:root {
  --red: #da251d;
  --red-dark: #b81e17;
  --red-soft: #fef2f2;
  --gold: #ffd700;
  --gold-dark: #e6c200;
  --navy: #1a3a5c;
  --navy-light: #2a5080;
  --white: #ffffff;
  --gray-50: #f7f8fa;
  --gray-100: #eef0f4;
  --gray-200: #dde1e8;
  --gray-400: #8b95a5;
  --gray-600: #4a5568;
  --gray-800: #1e2530;
  --shadow: 0 4px 24px rgba(26, 58, 92, 0.08);
  --shadow-lg: 0 12px 40px rgba(26, 58, 92, 0.12);
  --radius: 8px;
  --radius-lg: 12px;
  --max: 1180px;
  --font: "Be Vietnam Pro", system-ui, sans-serif;
  --font-display: "Lexend", "Be Vietnam Pro", sans-serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body { font-family: var(--font); color: var(--gray-800); background: var(--white); line-height: 1.65; -webkit-font-smoothing: antialiased; }
h1, h2, h3, h4 { font-family: var(--font-display); line-height: 1.2; letter-spacing: -0.01em; }
.container { width: 100%; max-width: var(--max); margin: 0 auto; padding: 0 24px; }
a { text-decoration: none; color: inherit; }

/* Top bar - VN corporate standard */
.topbar { background: var(--navy); color: rgba(255,255,255,.88); font-size: 13px; padding: 10px 0; font-weight: 500; }
.topbar-inner { display: flex; justify-content: center; align-items: center; gap: 28px; flex-wrap: wrap; }
.topbar a { color: rgba(255,255,255,.92); transition: color .15s; }
.topbar a:hover { color: var(--gold); }

/* Buttons */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  gap: 8px; font-weight: 600; font-size: 14px; font-family: var(--font);
  padding: 11px 22px; border-radius: var(--radius); cursor: pointer;
  border: none; transition: all .2s;
}
.btn-lg { padding: 14px 28px; font-size: 15px; }
.btn-block { width: 100%; }
.btn-primary { background: var(--red); color: #fff; box-shadow: 0 4px 14px rgba(218,37,29,.3); }
.btn-primary:hover { background: var(--red-dark); transform: translateY(-1px); }
.btn-outline { background: transparent; border: 2px solid var(--gray-200); color: var(--gray-800); }
.btn-outline:hover { border-color: var(--red); color: var(--red); }
.btn-outline-light { background: transparent; border: 2px solid rgba(255,255,255,.45); color: #fff; }
.btn-outline-light:hover { border-color: #fff; background: rgba(255,255,255,.1); }

.section-label {
  display: inline-block; font-size: 12px; font-weight: 700;
  letter-spacing: .14em; text-transform: uppercase;
  color: var(--red); margin-bottom: 10px;
}

/* Navbar */
.navbar {
  position: sticky; top: 0; z-index: 200;
  background: var(--white); border-bottom: 1px solid var(--gray-200);
  padding: 14px 0; transition: box-shadow .25s;
}
.navbar.scrolled { box-shadow: var(--shadow); }
.nav-inner { display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.brand { display: flex; align-items: center; gap: 12px; flex-shrink: 0; }
.brand-mark {
  width: 44px; height: 44px; border-radius: var(--radius);
  background: linear-gradient(135deg, var(--red), var(--red-dark));
  color: #fff; display: grid; place-items: center;
  font-weight: 800; font-size: 13px; letter-spacing: -.02em;
}
.brand-text { display: flex; flex-direction: column; line-height: 1.15; }
.brand-name { font-family: var(--font-display); font-size: 18px; font-weight: 700; color: var(--navy); }
.brand-sub { font-size: 11px; font-weight: 600; color: var(--gray-400); letter-spacing: .04em; }
.nav-links { display: flex; gap: 28px; }
.nav-links a { color: var(--gray-600); font-weight: 600; font-size: 15px; transition: color .15s; }
.nav-links a:hover { color: var(--red); }
.nav-actions { display: flex; align-items: center; gap: 10px; flex-shrink: 0; }

