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

:root {
  /* Updated to warm beige/cream color scheme matching reference site */
  --color-primary: #ff6b35; /* Warm orange for primary actions */
  --color-primary-dark: #e55a2b;
  --color-double: #c89f3d;
  --color-secondary: #ffa726; /* Bright orange accent */
  --color-accent: #10b981;
  --color-bg: #fef5e7; /* Warm cream background */
  --color-bg-light: #fef9f0; /* Lighter cream */
  --color-bg-card: #ffffff;
  --color-text: #2d2d2d; /* Darker text for contrast */
  --color-text-muted: #6b6b6b;
  --color-border: #f0e4d0;
  --color-highlight: #fff3cd;
  --color-nav: #2563eb;
  --color-nav-dark: #1d4ed8;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
  --radius: 12px;
  --radius-sm: 8px;
}

body {
  font-family: "Inter", "Noto Sans JP", -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Sans",
    "Hiragino Kaku Gothic ProN", "Yu Gothic", Meiryo, sans-serif;
  line-height: 1.6;
  color: var(--color-text);
  background: var(--color-bg);
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* Header */
/* Updated header background to cream color */
.header {
  background: var(--color-bg-card);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(8px);
  background: rgba(255, 255, 255, 0.95);
}

.header-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 24px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 14px;
  color: var(--color-text);
  text-decoration: none;
}

.logo-text {
  color: var(--color-text);
}

.home-link {
  margin-left: 15px;
  color: #0073aa;
  text-decoration: none;
}

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

.nav {
  display: flex;
  gap: 32px;
}

.nav a {
  color: var(--color-text-muted);
  text-decoration: none;
  font-weight: 500;
  font-size: 15px;
  transition: color 0.2s;
}

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

/* ===== Hamburger Button ===== */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
}

.hamburger span {
  width: 24px;
  height: 2px;
  background: #1d4ed8;
  border-radius: 2px;
  transition: all 0.3s ease;
}

/* ===== Mobile Nav ===== */
.mobile-nav {
  position: fixed;
  top: 0;
  right: 0;
  width: 280px;              /* ← 小さめ */
  height: 100vh;
  background: rgba(255, 255, 255, 0.94);
  box-shadow: -8px 0 24px rgba(0,0,0,0.12);
  transform: translateX(100%);
  transition: transform 0.3s ease;
  z-index: 1200;

  display: flex;
  flex-direction: column;
  padding-top: 72px;         /* ヘッダー分の余白 */
}


.mobile-nav a {
  padding: 16px 20px;
  text-decoration: none;
  color: #111827;
  font-weight: 500;
  border-bottom: 1px solid #f3f4f6;
}

.mobile-nav a:hover {
  background: #f9fafb;
}

.mobile-cta {
  color: #1d4ed8;
  font-weight: 700;
}

/* ===== Open State ===== */
.mobile-nav.open {
  display: flex;
  transform: translateX(0);
}



/* Hero Section */
/* Updated hero background gradient */
.hero {
  padding: 80px 0;
  background: linear-gradient(180deg, var(--color-bg) 0%, var(--color-bg-light) 100%);
}

.hero-content {
  max-width: 900px;
  margin: 0 auto;
  text-align: center;
}


/* Updated hero badge color to orange */
.hero-badge {
  display: inline-block;
  padding: 8px 16px;
  background: var(--color-primary);
  color: white;
  border-radius: 24px;
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 24px;
}

.hero-title {
  font-size: 48px;
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 24px;
  color: var(--color-text);
}

.hero-subtitle {
  font-size: 20px;
  color: var(--color-text-muted);
  margin-bottom: 48px;
  line-height: 1.6;
}

.hero-problems {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-bottom: 48px;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

/* Updated problem item background */
.problem-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px 24px;
  background: var(--color-bg-card);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-sm);
  text-align: left;
  font-size: 16px;
  border: 1px solid var(--color-border);
}

.problem-icon {
  font-size: 24px;
  flex-shrink: 0;
}

/* Updated solution box background */
.hero-solution {
  background: var(--color-bg-card);
  padding: 48px;
  border-radius: var(--radius);
  box-shadow: var(--shadow-md);
  margin-bottom: 48px;
  border: 1px solid var(--color-border);
}

