:root{--bg:#fafbfd;--bg2:#f1f4fa;--card:#fff;--tx:#141b2d;--mu:#5b667d;--bd:#e3e8f2;--pri:#e5322d;--pri2:#c42621;--ok:#12b76a;--ink:#10172a;--r:16px;--sh:0 10px 30px rgba(16,23,42,.08)}
@media (prefers-color-scheme:dark){:root{--bg:#0e131c;--bg2:#141b27;--card:#182131;--tx:#eef1f8;--mu:#a3adc2;--bd:#27324a;--ink:#070b12;--sh:0 10px 30px rgba(0,0,0,.35)}}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--tx);font:16px/1.65 system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;-webkit-font-smoothing:antialiased}
a{color:inherit;text-decoration:none}
h1,h2,h3{line-height:1.2;margin:0;letter-spacing:-.02em}
p{margin:0}
.wrap{width:100%;max-width:1120px;margin:0 auto;padding:0 20px}
.narrow{max-width:800px}
.center{text-align:center}
:focus-visible{outline:3px solid var(--pri);outline-offset:3px;border-radius:6px}

/* nút */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;border-radius:12px;font-weight:700;border:2px solid transparent;cursor:pointer;transition:transform .12s,background .12s,box-shadow .12s}
.btn:hover{transform:translateY(-1px)}
.btn-lg{padding:15px 26px;font-size:1.05rem}
.btn-sm{padding:9px 16px;font-size:.92rem}
.btn-primary{background:var(--pri);color:#fff;box-shadow:0 8px 20px rgba(229,50,45,.32)}
.btn-primary:hover{background:var(--pri2)}
.btn-ghost{background:transparent;color:var(--tx);border-color:var(--bd)}
.btn-ghost:hover{border-color:var(--mu)}
.btn-light{background:#fff;color:var(--pri2)}
.btn-outline-light{background:transparent;color:#fff;border-color:rgba(255,255,255,.55)}
.btn-outline-light:hover{border-color:#fff}

/* thanh đầu trang */
.nav{position:sticky;top:0;z-index:20;background:color-mix(in srgb,var(--bg) 88%,transparent);backdrop-filter:blur(10px);border-bottom:1px solid var(--bd)}
.nav-in{display:flex;align-items:center;gap:24px;height:68px}
.brand{display:inline-flex;align-items:center;gap:8px;font-weight:800;font-size:1.25rem;letter-spacing:-.02em}
.brand-mark{display:inline-grid;place-items:center;width:30px;height:30px;border-radius:9px;background:var(--pri);color:#fff;font-size:.8rem}
.brand.small{font-size:1.05rem}
.nav-links{display:flex;gap:22px;margin-left:12px;flex:1}
.nav-links a{color:var(--mu);font-weight:600;font-size:.95rem}
.nav-links a:hover{color:var(--tx)}
.nav-cta{display:flex;align-items:center;gap:14px}
.link{font-weight:600;color:var(--mu)}
.link:hover{color:var(--tx)}

/* hero */
.hero{background:radial-gradient(1000px 420px at 85% -10%,rgba(229,50,45,.13),transparent 60%),radial-gradient(700px 360px at 0% 0%,rgba(229,50,45,.07),transparent 60%)}
.hero-in{display:grid;grid-template-columns:1.1fr .9fr;gap:48px;align-items:center;padding-top:72px;padding-bottom:72px}
.eyebrow{display:inline-block;padding:6px 14px;border-radius:99px;background:rgba(229,50,45,.1);color:var(--pri2);font-weight:700;font-size:.86rem;margin-bottom:18px}
@media (prefers-color-scheme:dark){.eyebrow{color:#ff8b86}}
.hero h1{font-size:clamp(2.1rem,4.6vw,3.35rem);font-weight:800}
.hl{color:var(--pri)}
.lead{font-size:1.15rem;color:var(--mu);margin-top:20px;max-width:34em}
.lead b{color:var(--tx)}
.cta-row{display:flex;flex-wrap:wrap;gap:14px;margin-top:30px}
.cta-row.center{justify-content:center}
.ticks{list-style:none;padding:0;margin:26px 0 0;display:flex;flex-wrap:wrap;gap:8px 22px;color:var(--mu);font-size:.93rem}
.ticks li::before{content:"✓";color:var(--ok);font-weight:800;margin-right:7px}

