:root {
  --bg: #0b0d17;
  --bg-alt: #11142a;
  --card: #161a33;
  --border: #262b4d;
  --text: #e8eaf6;
  --muted: #9aa0c3;
  --accent: #7c5cff;
  --accent-2: #22d3ee;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: "Be Vietnam Pro", system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}
a { color: inherit; text-decoration: none; }
.container { max-width: 1120px; margin: 0 auto; padding: 0 16px; }

/* Nav */
.nav {
  position: sticky; top: 0; z-index: 10;
  background: rgba(11, 13, 23, .75);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.logo { display: flex; align-items: center; gap: 10px; font-weight: 800; font-size: 1.1rem; }
.logo-mark {
  width: 26px; height: 26px; border-radius: 8px;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
}
.links { display: flex; align-items: center; gap: 24px; font-size: .95rem; color: var(--muted); }
.links a:hover { color: var(--text); }
.links .btn { color: #fff; }

/* Buttons */
.btn {
  display: inline-block; padding: 12px 24px; border-radius: 999px;
  background: linear-gradient(135deg, var(--accent), #5b3df5);
  color: #fff; font-weight: 600;
  box-shadow: 0 8px 24px rgba(124, 92, 255, .35);
  transition: transform .2s, box-shadow .2s;
}
.btn:hover { transform: translateY(-2px); box-shadow: 0 12px 32px rgba(124, 92, 255, .5); }
.btn-sm { padding: 8px 18px; font-size: .9rem; }
.btn-lg { padding: 16px 32px; font-size: 1.1rem; }
.btn-ghost { background: transparent; border: 1px solid var(--border); box-shadow: none; }
.btn-ghost:hover { border-color: var(--accent); box-shadow: none; }

/* Hero */
.hero { position: relative; overflow: hidden; padding: 120px 0 100px; text-align: center; }
.glow {
  position: absolute; inset: -40% 0 auto; height: 700px; margin: auto; width: 900px; max-width: 100%;
  background: radial-gradient(closest-side, rgba(124, 92, 255, .35), transparent),
              radial-gradient(closest-side at 70% 60%, rgba(34, 211, 238, .2), transparent);
  filter: blur(40px); pointer-events: none;
}
.hero-inner { position: relative; }
.badge {
  display: inline-block; padding: 6px 14px; border-radius: 999px;
  border: 1px solid var(--border); background: var(--card);
  color: var(--muted); font-size: .85rem; margin-bottom: 24px;
}
h1 { font-size: clamp(2.2rem, 6vw, 4rem); line-height: 1.15; font-weight: 800; letter-spacing: -.02em; max-width: 820px; margin: 0 auto; }
.grad { background: linear-gradient(90deg, var(--accent), var(--accent-2)); -webkit-background-clip: text; background-clip: text; color: transparent; }
.lead { color: var(--muted); font-size: 1.15rem; max-width: 620px; margin: 24px auto 36px; }
.cta { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }
.stats { display: flex; justify-content: center; gap: 56px; margin-top: 72px; flex-wrap: wrap; }
.stats strong { display: block; font-size: 2rem; font-weight: 800; }
.stats span { color: var(--muted); font-size: .9rem; }

/* Sections */
.section { padding: 96px 0; }
.section.alt { background: var(--bg-alt); }
h2 { font-size: clamp(1.8rem, 4vw, 2.5rem); font-weight: 800; text-align: center; letter-spacing: -.01em; }
.sub { color: var(--muted); text-align: center; margin: 12px 0 48px; }

.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 20px; }
.card {
  background: var(--card); border: 1px solid var(--border); border-radius: 18px; padding: 28px;
  transition: transform .25s, border-color .25s;
}
.card:hover { transform: translateY(-6px); border-color: var(--accent); }
.icon { font-size: 1.8rem; margin-bottom: 16px; }
.card h3 { font-size: 1.15rem; margin-bottom: 8px; }
.card p { color: var(--muted); font-size: .95rem; }

.steps { list-style: none; display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 20px; }
.steps li { padding: 28px; border-left: 2px solid var(--accent); background: var(--card); border-radius: 0 16px 16px 0; }
.steps span { color: var(--accent-2); font-weight: 800; font-size: 1.4rem; }
.steps h3 { margin: 8px 0 6px; }
.steps p { color: var(--muted); font-size: .95rem; }

.contact { text-align: center; }

.footer { border-top: 1px solid var(--border); padding: 28px 0; text-align: center; color: var(--muted); font-size: .9rem; }

@media (max-width: 640px) {
  .links a:not(.btn) { display: none; }
  .hero { padding: 80px 0 64px; }
  .stats { gap: 32px; }
  .section { padding: 64px 0; }
}

