:root {
  --learn-green: #3ccc82;
  --learn-green-dark: #188953;
  --learn-ink: #17211d;
  --learn-muted: #5d6e68;
  --learn-border: #dce8e3;
  --learn-bg: #fbfdfc;
  --learn-soft: #eef8f2;
  --learn-surface: #ffffff;
  --learn-footer: #1b1b1b;
}

* {
  box-sizing: border-box;
}

body.learn-body {
  margin: 0;
  min-height: 100vh;
  background: var(--learn-bg);
  color: var(--learn-ink);
  font-family: "Noto Sans JP", system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
  font-size: 18px;
  line-height: 1.85;
  letter-spacing: 0;
}

a {
  color: inherit;
}

.learn-shell {
  width: min(100% - 32px, 1040px);
  margin: 0 auto;
}

.learn-header {
  position: sticky;
  top: 0;
  z-index: 20;
  border-bottom: 1px solid rgba(23, 33, 29, 0.08);
  background: rgba(251, 253, 252, 0.94);
  backdrop-filter: blur(14px);
}

.learn-header-inner {
  min-height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}

.learn-brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--learn-ink);
  font-size: 14px;
  font-weight: 600;
  text-decoration: none;
}

.learn-brand img {
  width: 92px;
  height: auto;
}

.learn-nav {
  display: flex;
  align-items: center;
  gap: 16px;
  color: var(--learn-muted);
  font-size: 14px;
  font-weight: 600;
}

.learn-nav a {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  text-decoration: none;
}

.learn-nav .learn-nav-cta {
  padding: 0 18px;
  border-radius: 999px;
  background: var(--learn-green);
  color: #fff;
}

.learn-intro {
  padding: 56px 0 34px;
}

.learn-intro-layout {
  display: grid;
  gap: 28px;
}

.learn-kicker {
  margin: 0 0 14px;
  color: var(--learn-green-dark);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.08em;
}

.learn-intro h1 {
  max-width: 840px;
  margin: 0 0 18px;
  font-size: clamp(36px, 11vw, 58px);
  line-height: 1.18;
  font-weight: 600;
}

.learn-intro-lead {
  max-width: 760px;
  margin: 0;
  color: var(--learn-muted);
  font-size: clamp(18px, 4.6vw, 21px);
  line-height: 1.9;
}

.learn-gentle-cta,
.learn-download-section,
.learn-side-card {
  border: 1px solid var(--learn-border);
  border-radius: 8px;
  background: var(--learn-surface);
  box-shadow: 0 14px 34px rgba(46, 111, 78, 0.07);
}

.learn-gentle-cta {
  padding: 22px;
}

.learn-gentle-cta h2,
.learn-download-section h2,
.learn-side-card h2,
.learn-side-card h3 {
  margin: 0 0 8px;
  font-size: 22px;
  line-height: 1.45;
}

.learn-gentle-cta p,
.learn-download-section p,
.learn-side-card p {
  margin: 0 0 18px;
  color: var(--learn-muted);
  font-size: 16px;
  line-height: 1.8;
}

.learn-store-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: center;
}

.learn-store-buttons a {
  min-height: 48px;
  display: inline-flex;
  align-items: center;
}

.learn-store-buttons img {
  height: 44px;
  width: auto;
}

.learn-category-tabs {
  display: flex;
  gap: 10px;
  margin-top: 24px;
  padding-bottom: 4px;
  overflow-x: auto;
}

.learn-category-tabs a {
  min-height: 42px;
  display: inline-flex;
  align-items: center;
  flex: 0 0 auto;
  padding: 0 14px;
  border: 1px solid var(--learn-border);
  border-radius: 999px;
  background: #fff;
  color: var(--learn-muted);
  font-size: 14px;
  font-weight: 700;
  text-decoration: none;
}

.learn-category-tabs a[aria-current="true"] {
  border-color: var(--learn-green);
  background: var(--learn-soft);
  color: var(--learn-green-dark);
}

.learn-section-heading {
  margin: 14px 0 18px;
}

.learn-section-heading h2 {
  margin: 0;
  font-size: clamp(26px, 7vw, 36px);
  line-height: 1.35;
  font-weight: 600;
}

.learn-section-heading p {
  margin: 6px 0 0;
  color: var(--learn-muted);
  font-size: 16px;
}

.learn-list,
.learn-featured-grid {
  display: grid;
  gap: 18px;
}

.learn-featured-grid {
  margin-bottom: 44px;
}

.learn-card {
  display: grid;
  gap: 0;
  padding: 22px;
  border: 1px solid var(--learn-border);
  border-radius: 8px;
  background: var(--learn-surface);
  color: var(--learn-ink);
  text-decoration: none;
  transition: border-color 180ms ease, box-shadow 180ms ease, transform 180ms ease;
}