/* Language switcher */
.lang-switcher { position: relative; }
.lang-trigger {
  display: flex; align-items: center; gap: 7px;
  padding: 9px 14px; border-radius: var(--radius);
  border: 2px solid var(--red); background: var(--red-soft);
  color: var(--red); font-weight: 700; font-size: 14px; cursor: pointer; min-width: 96px;
}
.lang-trigger:hover { background: var(--red); color: #fff; }
.lang-flag { font-size: 16px; }
.lang-chevron { font-size: 10px; transition: transform .2s; }
.lang-switcher.open .lang-chevron { transform: rotate(180deg); }
.lang-dropdown {
  position: absolute; top: calc(100% + 6px); right: 0; min-width: 190px;
  background: var(--white); border: 1px solid var(--gray-200);
  border-radius: var(--radius); box-shadow: var(--shadow-lg); list-style: none;
  opacity: 0; visibility: hidden; transform: translateY(-6px); transition: all .2s; z-index: 300;
}
.lang-switcher.open .lang-dropdown { opacity: 1; visibility: visible; transform: none; }
.lang-dropdown li {
  display: flex; align-items: center; gap: 10px; padding: 12px 16px;
  cursor: pointer; font-weight: 600; font-size: 14px; border-bottom: 1px solid var(--gray-100);
}
.lang-dropdown li:last-child { border-bottom: none; }
.lang-dropdown li:hover, .lang-dropdown li.active { background: var(--red-soft); color: var(--red); }
.lang-dropdown li small { margin-left: auto; font-size: 11px; color: var(--gray-400); font-weight: 700; }

.nav-toggle { display: none; flex-direction: column; gap: 5px; background: none; border: 0; cursor: pointer; }
.nav-toggle span { width: 24px; height: 2px; background: var(--navy); border-radius: 2px; }

/* Hero */
.hero {
  position: relative; background: linear-gradient(135deg, var(--navy) 0%, var(--navy-light) 100%);
  color: #fff; padding: 72px 0 80px; overflow: hidden;
}
.hero-pattern {
  position: absolute; inset: 0;
  background: url("data:image/svg+xml,%3Csvg width='40' height='40' viewBox='0 0 40 40' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='%23ffffff' fill-opacity='0.04'%3E%3Cpath d='M0 0h20v20H0V0zm20 20h20v20H20V20z'/%3E%3C/g%3E%3C/svg%3E");
}
.hero-inner { position: relative; display: grid; grid-template-columns: 1.15fr .85fr; gap: 48px; align-items: center; }
.hero-badge {
  display: inline-block; background: rgba(255,215,0,.15); color: var(--gold);
  padding: 6px 14px; border-radius: 20px; font-size: 13px; font-weight: 600; margin-bottom: 16px;
}
.hero h1 { font-size: clamp(34px, 5vw, 50px); font-weight: 800; margin-bottom: 18px; }
.hero-lead { font-size: 16px; color: rgba(255,255,255,.82); max-width: 520px; margin-bottom: 28px; }
.hero-cta { display: flex; gap: 12px; flex-wrap: wrap; margin-bottom: 28px; }
.hero-tags { display: flex; gap: 10px; flex-wrap: wrap; }
.hero-tags span {
  font-size: 11px; font-weight: 700; letter-spacing: .08em;
  padding: 5px 12px; border-radius: 4px;
  background: rgba(255,255,255,.08); border: 1px solid rgba(255,255,255,.15);
}
.hero-stats { display: flex; flex-direction: column; gap: 14px; }
.stat-box {
  background: rgba(255,255,255,.08); border: 1px solid rgba(255,255,255,.12);
  border-radius: var(--radius-lg); padding: 22px 24px;
  border-left: 4px solid var(--gold);
}
.stat-box.accent { border-left-color: var(--red); background: rgba(218,37,29,.12); }
.stat-box strong { display: block; font-size: 32px; font-weight: 800; color: var(--gold); }
.stat-box span { font-size: 13px; color: rgba(255,255,255,.7); }

/* Trust bar */
.trust-bar { background: var(--red-soft); border-bottom: 1px solid var(--gray-200); padding: 14px 0; }
.trust-inner { display: flex; justify-content: center; gap: 24px; flex-wrap: wrap; font-size: 13px; font-weight: 600; color: var(--navy); }

