UX improvement ideas

[juntyr]

• change the default plot download from PNG (anyone can make a screenshot) to SVG (still not PDF but at least portable vector graphics): https://plotly.com/javascript/configuration-options/#customize-download-plot-options
• enable responsiveness (if not already done): https://plotly.com/javascript/configuration-options/#making-a-responsive-chart
• hide the plotly ads: https://plotly.com/javascript/configuration-options/#hide-the-plotly-logo-on-the-modebar
• Plotly templates #25 change the plot theme (also for SMILES) when the dark/light mode is switched: https://plotly.com/python/templates/
• add dark mode for the status/warning/error messages
• add dark mode for SMILES strings