-weight: 600;
  color: var(--primary-dark);
  margin-bottom: 14px;
  cursor: pointer;
}

/* ---------- Responsive ---------- */
@media (max-width: 1180px) {
  .page-container {
    grid-template-columns: 240px minmax(0, 1fr);
  }
  .right-sidebar {
    grid-column: 1 / -1;
    position: relative;
    top: 0;
    flex-direction: row;
    flex-wrap: wrap;
  }
  .batch-card, .help-card { flex: 1 1 300px; }
}

@media (max-width: 860px) {
  .page-container {
    grid-template-columns: 1fr;
  }
  .left-sidebar {
    position: relative;
    top: 0;
    max-height: none;
    display: none;
  }
  .left-sidebar.open { display: block; }
  .mobile-sidebar-toggle { display: inline-block; }
  .content-card { padding: 26px 20px; }
}

@media (max-width: 560px) {
  .topbar-inner { padding: 12px 16px; }
  .back-to-course-btn { padding: 9px 14px; font-size: 13px; }
  .content-card h1 { font-size: 24px; }
  .content-card { padding: 20px 16px; }
  .cta-box { padding: 22px 20px; }
  .footer-inner { flex-direction: column; text-align: center; }
  .prev-next-nav { flex-direction: column; }
  .prev-next-nav .next-link { text-align: left; }
}