* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
  background: #f4f7fb;
  color: #1f2933;
}

/* Header and navigation */

.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 18px 8%;
  background: #0f172a;
  color: white;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  color: white;
  text-decoration: none;
  font-size: 1.2rem;
  font-weight: bold;
}

.logo {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: 10px;
  background: #38bdf8;
  color: #0f172a;
  font-weight: bold;
}

nav {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 22px;
}

nav a {
  color: white;
  text-decoration: none;
  transition: color 0.2s ease;
}

nav a:hover,
nav a:focus {
  color: #93c5fd;
}

nav a.active {
  color: #38bdf8;
}

/* Hero section */

.hero {
  padding: 80px 12%;
  text-align: center;
  background: linear-gradient(135deg, #1e3a8a, #0f172a);
  color: white;
}

.hero h1 {
  margin: 0 0 16px;
  font-size: 2.5rem;
}

.hero p {
  max-width: 720px;
  margin: 0 auto;
  font-size: 1.1rem;
  line-height: 1.7;
}

/* Gallery section */

.gallery-card {
  width: 80%;
  max-width: 850px;
  margin: 50px auto;
  padding: 32px;
  text-align: center;
  background: white;
  border-radius: 14px;
  box-shadow: 0 8px 24px rgba(15, 23, 42, 0.08);
}

.gallery-card h2 {
  margin-top: 0;
}

#image-label {
  margin-bottom: 20px;
}

#demo-image {
  display: block;
  width: 100%;
  max-width: 650px;
  height: 360px;
  margin: 0 auto 28px;
  object-fit: cover;
  border: 1px solid #d9e2ec;
  border-radius: 12px;
}

button {
  padding: 12px 22px;
  border: none;
  border-radius: 8px;
  background: #38bdf8;
  color: #0f172a;
  font-weight: bold;
  cursor: pointer;
  transition: background 0.2s ease;
}

button:hover,
button:focus {
  background: #7dd3fc;
}

/* Footer */

footer {
  padding: 22px;
  text-align: center;
  background: #0f172a;
  color: white;
}

/* Responsive layout */

@media (max-width: 900px) {
  .navbar {
    flex-direction: column;
    gap: 18px;
  }

  nav {
    justify-content: center;
  }
}

@media (max-width: 600px) {
  .hero {
    padding: 60px 8%;
  }

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

  nav {
    flex-direction: column;
    gap: 12px;
  }

  .gallery-card {
    width: calc(100% - 32px);
    padding: 22px;
  }

  #demo-image {
    height: 240px;
  }
}