/* Scoped additions preserve the existing visual system. */
header{flex-wrap:wrap}
header>nav{margin-left:auto}
.site-languages{position:relative;flex:none;font-size:13px;line-height:1.5;z-index:10}
.site-languages summary{cursor:pointer;min-height:44px;display:flex;align-items:center;gap:8px;padding:10px 13px;border:1px solid var(--line);border-radius:999px;background:var(--paper);list-style:none}
.site-languages summary::-webkit-details-marker{display:none}
.site-languages summary{white-space:nowrap;gap:12px}
.site-languages .language-chevron{display:block;width:7px;height:7px;flex:0 0 7px;border-right:1.5px solid currentColor;border-bottom:1.5px solid currentColor;transform:translateY(-2px) rotate(45deg)}
.site-languages[open] .language-chevron{transform:translateY(2px) rotate(225deg)}
.site-languages summary:focus-visible,.site-languages a:focus-visible{outline:3px solid #9d662c;outline-offset:3px}
.site-languages .language-list{position:absolute;top:calc(100% + 8px);right:0;display:flex;flex-direction:column;align-items:stretch;gap:2px;margin:0;width:220px;max-width:82vw;padding:10px;border:1px solid var(--line);border-radius:16px;background:var(--paper);box-shadow:0 12px 32px #00000014;font-size:15px}
.site-languages .language-list a{display:flex;align-items:center;min-height:44px;padding:10px 14px;border-radius:8px}
.site-languages .language-list a[aria-current=true]{background:var(--ink);color:white;font-weight:600}
.site-languages .language-list a:hover{text-decoration:underline}
html:lang(zh) h1,html:lang(zh) h2,html:lang(zh) h3{letter-spacing:0;line-height:1.3}
html:lang(vi) h1,html:lang(vi) h2,html:lang(vi) h3{line-height:1.2}
@media(max-width:900px){header>nav{order:3;flex-basis:100%;margin-left:0}.site-languages{margin-left:auto}}
@media(max-width:650px){header{display:flex;align-items:center;justify-content:space-between;gap:12px}header>.brand{font-size:clamp(18px,4.4vw,24px)}header>nav{margin-top:8px;flex-wrap:wrap;justify-content:flex-start;gap:12px 18px}.site-languages{font-size:12px}.site-languages summary{padding:8px 10px;max-width:none}.site-languages .language-list{margin-top:0;gap:2px;justify-content:flex-start}.article-heading h1{overflow-wrap:anywhere}}