:root {
  --ink: #12141c;
  --ink-2: #3a4050;
  --muted: #6b7282;
  --line: #e7e9f0;
  --soft: #f6f6fb;
  --brand: #6352f0;
  --brand-2: #4c3cdc;
  --brand-soft: #efedff;
  --ok: #12805a;
  --fb: #1877f2;
  --zalo: #0068ff;
  --font: 'Be Vietnam Pro', Inter, system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; font: 16px/1.6 var(--font); color: var(--ink); background: #fff; -webkit-font-smoothing: antialiased; }
a { color: inherit; text-decoration: none; }
img, svg { display: block; }
h1, h2, h3 { margin: 0; letter-spacing: -0.025em; line-height: 1.15; }
p { margin: 0; }
.wrap { max-width: 1160px; margin: 0 auto; padding: 0 20px; }
.muted { color: var(--muted); }

/* Header */
.site-header { position: sticky; top: 0; z-index: 20; background: rgba(255,255,255,.88); backdrop-filter: saturate(1.6) blur(12px); border-bottom: 1px solid transparent; transition: border-color .2s; }
.site-header.scrolled { border-bottom-color: var(--line); }
.nav { height: 68px; display: flex; align-items: center; justify-content: space-between; gap: 20px; }
.brand { display: flex; align-items: center; gap: 10px; font-size: 22px; font-weight: 800; letter-spacing: -0.04em; }
.brand b { color: var(--brand); font-weight: 800; }
.logo { width: 32px; height: 32px; border-radius: 10px; background: linear-gradient(135deg, #7c70ff, #4c3cdc); color: #fff; display: grid; place-items: center; font-size: 16px; }
.links { display: flex; align-items: center; gap: 28px; font-size: 14.5px; color: var(--ink-2); font-weight: 500; }
.links a:not(.btn):hover { color: var(--brand); }
.nav-cta { display: flex; gap: 8px; align-items: center; }
.menu-btn { display: none; border: 0; background: none; width: 40px; height: 40px; border-radius: 10px; cursor: pointer; }
.menu-btn span { display: block; width: 20px; height: 2px; background: var(--ink); margin: 4px auto; border-radius: 2px; }

.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; border-radius: 12px; padding: 12px 20px; font-weight: 650; font-size: 15px; border: 1px solid transparent; cursor: pointer; transition: background .15s, border-color .15s, transform .15s; white-space: nowrap; font-family: inherit; }
.btn:active { transform: translateY(1px); }
.btn-primary { background: var(--brand); color: #fff; box-shadow: 0 6px 20px rgba(99,82,240,.28); }
.btn-primary:hover { background: var(--brand-2); }
.btn-ghost { border-color: var(--line); background: #fff; }
.btn-ghost:hover { border-color: #cfd2dc; }
.btn-sm { padding: 9px 14px; font-size: 14px; border-radius: 10px; box-shadow: none; }
.btn-light { background: #fff; color: var(--ink); }

/* Hero */
.hero { padding: 72px 0 80px; background: radial-gradient(900px 400px at 85% 0%, #f0eeff 0%, transparent 70%); }
.hero-grid { display: grid; grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr); gap: 56px; align-items: center; }
.eyebrow { display: inline-flex; align-items: center; gap: 8px; font-size: 13px; font-weight: 700; color: var(--brand-2); background: var(--brand-soft); padding: 6px 12px; border-radius: 99px; }
.hero h1 { font-size: clamp(36px, 5.2vw, 58px); font-weight: 800; margin: 18px 0 20px; }
.hero h1 em { font-style: normal; background: linear-gradient(90deg, #6352f0, #a35cf0); -webkit-background-clip: text; background-clip: text; color: transparent; }
.lead { font-size: 18.5px; color: var(--ink-2); max-width: 560px; }
.actions { display: flex; gap: 12px; margin-top: 32px; flex-wrap: wrap; }
.trust { display: flex; gap: 20px; margin-top: 24px; font-size: 14px; color: var(--muted); flex-wrap: wrap; }
.trust span::before { content: '✓'; color: var(--ok); font-weight: 700; margin-right: 6px; }

