Question : same class name in CSS

if i have two classes with the same name in the same css file, what happens?

do they combine both? does the second one overwrite the first?

for example:

.bluetxt
{font-color: blue; font-size: 12px}

.bluetxt
{font-color: blue; font-size: 10px}

Answer : same class name in CSS

The second one will overwrite first..it'll take font-size: 10px;