/* Design tokens — B2B Service: Trust & Authority + Minimal (ui-ux-pro-max) */
:root {
  --primary: #0F172A;      /* navy */
  --on-primary: #fff;
  --secondary: #334155;
  --accent: #0369A1;       /* trust blue */
  --cta: #EA580C;          /* cam: chỉ dùng cho CTA */
  --cta-hover: #C2410C;
  --bg: #F8FAFC;
  --fg: #020617;
  --card: #fff;
  --muted: #E8ECF1;
  --muted-fg: #475569;
  --border: #E2E8F0;
  --error: #DC2626;
  --radius: 14px;
  --shadow: 0 1px 2px rgb(15 23 42 / .06), 0 4px 16px rgb(15 23 42 / .06);
  --shadow-lg: 0 12px 32px rgb(15 23 42 / .12);
  --ease: cubic-bezier(.2, .8, .2, 1);
  --z-nav: 40;
  --z-float: 100;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 80px; -webkit-text-size-adjust: 100%; }
body { margin: 0; font: 400 16px/1.6 "Be Vietnam Pro", system-ui, sans-serif; color: var(--fg); background: var(--bg); }
h1, h2, h3 { line-height: 1.2; margin: 0 0 .5em; color: var(--primary); }
h1 { font-size: clamp(2rem, 4.2vw, 3.1rem); text-wrap: balance; font-weight: 700; letter-spacing: -.02em; }
h2 { text-wrap: balance; font-size: clamp(1.6rem, 3.2vw, 2.3rem); font-weight: 700; letter-spacing: -.01em; }
h3 { font-size: 1.125rem; font-weight: 600; }
p { margin: 0 0 1em; }
a { color: var(--accent); }
img { max-width: 100%; height: auto; }
:focus-visible { outline: 3px solid var(--accent); outline-offset: 2px; border-radius: 6px; }

.wrap { width: min(1160px, 100% - 40px); margin-inline: auto; }
.skip { position: absolute; left: -999px; top: 8px; background: var(--primary); color: #fff; padding: 8px 14px; border-radius: 8px; z-index: 1000; }
.skip:focus { left: 8px; }
.ic { width: 20px; height: 20px; flex: none; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }
.ic--lg { width: 28px; height: 28px; }

/* Buttons */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; min-height: 48px; padding: 0 22px; border-radius: 10px; border: 2px solid transparent; font: 600 1rem/1 inherit; text-decoration: none; cursor: pointer; touch-action: manipulation; transition: background-color .2s var(--ease), color .2s var(--ease), transform .15s var(--ease), border-color .2s var(--ease); }
.btn:active { transform: scale(.97); }
.btn--cta { background: var(--cta); color: #fff; }
.btn--cta:hover { background: var(--cta-hover); }
.btn--ghost { border-color: var(--border); color: var(--primary); background: var(--card); }
.btn--ghost:hover { border-color: var(--primary); }
.btn--sm { min-height: 44px; padding: 0 16px; }
.btn[disabled] { opacity: .6; cursor: progress; }

/* Nav */
.nav { position: sticky; top: 0; z-index: var(--z-nav); background: rgb(248 250 252 / .9); backdrop-filter: saturate(1.5) blur(10px); border-bottom: 1px solid var(--border); }
.nav__in { display: flex; align-items: center; justify-content: space-between; min-height: 68px; }
.brand { display: inline-flex; align-items: center; gap: 10px; font-weight: 600; font-size: 1.1rem; color: var(--primary); text-decoration: none; margin: 0; }
.brand b { color: var(--cta); font-weight: 700; }
.brand__mark { display: grid; place-items: center; width: 38px; height: 38px; border-radius: 10px; background: var(--primary); color: #fff; font-weight: 700; font-size: .9rem; letter-spacing: .02em; }
.nav__menu { display: flex; align-items: center; gap: 28px; }
.nav__menu a:not(.btn) { color: var(--secondary); text-decoration: none; font-weight: 500; padding: 10px 0; }
.nav__menu a:not(.btn):hover { color: var(--primary); }
.nav__toggle { display: none; width: 44px; height: 44px; border: 1px solid var(--border); border-radius: 10px; background: var(--card); color: var(--primary); cursor: pointer; }
.nav__toggle .ic { width: 22px; height: 22px; }

