/* 
COLOR PALETTE
PRIMARY – 信頼・テクノロジー: #0070F3 (Blue 600)
SECONDARY – パネル・タグ: #64B5F6 (Blue 300)
ACCENT – Copy ボタン・アラート: #F50057 (Pink A400)
背景/文字色:
--bg-light: #FAFAFA; --txt-light: #212121;
--bg-dark: #0D1117; --txt-dark: #E0E0E0;
*/

:root {
  --color-primary: #0070F3;
  --color-secondary: #64B5F6;
  --color-accent: #F50057;
  --bg-light: #FAFAFA;
  --txt-light: #212121;
  --bg-dark: #0D1117;
  --txt-dark: #E0E0E0;
  --border-light: #E5E5E5;
  --border-dark: #30363D;
  --card-light: #FFFFFF;
  --card-dark: #161B22;
  --shadow: 0 2px 8px rgba(0,0,0,0.1);
  --radius: 8px;
  --transition: all 0.2s ease;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  line-height: 1.6;
  background: var(--bg-light);
  color: var(--txt-light);
  transition: var(--transition);
}

body.dark {
  background: var(--bg-dark);
  color: var(--txt-dark);
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1rem;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Header */
.header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 0;
  border-bottom: 1px solid var(--border-light);
  margin-bottom: 2rem;
}

body.dark .header {
  border-bottom-color: var(--border-dark);
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-primary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.logo-icon {
  font-size: 1.8rem;
}

.nav {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.language-select {
  padding: 0.5rem;
  border: 1px solid var(--border-light);
  border-radius: var(--radius);
  background: var(--card-light);
  color: var(--txt-light);
  font-size: 0.9rem;
  cursor: pointer;
  transition: var(--transition);
}

body.dark .language-select {
  border-color: var(--border-dark);
  background: var(--card-dark);
  color: var(--txt-dark);
}

.theme-toggle {
  padding: 0.5rem;
  border: 1px solid var(--border-light);
  border-radius: var(--radius);
  background: var(--card-light);
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
}

body.dark .theme-toggle {
  border-color: var(--border-dark);
  background: var(--card-dark);
}

.theme-icon {
  font-size: 1.2rem;
}

/* Main Content */
.main {
  flex: 1;
}

/* Hero Section */
.hero {
  text-align: center;
  margin-bottom: 3rem;
}

.hero-title {
  font-size: clamp(1.8rem, 4vw, 2.5rem);
  font-weight: 700;
  margin-bottom: 1rem;
  color: var(--color-primary);
}

.hero-subtitle {
  font-size: 1.1rem;
  color: var(--txt-light);
  opacity: 0.8;
  max-width: 600px;
  margin: 0 auto;
}

body.dark .hero-subtitle {
  color: var(--txt-dark);
}

/* Converter */
.converter {
  max-width: 800px;
  margin: 0 auto;
}

.step {
  background: var(--card-light);
  border: 1px solid var(--border-light);
  border-radius: var(--radius);
  padding: 1.5rem;
  margin-bottom: 1.5rem;
  box-shadow: var(--shadow);
  transition: var(--transition);
}

body.dark .step {
  background: var(--card-dark);
  border-color: var(--border-dark);
}

.step-header {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1rem;
}

.step-number {
  background: var(--color-primary);
  color: white;
  width: 2rem;
  height: 2rem;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  font-size: 0.9rem;
}

.step-title {
  font-size: 1.2rem;
  font-weight: 600;
}

/* Form Elements */
.input-group {
  margin-bottom: 1rem;
}

.label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: 500;
  color: var(--txt-light);
}

body.dark .label {
  color: var(--txt-dark);
}

.textarea {
  width: 100%;
  padding: 0.75rem;
  border: 2px solid var(--border-light);
  border-radius: var(--radius);
  background: var(--card-light);
  color: var(--txt-light);
  font-family: 'Consolas', 'Monaco', 'Courier New', monospace;
  font-size: 0.9rem;
  resize: vertical;
  min-height: 120px;
  transition: var(--transition);
}

.textarea:focus {
  outline: none;
  border-color: var(--color-primary);
}

body.dark .textarea {
  background: var(--card-dark);
  border-color: var(--border-dark);
  color: var(--txt-dark);
}

