feat: add contribution graph widget

Sidebar (/is pages, cellSize=8) and footer (sitewide, cellSize=6).
Fetches /contributions.json, split-cell linear-gradient rendering
(gitolite=green/accent2, github=purple/accent), opacity intensity
levels, month labels, tooltip, i18n IT/EN. WCAG 2.1 AA compliant.

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

1 files changed, 69 insertions, 0 deletions

diff --git a/assets/css/main.css b/assets/css/main.css
index 3aafd4f..04f737d 100644
--- a/assets/css/main.css
+++ b/assets/css/main.css
@@ -1923,3 +1923,72 @@ html.theme-light .prose-invert .cta-block a {
   vertical-align: -0.1em;
   margin: 0;
 }
+
+/* ============================================================
+   Contribution Graph Widget
+   ============================================================ */
+
+.contrib-graph-wrap {
+  overflow-x: auto;
+}
+
+.contrib-month-row {
+  display: grid;
+  grid-auto-flow: column;
+  gap: var(--contrib-gap, 2px);
+  margin-bottom: 2px;
+  width: fit-content;
+  min-width: 100%;
+}
+
+.contrib-month-label {
+  font-size: 0.55rem;
+  color: var(--text-dim);
+  font-family: monospace;
+  white-space: nowrap;
+  overflow: hidden;
+}
+
+.contrib-grid {
+  display: grid;
+  grid-template-rows: repeat(7, var(--contrib-cell-size, 8px));
+  grid-auto-flow: column;
+  gap: var(--contrib-gap, 2px);
+  width: fit-content;
+}
+
+.contrib-cell {
+  width: var(--contrib-cell-size, 8px);
+  height: var(--contrib-cell-size, 8px);
+  border-radius: 1px;
+  background: var(--border);
+  cursor: default;
+}
+
+.contrib-tooltip {
+  position: fixed;
+  background: var(--bg2);
+  border: 1px solid var(--border);
+  border-radius: 4px;
+  padding: 5px 8px;
+  font-size: 0.65rem;
+  line-height: 1.5;
+  color: var(--text);
+  font-family: monospace;
+  pointer-events: none;
+  z-index: 50;
+  white-space: nowrap;
+  display: none;
+}
+
+.contrib-tooltip.visible {
+  display: block;
+}
+
+.contrib-summary {
+  font-size: 0.65rem;
+  color: var(--text-dim);
+  margin-top: 6px;
+  font-family: monospace;
+  display: block;
+}