/* MathViz - 数学函数可视化样式 */
* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  font-family: -apple-system, system-ui, "PingFang SC", sans-serif;
  max-width: 1200px;
  margin: 0 auto;
  padding: 20px;
  background: #f8f9fa;
  color: #333;
}
header h1 { font-size: 1.8em; color: #0066cc; }
header p { color: #666; margin-top: 4px; font-size: 0.9em; }

/* tab 切换 */
.tabs {
  display: flex;
  gap: 4px;
  margin: 20px 0 0 0;
  border-bottom: 2px solid #ddd;
}
.tab {
  padding: 10px 20px;
  background: #e9ecef;
  border: 1px solid #ddd;
  border-bottom: none;
  border-radius: 6px 6px 0 0;
  cursor: pointer;
  font-size: 0.95em;
  color: #666;
  transition: all 0.2s;
}
.tab:hover { background: #dee2e6; }
.tab.active {
  background: white;
  color: #0066cc;
  font-weight: 600;
  border-color: #0066cc;
  border-bottom: 2px solid white;
  margin-bottom: -2px;
}

/* panel */
.panel {
  display: none;
  background: white;
  padding: 20px;
  border: 1px solid #ddd;
  border-top: none;
  border-radius: 0 0 6px 6px;
}
.panel.active { display: block; }

.controls {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: center;
  margin-bottom: 16px;
  font-size: 0.9em;
}
.controls label { display: flex; align-items: center; gap: 6px; }
.controls input[type="text"] {
  padding: 6px 10px;
  border: 1px solid #ccc;
  border-radius: 4px;
  font-family: monospace;
  font-size: 0.95em;
}
.controls input[type="number"] {
  padding: 6px 8px;
  border: 1px solid #ccc;
  border-radius: 4px;
  width: 80px;
}
button {
  padding: 8px 16px;
  background: #0066cc;
  color: white;
  border: none;
  border-radius: 4px;
  cursor: pointer;
  font-size: 0.95em;
  transition: background 0.2s;
}
button:hover { background: #0052a3; }
button.secondary { background: #6c757d; }
button.secondary:hover { background: #545b62; }

canvas {
  border: 1px solid #ddd;
  background: white;
  max-width: 100%;
  height: auto;
  display: block;
}

.error {
  color: #c00;
  background: #fee;
  padding: 8px 12px;
  border-radius: 4px;
  margin-top: 8px;
  font-size: 0.9em;
  min-height: 20px;
}

footer {
  margin-top: 30px;
  padding-top: 16px;
  border-top: 1px solid #ddd;
  color: #888;
  font-size: 0.8em;
  text-align: center;
}