.help-text {
  color: var(--txt-light);
  opacity: 0.7;
  font-size: 0.85rem;
  margin-top: 0.5rem;
}

body.dark .help-text {
  color: var(--txt-dark);
}

/* Sample Buttons */
.sample-buttons {
  margin-top: 0.5rem;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
}

.sample-btn {
  padding: 0.25rem 0.5rem;
  background: var(--color-secondary);
  color: white;
  border: none;
  border-radius: 4px;
  font-size: 0.75rem;
  cursor: pointer;
  transition: var(--transition);
}

.sample-btn:hover {
  background: var(--color-primary);
  transform: translateY(-1px);
}

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

/* Radio Group */
.radio-group {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.radio-label {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.75rem;
  border: 2px solid var(--border-light);
  border-radius: var(--radius);
  cursor: pointer;
  transition: var(--transition);
}

.radio-label:hover {
  border-color: var(--color-secondary);
}

.radio-label:has(.radio:checked) {
  border-color: var(--color-primary);
  background: rgba(0, 112, 243, 0.05);
}

body.dark .radio-label {
  border-color: var(--border-dark);
}

body.dark .radio-label:has(.radio:checked) {
  background: rgba(0, 112, 243, 0.1);
}

.radio {
  accent-color: var(--color-primary);
}

.radio-text {
  flex: 1;
}

.radio-text strong {
  display: block;
  margin-bottom: 0.25rem;
}

.radio-text small {
  color: var(--txt-light);
  opacity: 0.7;
}

body.dark .radio-text small {
  color: var(--txt-dark);
}

/* Buttons */
.convert-btn {
  width: 100%;
  padding: 1rem 2rem;
  background: var(--color-primary);
  color: white;
  border: none;
  border-radius: var(--radius);
  font-size: 1.1rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
}

.convert-btn:hover {
  background: #0060D8;
  transform: translateY(-1px);
}

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

/* Output Section */
.output-section {
  background: var(--card-light);
  border: 1px solid var(--border-light);
  border-radius: var(--radius);
  padding: 1.5rem;
  margin-top: 2rem;
  box-shadow: var(--shadow);
}

body.dark .output-section {
  background: var(--card-dark);
  border-color: var(--border-dark);
}

.output-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
}

.output-title {
  font-size: 1.1rem;
  font-weight: 600;
}

.copy-btn {
  padding: 0.5rem 1rem;
  background: var(--color-accent);
  color: white;
  border: none;
  border-radius: var(--radius);
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
}

.copy-btn:hover {
  background: #E50044;
}

.code-output {
  background: #1E1E1E;
  color: #D4D4D4;
  padding: 1rem;
  border-radius: var(--radius);
  font-family: 'Consolas', 'Monaco', 'Courier New', monospace;
  font-size: 0.9rem;
  line-height: 1.5;
  overflow-x: auto;
  white-space: pre-wrap;
  word-break: break-word;
}

.copy-success {
  background: #10B981;
  color: white;
  padding: 0.5rem;
  border-radius: var(--radius);
  text-align: center;
  margin-top: 1rem;
  font-weight: 500;
}

/* Features Section */
.features {
  margin: 4rem 0;
  text-align: center;
}

.features-title {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 2rem;
  color: var(--color-primary);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
  margin-top: 2rem;
}

.feature {
  background: var(--card-light);
  border: 1px solid var(--border-light);
  border-radius: var(--radius);
  padding: 2rem 1.5rem;
  box-shadow: var(--shadow);
  transition: var(--transition);
}

.feature:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 16px rgba(0,0,0,0.15);
}

body.dark .feature {
  background: var(--card-dark);
  border-color: var(--border-dark);
}

.feature-icon {
  font-size: 2.5rem;
  margin-bottom: 1rem;
}

.feature-title {
  font-size: 1.2rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.feature-text {
  color: var(--txt-light);
  opacity: 0.8;
}

body.dark .feature-text {
  color: var(--txt-dark);
}

/* Footer */
.footer {
  margin-top: auto;
  border-top: 1px solid var(--border-light);
  padding: 2rem 0;
  text-align: center;
  color: var(--txt-light);
  opacity: 0.8;
  font-size: 0.9rem;
}

body.dark .footer {
  border-top-color: var(--border-dark);
  color: var(--txt-dark);
}