.solution-title {
  font-size: 28px;
  font-weight: 700;
  margin-bottom: 32px;
  color: var(--color-text);
}

.solution-features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 32px;
}

.solution-feature {
  text-align: center;
}

.solution-number {
  font-size: 48px;
  font-weight: 800;
  color: var(--color-primary);
  margin-bottom: 8px;
}

.solution-text {
  font-size: 16px;
  color: var(--color-text-muted);
  font-weight: 500;
}

/* CTA Button */
.cta-button {
  display: inline-block;
  padding: 16px 40px;
  background: var(--color-primary);
  color: white;
  text-decoration: none;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 16px;
  transition: all 0.2s;
  box-shadow: var(--shadow-md);
}

.cta-button:hover {
  background: var(--color-primary-dark);
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.cta-button.large {
  padding: 20px 48px;
  font-size: 18px;
}

/* Method Section */
/* Updated method section background */
.method-section {
  padding: 80px 0;
  background: var(--color-bg-light);
}

.section-title {
  font-size: 40px;
  font-weight: 800;
  text-align: center;
  margin-bottom: 24px;
  color: var(--color-text);
}

.section-subtitle {
  font-size: 18px;
  color: var(--color-text-muted);
  text-align: center;
  margin-bottom: 64px;
}

.method-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 32px;
}

/* Updated method card styling */
.method-card {
  background: var(--color-bg-card);
  padding: 32px;
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--color-border);
  transition: all 0.3s;
}

.method-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-4px);
}

.method-number {
  font-size: 14px;
  font-weight: 700;
  color: var(--color-primary);
  background: rgba(37, 99, 235, 0.1);
  padding: 4px 12px;
  border-radius: 4px;
  display: inline-block;
  margin-bottom: 16px;
}

.method-card h3 {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--color-text);
}

.method-card p {
  font-size: 15px;
  color: var(--color-text-muted);
  line-height: 1.7;
}

/* ===== Simple Download Section ===== */
.download-simple {
  padding: 48px 0;
  background: var(--color-bg-light);
}

.download-box.simple {
  max-width: 720px;
  margin: 0 auto;
  padding: 32px 36px;
  background: var(--color-bg-card);
  border-radius: 16px;
  border: 1px solid #e5e7eb;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.04);
  text-align: center;
  position: relative;
}

/* バッジ */
.download-badge {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: #1d4ed8;
  background: rgba(29, 78, 216, 0.08);
  padding: 4px 10px;
  border-radius: 999px;
  margin-bottom: 16px;
}

/* キャッチコピー */
.download-catch {
  font-size: 1.4rem;
  font-weight: 600;
  color: #111827;
  margin-bottom: 8px;
}

/* タイトル（少し控えめ） */
.download-title {
  font-size: 1rem;
  font-weight: 400;
  color: #6b7280;
  margin-bottom: 20px;
}

/* 説明文 */
.download-text {
  font-size: 0.95rem;
  line-height: 1.7;
  color: #374151;
  margin-bottom: 28px;
}

/* ダウンロードボタン */
.download-btn.sub {
  display: inline-block;
  padding: 14px 28px;
  font-size: 0.95rem;
  font-weight: 600;
  color: #1d4ed8;
  background: #eff6ff;
  border: 2px solid #1d4ed8;
  border-radius: 10px;
  text-decoration: none;
  transition: all 0.25s ease;
}

.download-btn.sub:hover {
  background: #1d4ed8;
  color: #ffffff;
  transform: translateY(-2px);
}

/* 注記 */
.download-note {
  margin-top: 16px;
  font-size: 0.8rem;
  color: #9ca3af;
}


/* Groups Section */
/* Updated groups section background */
.groups-section {
  padding: 80px 0;
  background: var(--color-bg);
}

.type-section {
  margin-bottom: 64px;
  background: var(--color-bg-card);
  padding: 48px;
  border-radius: var(--radius);
  box-shadow: var(--shadow-md);
  border: 1px solid var(--color-border);
}

.type-header {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 16px;
  flex-wrap: wrap;
}

.type-title {
  font-size: 32px;
  font-weight: 800;
  color: var(--color-text);
}

