body {
  font-family: 'Segoe UI', sans-serif;
  background: #181818;
  color: #fff;
  margin: 0;
  display: flex;
  height: 100vh;
}

header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: #202020;
  padding: 0.5rem 1rem;
  font-size: 1.3rem;
  z-index: 10;
}

#workspace {
  flex: 1;
  position: relative;
  margin-top: 3rem;
  overflow: hidden;
}

#block-area {
  position: relative;
  width: 100%;
  height: 100%;
}

.block {
  position: absolute;
  background: #2b2b2b;
  border: 1px solid #444;
  border-radius: 8px;
  padding: 8px;
  min-width: 120px;
  cursor: grab;
}

#connections {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

#sidebar {
  width: 280px;
  background: #222;
  padding: 1rem;
  overflow-y: auto;
}

h3 {
  border-bottom: 1px solid #444;
  padding-bottom: 5px;
}