Mobile: center pinned post, pagination fixes, minor layout tweaks

- First (pinned) post on mobile: title and image centered
- Pagination: restored page counter on mobile, buttons above footer
- Typography and layout minor improvements

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

themes/hugo-theme-massively/layouts/partials/htmlhead.html

@@ -9,6 +9,27 @@
 		<title>{{ if eq (.Site.Title) (.Title) }}{{ .Site.Title }}{{ else }}{{ .Title }} &middot; {{ .Site.Title }}{{ end }}</title>
 		<meta charset="utf-8" />
 		<meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=5" />
+
+		{{ $description := "" }}
+		{{ if .Description }}{{ $description = .Description }}{{ else if .Summary }}{{ $description = .Summary | plainify | truncate 160 }}{{ else }}{{ $description = .Site.Params.description | default "Путешествия и приключения — блог о поездках по России и миру" }}{{ end }}
+		{{ $image := "" }}
+		{{ if .Params.image }}{{ $image = .Params.image | absURL }}{{ else }}{{ $image = (print .Site.BaseURL "images/desktop.webp") }}{{ end }}
+
+		<!-- SEO -->
+		<meta name="description" content="{{ $description }}" />
+		<link rel="canonical" href="{{ .Permalink }}" />
+
+		<!-- Open Graph (ВКонтакте, Telegram) -->
+		<meta property="og:type" content="{{ if .IsPage }}article{{ else }}website{{ end }}" />
+		<meta property="og:title" content="{{ if eq (.Site.Title) (.Title) }}{{ .Site.Title }}{{ else }}{{ .Title }}{{ end }}" />
+		<meta property="og:description" content="{{ $description }}" />
+		<meta property="og:url" content="{{ .Permalink }}" />
+		<meta property="og:site_name" content="{{ .Site.Title }}" />
+		<meta property="og:image" content="{{ $image }}" />
+		<meta property="og:locale" content="ru_RU" />
+		{{ if .IsPage }}
+		<meta property="article:published_time" content="{{ .Date.Format "2006-01-02T15:04:05Z07:00" }}" />
+		{{ end }}
 		<!-- CSS -->
 		{{ if hugo.IsServer }}
 		{{ $style := resources.Get "scss/main.scss" | resources.ExecuteAsTemplate "main.scss" . | toCSS (dict "targetPath" "assets/css/main.css" "enableSourceMap" true) }}