:root {
  --primary: #4A90D9;
  --primary-dark: #3A7BC8;
  --primary-light: #E8F0FA;
  --bg-light: #F0F4F8;
  --bg-white: #FFFFFF;
  --text-dark: #1A1A2E;
  --text-gray: #6B7280;
  --text-light: #9CA3AF;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
  --radius: 12px;
  --transition: all 0.3s ease;
}

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

html {
  scroll-behavior: smooth;
}

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

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

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

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

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: 50px;
  font-weight: 600;
  font-size: 16px;
  transition: var(--transition);
  cursor: pointer;
  border: none;
}

.btn-primary {
  background: var(--primary);
  color: white;
  box-shadow: var(--shadow);
}

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

.btn-secondary {
  background: white;
  color: var(--primary);
  border: 2px solid var(--primary);
}

.btn-secondary:hover {
  background: var(--primary-light);
}

.lang-switch {
  display: flex;
  gap: 4px;
  background: white;
  padding: 4px;
  border-radius: 8px;
  box-shadow: var(--shadow-sm);
}

.lang-switch a {
  padding: 6px 16px;
  border-radius: 6px;
  font-size: 14px;
  font-weight: 500;
  color: var(--text-gray);
}

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

.lang-switch a:not(.active):hover {
  color: var(--primary);
  background: var(--primary-light);
}

header {
  background: white;
  box-shadow: var(--shadow-sm);
  position: sticky;
  top: 0;
  z-index: 100;
}

header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px 20px;
}

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

.logo img {
  width: 44px;
  height: 44px;
}

.logo-text h1 {
  font-size: 20px;
  font-weight: 700;
  color: var(--text-dark);
}

.logo-text p {
  font-size: 12px;
  color: var(--text-gray);
}

.hero {
  padding: 80px 20px;
  text-align: center;
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  color: white;
}

.hero h1 {
  font-size: clamp(28px, 5vw, 48px);
  font-weight: 700;
  margin-bottom: 16px;
}

.hero p {
  font-size: clamp(16px, 2vw, 20px);
  opacity: 0.95;
  margin-bottom: 32px;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.hero-icon {
  width: 120px;
  height: 120px;
  background: rgba(255, 255, 255, 0.2);
  border-radius: 60px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 24px;
}

.hero-icon svg {
  width: 60px;
  height: 60px;
}

.section {
  padding: 80px 20px;
}

.section h2 {
  font-size: clamp(24px, 4vw, 36px);
  font-weight: 700;
  text-align: center;
  margin-bottom: 16px;
}

.section-subtitle {
  text-align: center;
  color: var(--text-gray);
  font-size: 16px;
  margin-bottom: 48px;
}

.features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
  max-width: 1200px;
  margin: 0 auto;
}

.feature-card {
  background: white;
  padding: 32px;
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

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

.feature-icon {
  width: 56px;
  height: 56px;
  background: var(--primary-light);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
}

.feature-icon svg {
  width: 28px;
  height: 28px;
  color: var(--primary);
}

.feature-card h3 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text-dark);
}

.feature-card p {
  color: var(--text-gray);
  font-size: 14px;
}

.how-to {
  max-width: 900px;
  margin: 0 auto;
}

.step {
  display: flex;
  gap: 20px;
  margin-bottom: 32px;
}

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

.step-number {
  width: 48px;
  height: 48px;
  background: var(--primary);
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  font-weight: 700;
  flex-shrink: 0;
}

.step-content h3 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text-dark);
}

.step-content p {
  color: var(--text-gray);
}

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

.faq-item {
  background: white;
  padding: 24px;
  border-radius: var(--radius);
  margin-bottom: 16px;
  box-shadow: var(--shadow-sm);
}

.faq-item h3 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text-dark);
}

.faq-item p {
  color: var(--text-gray);
  font-size: 14px;
}

footer {
  background: var(--text-dark);
  color: white;
  padding: 48px 20px;
}

footer .container {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 40px;
}

footer h3 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 16px;
}

footer a {
  color: rgba(255, 255, 255, 0.8);
  display: block;
  margin-bottom: 8px;
  font-size: 14px;
}

footer a:hover {
  color: white;
}

footer .contact {
  color: rgba(255, 255, 255, 0.8);
  font-size: 14px;
}

footer .bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  margin-top: 32px;
  padding-top: 24px;
  text-align: center;
  color: rgba(255, 255, 255, 0.6);
  font-size: 12px;
}

@media (max-width: 768px) {
  .hero {
    padding: 60px 20px;
  }

  .section {
    padding: 60px 20px;
  }

  header .container {
    padding: 12px 16px;
  }

  .logo img {
    width: 36px;
    height: 36px;
  }

  .logo-text h1 {
    font-size: 16px;
  }

  .logo-text p {
    font-size: 10px;
  }

  .step {
    flex-direction: column;
  }
}