/* Trang giới thiệu (xsmartlink.vn) – màu chủ đạo lấy từ /brand.css (Quản trị › Thương hiệu) */
:root {
  --bg: #F6F8FC; --bg2: #EDF2FA; --surface: #FFFFFF; --ink: #0A1530; --muted: #56627C; --line: #DCE3EE;
  --brand: #0A5BFF; --brand2: #00C6F5; --grad: linear-gradient(135deg, #00D2FF 0%, #0A5BFF 55%, #0A3DFF 100%);
  --on: #1569FF; --on-soft: #E3EEFF; --on-ink: #0A3A99; --glow: rgba(21, 105, 255, .32);
  --r: 20px; --shadow: 0 1px 2px rgba(10, 21, 48, .05), 0 10px 30px rgba(10, 21, 48, .07);
  --font: "Be Vietnam Pro", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #060C1A; --bg2: #0B1426; --surface: #0E1830; --ink: #E8EEFA; --muted: #93A0BC; --line: #1E2C4A; --on: #3D8BFF; --on-soft: #12264D; --on-ink: #BBD3FF; --shadow: none; }
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 400 17px/1.65 var(--font); -webkit-font-smoothing: antialiased; }
img { max-width: 100%; height: auto; display: block; }
a { color: var(--on); text-decoration-thickness: 1px; text-underline-offset: 3px; }
h1, h2, h3 { line-height: 1.2; letter-spacing: -0.015em; margin: 0 0 .5em; text-wrap: balance; }
h1 { font-size: clamp(32px, 5.2vw, 54px); font-weight: 800; }
h2 { font-size: clamp(26px, 3.6vw, 38px); font-weight: 800; }
h3 { font-size: 19px; font-weight: 700; }
p { margin: 0 0 1em; }
.w { max-width: 1160px; margin: 0 auto; padding: 0 20px; }
.w.narrow { max-width: 780px; }
.lead { font-size: clamp(17px, 2vw, 20px); color: var(--muted); max-width: 760px; }
.mut { color: var(--muted); } .sm { font-size: 14px; }
.ic { width: 24px; height: 24px; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; flex: none; }
.ic.big { width: 34px; height: 34px; }
.skip { position: absolute; left: -999px; top: 8px; background: var(--surface); padding: 8px 14px; border-radius: 10px; z-index: 50; }
.skip:focus { left: 12px; }
:focus-visible { outline: 3px solid var(--brand2); outline-offset: 2px; }

/* nút */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; min-height: 48px; padding: 0 22px; border-radius: 999px; background: var(--grad); color: #fff; font-weight: 600; text-decoration: none; border: 1px solid transparent; box-shadow: 0 8px 20px -8px var(--glow); transition: transform .15s, box-shadow .15s; white-space: nowrap; }
.btn:hover { transform: translateY(-1px); box-shadow: 0 12px 26px -8px var(--glow); }
.btn.ghost { background: var(--surface); color: var(--ink); border-color: var(--line); box-shadow: none; }
.btn.ghost.light { background: rgba(255, 255, 255, .14); color: #fff; border-color: rgba(255, 255, 255, .4); }
.btn.sm { min-height: 40px; padding: 0 16px; font-size: 15px; }
.btns { display: flex; flex-wrap: wrap; gap: 12px; margin: 24px 0 8px; }
.btns.c { justify-content: center; }
.badge { display: inline-block; padding: 4px 12px; border-radius: 999px; background: var(--on-soft); color: var(--on-ink); font-size: 13px; font-weight: 600; margin-bottom: 14px; }

