/* ============================================================
   VIA — Chuyên Giá Trị
   Vanilla CSS. Palette: navy + green gradient (từ infographic)
   ============================================================ */

:root {
  --navy-900: #0d2044;
  --navy-800: #123061;
  --navy-700: #1b3f7a;
  --green-600: #1f9d47;
  --green-500: #2eb84f;
  --green-400: #57cc6c;
  --ink: #16233b;
  --muted: #5b6b82;
  --bg: #ffffff;
  --bg-soft: #f3f7fa;
  --line: #e3ebf2;
  --white: #ffffff;

  --grad-brand: linear-gradient(135deg, var(--navy-800) 0%, var(--green-600) 100%);
  --grad-green: linear-gradient(135deg, var(--green-600), var(--green-400));

  --shadow-sm: 0 2px 8px rgba(13, 32, 68, 0.08);
  --shadow-md: 0 12px 32px rgba(13, 32, 68, 0.14);
  --radius: 16px;
  --maxw: 1120px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: "Montserrat", system-ui, -apple-system, "Segoe UI", sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }

.container {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px;
}

a { text-decoration: none; color: inherit; }

/* -------- Buttons -------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-weight: 700;
  font-size: 1rem;
  padding: 14px 28px;
  border-radius: 999px;
  border: 2px solid transparent;
  cursor: pointer;
  transition: transform .15s ease, box-shadow .2s ease, background .2s ease;
  font-family: inherit;
}
.btn:active { transform: translateY(1px); }
.btn-primary {
  background: var(--grad-green);
  color: var(--white);
  box-shadow: 0 8px 20px rgba(31, 157, 71, 0.35);
}
.btn-primary:hover { box-shadow: 0 12px 28px rgba(31, 157, 71, 0.45); transform: translateY(-2px); }
.btn-ghost { color: var(--white); border-color: rgba(255,255,255,.5); }
.btn-ghost:hover { background: rgba(255,255,255,.12); }
.btn-block { width: 100%; }

/* -------- Header -------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(13, 32, 68, 0.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(255,255,255,.08);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}
.brand { display: flex; flex-direction: column; line-height: 1; }
.brand-wordmark {
  font-weight: 900;
  font-size: 1.55rem;
  letter-spacing: -.5px;
  color: var(--white);
  background: linear-gradient(90deg, #ffffff 40%, var(--green-400));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.brand-tagline {
  font-size: .62rem;
  letter-spacing: 2.5px;
  color: var(--green-400);
  font-weight: 700;
  margin-top: 4px;
  text-transform: uppercase;
}
.nav { display: flex; align-items: center; gap: 28px; }
.nav a { color: rgba(255,255,255,.82); font-weight: 600; font-size: .95rem; transition: color .2s; }
.nav a:hover { color: var(--white); }
.nav .nav-cta {
  background: var(--grad-green);
  color: var(--white);
  padding: 9px 20px;
  border-radius: 999px;
}
.nav .nav-cta:hover { color: var(--white); }

.header-right { display: flex; align-items: center; gap: 16px; }

.lang-switch {
  display: inline-flex;
  background: rgba(255,255,255,.08);
  border: 1px solid rgba(255,255,255,.15);
  border-radius: 999px;
  padding: 3px;
}
.lang-switch button {
  background: none;
  border: 0;
  color: rgba(255,255,255,.7);
  font-family: inherit;
  font-weight: 700;
  font-size: .8rem;
  padding: 6px 12px;
  border-radius: 999px;
  cursor: pointer;
  transition: background .2s, color .2s;
  white-space: nowrap;
}
.lang-switch button:hover { color: var(--white); }
.lang-switch button.active {
  background: var(--grad-green);
  color: var(--white);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: 0;
  cursor: pointer;
  padding: 6px;
}
.nav-toggle span {
  width: 26px; height: 3px; background: var(--white); border-radius: 3px;
  transition: transform .25s ease, opacity .25s ease;
}

