With high-set communal tables, deep-gray walls and hanging gardens, Maven defies the grunge-era aesthetic that has dominated Lower Haight bars since the 1990s. Kate Bolton's cocktails, many of which are tinged with Asian flavors, are quirky and fresh; the best of them may be the Global Warming, with aged gin, sake, Riesling, lemon juice, and shards of ice from a melting absinthe glacier.