* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

html, body {
  height: 100%;
  margin: 0;
  display: flex;
  flex-direction: column;
}

body {
  background-color: #f7f7f7;
  color: #333;
  line-height: 1.6;
}

header {
  background-color: #1e293b;
  color: white;
  text-align: center;
  padding: 2rem 1rem;
}

header img {
  width: 120px;
  border-radius: 50%;
  margin-top: 1rem;
  border: 3px solid #fff;
}

main {
  flex: 1;
  max-width: 1000px;
  margin: 2rem auto;
  padding: 0 1rem;
}

section {
  margin-bottom: 2rem;
}

h2 {
  font-size: 1.8rem;
  margin-bottom: 1rem;
  color: #1e293b;
}

ul, ol {
  list-style: none;
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  padding-left: 0;
}

li {
  background: white;
  border: 1px solid #ddd;
  padding: 1rem;
  border-radius: 0.5rem;
  box-shadow: 0 2px 5px rgba(0,0,0,0.05);
  transition: transform 0.2s ease;
}

li:hover {
  transform: translateY(-3px);
}

a {
  text-decoration: none;
  color: #0f172a;
  font-weight: bold;
}

footer {
  background-color: #1e293b;
  color: white;
  text-align: center;
  padding: 1rem;
  margin-top: 3rem;
}


ul, ol {
  list-style: none;
  padding-left: 0;
  display: grid;
  gap: 1rem;
}


#assignments ol {
  grid-template-columns: repeat(3, 1fr);
}


@media (max-width: 768px) {
  #assignments ol {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 480px) {
  #assignments ol {
    grid-template-columns: 1fr;
  }
}