In attesa di qualche eventuale risposta provando e riprovando o modificato così da smartphone mi funziona, con Edge in tutti i formati, con Smiljet (base Chrome) non tutti i formati:
Da Così
@media (prefers-reduced-motion:no-preference){:root{scroll-behavior:smooth}}body{-webkit-text-size-adjust:100%;-webkit-tap-highlight-color:rgba(0,0,0,0);background-color:var(--body-bg);color:var(--body-color);font-family:var(--body-font-family);font-size:var(--body-font-size);font-weight:var(--body-font-weight);line-height:var(--body-line-height);margin:0;text-align:var(--body-text-align)}hr{background-color:currentColor;border:0;color:inherit;margin:1rem 0;opacity:.25}hr:not([size]){height:1px}.h1,.h2,.h3,.h4,.h5,.h6,h1,h2,h3,h4,h5,h6{font-weight:500;line-height:1.2;margin-bottom:.5rem;margin-top:0}.h1,h1{font-size:calc(1.375rem + 1.5vw)}@media (min-width:1200px){.h1,h1{font-size:2.5rem}}.h2,h2{font-size:calc(1.325rem + .9vw)}@media (min-width:1200px){.h2,h2{font-size:2rem}}.h3,h3{font-size:calc(1.3rem + .6vw)}@media (min-width:1200px){.h3,h3{font-size:1.75rem}}.h4,h4{font-size:calc(1.275rem + .3vw)}@media (min-width:1200px){.h4,h4{font-size:1.5rem}}.h5,h5{font-size:1.25rem}.h6,h6{font-size:1rem}
a così
@media (prefers-reduced-motion:no-preference){:root{scroll-behavior:smooth}}body{-webkit-text-size-adjust:100%;-webkit-tap-highlight-color:rgba(0,0,0,0);background-color:var(--body-bg);color:var(--body-color);font-family:var(--body-font-family);font-size:var(--body-font-size);font-weight:var(--body-font-weight);line-height:var(--body-line-height);margin:0;text-align:var(--body-text-align)}hr{background-color:currentColor;border:0;color:inherit;margin:1rem 0;opacity:.25}hr:not([size]){height:1px}.h1,.h2,.h3,.h4,.h5,.h6,h1,h2,h3,h4,h5,h6{font-weight:500;line-height:1.2;margin-bottom:.5rem;margin-top:0}.h1,h1{font-size:calc(1.7rem + 1.5vw)}@media (min-width:375px){.h1,h1{font-size:1.7rem ;color: #135cae;}}.h2,h2{font-size:calc(1.3rem + .9vw)}@media (min-width:375px){.h2,h2{font-size:1.3rem}}.h3,h3{font-size:calc(1.1rem + .6vw)}@media (min-width:375px){.h3,h3{font-size:1.1rem}}.h4,h4{font-size:calc(1rem + .3vw)}@media (min-width:375px){.h4,h4{font-size:1rem}}.h5,h5{font-size:0.95rem}.h6,h6{font-size:0.9rem}