/* e-learn.jp — Premium Modern Styles */
@import url('https://fonts.googleapis.com/css2?family=Fredoka:wght@400;600;700&family=Noto+Sans+JP:wght@400;500;700;800&display=swap');

:root {
  /* Vibrant & Friendly Palette */
  --color-primary: #FF8A00;
  --color-primary-hover: #E67A00;
  --color-secondary: #00B4D8;
  --color-accent: #7ED321;
  --color-purple: #9D4EDD;
  
  /* Backgrounds & Text */
  --color-text: #2B2D42;
  --color-text-light: #6C757D;
  --color-bg: #F8F9FA;
  --color-card-bg: #FFFFFF;
  
  /* Gradients */
  --grad-yellow: linear-gradient(135deg, #FFD166 0%, #FF9F1C 100%);
  --grad-blue: linear-gradient(135deg, #48CAE4 0%, #0096C7 100%);
  --grad-green: linear-gradient(135deg, #A7C957 0%, #6A994E 100%);
  --grad-purple: linear-gradient(135deg, #C77DFF 0%, #7B2CBF 100%);
  --grad-orange: linear-gradient(135deg, #FF9E00 0%, #FF6D00 100%);
  --grad-cyan: linear-gradient(135deg, #90E0EF 0%, #00B4D8 100%);
  --grad-hero: linear-gradient(135deg, #FFF7EB 0%, #E0F4FF 100%);

  /* Typography */
  --font-main: 'Noto Sans JP', sans-serif;
  --font-heading: 'Fredoka', 'Noto Sans JP', sans-serif;
  
  /* Utils */
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-full: 999px;
  --shadow-sm: 0 4px 6px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 10px 20px rgba(0, 0, 0, 0.08);
  --shadow-hover: 0 15px 30px rgba(0, 0, 0, 0.12);
}

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

body {
  font-family: var(--font-main);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.3;
}

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.bg-light { background-color: #F0F4F8; }
.text-primary { color: var(--color-primary); }

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.8rem 2rem;
  border-radius: var(--radius-full);
  font-size: 1.1rem;
  font-weight: 700;
  text-decoration: none;
  cursor: pointer;
  border: none;
  transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
  font-family: var(--font-heading);
}

.btn-primary { 
  background: var(--color-primary); 
  color: #fff; 
  box-shadow: 0 4px 15px rgba(255, 138, 0, 0.3);
}
.btn-primary:hover { 
  background: var(--color-primary-hover); 
  transform: translateY(-3px);
  box-shadow: 0 8px 25px rgba(255, 138, 0, 0.4);
}
.btn-large {
  font-size: 1.25rem;
  padding: 1rem 2.5rem;
}
.btn .arrow {
  margin-left: 0.5rem;
  transition: transform 0.3s ease;
}
.btn:hover .arrow {
  transform: translateX(5px);
}

.btn-outline {
  background: transparent;
  color: var(--color-secondary);
  border: 2px solid var(--color-secondary);
}
.btn-outline:hover {
  background: var(--color-secondary);
  color: #fff;
  transform: translateY(-2px);
}

/* Header */
.site-header {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(0,0,0,0.05);
  padding: 1rem 0;
  position: sticky;
  top: 0;
  z-index: 1000;
}
.site-header .container { display: flex; align-items: center; justify-content: space-between; }
.site-logo { 
  font-family: var(--font-heading);
  font-size: 1.75rem; 
  font-weight: 800; 
  color: var(--color-primary); 
  text-decoration: none; 
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.site-nav a { 
  margin-left: 1.5rem; 
  text-decoration: none; 
  color: var(--color-text-light); 
  font-weight: 600; 
  transition: color 0.2s;
}
.site-nav a:hover { color: var(--color-primary); }