/* -------- Hero -------- */
.hero {
  position: relative;
  color: var(--white);
  overflow: hidden;
  background: var(--navy-900);
}
.hero-bg {
  position: absolute; inset: 0;
  background:
    radial-gradient(900px 500px at 85% -10%, rgba(46,184,79,.35), transparent 60%),
    radial-gradient(700px 500px at 0% 110%, rgba(27,63,122,.6), transparent 55%),
    var(--grad-brand);
}
.hero-inner {
  position: relative;
  display: grid;
  grid-template-columns: 1.15fr .85fr;
  gap: 48px;
  align-items: center;
  padding: 84px 24px 96px;
}
.eyebrow {
  text-transform: uppercase;
  letter-spacing: 3px;
  font-weight: 700;
  font-size: .8rem;
  color: var(--green-400);
  margin: 0 0 12px;
}
.hero h1 {
  font-size: clamp(2.4rem, 5.5vw, 4rem);
  line-height: 1.05;
  font-weight: 900;
  margin: 0 0 20px;
}
.hero h1 .hl {
  background: linear-gradient(90deg, var(--green-400), #a8e6b4);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.lead { font-size: 1.12rem; color: rgba(255,255,255,.85); max-width: 30em; margin: 0 0 32px; }
.lead strong { color: var(--green-400); }
.hero-actions { display: flex; flex-wrap: wrap; gap: 14px; margin-bottom: 44px; }
.hero-stats {
  list-style: none; margin: 0; padding: 0;
  display: flex; gap: 36px; flex-wrap: wrap;
}
.hero-stats li { display: flex; flex-direction: column; }
.hero-stats .num { font-size: 2.2rem; font-weight: 900; color: var(--green-400); line-height: 1; }
.hero-stats .cap { font-size: .82rem; color: rgba(255,255,255,.7); margin-top: 6px; }

/* Hero card / charger illustration (pure CSS) */
.hero-card {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}
.charger {
  position: relative;
  width: 190px;
  height: 300px;
  background: linear-gradient(160deg, #1b2f52, #0e1d3b);
  border-radius: 28px;
  box-shadow: var(--shadow-md), inset 0 1px 0 rgba(255,255,255,.06);
  display: flex;
  flex-direction: column;
  align-items: center;
  padding-top: 26px;
  border: 1px solid rgba(255,255,255,.08);
}
.charger-head {
  width: 60%; height: 8px; border-radius: 999px;
  background: rgba(255,255,255,.15);
}
.charger-body {
  margin-top: 34px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
}
.charger-logo { font-size: 2.6rem; font-weight: 900; color: var(--white); letter-spacing: -1px; }
.charger-bolt {
  font-size: 1.8rem;
  filter: drop-shadow(0 0 10px rgba(87,204,108,.8));
  animation: pulse 2.2s ease-in-out infinite;
}
.charger-cable {
  position: absolute;
  bottom: -34px; left: 50%;
  width: 10px; height: 60px;
  background: rgba(255,255,255,.25);
  border-radius: 999px;
  transform: translateX(-50%);
}
.hero-badge {
  position: absolute;
  bottom: 4px; right: -8px;
  background: var(--white);
  color: var(--navy-800);
  font-weight: 700;
  font-size: .82rem;
  padding: 10px 16px;
  border-radius: 12px;
  box-shadow: var(--shadow-md);
}
@keyframes pulse { 0%,100%{opacity:1;transform:scale(1);} 50%{opacity:.55;transform:scale(1.12);} }

/* -------- Sections -------- */
.section { padding: 88px 0; }
.section-title {
  font-size: clamp(1.8rem, 3.5vw, 2.6rem);
  font-weight: 900;
  text-align: center;
  margin: 0 0 14px;
}
.section-title.light { color: var(--white); }
.section-sub {
  text-align: center;
  color: var(--muted);
  max-width: 42em;
  margin: 0 auto 48px;
  font-size: 1.05rem;
}
.hl-green {
  background: var(--grad-green);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

