Some of the issues pertaining to Indian languages:

1.  Styling of first character:

     Here are some of the examples of words with the first character / syllable with some styling applied to them.  Generally we find that first syllable will have the styling applied to it, not the first character only. This is specified in your example also.

स्थिति (Positon)

स्थिति (Positon)

प्रस्थान (Departure)

    But there are some examples where it is not clear. As in some more examples mentioned below, there are mono-syllabic words. Here if we go by the above rule then the whole word will have the style applied to it, because the word itself is mono-syllable. Probably the style may apply to first Conjunct or may be glyph?

e.g.

स्वर (Vowel)

कोश (Dictionary)

If the word has some Anuswar after the first consonant/character, then whether the style would apply to Anuswar symbol also. In Microsoft Word the first character with Anuswar ( here हिं )  is probably the single glyph, and style applies to it

हिंदी (Hindi)

हिंदी (Hindi)

संतरा (Orange)

केंद्रीय (Central)

Same is the case with Chandabindu

e.g. चाँद (moon)

If the word has Half ‘na’  character in place of Anuswar symbol then most probably the style would not apply to Half ‘na’  character along with first character. In Microsoft Word the first character without Half ‘na’ ( here हि )  is probably the single glyph, and rest of the part न्दी is a single glyph and style applies to हि only.

e.g.

हिन्दी (Hindi)

हिन्दी (Hindi)

If  the word starts with a ligature then

क्षेत्रीय (Regional)

क्षत्रिय    (A Hindu cast name)

So, it seems that the style applies to the glyph, not the syllable or conjunct or first character only.