:root {
  --navy: #1a2744;
  --navy-light: #2a3f6b;
  --accent: #3b82f6;
  --accent-hover: #2563eb;
  --gray-50: #f8fafc;
  --gray-100: #f1f5f9;
  --gray-200: #e2e8f0;
  --gray-300: #cbd5e1;
  --gray-500: #64748b;
  --gray-600: #475569;
  --gray-700: #334155;
  --gray-800: #1e293b;
  --white: #ffffff;
  --success: #10b981;
  --danger: #ef4444;
}

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

body {
  font-family: 'Noto Sans JP', -apple-system, BlinkMacSystemFont, sans-serif;
  color: var(--gray-800);
  line-height: 1.8;
  background: var(--white);
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

.container { max-width: 1100px; margin: 0 auto; padding: 0 20px; }

/* Header */
header {
  background: var(--navy);
  color: var(--white);
  padding: 0;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 8px rgba(0,0,0,0.15);
}
header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}
.logo {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--white);
  letter-spacing: 0.5px;
}
.logo span { color: var(--accent); }
nav a {
  color: rgba(255,255,255,0.85);
  margin-left: 28px;
  font-size: 0.9rem;
  font-weight: 500;
  transition: color 0.2s;
}
nav a:hover { color: var(--white); text-decoration: none; }

/* Hero */
.hero {
  background: linear-gradient(135deg, var(--navy) 0%, var(--navy-light) 100%);
  color: var(--white);
  padding: 80px 0;
  text-align: center;
}
.hero h1 { font-size: 2.2rem; margin-bottom: 16px; font-weight: 700; }
.hero p { font-size: 1.1rem; opacity: 0.85; max-width: 600px; margin: 0 auto; }

/* Seminars Grid */
.section { padding: 64px 0; }
.section-title {
  font-size: 1.6rem;
  font-weight: 700;
  text-align: center;
  margin-bottom: 40px;
  color: var(--navy);
}
.seminars-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 24px;
}
.seminar-card {
  border: 1px solid var(--gray-200);
  border-radius: 12px;
  overflow: hidden;
  transition: box-shadow 0.2s, transform 0.2s;
  background: var(--white);
}
.seminar-card:hover {
  box-shadow: 0 8px 24px rgba(0,0,0,0.1);
  transform: translateY(-2px);
}
.card-badge {
  display: inline-block;
  background: var(--accent);
  color: var(--white);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 4px 10px;
  border-radius: 4px;
  margin-bottom: 8px;
}
.card-body { padding: 24px; }
.card-body h3 { font-size: 1.15rem; margin-bottom: 8px; color: var(--gray-800); }
.card-body p { font-size: 0.9rem; color: var(--gray-600); margin-bottom: 12px; }
.card-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 16px;
}
.card-price {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--navy);
}
.card-price small { font-size: 0.8rem; font-weight: 400; color: var(--gray-500); }
.btn {
  display: inline-block;
  background: var(--accent);
  color: var(--white);
  padding: 10px 24px;
  border-radius: 8px;
  font-size: 0.9rem;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: background 0.2s;
  text-align: center;
}
.btn:hover { background: var(--accent-hover); text-decoration: none; }
.btn-lg { padding: 14px 36px; font-size: 1rem; }
.btn-outline {
  background: transparent;
  border: 2px solid var(--accent);
  color: var(--accent);
}
.btn-outline:hover { background: var(--accent); color: var(--white); }

/* About section on top */
.about-brief {
  background: var(--gray-50);
  text-align: center;
}
.about-brief p { max-width: 700px; margin: 0 auto; color: var(--gray-600); font-size: 1rem; }

/* Footer */
footer {
  background: var(--navy);
  color: rgba(255,255,255,0.7);
  padding: 40px 0 24px;
  font-size: 0.85rem;
}
footer .container {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 24px;
}
.footer-links a {
  color: rgba(255,255,255,0.7);
  margin-right: 20px;
}
.footer-links a:hover { color: var(--white); }
.footer-copy { width: 100%; text-align: center; margin-top: 16px; padding-top: 16px; border-top: 1px solid rgba(255,255,255,0.1); }

