/* The original classroom design is the chosen base in site.css.
   Keep only layout corrections here; the high-tech styling lives in curriculum.css.
   The white/cobalt comparison remains frozen in 試作/HPデザイン比較.html. */
:root{--header-height:0px}
@media(max-width:1000px){:root{--header-height:75px}}
@media(max-width:720px){:root{--header-height:66px}}
/* Enough room for all three rotating headings on the smallest screens. */
@media(max-width:380px){.hero h1{font-size:clamp(25px,8vw,31px);letter-spacing:0}}