/* Hero */
.hero { padding: clamp(48px, 8vw, 96px) 0; background: radial-gradient(900px 400px at 85% 10%, rgb(3 105 161 / .08), transparent 70%); }
.hero__in { display: grid; grid-template-columns: 1.1fr .9fr; gap: 56px; align-items: center; }
.eyebrow { font-size: .85rem; font-weight: 600; letter-spacing: .08em; text-transform: uppercase; color: var(--accent); margin-bottom: .75em; }
.eyebrow--light { color: #7DD3FC; }
.hl { color: var(--accent); }
.lead { font-size: 1.125rem; color: var(--muted-fg); max-width: 60ch; }
.hero__cta { display: flex; flex-wrap: wrap; gap: 12px; margin: 28px 0; }
.proof { list-style: none; padding: 0; margin: 0; display: flex; flex-wrap: wrap; gap: 10px 24px; color: var(--secondary); font-weight: 500; }
.proof li { display: inline-flex; align-items: center; gap: 8px; }
.proof .ic { color: #16A34A; }

.mock { background: var(--card); border: 1px solid var(--border); border-radius: 18px; box-shadow: var(--shadow-lg); padding: 18px; }
.mock__bar { display: flex; gap: 6px; margin-bottom: 14px; }
.mock__bar i { width: 10px; height: 10px; border-radius: 50%; background: var(--muted); }
.mock__row { display: flex; align-items: center; gap: 12px; padding: 12px; border-radius: 10px; background: var(--bg); margin-bottom: 8px; font-size: .95rem; color: var(--secondary); }
.mock__row span { flex: 1; }
.mock__row .ic { color: var(--accent); }
.mock__row em { font-style: normal; font-size: .8rem; font-weight: 600; color: var(--muted-fg); background: var(--muted); padding: 3px 8px; border-radius: 99px; }
.mock__row em.up { color: #15803D; background: #DCFCE7; }
.mock__bars { display: flex; align-items: flex-end; gap: 10px; height: 110px; padding: 12px 4px 0; }
.mock__bars span { flex: 1; height: var(--h); border-radius: 6px 6px 0 0; background: linear-gradient(to top, var(--accent), #38BDF8); }

/* Sections */
.sec { padding: clamp(56px, 8vw, 96px) 0; }
.sec--alt { background: #fff; border-block: 1px solid var(--border); }
.sec--dark { background: var(--primary); color: #CBD5E1; }
.sec--dark h2, .sec--dark h3 { color: #fff; }
.sec__head { max-width: 720px; margin-bottom: 40px; }

.grid { display: grid; gap: 20px; }
.grid--3 { grid-template-columns: repeat(3, 1fr); }
.grid--4 { grid-template-columns: repeat(4, 1fr); }

.card { position: relative; background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 28px; box-shadow: var(--shadow); transition: transform .2s var(--ease), box-shadow .2s var(--ease), border-color .2s var(--ease); }
.card:hover { transform: translateY(-3px); box-shadow: var(--shadow-lg); border-color: #CBD5E1; }
.card .ic--lg { color: var(--accent); margin-bottom: 16px; }
.card p { color: var(--muted-fg); margin: 0; }
.card--feat { border-color: var(--primary); }
.badge { position: absolute; top: 20px; right: 20px; font-size: .75rem; font-weight: 600; color: var(--cta); background: #FFEDD5; padding: 4px 10px; border-radius: 99px; }

.chips { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; }
.chips li { display: flex; align-items: center; gap: 12px; padding: 18px 20px; border: 1px solid var(--border); border-radius: 12px; background: var(--bg); font-weight: 500; color: var(--primary); }
.chips .ic { color: var(--accent); }

.steps { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; counter-reset: s; }
.steps li { padding: 24px; border-top: 3px solid var(--primary); background: var(--card); border-radius: 0 0 var(--radius) var(--radius); box-shadow: var(--shadow); }
.steps b { display: block; font-size: 1.5rem; color: var(--cta); margin-bottom: 8px; font-variant-numeric: tabular-nums; }
.steps p { color: var(--muted-fg); margin: 0; }

.why { padding: 24px; border: 1px solid rgb(255 255 255 / .1); border-radius: var(--radius); background: rgb(255 255 255 / .03); }
.why .ic--lg { color: #7DD3FC; margin-bottom: 14px; }
.why p { margin: 0; }

