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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  color: #333;
  line-height: 1.6;
}

.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 2rem;
  background: #1a1a2e;
  color: #fff;
  position: sticky;
  top: 0;
  z-index: 100;
}

.logo {
  font-size: 1.4rem;
  font-weight: bold;
}

.nav-links {
  display: flex;
  list-style: none;
  gap: 1.5rem;
}

.nav-links a {
  color: #e0e0e0;
  text-decoration: none;
  transition: color 0.2s;
}

.nav-links a:hover {
  color: #6c63ff;
}

.hero {
  text-align: center;
  padding: 5rem 2rem;
  background: linear-gradient(135deg, #1a1a2e, #16213e);
  color: #fff;
}

.hero h1 {
  font-size: 2.5rem;
  margin-bottom: 0.5rem;
}

.hero p {
  font-size: 1.2rem;
  color: #ccc;
  margin-bottom: 2rem;
}

.btn {
  padding: 0.8rem 1.8rem;
  font-size: 1rem;
  border: none;
  border-radius: 8px;
  background: #6c63ff;
  color: #fff;
  cursor: pointer;
  transition: background 0.2s, transform 0.1s;
}

.btn:hover {
  background: #5a52d5;
}

.btn:active {
  transform: scale(0.97);
}

#dog-container {
  margin-top: 1.5rem;
}

#dog-container img {
  max-width: 300px;
  border-radius: 12px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

.section {
  padding: 4rem 2rem;
  max-width: 900px;
  margin: 0 auto;
  text-align: center;
}

.section h2 {
  font-size: 1.8rem;
  margin-bottom: 1rem;
}

.alt {
  max-width: 100%;
  background: #f5f5f5;
}

.cards {
  display: flex;
  gap: 1.5rem;
  justify-content: center;
  flex-wrap: wrap;
  max-width: 900px;
  margin: 0 auto;
}

.card {
  background: #fff;
  padding: 2rem;
  border-radius: 12px;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.08);
  flex: 1;
  min-width: 220px;
  max-width: 280px;
}

.card h3 {
  font-size: 1.3rem;
  margin-bottom: 0.5rem;
}

.footer {
  text-align: center;
  padding: 2rem;
  background: #1a1a2e;
  color: #aaa;
}

/* Hamburger menu button (hidden on desktop) */
.menu-toggle {
  display: none;
  background: none;
  border: 1px solid #444;
  border-radius: 4px;
  color: #fff;
  font-size: 1.5rem;
  cursor: pointer;
  padding: 0.2rem 0.6rem;
  margin-left: auto;
  line-height: 1;
}

/* RWD */
@media (max-width: 768px) {
  .navbar {
    padding: 0.8rem 1.2rem;
  }

  .menu-toggle {
    display: block;
  }

  .navbar {
    flex-wrap: wrap;
  }

  .nav-links {
    display: none;
    flex-direction: column;
    width: 100%;
    background: #1a1a2e;
    padding: 0.8rem 0;
    gap: 0.5rem;
    order: 3;
  }

  .nav-links.open {
    display: flex;
  }

  .nav-links li {
    list-style: none;
    border-top: 1px solid #2a2a4e;
  }

  .nav-links a {
    display: block;
    padding: 0.6rem 0;
  }

  .hero {
    padding: 3rem 1.2rem;
  }

  .hero h1 {
    font-size: 1.8rem;
  }

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

  .btn {
    padding: 0.7rem 1.4rem;
    font-size: 0.9rem;
  }

  #dog-container img {
    max-width: 90%;
  }

  .section {
    padding: 2.5rem 1.2rem;
  }

  .section h2 {
    font-size: 1.4rem;
  }

  .cards {
    flex-direction: column;
    align-items: stretch;
    padding: 0 0.5rem;
  }

  .card {
    max-width: 100%;
  }

  .card h3 {
    font-size: 1.1rem;
  }

  .footer {
    padding: 1.5rem 1rem;
    font-size: 0.9rem;
  }
}