/* Sections */
.section { padding: 80px 0; }
.section-alt { background: var(--gray-50); }
.section-head { text-align: center; max-width: 640px; margin: 0 auto 48px; }
.section-head h2 { font-size: clamp(28px, 4vw, 38px); font-weight: 800; color: var(--navy); margin-bottom: 12px; }
.section-head p { color: var(--gray-600); font-size: 16px; }

/* Product grid */
.product-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.product-card {
  background: var(--white); border: 1px solid var(--gray-200);
  border-radius: var(--radius-lg); padding: 28px 24px;
  box-shadow: var(--shadow); transition: all .25s; position: relative;
}
.product-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); border-color: var(--red); }
.product-card.featured { border-top: 3px solid var(--red); }
.card-tag {
  position: absolute; top: 16px; right: 16px;
  background: var(--red); color: #fff; padding: 4px 10px;
  border-radius: 4px; font-size: 11px; font-weight: 700;
}
.product-icon { font-size: 36px; margin-bottom: 16px; }
.product-card h3 { font-size: 17px; font-weight: 700; color: var(--navy); margin-bottom: 8px; }
.product-card p { font-size: 14px; color: var(--gray-600); }

/* Split */
.split { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; align-items: start; }
.split-copy h2 { font-size: clamp(26px, 3.5vw, 34px); color: var(--navy); margin-bottom: 16px; }
.split-copy p { color: var(--gray-600); margin-bottom: 12px; font-size: 15px; }
.check-list { list-style: none; margin: 20px 0 28px; }
.check-list li {
  padding-left: 28px; position: relative; margin-bottom: 10px; font-size: 15px; font-weight: 500;
}
.check-list li::before {
  content: "✓"; position: absolute; left: 0;
  width: 20px; height: 20px; background: var(--red-soft); color: var(--red);
  border-radius: 50%; font-size: 11px; display: grid; place-items: center; font-weight: 700;
}
.info-cards { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.info-card {
  background: var(--white); border: 1px solid var(--gray-200);
  border-radius: var(--radius-lg); padding: 22px; text-align: center; box-shadow: var(--shadow);
}
.info-card strong { display: block; font-size: 22px; font-weight: 800; color: var(--navy); margin-bottom: 4px; }
.info-card span { font-size: 12px; color: var(--gray-600); }
.info-card.highlight { background: var(--red); color: #fff; border-color: var(--red); }
.info-card.highlight strong { color: var(--gold); }
.info-card.highlight span { color: rgba(255,255,255,.85); }

/* Advantages */
.adv-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.adv-card { padding: 24px 0; border-top: 3px solid var(--red); }
.adv-num { font-size: 12px; font-weight: 800; color: var(--gold-dark); letter-spacing: .08em; display: block; margin-bottom: 10px; }
.adv-card h3 { font-size: 16px; color: var(--navy); margin-bottom: 8px; }
.adv-card p { font-size: 14px; color: var(--gray-600); }

/* Stats bar */
.stats-bar { background: var(--navy); color: #fff; padding: 56px 0; }
.stat-row { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; text-align: center; }
.stat-item strong { font-size: 42px; font-weight: 800; color: var(--gold); display: block; }
.stat-item span { font-size: 13px; color: rgba(255,255,255,.7); margin-top: 6px; display: block; }

/* Testimonial */
.testimonial {
  max-width: 720px; margin: 0 auto; text-align: center;
  padding: 32px; background: var(--white); border-radius: var(--radius-lg);
  border: 1px solid var(--gray-200); box-shadow: var(--shadow);
}
.testimonial p { font-size: 18px; font-weight: 500; color: var(--navy); margin-bottom: 16px; line-height: 1.6; }
.testimonial footer { font-size: 14px; color: var(--gray-600); }

/* Model cards */
.model-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.model-card {
  background: var(--white); border: 1px solid var(--gray-200);
  border-radius: var(--radius-lg); padding: 32px 28px;
  box-shadow: var(--shadow); position: relative; display: flex; flex-direction: column;
}
.model-card.featured { border: 2px solid var(--red); }
.model-badge {
  position: absolute; top: -12px; left: 24px;
  background: var(--red); color: #fff; padding: 4px 14px;
  border-radius: 20px; font-size: 12px; font-weight: 700;
}
.model-card h3 { font-size: 19px; margin-bottom: 10px; margin-top: 4px; color: var(--navy); }
.model-card > p { color: var(--gray-600); font-size: 14px; margin-bottom: 16px; }
.model-card ul { list-style: none; margin-bottom: 24px; flex: 1; }
.model-card ul li { padding-left: 20px; position: relative; margin-bottom: 8px; font-size: 14px; color: var(--gray-600); }
.model-card ul li::before { content: "•"; position: absolute; left: 0; color: var(--red); font-weight: 700; }

