/* hoan-thue-tai-xe brand (thiet-ke handoff, Q-0951, kit/nhan-dien layer). Copy verbatim; replaces the inline <style> of site/index.html. Indigo #4338ca + small coin gold. */
:root{color-scheme:light dark;--bg:#f7f7fd;--surface:#ffffff;--line:#cfd0ee;--text:#16162b;--muted:#4a4a68;--brand:#4338ca;--brand-hover:#3730a3;--brand-ink:#4338ca;--brand-soft:#e8e9fb;--on-brand:#ffffff;--warn-bg:#fff3cd;--warn-line:#b45309;--warn-text:#4a2f05;--err:#b42318}
@media (prefers-color-scheme:dark){:root{--bg:#0f0f23;--surface:#181833;--line:#34346b;--text:#ececfa;--muted:#b9b9d8;--brand:#a5b4fc;--brand-hover:#c7d2fe;--brand-ink:#c7d2fe;--brand-soft:#23234a;--on-brand:#1e1b4b;--warn-bg:#3a2a08;--warn-line:#f59e0b;--warn-text:#fde9b8;--err:#fca5a5}}
*,*::before,*::after{box-sizing:border-box}
html{background:var(--bg);-webkit-text-size-adjust:100%}
body{margin:0 auto;max-width:760px;padding:16px 16px 64px;background:var(--bg);color:var(--text);font:17px/1.6 system-ui,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;overflow-wrap:anywhere}
a{color:var(--brand-ink)}
.topbar{display:flex;align-items:center;padding:4px 0}
.brand{display:inline-flex;align-items:center;gap:10px;min-height:48px;font-weight:700;font-size:1.125rem;color:var(--brand-ink);text-decoration:none;white-space:nowrap}
.logo{width:28px;height:28px;flex:none}
h1{font-size:1.875rem;line-height:1.25;margin:.5em 0 .3em}
h2{margin-top:1.8em;font-size:1.375rem;line-height:1.3}
h3{font-size:1.125rem}
.warn{background:var(--warn-bg);color:var(--warn-text);border:2px solid var(--warn-line);padding:12px 14px;border-radius:12px;font-size:.95rem}
label{display:block;margin-top:12px;font-weight:600}
input,select,textarea,button{font:inherit;width:100%;margin-top:4px;padding:10px 12px;min-height:48px;border-radius:10px;border:1px solid var(--line);background:var(--surface);color:var(--text)}
button{width:auto;min-width:48px;margin-top:14px;padding:0 22px;font-weight:600;border-radius:999px;border-color:var(--brand);background:var(--brand);color:var(--on-brand);cursor:pointer}
button.alt{background:transparent;color:var(--brand-ink)}
button:hover{background:var(--brand-hover);border-color:var(--brand-hover);color:var(--on-brand)}
button:disabled{opacity:.55;cursor:not-allowed}
button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible,textarea:focus-visible,summary:focus-visible{outline:3px solid var(--brand-ink);outline-offset:2px}
table{width:100%;border-collapse:collapse;margin:12px 0;background:var(--surface)}
td,th{border:1px solid var(--line);padding:8px 10px;font-size:.9rem;text-align:left}
td input{margin-top:0;padding:8px}
th{background:var(--brand-soft);color:var(--text)}
#result{margin-top:16px;padding:14px;border:2px solid var(--brand);border-radius:12px;background:var(--surface);display:none}
summary{cursor:pointer;min-height:48px;display:flex;align-items:center}
small,footer{color:var(--muted)}
footer{margin-top:32px;font-size:.85rem}
[hidden]{display:none}
@media (max-width:640px){h1{font-size:1.5rem}table{display:block;overflow-x:auto}}