:root {
  --bg-primary: #121212;
  --bg-secondary: #1a1a1a;
  --bg-card: #252525;
  --bg-card-hover: #2d2d2d;
  --text-primary: #ffffff;
  --text-secondary: #b0b0b0;
  --text-tertiary: #808080;
  --accent-purple: #8B7FC7;
  --accent-blue: #5B8DBF;
  --accent-mint: #7FCBA4;
  --accent-light-blue: #6BB6D6;
  --accent-yellow: #F5C45A;
  --accent-red: #E57373;
  --border-radius-sm: 8px;
  --border-radius-md: 12px;
  --border-radius-lg: 16px;
  --border-radius-xl: 24px;
  --shadow-glow: 0 0 40px rgba(139, 127, 199, 0.15);
  --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.3);
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --max-width: 960px;
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Hiragino Sans', 'Noto Sans JP', Roboto, sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  min-height: 100vh;
  overflow-x: hidden;
}

a {
  color: var(--accent-purple);
  text-decoration: none;
  transition: color var(--transition);
}

a:hover {
  color: var(--accent-light-blue);
}

img {
  max-width: 100%;
  height: auto;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(18, 18, 18, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(139, 127, 199, 0.1);
  transition: background var(--transition);
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.header-brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.header-brand svg {
  width: 36px;
  height: 36px;
  border-radius: 8px;
}

.header-brand span {
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text-primary);
}

.header-nav {
  display: flex;
  align-items: center;
  gap: 8px;
}

.lang-switch {
  display: inline-flex;
  background: var(--bg-card);
  border-radius: var(--border-radius-sm);
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.06);
}

.lang-switch a {
  padding: 6px 14px;
  font-size: 13px;
  font-weight: 600;
  color: var(--text-tertiary);
  transition: all var(--transition);
  letter-spacing: 0.02em;
}

.lang-switch a:hover {
  color: var(--text-primary);
  background: transparent;
}

.lang-switch a.active {
  color: var(--text-primary);
  background: var(--accent-purple);
}

.hero {
  padding: 140px 0 80px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  left: 50%;
  transform: translateX(-50%);
  width: 800px;
  height: 800px;
  background: radial-gradient(circle, rgba(139, 127, 199, 0.08) 0%, transparent 70%);
  pointer-events: none;
}

.hero-icon {
  width: 120px;
  height: 120px;
  margin: 0 auto 32px;
  border-radius: 28px;
  box-shadow: var(--shadow-glow), var(--shadow-card);
  animation: float 6s ease-in-out infinite;
  position: relative;
  z-index: 1;
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-12px); }
}

.hero h1 {
  font-size: 42px;
  font-weight: 800;
  letter-spacing: -0.03em;
  margin-bottom: 8px;
  background: linear-gradient(135deg, var(--text-primary) 0%, var(--accent-purple) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  position: relative;
  z-index: 1;
}

.hero .tagline {
  font-size: 18px;
  color: var(--text-secondary);
  margin-bottom: 16px;
  position: relative;
  z-index: 1;
}

.hero .description {
  font-size: 15px;
  color: var(--text-tertiary);
  max-width: 520px;
  margin: 0 auto;
  line-height: 1.8;
  position: relative;
  z-index: 1;
}

.section {
  padding: 80px 0;
}

.section-title {
  font-size: 28px;
  font-weight: 700;
  text-align: center;
  margin-bottom: 12px;
  letter-spacing: -0.02em;
}

.section-subtitle {
  font-size: 15px;
  color: var(--text-secondary);
  text-align: center;
  margin-bottom: 48px;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.feature-card {
  background: var(--bg-card);
  border-radius: var(--border-radius-lg);
  padding: 32px 24px;
  border: 1px solid rgba(255, 255, 255, 0.04);
  border-left: 3px solid var(--card-accent, var(--accent-purple));
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}

.feature-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(135deg, rgba(139, 127, 199, 0.03) 0%, transparent 60%);
  pointer-events: none;
}

.feature-card:hover {
  background: var(--bg-card-hover);
  transform: translateY(-4px);
  box-shadow: var(--shadow-card);
}

.feature-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--border-radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  background: rgba(139, 127, 199, 0.1);
}

.feature-card:nth-child(1) { --card-accent: var(--accent-purple); }
.feature-card:nth-child(1) .feature-icon { background: rgba(139, 127, 199, 0.1); }
.feature-card:nth-child(1) .feature-icon svg { color: var(--accent-purple); }

.feature-card:nth-child(2) { --card-accent: var(--accent-blue); }
.feature-card:nth-child(2) .feature-icon { background: rgba(91, 141, 191, 0.1); }
.feature-card:nth-child(2) .feature-icon svg { color: var(--accent-blue); }

.feature-card:nth-child(3) { --card-accent: var(--accent-light-blue); }
.feature-card:nth-child(3) .feature-icon { background: rgba(107, 182, 214, 0.1); }
.feature-card:nth-child(3) .feature-icon svg { color: var(--accent-light-blue); }

.feature-card h3 {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text-primary);
}

.feature-card p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.7;
}

.howto-steps {
  display: flex;
  flex-direction: column;
  gap: 0;
  max-width: 640px;
  margin: 0 auto;
  position: relative;
}

.howto-steps::before {
  content: '';
  position: absolute;
  left: 28px;
  top: 28px;
  bottom: 28px;
  width: 2px;
  background: linear-gradient(to bottom, var(--accent-purple), var(--accent-blue), var(--accent-mint));
  border-radius: 1px;
}

