问如何在div内垂直对齐span ？

<div class="container">

    <span>Some text, yay</span>

</div>

<div class="container">

    <span>Some text, yay. But shit time, there is alot of text, so we get a problem with breaking lines and the given height :( How can I align vertical now?</span>

</div>
<style>
.container {
    width: 100%;
    height: 50px;
    line-height: 50px;
    border: 1px solid black;
}

.container span {
    padding-left: 30px;
}
</style>