/* đầu trang */
.hd { position: sticky; top: 0; z-index: 20; background: color-mix(in srgb, var(--bg) 82%, transparent); backdrop-filter: saturate(1.6) blur(14px); -webkit-backdrop-filter: saturate(1.6) blur(14px); border-bottom: 1px solid color-mix(in srgb, var(--line) 70%, transparent); }
.hd .w { display: flex; align-items: center; gap: 20px; min-height: 68px; }
.logo { display: flex; align-items: center; gap: 10px; text-decoration: none; color: var(--ink); margin-right: auto; min-width: 0; }
.logo img { width: 40px; height: 40px; }
.logo b { display: block; font-size: 17px; line-height: 1.2; }
.logo small { display: block; font-size: 12px; font-weight: 600; background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.nav { display: flex; gap: 6px; }
.nav a { color: var(--ink); text-decoration: none; padding: 8px 12px; border-radius: 10px; font-weight: 500; font-size: 15.5px; }
.nav a:hover { background: var(--bg2); }
.mnav { display: none; position: relative; }
.mnav summary { list-style: none; cursor: pointer; width: 44px; height: 44px; display: grid; place-content: center; gap: 5px; border-radius: 12px; border: 1px solid var(--line); background: var(--surface); }
.mnav summary::-webkit-details-marker { display: none; }
.mnav summary span { display: block; width: 18px; height: 2px; background: var(--ink); border-radius: 2px; }
.mnav nav { position: absolute; right: 0; top: 52px; background: var(--surface); border: 1px solid var(--line); border-radius: 16px; padding: 8px; min-width: 220px; display: grid; gap: 2px; box-shadow: 0 20px 40px rgba(10, 21, 48, .18); }
.mnav nav a { padding: 12px 14px; border-radius: 10px; color: var(--ink); text-decoration: none; font-weight: 500; }
.mnav nav a.btn { color: #fff; margin-top: 6px; }
@media (max-width: 860px) { .nav, .hd .app { display: none; } .mnav { display: block; } }

/* mục */
.sec { padding: clamp(56px, 8vw, 96px) 0; }
.sec.alt { background: var(--bg2); }
.sec.top { padding-top: 40px; }
.sec h2 + .lead { margin-top: -4px; }
.grid { display: grid; gap: 20px; margin-top: 32px; }
.g3 { grid-template-columns: repeat(auto-fill, minmax(min(100%, 300px), 1fr)); }
.card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--r); box-shadow: var(--shadow); }
.card.f, .card.u { padding: 26px; }
.card.f .ic { width: 46px; height: 46px; padding: 11px; border-radius: 14px; background: var(--grad); color: #fff; margin-bottom: 16px; }
.card.u .ic { color: var(--on); margin-bottom: 12px; }
.card p { color: var(--muted); margin: 0; }

/* hero */
.hero { padding: clamp(36px, 6vw, 72px) 0 clamp(40px, 6vw, 80px); overflow: hidden; background: radial-gradient(900px 500px at 85% 10%, color-mix(in srgb, var(--brand2) 18%, transparent), transparent 70%), radial-gradient(700px 400px at 0% 100%, color-mix(in srgb, var(--brand) 10%, transparent), transparent 70%); }
.hero-g { display: grid; grid-template-columns: 1.05fr .95fr; gap: 40px; align-items: center; }
.hero h1 { background: linear-gradient(180deg, var(--ink), color-mix(in srgb, var(--ink) 70%, var(--brand))); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero-i img { width: 100%; max-width: 560px; margin: 0 auto; }
@media (max-width: 860px) { .hero-g { grid-template-columns: 1fr; } .hero-i { order: -1; } .hero-i img { max-width: 420px; } }

/* sản phẩm */
.card.p { overflow: hidden; display: flex; flex-direction: column; }
.card.p img { aspect-ratio: 4 / 3; object-fit: cover; width: 100%; background: var(--bg2); }
.p-b { padding: 20px 22px 22px; display: flex; flex-direction: column; flex: 1; }
.p-b .badge { align-self: flex-start; margin-bottom: 10px; }
.p-f { display: flex; align-items: center; justify-content: space-between; gap: 10px; margin-top: auto; padding-top: 18px; }
.price { font-size: 20px; color: var(--on); }

/* ảnh chụp ứng dụng */
.shots { display: flex; gap: 22px; overflow-x: auto; padding: 32px 4px 20px; scroll-snap-type: x mandatory; scrollbar-width: thin; }
.shots figure { margin: 0; flex: 0 0 auto; width: min(240px, 62vw); scroll-snap-align: center; text-align: center; }
.shots img { border-radius: 30px; border: 8px solid #111827; box-shadow: 0 24px 40px -18px rgba(10, 30, 80, .45); aspect-ratio: 390 / 844; object-fit: cover; background: #111827; }
.shots figcaption { margin-top: 12px; font-weight: 600; font-size: 15px; }