/* minh hoạ bảng điều khiển */
.hero-art{display:flex;justify-content:center}
.mock{width:100%;max-width:440px;background:var(--card);border:1px solid var(--bd);border-radius:20px;box-shadow:var(--sh);padding:18px;transform:rotate(1.2deg)}
.mock-top{display:flex;align-items:center;gap:6px;margin-bottom:16px}
.dot{width:10px;height:10px;border-radius:50%;background:var(--bd)}
.mock-tag{margin-left:auto;font-size:.74rem;color:var(--mu)}
.mock-stats{display:grid;grid-template-columns:1.3fr 1fr;gap:12px}
.mock-stat{border:1px solid var(--bd);border-radius:14px;padding:14px;background:var(--bg)}
.mock-stat b{display:block;font-size:2rem;line-height:1.1;font-weight:800}
.mock-stat small{color:var(--mu);font-size:.8rem}
.mock-stat.main b{color:var(--pri)}
.mock-run{margin:14px 0;padding:12px 14px;border-radius:12px;background:rgba(18,183,106,.12);color:#067647;font-weight:700;font-size:.9rem}
@media (prefers-color-scheme:dark){.mock-run{color:#5ee0a4}}
.play{display:inline-grid;place-items:center;width:20px;height:20px;border-radius:50%;background:var(--ok);color:#fff;font-size:.6rem;margin-right:6px}
.mock-row{display:flex;align-items:center;gap:12px;padding:12px 0;border-top:1px solid var(--bd)}
.mock-row:first-child{border-top:0}
.mock-row b{display:block;font-size:.95rem}
.mock-row small{color:var(--mu);font-size:.8rem}
.av{width:38px;height:38px;border-radius:10px;background:var(--pri);color:#fff;display:grid;place-items:center;font-weight:800;flex:none}
.av.alt{background:#4f6bed}
.pill{margin-left:auto;padding:4px 11px;border-radius:99px;background:var(--bg2);font-size:.76rem;font-weight:700;color:var(--mu);white-space:nowrap}
.pill.ok{background:rgba(18,183,106,.15);color:#067647}
@media (prefers-color-scheme:dark){.pill.ok{color:#5ee0a4}}

/* dải số liệu quy tắc */
.facts{border-top:1px solid var(--bd);border-bottom:1px solid var(--bd);background:var(--card)}
.facts-in{display:grid;grid-template-columns:repeat(4,1fr);gap:0}
.fact{padding:26px 20px;border-left:1px solid var(--bd);text-align:center}
.fact:first-child{border-left:0}
.fact b{display:block;font-size:1.25rem;font-weight:800}
.fact span{color:var(--mu);font-size:.88rem}

/* mục */
.sec{padding:84px 0}
.sec-alt{background:var(--bg2)}
.sec h2{font-size:clamp(1.7rem,3.2vw,2.4rem);font-weight:800;text-align:center}
.sec-sub{color:var(--mu);text-align:center;margin:12px auto 44px;max-width:38em;font-size:1.05rem}
.sec-sub.left{text-align:left;margin:16px 0 26px}

/* 3 bước */
.steps{list-style:none;margin:0 0 44px;padding:0;display:grid;grid-template-columns:repeat(3,1fr);gap:22px;counter-reset:s}
.steps li{position:relative;background:var(--card);border:1px solid var(--bd);border-radius:var(--r);padding:30px 26px}
.num{display:inline-grid;place-items:center;width:42px;height:42px;border-radius:50%;background:var(--pri);color:#fff;font-weight:800;margin-bottom:16px}
.steps h3{font-size:1.2rem;margin-bottom:8px}
.steps p{color:var(--mu)}
.steps p b{color:var(--tx)}

