/* OctaX.vn — bản demo giao diện. Hai bộ màu tối/sáng dùng chung biến CSS, đổi bằng thuộc tính data-theme trên <html>.
   Bộ nhận diện lấy đúng theo logo /img/logo/octax-*.svg và trang đăng nhập nền tảng (auth/login.html):
   font Space Grotesk · xanh não #1E3A8A · xanh sáng #3B82F6 / #2563EB · cam năng lượng #F97316 / #EA580C · nền slate #0F172A. */
/* Font Space Grotesk nạp bằng <link> trong <head> (preconnect) thay cho @import: không chặn hiển thị trang. */
:root,[data-theme="dark"]{
  --bg:#0b1120; --bg2:#0f172a; --card:#131d33; --card2:#1a2642; --line:#25324f;
  --text:#e8edf7; --muted:#94a3b8; --brand:#3b82f6; --brand2:#f97316; --ok:#22c55e; --warn:#facc15; --bad:#ef4444;
  --logo-text:#ffffff;
  --glow:0 0 0 1px rgba(59,130,246,.35),0 10px 40px -10px rgba(37,99,235,.5);
  /* Dải màu như cánh logo: xanh não → xanh sáng → cam */
  --grad:linear-gradient(120deg,#2563eb 0%,#3b82f6 45%,#f97316 100%);
  --grad-btn:linear-gradient(135deg,#2563eb 0%,#1e3a8a 100%);
  --grad-text:linear-gradient(90deg,#60a5fa 0%,#f97316 100%);
  --hero:radial-gradient(60% 50% at 50% 0%,rgba(37,99,235,.38) 0%,rgba(11,17,32,0) 70%),radial-gradient(40% 40% at 85% 20%,rgba(249,115,22,.16) 0%,rgba(11,17,32,0) 70%);
}
[data-theme="light"]{
  --bg:#f8fafc; --bg2:#eef2f7; --card:#ffffff; --card2:#f1f5f9; --line:#e2e8f0;
  --text:#0f172a; --muted:#64748b; --brand:#1e3a8a; --brand2:#ea580c; --warn:#ca8a04;
  --logo-text:#1e3a8a;
  --glow:0 0 0 1px rgba(30,58,138,.18),0 10px 30px -12px rgba(30,58,138,.35);
  --grad-text:linear-gradient(90deg,#1e3a8a 0%,#2563eb 45%,#ea580c 100%);
  --hero:radial-gradient(60% 50% at 50% 0%,rgba(59,130,246,.16) 0%,rgba(248,250,252,0) 70%),radial-gradient(40% 40% at 85% 20%,rgba(249,115,22,.12) 0%,rgba(248,250,252,0) 70%);
}
*{box-sizing:border-box}
html,body{margin:0;color:var(--text);font:15px/1.6 "Space Grotesk",var(--ff-x),"Segoe UI",system-ui,sans-serif}
/* Màu nền đặt ở <html>; <body> trong suốt để nền động (canvas.ox-bg) hiện phía sau nội dung */
html{background:var(--bg)} body{background:transparent;min-height:100vh}
h1,h2,h3,.stat,.kpi .v,.price .amt{font-family:"Space Grotesk",var(--ff-x),"Segoe UI",sans-serif}
a{color:inherit;text-decoration:none}
.wrap{max-width:1180px;margin:0 auto;padding:0 20px}
.muted{color:var(--muted)} .small{font-size:13px} .center{text-align:center}
.grad-text{background:var(--grad-text);-webkit-background-clip:text;background-clip:text;color:transparent}

/* Thanh menu */
.nav{position:sticky;top:0;z-index:50;backdrop-filter:blur(14px);background:color-mix(in srgb,var(--bg) 78%,transparent);border-bottom:1px solid var(--line)}
.nav .wrap{display:flex;align-items:center;gap:28px;height:64px}
/* Logo: biểu tượng tám cánh octax-icon.svg + chữ "OctaX" (X màu cam) như octax-horizontal-*.svg */
.logo{display:flex;align-items:center;gap:6px;font-weight:700;font-size:22px;letter-spacing:-.03em;color:var(--logo-text)}
.logo img{width:40px;height:40px;margin:-4px -2px -4px -6px}
.logo b{color:#f97316;font-weight:800;font-size:1.1em}
.logo small{color:var(--muted);font-weight:600;font-size:.72em;letter-spacing:0;margin-left:1px}
.nav .links{display:flex;gap:22px;flex:1}
.nav .links a{color:var(--muted);font-weight:500}
.nav .links a:hover,.nav .links a.on{color:var(--text)}
.nav .act{display:flex;gap:10px;align-items:center}
.demo-bar{background:linear-gradient(90deg,#1e3a8a,#2563eb 60%,#ea580c);color:#fff;font-size:12.5px;text-align:center;padding:5px 10px}
.demo-bar a{text-decoration:underline;margin:0 6px}

