To look on scale and real is different. On scale, the more you gain muscle, you will gain weight but you will look leaner. On real, if you want to look just leaner and drop some weight, you have to be in calorie deficit and do not gain muscle and feed the muscle. Basically eat more vegie but do not eat lean protein. There is no secret for loosing weight in number. Just to be in calorie deficit either eating smaller and or more exercise to loose some calorie.
How tall are you, how much do you weight, whats your diet like? Running won't make you muscular, though it can be good for your heart and flushing toxins out of your system. But if you want to look muscular, 30-40 minutes of cardio won't do it. Genetics has a lot to do with how muscular people look, but it takes work to build muscle, and doing a lot of cardio builds particular muscles but not all muscles. Bicycling on hills, for example, will give you great thighs, but won't do anything about arms. To do overall weight training means days spent on upper body and days spent on lower body, and if you're not particularly prone to putting on muscle it means a lot more time put in to get your reps. What you have to decide is, what do you like to do, and is looking a certain way more important to you than doing what you like, which seems to be running, which leaves people thin but not muscular.
Have you been eating the correct foods? More veg and lean meat? Less sugar? I had to vary my work outs and trick my body. It took a while but ended up working