:root {
  --navy: #0f1b3d;
  --ink: #1e293b;
  --muted: #64748b;
  --bg: #f4f6fb;
  --card: #ffffff;
  --violet: #6d28d9;
  --cyan: #06b6d4;
  --gold: #f59e0b;
  --radius: 14px;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body { font-family: "Segoe UI", system-ui, -apple-system, Roboto, Arial, sans-serif; color: var(--ink); background: var(--bg); line-height: 1.6; }
.container { max-width: 1140px; margin: 0 auto; padding: 0 18px; }
.container.narrow { max-width: 820px; }
img { max-width: 100%; }

/* Topbar + header */
.topbar { background: var(--navy); color: #fff; font-size: 13.5px; padding: 8px 0; }
.topbar .container { display: flex; justify-content: space-between; align-items: center; gap: 10px; flex-wrap: wrap; }
.topbar a.tel { color: #fff; font-weight: 700; text-decoration: none; }
.btn-zalo { display: inline-block; background: #0068ff; color: #fff !important; padding: 6px 16px; border-radius: 18px; text-decoration: none; font-weight: 700; font-size: 13.5px; }
.btn-call { display: inline-block; background: var(--gold); color: #fff !important; padding: 6px 16px; border-radius: 18px; text-decoration: none; font-weight: 700; font-size: 13.5px; }
header.site { background: #fff; box-shadow: 0 2px 12px rgba(15,27,61,.08); position: sticky; top: 0; z-index: 50; }
header.site .container { display: flex; justify-content: space-between; align-items: center; padding-top: 12px; padding-bottom: 12px; }
.logo { font-size: 22px; font-weight: 800; color: var(--navy); line-height: 1.1; }
.logo small { display: block; font-size: 10.5px; font-weight: 600; color: var(--violet); letter-spacing: 1.5px; }
nav.main { display: flex; gap: 20px; }
nav.main a { color: var(--ink); text-decoration: none; font-weight: 600; font-size: 15px; }
nav.main a:hover { color: var(--violet); }

/* Hero */
.hero { background: linear-gradient(135deg, #1e1b4b 0%, #4c1d95 55%, #0e7490 100%); color: #fff; padding: 72px 0 64px; text-align: center; }
.hero-in h1 { font-size: clamp(30px, 5vw, 54px); line-height: 1.3; margin-bottom: 16px; }
.hero-in h1 span { background: linear-gradient(90deg, #22d3ee, #a78bfa); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero-sub { font-size: 18px; opacity: .92; margin-bottom: 30px; }
.hero-sub b { color: #fde68a; }
.hero-cta { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; margin-bottom: 44px; }
.btn { display: inline-block; padding: 13px 30px; border-radius: 30px; font-weight: 800; font-size: 16px; text-decoration: none; }
.btn-gold { background: linear-gradient(90deg, #f59e0b, #f97316); color: #fff; box-shadow: 0 6px 20px rgba(249,115,22,.4); }
.btn-outline { border: 2px solid rgba(255,255,255,.7); color: #fff; }
.hero-stats { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }
.hstat { background: rgba(255,255,255,.12); border: 1px solid rgba(255,255,255,.22); border-radius: 12px; padding: 12px 26px; }
.hstat b { display: block; font-size: 24px; }
.hstat span { font-size: 13px; opacity: .85; }

/* Sections */
.block { padding: 64px 0; }
.block.alt { background: #fff; }
.sec-title { text-align: center; font-size: clamp(24px, 3.4vw, 34px); color: var(--navy); margin-bottom: 8px; }
.sec-sub { text-align: center; color: var(--muted); margin-bottom: 36px; }

/* Pricing */
.price-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 20px; }
.price-card { background: var(--card); border: 2px solid #e2e8f0; border-radius: var(--radius); padding: 28px 24px; text-align: center; position: relative; display: flex; flex-direction: column; }
.price-card.hot { border-color: var(--violet); box-shadow: 0 12px 34px rgba(109,40,217,.18); transform: scale(1.03); }
.p-badge { position: absolute; top: -14px; left: 50%; transform: translateX(-50%); background: var(--violet); color: #fff; font-size: 12px; font-weight: 800; padding: 4px 16px; border-radius: 14px; white-space: nowrap; }
.price-card h3 { color: var(--navy); font-size: 19px; letter-spacing: 1px; margin-bottom: 6px; }
.p-price { font-size: 32px; font-weight: 800; color: var(--violet); }
.p-note { font-size: 13px; color: var(--muted); margin-bottom: 18px; }
.price-card ul { list-style: none; text-align: left; margin-bottom: 24px; flex: 1; }
.price-card ul li { padding: 7px 0; border-bottom: 1px dashed #e2e8f0; font-size: 14.5px; }
.price-card ul li::before { content: "✓ "; color: #16a34a; font-weight: 800; }
.price-card .btn-outline { border-color: var(--violet); color: var(--violet); }
.price-foot { text-align: center; color: var(--muted); font-size: 13.5px; margin-top: 22px; }

/* Steps */
.steps { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 18px; }
.step { background: var(--bg); border-radius: var(--radius); padding: 24px 18px; text-align: center; }
.step-n { width: 46px; height: 46px; border-radius: 50%; background: linear-gradient(135deg, var(--violet), var(--cyan)); color: #fff; font-weight: 800; font-size: 20px; display: flex; align-items: center; justify-content: center; margin: 0 auto 12px; }
.step b { color: var(--navy); display: block; margin-bottom: 6px; }
.step p { font-size: 14px; color: var(--muted); }