/* các bước */
.steps { list-style: none; padding: 0; margin: 32px 0 0; display: grid; gap: 18px; grid-template-columns: repeat(auto-fill, minmax(min(100%, 240px), 1fr)); counter-reset: s; }
.steps li { counter-increment: s; background: var(--surface); border: 1px solid var(--line); border-radius: var(--r); padding: 24px; position: relative; }
.steps li::before { content: counter(s); display: grid; place-items: center; width: 38px; height: 38px; border-radius: 50%; background: var(--grad); color: #fff; font-weight: 700; margin-bottom: 14px; }
.steps p { color: var(--muted); margin: 0; }

/* bài viết dạng thẻ */
.card.post { overflow: hidden; text-decoration: none; color: var(--ink); display: flex; flex-direction: column; transition: transform .15s, box-shadow .15s; }
.card.post:hover { transform: translateY(-3px); box-shadow: 0 18px 36px -16px rgba(10, 30, 80, .3); }
.card.post img, .card.post .ph { aspect-ratio: 16 / 9; object-fit: cover; width: 100%; background: var(--bg2); }
.card.post .ph { display: grid; place-items: center; color: var(--on); }
.card.post h3 { font-size: 18px; margin: 6px 0 8px; }
.card.post p { font-size: 15px; display: -webkit-box; -webkit-line-clamp: 3; -webkit-box-orient: vertical; overflow: hidden; margin-bottom: 12px; }
.tag { font-size: 12.5px; font-weight: 600; color: var(--on); text-transform: uppercase; letter-spacing: .04em; }
.tags { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 20px; }
.tags a { padding: 7px 14px; border-radius: 999px; border: 1px solid var(--line); background: var(--surface); color: var(--ink); text-decoration: none; font-size: 14.5px; }
.tags a.on { background: var(--ink); color: var(--bg); border-color: var(--ink); }
.pg { display: flex; gap: 8px; justify-content: center; margin-top: 36px; }
.pg a { min-width: 42px; height: 42px; display: grid; place-items: center; border-radius: 12px; border: 1px solid var(--line); background: var(--surface); text-decoration: none; color: var(--ink); }
.pg a[aria-current] { background: var(--grad); color: #fff; border-color: transparent; }

/* hỏi đáp */
.faq { background: var(--surface); border: 1px solid var(--line); border-radius: 16px; margin-top: 12px; }
.faq summary { cursor: pointer; padding: 18px 52px 18px 22px; font-weight: 600; list-style: none; position: relative; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; position: absolute; right: 22px; top: 50%; transform: translateY(-50%); font-size: 24px; color: var(--on); font-weight: 400; }
.faq[open] summary::after { content: "−"; }
.faq > div { padding: 0 22px 8px; color: var(--muted); }

/* kêu gọi */
.cta { background: var(--grad); color: #fff; border-radius: 28px; padding: clamp(32px, 5vw, 56px); text-align: center; box-shadow: 0 30px 60px -30px var(--glow); }
.cta p { opacity: .92; font-size: 18px; }
.cta .btn:not(.ghost) { background: #fff; color: var(--brand); }

/* liên hệ */
.contact { display: flex; gap: 28px; align-items: flex-start; justify-content: space-between; flex-wrap: wrap; margin-top: 28px; }
.c-l { display: grid; gap: 12px; flex: 1; min-width: min(100%, 300px); max-width: 520px; }
.cbtn { display: flex; gap: 14px; align-items: center; padding: 14px 18px; border-radius: 16px; background: var(--surface); border: 1px solid var(--line); text-decoration: none; color: var(--ink); }
.cbtn .ic { color: var(--on); }
.cbtn small { display: block; color: var(--muted); font-size: 13px; }
.cbtn.big b { font-size: 24px; font-variant-numeric: tabular-nums; }
.soc { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 4px; }
.soc a, .ft-l a { display: inline-flex; align-items: center; gap: 8px; padding: 8px 14px; border-radius: 999px; border: 1px solid var(--line); background: var(--surface); color: var(--ink); text-decoration: none; font-size: 15px; }
.soc .ic, .ft-l .ic { width: 20px; height: 20px; color: var(--on); }
.qr { margin: 0; text-align: center; }
.qr img { background: #fff; border-radius: 18px; padding: 10px; border: 1px solid var(--line); width: 180px; height: 180px; }
.qr figcaption { color: var(--muted); font-size: 14px; margin-top: 8px; }

