/* ===== Màu chủ đạo: xanh nước biển + trắng — đổi tại :root ===== */
:root {
  --blue: #0B63CE;
  --blue-dark: #063B7A;
  --blue-deep: #04264F;
  --blue-light: #E8F2FF;
  --cyan: #2EC5FF;
  --white: #FFFFFF;
  --text: #1B2A3D;
  --muted: #5B6B80;
  --border: #D9E6F5;
  --radius: 14px;
  --shadow: 0 10px 30px rgba(11, 99, 206, .12);
}
* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body { font-family: 'Be Vietnam Pro', system-ui, sans-serif; color: var(--text); background: var(--white); line-height: 1.6; }
a { color: inherit; text-decoration: none; }
img, video { max-width: 100%; display: block; }
.container { width: min(1180px, 100% - 32px); margin-inline: auto; }
.center { text-align: center; }
.muted { color: var(--muted); }
h1, h2, h3 { line-height: 1.25; color: var(--blue-deep); }
h2 { font-size: clamp(1.6rem, 3vw, 2.2rem); margin-bottom: 12px; }

/* Buttons */
.btn { display: inline-block; padding: 12px 24px; border-radius: 999px; font-weight: 600; border: 2px solid transparent; cursor: pointer; transition: .2s; font-family: inherit; font-size: 1rem; }
.btn-primary { background: var(--blue); color: #fff; }
.btn-primary:hover { background: var(--blue-dark); transform: translateY(-2px); }
.btn-white { background: #fff; color: var(--blue); }
.btn-white:hover { transform: translateY(-2px); box-shadow: 0 8px 20px rgba(0,0,0,.2); }
.btn-ghost { border-color: rgba(255,255,255,.6); color: #fff; }
.btn-ghost:hover { background: rgba(255,255,255,.12); }
.btn-outline { border-color: var(--blue); color: var(--blue) !important; }
.btn-outline:hover { background: var(--blue); color: #fff !important; }
.btn-sm { padding: 6px 16px; font-size: .9rem; }
.btn-block { width: 100%; }

/* Navbar */
.navbar { position: sticky; top: 0; z-index: 50; background: rgba(255,255,255,.95); backdrop-filter: blur(8px); border-bottom: 1px solid var(--border); transition: box-shadow .2s; }
.navbar.scrolled { box-shadow: 0 4px 20px rgba(4,38,79,.08); }
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 68px; }
.logo { display: flex; align-items: center; gap: 10px; font-weight: 800; font-size: 1.2rem; color: var(--blue-deep); }
.logo-light { color: #fff; }
.logo-mark { background: linear-gradient(135deg, var(--blue), var(--cyan)); color: #fff; width: 38px; height: 38px; border-radius: 10px; display: grid; place-items: center; font-size: .95rem; }
.nav-links { display: flex; align-items: center; gap: 28px; font-weight: 500; }
.nav-links a:not(.btn):hover, .nav-links a.active { color: var(--blue); }
.nav-toggle { display: none; background: none; border: 0; font-size: 1.6rem; color: var(--blue-deep); cursor: pointer; }


/* Chuyển ngôn ngữ VIETNAM / ENGLISH */
.nav-right { display: flex; align-items: center; gap: 12px; }
.lang-switch { display: inline-flex; background: var(--blue-light); border: 1px solid var(--border); border-radius: 999px; padding: 3px; gap: 2px; }
.lang-switch a { padding: 5px 12px; border-radius: 999px; font-size: .78rem; font-weight: 700; letter-spacing: .03em; color: var(--blue-dark); transition: .2s; white-space: nowrap; }
.lang-switch a:hover { color: var(--blue); }
.lang-switch a.on { background: var(--blue); color: #fff !important; box-shadow: 0 2px 8px rgba(11,99,206,.3); }
.lang-switch .flag { font-size: .95rem; }
.lang-mobile { display: none; }