/* Updated type badge color to orange */
.type-badge {
  padding: 6px 16px;
  background: var(--color-primary);
  color: white;
  border-radius: 20px;
  font-size: 14px;
  font-weight: 600;
}

.type-description {
  font-size: 18px;
  color: var(--color-text-muted);
  margin-bottom: 32px;
  line-height: 1.7;
}

/* Added new group card styles for verb groups */
/* Updated group card background with cream tone */
.group-card {
  background: var(--color-bg-light);
  border: 2px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 24px;
  margin-bottom: 24px;
  transition: all 0.2s;
}

.group-card:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-md);
}

.group-card-header {
  font-size: 1.3rem;        /* 大きめ */
  font-weight: 400;         /* 細字 */
  color: #475569;           /* 少し青みのあるグレー */   
  background: var(--color-bg-light); /* カードと同じ */
  padding: 6px 12px;
  border-radius: 8px;
  display: inline-block;
  margin-bottom: 12px;
  letter-spacing: 0.05em;
}

.verb-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

/* Increased verb font size for better readability */
/* Updated verb item background */
.verb-item {
  font-size: 24px;
  font-weight: 500;
  color: var(--color-text);
  font-family: "Inter", -apple-system, BlinkMacSystemFont, sans-serif;
  padding: 12px 16px;
  background: var(--color-bg-card);
  border-radius: 6px;
  transition: background 0.2s;
  line-height: 1.3;
  border: 1px solid var(--color-border);
}

.verb-item:hover {
  background: rgba(255, 107, 53, 0.05);
  border-color: var(--color-primary);
}

.verb-item .meaning {
  color: var(--color-text-muted);
  font-size: 16px;
  font-family: "Noto Sans JP", -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Sans",
    "Hiragino Kaku Gothic ProN", "Yu Gothic", Meiryo, sans-serif;
  margin-left: 12px;
}

/* Added highlight class for special alphabets */
.verb-item .highlight {
  color: var(--color-primary);
  font-weight: 700;
}

.verb-item .double {
  color: var(--color-double);
  font-weight: 700;
}

.verb-item .base {
  color: var(--color-primary);
  font-weight: 700;
}

.verb-item .past {
  color: var(--color-secondary);
  font-weight: 700;
}

.verb-item .prefix {
  color: var(--color-accent);
  font-weight: 600;
}

.verb-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 20px;
}

.verb-card {
  background: var(--color-bg-light);
  padding: 20px;
  border-radius: var(--radius-sm);
  border: 2px solid var(--color-border);
  transition: all 0.2s;
}

.verb-card:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.verb-card.highlight {
  background: rgba(37, 99, 235, 0.05);
  border-color: var(--color-primary);
}

.verb-card.related {
  background: rgba(16, 185, 129, 0.05);
  border-color: var(--color-accent);
}

.verb-base {
  font-size: 22px;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 8px;
}

.verb-forms {
  font-size: 14px;
  color: var(--color-text);
  font-weight: 500;
  margin-bottom: 8px;
  font-family: "Courier New", monospace;
}

.verb-meaning {
  font-size: 14px;
  color: var(--color-text-muted);
}

.verb-note {
  font-size: 12px;
  color: var(--color-accent);
  font-weight: 600;
  margin-top: 8px;
  padding: 4px 8px;
  background: rgba(16, 185, 129, 0.1);
  border-radius: 4px;
  display: inline-block;
}

/* Subgroups */
.subgroup {
  margin-bottom: 40px;
}

.subgroup:last-child {
  margin-bottom: 0;
}

.subgroup-title {
  font-size: 20px;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 20px;
  padding-left: 16px;
  border-left: 4px solid var(--color-primary);
}

/* Features Section */
.features-section {
  padding: 80px 0;
  background: var(--color-bg-light);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 32px;
}

.feature-card {
  text-align: center;
  padding: 32px;
}

.feature-icon {
  font-size: 64px;
  margin-bottom: 20px;
}

.feature-card h3 {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--color-text);
}

.feature-card p {
  font-size: 15px;
  color: var(--color-text-muted);
  line-height: 1.7;
}

/* CTA Section */
/* Updated CTA section gradient with orange tones */
.cta-section {
  padding: 80px 0;
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
  color: white;
}