.learn-card:hover {
  transform: translateY(-2px);
  border-color: rgba(60, 204, 130, 0.55);
  box-shadow: 0 16px 34px rgba(46, 111, 78, 0.11);
}

.learn-card[hidden] {
  display: none;
}

.learn-card-image {
  display: block;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  margin: -22px -22px 20px;
  border-bottom: 1px solid var(--learn-border);
  background: linear-gradient(135deg, #dff4e8, #fff5eb);
}

.learn-card-image img {
  width: 100%;
  height: 100%;
  display: block;
  object-fit: cover;
}

.learn-image-fallback {
  width: 100%;
  height: 100%;
  display: grid;
  align-content: center;
  gap: 10px;
  padding: 22px;
  background:
    radial-gradient(circle at 12% 18%, rgba(60, 204, 130, 0.24), transparent 28%),
    linear-gradient(135deg, #e6f8ee 0%, #fff5eb 100%);
  color: var(--learn-ink);
}

.learn-image-fallback span {
  color: var(--learn-green-dark);
  font-size: 14px;
  font-weight: 800;
  letter-spacing: 0.04em;
}

.learn-image-fallback strong {
  max-width: 28em;
  font-size: clamp(18px, 3vw, 28px);
  line-height: 1.35;
}

.learn-card-image:empty::after {
  content: "olne 読みもの";
  width: 100%;
  height: 100%;
  display: grid;
  place-items: center;
  color: var(--learn-green-dark);
  font-size: 15px;
  font-weight: 700;
}

.learn-card-body {
  display: grid;
  gap: 10px;
}

.learn-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 12px;
  align-items: center;
  color: var(--learn-muted);
  font-size: 14px;
  font-weight: 700;
  line-height: 1.5;
}

.learn-category {
  color: var(--learn-green-dark);
}

.learn-audio-badge {
  min-height: 26px;
  display: inline-flex;
  align-items: center;
  padding: 0 9px;
  border-radius: 999px;
  background: var(--learn-soft);
  color: var(--learn-green-dark);
  font-size: 12px;
}

.learn-card h3 {
  margin: 0;
  font-size: clamp(23px, 6vw, 31px);
  line-height: 1.45;
  font-weight: 600;
}

.learn-card p {
  margin: 0;
  color: var(--learn-muted);
  font-size: 18px;
  line-height: 1.9;
}

.learn-card-action {
  display: inline-flex;
  align-items: center;
  min-height: 46px;
  margin-top: 6px;
  color: var(--learn-green-dark);
  font-size: 16px;
  font-weight: 700;
}

.learn-download-section {
  margin: 44px 0 56px;
  padding: 26px;
  background: linear-gradient(180deg, #ffffff 0%, #f0faf4 100%);
}

.learn-download-section h2 {
  font-size: clamp(26px, 7vw, 36px);
}

.learn-feature-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 9px;
  margin: 18px 0;
}

.learn-feature-pills span {
  min-height: 34px;
  display: inline-flex;
  align-items: center;
  padding: 0 12px;
  border-radius: 999px;
  background: var(--learn-soft);
  color: var(--learn-green-dark);
  font-size: 13px;
  font-weight: 700;
}

.learn-article-layout {
  display: grid;
  gap: 22px;
  padding: 28px 0 56px;
}

.learn-article {
  overflow: hidden;
  border: 1px solid var(--learn-border);
  border-radius: 8px;
  background: var(--learn-surface);
}

.learn-article-cover {
  aspect-ratio: 16 / 9;
  background: linear-gradient(135deg, #dff4e8, #fff5eb);
}

.learn-article-cover img {
  width: 100%;
  height: 100%;
  display: block;
  object-fit: cover;
}

.learn-article-body {
  padding: clamp(24px, 6vw, 44px);
}

.learn-breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 18px;
  color: var(--learn-muted);
  font-size: 14px;
}

.learn-breadcrumb a {
  color: var(--learn-green-dark);
  text-decoration: none;
}

.learn-article h1 {
  margin: 14px 0 20px;
  font-size: clamp(32px, 9vw, 48px);
  line-height: 1.28;
  font-weight: 600;
}

.learn-summary {
  margin: 24px 0;
  padding: 20px;
  border-left: 4px solid var(--learn-green);
  background: var(--learn-soft);
  color: var(--learn-ink);
  font-size: 18px;
  line-height: 1.9;
  font-weight: 600;
}