/* Hero Section */
.hero {
  background: var(--grad-hero);
  padding: 5rem 0;
  overflow: hidden;
}
.hero-container {
  display: flex;
  align-items: center;
  gap: 4rem;
}
.hero-content {
  flex: 1;
  z-index: 2;
}
.hero .badge {
  display: inline-block;
  background: rgba(255, 138, 0, 0.15);
  color: var(--color-primary);
  padding: 0.4rem 1rem;
  border-radius: var(--radius-full);
  font-weight: 700;
  font-size: 0.9rem;
  margin-bottom: 1.5rem;
}
.hero h1 { 
  font-size: clamp(2.5rem, 5vw, 3.5rem); 
  color: var(--color-text); 
  margin-bottom: 1.5rem; 
  letter-spacing: -0.03em;
}
.hero h1 .highlight {
  color: var(--color-secondary);
  position: relative;
  display: inline-block;
}
.hero h1 .highlight::after {
  content: '';
  position: absolute;
  bottom: 4px;
  left: 0;
  width: 100%;
  height: 8px;
  background: rgba(0, 180, 216, 0.3);
  z-index: -1;
  border-radius: 4px;
}
.hero-sub { 
  font-size: 1.15rem; 
  color: var(--color-text-light); 
  margin-bottom: 2.5rem; 
}
.hero-image-wrapper {
  flex: 1;
  position: relative;
}
.hero-img {
  width: 100%;
  max-width: 500px;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  position: relative;
  z-index: 2;
  transform: perspective(1000px) rotateY(-5deg);
  transition: transform 0.5s ease;
}
.hero-img:hover {
  transform: perspective(1000px) rotateY(0deg) translateY(-10px);
}
.floating-shape {
  position: absolute;
  border-radius: 50%;
  z-index: 1;
  opacity: 0.6;
}
.shape-1 {
  width: 100px; height: 100px;
  background: var(--grad-yellow);
  top: -20px; right: -20px;
  animation: float 6s ease-in-out infinite;
}
.shape-2 {
  width: 60px; height: 60px;
  background: var(--grad-blue);
  bottom: 20px; left: -30px;
  animation: float 4s ease-in-out infinite reverse;
}

@keyframes float {
  0% { transform: translateY(0); }
  50% { transform: translateY(-20px); }
  100% { transform: translateY(0); }
}

/* Sections Common */
.section-header {
  text-align: center;
  margin-bottom: 3rem;
}
.section-header h2 {
  font-size: 2.2rem;
  margin-bottom: 0.5rem;
}
.section-header p {
  color: var(--color-text-light);
  font-size: 1.1rem;
}
.features-section { padding: 5rem 0; }
.tools-section { padding: 5rem 0; }

/* Features */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
}
.feature-card {
  background: var(--color-card-bg);
  border-radius: var(--radius-lg);
  padding: 2.5rem 2rem;
  text-align: center;
  box-shadow: var(--shadow-sm);
  border: 1px solid rgba(0,0,0,0.03);
}
.feature-icon {
  width: 70px;
  height: 70px;
  margin: 0 auto 1.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
  border-radius: 20px;
  transform: rotate(-5deg);
}
.bg-yellow { background: var(--grad-yellow); color: white; }
.bg-blue { background: var(--grad-blue); color: white; }
.bg-green { background: var(--grad-green); color: white; }

.feature-card h3 {
  font-size: 1.3rem;
  margin-bottom: 1rem;
}
.feature-card p {
  color: var(--color-text-light);
  font-size: 0.95rem;
}

/* Tools */
.category-title {
  font-size: 1.5rem;
  margin-bottom: 1.5rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.category-title .icon { font-size: 1.8rem; }
.mt-4 { margin-top: 4rem; }

/* Difficulty table */
.difficulty-table-wrap {
  margin: 2.5rem 0 3rem;
  background: #fff;
  border-radius: 16px;
  padding: 1.5rem;
  box-shadow: 0 2px 12px rgba(0,0,0,0.06);
}
.difficulty-table-title {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 1rem;
  color: var(--color-text);
}
.difficulty-table-scroll { overflow-x: auto; }
.difficulty-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.88rem;
  min-width: 600px;
}
.difficulty-table th {
  background: #F0F4F8;
  padding: 0.6rem 0.9rem;
  text-align: left;
  font-weight: 700;
  color: var(--color-text-light);
  font-size: 0.82rem;
  white-space: nowrap;
}
.difficulty-table td {
  padding: 0.6rem 0.9rem;
  border-bottom: 1px solid #F0F0F0;
  vertical-align: top;
  line-height: 1.5;
}
.difficulty-table tr:last-child td { border-bottom: none; }
.difficulty-table .grade-cell {
  font-weight: 700;
  color: var(--color-primary);
  white-space: nowrap;
}
.difficulty-note {
  font-size: 0.82rem;
  color: var(--color-text-light);
  margin-top: 0.75rem;
}