.cta-content {
  text-align: center;
  max-width: 800px;
  margin: 0 auto;
}

.cta-title {
  font-size: 40px;
  font-weight: 800;
  margin-bottom: 16px;
}

.cta-subtitle {
  font-size: 18px;
  margin-bottom: 40px;
  opacity: 0.9;
}

.cta-benefits {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-bottom: 40px;
  max-width: 500px;
  margin-left: auto;
  margin-right: auto;
}

.benefit-item {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 16px;
  font-weight: 500;
}

.check-icon {
  flex-shrink: 0;
  color: var(--color-accent);
}

/* ===== CTA Button (Primary) ===== */
.cta-button.primary {
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;

  padding: 18px 28px;
  min-width: 280px;

  background: linear-gradient(135deg, #2563eb 0%, #1d4ed8 100%);
  color: #ffffff;
  text-decoration: none;

  border-radius: 14px;
  font-weight: 700;
  font-size: 1.05rem;
  line-height: 1.4;

  box-shadow: 0 10px 24px rgba(37, 99, 235, 0.35);
  transition: all 0.3s ease;
}

/* メイン文言（1行目） */
.cta-button.primary::first-line {
  font-size: 1.15rem;
  letter-spacing: 0.02em;
}

/* 補足文（※から始まる行） */
.cta-button.primary br + * {
  font-size: 0.75rem;
  font-weight: 400;
  color: rgba(255, 255, 255, 0.85);
  line-height: 1.6;
}

/* Hover */
.cta-button.primary:hover {
  background: linear-gradient(135deg, #1d4ed8 0%, #1e40af 100%);
  transform: translateY(-3px);
  box-shadow: 0 16px 32px rgba(37, 99, 235, 0.45);
}

/* Focus（アクセシビリティ） */
.cta-button.primary:focus-visible {
  outline: 3px solid rgba(255, 255, 255, 0.6);
  outline-offset: 3px;
}

.cta-note {
  margin-top: 16px;
  font-size: 14px;
  opacity: 0.8;
}

/* Footer */
.footer {
  background: #333;
  color: white;
  padding: 40px 0 20px;
}

.footer-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
}

.footer-logo img {
  height: 40px;
  filter: brightness(0) invert(1);
}

.footer-nav {
  display: flex;
  gap: 30px;
}

.footer-nav a {
  color: white;
  text-decoration: none;
  transition: color 0.3s;
}

.footer-nav a:hover {
  color: #ff6b35;
}

.footer-bottom {
  display: block;
  text-align: center;
  padding-top: 20px;
  width: 100%;
  border-top: 1px solid #555;
  color: #ccc;
}

/* Updated floating buttons to display side by side */
.floating-buttons {
  position: fixed;
  bottom: 20px;
  right: 20px;
  display: flex;
  gap: 12px;
  z-index: 1000;
}

#chatTopBtn,
#navBtn {
  width: 55px;
  height: 55px;
  border-radius: 50%;
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.25);
  display: flex;
  justify-content: center;
  align-items: center;
  font-size: 20px;
  cursor: pointer;
  transition: bottom 0.3s ease, background-color 0.3s ease, transform 0.3s ease, opacity 0.3s ease;
  color: #fff;
}

#chatTopBtn {
  background: linear-gradient(135deg, #2563eb 0%, #1d4ed8 100%);
  color: #ffffff;
  box-shadow: 0 6px 14px rgba(37, 99, 235, 0.35);
  border: none;
  transition: all 0.25s ease;
}

#chatTopBtn:hover {
  background: linear-gradient(135deg, #1d4ed8 0%, #1e40af 100%);
  transform: translateY(-2px);
}

/* Added styles for navigation button with orange color */
#navBtn {
  background-color: rgba(37, 99, 235, 0.15); /* 通常：薄い青 */
  color: #2563eb;
  border: 1px solid rgba(37, 99, 235, 0.4);
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.08);
  transition: all 0.2s ease;
}

#navBtn:hover {
  background-color: rgba(37, 99, 235, 0.35); /* hover：少し濃く */
  box-shadow: 0 6px 12px rgba(37, 99, 235, 0.25);
  transform: translateY(-1px);
}

#chatTopBtn.hide,
#navBtn.hide {
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease;
}