/* -------- Features -------- */
.features { background: var(--bg-soft); }
.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 26px;
}
.feature-card {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 34px 28px;
  box-shadow: var(--shadow-sm);
  transition: transform .2s ease, box-shadow .2s ease;
}
.feature-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-md); }
.feature-icon {
  width: 58px; height: 58px;
  display: grid; place-items: center;
  font-size: 1.7rem;
  border-radius: 14px;
  background: var(--grad-green);
  margin-bottom: 18px;
}
.feature-card h3 { margin: 0 0 10px; font-size: 1.2rem; }
.feature-card p { margin: 0; color: var(--muted); }

/* -------- Benefits -------- */
.benefits { background: var(--grad-brand); }
.benefit-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
}
.benefit-card {
  position: relative;
  background: rgba(255,255,255,.06);
  border: 1px solid rgba(255,255,255,.14);
  border-radius: var(--radius);
  padding: 40px 34px 34px;
  color: var(--white);
  overflow: hidden;
}
.benefit-card.highlight {
  background: rgba(46,184,79,.14);
  border-color: rgba(87,204,108,.5);
}
.benefit-no {
  position: absolute;
  top: -14px; right: 18px;
  font-size: 6rem;
  font-weight: 900;
  color: rgba(255,255,255,.09);
  line-height: 1;
}
.benefit-card h3 { margin: 0 0 12px; font-size: 1.4rem; color: var(--green-400); }
.benefit-card p { margin: 0 0 10px; color: rgba(255,255,255,.85); }
.benefit-card .fineprint { font-size: .78rem; color: rgba(255,255,255,.55); }

/* -------- Profit -------- */
.profit-inner {
  display: grid;
  grid-template-columns: 1fr .8fr;
  gap: 56px;
  align-items: center;
}
.profit .section-title, .profit .section-sub { text-align: left; margin-left: 0; }
.flow {
  display: flex;
  align-items: center;
  gap: 14px;
  flex-wrap: wrap;
  margin-top: 28px;
}
.flow-step {
  background: var(--bg-soft);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 14px 18px;
  display: flex;
  flex-direction: column;
  font-weight: 700;
  font-size: .95rem;
  text-align: center;
}
.flow-step small { font-weight: 500; color: var(--muted); font-size: .75rem; }
.flow-step.accent { background: var(--grad-green); color: var(--white); border-color: transparent; }
.flow-arrow { color: var(--green-600); font-weight: 900; font-size: 1.3rem; }

.chart {
  background: var(--bg-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 32px;
  box-shadow: var(--shadow-sm);
}
.chart-bars {
  display: flex;
  align-items: flex-end;
  justify-content: center;
  gap: 48px;
  height: 260px;
}
.bar-group { display: flex; flex-direction: column; align-items: center; height: 100%; justify-content: flex-end; }
.bar {
  width: 84px;
  border-radius: 12px 12px 0 0;
  position: relative;
  height: 0;
  transition: height 1s cubic-bezier(.2,.8,.2,1);
  display: flex;
  align-items: flex-start;
  justify-content: center;
}
.bar-via { background: var(--grad-green); box-shadow: 0 8px 20px rgba(31,157,71,.35); }
.bar-market { background: linear-gradient(180deg, #9fb0c4, #c3ccd8); }
.bar-label {
  position: absolute;
  top: -30px;
  font-weight: 900;
  font-size: 1.25rem;
  color: var(--ink);
}
.bar-name { margin-top: 12px; font-weight: 600; color: var(--muted); font-size: .9rem; }
.chart-note { text-align: center; color: var(--muted); font-size: .82rem; margin: 18px 0 0; }

/* -------- Why -------- */
.why { background: var(--bg-soft); }
.why-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 26px;
}
.why-card {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 34px 28px;
  text-align: center;
  box-shadow: var(--shadow-sm);
  transition: transform .2s ease, box-shadow .2s ease;
}
.why-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-md); }
.why-icon {
  width: 66px; height: 66px;
  margin: 0 auto 18px;
  display: grid; place-items: center;
  font-size: 1.9rem;
  border-radius: 50%;
  background: var(--grad-brand);
}
.why-card h3 { margin: 0 0 10px; font-size: 1.2rem; }
.why-card p { margin: 0; color: var(--muted); }