/* Contact */
.contact-section { background: var(--gray-50); }
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; align-items: start; }
.contact-info h2 { font-size: clamp(28px, 4vw, 36px); color: var(--navy); margin-bottom: 14px; }
.contact-info > p { color: var(--gray-600); margin-bottom: 28px; }
.contact-list { display: flex; flex-direction: column; gap: 20px; }
.contact-item { display: flex; gap: 14px; align-items: flex-start; }
.contact-item > span { font-size: 22px; }
.contact-item strong { display: block; font-size: 12px; text-transform: uppercase; letter-spacing: .06em; color: var(--gray-400); margin-bottom: 4px; }
.contact-item p { font-size: 15px; line-height: 1.5; }
.contact-item a { color: var(--red); font-weight: 600; }
.contact-form {
  background: var(--white); border-radius: var(--radius-lg);
  padding: 32px; border: 1px solid var(--gray-200); box-shadow: var(--shadow-lg);
}
.field { margin-bottom: 16px; }
.field-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.field label { display: block; font-size: 13px; font-weight: 600; margin-bottom: 6px; color: var(--gray-800); }
.field input, .field textarea {
  width: 100%; padding: 12px 14px; border: 1px solid var(--gray-200);
  border-radius: var(--radius); font-size: 15px; font-family: inherit;
  background: var(--gray-50); transition: border .15s; resize: vertical;
}
.field input:focus, .field textarea:focus { outline: none; border-color: var(--red); box-shadow: 0 0 0 3px rgba(218,37,29,.12); }
.form-note { margin-top: 14px; text-align: center; color: #16a34a; font-weight: 600; font-size: 14px; }

/* Footer */
.footer { background: var(--navy); color: rgba(255,255,255,.75); padding: 56px 0 24px; }
.footer-grid { display: grid; grid-template-columns: 1.5fr repeat(3, 1fr); gap: 32px; padding-bottom: 36px; border-bottom: 1px solid rgba(255,255,255,.1); }
.footer .brand-name { font-family: var(--font-display); font-size: 20px; font-weight: 700; color: #fff; display: block; margin-bottom: 12px; }
.footer .brand-name small { font-size: 13px; font-weight: 500; color: rgba(255,255,255,.6); }
.footer-brand p { font-size: 14px; max-width: 280px; }
.footer-col h4 { color: var(--gold); font-size: 12px; font-weight: 700; letter-spacing: .1em; text-transform: uppercase; margin-bottom: 14px; }
.footer-col a, .footer-col span { display: block; font-size: 14px; margin-bottom: 8px; color: rgba(255,255,255,.65); transition: color .15s; }
.footer-col a:hover { color: var(--gold); }
.footer-bottom { display: flex; justify-content: space-between; padding-top: 20px; font-size: 13px; flex-wrap: wrap; gap: 8px; color: rgba(255,255,255,.45); }

.reveal { opacity: 0; transform: translateY(18px); transition: all .55s ease; }
.reveal.in { opacity: 1; transform: none; }

@media (max-width: 960px) {
  .nav-links, .nav-actions .btn-primary { display: none; }
  .nav-links.open {
    display: flex; flex-direction: column; position: absolute;
    top: 100%; left: 16px; right: 16px; background: var(--white);
    padding: 20px; border-radius: var(--radius-lg); gap: 14px;
    box-shadow: var(--shadow-lg); border: 1px solid var(--gray-200);
  }
  .nav-toggle { display: flex; }
  .hero-inner, .split, .contact-grid { grid-template-columns: 1fr; }
  .product-grid, .model-grid { grid-template-columns: 1fr 1fr; }
  .adv-grid, .stat-row { grid-template-columns: 1fr 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .field-row { grid-template-columns: 1fr; }
}
@media (max-width: 520px) {
  .product-grid, .model-grid, .adv-grid, .stat-row, .footer-grid { grid-template-columns: 1fr; }
  .topbar-inner { flex-direction: column; gap: 8px; text-align: center; }
}