:root {
  --primary: #1d4ed8;
  --text: #1f2933;
  --muted: #6b7280;
  --bg: #f9fafb;
  --card: #ffffff;
}

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

body {
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  padding: 16px;
}

.container {
  max-width: 900px;
  margin: auto;
  background: var(--card);
  padding: 20px;
  border-radius: 12px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.06);
}

h1 {
  font-size: 1.8rem;
  text-align: center;
  color: var(--primary);
  margin-bottom: 20px;
}

h2 {
  font-size: 1.3rem;
  margin-top: 28px;
  margin-bottom: 10px;
  color: #111827;
  border-left: 4px solid var(--primary);
  padding-left: 10px;
}

h3 {
  font-size: 1.1rem;
  margin-top: 22px;
  margin-bottom: 8px;
  color: #1f2937;
}

p {
  margin-bottom: 12px;
  font-size: 0.97rem;
}

ul {
  margin-left: 18px;
  margin-bottom: 14px;
}

li {
  margin-bottom: 8px;
  font-size: 0.95rem;
}

.highlight {
  background: #eef2ff;
  padding: 12px;
  border-radius: 8px;
  margin: 14px 0;
  border-left: 4px solid var(--primary);
}

.note {
  background: #fefce8;
  padding: 12px;
  border-radius: 8px;
  border-left: 4px solid #eab308;
  margin: 14px 0;
  font-size: 0.95rem;
}

footer {
  margin-top: 30px;
  text-align: center;
  font-size: 0.85rem;
  color: var(--muted);
}

  .image-buttons a {
    display: inline-block;
    margin: 10px;
  }

  .image-buttons img {
    width: 80px;
    height: 80px;
    object-fit: cover;
    border-radius: 8px;
    box-shadow: 0 0 5px rgba(0,0,0,0.2);
    transition: transform 0.3s ease;
  }

  .image-buttons img:hover {
    transform: scale(1.05);
  }

.nav-buttons {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 20px;
    margin: 20px 0;
}

.nav-buttons a {
    text-decoration: none;
    padding: 10px 22px;
    background-color: #2563eb; /* blue */
    color: #ffffff;
    font-weight: 500;
    border-radius: 8px;
    transition: all 0.3s ease;
}

.nav-buttons a:hover {
    background-color: #1e40af;
    transform: translateY(-2px);
}


@media (max-width: 600px) {
  h1 {
    font-size: 1.5rem;
  }

  h2 {
    font-size: 1.15rem;
  }
}