/* Hero */
.hero { background: radial-gradient(circle at 80% 20%, #1478E6 0, transparent 50%), linear-gradient(135deg, var(--blue-deep), var(--blue)); color: #fff; padding: 80px 0 90px; overflow: hidden; }
.hero-grid { display: grid; grid-template-columns: 1.05fr 1fr; gap: 48px; align-items: center; }
.hero h1 { color: #fff; font-size: clamp(2rem, 4.5vw, 3.2rem); margin: 16px 0; }
.hero p { opacity: .9; font-size: 1.1rem; }
.hl { color: var(--cyan); }
.tag { display: inline-block; padding: 6px 14px; border-radius: 999px; background: rgba(255,255,255,.15); font-size: .85rem; font-weight: 600; }
.tag-blue { background: var(--blue-light); color: var(--blue); }
.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; margin: 28px 0 36px; }
.stats { display: flex; gap: 36px; flex-wrap: wrap; }
.stats b { font-size: 2rem; display: block; }
.stats span { opacity: .8; font-size: .9rem; }

/* Video box */
.video-box { position: relative; border-radius: var(--radius); overflow: hidden; background: #021a36; aspect-ratio: 16/9; box-shadow: 0 20px 50px rgba(0,0,0,.25); }
.video-box video { width: 100%; height: 100%; object-fit: cover; position: relative; z-index: 2; }
.video-box.no-video video { display: none; }
.video-placeholder { position: absolute; inset: 0; display: grid; place-items: center; color: #9cc8ff; text-align: center; padding: 20px;
  background-image: linear-gradient(rgba(46,197,255,.08) 1px, transparent 1px), linear-gradient(90deg, rgba(46,197,255,.08) 1px, transparent 1px); background-size: 32px 32px; }
.video-placeholder p { position: absolute; bottom: 14px; font-size: .8rem; }
.video-placeholder code { color: var(--cyan); }
.bbox { width: 38%; height: 55%; border: 2px solid #22ff88; border-radius: 4px; position: relative; animation: float 3s ease-in-out infinite; }
.bbox span { position: absolute; top: -26px; left: -2px; background: #22ff88; color: #02331a; font-size: .75rem; font-weight: 700; padding: 2px 8px; border-radius: 3px; white-space: nowrap; }
.scan-line { position: absolute; left: 0; right: 0; height: 2px; background: linear-gradient(90deg, transparent, var(--cyan), transparent); animation: scan 3s linear infinite; }
.live-badge { position: absolute; top: 12px; right: 12px; z-index: 3; background: rgba(220,30,50,.9); color: #fff; font-size: .72rem; font-weight: 700; padding: 3px 10px; border-radius: 999px; }
@keyframes scan { from { top: 0 } to { top: 100% } }
@keyframes float { 50% { transform: translate(18px, -8px) } }

/* Sections */
.section { padding: 84px 0; }
.section-alt { background: var(--blue-light); }
.section-head { text-align: center; max-width: 680px; margin: 0 auto 48px; }
.section-head .tag { margin-bottom: 12px; }
.section-head p { color: var(--muted); }

/* Cards */
.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 22px; }
.cards-3 { margin-top: 32px; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); }
.card { background: #fff; border: 1px solid var(--border); border-radius: var(--radius); padding: 26px; transition: .25s; display: flex; flex-direction: column; }
.card:hover { transform: translateY(-6px); box-shadow: var(--shadow); border-color: var(--blue); }
.card h3 { font-size: 1.1rem; margin: 14px 0 8px; }
.card p { color: var(--muted); font-size: .95rem; flex: 1; }
.card .more { color: var(--blue); font-weight: 600; margin-top: 14px; font-size: .9rem; }
.card-icon { width: 54px; height: 54px; border-radius: 14px; background: var(--blue-light); display: grid; place-items: center; font-size: 1.6rem; }

/* Demo tabs */
.demo-tabs { display: flex; gap: 10px; flex-wrap: wrap; justify-content: center; margin-bottom: 32px; }
.demo-tabs button { border: 1px solid var(--border); background: #fff; padding: 9px 16px; border-radius: 999px; cursor: pointer; font-family: inherit; font-size: .9rem; color: var(--text); transition: .2s; }
.demo-tabs button:hover { border-color: var(--blue); }
.demo-tabs button.active { background: var(--blue); color: #fff; border-color: var(--blue); }
.demo-panel { display: none; grid-template-columns: 1.3fr 1fr; gap: 40px; align-items: center; }
.demo-panel.active { display: grid; animation: fade .4s; }
.demo-info p { color: var(--muted); margin: 10px 0 16px; }
@keyframes fade { from { opacity: 0; transform: translateY(10px) } }

.checklist { list-style: none; margin: 16px 0 24px; }
.checklist li { padding-left: 28px; position: relative; margin-bottom: 8px; }
.checklist li::before { content: '✓'; position: absolute; left: 0; width: 20px; height: 20px; border-radius: 50%; background: var(--blue); color: #fff; font-size: .7rem; display: grid; place-items: center; top: 3px; }

