body {
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  height: 100vh;
}
header {
  background: #004080;
  color: white;
  padding: 1em;
  text-align: center;
}
header h1 {
  margin: 0;
}
header h2 {
  margin: 0.2em 0 0;
  font-weight: normal;
}
#container {
  display: flex;
  flex: 1;
  overflow: hidden;
}
#sidebar {
  width: 200px;
  background: #f0f0f0;
  padding: 1em;
  overflow-y: auto;
}
#sidebar ul {
  list-style: none;
  padding: 0;
}
#sidebar li {
  padding: 0.3em;
  cursor: pointer;
}
#sidebar li:hover {
  background: #ddd;
}
#content {
  flex: 1;
  display: flex;
  flex-direction: column;
  padding: 1em;
  overflow: hidden;
}
#filter-bar {
  margin-bottom: 0.5em;
}
#filter-input {
  width: 100%;
  padding: 0.5em;
  font-size: 1em;
}
#item-list {
  flex: 1;
  overflow-y: auto;
  border: 1px solid #ccc;
  padding: 0.5em;
}
.item {
  border-bottom: 1px solid #ddd;
  padding: 0.5em 0;
}
.item h4 {
  margin: 0;
}
footer {
  background: #f0f0f0;
  text-align: center;
  padding: 0.5em;
  font-size: 0.9em;
}