.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 2rem;
}
.tool-card {
  background: var(--color-card-bg);
  border-radius: var(--radius-lg);
  text-decoration: none;
  color: var(--color-text);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}
.hover-lift {
  transition: transform 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275), box-shadow 0.3s ease;
}
.hover-lift:hover { 
  transform: translateY(-8px); 
  box-shadow: var(--shadow-hover); 
}
.tool-card-header {
  height: 120px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.bg-gradient-yellow { background: var(--grad-yellow); }
.bg-gradient-blue { background: var(--grad-blue); }
.bg-gradient-green { background: var(--grad-green); }
.bg-gradient-purple { background: var(--grad-purple); }
.bg-gradient-orange { background: var(--grad-orange); }
.bg-gradient-cyan { background: var(--grad-cyan); }

.tool-icon-large {
  font-size: 3.5rem;
  filter: drop-shadow(0 4px 6px rgba(0,0,0,0.1));
  transition: transform 0.3s ease;
}
.tool-card:hover .tool-icon-large {
  transform: scale(1.1) rotate(5deg);
}

.tool-card-body {
  padding: 1.5rem;
  flex: 1;
  display: flex;
  flex-direction: column;
}
.tool-card-body h4 {
  font-size: 1.2rem;
  margin-bottom: 0.5rem;
}
.target-age {
  font-size: 0.8rem;
  color: var(--color-primary);
  font-weight: 700;
  margin-bottom: 0.8rem;
  background: rgba(255, 138, 0, 0.1);
  display: inline-block;
  padding: 0.2rem 0.6rem;
  border-radius: 4px;
}
.tool-card-body p:last-child {
  font-size: 0.9rem;
  color: var(--color-text-light);
  line-height: 1.5;
}

/* Parents Section */
.parents-section {
  padding: 6rem 0;
  background: #fff;
  position: relative;
}
.parents-container {
  background: var(--grad-hero);
  border-radius: var(--radius-lg);
  padding: 4rem;
  text-align: center;
}
.parents-content {
  max-width: 700px;
  margin: 0 auto;
}
.parents-content h2 {
  font-size: 2rem;
  margin-bottom: 1.5rem;
  color: var(--color-secondary);
}
.parents-content p {
  font-size: 1.1rem;
  color: var(--color-text-light);
  margin-bottom: 1.5rem;
}
.parents-content .btn { margin-top: 1rem; }

/* Footer */
.site-footer {
  background: #2B2D42;
  color: #8D99AE;
  text-align: center;
  padding: 3rem 0;
}
.footer-nav { margin-top: 1.5rem; }
.footer-nav a { 
  color: #8D99AE; 
  margin: 0 1rem; 
  text-decoration: none; 
  font-size: 0.95rem; 
  transition: color 0.2s;
}
.footer-nav a:hover { color: #fff; }
.copyright { margin-top: 2rem; font-size: 0.85rem; }

/* Responsive */
@media (max-width: 900px) {
  .hero-container { flex-direction: column; text-align: center; gap: 2rem; }
  .hero-img { max-width: 400px; transform: none; }
  .hero-img:hover { transform: translateY(-5px); }
  .hero h1 { font-size: 2.2rem; }
}

@media (max-width: 600px) {
  .site-header .container { flex-direction: column; gap: 1rem; }
  .site-nav { display: flex; flex-wrap: wrap; justify-content: center; gap: 0.5rem; }
  .site-nav a { margin: 0 0.5rem; }
  
  .hero { padding: 3rem 0; }
  .hero-actions { display: flex; flex-direction: column; gap: 1rem; }
  
  .features-grid { grid-template-columns: 1fr; }
  .tools-grid { grid-template-columns: 1fr; }
  
  .parents-container { padding: 2rem 1.5rem; }
}