/* Pricing */
.pricing { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 20px; align-items: stretch; }
.plan {
  position: relative; display: flex; flex-direction: column;
  background: var(--card); border: 1px solid var(--border); border-radius: 20px; padding: 32px 28px;
}
.plan.featured { border-color: var(--accent); box-shadow: 0 20px 50px rgba(124, 92, 255, .25); }
.plan-tag {
  position: absolute; top: -12px; left: 50%; transform: translateX(-50%);
  background: linear-gradient(135deg, var(--accent), var(--accent-2)); color: #fff;
  font-size: .78rem; font-weight: 700; padding: 4px 14px; border-radius: 999px; white-space: nowrap;
}
.plan h3 { font-size: 1.15rem; }
.plan-price { font-size: 2.4rem; font-weight: 800; margin-top: 12px; letter-spacing: -.01em; line-height: 1.2; }
.plan-vnd { color: var(--muted); font-size: .9rem; margin-bottom: 20px; }
.plan ul { list-style: none; margin-bottom: 28px; flex: 1; }
.plan li { padding: 7px 0 7px 26px; position: relative; color: var(--muted); font-size: .95rem; }
.plan li::before { content: "✓"; position: absolute; left: 0; color: var(--accent-2); font-weight: 700; }
.btn-block { display: block; width: 100%; text-align: center; border: 0; cursor: pointer; font: inherit; font-weight: 600; }
.btn-ghost.btn-block { border: 1px solid var(--border); color: var(--text); }
.pay-badges { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; margin-top: 32px; }
.pay-badges span { border: 1px solid var(--border); border-radius: 999px; padding: 6px 14px; color: var(--muted); font-size: .88rem; }

/* Checkout modal */
.modal {
  position: fixed; inset: 0; z-index: 50; display: grid; place-items: center; padding: 16px;
  background: rgba(5, 6, 14, .7); backdrop-filter: blur(6px); overflow-y: auto;
}
.modal[hidden] { display: none; }
.modal-box {
  position: relative; width: 100%; max-width: 440px; background: var(--bg-alt);
  border: 1px solid var(--border); border-radius: 20px; padding: 28px; animation: pop .2s ease-out;
}
@keyframes pop { from { transform: scale(.96); opacity: 0; } }
.modal-close {
  position: absolute; top: 12px; right: 14px; background: none; border: 0; color: var(--muted);
  font-size: 1.6rem; line-height: 1; cursor: pointer;
}
.modal-box h3 { font-size: 1.3rem; margin-bottom: 16px; text-align: center; }
.co-summary {
  display: flex; justify-content: space-between; align-items: center; gap: 12px;
  background: var(--card); border-radius: 12px; padding: 14px 16px; margin-bottom: 18px;
}
#co-form label:not(.method) { display: block; font-size: .88rem; color: var(--muted); margin-bottom: 12px; }
#co-form input:not([type=radio]) {
  display: block; width: 100%; margin-top: 6px; padding: 12px 14px; border-radius: 10px;
  background: var(--card); border: 1px solid var(--border); color: var(--text); font: inherit;
}
#co-form input:focus { outline: 2px solid var(--accent); outline-offset: 0; border-color: transparent; }
.methods { border: 0; margin: 6px 0 4px; }
.methods legend { font-size: .88rem; color: var(--muted); margin-bottom: 8px; }
.method {
  display: flex; gap: 12px; align-items: center; padding: 12px 14px; margin-bottom: 8px;
  border: 1px solid var(--border); border-radius: 12px; cursor: pointer; transition: border-color .2s;
}
.method:has(input:checked) { border-color: var(--accent); background: rgba(124, 92, 255, .08); }
.method:has(input:disabled) { opacity: .45; cursor: not-allowed; }
.method input { accent-color: var(--accent); }
.method small { display: block; color: var(--muted); font-size: .82rem; }
.method em { color: #fbbf24; font-style: normal; }
.co-error { color: #f87171; font-size: .9rem; min-height: 1.4em; margin: 6px 0; }

.qr { background: #fff; border-radius: 16px; padding: 12px; width: 230px; margin: 0 auto 16px; }
.qr svg { display: block; width: 100%; height: auto; }
.bank { display: grid; grid-template-columns: auto 1fr; gap: 8px 14px; font-size: .92rem; background: var(--card); border-radius: 12px; padding: 14px 16px; }
.bank dt { color: var(--muted); }
.bank dd { text-align: right; word-break: break-all; }
.copy { background: none; border: 1px solid var(--border); color: var(--accent-2); border-radius: 6px; padding: 1px 8px; font: inherit; font-size: .75rem; cursor: pointer; margin-left: 4px; }
.waiting { display: flex; align-items: center; justify-content: center; gap: 10px; margin-top: 16px; color: var(--muted); font-size: .92rem; }
.spinner { width: 16px; height: 16px; border: 2px solid var(--border); border-top-color: var(--accent); border-radius: 50%; animation: spin 1s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }
.note { text-align: center; color: var(--muted); font-size: .8rem; margin-top: 8px; }
.done { text-align: center; }
.done p { color: var(--muted); margin-bottom: 22px; }
.done-icon {
  width: 64px; height: 64px; margin: 4px auto 16px; border-radius: 50%; display: grid; place-items: center;
  background: rgba(34, 197, 94, .15); color: #22c55e; font-size: 2rem; font-weight: 800;
}
.done-icon.fail { background: rgba(248, 113, 113, .15); color: #f87171; }
.done-icon.wait { background: rgba(251, 191, 36, .15); color: #fbbf24; }