:root {
  --primary-color: #3498db;
  --secondary-color: #2c3e50;
  --accent-color: #e74c3c;
  --light-color: #ecf0f1;
  --dark-color: #34495e;
  --predicate-color: #9b59b6;
  --blank-node-color: #f39c12;
  --success-color: #2ecc71;
}

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

body {
  background-color: var(--light-color);
  color: var(--dark-color);
  line-height: 1.6;
  padding: 20px;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  background-color: white;
  border-radius: 8px;
  box-shadow: 0 4px 6px rgba(0,0,0,0.1);
  overflow: hidden;
}

header {
  background-color: var(--primary-color);
  color: white;
  padding: 20px;
  border-radius: 4px;
  text-align: center;
}

h1 {
  margin-bottom: 10px;
  font-weight: 300;
  font-size: 2.2em;
}

footer {
  text-align: center;
  padding: 20px;
  background-color: var(--primary-color);
  color: white;
  font-size: 0.9em;
  border-radius: 4px;
}

.app-content {
  display: flex;
  flex-direction: column;
  padding: 20px;
}

.section-heading {
  font-size: 1.1em;
  color: var(--secondary-color);
  margin-bottom: 12px;
  font-weight: 600;
  border-left: 3px solid var(--primary-color);
  padding-left: 10px;
  text-align: left;
}

.input-section {
  margin-bottom: 20px;
}

.textarea-container {
  position: relative;
  margin-top: 15px;
  margin-bottom: 15px;
}

textarea {
  width: 100%;
  height: 200px;
  padding: 15px;
  border: 1px solid #ddd;
  border-radius: 4px;
  resize: vertical;
  font-family: monospace;
  font-size: 14px;
  transition: border-color 0.3s;
}

textarea:focus {
  border-color: var(--primary-color);
  outline: none;
}

.button-container {
  display: flex;
  gap: 10px;
  justify-content: space-between;
}

.init-buttons {
  display: flex;
  gap: 10px;
  justify-content: flex-start;
}

.interact-buttons {
  display: flex;
  gap: 10px;
  justify-content: flex-end;
}

button {
  padding: 10px 20px;
  background-color: var(--primary-color);
  color: white;
  border: none;
  border-radius: 4px;
  cursor: pointer;
  transition: background-color 0.3s;
  font-size: 14px;
}

button:hover {
  background-color: #2980b9;
}

button.example {
  background-color: var(--secondary-color);
}

button.example:hover {
  background-color: #1a252f;
}

button.clear {
  background-color: var(--accent-color);
}

button.clear:hover {
  background-color: #c0392b;
}

button.secondary {
  background-color: var(--secondary-color);
}

button.secondary:hover {
  background-color: #1a252f;
}

.message {
  padding: 10px;
  margin-top: 10px;
  border-radius: 4px;
  background-color: rgba(46,204,113,0.1);
  color: var(--success-color);
  display: none;
}

.error {
  background-color: rgba(231,76,60,0.1);
  color: var(--accent-color);
}

.graph-container {
  height: 600px;
  border: 1px solid #ddd;
  border-radius: 4px;
  cursor: grab;
}

.legend {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 20px;
  margin-top: 20px;
  background-color: rgba(236,240,241,0.5);
  border-radius: 4px;
}

.legend-items {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
}

.legend-item {
  display: flex;
  align-items: center;
  font-size: 14px;
}

.legend-color {
  width: 15px;
  height: 15px;
  margin-right: 8px;
  border-radius: 3px;
}

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