/* Flow mock */
.mock { position: relative; display: grid; gap: 14px; }
.mock-card { background: #fff; border: 1px solid var(--line); border-radius: 18px; padding: 16px; box-shadow: 0 20px 50px rgba(30, 30, 70, .08); }
.mock-label { display: flex; align-items: center; gap: 8px; font-size: 12.5px; font-weight: 700; color: var(--muted); margin-bottom: 12px; }
.dot { width: 22px; height: 22px; border-radius: 7px; display: grid; place-items: center; color: #fff; font-size: 11px; font-weight: 800; }
.dot.zl { background: var(--zalo); }
.dot.ai { background: var(--brand); }
.dot.fb { background: var(--fb); }
.bubble { background: #eef4ff; border-radius: 14px 14px 14px 4px; padding: 10px 12px; font-size: 13.5px; line-height: 1.5; max-width: 92%; }
.bubble s { color: #c0392b; text-decoration-thickness: 2px; }
.thumbs { display: flex; gap: 6px; margin-top: 8px; }
.thumbs i { width: 52px; height: 52px; border-radius: 10px; background: linear-gradient(135deg, #dfe7ff, #c7d5ff); }
.thumbs i:nth-child(2) { background: linear-gradient(135deg, #ffe3d6, #ffc7b0); }
.thumbs i:nth-child(3) { background: linear-gradient(135deg, #dcf5e8, #b8eacd); }
.ai-steps { display: flex; flex-wrap: wrap; gap: 6px; }
.ai-steps span { font-size: 12.5px; font-weight: 600; padding: 5px 10px; border-radius: 99px; background: var(--brand-soft); color: var(--brand-2); }
.fb-post-head { display: flex; gap: 10px; align-items: center; margin-bottom: 8px; }
.fb-avatar { width: 34px; height: 34px; border-radius: 50%; background: #ffd9a8; display: grid; place-items: center; font-weight: 800; font-size: 13px; color: #8a4b00; }
.fb-post-head b { font-size: 14px; display: block; }
.fb-post-head small { font-size: 12px; color: var(--muted); }
.fb-text { font-size: 13.5px; line-height: 1.55; }
.fb-text mark { background: #e7f7ef; color: var(--ok); border-radius: 4px; padding: 0 3px; font-weight: 600; }
.sched { position: absolute; right: -10px; top: 46%; background: #12141c; color: #fff; font-size: 12.5px; font-weight: 600; padding: 8px 12px; border-radius: 10px; box-shadow: 0 10px 24px rgba(0,0,0,.2); }

/* Sections */
.section { padding: 96px 0; }
.section-alt { background: var(--soft); }
.section-head { max-width: 680px; margin-bottom: 48px; }
.section-head.center { margin-left: auto; margin-right: auto; text-align: center; }
.kicker { font-size: 13px; font-weight: 700; color: var(--brand); text-transform: uppercase; letter-spacing: .1em; margin-bottom: 12px; }
.section h2 { font-size: clamp(28px, 3.6vw, 40px); font-weight: 800; }
.section-head p { margin-top: 14px; font-size: 17px; color: var(--muted); }

.pains { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 20px; }
.pain { border: 1px solid var(--line); border-radius: 18px; padding: 26px; background: #fff; }
.pain .num { font-size: 13px; font-weight: 800; color: #d4573b; margin-bottom: 10px; }
.pain h3 { font-size: 18px; margin-bottom: 8px; }
.pain p { color: var(--muted); font-size: 15px; }

.steps { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 20px; counter-reset: step; }
.step { position: relative; background: #fff; border: 1px solid var(--line); border-radius: 18px; padding: 26px 22px; }
.step::before { counter-increment: step; content: counter(step); width: 36px; height: 36px; border-radius: 11px; background: var(--brand); color: #fff; display: grid; place-items: center; font-weight: 800; margin-bottom: 18px; }
.step h3 { font-size: 17px; margin-bottom: 8px; }
.step p { color: var(--muted); font-size: 14.5px; }

