Issues about the theme 2025 homepage

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A few issues to note in the new homepage introduced by #1861:

1. The “Read the Annual Report” button leads to a 404 page.
2. In Diamond Sponsors, the AWS logo is larger than its containing block.
3. The animated subheading, “A nonprofit providing free TLS certificates to more than 550M websites.”, cannot be properly localized. A fallback string was added for it, and there is another similar string, but neither seems to be used anywhere. Please also note that the final period in the subheading should be localized, too.