Fix 1:1 (ratio-square) view for Dan tri/SKDS videos: fill full height + crop width. YouTube iframe ignores object-fit, so size iframe 16:9 around 100% height, center it, slide overflow:hidden crops the sides.

static/fm_fix.css

@@ -63,3 +63,27 @@
 /* article-view top spacing so badge+title not clipped */
 .article-view .badge{margin-bottom:6px!important}
 .article-view .tts-selector{width:auto!important;display:block!important}
+
+/* ============================================================
+   1:1 ("ratio-square") view for normal horizontal Dan tri / SKDS videos.
+   Spec: fill 100% of the slide HEIGHT, crop the excess WIDTH (cut left/right).
+   A YouTube <iframe> ignores object-fit, so instead of letterboxing we size the
+   iframe to FULL slide height and 16:9 width (177.78vh -> wider than a phone),
+   center it, and let the slide's overflow:hidden clip the sides.
+   These rules load after app_v2.js's injected <style> and use !important,
+   so they override the old (broken) object-fit:contain square version.
+   ============================================================ */
+.tiktok-slide.ratio-square{position:relative!important;overflow:hidden!important;display:block!important;background:#000!important}
+.tiktok-slide.ratio-square>iframe,
+.tiktok-slide.ratio-square>video{
+  position:absolute!important;
+  top:50%!important;
+  left:50%!important;
+  transform:translate(-50%,-50%)!important;
+  height:100%!important;          /* 100% full height */
+  width:177.78vh!important;       /* 16/9 of the height -> overflow on the sides */
+  min-width:100%!important;       /* never narrower than the screen */
+  max-width:none!important;
+  max-height:none!important;
+  object-fit:cover!important;     /* affects <video>; harmless for <iframe> */
+}