:root {
  --sky: #e8f7ff;
  --mint: #d4f5ec;
  --teal: #1abc9c;
  --teal-dark: #16a085;
  --blue: #2980b9;
  --blue-light: #5dade2;
  --yellow: #f9e04b;
  --yellow-dark: #f1c40f;
  --pink: #ff7eb3;
  --coral: #ff6b6b;
  --white: #ffffff;
  --text: #2c3e50;
  --text-light: #546e7a;
  --radius: 20px;
  --shadow: 0 8px 32px rgba(26, 188, 156, 0.13);
}

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

body {
  font-family: 'Nunito', sans-serif;
  background: var(--sky);
  color: var(--text);
  overflow-x: hidden;
}

header {
  background: linear-gradient(135deg, #fff 0%, #e8f7ff 100%);
  border-bottom: 3px solid var(--teal);
  padding: 0 2rem;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 4px 18px rgba(26, 188, 156, 0.15);
}

.header-inner {
  max-width: 1100px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 80px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 14px;
  text-decoration: none;
}

.logo img {
  height: 62px;
  width: auto;
  filter: drop-shadow(0 2px 6px rgba(26, 188, 156, 0.25));
  animation: float 3s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-5px); }
}

.logo-text {
  display: flex;
  flex-direction: column;
  line-height: 0.95;
}

.logo-name {
  font-family: 'Fredoka One', cursive;
  font-size: 2rem;
  color: var(--teal-dark);
  letter-spacing: 1px;
}

.logo-name sup {
  font-family: 'Nunito', sans-serif;
  font-size: 0.58rem;
  line-height: 0;
  margin-left: 2px;
  vertical-align: super;
}

.logo-learning {
  font-size: 1rem;
  font-weight: 800;
  color: #000;
  letter-spacing: 0;
}

nav a {
  font-weight: 700;
  color: var(--text);
  text-decoration: none;
  margin-left: 1.6rem;
  font-size: 0.95rem;
  transition: color 0.2s;
}

nav a:hover {
  color: var(--teal);
}

.nav-cta {
  background: var(--teal);
  color: var(--white) !important;
  padding: 8px 20px;
  border-radius: 50px;
  transition: background 0.2s, transform 0.15s !important;
}

.nav-cta:hover {
  background: var(--teal-dark) !important;
  transform: scale(1.04);
}

.hero,
.page-hero {
  background: linear-gradient(160deg, #d4f5ec 0%, #e8f7ff 60%, #fef9e7 100%);
  padding: 80px 2rem 60px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before,
.page-hero::before {
  content: '';
  position: absolute;
  top: -60px;
  right: -60px;
  width: 340px;
  height: 340px;
  background: radial-gradient(circle, rgba(26, 188, 156, 0.12) 0%, transparent 70%);
  border-radius: 50%;
}

.hero::after,
.page-hero::after {
  content: '';
  position: absolute;
  bottom: -80px;
  left: -40px;
  width: 280px;
  height: 280px;
  background: radial-gradient(circle, rgba(249, 224, 75, 0.18) 0%, transparent 70%);
  border-radius: 50%;
}

.hero-badge,
.tag {
  display: inline-block;
  background: var(--yellow);
  color: var(--text);
  font-weight: 800;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 2px;
  padding: 6px 18px;
  border-radius: 50px;
  margin-bottom: 20px;
  box-shadow: 0 2px 8px rgba(241, 196, 15, 0.3);
}

.hero h1,
.page-hero h1 {
  font-family: 'Fredoka One', cursive;
  font-size: clamp(2.4rem, 5vw, 3.8rem);
  line-height: 1.15;
  color: var(--teal-dark);
  margin-bottom: 18px;
  position: relative;
}

.hero h1 em {
  font-style: normal;
  color: var(--coral);
}

.hero p,
.page-hero p {
  max-width: 660px;
  margin: 0 auto 36px;
  font-size: 1.12rem;
  color: var(--text-light);
  line-height: 1.7;
}

.page-hero p {
  margin-bottom: 0;
}

.hero-btns {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-block;
  font-family: 'Nunito', sans-serif;
  font-weight: 800;
  font-size: 1rem;
  padding: 14px 32px;
  border-radius: 50px;
  text-decoration: none;
  transition: transform 0.2s, box-shadow 0.2s;
  cursor: pointer;
  border: none;
  background: var(--teal);
  color: #fff;
  box-shadow: 0 4px 16px rgba(26, 188, 156, 0.35);
}

.btn:hover {
  transform: translateY(-3px);
  box-shadow: 0 10px 28px rgba(0, 0, 0, 0.12);
}

.btn-primary {
  background: var(--teal);
  color: #fff;
}

.btn-secondary {
  background: #fff;
  color: var(--teal-dark);
  border: 2.5px solid var(--teal);
}

.btn-outline-dark {
  background: #fff;
  color: var(--text);
  border: 2.5px solid var(--text);
  box-shadow: none;
}

