<style>
::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>
    <div id="first-line" style="font-size: xx-large;">
        This sentence should be extra-extra-large too.
    </div>
    <input type="search" placeholder="This should be green">
</body>