/* Detail page */
.seminar-detail { padding: 48px 0; }
.seminar-detail h1 { font-size: 1.8rem; margin-bottom: 16px; color: var(--navy); }
.detail-grid { display: grid; grid-template-columns: 2fr 1fr; gap: 40px; }
.detail-info h2 { font-size: 1.2rem; margin: 24px 0 12px; color: var(--navy); }
.detail-info p, .detail-info li { color: var(--gray-600); font-size: 0.95rem; }
.detail-info ul { padding-left: 20px; }
.detail-info ul li { margin-bottom: 6px; }
.detail-sidebar {
  background: var(--gray-50);
  border-radius: 12px;
  padding: 28px;
  position: sticky;
  top: 88px;
  height: fit-content;
}
.detail-sidebar .price-label { font-size: 0.85rem; color: var(--gray-500); }
.detail-sidebar .price-value { font-size: 2rem; font-weight: 700; color: var(--navy); margin-bottom: 4px; }
.detail-sidebar .price-tax { font-size: 0.8rem; color: var(--gray-500); margin-bottom: 20px; }
.detail-sidebar .btn { width: 100%; }
.detail-meta { margin: 16px 0; }
.detail-meta dt { font-size: 0.8rem; color: var(--gray-500); margin-top: 12px; }
.detail-meta dd { font-size: 0.95rem; color: var(--gray-700); }

/* Page */
.page-header {
  background: var(--gray-50);
  padding: 40px 0;
  text-align: center;
}
.page-header h1 { font-size: 1.6rem; color: var(--navy); }
.page-content { padding: 48px 0; max-width: 800px; margin: 0 auto; }
.page-content h2 { font-size: 1.2rem; color: var(--navy); margin: 28px 0 12px; }
.page-content p, .page-content li { color: var(--gray-600); font-size: 0.95rem; margin-bottom: 8px; }
.page-content ul { padding-left: 20px; }
.page-content table { width: 100%; border-collapse: collapse; margin: 16px 0; }
.page-content th, .page-content td { text-align: left; padding: 12px 16px; border-bottom: 1px solid var(--gray-200); font-size: 0.9rem; }
.page-content th { background: var(--gray-50); color: var(--gray-700); font-weight: 600; width: 180px; }

/* Contact form */
.form-group { margin-bottom: 20px; }
.form-group label { display: block; font-size: 0.9rem; font-weight: 600; margin-bottom: 6px; color: var(--gray-700); }
.form-group input, .form-group textarea, .form-group select {
  width: 100%;
  padding: 10px 14px;
  border: 1px solid var(--gray-300);
  border-radius: 8px;
  font-size: 0.95rem;
  font-family: inherit;
  transition: border-color 0.2s;
}
.form-group input:focus, .form-group textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(59,130,246,0.1);
}
.form-group textarea { min-height: 120px; resize: vertical; }

/* Payment modal */
.modal-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.5);
  z-index: 200;
  align-items: center;
  justify-content: center;
}
.modal-overlay.active { display: flex; }
.modal {
  background: var(--white);
  border-radius: 16px;
  padding: 32px;
  max-width: 460px;
  width: 90%;
  max-height: 90vh;
  overflow-y: auto;
}
.modal h2 { font-size: 1.2rem; margin-bottom: 20px; color: var(--navy); }
#card-element {
  padding: 12px;
  border: 1px solid var(--gray-300);
  border-radius: 8px;
  margin-bottom: 20px;
  min-height: 40px;
}
.modal .btn { width: 100%; margin-top: 8px; }
.modal-close {
  float: right;
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--gray-500);
}

/* Responsive */
@media (max-width: 768px) {
  .hero h1 { font-size: 1.6rem; }
  .detail-grid { grid-template-columns: 1fr; }
  .detail-sidebar { position: static; }
  nav { display: none; }
  .seminars-grid { grid-template-columns: 1fr; }
  footer .container { flex-direction: column; }
}

/* Instructor */
.instructor {
  display: flex;
  align-items: center;
  gap: 16px;
  margin: 16px 0;
  padding: 16px;
  background: var(--gray-50);
  border-radius: 8px;
}
.instructor-avatar {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: var(--navy);
  color: var(--white);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  font-weight: 700;
  flex-shrink: 0;
}
.instructor-name { font-weight: 600; color: var(--gray-800); }
.instructor-title { font-size: 0.85rem; color: var(--gray-500); }

/* Features */
.features {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
  text-align: center;
}
.feature-icon { font-size: 2.5rem; margin-bottom: 12px; }
.features h3 { font-size: 1rem; margin-bottom: 8px; color: var(--navy); }
.features p { font-size: 0.9rem; color: var(--gray-600); }

@media (max-width: 768px) {
  .features { grid-template-columns: 1fr; gap: 24px; }
}