H1: html5 outline for a nest of sections (1)

<section>

H1: Heading of section level 1

p: text of the first section

<section>

H1: Heading of section level 2

p: this section is nested in section level 1

<section>

H1: Heading 1 of section level 3

p: this section is nested in section level 2

H1: Heading 2 of this section

p: also in this section

<section>

H1: Heading of section level 4

p: this section is nested in section level 3

<section>

H1: Heading of section level 5

p: this section is nested in section level 4

<section>

H1: Heading of a new section level 3

p: this section is also nested in section level 2

No explicit font-size for the H1, no explicit font-size for the p.
The headers H1 in the nested <section>'s are renderered as H2, H3, H4, etc.!
Tested nov. 2013 in Firefox 23/24/25, Chrome 30, Opera 17, Safari-Win (5.1.7) and IE 9/10/11: all the same.
Exception: Opera 12.16 (latest Linux version): all H1 have the same font-size (as test 3).
Note: the font-size of the paragraph's <p> is unaffected.
Outline according to the w3c Semantic Data Extractor:
Outline of the document
- H1: html5 outline for a nest of sections (1)
- H1: Heading of section level 1
- H1: Heading of section level 2
- H1: Heading 1 of section level 3
- H1: Heading 2 of this section
- H1: Heading of section level 4
- H1: Heading of section level 5
- H1: Heading of a new section level 3
For visitors with AT (Assistive Technologie) this is not a meaningful outline structure.