/* ===== Reset & Base Styles ===== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  /* Colors */
  --primary: #6366F1;
  --primary-dark: #4F46E5;
  --secondary: #8B5CF6;
  --accent: #EC4899;
  --text-primary: #1F2937;
  --text-secondary: #6B7280;
  --text-light: #9CA3AF;
  --bg-white: #FFFFFF;
  --bg-gray: #F9FAFB;
  --bg-dark: #111827;
  --border: #E5E7EB;

  /* Spacing */
  --container-padding: 1.5rem;
  --section-padding: 5rem 0;

  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-ja: 'Noto Sans JP', sans-serif;

  /* Shadows */
  --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);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);

  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-full: 9999px;

  /* Transitions */
  --transition: all 0.2s ease;
}

body {
  font-family: var(--font-ja), var(--font-sans);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

html {
  scroll-behavior: smooth;
}

a {
  text-decoration: none;
  color: inherit;
}

/* ===== Container ===== */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--container-padding);
}

/* ===== Header ===== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
  padding: 1rem 0;
}

.header-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
}

.logo-text {
  color: var(--text-primary);
}

.logo-ai {
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav {
  display: flex;
  align-items: center;
  gap: 2rem;
}

.nav-link {
  color: var(--text-secondary);
  font-weight: 500;
  transition: var(--transition);
}

.nav-link:hover {
  color: var(--primary);
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  transition: var(--transition);
  cursor: pointer;
  border: none;
  font-family: inherit;
  font-size: 1rem;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  color: white;
  box-shadow: var(--shadow);
}

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

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

.btn-secondary:hover {
  border-color: var(--primary);
  color: var(--primary);
}

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

.btn-outline:hover {
  background: var(--primary);
  color: white;
}

.btn-sm {
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
}

.btn-lg {
  padding: 1rem 2rem;
  font-size: 1.125rem;
}

/* ===== Hero Section ===== */
.hero {
  padding: 8rem 0 6rem;
  background: linear-gradient(180deg, var(--bg-gray) 0%, var(--bg-white) 100%);
  overflow: hidden;
}

.hero-content {
  text-align: center;
  position: relative;
  z-index: 2;
}

.hero-badge {
  margin-bottom: 1.5rem;
}

.badge {
  display: inline-block;
  padding: 0.5rem 1rem;
  background: white;
  border-radius: var(--radius-full);
  font-size: 0.875rem;
  font-weight: 600;
  box-shadow: var(--shadow-sm);
}

.hero-title {
  font-size: clamp(2.5rem, 5vw, 4rem);
  font-weight: 900;
  line-height: 1.2;
  margin-bottom: 1.5rem;
  letter-spacing: -0.02em;
}

.gradient-text {
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 50%, var(--accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-description {
  font-size: 1.25rem;
  color: var(--text-secondary);
  max-width: 700px;
  margin: 0 auto 2.5rem;
}

.hero-cta {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 4rem;
}

.hero-stats {
  display: flex;
  gap: 4rem;
  justify-content: center;
  flex-wrap: wrap;
  padding: 2rem 0;
}

.stat {
  text-align: center;
}

.stat-value {
  font-size: 2.5rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.stat-label {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-top: 0.25rem;
}

.hero-visual {
  margin-top: 4rem;
  display: flex;
  gap: 1.5rem;
  justify-content: center;
  flex-wrap: wrap;
}

.hero-card {
  width: 200px;
  height: 120px;
  background: white;
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  animation: float 3s ease-in-out infinite;
}

.hero-card.card-1 {
  animation-delay: 0s;
}

.hero-card.card-2 {
  animation-delay: 0.5s;
}

.hero-card.card-3 {
  animation-delay: 1s;
}

@keyframes float {
  0%, 100% {
    transform: translateY(0px);
  }
  50% {
    transform: translateY(-20px);
  }
}

.card-placeholder {
  text-align: center;
}

.card-icon {
  font-size: 2rem;
  display: block;
  margin-bottom: 0.5rem;
}

.card-text {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-secondary);
}

/* ===== Section Styles ===== */
section {
  padding: var(--section-padding);
}

.section-header {
  text-align: center;
  margin-bottom: 4rem;
}

.section-title {
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 800;
  margin-bottom: 1rem;
}

.section-description {
  font-size: 1.125rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto;
}

/* ===== Features Section ===== */
.features {
  background: var(--bg-white);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
}

.feature-card {
  padding: 2rem;
  background: var(--bg-gray);
  border-radius: var(--radius-xl);
  transition: var(--transition);
}

.feature-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-xl);
}

.feature-icon {
  margin-bottom: 1.5rem;
}

.feature-title {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 1rem;
}

.feature-description {
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ===== How It Works Section ===== */
.how-it-works {
  background: var(--bg-gray);
}

.steps {
  display: flex;
  gap: 2rem;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
}

.step {
  flex: 1;
  min-width: 250px;
  max-width: 300px;
  padding: 2rem;
  background: white;
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow);
}

