Dracula is full of details that put it in what was at the time an incredibly modern time frame, which only isn't obvious to readers now because it's been more than a hundred years. A few off the top of my head:
Jonathan brings photographs of the properties to show to Dracula that he took with a Kodak portable camera.
Seward keeps an audio journal via phonograph recording.
Seward being a psychiatrist- the idea that you could actually try to talk to and understand a "lunatic" in order to help them get better instead of just throwing away the key was a depressingly novel concept in medicine at the time. Freud's Studies on Hysteria only came out two years before Dracula, for instance.
Blood transfusions. It's easy to make jokes about how Dracula was written before people knew about blood types and that's why Lucy gets transfusions from so many people with no problem, but because blood types wouldn't be discovered until 3 years after it was published, blood transfusion was still an extremely experimental and risky treatment that many doctors would hesitate to even consider, because sometimes when it was performed the patient would instantly die and no one knew why.
Mina's joke about "the New Woman"- anxieties about gender and feminism in Dracula are the kind of thing whole theses have been written about, but there's an obvious irony to this comment because Mina kind of is the New Woman. In contrast to Lucy, Mina is a highly-educated woman with a real actual job, and she works to hone those practical job skills because she plans to be an active participant in Jonathan's work.
When Van Helsing decks Lucy's room out with garlic flowers, he telegrams to Holland for overnight shipping across the Channel from a friend who owns a greenhouse, because garlic flowers are a good 3 months or so out of season at the time the chapter is set.
Jonathan literally makes a comment in Chapter 3 about the surreal contrasting modernity of sitting at an antique desk in an ancient castle and frantically scribbling steganographic shorthand in his notebook.