:root{color-scheme:light dark;
--bg:#f2f5f1;--card:#ffffff;--card2:#f8faf7;--ink:#182720;--muted:#61716a;
--line:#dfe6df;--line2:#edf1ec;
--accent:#177245;--accent-2:#0f5c37;--accent-soft:#e3f1e9;
--warn:#b0451f;--warn-soft:#fbeee8;--info:#2b5f8a;--info-soft:#e7eff6;
--r:11px;--r-sm:8px;
--shadow:0 1px 2px rgba(22,39,28,.05),0 4px 14px rgba(22,39,28,.05);
--shadow-lg:0 6px 24px rgba(22,39,28,.10)}
@media(prefers-color-scheme:dark){:root{
--bg:#0d1411;--card:#161f1a;--card2:#121a15;--ink:#e8efe9;--muted:#98a69d;
--line:#26332c;--line2:#1d2822;
--accent:#4dbb85;--accent-2:#6fd0a0;--accent-soft:#173425;
--warn:#e08a63;--warn-soft:#2e1d15;--info:#7db2dc;--info-soft:#15242f;
--shadow:0 1px 2px rgba(0,0,0,.35),0 4px 14px rgba(0,0,0,.25);
--shadow-lg:0 8px 28px rgba(0,0,0,.45)}}
*{box-sizing:border-box}
body{margin:0;background:var(--bg);color:var(--ink);
font:14.5px/1.55 -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;
-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--r);
padding:1rem 1.1rem;margin:.8rem 0;box-shadow:var(--shadow)}
/* Tiêu đề thẻ: chữ THƯỜNG có trọng lượng — tiếng Việt viết hoa toàn bộ thì
   dấu chồng lên nhau, đọc mệt. Trọng lượng và cỡ chữ làm việc phân cấp. */
h2{font-size:.94rem;color:var(--ink);margin:0 0 .65rem;font-weight:700;letter-spacing:-.01em}
.mono{font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:.83rem}
.meta{color:var(--muted);font-size:.86rem}
.note{color:var(--muted);font-size:.85rem;margin:.6rem 0 0}
.scroll{overflow-x:auto;-webkit-overflow-scrolling:touch}
::selection{background:var(--accent-soft)}
html{scroll-behavior:smooth}
a,button,input,select,summary{transition:background-color .14s ease,border-color .14s ease,
color .14s ease,box-shadow .14s ease,opacity .14s ease}
:focus-visible{outline:2px solid var(--accent);outline-offset:2px;border-radius:4px}
@media(prefers-reduced-motion:no-preference){
  .wrap>*:not(.side):not(.topbar2):not(.mo-menu):not(.nut-menu){
    animation:hien .28s cubic-bezier(.2,.7,.3,1) both}
  @keyframes hien{from{opacity:0;transform:translateY(6px)}to{opacity:1;transform:none}}
}

/* Khoá cỡ chữ: trình duyệt điện thoại tự phóng to chữ trong khối văn bản dài,
   làm mỗi dòng còn hơn hai chục ký tự và màn dài gấp đôi. */
html{-webkit-text-size-adjust:100%;text-size-adjust:100%}
.wrap{max-width:30rem;margin:0 auto;padding:2.5rem 1rem}
h1{font-size:1.35rem;margin:.2rem 0 .3rem}
h2{font-size:1rem;margin:0 0 .2rem;letter-spacing:normal;text-transform:none;color:var(--ink)}
.brand{font-size:.78rem;letter-spacing:.09em;text-transform:uppercase;color:var(--muted)}
.sub{color:var(--muted);font-size:.9rem;margin:0 0 1.3rem;line-height:1.55}
label{display:block;font-size:.8rem;color:var(--muted);margin:.9rem 0 .3rem}
input,select{font:inherit;width:100%;padding:.6rem .7rem;border-radius:.55rem;
border:1px solid var(--line);background:var(--card);color:var(--ink)}
input:focus,select:focus{outline:2px solid var(--accent);outline-offset:1px}
input.code{font-family:ui-monospace,Menlo,monospace;font-size:1.5rem;letter-spacing:.4em;
text-align:center;padding:.7rem .3rem}
button{font:inherit;font-weight:600;width:100%;margin-top:1.1rem;padding:.65rem;
border-radius:.55rem;border:1px solid var(--accent);background:var(--accent);
color:#fff;cursor:pointer}
button.ghost{background:transparent;color:var(--ink);border-color:var(--line)}
button.danger{background:transparent;color:var(--warn);border-color:var(--warn)}
.err{background:var(--warn-soft);color:var(--warn);border:1px solid var(--warn);
border-radius:.55rem;padding:.6rem .8rem;font-size:.88rem;margin-bottom:1rem}
.ok{background:var(--accent-soft);color:var(--accent);border:1px solid var(--accent);
border-radius:.55rem;padding:.6rem .8rem;font-size:.88rem;margin-bottom:1rem}
.card{border:1px solid var(--line);background:var(--card);border-radius:.7rem;
padding:1.1rem 1.2rem;margin-bottom:1.2rem}
.qr{display:flex;justify-content:center;margin:1rem 0}
.qr svg{width:min(15rem,60vw);height:auto;border:1px solid var(--line);border-radius:.5rem}
.manual{margin-top:.8rem;font-size:.88rem}
.manual summary{cursor:pointer;color:var(--accent);font-weight:600}
.key{font-family:ui-monospace,Menlo,monospace;font-size:1.05rem;letter-spacing:.14em;
word-break:break-all;background:var(--bg);border:1px solid var(--line);
border-radius:.5rem;padding:.7rem .8rem;margin:.6rem 0;text-align:center}
.steps{font-size:.85rem;color:var(--muted);line-height:1.75;padding-left:1.1rem;margin:.5rem 0}
ol.codes{list-style:none;padding:0;margin:.6rem 0;display:grid;
grid-template-columns:repeat(2,1fr);gap:.4rem}
ol.codes li{font-family:ui-monospace,Menlo,monospace;background:var(--bg);
border:1px solid var(--line);border-radius:.4rem;padding:.45rem;text-align:center;font-size:.95rem}
.note{font-size:.82rem;color:var(--muted);line-height:1.6;margin:.6rem 0 0}
.badge{display:inline-block;font-size:.72rem;padding:.15rem .5rem;border-radius:1rem;
border:1px solid var(--line);color:var(--muted)}
.badge.on{color:var(--accent);border-color:var(--accent);background:var(--accent-soft)}
.badge.off{color:var(--warn);border-color:var(--warn);background:var(--warn-soft)}
a.back{font-size:.85rem;color:var(--muted);text-decoration:none}
a.link{color:var(--accent)}