/* ===========================================================
   LEARN PREVIEW — Duolingo-style editorial layout
   All selectors scoped under .learn-preview-page to avoid
   collisions with other pages.
   =========================================================== */

.learn-preview-page {
  --lp-ink: #0f172a;
  --lp-ink-soft: #334155;
  --lp-ink-muted: #64748b;
  --lp-ink-faint: #94a3b8;

  /* Light blue paper to match the home / other pages (#e7f2fc). */
  --lp-paper: #e7f2fc;
  --lp-paper-deep: #d6e6f7;
  --lp-paper-line: #c8dbef;

  --lp-accent: #2450b8;
  --lp-accent-deep: #1a3a85;
  --lp-accent-soft: #dce5f7;

  --lp-teal: #0f766e;
  --lp-gold: #b5873a;
  --lp-danger: #b91c1c;
  --lp-stone: #c3d1e2;
  --lp-stone-deep: #8fa3bc;

  --lp-shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.06), 0 2px 8px rgba(15, 23, 42, 0.04);
  --lp-shadow-md: 0 4px 12px rgba(15, 23, 42, 0.08), 0 12px 32px rgba(15, 23, 42, 0.06);
  --lp-shadow-lg: 0 12px 32px rgba(15, 23, 42, 0.1), 0 32px 64px rgba(15, 23, 42, 0.1);

  --lp-radius-md: 14px;
  --lp-radius-lg: 22px;
  --lp-radius-xl: 28px;

  /* Match the rest of the site: Space Grotesk for display/headings,
     Inter for body, JetBrains Mono for labels/metrics. */
  --lp-f-display: "Space Grotesk", "Inter", -apple-system, sans-serif;
  --lp-f-body: "Inter", -apple-system, BlinkMacSystemFont, sans-serif;
  --lp-f-grotesk: "Space Grotesk", "Inter", -apple-system, sans-serif;
  --lp-f-mono: "JetBrains Mono", ui-monospace, monospace;

  position: relative;
  min-height: 100vh;
  background: var(--lp-paper);
  color: var(--lp-ink);
  font-family: var(--lp-f-body);
  letter-spacing: -0.005em;
  -webkit-font-smoothing: antialiased;
  /* Push content below the SiteShell fixed navbar (60px tall). */
  padding-top: 60px;
}

.learn-preview-page::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    radial-gradient(ellipse at top left, rgba(15, 23, 42, 0.035), transparent 60%),
    url("data:image/svg+xml;utf8,<svg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' seed='4'/><feColorMatrix values='0 0 0 0 0.06  0 0 0 0 0.09  0 0 0 0 0.16  0 0 0 0.04 0'/></filter><rect width='100%25' height='100%25' filter='url(%23n)'/></svg>");
  mix-blend-mode: multiply;
  z-index: 0;
}

.learn-preview-page button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  cursor: pointer;
}
.learn-preview-page a { color: inherit; text-decoration: none; }
.learn-preview-page svg { display: block; }
.learn-preview-page *,
.learn-preview-page *::before,
.learn-preview-page *::after { box-sizing: border-box; }

/* ========== LAYOUT ========== */
.learn-preview-page .lp-app {
  position: relative;
  z-index: 1;
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 28px 160px;
}

/* ========== STICKY HEADER ========== */
.learn-preview-page .lp-topbar {
  position: relative;
  z-index: 1;
  background: transparent;
  border-bottom: 1px solid var(--lp-paper-line);
}
.learn-preview-page .lp-topbar-inner {
  max-width: 1240px;
  margin: 0 auto;
  padding: 18px 28px 16px;
  display: flex;
  align-items: center;
  gap: 22px;
}
.learn-preview-page .lp-brand {
  display: flex;
  align-items: baseline;
  gap: 10px;
  margin-right: 4px;
}
.learn-preview-page .lp-brand-mark {
  font-family: var(--lp-f-display);
  font-style: normal;
  font-weight: 700;
  font-size: 24px;
  letter-spacing: -0.015em;
  color: var(--lp-ink);
}
.learn-preview-page .lp-brand-slash {
  color: var(--lp-ink-faint);
  font-family: var(--lp-f-mono);
  font-size: 13px;
}
.learn-preview-page .lp-brand-course {
  font-family: var(--lp-f-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--lp-ink-muted);
}

