:root {
  --bg: #f1f5f9;
  --card: #ffffff;
  --text: #1e293b;
  --muted: #64748b;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --border: #cbd5e1;
}

body {
  font-family: Arial, sans-serif;
  padding: 20px;
  background: var(--bg);
  color: var(--text);
  display: flex;
  justify-content: center;
  align-items: flex-start;
  min-height: 100vh;
}

.container {
  max-width: 900px;
  width: 100%;
  background: var(--card);
  padding: 24px;
  border-radius: 12px;
  box-shadow: 0 6px 20px rgba(0,0,0,0.15);
}

h1 {
  font-size: 24px;
  margin-bottom: 4px;
  color: var(--accent);
}

.subtitle {
  color: var(--muted);
  font-size: 14px;
  margin-bottom: 20px;
}

.controls {
  display: flex;
  justify-content: center;
  margin-bottom: 12px;
}

.swap-btn {
  font-size: 20px;
  padding: 8px 14px;
  border: 1px solid var(--border);
  border-radius: 50%;
  background: var(--accent);
  color: white;
  font-weight: bold;
  cursor: pointer;
  transition: transform 0.3s ease, background 0.2s ease;
}

.swap-btn:hover {
  background: var(--accent-hover);
  transform: rotate(180deg);
}

.editor {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.box {
  display: flex;
  flex-direction: column;
}

.box h3 {
  margin-bottom: 6px;
  font-size: 16px;
  color: var(--muted);
}

textarea {
  width: 100%;
  min-height: 150px;
  padding: 12px;
  border-radius: 8px;
  border: 1px solid var(--border);
  font-size: 14px;
  resize: vertical;
  margin-bottom: 8px;
}

button {
  padding: 8px 14px;
  border: none;
  border-radius: 6px;
  background: var(--accent);
  color: white;
  font-weight: bold;
  cursor: pointer;
  transition: background 0.2s ease;
  align-self: flex-start;
}

button:hover {
  background: var(--accent-hover);
}

.examples-section {
  margin-top: 20px;
}

.examples-section h3 {
  margin-bottom: 8px;
  font-size: 16px;
  color: var(--accent);
}

.examples-section button {
  margin: 4px;
  font-size: 13px;
}

footer {
  margin-top: 24px;
  font-size: 13px;
  color: var(--muted);
  text-align: center;
}