/* Nút */
.btn{display:inline-flex;align-items:center;gap:8px;border:1px solid var(--line);background:var(--card);color:var(--text);padding:9px 16px;border-radius:10px;font-weight:600;cursor:pointer;font-size:14px;transition:.15s}
.btn:hover{border-color:var(--brand)}
.btn.pri{background:var(--grad-btn);border:0;color:#fff;box-shadow:var(--glow)}
.btn.cta{background:linear-gradient(135deg,#f97316,#ea580c);border:0;color:#fff;box-shadow:0 10px 30px -10px rgba(234,88,12,.6)}
.btn.cta:hover{filter:brightness(1.08)}
.btn.pri:hover{filter:brightness(1.1)}
.btn.sm{padding:6px 11px;font-size:13px;border-radius:8px}
.btn.ghost{background:transparent}
.btn.bad{border-color:var(--bad);color:var(--bad);background:transparent}
.icon-btn{width:38px;height:38px;justify-content:center;padding:0}

/* Phần đầu trang */
.hero{background:var(--hero);padding:84px 0 60px;text-align:center}
.hero h1{font-size:clamp(34px,5.4vw,62px);line-height:1.08;letter-spacing:-.035em;margin:18px 0 16px}
.hero p.lead{font-size:18px;color:var(--muted);max-width:720px;margin:0 auto 30px}
.pill{display:inline-flex;gap:8px;align-items:center;border:1px solid var(--line);background:var(--card);padding:5px 12px;border-radius:99px;font-size:13px;color:var(--muted)}
.pill b{color:var(--brand2)}
.try{max-width:760px;margin:0 auto;background:var(--card);border:1px solid var(--line);border-radius:18px;padding:10px;box-shadow:var(--glow);text-align:left}
.try textarea{width:100%;min-height:74px;border:0;outline:0;resize:none;background:transparent;color:var(--text);font:inherit;font-size:16px;padding:10px 12px}
.try .row{display:flex;justify-content:space-between;align-items:center;gap:10px;padding:4px 6px}
.chips{display:flex;gap:8px;flex-wrap:wrap}
.chip{font-size:12.5px;border:1px solid var(--line);border-radius:99px;padding:4px 10px;color:var(--muted);cursor:pointer;background:var(--card2)}
.chip:hover{color:var(--text);border-color:var(--brand)}
.try-out{max-width:760px;margin:18px auto 0;text-align:left;display:none}
.try-out.show{display:block}

/* Khối nội dung */
section{padding:70px 0}
.sec-h{text-align:center;margin-bottom:38px}
.sec-h h2{font-size:clamp(26px,3.4vw,40px);letter-spacing:-.025em;margin:6px 0 10px}
.sec-h p{color:var(--muted);max-width:640px;margin:0 auto}
.eyebrow{color:var(--brand2);font-weight:700;font-size:12.5px;letter-spacing:.12em;text-transform:uppercase}
.grid{display:grid;gap:18px}
.g2{grid-template-columns:repeat(2,1fr)} .g3{grid-template-columns:repeat(3,1fr)} .g4{grid-template-columns:repeat(4,1fr)}
@media(max-width:960px){.g3,.g4{grid-template-columns:repeat(2,1fr)} .nav .links{display:none}}
@media(max-width:620px){.g2,.g3,.g4{grid-template-columns:1fr}}
.card{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:22px}
.card h3{margin:0 0 6px;font-size:18px}
.card.hov{transition:.2s} .card.hov:hover{transform:translateY(-3px);box-shadow:var(--glow);border-color:transparent}
.sol .ico{width:44px;height:44px;border-radius:12px;display:grid;place-items:center;font-size:22px;background:var(--card2);margin-bottom:14px}
.sol ul{padding-left:18px;margin:10px 0 0;color:var(--muted);font-size:14px}
.logos{display:flex;gap:34px;justify-content:center;flex-wrap:wrap;opacity:.75;font-weight:700;color:var(--muted);letter-spacing:.04em}
.stat{font-size:34px;font-weight:800;letter-spacing:-.03em}