.bubble {
  position: absolute;
  border-radius: 50%;
  opacity: 0.55;
  animation: rise linear infinite;
}

@keyframes rise {
  0% { transform: translateY(0) scale(1); opacity: 0.55; }
  100% { transform: translateY(-200px) scale(0.6); opacity: 0; }
}

.stats {
  background: var(--teal);
  color: #fff;
  padding: 28px 2rem;
}

.stats-inner {
  max-width: 1100px;
  margin: 0 auto;
  display: flex;
  justify-content: space-around;
  flex-wrap: wrap;
  gap: 16px;
}

.stat {
  text-align: center;
}

.stat-num {
  font-family: 'Fredoka One', cursive;
  font-size: 2.4rem;
  line-height: 1;
}

.stat-label {
  font-size: 0.82rem;
  font-weight: 700;
  opacity: 0.85;
  text-transform: uppercase;
  letter-spacing: 1.5px;
}

section {
  padding: 70px 2rem;
}

.section-inner {
  max-width: 1100px;
  margin: 0 auto;
}

.section-inner.narrow {
  max-width: 900px;
  background: #fff;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 32px;
}

.section-tag {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 2px;
  color: var(--teal);
  margin-bottom: 10px;
}

h2 {
  font-family: 'Fredoka One', cursive;
  font-size: clamp(1.7rem, 3vw, 2.6rem);
  color: var(--teal-dark);
  margin-bottom: 14px;
}

.section-lead {
  color: var(--text-light);
  font-size: 1.05rem;
  line-height: 1.7;
  max-width: 640px;
  margin-bottom: 48px;
}

.topics,
.timeline-section {
  background: #fff;
}

.cards,
.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 28px;
}

.card {
  background: #fff;
  border-radius: var(--radius);
  padding: 32px 28px;
  box-shadow: var(--shadow);
  transition: transform 0.25s, box-shadow 0.25s;
  position: relative;
  overflow: hidden;
}

.card:hover {
  transform: translateY(-6px);
  box-shadow: 0 16px 42px rgba(26, 188, 156, 0.18);
}

.card-icon {
  font-size: 2.8rem;
  margin-bottom: 14px;
  display: block;
}

.card h2,
.card h3,
.card h4 {
  font-family: 'Fredoka One', cursive;
  font-size: 1.35rem;
  margin-bottom: 10px;
  color: var(--text);
}

.card p,
.card li,
.section-inner.narrow p {
  font-size: 0.93rem;
  line-height: 1.65;
  color: var(--text-light);
}

.card-link {
  display: inline-block;
  margin-top: 18px;
  font-weight: 800;
  font-size: 0.88rem;
  text-decoration: none;
  color: var(--teal);
  letter-spacing: 0.5px;
}

.card-link:hover {
  text-decoration: underline;
}

.article-page {
  max-width: 980px;
}

.article-image {
  display: block;
  width: 100%;
  max-height: 430px;
  object-fit: contain;
  background: #fff;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  margin-bottom: 36px;
}

.article-image:not(.chart-image) {
  object-fit: cover;
}

.chart-image {
  padding: 18px;
}

.article-copy {
  background: #fff;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 34px;
  margin-bottom: 32px;
}

.article-copy h2 {
  margin-bottom: 14px;
}

.article-copy p,
.article-copy li,
.info-card p,
.layer-detail p {
  color: var(--text-light);
  line-height: 1.75;
}

.article-copy p + p {
  margin-top: 14px;
}

.info-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(210px, 1fr));
  gap: 20px;
  margin-bottom: 32px;
}

.info-card,
.layer-detail {
  background: #fff;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.info-card {
  padding: 26px;
  border-top: 5px solid var(--teal);
}

.info-card h3,
.layer-detail h3 {
  font-family: 'Fredoka One', cursive;
  color: var(--text);
  margin-bottom: 8px;
}

.layer-detail-list {
  display: flex;
  flex-direction: column;
  gap: 18px;
  margin-bottom: 32px;
}

.layer-detail {
  display: flex;
  gap: 22px;
  align-items: flex-start;
  padding: 28px;
}

.article-callout {
  background: linear-gradient(135deg, var(--teal-dark) 0%, var(--blue) 100%);
  color: #fff;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  font-family: 'Fredoka One', cursive;
  font-size: clamp(1.35rem, 3vw, 2rem);
  text-align: center;
  padding: 34px;
  margin-bottom: 32px;
}

.article-steps,
.article-list {
  padding-left: 1.3rem;
  margin-top: 18px;
}

.article-steps li + li,
.article-list li + li {
  margin-top: 12px;
}

.card-accent {
  position: absolute;
  top: -20px;
  right: -20px;
  width: 80px;
  height: 80px;
  border-radius: 50%;
  opacity: 0.15;
}