/* Steps */
.steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 22px; }
.step { padding: 28px; border-radius: var(--radius); border: 1px solid var(--border); }
.step b { font-size: 2.2rem; color: var(--blue); opacity: .3; }
.step h4 { font-size: 1.1rem; color: var(--blue-deep); margin: 6px 0; }
.step p { color: var(--muted); font-size: .93rem; }

/* CTA */
.cta { background: linear-gradient(135deg, var(--blue), var(--blue-deep)); color: #fff; padding: 60px 0; }
.cta-inner { display: flex; justify-content: space-between; align-items: center; gap: 24px; flex-wrap: wrap; }
.cta h2 { color: #fff; }

/* Page hero */
.page-hero { background: linear-gradient(135deg, var(--blue-deep), var(--blue)); color: #fff; padding: 60px 0; }
.page-hero h1 { color: #fff; font-size: clamp(1.8rem, 4vw, 2.6rem); }
.page-hero p { opacity: .9; margin-top: 8px; }
.back { display: inline-block; margin-bottom: 12px; opacity: .85; }

.service-row { display: grid; grid-template-columns: 1.2fr 1fr; gap: 48px; align-items: center; margin-bottom: 72px; }
.service-row:last-child { margin-bottom: 0; }
.service-row.reverse > .video-box { order: 2; }
.service-row h2 { margin-top: 14px; }
.service-row p { color: var(--muted); }

/* Forms */
.contact-grid { display: grid; grid-template-columns: 1fr 1.5fr; gap: 48px; }
.contact-info p { margin: 10px 0; }
.note { margin-top: 24px; padding: 18px; background: var(--blue-light); border-left: 4px solid var(--blue); border-radius: 8px; }
.form { display: grid; gap: 16px; background: #fff; padding: 32px; border-radius: var(--radius); border: 1px solid var(--border); box-shadow: var(--shadow); }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.form label { display: grid; gap: 6px; font-weight: 500; font-size: .92rem; }
.form input, .form select, .form textarea { padding: 12px 14px; border: 1px solid var(--border); border-radius: 10px; font-family: inherit; font-size: 1rem; }
.form input:focus, .form select:focus, .form textarea:focus { outline: none; border-color: var(--blue); box-shadow: 0 0 0 3px var(--blue-light); }
.form-msg { font-weight: 500; }
.form-msg.ok { color: #0a8a4a; } .form-msg.err { color: #c62828; }
.login-wrap { background: var(--blue-light); }
.login-box { max-width: 420px; margin: 0 auto; }

/* Footer */
.footer { background: var(--blue-deep); color: #c7d8ee; padding: 56px 0 0; }
.footer-grid { display: grid; grid-template-columns: 1.5fr 1fr 1fr; gap: 32px; }
.footer h4 { color: #fff; margin-bottom: 12px; }
.footer a:not(.logo) { display: block; margin-bottom: 6px; }
.footer a:hover { color: #fff; }
.footer p { margin-bottom: 6px; }
.muted-light { opacity: .7; margin-top: 12px; }
.copyright { border-top: 1px solid rgba(255,255,255,.1); margin-top: 40px; padding: 18px 0; font-size: .85rem; opacity: .7; }

/* Reveal animation */
.reveal { opacity: 0; transform: translateY(24px); transition: .6s; }
.reveal.show { opacity: 1; transform: none; }

/* Responsive */
@media (max-width: 900px) {
  .hero-grid, .demo-panel.active, .service-row, .contact-grid { grid-template-columns: 1fr; }
  .service-row.reverse > .video-box { order: 0; }
  .steps { grid-template-columns: 1fr 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .nav-toggle { display: block; }
  .lang-mobile { display: inline-flex; }
  .lang-desktop { display: none; }
  .nav-links { display: none; position: absolute; top: 68px; left: 0; right: 0; background: #fff; flex-direction: column; padding: 20px; gap: 16px; border-bottom: 1px solid var(--border); }
  .nav-links.open { display: flex; }
}
@media (max-width: 560px) {
  .steps, .form-row { grid-template-columns: 1fr; }
  .section { padding: 60px 0; }
  .form { padding: 22px; }
}
.video-box:not(.no-video) .live-badge { display: none; }