/* Mô hình 3D */
.viewer{height:340px;border-radius:16px;background:var(--card2);border:1px solid var(--line);overflow:hidden}
model-viewer{width:100%;height:100%;--poster-color:transparent}

/* Bảng giá */
.toggle{display:inline-flex;border:1px solid var(--line);border-radius:12px;padding:4px;background:var(--card);gap:4px}
.toggle button{border:0;background:transparent;color:var(--muted);padding:8px 16px;border-radius:9px;font-weight:600;cursor:pointer;font:inherit}
.toggle button.on{background:var(--grad-btn);color:#fff}
.tabs-row{display:flex;gap:14px;justify-content:center;flex-wrap:wrap;margin-bottom:30px}
.price{position:relative;display:flex;flex-direction:column}
.price.hot{border-color:transparent;box-shadow:var(--glow)}
.price .badge{position:absolute;top:-11px;right:18px}
.price .amt{font-size:32px;font-weight:800;letter-spacing:-.03em;margin:10px 0 0}
.price .amt small{display:block;font-size:13px;color:var(--muted);font-weight:500;letter-spacing:0}
.price ul{list-style:none;padding:0;margin:16px 0 20px;flex:1}
.price li{padding:5px 0 5px 24px;position:relative;font-size:14px}
.price li:before{content:"✓";position:absolute;left:0;color:var(--ok);font-weight:800}
.tax{font-size:12.5px;color:var(--muted);border-top:1px dashed var(--line);padding-top:8px;margin-top:6px}
.badge{display:inline-block;font-size:11.5px;font-weight:700;padding:3px 9px;border-radius:99px;background:#ea580c;color:#fff}
.tag{display:inline-block;font-size:11.5px;font-weight:600;padding:2px 8px;border-radius:6px;border:1px solid var(--line);background:var(--card2);color:var(--muted)}
.tag.ok{color:var(--ok);border-color:color-mix(in srgb,var(--ok) 45%,transparent)}
.tag.warn{color:var(--warn);border-color:color-mix(in srgb,var(--warn) 45%,transparent)}
.tag.bad{color:var(--bad);border-color:color-mix(in srgb,var(--bad) 45%,transparent)}
.tag.kct{color:var(--brand);border-color:color-mix(in srgb,var(--brand) 45%,transparent)}

/* Bảng dữ liệu */
table.t{width:100%;border-collapse:collapse;font-size:14px}
table.t th,table.t td{padding:10px 12px;border-bottom:1px solid var(--line);text-align:left;vertical-align:top}
table.t th{color:var(--muted);font-weight:600;font-size:12.5px;text-transform:uppercase;letter-spacing:.04em}
table.t td.n,table.t th.n{text-align:right;font-variant-numeric:tabular-nums}
table.t tr:hover td{background:color-mix(in srgb,var(--card2) 60%,transparent)}
table.t tfoot td{font-weight:700}

/* FAQ */
details{border:1px solid var(--line);border-radius:12px;padding:14px 18px;background:var(--card);margin-bottom:10px}
details summary{cursor:pointer;font-weight:600}
details p{color:var(--muted);margin:10px 0 0}

/* Hộp thoại */
.modal{position:fixed;inset:0;background:rgba(0,0,0,.55);display:none;align-items:center;justify-content:center;z-index:100;padding:20px}
.modal.show{display:flex}
.modal .box{background:var(--card);border:1px solid var(--line);border-radius:18px;max-width:620px;width:100%;max-height:92vh;overflow:auto;padding:24px}
.modal h3{margin-top:0}
input.f,select.f{width:100%;padding:10px 12px;border-radius:10px;border:1px solid var(--line);background:var(--bg2);color:var(--text);font:inherit}
label.lb{display:block;font-size:13px;color:var(--muted);margin:12px 0 5px}
.qr{width:180px;height:180px;border-radius:12px;background:#fff;padding:10px;display:grid;grid-template-columns:repeat(21,1fr)}
.qr span{background:#fff} .qr span.b{background:#000}