.card-1 { background: linear-gradient(135deg, #fff 0%, #e8f7ff 100%); }
.card-1 .card-accent { background: var(--teal); }
.card-2 { background: linear-gradient(135deg, #fff 0%, #fef9e7 100%); }
.card-2 .card-accent { background: var(--yellow-dark); }
.card-3 { background: linear-gradient(135deg, #fff 0%, #fce4ec 100%); }
.card-3 .card-accent { background: var(--pink); }
.card-4 { background: linear-gradient(135deg, #fff 0%, #e3f2fd 100%); }
.card-4 .card-accent { background: var(--blue); }

.did-you-know {
  background: linear-gradient(135deg, var(--teal-dark) 0%, var(--blue) 100%);
  color: #fff;
  border-radius: var(--radius);
  padding: 52px 48px;
  display: flex;
  align-items: center;
  gap: 40px;
  flex-wrap: wrap;
  box-shadow: 0 12px 40px rgba(26, 188, 156, 0.22);
}

.dyk-icon {
  font-size: 4rem;
  flex-shrink: 0;
}

.dyk-content h3 {
  font-family: 'Fredoka One', cursive;
  font-size: 1.6rem;
  margin-bottom: 10px;
}

.dyk-content p {
  opacity: 0.9;
  line-height: 1.7;
}

.layers {
  background: var(--sky);
}

.layers-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 20px;
}

.layer-card {
  background: #fff;
  border-radius: var(--radius);
  padding: 28px 22px;
  text-align: center;
  box-shadow: var(--shadow);
  border-top: 5px solid var(--teal);
  transition: transform 0.2s;
}

.layer-card:nth-child(2) { border-top-color: var(--yellow-dark); }
.layer-card:nth-child(3) { border-top-color: var(--coral); }
.layer-card:nth-child(4) { border-top-color: var(--blue-light); }
.layer-card:nth-child(5) { border-top-color: var(--pink); }

.layer-card:hover {
  transform: translateY(-4px);
}

.layer-num {
  font-family: 'Fredoka One', cursive;
  font-size: 2rem;
  color: var(--teal);
  display: block;
  margin-bottom: 6px;
}

.layer-card h4 {
  font-family: 'Fredoka One', cursive;
  font-size: 1.1rem;
  margin-bottom: 8px;
  color: var(--text);
}

.layer-card p {
  font-size: 0.85rem;
  color: var(--text-light);
  line-height: 1.55;
}

.timeline {
  position: relative;
  padding-left: 36px;
  border-left: 4px dashed var(--teal);
  display: flex;
  flex-direction: column;
  gap: 32px;
}

.t-item {
  position: relative;
}

.t-dot {
  position: absolute;
  left: -50px;
  top: 4px;
  width: 28px;
  height: 28px;
  background: var(--teal);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-weight: 800;
  font-size: 0.75rem;
  box-shadow: 0 0 0 4px var(--mint);
}

.t-item h4 {
  font-family: 'Fredoka One', cursive;
  font-size: 1.1rem;
  color: var(--teal-dark);
  margin-bottom: 4px;
}

.t-item p {
  font-size: 0.9rem;
  color: var(--text-light);
  line-height: 1.6;
}

.care {
  background: var(--mint);
}

.tips-row {
  display: flex;
  gap: 24px;
  flex-wrap: wrap;
}

.tip {
  flex: 1;
  min-width: 220px;
  background: #fff;
  border-radius: var(--radius);
  padding: 30px 24px;
  box-shadow: var(--shadow);
  display: flex;
  gap: 16px;
  align-items: flex-start;
}

.tip-emoji {
  font-size: 2.2rem;
  flex-shrink: 0;
}

.tip h4 {
  font-family: 'Fredoka One', cursive;
  font-size: 1.05rem;
  margin-bottom: 6px;
}

.tip p {
  font-size: 0.88rem;
  color: var(--text-light);
  line-height: 1.6;
}

.cta-band {
  background: linear-gradient(120deg, var(--yellow) 0%, #ffe082 100%);
  text-align: center;
  padding: 64px 2rem;
}

.cta-band h2 {
  color: var(--text);
}

.cta-band p {
  color: var(--text-light);
  max-width: 500px;
  margin: 0 auto 32px;
  font-size: 1.05rem;
  line-height: 1.7;
}

footer {
  background: var(--text);
  color: rgba(255, 255, 255, 0.75);
  padding: 36px 2rem;
  text-align: center;
  font-size: 0.88rem;
  line-height: 1.8;
}

footer strong {
  color: #fff;
}

footer a {
  color: var(--teal);
  text-decoration: none;
}

@media (max-width: 640px) {
  .header-inner {
    height: 66px;
  }

  nav {
    display: none;
  }

  .logo-name {
    font-size: 1.35rem;
  }

  .logo-learning {
    font-size: 0.82rem;
  }

  .did-you-know {
    padding: 36px 24px;
  }

  .article-copy,
  .layer-detail {
    padding: 24px;
  }

  .layer-detail {
    flex-direction: column;
    gap: 10px;
  }

  section {
    padding: 48px 1.2rem;
  }
}