<style>
::-webkit-input-placeholder {
color: green;
}
</style>
<body>
<div>
<span style="font-size: xx-large;">T</span>he first letter in this sentence should be larger than the rest.
</div>
<div id="first-line" style="font-size: xx-large;">
This sentence should be extra-extra-large.
</div>
<input type="search" placeholder="This should be green">
</body>