body {
  font-family: system-ui, sans-serif;
  background: #ffffff;
  color: #222;
  padding: 2rem;
  max-width: 800px;
  margin: auto;
}

h1 {
  font-size: 2rem;
  border-bottom: 2px solid #ccc;
  margin-bottom: 1.5rem;
}

h2 {
  font-size: 1.4rem;
  margin-top: 2rem;
  border-left: 4px solid #4a90e2;
  padding-left: 0.5rem;
}

ul {
  list-style: disc;
  padding-left: 1.5rem;
}

li {
  margin-bottom: 0.5rem;
}

.done {
  text-decoration: line-through;
  color: #999;
}

a {
  color: #4a90e2;
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

section {
  margin-bottom: 2rem;
}

.tag {
  background: #eee;
  padding: 0.2em 0.5em;
  border-radius: 4px;
  font-size: 0.9em;
  margin-left: 0.5rem;
}

.meta {
  font-size: 0.85em;
  color: #666;
  margin-top: 0.2em;
}

button {
  background-color: #4a90e2;
  color: white;
  padding: 0.5em 1em;
  font-size: 1rem;
  font-family: inherit;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  transition: background-color 0.2s ease, box-shadow 0.2s ease;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

button:hover {
  background-color: #3b78c5;
}

button:active {
  background-color: #336aa8;
  box-shadow: inset 0 2px 4px rgba(0,0,0,0.2);
}

button:disabled {
  background-color: #ccc;
  color: #666;
  cursor: not-allowed;
}