@keyframes subtleMove {
  0% { background-position: 0 0; }
  100% { background-position: 80px 80px; }
}

@keyframes fadeInDown {
  from { opacity: 0; transform: translateY(-20px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeIn {
  to { opacity: 1; }
}

#seien-top {
  background: #f8fafc;
  color: #2d3748;
}

#seien-top .container {
  width: min(1200px, 94vw);
  margin: 0 auto;
}

#seien-top h1,
#seien-top h2,
#seien-top h3 {
  font-weight: 700;
  color: #1a202c;
  margin: 0 0 0.8rem;
}

#seien-top p {
  margin: 0 0 1rem;
}

#seien-top .hero-section {
  background: linear-gradient(rgba(0,0,0,0.7), rgba(0,0,0,0.7)), url('https://via.placeholder.com/1920x600') center/cover no-repeat;
  padding: 6rem 1rem;
  text-align: center;
  position: relative;
  overflow: hidden;
}

#seien-top .hero-section::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(26,32,44,0.1) 0%, rgba(74,144,226,0.1) 100%), url('data:image/svg+xml,%3Csvg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 80 80" width="80" height="80"%3E%3Ccircle cx="40" cy="40" r="1" fill="%234a90e2" fill-opacity="0.2"/%3E%3C/svg%3E') repeat;
  animation: subtleMove 25s linear infinite;
}

#seien-top .hero-section .content {
  max-width: 800px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

#seien-top .hero-section h1 {
  font-size: clamp(2.2rem, 4vw, 3rem);
  color: #fff;
  animation: fadeInDown 1s ease-out;
}

#seien-top .hero-section p {
  font-size: clamp(1.1rem, 2vw, 1.4rem);
  color: #f8fafc;
  animation: fadeInDown 1s ease-out 0.3s;
  animation-fill-mode: both;
}

#seien-top .mission-section {
  max-width: 1000px;
  margin: 4rem auto;
  padding: 3rem 1rem;
  text-align: center;
  background: #fff;
  border-radius: 12px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}

#seien-top .mission-section h2,
#seien-top .services-section h2,
#seien-top .about-section h2 {
  font-size: 2rem;
  position: relative;
}

#seien-top .mission-section h2::after,
#seien-top .services-section h2::after,
#seien-top .about-section h2::after {
  content: "";
  display: block;
  width: 40px;
  height: 2px;
  background: #4a90e2;
  margin: 0.5rem auto 0;
}

#seien-top .mission-section p {
  font-size: 1.1rem;
}

#seien-top .about-section {
  max-width: 1000px;
  margin: 4rem auto;
  padding: 0 1rem;
}

#seien-top .about-section p {
  font-size: 1.05rem;
  text-align: center;
}

#seien-top .about-section table {
  width: 100%;
  border-collapse: collapse;
  background: #fff;
  border-radius: 12px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.05);
  font-size: 1rem;
  color: #2d3748;
  overflow: hidden;
}

#seien-top .about-section th,
#seien-top .about-section td {
  padding: 1rem;
  border: 1px solid #edf2f7;
  text-align: left;
}

#seien-top .about-section th {
  background: #1a202c;
  color: #fff;
  font-weight: 500;
}

#seien-top .about-section td {
  background: #edf2f7;
}

#seien-top .about-section tr {
  transition: background 0.3s;
}

#seien-top .about-section tr:hover td {
  background: #dbe9fe;
}

#seien-top .services-section {
  max-width: 1200px;
  margin: 4rem auto;
  padding: 3rem 1rem;
  background: #fff;
  border-radius: 12px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}

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

#seien-top .service-card {
  background: #edf2f7;
  padding: 2rem;
  border-radius: 12px;
  text-align: center;
  box-shadow: 0 2px 10px rgba(0,0,0,0.05);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

#seien-top .service-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 15px rgba(0,0,0,0.1);
}

#seien-top .service-card .icon {
  font-size: 2.5rem;
  color: #4a90e2;
  margin-bottom: 1rem;
  animation: subtleMove 2s ease-in-out infinite;
}

#seien-top .service-card h3 {
  font-size: 1.4rem;
}

#seien-top .service-card p {
  font-size: 1rem;
  color: #2d3748;
}

#seien-top .footer-section {
  background: #1a202c;
  color: #f8fafc;
  padding: 3rem 1rem;
  text-align: center;
  font-size: 1rem;
}

#seien-top .footer-section .links {
  margin-bottom: 1.5rem;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.8rem 1.5rem;
}

#seien-top .footer-section a {
  color: #4a90e2;
  text-decoration: none;
  padding: 0.5rem 1rem;
  border-radius: 4px;
  transition: background 0.3s, color 0.3s;
}

#seien-top .footer-section a:hover {
  background: #a0aec0;
  color: #fff;
}

#seien-top .footer-section .social-icons {
  margin-bottom: 1.5rem;
  display: flex;
  gap: 0.8rem;
  justify-content: center;
}

#seien-top .footer-section .social-icons a {
  font-size: 1.5rem;
}

#seien-top .footer-section .social-icons a:hover {
  color: #a0aec0;
}

#seien-top .footer-section .copyright {
  font-size: 0.9rem;
  color: #a0aec0;
}

#seien-top .seien-reveal {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 360ms ease, transform 360ms ease;
}

#seien-top .seien-reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

@media (max-width: 768px) {
  #seien-top .hero-section {
    padding: 4rem 1.25rem;
    background: linear-gradient(rgba(0,0,0,0.7), rgba(0,0,0,0.7)), url('https://via.placeholder.com/768x400') center/cover no-repeat;
  }

  #seien-top .about-section table {
    font-size: 0.92rem;
  }

  #seien-top .service-card .icon {
    font-size: 2rem;
  }

  #seien-top .service-card {
    padding: 1.5rem;
  }
}