.features { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 28px 32px; }
.feature .ico { width: 44px; height: 44px; border-radius: 12px; background: var(--brand-soft); color: var(--brand-2); display: grid; place-items: center; margin-bottom: 16px; }
.feature h3 { font-size: 17px; margin-bottom: 8px; }
.feature p { color: var(--muted); font-size: 15px; }

.own { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 48px; align-items: center; background: #12141c; color: #fff; border-radius: 28px; padding: 56px; }
.own h2 { color: #fff; }
.own p { color: #b9bccb; margin-top: 14px; font-size: 16.5px; }
.own ul { list-style: none; padding: 0; margin: 0; display: grid; gap: 14px; }
.own li { display: flex; gap: 12px; background: rgba(255,255,255,.06); border: 1px solid rgba(255,255,255,.08); padding: 16px 18px; border-radius: 14px; font-size: 15px; color: #e7e8f0; }
.own li b { color: #fff; display: block; margin-bottom: 2px; }
.own li::before { content: '✓'; color: #8ef0c3; font-weight: 800; }

.pricing { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 20px; max-width: 1000px; margin: 0 auto; }
.price { border: 1px solid var(--line); border-radius: 20px; padding: 28px; display: flex; flex-direction: column; gap: 12px; background: #fff; }
.price.featured { border: 2px solid var(--brand); box-shadow: 0 20px 50px rgba(99,82,240,.14); position: relative; }
.price.featured::after { content: 'Phổ biến'; position: absolute; top: -13px; left: 24px; background: var(--brand); color: #fff; font-size: 12px; font-weight: 700; padding: 4px 10px; border-radius: 99px; }
.price h3 { font-size: 19px; }
.price .amount { font-size: 34px; font-weight: 800; letter-spacing: -0.03em; }
.price .amount span { font-size: 15px; color: var(--muted); font-weight: 500; }
.price ul { list-style: none; padding: 0; margin: 6px 0 12px; display: grid; gap: 10px; font-size: 15px; }
.price li::before { content: '✓'; color: var(--ok); font-weight: 800; margin-right: 10px; }
.price .btn { margin-top: auto; }
.pricing-note { text-align: center; color: var(--muted); font-size: 14.5px; margin-top: 24px; }

.faq { max-width: 780px; margin: 0 auto; display: grid; gap: 12px; }
.faq details { border: 1px solid var(--line); border-radius: 14px; padding: 4px 22px; background: #fff; }
.faq summary { cursor: pointer; font-weight: 650; font-size: 16.5px; padding: 16px 0; list-style: none; display: flex; justify-content: space-between; gap: 16px; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: '+'; font-size: 22px; color: var(--brand); line-height: 1; }
.faq details[open] summary::after { content: '–'; }
.faq details p { color: var(--ink-2); padding: 0 0 18px; font-size: 15.5px; }

.cta { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 48px; align-items: center; background: linear-gradient(140deg, #6352f0, #3b2db8); color: #fff; border-radius: 28px; padding: 56px; }
.cta h2 { color: #fff; }
.cta p { color: #dcd8ff; margin-top: 14px; font-size: 17px; }
.cta .actions { margin-top: 26px; }
.form { background: #fff; color: var(--ink); border-radius: 20px; padding: 26px; display: grid; gap: 12px; }
.form h3 { font-size: 18px; }
.form .row { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.form label { display: grid; gap: 6px; font-size: 13px; font-weight: 600; color: var(--ink-2); }
.form input, .form textarea { width: 100%; border: 1px solid var(--line); border-radius: 10px; padding: 11px 12px; font: inherit; font-size: 15px; }
.form input:focus, .form textarea:focus { outline: none; border-color: #a49bff; box-shadow: 0 0 0 3px rgba(99,82,240,.14); }
.form .hp { position: absolute; left: -9999px; }
.form-msg { font-size: 14px; min-height: 20px; }
.form-msg.ok { color: var(--ok); }
.form-msg.err { color: #c23b3b; }