/* Bố cục cổng quản trị */
.app{display:grid;grid-template-columns:230px 1fr;min-height:calc(100vh - 92px)}
.side{border-right:1px solid var(--line);padding:18px 12px;background:var(--bg2)}
.side a{display:flex;gap:10px;align-items:center;padding:9px 12px;border-radius:9px;color:var(--muted);font-weight:500;font-size:14px;cursor:pointer}
.side a.on,.side a:hover{background:var(--card);color:var(--text)}
.side .grp{font-size:11px;letter-spacing:.1em;text-transform:uppercase;color:var(--muted);margin:16px 12px 6px}
.main{padding:26px 30px;overflow:auto}
.main h1{font-size:24px;margin:0 0 4px;letter-spacing:-.02em}
.kpi .v{font-size:26px;font-weight:800;letter-spacing:-.02em}
.kpi .l{color:var(--muted);font-size:13px}
.bar{height:8px;border-radius:99px;background:var(--card2);overflow:hidden}
.bar i{display:block;height:100%;background:var(--grad)}
.toolbar{display:flex;gap:10px;align-items:center;justify-content:space-between;margin:18px 0 12px;flex-wrap:wrap}
.note{border-left:3px solid var(--warn);background:color-mix(in srgb,var(--warn) 9%,transparent);padding:10px 14px;border-radius:8px;font-size:13.5px;margin:12px 0}
.note.info{border-color:var(--brand);background:color-mix(in srgb,var(--brand) 9%,transparent)}
pre.code{background:var(--bg2);border:1px solid var(--line);border-radius:10px;padding:12px;font-size:12.5px;overflow:auto}
.toast{position:fixed;bottom:20px;right:20px;background:var(--card);border:1px solid var(--line);box-shadow:var(--glow);border-radius:12px;padding:12px 16px;z-index:200;display:none;max-width:380px}
.toast.show{display:block}
@media(max-width:820px){.app{grid-template-columns:1fr}.side{display:flex;overflow:auto;gap:4px}.side .grp{display:none}}

/* Chân trang */
footer{border-top:1px solid var(--line);padding:46px 0 30px;margin-top:40px;background:var(--bg2)}
footer .cols{display:grid;grid-template-columns:2fr 1fr 1fr 1fr;gap:24px}
footer h4,footer .h4{margin:0 0 10px;font-size:14px}
footer a{display:block;color:var(--muted);font-size:14px;padding:3px 0}
@media(max-width:720px){footer .cols{grid-template-columns:1fr 1fr}}

/* Ảnh chụp giao diện làm việc thật (img/giao-dien/) — bấm để phóng to */
.shots{display:grid;gap:18px;grid-template-columns:repeat(6,1fr)}
.shot{margin:0;background:var(--card);border:1px solid var(--line);border-radius:16px;overflow:hidden;cursor:zoom-in;transition:.2s;display:flex;flex-direction:column}
.shot:hover{transform:translateY(-3px);box-shadow:var(--glow);border-color:transparent}
.shot img{display:block;width:100%;aspect-ratio:16/10;object-fit:cover;object-position:top left;border-bottom:1px solid var(--line);background:var(--card2)}
/* .fill: ảnh giãn kín chiều cao ô khi đứng cạnh ô rộng hơn (vd ảnh điện thoại cạnh ảnh bảng lương) */
.shot.fill img{aspect-ratio:auto;flex:1 1 0;height:0;min-height:240px;object-position:top center}
.shot figcaption{padding:12px 14px;font-size:13.5px}
.shot figcaption b{display:block;font-size:14.5px;margin-bottom:2px}
.shots .w2{grid-column:span 2} .shots .w3{grid-column:span 3} .shots .w4{grid-column:span 4}
.shots .r2{grid-row:span 2}
@media(max-width:960px){.shots{grid-template-columns:repeat(2,1fr)} .shots .w2,.shots .w3,.shots .w4{grid-column:span 1} .shots .r2{grid-row:auto}}
@media(max-width:620px){.shots{grid-template-columns:1fr}}
.frame{border-radius:16px;overflow:hidden;border:1px solid var(--line);box-shadow:var(--glow);background:var(--card2);cursor:zoom-in}
.frame img{display:block;width:100%}
.frame .bar-top{display:flex;gap:6px;padding:8px 12px;background:var(--bg2);border-bottom:1px solid var(--line)}
.frame .bar-top i{width:10px;height:10px;border-radius:50%;background:var(--line)}
.frame .bar-top i:nth-child(1){background:#ef4444}.frame .bar-top i:nth-child(2){background:#facc15}.frame .bar-top i:nth-child(3){background:#22c55e}
.lightbox{position:fixed;inset:0;z-index:300;background:rgba(2,6,23,.88);display:none;align-items:center;justify-content:center;padding:24px;flex-direction:column;gap:12px;cursor:zoom-out}
.lightbox.show{display:flex}
.lightbox img{max-width:min(1400px,96vw);max-height:84vh;border-radius:12px;box-shadow:0 20px 60px rgba(0,0,0,.6)}
.lightbox p{color:#e2e8f0;margin:0;font-size:14px;text-align:center;max-width:900px}