.learn-preview-page .lp-topbar-stats {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-left: auto;
}
.learn-preview-page .lp-stat {
  display: flex;
  align-items: center;
  gap: 9px;
  padding: 9px 14px;
  border: 1px solid var(--lp-paper-line);
  background: rgba(255, 255, 255, 0.6);
  border-radius: 999px;
  transition: transform 0.2s ease, border-color 0.2s ease, background 0.2s ease;
}
.learn-preview-page .lp-stat:hover {
  transform: translateY(-1px);
  border-color: var(--lp-ink-faint);
  background: #ffffff;
}
.learn-preview-page .lp-stat-icon { color: var(--lp-ink); width: 16px; height: 16px; }
.learn-preview-page .lp-stat-value {
  font-family: var(--lp-f-mono);
  font-size: 13px;
  font-weight: 500;
  color: var(--lp-ink);
  letter-spacing: -0.01em;
  font-variant-numeric: tabular-nums;
}
.learn-preview-page .lp-stat-label {
  font-family: var(--lp-f-mono);
  font-size: 10px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--lp-ink-muted);
}
.learn-preview-page .lp-stat--streak .lp-stat-icon { color: var(--lp-gold); }
.learn-preview-page .lp-stat--xp .lp-stat-icon { color: var(--lp-accent); }
.learn-preview-page .lp-stat--goal { padding-right: 10px; }
.learn-preview-page .lp-stat--hearts .lp-stat-icon { color: var(--lp-danger); }

.learn-preview-page .lp-goal-ring {
  position: relative;
  width: 28px;
  height: 28px;
}
.learn-preview-page .lp-goal-ring svg {
  width: 28px;
  height: 28px;
  transform: rotate(-90deg);
}
.learn-preview-page .lp-goal-ring-track { fill: none; stroke: var(--lp-paper-line); stroke-width: 4; }
.learn-preview-page .lp-goal-ring-fill { fill: none; stroke: var(--lp-accent); stroke-width: 4; stroke-linecap: round; transition: stroke-dashoffset 1.4s cubic-bezier(0.2, 0.8, 0.2, 1); }
.learn-preview-page .lp-goal-ring-label {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  font-family: var(--lp-f-mono);
  font-size: 9px;
  font-weight: 500;
  color: var(--lp-ink);
}

/* ========== HERO ========== */
.learn-preview-page .lp-hero {
  padding: 72px 0 56px;
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 60px;
  align-items: end;
  border-bottom: 1px solid var(--lp-paper-line);
}
.learn-preview-page .lp-hero-eyebrow {
  font-family: var(--lp-f-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--lp-ink-muted);
  margin-bottom: 18px;
  display: flex;
  align-items: center;
  gap: 12px;
}
.learn-preview-page .lp-hero-eyebrow::before {
  content: "";
  width: 28px;
  height: 1px;
  background: var(--lp-ink-muted);
}
.learn-preview-page .lp-hero-title {
  font-family: var(--lp-f-display);
  font-weight: 700;
  font-size: clamp(38px, 4.6vw, 64px);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--lp-ink);
  margin: 0;
  max-width: 100%;
}
.learn-preview-page .lp-hero-title em { font-style: normal; color: var(--lp-accent); }

.learn-preview-page .lp-hero-meta {
  display: flex;
  flex-direction: column;
  gap: 16px;
  padding-bottom: 6px;
}
.learn-preview-page .lp-hero-meta-row {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 20px;
  padding: 14px 0;
  border-top: 1px solid var(--lp-paper-line);
}
.learn-preview-page .lp-hero-meta-row:last-child { border-bottom: 1px solid var(--lp-paper-line); }
.learn-preview-page .lp-hero-meta-label {
  font-family: var(--lp-f-mono);
  font-size: 10px;
  font-weight: 500;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--lp-ink-muted);
}
.learn-preview-page .lp-hero-meta-value {
  font-family: var(--lp-f-display);
  font-weight: 600;
  font-size: 22px;
  color: var(--lp-ink);
}
.learn-preview-page .lp-hero-meta-value em { font-style: normal; color: var(--lp-accent); }

