:root {
  --bg: #fbf7f3;
  --surface: #ffffff;
  --ink: #211a26;
  --ink-soft: #5d5566;
  --line: #ece4dc;
  --plum: #3a1f3d;
  --plum-2: #5a2f5e;
  --gold: #c79a55;
  --gold-2: #b07f3a;
  --rose: #d98a8a;
  --ok: #2f8f6b;
  --radius: 18px;
  --shadow: 0 10px 40px rgba(58, 31, 61, 0.10);
  --maxw: 1080px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: "Be Vietnam Pro", system-ui, -apple-system, sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
h1, h2, h3 { line-height: 1.2; letter-spacing: -0.01em; margin: 0 0 .5em; }
h1 { font-size: clamp(2rem, 5vw, 3.4rem); font-weight: 800; }
h2 { font-size: clamp(1.5rem, 3.5vw, 2.3rem); font-weight: 700; }
p { margin: 0 0 1em; }
a { color: inherit; }
.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 22px; }
.muted { color: var(--ink-soft); }
.center { text-align: center; }

/* Buttons */
.btn {
  display: inline-flex; align-items: center; gap: .5em;
  padding: .85em 1.5em; border-radius: 999px;
  font-weight: 600; font-size: 1rem; text-decoration: none;
  border: 1px solid transparent; cursor: pointer; transition: transform .12s ease, box-shadow .12s ease;
}
.btn:hover { transform: translateY(-2px); }
.btn-primary { background: linear-gradient(135deg, var(--gold), var(--gold-2)); color: #fff; box-shadow: 0 8px 24px rgba(199,154,85,.35); }
.btn-ghost { background: transparent; color: var(--plum); border-color: var(--line); }
.btn-ghost:hover { border-color: var(--gold); }
.btn-lg { padding: 1.05em 2em; font-size: 1.08rem; }

/* Header */
header.nav {
  position: sticky; top: 0; z-index: 50;
  background: rgba(251,247,243,.82); backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 66px; }
.brand { font-weight: 800; font-size: 1.15rem; letter-spacing: -.02em; text-decoration: none; color: var(--plum); }
.brand span { color: var(--gold-2); }
.nav-links { display: flex; gap: 26px; align-items: center; }
.nav-links a { text-decoration: none; color: var(--ink-soft); font-size: .95rem; font-weight: 500; }
.nav-links a:hover { color: var(--plum); }
.nav-cta { display: inline-flex; }
@media (max-width: 800px) { .nav-links a:not(.nav-cta) { display: none; } }

/* Hero */
.hero { padding: 72px 0 56px; position: relative; overflow: hidden; }
.hero::after {
  content: ""; position: absolute; top: -120px; right: -120px; width: 420px; height: 420px;
  background: radial-gradient(circle, rgba(217,138,138,.18), transparent 70%); z-index: 0;
}
.hero .wrap { position: relative; z-index: 1; }
.pill {
  display: inline-flex; align-items: center; gap: .5em;
  background: #fff; border: 1px solid var(--line); color: var(--plum);
  padding: .4em 1em; border-radius: 999px; font-size: .85rem; font-weight: 600; margin-bottom: 22px;
}
.dot { width: 8px; height: 8px; border-radius: 50%; background: var(--ok); box-shadow: 0 0 0 4px rgba(47,143,107,.18); }
.hero h1 { max-width: 16ch; }
.hero-sub { font-size: 1.2rem; color: var(--ink-soft); max-width: 52ch; margin-bottom: 28px; }
.hero-cta { display: flex; gap: 14px; flex-wrap: wrap; margin-bottom: 18px; }
.hero-note { font-size: .9rem; color: var(--ink-soft); }

/* Sections */
section { padding: 64px 0; }
.eyebrow { text-transform: uppercase; letter-spacing: .14em; font-size: .8rem; font-weight: 700; color: var(--gold-2); margin-bottom: 10px; }
.section-head { max-width: 60ch; margin-bottom: 40px; }
.alt { background: var(--surface); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }

/* Cards grid */
.grid { display: grid; gap: 20px; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
@media (max-width: 860px) { .grid-3, .grid-4 { grid-template-columns: 1fr 1fr; } }
@media (max-width: 560px) { .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; } }
.card {
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 26px; box-shadow: var(--shadow);
}
.alt .card { background: var(--bg); }
.card .ico { font-size: 1.7rem; margin-bottom: 12px; display: block; }
.card h3 { font-size: 1.12rem; }
.card p { font-size: .96rem; color: var(--ink-soft); margin: 0; }