/* ===== Nền động (js/octax-bg.js) ===== */
canvas.ox-bg{position:fixed;inset:0;width:100vw;height:100vh;z-index:-1;pointer-events:none;opacity:.95}
[data-theme="light"] canvas.ox-bg{opacity:.85}
/* Cực quang vẽ ở độ phân giải thấp → làm nhoè trên card đồ hoạ cho mềm như ánh sáng thật */
html[data-bg="cuc-quang"] canvas.ox-bg{filter:blur(10px);transform:scale(1.04)}
/* Nền động đang bật → nền đầu trang/ thẻ hơi trong để thấy chiều sâu, chữ vẫn đủ tương phản */
html:not([data-bg="tat"]) .card,html:not([data-bg="tat"]) details,html:not([data-bg="tat"]) .shot{background:color-mix(in srgb,var(--card) 90%,transparent)}
html:not([data-bg="tat"]) footer{background:color-mix(in srgb,var(--bg2) 94%,transparent)}
.bg-menu{position:relative}
.bg-menu [role=menu]{position:absolute;right:0;top:46px;min-width:220px;background:var(--card);border:1px solid var(--line);border-radius:12px;padding:6px;box-shadow:var(--glow);z-index:60}
.bg-menu [role=menu] button{display:flex;flex-direction:column;align-items:flex-start;width:100%;border:0;background:transparent;color:var(--text);font:inherit;font-size:14px;padding:8px 10px;border-radius:8px;cursor:pointer;text-align:left}
.bg-menu [role=menu] button:hover{background:var(--card2)}
.bg-menu [role=menu] button[aria-checked=true]{background:color-mix(in srgb,var(--brand) 18%,transparent);font-weight:600}
.bg-menu [role=menu] small{color:var(--muted);font-size:11.5px;font-weight:400}
.nav .links a{white-space:nowrap}
.nav .links{gap:18px}
@media(max-width:1100px){.nav .links{gap:12px;font-size:14px}}

/* Đường dẫn vị trí (breadcrumb) — cũng khai báo BreadcrumbList cho Google */
.crumbs{font-size:13px;color:var(--muted);margin:18px 0 0}
.crumbs a:hover{color:var(--text)} .crumbs span{margin:0 6px;opacity:.6}

