:root {
  /* Light Theme (Default) */
  --bg-primary: #ffffff;
  --bg-secondary: #f8f9fa;
  --bg-card: #ffffff;
  --text-primary: #1f2937;
  --text-secondary: #6b7280;
  --text-muted: #9ca3af;
  --primary: #6366f1;
  --primary-hover: #4f46e5;
  --accent: #8b5cf6;
  --accent-hover: #7c3aed;
  --border: #e5e7eb;
  --shadow: rgba(0, 0, 0, 0.1);
  --gradient-start: #6366f1;
  --gradient-end: #8b5cf6;
  --nav-bg: rgba(255, 255, 255, 0.95);
}

[data-theme="dark"] {
  --bg-primary: #0f172a;
  --bg-secondary: #1e293b;
  --bg-card: #1e293b;
  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --primary: #818cf8;
  --primary-hover: #a5b4fc;
  --accent: #a78bfa;
  --accent-hover: #c4b5fd;
  --border: #334155;
  --shadow: rgba(0, 0, 0, 0.3);
  --gradient-start: #818cf8;
  --gradient-end: #a78bfa;
  --nav-bg: rgba(15, 23, 42, 0.95);
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Noto Sans JP', 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  transition: background-color 0.3s ease, color 0.3s ease;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Header & Navigation */
header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: var(--nav-bg);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
  z-index: 1000;
  transition: background-color 0.3s ease, border-color 0.3s ease;
}

nav {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  text-decoration: none;
  transition: opacity 0.3s ease;
}

.logo:hover {
  opacity: 0.8;
}

.nav-links {
  display: flex;
  gap: 2rem;
  align-items: center;
  list-style: none;
}

.nav-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-weight: 500;
  position: relative;
  padding: 0.5rem 0;
  transition: color 0.3s ease;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
  transition: width 0.3s ease;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--primary);
}

.nav-links a:hover::after,
.nav-links a.active::after {
  width: 100%;
}

/* Theme Toggle Button */
.theme-toggle {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 50%;
  width: 40px;
  height: 40px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  transition: all 0.3s ease;
}

.theme-toggle:hover {
  background: var(--primary);
  border-color: var(--primary);
  transform: rotate(180deg);
}

.theme-toggle:hover .icon {
  filter: brightness(0) invert(1);
}

/* Main Content */
main {
  flex: 1;
  max-width: 1200px;
  margin: 0 auto;
  padding: 8rem 2rem 4rem;
  width: 100%;
}

/* Hero Section */
.hero {
  text-align: center;
  padding: 4rem 0;
  animation: fadeInUp 0.8s ease;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.hero-avatar {
  width: 150px;
  height: 150px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
  margin: 0 auto 2rem;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 4rem;
  color: white;
  box-shadow: 0 10px 40px var(--shadow);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.hero-avatar:hover {
  transform: scale(1.05);
  box-shadow: 0 15px 50px var(--shadow);
}

.avatar-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: 50%;
}

.hero h1 {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 1rem;
  background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero .subtitle {
  font-size: 1.25rem;
  color: var(--text-secondary);
  margin-bottom: 2rem;
}

.hero-description {
  max-width: 600px;
  margin: 0 auto 3rem;
  color: var(--text-secondary);
  font-size: 1.1rem;
}

/* Section Styles */
.section {
  padding: 3rem 0;
  animation: fadeInUp 0.8s ease;
}

.section-title {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 2rem;
  text-align: center;
  background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* Cards Grid */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 2rem;
  transition: all 0.3s ease;
  box-shadow: 0 4px 20px var(--shadow);
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 40px var(--shadow);
  border-color: var(--primary);
}

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

.card h3 {
  font-size: 1.25rem;
  margin-bottom: 0.75rem;
  color: var(--text-primary);
}

.card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.6;
}

.card-comment {
  margin-top: 1rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
  color: var(--text-muted);
  font-size: 0.9rem;
}

/* Coming Soon */
.coming-soon {
  text-align: center;
  padding: 6rem 2rem;
}

.coming-soon-icon {
  font-size: 5rem;
  margin-bottom: 2rem;
  animation: pulse 2s infinite;
}

@keyframes pulse {

  0%,
  100% {
    transform: scale(1);
  }

  50% {
    transform: scale(1.1);
  }
}

.coming-soon h2 {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.coming-soon p {
  color: var(--text-secondary);
  font-size: 1.1rem;
}

/* Social Links */
.social-links {
  display: flex;
  justify-content: center;
  gap: 1.5rem;
  margin-top: 2rem;
}

.social-link {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 50px;
  color: var(--text-primary);
  text-decoration: none;
  font-weight: 500;
  transition: all 0.3s ease;
}

.social-link:hover {
  background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
  border-color: transparent;
  color: white;
  transform: translateY(-3px);
  box-shadow: 0 5px 20px var(--shadow);
}

.social-link svg {
  width: 20px;
  height: 20px;
}

/* Footer */
footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border);
  padding: 3rem 2rem;
  text-align: center;
  transition: background-color 0.3s ease, border-color 0.3s ease;
}

.footer-content {
  max-width: 1200px;
  margin: 0 auto;
}

.footer-links {
  margin-bottom: 1.5rem;
}

.footer-text {
  color: var(--text-muted);
  font-size: 0.9rem;
}

/* Responsive */
@media (max-width: 768px) {
  nav {
    padding: 1rem;
  }

  .nav-links {
    gap: 1rem;
  }

  .nav-links a {
    font-size: 0.9rem;
  }

  main {
    padding: 6rem 1rem 2rem;
  }

  .hero h1 {
    font-size: 2rem;
  }

  .hero-avatar {
    width: 120px;
    height: 120px;
    font-size: 3rem;
  }

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

  .social-links {
    flex-direction: column;
    align-items: center;
  }
}

/* Mobile Navigation */
@media (max-width: 600px) {
  .nav-links {
    gap: 0.75rem;
    font-size: 0.85rem;
  }

  .logo {
    font-size: 1.2rem;
  }
}

/* Badge */
.badge {
  display: inline-block;
  padding: 0.25rem 0.75rem;
  background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
  color: white;
  font-size: 0.75rem;
  font-weight: 600;
  border-radius: 50px;
  margin-bottom: 0.5rem;
}