#chatTopBtn.show,
#navBtn.show {
  opacity: 1;
}

/* Quick Navigation Buttons */
.nav-label {
  width: 100%;
  text-align: center;
  font-size: 0.75rem;
  font-weight: 500;
  color: #2563eb; /* 説明文寄り */
  margin: -0.25rem 0 0.25rem;
  letter-spacing: 0.02em;
}

.quick-nav {
  display: flex;
  gap: 1rem;
  margin-bottom: 3rem;
  flex-wrap: wrap;
  justify-content: center;
}

.quick-nav-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.25rem;
  padding: 1rem 1.5rem;
  background: linear-gradient(135deg, #2563eb 0%, #1d4ed8 100%);
  color: white;
  border-radius: 12px;
  text-decoration: none;
  transition: all 0.3s ease;
  box-shadow: 0 4px 6px rgba(37, 99, 235, 0.2);
  min-width: 100px;
}

.quick-nav-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 12px rgba(37, 99, 235, 0.3);
  background: linear-gradient(135deg, #1d4ed8 0%, #1e40af 100%);
}

.quick-nav-label {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: 0.05em;
}

.quick-nav-desc {
  font-size: 0.75rem;
  opacity: 0.9;
  font-weight: 400;
}

/* Added back to navigation button styles */
.back-to-nav {
  display: flex;
  justify-content: center;
  margin-top: 2rem;
  padding-top: 2rem;
  border-top: 1px solid var(--color-border);
}

.back-to-nav-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  background: var(--color-bg-card);
  color: var(--color-primary);
  border: 2px solid var(--color-primary);
  border-radius: 8px;
  text-decoration: none;
  font-weight: 600;
  font-size: 0.95rem;
  transition: all 0.3s ease;
}

.back-to-nav-btn:hover {
  background: var(--color-primary);
  color: white;
  transform: translateX(-4px);
}

.back-to-nav-btn svg {
  width: 16px;
  height: 16px;
}

.floating-banner-trial {
  position: fixed !important;
  left: 20px;
  bottom: 5px;
  display: flex;
  gap: 12px;
  z-index: 1000;
  transform: none;
}
.floating-banner-trial a {
  display: block;
}

.floating-banner-trial img {
  width: 200px; 
  height: auto;
  display: block;
}


/* Responsive */
@media (max-width: 768px) {
  .nav {
    display: none;
  }

  .hamburger {
    display: flex;
  }

  .hero-title {
    font-size: 32px;
  }

  .hero-subtitle {
    font-size: 16px;
  }

  .section-title {
    font-size: 28px;
  }

  .type-title {
    font-size: 24px;
  }

  .verb-grid {
    grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
    gap: 16px;
  }

  /* Updated responsive styles for new group card layout */
  .group-card {
    padding: 16px;
  }

  /* Updated mobile font size for verbs */
  .verb-item {
    font-size: 18px;
    padding: 10px 12px;
  }

  .verb-item .meaning {
    font-size: 14px;
  }

  .type-section {
    padding: 32px 24px;
  }

  .hero-solution {
    padding: 32px 24px;
  }

  .cta-title {
    font-size: 28px;
  }

  .solution-features {
    grid-template-columns: 1fr;
    gap: 24px;
  }
}

@media (max-width: 640px) {
  .quick-nav {
    gap: 0.75rem;
  }

  .quick-nav-btn {
    padding: 0.75rem 1rem;
    min-width: 80px;
  }

  .quick-nav-label {
    font-size: 1rem;
  }

  .quick-nav-desc {
    font-size: 0.65rem;
  }
}

  .download-box.simple {
    padding: 24px 20px;
  }

  .download-catch {
    font-size: 1.2rem;
  }

  .download-title {
    font-size: 0.95rem;
  }

  .cta-button.primary {
    padding: 16px 20px;
    min-width: auto;
    width: 100%;
    font-size: 1rem;
  }

  .cta-button.primary::first-line {
    font-size: 1.05rem;
  }

@media (max-width: 480px) {
  .container {
    padding: 0 16px;
  }

  .hero {
    padding: 48px 0;
  }

  .method-section,
  .groups-section,
  .features-section,
  .cta-section {
    padding: 48px 0;
  }
  .type-section {
    padding: 24px 16px;
  }

  /* Removed old verb-grid mobile styles */
}