/* Demo */
.demo-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 20px; }
.demo-card { background: var(--card); border: 1px solid #e2e8f0; border-radius: var(--radius); padding: 24px; text-decoration: none; color: var(--ink); display: block; transition: transform .2s; }
.demo-card:hover { transform: translateY(-4px); box-shadow: 0 10px 26px rgba(15,27,61,.1); }
.demo-thumb { font-size: 46px; text-align: center; border-radius: 10px; padding: 26px; margin-bottom: 14px; }
.demo-paint { background: linear-gradient(135deg, #fef3c7, #fde68a); }
.demo-brand { background: linear-gradient(135deg, #ede9fe, #c4b5fd); }
.demo-more { background: linear-gradient(135deg, #e0f2fe, #a5f3fc); }
.demo-card b { color: var(--navy); display: block; margin-bottom: 6px; }
.demo-card p { font-size: 14px; color: var(--muted); margin-bottom: 10px; }
.demo-link { color: var(--violet); font-weight: 700; font-size: 14.5px; }

/* Why */
.why-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 20px; }
.why { background: var(--bg); border-radius: var(--radius); padding: 26px 22px; text-align: center; }
.why-i { font-size: 38px; margin-bottom: 10px; }
.why b { color: var(--navy); display: block; margin-bottom: 6px; }
.why p { font-size: 14.5px; color: var(--muted); }

/* FAQ */
.faq { background: var(--card); border: 1px solid #e2e8f0; border-radius: 10px; margin-bottom: 12px; overflow: hidden; }
.faq-q { width: 100%; background: none; border: none; padding: 16px 20px; font-size: 16px; font-weight: 700; color: var(--navy); display: flex; justify-content: space-between; align-items: center; cursor: pointer; text-align: left; }
.faq-q span { color: var(--violet); font-size: 20px; }
.faq-a { max-height: 0; overflow: hidden; transition: max-height .3s ease; padding: 0 20px; color: var(--muted); font-size: 15px; }
.faq.open .faq-a { max-height: 220px; padding-bottom: 16px; }

/* Contact */
.contact-cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 18px; margin-top: 26px; }
.contact-card { background: var(--bg); border-radius: 12px; padding: 22px; text-align: center; }
.block.alt .contact-card { background: #f4f6fb; }
.contact-card .big { font-size: 26px; font-weight: 800; color: var(--navy); margin: 8px 0; }
.contact-card.email-card { grid-column: 1 / -1; padding: 14px 20px; }
.contact-card.email-card .email-addr { font-size: 16px; font-weight: 800; color: var(--navy); margin: 6px 0; white-space: nowrap; }
.faq-list { margin-top: 6px; }

/* Footer */
footer { background: var(--navy); color: #cbd5e1; text-align: center; padding: 34px 18px; font-size: 14.5px; line-height: 2; }
footer strong { color: #fff; }

/* Chatbot */
#chat-fab { position: fixed; right: 20px; bottom: 20px; width: 58px; height: 58px; border-radius: 50%; border: none; background: linear-gradient(135deg, var(--violet), var(--cyan)); font-size: 26px; cursor: pointer; box-shadow: 0 8px 22px rgba(109,40,217,.4); z-index: 99; }
#chat-box { position: fixed; right: 20px; bottom: 90px; width: 340px; max-width: calc(100vw - 40px); height: 460px; max-height: 70vh; background: #fff; border-radius: 16px; box-shadow: 0 14px 44px rgba(15,27,61,.25); display: none; flex-direction: column; overflow: hidden; z-index: 99; }
#chat-box.open { display: flex; }
#chat-head { background: linear-gradient(90deg, var(--violet), var(--cyan)); color: #fff; padding: 12px 16px; font-weight: 800; display: flex; justify-content: space-between; align-items: center; }
#chat-close { background: none; border: none; color: #fff; font-size: 22px; cursor: pointer; }
#chat-msgs { flex: 1; overflow-y: auto; padding: 14px; display: flex; flex-direction: column; gap: 10px; }
.msg { max-width: 88%; padding: 9px 13px; border-radius: 14px; font-size: 14px; line-height: 1.55; }
.msg.bot { background: #f1f5f9; align-self: flex-start; }
.msg.user { background: var(--violet); color: #fff; align-self: flex-end; }
.msg a { color: var(--violet); }
#chat-quick { display: flex; gap: 8px; flex-wrap: wrap; padding: 0 14px 10px; }
#chat-quick button { background: #ede9fe; border: none; color: var(--violet); font-size: 12.5px; font-weight: 700; padding: 7px 12px; border-radius: 16px; cursor: pointer; }
#chat-form { display: flex; border-top: 1px solid #e2e8f0; }
#chat-input { flex: 1; border: none; padding: 13px 14px; font-size: 14px; outline: none; }
#chat-form button { border: none; background: var(--violet); color: #fff; padding: 0 18px; font-size: 17px; cursor: pointer; }
.lead-form input, .lead-form textarea { width: 100%; border: 1px solid #cbd5e1; border-radius: 8px; padding: 8px 10px; margin-top: 8px; font-size: 13.5px; font-family: inherit; }
.lead-form button { margin-top: 10px; background: var(--violet); color: #fff; border: none; border-radius: 18px; padding: 9px 22px; font-weight: 800; cursor: pointer; }

@keyframes blinkz { 0%, 100% { opacity: 1; } 50% { opacity: .55; } }

@media (max-width: 760px) {
  nav.main { display: none; }
  .contact-card.email-card .email-addr { font-size: 13.5px; }
  .price-card.hot { transform: none; }
}