/* bài viết */
.art { padding: 28px 0 56px; }
.crumb { font-size: 14px; color: var(--muted); margin-bottom: 18px; } .crumb a { color: var(--muted); }
.art h1 { font-size: clamp(28px, 4.4vw, 42px); }
.meta { color: var(--muted); font-size: 15px; }
.cover { border-radius: var(--r); margin: 22px 0 8px; width: 100%; max-height: 520px; object-fit: cover; background: var(--bg2); }
.body { font-size: 18px; }
.body h2 { font-size: 27px; margin-top: 1.6em; } .body h3 { font-size: 21px; margin-top: 1.4em; }
.body img { border-radius: 16px; margin: 18px auto; max-height: 640px; width: auto; }
.body ul, .body ol { padding-left: 1.3em; } .body li { margin: .35em 0; }
.body li.ck { list-style: none; margin-left: -1.3em; } .body li.ck::before { content: "☐ "; } .body li.ck.on::before { content: "☑ "; }
.body blockquote { margin: 1.2em 0; padding: 4px 20px; border-left: 4px solid var(--on); color: var(--muted); }
.body code { font-size: .88em; background: var(--bg2); padding: 2px 6px; border-radius: 6px; }
.body pre { background: #0b1222; color: #e6edf7; padding: 16px 18px; border-radius: 14px; overflow-x: auto; font-size: 14.5px; line-height: 1.55; }
.body pre code { background: none; padding: 0; color: inherit; }
.body hr { border: 0; border-top: 1px solid var(--line); margin: 2em 0; }
.body .btn { margin: 8px 0; }
.tbl { overflow-x: auto; margin: 1.2em 0; }
.body table { border-collapse: collapse; width: 100%; font-size: 16px; }
.body th, .body td { border: 1px solid var(--line); padding: 10px 12px; text-align: left; }
.body th { background: var(--bg2); }
.box { border-radius: 16px; padding: 16px 20px 2px; margin: 1.2em 0; border: 1px solid; }
.box.note { background: var(--on-soft); border-color: color-mix(in srgb, var(--on) 30%, transparent); }
.box.tip { background: color-mix(in srgb, #12c46b 12%, var(--surface)); border-color: color-mix(in srgb, #12c46b 40%, transparent); }
.box.warn { background: color-mix(in srgb, #ff9500 13%, var(--surface)); border-color: color-mix(in srgb, #ff9500 45%, transparent); }
.video { position: relative; aspect-ratio: 16 / 9; margin: 1.2em 0; } .video iframe { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; border-radius: 16px; }
.share { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; margin-top: 36px; padding-top: 22px; border-top: 1px solid var(--line); color: var(--muted); }
.share a { display: inline-flex; align-items: center; gap: 6px; padding: 7px 14px; border-radius: 999px; border: 1px solid var(--line); text-decoration: none; color: var(--ink); background: var(--surface); font-size: 15px; }
.share .ic { width: 18px; height: 18px; color: var(--on); }

/* chân trang */
.ft { background: var(--surface); border-top: 1px solid var(--line); padding: 44px 0 20px; }
.ft .w { display: flex; gap: 30px; justify-content: space-between; flex-wrap: wrap; }
.ft-b { max-width: 420px; } .ft-b img { width: 190px; margin-bottom: 12px; } .ft-b p { color: var(--muted); font-size: 15px; margin: 0 0 6px; }
.ft-l { display: flex; flex-wrap: wrap; gap: 8px; align-content: flex-start; max-width: 560px; }
.ft-c { margin-top: 28px; padding-top: 18px; border-top: 1px solid var(--line); font-size: 14px; color: var(--muted); }
.ft-c a { color: var(--muted); }
@media (prefers-reduced-motion: reduce) { * { transition: none !important; scroll-behavior: auto !important; } }