/* ========== COURSE SWITCHER ========== */
.learn-preview-page .lp-course-switcher {
  display: flex;
  gap: 8px;
  padding: 32px 0 8px;
  overflow-x: auto;
  scrollbar-width: none;
}
.learn-preview-page .lp-course-switcher::-webkit-scrollbar { display: none; }
.learn-preview-page .lp-course-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 16px;
  border-radius: 999px;
  border: 1px solid var(--lp-paper-line);
  background: rgba(255, 255, 255, 0.5);
  font-family: var(--lp-f-body);
  font-size: 13px;
  font-weight: 600;
  color: var(--lp-ink-soft);
  white-space: nowrap;
  transition: all 0.2s ease;
}
.learn-preview-page .lp-course-chip:hover {
  border-color: var(--lp-ink-faint);
  color: var(--lp-ink);
}
.learn-preview-page .lp-course-chip.lp-active {
  background: var(--lp-ink);
  color: var(--lp-paper);
  border-color: var(--lp-ink);
}
.learn-preview-page .lp-course-chip-count {
  font-family: var(--lp-f-mono);
  font-size: 11px;
  opacity: 0.6;
}

/* ========== UNIT ========== */
.learn-preview-page .lp-unit {
  padding: 80px 0 40px;
  position: relative;
}
.learn-preview-page .lp-unit-header {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 36px;
  align-items: center;
  padding: 38px 40px;
  background: linear-gradient(180deg, #ffffff 0%, #f0f6fd 100%);
  border: 1px solid var(--lp-paper-line);
  border-radius: var(--lp-radius-xl);
  box-shadow: var(--lp-shadow-sm);
  position: relative;
  overflow: hidden;
}
.learn-preview-page .lp-unit-header::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: repeating-linear-gradient(
    180deg,
    transparent 0,
    transparent 31px,
    var(--lp-paper-line) 31px,
    var(--lp-paper-line) 32px
  );
  opacity: 0.35;
  pointer-events: none;
}
.learn-preview-page .lp-unit-header > * { position: relative; z-index: 1; }

.learn-preview-page .lp-unit-chapter {
  font-family: var(--lp-f-display);
  font-style: normal;
  font-weight: 700;
  font-size: 84px;
  line-height: 0.9;
  letter-spacing: -0.03em;
  color: var(--lp-accent);
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.learn-preview-page .lp-unit-chapter-label {
  font-family: var(--lp-f-mono);
  font-style: normal;
  font-weight: 500;
  font-size: 10px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--lp-ink-muted);
}
.learn-preview-page .lp-unit-title-block { min-width: 0; }
.learn-preview-page .lp-unit-title {
  font-family: var(--lp-f-grotesk);
  font-weight: 700;
  font-size: 36px;
  line-height: 1.1;
  letter-spacing: -0.028em;
  color: var(--lp-ink);
  margin: 0 0 10px;
}
.learn-preview-page .lp-unit-desc {
  font-family: var(--lp-f-body);
  font-size: 15px;
  line-height: 1.55;
  color: var(--lp-ink-muted);
  max-width: 54ch;
  margin: 0;
}
.learn-preview-page .lp-unit-cta {
  display: flex;
  flex-direction: column;
  gap: 10px;
  align-items: flex-end;
}
.learn-preview-page .lp-unit-cta-btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 12px 20px;
  background: var(--lp-ink);
  color: var(--lp-paper);
  border-radius: 999px;
  font-family: var(--lp-f-body);
  font-size: 13px;
  font-weight: 600;
  transition: transform 0.2s ease, background 0.2s ease;
}
.learn-preview-page .lp-unit-cta-btn:hover {
  transform: translateY(-1px);
  background: var(--lp-accent);
}
.learn-preview-page .lp-unit-cta-btn svg { width: 14px; height: 14px; }
.learn-preview-page .lp-unit-cta-meta {
  font-family: var(--lp-f-mono);
  font-size: 10px;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--lp-ink-muted);
}
.learn-preview-page .lp-unit--locked .lp-unit-header { background: linear-gradient(180deg, #f0f6fd 0%, #dfeaf8 100%); }
.learn-preview-page .lp-unit--locked .lp-unit-chapter { color: var(--lp-stone-deep); }
.learn-preview-page .lp-unit--locked .lp-unit-title { color: var(--lp-ink-soft); }
.learn-preview-page .lp-unit--locked .lp-unit-cta-btn { background: var(--lp-stone-deep); pointer-events: none; }

