0661名無しさん@お腹いっぱい。垢版2018/07/10(火) 13:54:46.44ID:uh79aIhD0 >>660 @-moz-document url("chrome://browser/content/browser.xul") { #sidebar-box, #sidebar-box > #sidebar { min-width: 0 !important; max-width: 480px !important; overflow-x: hidden !important; } }