body {
  font-family: 'Segoe UI', Arial, sans-serif;
  margin: 0;
  background: #f5f7fb;
  color: #263238;
}
header {
  background: #19202a;
  color: #fff;
  padding: 0.5rem 0;
}
nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 1.5rem;
}
nav .logo {
  font-weight: 700;
  font-size: 1.3rem;
  letter-spacing: 1px;
}
nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
}
nav ul li {
  margin-left: 2rem;
}
nav ul li a {
  color: #fff;
  text-decoration: none;
  font-weight: 500;
  padding-bottom: 4px;
}
nav ul li a.active,
nav ul li a:hover {
  border-bottom: 2px solid #3eb489;
}
.hero {
  text-align: center;
  padding: 3.5rem 1.5rem 2rem 1.5rem;
  background: linear-gradient(120deg, #3eb489 0%, #19202a 95%);
  color: #fff;
}
.hero h1 {
  font-size: 2.5rem;
  margin-bottom: 0.7rem;
}
.hero p {
  font-size: 1.3rem;
  margin-bottom: 1.5rem;
}
.hero-img {
  width: 300px;
  border-radius: 18px;
  margin-top: 2rem;
  box-shadow: 0 8px 24px rgba(52,72,118,0.15);
}
.features {
  display: flex;
  flex-wrap: wrap;
  gap: 2rem;
  max-width: 1100px;
  margin: 2.5rem auto;
  justify-content: center;
}
.feature-card {
  background: #fff;
  border-radius: 12px;
  box-shadow: 0 4px 12px rgba(30, 34, 90, 0.07);
  padding: 1.5rem 2rem;
  flex: 1 1 270px;
  max-width: 340px;
  text-align: center;
}
.feature-card img {
  width: 64px;
  margin-bottom: 1rem;
}
.feature-card h2 {
  font-size: 1.1rem;
  margin-bottom: 0.5rem;
  color: #3eb489;
}
footer {
  background: #19202a;
  color: #fff;
  text-align: center;
  padding: 1rem 0;
  margin-top: 2rem;
}
.about-section {
  max-width: 700px;
  margin: 3rem auto;
  background: #fff;
  border-radius: 16px;
  padding: 2.5rem 2rem;
  box-shadow: 0 4px 14px rgba(30, 34, 90, 0.08);
  text-align: center;
}
.about-section img {
  width: 240px;
  border-radius: 12px;
  margin: 1.5rem 0;
}
@media (max-width: 800px) {
  .features {
    flex-direction: column;
    gap: 1.3rem;
    padding: 0 0.5rem;
  }
  nav ul li {
    margin-left: 1rem;
  }
  .feature-card {
    max-width: 100%;
    padding: 1.5rem 1rem;
  }
  .about-section {
    padding: 2rem 0.8rem;
  }
}