/* Steps */
.steps { counter-reset: step; }
.step { display: flex; gap: 20px; align-items: flex-start; padding: 22px 0; border-bottom: 1px dashed var(--line); }
.step:last-child { border-bottom: none; }
.step .num {
  counter-increment: step; flex: 0 0 auto;
  width: 46px; height: 46px; border-radius: 50%;
  background: linear-gradient(135deg, var(--plum), var(--plum-2)); color: #fff;
  display: grid; place-items: center; font-weight: 700; font-size: 1.1rem;
}
.step .num::before { content: counter(step); }
.step h3 { margin-bottom: 4px; }
.step p { margin: 0; color: var(--ink-soft); }

/* Stats */
.stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
@media (max-width: 700px) { .stats { grid-template-columns: 1fr 1fr; } }
.stat { text-align: center; padding: 22px 12px; }
.stat .n { font-size: clamp(1.8rem, 4vw, 2.6rem); font-weight: 800; color: var(--plum); letter-spacing: -.02em; }
.stat .l { font-size: .9rem; color: var(--ink-soft); }

/* Pricing */
.price-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; align-items: stretch; }
@media (max-width: 860px) { .price-grid { grid-template-columns: 1fr; max-width: 460px; margin: 0 auto; } }
.plan { display: flex; flex-direction: column; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 28px; box-shadow: var(--shadow); }
.plan.feat { border: 2px solid var(--gold); position: relative; }
.plan.feat::before { content: "Phổ biến"; position: absolute; top: -13px; left: 50%; transform: translateX(-50%); background: var(--gold); color: #fff; font-size: .75rem; font-weight: 700; padding: .25em 1em; border-radius: 999px; }
.plan h3 { font-size: 1.3rem; color: var(--plum); }
.plan .price { font-size: 1.05rem; font-weight: 600; color: var(--ink); margin: 6px 0 16px; }
.plan .price b { font-size: 1.5rem; }
.plan ul { list-style: none; padding: 0; margin: 0 0 22px; flex: 1; }
.plan li { padding: 8px 0; padding-left: 26px; position: relative; font-size: .95rem; color: var(--ink-soft); border-top: 1px solid var(--line); }
.plan li:first-child { border-top: none; }
.plan li::before { content: "✓"; position: absolute; left: 0; color: var(--ok); font-weight: 700; }
.plan .btn { width: 100%; justify-content: center; }

/* CTA band */
.cta-band { background: linear-gradient(135deg, var(--plum), var(--plum-2)); color: #fff; border-radius: 24px; padding: 54px 40px; text-align: center; }
.cta-band h2 { color: #fff; }
.cta-band p { color: rgba(255,255,255,.82); max-width: 50ch; margin: 0 auto 26px; }

/* FAQ / objections */
.faq details { background: var(--surface); border: 1px solid var(--line); border-radius: 14px; padding: 4px 20px; margin-bottom: 12px; }
.faq summary { cursor: pointer; font-weight: 600; padding: 16px 0; list-style: none; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; float: right; color: var(--gold-2); font-weight: 700; }
.faq details[open] summary::after { content: "–"; }
.faq details p { color: var(--ink-soft); padding-bottom: 16px; margin: 0; }

/* Footer */
footer { background: var(--plum); color: rgba(255,255,255,.75); padding: 48px 0 32px; margin-top: 40px; }
footer a { color: #fff; text-decoration: none; }
footer .cols { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 24px; margin-bottom: 28px; }
footer .brand { color: #fff; }
footer small { color: rgba(255,255,255,.55); }

/* Case study extras */
.lead { font-size: 1.18rem; color: var(--ink-soft); max-width: 60ch; }
.quote { border-left: 4px solid var(--gold); padding: 8px 0 8px 22px; font-size: 1.15rem; color: var(--plum); font-style: italic; margin: 28px 0; }
.tag { display: inline-block; background: #fff; border: 1px solid var(--line); border-radius: 999px; padding: .3em 1em; font-size: .85rem; margin: 0 6px 8px 0; color: var(--ink-soft); }