/* ========== TREE ========== */
.learn-preview-page .lp-tree {
  position: relative;
  margin: 24px auto 0;
  max-width: 380px;
  /* Extra top padding so the current-lesson callout (which extends
     ~220px above its node) never overlaps the chapter header above. */
  padding: 240px 0 30px;
}
.learn-preview-page .lp-node-row {
  position: relative;
  display: flex;
  justify-content: center;
  margin-bottom: 34px;
  transition: transform 0.3s ease;
}
.learn-preview-page .lp-node-row:nth-child(1) { transform: translateX(0); }
.learn-preview-page .lp-node-row:nth-child(2) { transform: translateX(72px); }
.learn-preview-page .lp-node-row:nth-child(3) { transform: translateX(108px); }
.learn-preview-page .lp-node-row:nth-child(4) { transform: translateX(72px); }
.learn-preview-page .lp-node-row:nth-child(5) { transform: translateX(0); }
.learn-preview-page .lp-node-row:nth-child(6) { transform: translateX(-72px); }
.learn-preview-page .lp-node-row:nth-child(7) { transform: translateX(-108px); }
.learn-preview-page .lp-node-row:nth-child(8) { transform: translateX(-72px); }

.learn-preview-page .lp-node {
  position: relative;
  width: 88px;
  height: 88px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  transition: transform 0.28s cubic-bezier(0.2, 0.8, 0.2, 1);
  cursor: pointer;
}
.learn-preview-page .lp-node:hover { transform: translateY(-3px) scale(1.03); }
.learn-preview-page .lp-node:active { transform: translateY(-1px) scale(0.98); }

.learn-preview-page .lp-node-face {
  width: 72px;
  height: 72px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  position: relative;
  z-index: 2;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.learn-preview-page .lp-node-shadow {
  position: absolute;
  bottom: 4px;
  width: 72px;
  height: 72px;
  border-radius: 50%;
  z-index: 1;
  transition: transform 0.2s ease;
}
.learn-preview-page .lp-node:hover .lp-node-face { transform: translateY(-6px); }

.learn-preview-page .lp-node--done .lp-node-face {
  background: var(--lp-teal);
  color: #ffffff;
  box-shadow: inset 0 -4px 0 rgba(0, 0, 0, 0.18), 0 1px 2px rgba(15, 23, 42, 0.1);
}
.learn-preview-page .lp-node--done .lp-node-shadow { background: #0a5a54; }

.learn-preview-page .lp-node--current .lp-node-face {
  background: var(--lp-paper);
  color: var(--lp-accent);
  border: 3px solid var(--lp-accent);
  box-shadow: inset 0 -4px 0 rgba(36, 80, 184, 0.16), 0 1px 2px rgba(15, 23, 42, 0.1);
}
.learn-preview-page .lp-node--current .lp-node-shadow { background: var(--lp-accent-deep); }
.learn-preview-page .lp-node--current::before {
  content: "";
  position: absolute;
  inset: -4px;
  border-radius: 50%;
  border: 2px solid var(--lp-accent);
  opacity: 0.4;
  animation: lpNodePulse 2.6s ease-out infinite;
  pointer-events: none;
}
@keyframes lpNodePulse {
  0% { transform: scale(0.96); opacity: 0.6; }
  70% { transform: scale(1.22); opacity: 0; }
  100% { transform: scale(1.22); opacity: 0; }
}