/* -------- Register -------- */
.register { background: var(--grad-brand); }
.register-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 56px;
  align-items: center;
}
.register-copy h2 { color: var(--white); font-size: clamp(1.8rem, 3.4vw, 2.5rem); font-weight: 900; margin: 0 0 16px; }
.register-copy p { color: rgba(255,255,255,.82); font-size: 1.1rem; margin: 0; }
.register-form {
  background: var(--white);
  border-radius: var(--radius);
  padding: 36px;
  box-shadow: var(--shadow-md);
}
.field { margin-bottom: 20px; }
.field label { display: block; font-weight: 700; margin-bottom: 8px; font-size: .92rem; }
.field input {
  width: 100%;
  padding: 14px 16px;
  border: 2px solid var(--line);
  border-radius: 12px;
  font-size: 1rem;
  font-family: inherit;
  transition: border-color .2s, box-shadow .2s;
}
.field input:focus {
  outline: none;
  border-color: var(--green-500);
  box-shadow: 0 0 0 4px rgba(46,184,79,.15);
}
.field input.invalid { border-color: #e5484d; box-shadow: 0 0 0 4px rgba(229,72,77,.12); }
.form-msg { margin: 16px 0 0; font-weight: 600; text-align: center; min-height: 1.2em; }
.form-msg.ok { color: var(--green-600); }
.form-msg.err { color: #e5484d; }

/* -------- Footer -------- */
.site-footer { background: var(--navy-900); color: rgba(255,255,255,.7); padding: 52px 0 32px; }
.footer-top {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 40px;
  padding-bottom: 28px;
  margin-bottom: 24px;
  border-bottom: 1px solid rgba(255,255,255,.1);
}
.footer-brand .brand-wordmark { font-size: 1.6rem; }
.footer-about { margin: 12px 0 0; max-width: 32em; font-size: .95rem; }
.footer-about strong { color: var(--green-400); }
.footer-biz h4 { margin: 0 0 12px; color: var(--white); font-size: 1rem; }
.footer-biz ul { list-style: none; margin: 0; padding: 0; }
.footer-biz li { position: relative; padding-left: 20px; margin-bottom: 8px; font-size: .92rem; }
.footer-biz li::before { content: "▸"; position: absolute; left: 0; color: var(--green-400); }
.footer-legal { margin: 0 0 6px; text-align: center; }
.footer-legal a { font-size: .85rem; color: rgba(255,255,255,.7); text-decoration: none; }
.footer-legal a:hover { color: #fff; text-decoration: underline; }
.footer-copy { margin: 0; font-size: .85rem; text-align: center; color: rgba(255,255,255,.55); }

/* -------- Responsive -------- */
@media (max-width: 860px) {
  .nav {
    position: fixed;
    inset: 72px 0 auto 0;
    flex-direction: column;
    background: var(--navy-900);
    padding: 20px 24px 28px;
    gap: 18px;
    border-bottom: 1px solid rgba(255,255,255,.1);
    transform: translateY(-140%);
    transition: transform .3s ease;
  }
  .nav.open { transform: translateY(0); }
  .nav-toggle { display: flex; }
  .nav-toggle.open span:nth-child(1) { transform: translateY(8px) rotate(45deg); }
  .nav-toggle.open span:nth-child(2) { opacity: 0; }
  .nav-toggle.open span:nth-child(3) { transform: translateY(-8px) rotate(-45deg); }

  .hero-inner { grid-template-columns: 1fr; gap: 40px; padding-bottom: 72px; }
  .hero-card { order: -1; }
  .feature-grid, .benefit-grid, .why-grid,
  .profit-inner, .register-inner { grid-template-columns: 1fr; }
  .profit .section-title, .profit .section-sub { text-align: center; }
  .flow { justify-content: center; }
  .section { padding: 64px 0; }
  .footer-top { grid-template-columns: 1fr; gap: 28px; }
  .lang-switch button { padding: 6px 9px; font-size: .72rem; }
}

@media (max-width: 420px) {
  .brand-tagline { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { animation: none !important; transition: none !important; }
}