.step-number {
  display: inline-block;
  width: 60px;
  height: 60px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  font-weight: 800;
  margin-bottom: 1.5rem;
}

.step-title {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
}

.step-description {
  color: var(--text-secondary);
  line-height: 1.7;
  font-size: 0.9375rem;
}

.step-arrow {
  font-size: 2rem;
  color: var(--primary);
  font-weight: 700;
}

/* ===== Pricing Section ===== */
.pricing {
  background: var(--bg-white);
}

.pricing-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  max-width: 1000px;
  margin: 0 auto;
}

.pricing-card {
  padding: 2.5rem;
  background: white;
  border: 2px solid var(--border);
  border-radius: var(--radius-xl);
  position: relative;
  transition: var(--transition);
}

.pricing-card:hover {
  border-color: var(--primary);
  box-shadow: var(--shadow-xl);
}

.pricing-card-featured {
  background: linear-gradient(180deg, var(--bg-gray) 0%, white 100%);
  border-color: var(--primary);
  box-shadow: var(--shadow-lg);
}

.pricing-badge {
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  color: white;
  padding: 0.375rem 1rem;
  border-radius: var(--radius-full);
  font-size: 0.875rem;
  font-weight: 600;
}

.pricing-header {
  text-align: center;
  margin-bottom: 2rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--border);
}

.pricing-title {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 1rem;
}

.pricing-price {
  display: flex;
  align-items: baseline;
  justify-content: center;
  gap: 0.25rem;
}

.price-amount {
  font-size: 3rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.price-period {
  color: var(--text-secondary);
  font-size: 1rem;
}

.pricing-features {
  list-style: none;
  margin-bottom: 2rem;
}

.pricing-feature {
  padding: 0.75rem 0;
  color: var(--text-secondary);
  border-bottom: 1px solid var(--border);
}

.pricing-feature:last-child {
  border-bottom: none;
}

/* ===== Signup Section ===== */
.signup {
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  color: white;
}

.signup-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: start;
}

.signup-title {
  font-size: 2.5rem;
  font-weight: 800;
  margin-bottom: 1rem;
}

.signup-description {
  font-size: 1.125rem;
  opacity: 0.9;
  margin-bottom: 2rem;
}

.signup-benefits {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.benefit {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  background: rgba(255, 255, 255, 0.1);
  padding: 1rem;
  border-radius: var(--radius);
}

.benefit svg {
  flex-shrink: 0;
}

.signup-form-container {
  background: white;
  padding: 2rem;
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-xl);
}

.form-placeholder {
  text-align: center;
  padding: 2rem;
  color: var(--text-secondary);
}

.form-placeholder-text {
  margin-bottom: 1.5rem;
  line-height: 1.7;
}

.form-code {
  display: block;
  background: var(--bg-gray);
  padding: 1rem;
  border-radius: var(--radius);
  font-family: 'Monaco', 'Courier New', monospace;
  font-size: 0.875rem;
  text-align: left;
  margin: 1.5rem 0;
  color: var(--text-primary);
  overflow-x: auto;
}

.form-note {
  font-size: 0.875rem;
  color: var(--text-light);
  margin-top: 1rem;
}

/* ===== Footer ===== */
.footer {
  background: var(--bg-dark);
  color: white;
  padding: 4rem 0 2rem;
}

.footer-content {
  display: flex;
  flex-direction: column;
  gap: 3rem;
}

.footer-main {
  display: grid;
  grid-template-columns: 2fr 3fr;
  gap: 4rem;
}

.footer-brand {
  max-width: 300px;
}

.footer-description {
  color: rgba(255, 255, 255, 0.7);
  margin-top: 1rem;
  line-height: 1.7;
}

.footer-links {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 2rem;
}

.footer-heading {
  font-size: 0.875rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 1rem;
  color: rgba(255, 255, 255, 0.5);
}

.footer-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.footer-link {
  color: rgba(255, 255, 255, 0.7);
  transition: var(--transition);
}

.footer-link:hover {
  color: white;
}

.footer-bottom {
  padding-top: 2rem;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  text-align: center;
}

.footer-copyright {
  color: rgba(255, 255, 255, 0.5);
  font-size: 0.875rem;
}

/* ===== Responsive Design ===== */
@media (max-width: 768px) {
  .nav {
    display: none;
  }

  .hero {
    padding: 6rem 0 4rem;
  }

  .hero-title {
    font-size: 2rem;
  }

  .hero-description {
    font-size: 1rem;
  }

  .hero-stats {
    gap: 2rem;
  }

  .hero-card {
    width: 150px;
    height: 100px;
  }

  .steps {
    flex-direction: column;
  }

  .step-arrow {
    transform: rotate(90deg);
  }

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

  .signup-content {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .footer-main {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .footer-links {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 480px) {
  .hero-cta {
    flex-direction: column;
    align-items: stretch;
  }

  .btn-lg {
    width: 100%;
    justify-content: center;
  }
}