.learn-preview-page .lp-node--locked { cursor: not-allowed; }
.learn-preview-page .lp-node--locked .lp-node-face {
  background: var(--lp-stone);
  color: var(--lp-stone-deep);
  box-shadow: inset 0 -4px 0 rgba(0, 0, 0, 0.12);
}
.learn-preview-page .lp-node--locked .lp-node-shadow { background: var(--lp-stone-deep); }
.learn-preview-page .lp-node--locked:hover { transform: none; }
.learn-preview-page .lp-node--locked:hover .lp-node-face { transform: none; }

.learn-preview-page .lp-node--bonus .lp-node-face {
  background: var(--lp-paper);
  color: var(--lp-gold);
  border: 3px dashed var(--lp-gold);
  box-shadow: inset 0 -4px 0 rgba(181, 135, 58, 0.16);
}
.learn-preview-page .lp-node--bonus .lp-node-shadow { background: #8a6828; }

/* ========== RESET ALL ROW ========== */
.learn-preview-page .lp-reset-row {
  margin-top: 72px;
  text-align: center;
}
.learn-preview-page .lp-reset-all {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 18px;
  border: 1px solid var(--lp-paper-line);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.6);
  font-family: var(--lp-f-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--lp-ink-muted);
  transition: all 0.2s ease;
}
.learn-preview-page .lp-reset-all:hover {
  color: var(--lp-danger);
  border-color: var(--lp-danger);
  background: #ffffff;
}

/* Disabled CTA button for locked chapters */
.learn-preview-page .lp-unit-cta-btn[disabled] {
  background: var(--lp-stone-deep);
  color: #ffffff;
  cursor: not-allowed;
  pointer-events: none;
  opacity: 0.8;
}
.learn-preview-page .lp-unit-cta-btn[disabled]:hover {
  transform: none;
  background: var(--lp-stone-deep);
}

.learn-preview-page .lp-node-icon { width: 28px; height: 28px; }
.learn-preview-page .lp-node--current .lp-node-icon { animation: lpIconBob 2.6s ease-in-out infinite; }
@keyframes lpIconBob {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-2px); }
}

/* Hover-reveal label pill under each node */
.learn-preview-page .lp-node-label {
  position: absolute;
  top: calc(100% + 12px);
  left: 50%;
  transform: translate(-50%, -6px);
  padding: 6px 12px;
  border-radius: 8px;
  background: var(--lp-ink);
  color: #fff;
  font-family: var(--lp-f-mono);
  font-size: 9px;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  white-space: nowrap;
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity 0.2s ease, transform 0.2s ease, visibility 0.2s;
  z-index: 10;
}
.learn-preview-page .lp-node-label::before {
  content: "";
  position: absolute;
  bottom: 100%;
  left: 50%;
  transform: translateX(-50%);
  border: 5px solid transparent;
  border-bottom-color: var(--lp-ink);
}
.learn-preview-page .lp-node:hover .lp-node-label,
.learn-preview-page .lp-node:focus-visible .lp-node-label,
.learn-preview-page .lp-node:focus .lp-node-label {
  opacity: 1;
  visibility: visible;
  transform: translate(-50%, 0);
}

