body {
  margin: 0;
  padding: 0;
  font-family: Arial, Helvetica, sans-serif;
  background: #f5f5f5;
  color: #222;
}

header {
  background: #1f2937;
  color: #fff;
  padding: 18px 10px;
}

h1 {
  text-align: center;
  margin: 0;
  font-size: 28px;
}

main {
  max-width: 700px;
  margin: 20px auto;
  background: #ffffff;
  padding: 20px;
  border: 1px solid #ddd;
}

hr {
  border: none;
  border-top: 1px solid #ddd;
  margin: 10px 0 20px;
}

h2 {
  margin: 0 0 18px;
  font-size: 20px;
}

.week {
  margin-top: 18px;
  padding: 10px;
  background: #e9eef6;
  border-left: 5px solid #3b82f6;
  font-weight: bold;
}

.hw {
  margin: 8px 0 0 0;
  padding-left: 22px;
}

.hw li {
  margin: 6px 0;
}

a {
  color: #2563eb;
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

footer {
  max-width: 700px;
  margin: 12px auto 30px;
  text-align: center;
  font-size: 14px;
}

footer a {
  color: #111;
}