/* ===== Kho mẫu ===== */
.loc{display:flex;gap:8px;flex-wrap:wrap;justify-content:center;margin:0 0 14px}
.loc button{border:1px solid var(--line);background:var(--card);color:var(--muted);padding:7px 14px;border-radius:99px;font:inherit;font-size:13.5px;font-weight:600;cursor:pointer}
.loc button.on,.loc button:hover{color:var(--text);border-color:var(--brand)}
.loc button.on{background:var(--grad-btn);color:#fff;border-color:transparent}
.tim{max-width:560px;margin:0 auto 26px;display:flex;gap:8px}
.mau{display:flex;flex-direction:column;padding:0;overflow:hidden}
.mau .anh{display:block;aspect-ratio:16/10;background:var(--card2);border-bottom:1px solid var(--line);overflow:hidden}
.mau .anh img{width:100%;height:100%;object-fit:cover;display:block;transition:.3s}
.mau:hover .anh img{transform:scale(1.03)}
.mau .nd{padding:14px 16px 16px;display:flex;flex-direction:column;gap:6px;flex:1}
.mau h3{font-size:16px;margin:0}
.mau p{margin:0;font-size:13.5px;color:var(--muted);flex:1}
.mau .meta{display:flex;gap:6px;flex-wrap:wrap}
.tag.free{color:#fff;background:#16a34a;border-color:transparent}
.dm-dem{display:grid;grid-template-columns:repeat(7,1fr);gap:10px;margin:26px 0 8px}
.dm-dem a{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:12px;text-align:center;font-size:13px;color:var(--muted)}
.dm-dem a b{display:block;font-size:22px;color:var(--text)}
.dm-dem a:hover{border-color:var(--brand)}
@media(max-width:960px){.dm-dem{grid-template-columns:repeat(4,1fr)}}
@media(max-width:620px){.dm-dem{grid-template-columns:repeat(2,1fr)}}
.ct{display:grid;grid-template-columns:1.35fr 1fr;gap:26px;align-items:start}
@media(max-width:900px){.ct{grid-template-columns:1fr}}
.ct .xem{border-radius:16px;overflow:hidden;border:1px solid var(--line);background:var(--card2)}
.ct .xem img{display:block;width:100%}
.ct .xem model-viewer{height:420px}
.ct .xem iframe{display:block;width:100%;height:460px;border:0;background:#fff}
.tep{list-style:none;padding:0;margin:10px 0}
.tep li{display:flex;justify-content:space-between;gap:10px;align-items:center;padding:9px 0;border-bottom:1px solid var(--line);font-size:14px}
.bai h2{font-size:22px;margin:28px 0 8px;letter-spacing:-.02em}
.bai p,.bai li{color:var(--muted)}
.bai ol li,.bai ul li{margin:4px 0}
pre.code code{white-space:pre}

/* ===== Công cụ & Trải nghiệm ===== */
.cc{display:grid;grid-template-columns:repeat(2,1fr);gap:12px}
.cc label.lb{margin-top:6px}
.kq{margin-top:14px;padding:12px 14px;border-radius:12px;background:var(--card2);border:1px solid var(--line);font-size:14px}
.kq b.lon{font-size:22px;display:block;letter-spacing:-.02em}
.nen-o{display:grid;grid-template-columns:repeat(4,1fr);gap:12px}
.nen-o button{border:1px solid var(--line);background:var(--card);color:var(--text);border-radius:14px;padding:16px 10px;font:inherit;font-weight:600;cursor:pointer}
.nen-o button span{display:block;font-size:28px;margin-bottom:4px}
.nen-o button:hover{border-color:var(--brand);box-shadow:var(--glow)}
@media(max-width:620px){.nen-o{grid-template-columns:repeat(2,1fr)} .cc{grid-template-columns:1fr}}
.thiet-bi{display:inline-flex;gap:4px}
.khung-web{margin:0 auto;transition:width .25s;border-radius:14px;overflow:hidden;border:1px solid var(--line);box-shadow:var(--glow);background:#fff}
.khung-web iframe{display:block;width:100%;height:560px;border:0}
.drop{border:2px dashed var(--line);border-radius:14px;padding:22px;text-align:center;color:var(--muted);cursor:pointer}
.drop.keo{border-color:var(--brand);color:var(--text)}

/* Điện thoại: menu gọn (ẩn "Đăng nhập" — vẫn có trong chân trang/cổng khách), không để trang tràn ngang */
@media(max-width:620px){
  .nav .wrap{gap:10px} .nav .act{gap:6px;margin-left:auto}
  .nav .act a.btn.ghost{display:none}
  .nav .act .btn.cta{padding:6px 10px;font-size:12.5px;white-space:nowrap}
  .logo{font-size:19px} .logo img{width:34px;height:34px}
  .icon-btn{width:34px;height:34px}
  .demo-bar{font-size:11px}
  .hero{padding-left:0;padding-right:0}
  .toolbar .toggle{flex-wrap:wrap}
}
body{overflow-x:clip}
@media(max-width:620px){.ct .xem model-viewer{height:300px} .ct .xem iframe{height:380px} .khung-web iframe{height:460px}}

