:root {
  --primary: #2d6cdf;
  --secondary: #f5f7fa;
  --accent: #f9a825;
  --text: #222;
  --bg: #fff;
}

body {
  font-family: 'Segoe UI', Arial, sans-serif;
  background: #b3e0ff; /* biru muda ramah low vision */
color: #0a2540;
  margin: 0;
  padding: 0;
  line-height: 1.6;
}

header, nav, main, footer {
  max-width: 800px;
  margin: auto;
  padding: 1rem;
}

header {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.logo {
  width: 60px;
  height: 60px;
  object-fit: contain;
}

h1, h2, h3 {
  font-weight: 700;
}

.materials {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  justify-content: center;
}

.material-card {
  background: var(--bg);
  border-radius: 12px;
  box-shadow: 0 2px 8px #0001;
  width: 220px;
  padding: 1rem;
  text-align: center;
  transition: box-shadow 0.2s;
}

.material-card:focus-within, .material-card:hover {
  box-shadow: 0 4px 16px #0002;
}

.material-card img {
  width: 100%;
  height: 100px;
  object-fit: cover;
  border-radius: 8px;
}

button, .btn {
  display: block;
  width: 100%;
  padding: 0.75em;
  margin: 0.5em 0;
  font-size: 1.1em;
  background: var(--primary);
  color: #fff;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  transition: background 0.2s;
}

button:focus, .btn:focus {
  outline: 3px solid var(--accent);
}

button[disabled], .btn[disabled] {
  background: #aaa;
  cursor: not-allowed;
}

a {
  color: var(--primary);
  text-decoration: underline;
}

@media (max-width: 600px) {
  .materials {
    flex-direction: column;
    align-items: center;
  }
  .material-card {
    width: 90vw;
  }
  header {
    flex-direction: column;
    align-items: flex-start;
  }
}