.learn-preview-page .lp-node-callout {
  position: absolute;
  top: -8px;
  left: 50%;
  transform: translate(-50%, -100%);
  width: 280px;
  background: var(--lp-ink);
  color: var(--lp-paper);
  border-radius: var(--lp-radius-lg);
  padding: 20px 22px;
  box-shadow: var(--lp-shadow-lg);
  z-index: 20;
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity 0.22s ease, transform 0.22s ease, visibility 0.22s;
}
.learn-preview-page .lp-node--current:hover .lp-node-callout,
.learn-preview-page .lp-node--current:focus-visible .lp-node-callout,
.learn-preview-page .lp-node--current:focus .lp-node-callout,
.learn-preview-page .lp-node--done:hover .lp-node-callout,
.learn-preview-page .lp-node--done:focus-visible .lp-node-callout,
.learn-preview-page .lp-node--done:focus .lp-node-callout {
  opacity: 1;
  visibility: visible;
  transform: translate(-50%, -100%);
  pointer-events: auto;
}
.learn-preview-page .lp-callout-done {
  color: var(--lp-green, #2fd16a);
  font-weight: 700;
}
.learn-preview-page .lp-node-callout::after {
  content: "";
  position: absolute;
  bottom: -7px;
  left: 50%;
  transform: translateX(-50%) rotate(45deg);
  width: 14px;
  height: 14px;
  background: var(--lp-ink);
}
@keyframes lpCalloutIn {
  from { opacity: 0; transform: translate(-50%, -90%) scale(0.95); }
  to { opacity: 1; transform: translate(-50%, -100%) scale(1); }
}
.learn-preview-page .lp-callout-eyebrow {
  font-family: var(--lp-f-mono);
  font-size: 9px;
  font-weight: 500;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: #93a0bc;
  margin-bottom: 6px;
}
.learn-preview-page .lp-callout-title {
  font-family: var(--lp-f-grotesk);
  font-size: 20px;
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.018em;
  color: #ffffff;
  margin: 0 0 8px;
}
.learn-preview-page .lp-callout-meta {
  display: flex;
  gap: 14px;
  margin-bottom: 16px;
  font-family: var(--lp-f-mono);
  font-size: 10px;
  letter-spacing: 0.08em;
  color: #93a0bc;
}
.learn-preview-page .lp-callout-meta span { display: inline-flex; align-items: center; gap: 5px; }
.learn-preview-page .lp-callout-meta svg { width: 10px; height: 10px; }
.learn-preview-page .lp-callout-btn {
  width: 100%;
  padding: 13px 18px;
  background: var(--lp-accent);
  color: #ffffff;
  border-radius: 12px;
  font-family: var(--lp-f-body);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.02em;
  display: inline-flex;
  justify-content: center;
  align-items: center;
  gap: 8px;
  box-shadow: inset 0 -3px 0 rgba(0, 0, 0, 0.2);
  transition: transform 0.15s ease, background 0.2s ease;
}
.learn-preview-page .lp-callout-btn:hover { background: #2e5fcf; transform: translateY(-1px); }
.learn-preview-page .lp-callout-btn:active { transform: translateY(1px); box-shadow: inset 0 -1px 0 rgba(0, 0, 0, 0.2); }
.learn-preview-page .lp-callout-btn svg { width: 14px; height: 14px; flex-shrink: 0; }

/* ========== LOADING SHELL ========== */
.learn-preview-page.lp-loading-shell {
  min-height: calc(100vh - 60px);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 18px;
  background: var(--lp-paper);
}
.learn-preview-page .lp-loading-spinner {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: 3px solid var(--lp-paper-line);
  border-top-color: var(--lp-accent);
  animation: lpSpin 0.9s linear infinite;
}
@keyframes lpSpin { to { transform: rotate(360deg); } }
.learn-preview-page .lp-loading-text {
  margin: 0;
  font-family: var(--lp-f-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--lp-ink-muted);
}

/* ========== DAILY QUESTS ========== */
.learn-preview-page .lp-quests {
  margin: 72px 0 0;
  padding: 36px 40px;
  border: 1px solid var(--lp-paper-line);
  border-radius: var(--lp-radius-xl);
  background: #ffffff;
  box-shadow: var(--lp-shadow-sm);
}
.learn-preview-page .lp-quests-title-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin-bottom: 24px;
  border-bottom: 1px solid var(--lp-paper-line);
  padding-bottom: 16px;
}
.learn-preview-page .lp-quests-title {
  font-family: var(--lp-f-display);
  font-style: normal;
  font-weight: 700;
  font-size: 36px;
  letter-spacing: -0.02em;
  color: var(--lp-ink);
  margin: 0;
}
.learn-preview-page .lp-quests-date {
  font-family: var(--lp-f-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--lp-ink-muted);
}
.learn-preview-page .lp-quests-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: var(--lp-paper-line);
  border-radius: var(--lp-radius-md);
  overflow: hidden;
}
.learn-preview-page .lp-quest {
  background: #ffffff;
  padding: 20px 22px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.learn-preview-page .lp-quest-row {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
}
.learn-preview-page .lp-quest-label {
  font-family: var(--lp-f-mono);
  font-size: 9px;
  font-weight: 500;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--lp-ink-muted);
}
.learn-preview-page .lp-quest-text {
  font-family: var(--lp-f-grotesk);
  font-size: 17px;
  font-weight: 700;
  letter-spacing: -0.015em;
  color: var(--lp-ink);
  line-height: 1.25;
  margin: 2px 0 0;
}
.learn-preview-page .lp-quest-reward {
  font-family: var(--lp-f-mono);
  font-size: 10px;
  font-weight: 500;
  color: var(--lp-accent);
  letter-spacing: 0.08em;
}
.learn-preview-page .lp-quest-bar {
  height: 6px;
  background: var(--lp-paper-deep);
  border-radius: 999px;
  overflow: hidden;
  margin-top: 4px;
  position: relative;
}
.learn-preview-page .lp-quest-bar-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--lp-accent), #4a79e0);
  border-radius: 999px;
  transform-origin: left center;
  animation: lpBarFill 1.4s cubic-bezier(0.2, 0.8, 0.2, 1) 0.4s both;
}
@keyframes lpBarFill {
  from { transform: scaleX(0); }
}
.learn-preview-page .lp-quest--done .lp-quest-bar-fill { background: var(--lp-teal); }
.learn-preview-page .lp-quest-count {
  font-family: var(--lp-f-mono);
  font-size: 11px;
  font-weight: 500;
  color: var(--lp-ink-soft);
  font-variant-numeric: tabular-nums;
}