/* ---------- Đa ngôn ngữ ---------- */
/* Space Grotesk không có chữ Thái/Khmer/Lào/Myanmar ⇒ trình duyệt lấy ký tự đó từ font Noto tương ứng (nạp riêng ở trang ngôn ngữ đó) */
:root{--ff-x:"Segoe UI"}
html[lang=th]{--ff-x:"Noto Sans Thai"} html[lang=km]{--ff-x:"Noto Sans Khmer"} html[lang=lo]{--ff-x:"Noto Sans Lao"} html[lang=my]{--ff-x:"Noto Sans Myanmar"}
html[lang=km] body,html[lang=my] body,html[lang=lo] body{line-height:1.85}
html[lang=th] .eyebrow,html[lang=km] .eyebrow,html[lang=lo] .eyebrow,html[lang=my] .eyebrow{letter-spacing:0}
html[lang=my] h1,html[lang=km] h1{line-height:1.35}
.lang-menu{position:relative}
.lang-menu [data-lang-nut]{white-space:nowrap;font-weight:600}
.lang-menu [role=menu]{position:absolute;right:0;top:46px;min-width:200px;background:var(--card);border:1px solid var(--line);border-radius:12px;padding:6px;box-shadow:var(--glow);z-index:60}
.lang-menu [role=menu] a{display:block;padding:8px 12px;border-radius:8px;color:var(--text);font-size:14px}
.lang-menu [role=menu] a:hover{background:var(--card2)}
.lang-menu [role=menu] a[aria-current]{background:color-mix(in srgb,var(--brand) 18%,transparent);font-weight:600}
.lang-bar{display:flex;align-items:center;justify-content:center;gap:12px;padding:8px 14px;background:var(--card);border-bottom:1px solid var(--line);font-size:14px;position:relative;z-index:51}
.lang-bar a{color:var(--text)} .lang-bar a b{color:var(--brand2)}
.lang-bar button{border:0;background:transparent;color:var(--muted);font-size:20px;line-height:1;cursor:pointer;padding:0 6px}
footer .langs{margin:26px 0 0;color:var(--muted);line-height:2}
footer .langs a{display:inline;margin:0 2px}
/* Ghi chú chỉ hiện ở bản ngôn ngữ khác tiếng Việt (vd tiền tệ, hoá đơn Việt Nam) */
.chi-ngoai{display:none} html:not([lang=vi]) .chi-ngoai{display:block}
@media(max-width:640px){.lang-menu [data-lang-nut]{padding:6px 8px}}
/* ---------- Video thao tác ---------- */
.vids{align-items:start}
.vid{padding:0;overflow:hidden;margin:0}
.vid video{display:block;width:100%;height:auto;aspect-ratio:16/9;background:#0b1120}
.vid figcaption{padding:12px 16px 14px} .vid h3{margin:0 0 4px;font-size:17px} .vid p{margin:0}
/* Thanh menu: thêm nút ngôn ngữ + chữ dịch dài hơn ⇒ không cho nút xuống dòng, thu gọn dần theo bề ngang */
.nav .act .btn{white-space:nowrap}
.nav .links a{white-space:nowrap}
@media(max-width:1440px){.nav .wrap{gap:18px} .nav .links{gap:14px;font-size:14.5px} .nav .act a.btn.ghost{display:none}}
@media(max-width:1200px){.nav .links{gap:10px;font-size:13.5px} .nav .act{gap:6px}}
@media(max-width:1100px){.nav .links{display:none}}
.try .btn{white-space:nowrap}

/* ---------- Bản thật / bản demo (tools/xay_dung.py --xuat-that gắn data-che-do="that" vào <html>) ---------- */
html[data-che-do="that"] [data-demo]{display:none!important}
html:not([data-che-do="that"]) [data-that]{display:none!important}
/* Form đăng ký (js/octax-dang-ky.js) */
.dk-grid{display:grid;grid-template-columns:1fr 1fr;gap:0 14px}
@media(max-width:600px){.dk-grid{grid-template-columns:1fr}}
textarea.f{width:100%;padding:10px 12px;border-radius:10px;border:1px solid var(--line);background:var(--bg2);color:var(--text);font:inherit;resize:vertical}
.dk-hp{position:absolute;left:-5000px;width:1px;height:1px;overflow:hidden}