/* Modern Balanced Design for DGSG */
:root {
  --primary-color: #6366F1;
  --primary-hover: #4F46E5;
  --secondary-color: #8B5CF6;
  --accent-color: #EC4899;
  --mint-color: #10B981;
  --sky-color: #06B6D4;
  --text-primary: #1F2937;
  --text-secondary: #6B7280;
  --bg-light: #F9FAFB;
  --bg-white: #FFFFFF;
  --border-color: #E5E7EB;
  --success-color: #10B981;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Hiragino Sans', 'Hiragino Kaku Gothic ProN', 'Noto Sans JP', sans-serif;
  line-height: 1.6;
  color: var(--text-primary);
  background: linear-gradient(135deg, #EEF2FF 0%, #F3E8FF 50%, #FCE7F3 100%);
  min-height: 100vh;
  padding: 20px;
  margin: 0;
  width: 100%;
  overflow-x: hidden;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  width: 100%;
}

/* Hero Section */
.hero-section {
  text-align: center;
  padding: 40px 20px;
  margin-bottom: 40px;
}

.hero-section h1 {
  font-size: 2.5rem;
  background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 16px;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.hero-section .subtitle {
  font-size: 1.125rem;
  color: var(--text-secondary);
  margin-bottom: 32px;
  font-weight: 500;
}

/* Login Panel */
.login-panel {
  background: var(--bg-white);
  border-radius: 20px;
  box-shadow: var(--shadow-xl);
  padding: 48px;
  margin-bottom: 32px;
  text-align: center;
  border: 1px solid var(--border-color);
}

.login-panel h2 {
  font-size: 1.875rem;
  color: var(--text-primary);
  margin-bottom: 12px;
  font-weight: 600;
}

.login-panel p {
  color: var(--text-secondary);
  margin-bottom: 32px;
  font-size: 1.0625rem;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
  color: white;
  border: none;
  padding: 16px 48px;
  font-size: 1.125rem;
  font-weight: 600;
  border-radius: 12px;
  cursor: pointer;
  transition: all 0.3s ease;
  box-shadow: var(--shadow-md);
  display: inline-block;
  text-decoration: none;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.btn-primary:active {
  transform: translateY(0);
}

/* Information Section */
.information {
  background: var(--bg-white);
  border-radius: 20px;
  box-shadow: var(--shadow-xl);
  padding: 48px;
  margin-bottom: 32px;
  border: 1px solid var(--border-color);
}

.information h1 {
  font-size: 2rem;
  color: var(--text-primary);
  margin-bottom: 24px;
  font-weight: 700;
  text-align: center;
}

.information h2 {
  font-size: 1.5rem;
  color: var(--text-primary);
  margin-top: 40px;
  margin-bottom: 16px;
  font-weight: 600;
  padding-bottom: 12px;
  border-bottom: 3px solid var(--primary-color);
  display: flex;
  align-items: center;
  gap: 8px;
}

.information h2::before {
  content: '📖';
  font-size: 1.25rem;
}

.information p {
  color: var(--text-secondary);
  margin-bottom: 16px;
  font-size: 1.0625rem;
  line-height: 1.8;
}

.information ol {
  margin-left: 24px;
  margin-bottom: 16px;
  color: var(--text-secondary);
}

.information ol li {
  margin-bottom: 8px;
  padding-left: 8px;
}

.information a {
  color: var(--primary-color);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.2s ease;
  display: inline-block;
  padding: 8px 16px;
  background: var(--bg-light);
  border-radius: 8px;
  margin-top: 8px;
}

.information a:hover {
  color: var(--primary-hover);
  background: #E0E7FF;
}

/* Feature Cards */
.feature-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
  margin: 32px 0;
}

.feature-card {
  background: var(--bg-light);
  padding: 28px;
  border-radius: 16px;
  border: 1px solid var(--border-color);
  transition: all 0.3s ease;
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--primary-color);
}

.feature-card h3 {
  color: var(--primary-color);
  margin-bottom: 12px;
  font-size: 1.25rem;
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 8px;
}

.feature-card h3::before {
  content: '✓';
  font-size: 1rem;
  background: var(--primary-color);
  color: white;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.feature-card p {
  color: var(--text-secondary);
  font-size: 0.9375rem;
  line-height: 1.6;
}

/* Stats Section */
.stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 24px;
  margin: 32px 0;
}

.stat-card {
  background: var(--bg-white);
  padding: 32px 24px;
  border-radius: 16px;
  text-align: center;
  box-shadow: var(--shadow-md);
  border: 1px solid var(--border-color);
  transition: all 0.3s ease;
}

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

.stat-card .number {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 8px;
  background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.stat-card .label {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  font-weight: 500;
}

/* Footer */
.footer {
  text-align: center;
  padding: 32px 20px;
  color: var(--text-secondary);
  font-size: 0.9375rem;
  font-weight: 400;
}

/* Responsive Design */
@media (max-width: 768px) {
  body {
    padding: 12px;
  }

  .hero-section h1 {
    font-size: 1.875rem;
  }

  .hero-section .subtitle {
    font-size: 1rem;
  }

  .login-panel {
    padding: 32px 24px;
  }

  .login-panel h2 {
    font-size: 1.5rem;
  }

  .information {
    padding: 32px 24px;
  }

  .information h1 {
    font-size: 1.75rem;
  }

  .information h2 {
    font-size: 1.25rem;
  }

  .btn-primary {
    padding: 14px 32px;
    font-size: 1rem;
    width: 100%;
  }

  .feature-cards {
    grid-template-columns: 1fr;
  }

  .stats {
    grid-template-columns: 1fr;
  }

  .stat-card .number {
    font-size: 2rem;
  }
}

@media (max-width: 480px) {
  .hero-section h1 {
    font-size: 1.5rem;
  }

  .login-panel {
    padding: 24px 16px;
  }

  .information {
    padding: 24px 16px;
  }

  .information h1 {
    font-size: 1.5rem;
  }

  .information h2 {
    font-size: 1.125rem;
  }

  .information p,
  .information ol {
    font-size: 0.9375rem;
  }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* Loading Animation */
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.login-panel,
.information {
  animation: fadeIn 0.6s ease-out;
}

/* Error Message */
.error-message {
  background: #FEE2E2;
  color: #991B1B;
  padding: 12px 16px;
  border-radius: 8px;
  margin-top: 16px;
  border-left: 4px solid #DC2626;
  font-weight: 500;
}