/* lợi ích */
.grid{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}
.card{background:var(--card);border:1px solid var(--bd);border-radius:var(--r);padding:28px 26px;transition:transform .15s,box-shadow .15s}
.card:hover{transform:translateY(-3px);box-shadow:var(--sh)}
.ico{width:46px;height:46px;border-radius:13px;background:rgba(229,50,45,.1);display:grid;place-items:center;margin-bottom:16px}
.ico svg{width:24px;height:24px;fill:var(--pri)}
.card h3{font-size:1.15rem;margin-bottom:8px}
.card p{color:var(--mu)}

/* xem tự nhiên */
.split{display:grid;grid-template-columns:1.15fr .85fr;gap:56px;align-items:center}
.split h2{text-align:left}
.check{list-style:none;padding:0;margin:0;display:grid;gap:14px}
.check li{padding-left:34px;position:relative;color:var(--mu)}
.check li b{color:var(--tx)}
.check li::before{content:"✓";position:absolute;left:0;top:1px;width:24px;height:24px;border-radius:50%;background:rgba(18,183,106,.15);color:var(--ok);display:grid;place-items:center;font-weight:800;font-size:.82rem}
.flow{background:var(--card);border:1px solid var(--bd);border-radius:20px;padding:12px 24px;box-shadow:var(--sh)}
.flow-step{display:flex;gap:16px;align-items:flex-start;padding:18px 0;position:relative}
.flow-step+.flow-step{border-top:1px dashed var(--bd)}
.flow-step>span{flex:none;width:34px;height:34px;border-radius:50%;background:var(--ink);color:#fff;display:grid;place-items:center;font-weight:800;font-size:.9rem}
@media (prefers-color-scheme:dark){.flow-step>span{background:var(--pri)}}
.flow-step b{display:block}
.flow-step small{color:var(--mu);font-size:.88rem}

/* dành cho ai */
.who{display:grid;grid-template-columns:repeat(3,1fr);gap:22px;margin-top:36px}
.who>div{padding:26px;border-left:4px solid var(--pri);background:var(--card);border-radius:0 var(--r) var(--r) 0}
.who h3{font-size:1.1rem;margin-bottom:6px}
.who p{color:var(--mu)}

/* hỏi đáp */
.faq{margin-top:36px;display:grid;gap:12px}
details{background:var(--card);border:1px solid var(--bd);border-radius:14px;padding:0 22px}
summary{cursor:pointer;list-style:none;padding:18px 0;font-weight:700;display:flex;justify-content:space-between;gap:16px;align-items:center}
summary::-webkit-details-marker{display:none}
summary::after{content:"+";font-size:1.4rem;color:var(--pri);line-height:1;flex:none}
details[open] summary::after{content:"–"}
details p{padding:0 0 20px;color:var(--mu)}
details p b{color:var(--tx)}

/* CTA cuối */
.final{background:linear-gradient(135deg,#e5322d,#b81f1a);color:#fff;padding:76px 0;text-align:center}
.final h2{font-size:clamp(1.7rem,3.4vw,2.5rem);font-weight:800;max-width:20em;margin:0 auto}
.final p{opacity:.92;margin-top:14px;font-size:1.1rem}

/* chân trang */
.foot{padding:30px 0;border-top:1px solid var(--bd)}
.foot-in{display:flex;flex-wrap:wrap;gap:12px 24px;align-items:center;justify-content:space-between}
.foot p{color:var(--mu);font-size:.85rem}

/* thiết bị nhỏ */
@media (max-width:900px){
  .nav-links{display:none}
  .nav-in{justify-content:space-between}
  .hero-in{grid-template-columns:1fr;padding-top:44px;padding-bottom:48px;gap:34px}
  .mock{transform:none}
  .facts-in{grid-template-columns:repeat(2,1fr)}
  .fact:nth-child(3){border-left:0}
  .fact:nth-child(n+3){border-top:1px solid var(--bd)}
  .steps,.grid,.who{grid-template-columns:1fr}
  .split{grid-template-columns:1fr;gap:34px}
  .sec{padding:56px 0}
}
@media (max-width:480px){
  .link{display:none}
  .btn-lg{width:100%}
  .cta-row .btn{width:100%}
}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}*{transition:none!important}}