/* DN Mới — NHQN landing style. Neutral editorial, cam #E8825A CTA only, no glow/gradient decorative. */
:root {
  --ink: #1A1A1A;
  --cream: #F5F0E8;
  --cream-deep: #EBE4D6;
  --cam: #E8825A;
  --cam-hover: #D26F47;
  --muted: #5A554C;
  --line: rgba(26, 26, 26, 0.12);
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: 'DM Sans', system-ui, -apple-system, sans-serif;
  font-weight: 400;
  color: var(--ink);
  background: var(--cream);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
.container { max-width: 1100px; margin: 0 auto; padding: 0 24px; }
h1, h2, h3 { font-family: 'Playfair Display', Georgia, serif; font-weight: 400; line-height: 1.2; }
em { font-style: italic; color: var(--cam); }
code { font-family: 'JetBrains Mono', monospace; font-size: 0.92em; background: var(--cream-deep); padding: 0.1em 0.4em; border-radius: 3px; }
a { color: var(--cam); text-decoration: none; }
a:hover { color: var(--cam-hover); text-decoration: underline; }
button, .btn { cursor: pointer; border: none; font-family: inherit; }

/* Topbar */
.topbar { padding: 18px 0; border-bottom: 1px solid var(--line); position: sticky; top: 0; background: var(--cream); z-index: 50; }
.topbar .container { display: flex; align-items: center; justify-content: space-between; }
.brand { color: var(--ink); font-weight: 600; font-size: 17px; }
.brand-mark { color: var(--cam); }
.nav { display: flex; gap: 28px; font-size: 15px; }
.nav a { color: var(--muted); }
.nav .cta-link { color: var(--cam); font-weight: 500; }

/* Hero */
.hero { padding: 96px 0 80px; }
.eyebrow { font-family: 'JetBrains Mono', monospace; font-size: 12px; letter-spacing: 0.12em; text-transform: uppercase; color: var(--muted); margin-bottom: 28px; }
.hero h1 { font-size: clamp(38px, 5.5vw, 64px); margin-bottom: 24px; }
.lede { font-size: 19px; color: var(--muted); max-width: 720px; margin-bottom: 40px; line-height: 1.55; }
.hero-actions { display: flex; gap: 16px; flex-wrap: wrap; margin-bottom: 32px; }
.btn {
  display: inline-flex; align-items: center; padding: 14px 28px; font-size: 15px; font-weight: 500;
  border-radius: 4px; transition: background 0.15s, color 0.15s;
  text-decoration: none;
}
.btn-primary { background: var(--cam); color: white; }
.btn-primary:hover { background: var(--cam-hover); color: white; text-decoration: none; }
.btn-ghost { background: transparent; color: var(--ink); border: 1px solid var(--line); }
.btn-ghost:hover { background: var(--cream-deep); color: var(--ink); text-decoration: none; }
.hero-meta { font-size: 14px; color: var(--muted); display: flex; gap: 12px; flex-wrap: wrap; }

/* How */
.how { padding: 80px 0; border-top: 1px solid var(--line); }
.how h2 { font-size: 36px; margin-bottom: 48px; }
.steps { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 40px; }
.step-num { font-family: 'JetBrains Mono', monospace; color: var(--cam); font-size: 14px; display: block; margin-bottom: 12px; }
.step h3 { font-size: 22px; margin-bottom: 12px; }
.step p { color: var(--muted); }

/* Pricing */
.pricing { padding: 80px 0; background: var(--cream-deep); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.pricing h2 { font-size: 36px; margin-bottom: 12px; }
.pricing .sub { color: var(--muted); margin-bottom: 48px; }
.plans { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 24px; }
.plan { background: var(--cream); padding: 32px 28px; border: 1px solid var(--line); border-radius: 4px; position: relative; display: flex; flex-direction: column; }
.plan h3 { font-size: 22px; margin-bottom: 16px; }
.plan .price { margin-bottom: 24px; }
.plan .amount { font-family: 'Playfair Display', serif; font-size: 36px; font-weight: 400; }
.plan .period { color: var(--muted); font-size: 14px; margin-left: 6px; }
.plan ul { list-style: none; margin-bottom: 28px; flex: 1; }
.plan li { font-size: 14px; color: var(--muted); padding: 8px 0; border-bottom: 1px solid var(--line); }
.plan li:last-child { border-bottom: none; }
.plan .btn { width: 100%; justify-content: center; }
.plan-featured { background: var(--ink); color: var(--cream); border-color: var(--cam); }
.plan-featured h3, .plan-featured .amount { color: var(--cream); }
.plan-featured .period, .plan-featured li { color: rgba(245, 240, 232, 0.7); }
.plan-featured li { border-bottom-color: rgba(245, 240, 232, 0.12); }
.plan-featured .btn-ghost { color: var(--cream); border-color: rgba(245, 240, 232, 0.3); }
.badge { position: absolute; top: -12px; left: 28px; background: var(--cam); color: white; font-size: 11px; padding: 4px 10px; border-radius: 3px; font-family: 'JetBrains Mono', monospace; letter-spacing: 0.05em; }

/* Use cases */
.usecase { padding: 80px 0; }
.usecase h2 { font-size: 36px; margin-bottom: 48px; }
.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 32px; }
.card { padding: 28px; border-left: 2px solid var(--cam); background: transparent; }
.card h3 { font-size: 20px; margin-bottom: 12px; }
.card p { color: var(--muted); font-size: 15px; }

/* FAQ */
.faq { padding: 80px 0; border-top: 1px solid var(--line); }
.faq h2 { font-size: 36px; margin-bottom: 32px; }
.faq details { padding: 24px 0; border-bottom: 1px solid var(--line); cursor: pointer; }
.faq summary { font-weight: 600; font-size: 17px; outline: none; list-style: none; position: relative; padding-right: 30px; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; position: absolute; right: 0; top: 0; color: var(--cam); font-size: 22px; transition: transform 0.2s; }
.faq details[open] summary::after { transform: rotate(45deg); }
.faq details p { margin-top: 12px; color: var(--muted); }

/* Footer */
footer { padding: 48px 0; background: var(--ink); color: rgba(245, 240, 232, 0.7); font-size: 14px; }
footer .container { display: flex; flex-direction: column; gap: 12px; }
footer a { color: rgba(245, 240, 232, 0.85); }
footer .small { font-size: 12px; color: rgba(245, 240, 232, 0.45); }

/* Responsive */
@media (max-width: 720px) {
  .hero { padding: 64px 0 56px; }
  .nav a:not(.cta-link) { display: none; }
}