/* ========== REVEAL ANIMATIONS ========== */
.learn-preview-page .lp-reveal {
  opacity: 0;
  transform: translateY(24px);
  animation: lpRevealUp 0.7s cubic-bezier(0.2, 0.8, 0.2, 1) forwards;
}
@keyframes lpRevealUp {
  to { opacity: 1; transform: none; }
}
.learn-preview-page .lp-reveal-delay-1 { animation-delay: 0.1s; }
.learn-preview-page .lp-reveal-delay-2 { animation-delay: 0.2s; }
.learn-preview-page .lp-reveal-delay-3 { animation-delay: 0.3s; }
.learn-preview-page .lp-reveal-delay-4 { animation-delay: 0.4s; }
.learn-preview-page .lp-reveal-delay-5 { animation-delay: 0.5s; }

/* ========== RESPONSIVE ========== */
@media (max-width: 920px) {
  .learn-preview-page .lp-hero { grid-template-columns: 1fr; gap: 32px; padding: 56px 0 40px; }
  .learn-preview-page .lp-unit-header { grid-template-columns: 1fr; gap: 20px; padding: 28px; }
  .learn-preview-page .lp-unit-chapter { font-size: 68px; }
  .learn-preview-page .lp-unit-title { font-size: 32px; }
  .learn-preview-page .lp-unit-cta { align-items: flex-start; }
  .learn-preview-page .lp-quests-grid { grid-template-columns: 1fr; }
  .learn-preview-page .lp-topbar-stats .lp-stat-label { display: none; }
  .learn-preview-page .lp-topbar-stats .lp-stat { padding: 8px 12px; }
  .learn-preview-page .lp-tree { max-width: 320px; }
  .learn-preview-page .lp-node-row:nth-child(2),
  .learn-preview-page .lp-node-row:nth-child(4) { transform: translateX(48px); }
  .learn-preview-page .lp-node-row:nth-child(3) { transform: translateX(72px); }
  .learn-preview-page .lp-node-row:nth-child(6),
  .learn-preview-page .lp-node-row:nth-child(8) { transform: translateX(-48px); }
  .learn-preview-page .lp-node-row:nth-child(7) { transform: translateX(-72px); }
}
@media (max-width: 560px) {
  .learn-preview-page .lp-app { padding: 0 20px 120px; }
  .learn-preview-page .lp-topbar-inner { padding: 14px 20px; gap: 12px; }
  .learn-preview-page .lp-brand-slash,
  .learn-preview-page .lp-brand-course { display: none; }
  .learn-preview-page .lp-hero-title { font-size: 48px; }
  .learn-preview-page .lp-unit-chapter { font-size: 56px; }
  .learn-preview-page .lp-unit-title { font-size: 26px; }
  .learn-preview-page .lp-quests { padding: 24px 20px; }
}