.learn-teaser {
  margin: 0 0 24px;
  color: var(--learn-muted);
  font-size: 19px;
  line-height: 2;
}

.learn-paywall {
  margin-top: 28px;
  padding: 24px;
  border-radius: 8px;
  background: var(--learn-footer);
  color: #fff;
}

.learn-paywall h2 {
  margin: 0 0 10px;
  font-size: clamp(24px, 6vw, 32px);
  line-height: 1.45;
}

.learn-paywall p {
  margin: 0;
  color: rgba(255, 255, 255, 0.78);
  font-size: 17px;
}

.learn-paywall .learn-feature-pills span {
  background: #e8f7ee;
}

.learn-side {
  display: grid;
  gap: 16px;
}

.learn-side-card {
  padding: 22px;
}

.learn-app-features {
  background: linear-gradient(180deg, #ffffff 0%, #f0faf4 100%);
}

.learn-side-kicker {
  margin: 0 0 8px;
  color: var(--learn-green-dark);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0.06em;
}

.learn-feature-list {
  display: grid;
  gap: 14px;
  margin: 18px 0 20px;
}

.learn-feature-list div {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: 2px 12px;
  padding-top: 14px;
  border-top: 1px solid var(--learn-border);
}

.learn-feature-list span {
  grid-row: span 2;
  width: 34px;
  height: 34px;
  display: inline-grid;
  place-items: center;
  border-radius: 999px;
  background: var(--learn-soft);
  color: var(--learn-green-dark);
  font-size: 12px;
  font-weight: 800;
}

.learn-feature-list strong {
  color: var(--learn-ink);
  font-size: 16px;
  line-height: 1.55;
}

.learn-feature-list p {
  margin: 0;
  color: var(--learn-muted);
  font-size: 14px;
  line-height: 1.75;
}

.learn-side-feature-link {
  min-height: 46px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  border-radius: 999px;
  background: var(--learn-green);
  color: #fff;
  font-size: 15px;
  font-weight: 800;
  text-decoration: none;
}

.learn-related-list {
  display: grid;
  gap: 16px;
}

.learn-related-list a {
  display: grid;
  gap: 4px;
  color: var(--learn-ink);
  font-size: 17px;
  font-weight: 700;
  line-height: 1.6;
  text-decoration: none;
}

.learn-related-list span {
  color: var(--learn-muted);
  font-size: 13px;
  font-weight: 600;
}

.learn-footer {
  background: var(--learn-footer);
  color: #fff;
  padding: 42px 0;
  font-size: 14px;
}

.learn-footer-inner {
  display: grid;
  gap: 18px;
}

.learn-footer-logo {
  font-size: 24px;
  font-weight: 600;
}

.learn-footer-logo span {
  font-size: 14px;
  color: rgba(255, 255, 255, 0.72);
}

.learn-footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
}

.learn-footer a {
  color: rgba(255, 255, 255, 0.78);
  text-decoration: none;
}

.learn-footer-copy {
  margin: 0;
  color: rgba(255, 255, 255, 0.55);
}

@media (min-width: 760px) {
  .learn-shell {
    width: min(100% - 56px, 1040px);
  }

  .learn-intro {
    padding: 76px 0 48px;
  }

  .learn-intro-layout {
    grid-template-columns: minmax(0, 1fr) 340px;
    align-items: start;
  }

  .learn-list {
    grid-template-columns: 1fr;
  }

  .learn-card {
    padding: 28px 30px;
    grid-template-columns: 240px minmax(0, 1fr);
    align-items: stretch;
    gap: 28px;
  }

  .learn-card-image {
    min-height: 100%;
    margin: -28px 0 -28px -30px;
    border-right: 1px solid var(--learn-border);
    border-bottom: 0;
    aspect-ratio: auto;
  }

  .learn-card-image img {
    min-height: 100%;
  }

  .learn-download-section {
    padding: 34px;
  }

  .learn-article-layout {
    grid-template-columns: minmax(0, 1fr) 330px;
    align-items: start;
  }

  .learn-side {
    position: sticky;
    top: 92px;
  }

  .learn-footer-inner {
    grid-template-columns: 1fr auto;
    align-items: center;
  }

  .learn-footer-copy {
    grid-column: 1 / -1;
  }
}

@media (max-width: 640px) {
  body.learn-body {
    font-size: 18px;
  }

  .learn-header-inner {
    align-items: flex-start;
    flex-direction: column;
    gap: 6px;
    padding: 14px 0;
  }

  .learn-nav {
    width: 100%;
    overflow-x: auto;
    padding-bottom: 2px;
  }

  .learn-nav a {
    flex: 0 0 auto;
  }
}