.site-footer { border-top: 1px solid var(--line); padding: 48px 0 32px; margin-top: 96px; font-size: 14.5px; color: var(--muted); }
.foot-grid { display: grid; grid-template-columns: 1.6fr 1fr 1fr; gap: 32px; }
.foot-grid h4 { margin: 0 0 12px; color: var(--ink); font-size: 14.5px; }
.foot-grid a { display: block; padding: 4px 0; }
.foot-grid a:hover { color: var(--brand); }
.copyright { margin-top: 36px; padding-top: 20px; border-top: 1px solid var(--line); font-size: 13.5px; }

/* Legal pages */
.legal { max-width: 780px; margin: 0 auto; padding: 64px 20px 0; }
.legal h1 { font-size: 36px; margin-bottom: 8px; }
.legal .updated { color: var(--muted); margin-bottom: 36px; }
.legal h2 { font-size: 21px; margin: 36px 0 12px; }
.legal p, .legal li { color: var(--ink-2); font-size: 16px; }
.legal p { margin: 0 0 12px; }
.legal ul, .legal ol { padding-left: 22px; margin: 0 0 12px; }
.legal li { margin-bottom: 6px; }
.legal .box { background: var(--soft); border-radius: 14px; padding: 18px 22px; margin: 20px 0; }

@media (max-width: 960px) {
  .hero-grid, .own, .cta { grid-template-columns: minmax(0, 1fr); }
  .hero { padding-top: 48px; }
  .steps { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .features, .pains { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .own, .cta { padding: 36px 24px; gap: 32px; }
  .sched { right: 8px; }
}
@media (max-width: 760px) {
  .menu-btn { display: block; }
  .links { display: none; position: absolute; top: 68px; left: 0; right: 0; background: #fff; flex-direction: column; align-items: stretch; gap: 0; padding: 8px 16px 16px; border-bottom: 1px solid var(--line); box-shadow: 0 16px 30px rgba(0,0,0,.06); }
  .links.open { display: flex; }
  .links a:not(.btn) { padding: 12px 4px; border-bottom: 1px solid var(--line); }
  .links .btn { margin-top: 12px; }
  .nav-cta .btn-ghost { display: none; }
  .section { padding: 64px 0; }
  .steps, .features, .pains { grid-template-columns: minmax(0, 1fr); }
  .foot-grid { grid-template-columns: 1fr 1fr; }
  .foot-grid > div:first-child { grid-column: 1 / -1; }
  .form .row { grid-template-columns: minmax(0, 1fr); }
  .lead { font-size: 17px; }
  .actions .btn { flex: 1; }
  .legal h1 { font-size: 28px; }
}

/* Trang đăng ký */
.signup-page { padding: 64px 0 0; background: radial-gradient(900px 400px at 85% 0%, #f0eeff 0%, transparent 70%); }
.signup-grid { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 480px); gap: 56px; align-items: start; }
.signup-intro h1 { font-size: clamp(30px, 4vw, 44px); font-weight: 800; margin: 18px 0 16px; }
.signup-points { list-style: none; padding: 0; margin: 28px 0 0; display: grid; gap: 12px; font-size: 16px; }
.signup-points li::before { content: '✓'; color: var(--ok); font-weight: 800; margin-right: 10px; }
.signup-form { border: 1px solid var(--line); box-shadow: 0 20px 50px rgba(30, 30, 70, .08); }
.form-note { font-size: 13.5px; color: var(--muted); text-align: center; }
.form-note a { color: var(--brand); font-weight: 600; }
@media (max-width: 860px) {
  .signup-page { padding-top: 36px; }
  .signup-grid { grid-template-columns: minmax(0, 1fr); gap: 32px; }
}