.footer-content {
  max-width: 800px;
  margin: 0 auto;
}

.legal-section {
  margin: 1rem 0;
  text-align: left;
}

.legal-title {
  font-weight: 600;
  cursor: pointer;
  padding: 0.5rem;
  border-radius: var(--radius);
  background: var(--card-light);
  border: 1px solid var(--border-light);
  margin-bottom: 0.5rem;
}

body.dark .legal-title {
  background: var(--card-dark);
  border-color: var(--border-dark);
}

.legal-content {
  padding: 1rem;
  border: 1px solid var(--border-light);
  border-radius: var(--radius);
  background: var(--card-light);
  margin-bottom: 1rem;
}

body.dark .legal-content {
  background: var(--card-dark);
  border-color: var(--border-dark);
}

.legal-content p {
  margin-bottom: 1rem;
}

.contact-section {
  margin-top: 2rem;
  padding: 1rem;
  background: var(--card-light);
  border: 1px solid var(--border-light);
  border-radius: var(--radius);
}

body.dark .contact-section {
  background: var(--card-dark);
  border-color: var(--border-dark);
}

.contact-section a {
  color: var(--color-primary);
  text-decoration: none;
}

.contact-section a:hover {
  text-decoration: underline;
}

/* Responsive Design */
@media (max-width: 768px) {
  .container {
    padding: 0 0.75rem;
  }
  
  .header {
    flex-direction: column;
    gap: 1rem;
    text-align: center;
  }
  
  .nav {
    justify-content: center;
  }
  
  .step {
    padding: 1rem;
  }
  
  .step-header {
    flex-direction: column;
    text-align: center;
    gap: 0.5rem;
  }
  
  .output-header {
    flex-direction: column;
    gap: 1rem;
  }
  
  .features-grid {
    grid-template-columns: 1fr;
  }
  
  .radio-group {
    gap: 0.5rem;
  }
  
  .radio-label {
    padding: 0.5rem;
  }
}

@media (max-width: 480px) {
  html {
    font-size: 14px;
  }
  
  .step {
    margin-bottom: 1rem;
  }
  
  .hero-title {
    font-size: 1.5rem;
  }
  
  .hero-subtitle {
    font-size: 1rem;
  }
}

/* Related Sites Section */
.related-sites-section {
  margin-bottom: 2rem;
  padding: 1.5rem 0;
  border-bottom: 1px solid var(--border-light);
}

body.dark .related-sites-section {
  border-bottom-color: var(--border-dark);
}

.related-sites-section h3 {
  color: var(--color-primary);
  margin-bottom: 1rem;
  font-size: 1.25rem;
  text-align: center;
}

.related-sites-section p {
  color: var(--txt-light);
  opacity: 0.8;
  margin-bottom: 1.5rem;
  text-align: center;
  font-size: 0.9rem;
}

body.dark .related-sites-section p {
  color: var(--txt-dark);
}

.sites-categories {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.5rem;
}

.category {
  background: var(--card-light);
  border: 1px solid var(--border-light);
  border-radius: var(--radius);
  padding: 1rem;
  transition: var(--transition);
}

body.dark .category {
  background: var(--card-dark);
  border-color: var(--border-dark);
}

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

.category h4 {
  color: var(--color-primary);
  margin-bottom: 0.75rem;
  font-size: 1rem;
  font-weight: 600;
  border-bottom: 1px solid var(--border-light);
  padding-bottom: 0.5rem;
}

body.dark .category h4 {
  border-bottom-color: var(--border-dark);
}

.sites-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.sites-list li {
  margin-bottom: 0.5rem;
}

.sites-list a {
  color: var(--color-primary);
  text-decoration: none;
  font-size: 0.9rem;
  transition: var(--transition);
  display: block;
  padding: 0.25rem 0;
}

.sites-list a:hover {
  color: #0060D8;
  text-decoration: underline;
  transform: translateX(4px);
}

.current-site {
  color: #10B981;
  font-weight: 500;
  font-size: 0.9rem;
  display: block;
  padding: 0.25rem 0;
}

/* モバイル対応 */
@media (max-width: 768px) {
  .sites-categories {
    grid-template-columns: 1fr;
    gap: 1rem;
  }

  .category {
    padding: 0.75rem;
  }

  .related-sites-section {
    padding: 1rem 0;
  }
}