.case { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow); }
.case__img { aspect-ratio: 16 / 10; display: grid; place-items: center; background: repeating-linear-gradient(45deg, var(--muted) 0 12px, var(--bg) 12px 24px); color: var(--muted-fg); font-weight: 500; }
.case h3, .case p { padding-inline: 22px; }
.case h3 { margin-top: 18px; }
.case p { color: var(--muted-fg); }

/* Contact */
.contact { display: grid; grid-template-columns: .9fr 1.1fr; gap: 56px; align-items: start; }
.contact__list { list-style: none; padding: 0; margin: 24px 0 0; display: grid; gap: 14px; }
.contact__list li { display: flex; align-items: center; gap: 12px; color: var(--secondary); }
.contact__list .ic { color: var(--accent); }
.form { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; background: var(--bg); border: 1px solid var(--border); border-radius: 18px; padding: 28px; }
.field { display: grid; gap: 6px; }
.field--full { grid-column: 1 / -1; }
.field label { font-weight: 500; font-size: .95rem; color: var(--primary); }
.field input, .field select, .field textarea { font: inherit; font-size: 16px; color: var(--fg); background: #fff; border: 1px solid #CBD5E1; border-radius: 10px; padding: 12px 14px; min-height: 48px; transition: border-color .2s var(--ease), box-shadow .2s var(--ease); }
.field input:focus, .field select:focus, .field textarea:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px rgb(3 105 161 / .2); }
.field [aria-invalid="true"] { border-color: var(--error); }
.err { color: var(--error); font-size: .85rem; min-height: 1em; }
.form__msg { margin: 0; color: #15803D; font-weight: 500; }

/* Footer */
.foot { background: var(--primary); color: #94A3B8; padding: 48px 0 24px; }
.foot__in { display: grid; grid-template-columns: 1fr 1fr; gap: 32px; }
.foot a { color: #E2E8F0; }
.brand--light { color: #fff; margin-bottom: 12px; }
.brand--light .brand__mark { background: #fff; color: var(--primary); }
.foot__copy { border-top: 1px solid rgb(255 255 255 / .1); padding-top: 20px; margin-top: 24px; font-size: .9rem; }

/* Floating contact */
.float { position: fixed; right: 16px; bottom: calc(16px + env(safe-area-inset-bottom)); z-index: var(--z-float); display: grid; gap: 12px; }
.float__btn { display: grid; place-items: center; width: 56px; height: 56px; border-radius: 50%; color: #fff; text-decoration: none; font-weight: 700; font-size: .85rem; box-shadow: var(--shadow-lg); transition: transform .2s var(--ease); }
.float__btn:hover { transform: scale(1.06); }
.float__btn--zalo { background: #0068FF; }
.float__btn--call { background: var(--cta); }
.float__btn .ic { width: 24px; height: 24px; }

/* Scroll reveal (chỉ khi JS chạy và người dùng không tắt chuyển động) */
.js .reveal { opacity: 0; transform: translateY(16px); transition: opacity .5s var(--ease), transform .5s var(--ease); }
.js .reveal.in { opacity: 1; transform: none; }

/* Responsive: 1024 / 768 */
@media (max-width: 1024px) {
  .grid--4, .steps { grid-template-columns: repeat(2, 1fr); }
  .hero__in, .contact { grid-template-columns: 1fr; gap: 40px; }
}
@media (max-width: 768px) {
  .nav__toggle { display: grid; place-items: center; }
  .nav__menu { position: absolute; inset: 68px 0 auto; flex-direction: column; align-items: stretch; gap: 0; padding: 8px 20px 20px; background: var(--bg); border-bottom: 1px solid var(--border); box-shadow: var(--shadow); display: none; }
  .nav__menu.open { display: flex; }
  .nav__menu a:not(.btn) { padding: 14px 0; border-bottom: 1px solid var(--border); }
  .nav__menu .btn { margin-top: 14px; }
  .grid--3, .chips, .foot__in { grid-template-columns: 1fr; }
  .form { grid-template-columns: 1fr; padding: 20px; }
  .hero__card { display: none; }
}
@media (max-width: 480px) {
  .grid--4, .steps { grid-template-columns: 1fr; }
  .hero__cta .btn { flex: 1 1 100%; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; animation: none !important; }
  .js .reveal { opacity: 1; transform: none; }
}