/* long4 — trang giới thiệu (marketing) */
:root{
  --bg:#0a0a0a; --bg2:#111214; --card:#161719; --line:#26272b;
  --fg:#fafafa; --muted:#a1a1aa; --muted2:#71717a;
  --brand:#059669; --brand2:#34d399; --brandsoft:#052e23;
  --radius:16px; --max:1080px;
  --font:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,"Noto Sans","Liberation Sans",sans-serif;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--fg);font-family:var(--font);line-height:1.6;-webkit-font-smoothing:antialiased}
a{color:inherit;text-decoration:none}
img{max-width:100%;display:block}
.wrap{max-width:var(--max);margin:0 auto;padding:0 20px}
.muted{color:var(--muted)}

/* nav */
header.nav{position:sticky;top:0;z-index:30;background:rgba(10,10,10,.72);backdrop-filter:saturate(150%) blur(12px);border-bottom:1px solid var(--line)}
.nav .wrap{display:flex;align-items:center;justify-content:space-between;height:64px;gap:16px}
.brand{display:flex;align-items:center;gap:10px;font-weight:800;font-size:18px}
.brand .dot{width:28px;height:28px;border-radius:8px;background:linear-gradient(135deg,var(--brand),var(--brand2));display:grid;place-items:center;color:#04140e;font-weight:900}
.nav nav{display:flex;gap:22px;align-items:center}
.nav nav a{color:var(--muted);font-size:14.5px;font-weight:500}
.nav nav a:hover{color:var(--fg)}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:11px 18px;border-radius:12px;font-weight:700;font-size:14.5px;border:1px solid transparent;cursor:pointer;transition:.15s}
.btn-primary{background:var(--brand);color:#fff}
.btn-primary:hover{background:#047857}
.btn-ghost{background:transparent;border-color:var(--line);color:var(--fg)}
.btn-ghost:hover{border-color:#3f3f46}
.nav-cta{display:flex;gap:10px}
@media(max-width:760px){.nav nav.links{display:none}}

/* hero */
.hero{position:relative;padding:84px 0 64px;text-align:center;overflow:hidden}
.hero::before{content:"";position:absolute;inset:0;background:radial-gradient(60% 60% at 50% 0%,rgba(5,150,105,.18),transparent 70%);pointer-events:none}
.pill{display:inline-flex;align-items:center;gap:8px;padding:6px 14px;border:1px solid var(--line);border-radius:999px;font-size:13px;color:var(--brand2);background:var(--brandsoft);margin-bottom:22px}
.hero h1{font-size:clamp(32px,6vw,56px);line-height:1.08;margin:0 0 18px;font-weight:850;letter-spacing:-.02em}
.hero h1 .g{background:linear-gradient(120deg,var(--brand2),#a7f3d0);-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent}
.hero p.lead{font-size:clamp(16px,2.4vw,20px);color:var(--muted);max-width:640px;margin:0 auto 30px}
.hero .cta{display:flex;gap:12px;justify-content:center;flex-wrap:wrap}
.hero .note{margin-top:16px;font-size:13px;color:var(--muted2)}

/* sections */
section{padding:64px 0}
.eyebrow{color:var(--brand2);font-weight:700;font-size:13px;letter-spacing:.08em;text-transform:uppercase}
h2.sec{font-size:clamp(26px,4vw,38px);font-weight:800;letter-spacing:-.02em;margin:10px 0 12px}
.sub{color:var(--muted);max-width:620px}
.center{text-align:center;margin-left:auto;margin-right:auto}

.grid{display:grid;gap:18px;margin-top:36px}
.g3{grid-template-columns:repeat(3,1fr)}
.g2{grid-template-columns:repeat(2,1fr)}
@media(max-width:860px){.g3{grid-template-columns:1fr 1fr}}
@media(max-width:560px){.g3,.g2{grid-template-columns:1fr}}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:22px}
.card .ico{width:44px;height:44px;border-radius:12px;background:var(--brandsoft);color:var(--brand2);display:grid;place-items:center;margin-bottom:14px}
.card .ico svg{width:23px;height:23px}
.pill svg{width:15px;height:15px;vertical-align:-2px;margin-right:2px}
.store .em svg{width:24px;height:24px;color:var(--brand2)}
.card h3{margin:0 0 6px;font-size:17px}
.card p{margin:0;color:var(--muted);font-size:14.5px}

/* pricing */
.prices{display:grid;grid-template-columns:repeat(3,1fr);gap:18px;margin-top:36px}
@media(max-width:820px){.prices{grid-template-columns:1fr}}
.price{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:26px;display:flex;flex-direction:column}
.price.pop{border-color:var(--brand);box-shadow:0 0 0 1px var(--brand)}
.price .tag{font-weight:700;font-size:15px;color:var(--brand2)}
.price .amt{font-size:34px;font-weight:850;margin:8px 0 2px}
.price .amt small{font-size:15px;font-weight:600;color:var(--muted)}
.price ul{list-style:none;padding:0;margin:18px 0 22px;display:flex;flex-direction:column;gap:10px}
.price li{font-size:14.5px;color:var(--muted);display:flex;gap:10px}
.price li::before{content:"✓";color:var(--brand2);font-weight:900}
.price .btn{margin-top:auto}

/* download */
.dl{display:flex;gap:14px;justify-content:center;flex-wrap:wrap;margin-top:30px}
.store{display:flex;align-items:center;gap:12px;background:var(--card);border:1px solid var(--line);border-radius:14px;padding:12px 20px;min-width:210px}
.store .em{font-size:26px}
.store b{display:block;font-size:15px}
.store span{font-size:12.5px;color:var(--muted)}

/* cta band */
.band{background:linear-gradient(135deg,#04241a,#052e23);border:1px solid var(--line);border-radius:24px;padding:44px;text-align:center;margin:20px 0}
.band h2{font-size:clamp(24px,4vw,34px);margin:0 0 10px}
.band p{color:var(--brand2);margin:0 0 22px}

/* footer */
footer{border-top:1px solid var(--line);padding:44px 0 60px;color:var(--muted)}
footer .cols{display:flex;flex-wrap:wrap;gap:40px;justify-content:space-between}
footer h4{color:var(--fg);font-size:14px;margin:0 0 12px}
footer a{display:block;color:var(--muted);font-size:14px;padding:4px 0}
footer a:hover{color:var(--fg)}
footer .copy{margin-top:34px;padding-top:20px;border-top:1px solid var(--line);font-size:13px;color:var(--muted2);display:flex;justify-content:space-between;flex-wrap:wrap;gap:10px}

/* legal / doc pages */
.doc{max-width:800px;margin:0 auto;padding:52px 20px 80px}
.doc h1{font-size:clamp(28px,5vw,40px);margin:0 0 6px;letter-spacing:-.02em}
.doc .updated{color:var(--muted2);font-size:13.5px;margin-bottom:34px}
.doc h2{font-size:21px;margin:34px 0 10px;padding-top:6px}
.doc h3{font-size:16.5px;margin:22px 0 8px;color:var(--brand2)}
.doc p,.doc li{color:#d4d4d8;font-size:15.5px}
.doc ul{padding-left:22px;display:flex;flex-direction:column;gap:6px}
.doc a{color:var(--brand2);text-decoration:underline}
.doc .toc{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:18px 22px;margin:24px 0}
.doc .toc a{display:block;padding:4px 0;text-decoration:none}
.backlink{display:inline-flex;gap:6px;color:var(--muted);font-size:14px;margin-bottom:22px}