.step {
  display: flex;
  align-items: flex-start;
  gap: 20px;
  padding: 24px 0;
  position: relative;
}

.step-number {
  width: 56px;
  height: 56px;
  min-width: 56px;
  border-radius: 50%;
  background: var(--bg-card);
  border: 2px solid var(--accent-purple);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  font-weight: 700;
  color: var(--accent-purple);
  z-index: 1;
}

.step:nth-child(2) .step-number {
  border-color: var(--accent-blue);
  color: var(--accent-blue);
}

.step:nth-child(3) .step-number {
  border-color: var(--accent-mint);
  color: var(--accent-mint);
}

.step-content h3 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 4px;
  padding-top: 14px;
}

.step-content p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.7;
}

.faq-list {
  max-width: 640px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.faq-item {
  background: var(--bg-card);
  border-radius: var(--border-radius-md);
  border: 1px solid rgba(255, 255, 255, 0.04);
  overflow: hidden;
  transition: all var(--transition);
}

.faq-question {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 24px;
  cursor: pointer;
  font-size: 15px;
  font-weight: 600;
  color: var(--text-primary);
  background: transparent;
  border: none;
  width: 100%;
  text-align: left;
  font-family: inherit;
  line-height: 1.5;
}

.faq-question:hover {
  color: var(--accent-purple);
}

.faq-toggle {
  width: 24px;
  height: 24px;
  min-width: 24px;
  color: var(--text-tertiary);
  transition: transform var(--transition);
}

.faq-item.open .faq-toggle {
  transform: rotate(45deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.faq-answer-inner {
  padding: 0 24px 20px;
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.8;
}

.faq-item.open .faq-answer {
  max-height: 300px;
}

.contact-section {
  text-align: center;
  padding: 80px 0;
}

.contact-section .section-title {
  margin-bottom: 12px;
}

.contact-section .section-subtitle {
  margin-bottom: 32px;
}

.contact-card {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  background: var(--bg-card);
  border: 1px solid rgba(139, 127, 199, 0.15);
  border-radius: var(--border-radius-md);
  padding: 16px 28px;
  transition: all var(--transition);
}

.contact-card:hover {
  border-color: var(--accent-purple);
  box-shadow: var(--shadow-glow);
  transform: translateY(-2px);
}

.contact-card svg {
  color: var(--accent-purple);
}

.contact-card a {
  font-size: 15px;
  font-weight: 500;
}

.footer {
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  padding: 40px 0;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
}

.footer-links {
  display: flex;
  gap: 24px;
}

.footer-links a {
  font-size: 13px;
  color: var(--text-tertiary);
}

.footer-links a:hover {
  color: var(--text-secondary);
}

.footer-copy {
  font-size: 13px;
  color: var(--text-tertiary);
}

.privacy-page {
  padding: 120px 0 80px;
  min-height: 60vh;
}

.privacy-page h1 {
  font-size: 28px;
  font-weight: 700;
  margin-bottom: 8px;
}

.privacy-page .effective-date {
  font-size: 14px;
  color: var(--text-tertiary);
  margin-bottom: 48px;
}

.policy-content {
  max-width: 720px;
  margin: 0 auto;
}

.policy-section {
  margin-bottom: 40px;
}

.policy-section h2 {
  font-size: 18px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

.policy-section h3 {
  font-size: 15px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 8px;
  margin-top: 20px;
}

.policy-section p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.9;
  margin-bottom: 12px;
}

.policy-section ul {
  list-style: none;
  padding: 0;
  margin-bottom: 12px;
}

.policy-section ul li {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.9;
  padding-left: 20px;
  position: relative;
  margin-bottom: 4px;
}

.policy-section ul li::before {
  content: '';
  position: absolute;
  left: 4px;
  top: 11px;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--accent-purple);
}

.policy-section a {
  color: var(--accent-purple);
  text-decoration: underline;
  text-decoration-color: rgba(139, 127, 199, 0.3);
  text-underline-offset: 2px;
}

.policy-section a:hover {
  text-decoration-color: var(--accent-purple);
}

.policy-section .highlight {
  background: rgba(139, 127, 199, 0.06);
  border-left: 3px solid var(--accent-purple);
  padding: 16px 20px;
  border-radius: 0 var(--border-radius-sm) var(--border-radius-sm) 0;
  margin: 16px 0;
}

.policy-section .highlight p {
  margin-bottom: 0;
  color: var(--text-secondary);
}

.privacy-icon {
  width: 48px;
  height: 48px;
  margin-bottom: 16px;
  color: var(--accent-purple);
}

@media (max-width: 768px) {
  .features-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .hero {
    padding: 120px 0 60px;
  }

  .hero h1 {
    font-size: 30px;
  }

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

  .hero-icon {
    width: 96px;
    height: 96px;
    border-radius: 22px;
  }

  .section {
    padding: 60px 0;
  }

  .section-title {
    font-size: 22px;
  }

  .footer-inner {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }

  .howto-steps::before {
    left: 27px;
  }
}

@media (max-width: 480px) {
  .hero h1 {
    font-size: 26px;
  }

  .header-brand span {
    font-size: 16px;
  }

  .container {
    padding: 0 16px;
  }

  .feature-card {
    padding: 24px 20px;
  }

  .step {
    gap: 16px;
  }

  .step-number {
    width: 48px;
    height: 48px;
    min-width: 48px;
    font-size: 16px;
  }

  .howto-steps::before {
    left: 23px;
  }
}

.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}