:root{
  --bg: #070A12;
  --panel: rgba(255,255,255,.06);
  --panel2: rgba(255,255,255,.08);
  --text: rgba(255,255,255,.92);
  --muted: rgba(255,255,255,.68);
  --line: rgba(255,255,255,.10);

  --brandA: rgba(110,231,255,.16);   /* cyan glow */
  --brandB: rgba(139,92,246,.16);    /* purple glow */
  --gold:   rgba(246,211,101,.12);   /* gold glow */

  --shadow: 0 18px 50px rgba(0,0,0,.45);
  --radius: 18px;
}

*{box-sizing:border-box}
html,body{height:100%}
body{
  margin:0;
  font-family: "Be Vietnam Pro", system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  /* ✅ NỀN CHÍNH CHỈ TỐI – KHÔNG DÙNG RADIAL Ở BODY ĐỂ TRÁNH “LỆCH” */
  background: var(--bg);
  color: var(--text);
  overflow-x:hidden;
}

a{color:inherit; text-decoration:none}
.wrap{max-width:1100px; margin:0 auto; padding:0 20px}

/* =========================
   TOPBAR
========================= */
.topbar{
  position:sticky; top:0; z-index:50;
  background: rgba(7,10,18,.72);
  backdrop-filter: blur(12px);
  border-bottom:1px solid var(--line);
}
.topbar-inner{
  display:flex; align-items:center; gap:16px;
  padding:14px 0;
}
.brand{display:flex; align-items:center; gap:10px; font-weight:800}
.brand-mark{
  width:34px; height:34px; display:grid; place-items:center;
  border-radius:12px;
  background: linear-gradient(135deg, rgba(110,231,255,.20), rgba(139,92,246,.22));
  border:1px solid rgba(255,255,255,.12);
}
.brand-text{letter-spacing:.2px}

.nav{display:flex; gap:14px; margin-left:auto}
.nav a{opacity:.85; font-weight:600; font-size:14px}
.nav a:hover{opacity:1}

.btn{
  display:inline-flex; align-items:center; justify-content:center;
  padding:12px 16px; border-radius:14px;
  border:1px solid rgba(255,255,255,.14);
  background: rgba(255,255,255,.06);
  color:var(--text);
  font-weight:800;
  cursor:pointer;
  transition: transform .12s ease, background .12s ease, border-color .12s ease;
}
.btn:hover{transform: translateY(-1px); background: rgba(255,255,255,.08)}
.btn.small{padding:10px 12px; font-size:13px}
.btn.primary{
  background: linear-gradient(135deg, rgba(110,231,255,.20), rgba(139,92,246,.22));
  border-color: rgba(110,231,255,.35);
}
.btn.ghost{
  background: transparent;
  border-color: rgba(255,255,255,.18);
}

.burger{
  display:none;
  background:transparent; border:0; padding:10px; cursor:pointer;
}
.burger span{display:block; width:22px; height:2px; background:rgba(255,255,255,.86); margin:5px 0; border-radius:2px}

.mobile-nav{
  display:none;
  border-top:1px solid var(--line);
  padding:12px 20px 16px;
}
.mobile-nav a{display:block; padding:10px 0; opacity:.9; font-weight:700}
.mobile-nav a:hover{opacity:1}
.mobile-nav.show{display:block}

/* =========================
   ✅ SECTION BACKGROUND ENGINE
   Mỗi section tự có “glow” riêng -> không bị lệch khi scroll
========================= */
.hero, .section{
  position:relative;
  overflow:hidden;
}

/* layer nền cho section */
.hero::before,
.section::before{
  content:"";
  position:absolute;
  inset:-140px 0;              /* phủ rộng để glow không bị cắt */
  pointer-events:none;
  z-index:0;
  opacity:1;
  background:
    radial-gradient(900px 520px at 18% 18%, var(--brandA), transparent 60%),
    radial-gradient(820px 520px at 82% 12%, var(--brandB), transparent 62%),
    radial-gradient(920px 620px at 70% 80%, rgba(246,211,101,.08), transparent 62%);
  transform: translateZ(0);     /* giảm jitter */
}

/* section-dark: nền khác một chút (đậm hơn) */
.section-dark::before{
  background:
    radial-gradient(850px 520px at 20% 30%, rgba(255,255,255,.06), transparent 62%),
    radial-gradient(820px 520px at 78% 20%, rgba(110,231,255,.12), transparent 62%),
    radial-gradient(900px 620px at 60% 85%, rgba(139,92,246,.10), transparent 64%);
  opacity:.95;
}

/* đảm bảo nội dung nằm trên lớp nền */
.hero > .wrap,
.section > .wrap{
  position:relative;
  z-index:1;
}

/* =========================
   HERO
========================= */
.hero{padding:48px 0 24px}
.hero-grid{display:grid; grid-template-columns: 1.15fr .85fr; gap:22px; align-items:center}
.pill{
  display:inline-flex; align-items:center; gap:8px;
  padding:8px 12px; border-radius:999px;
  border:1px solid rgba(255,255,255,.14);
  background: rgba(255,255,255,.06);
  font-weight:800;
  margin-bottom:14px;
}
h1{font-size:44px; line-height:1.05; margin:0 0 12px}
.lead{font-size:16px; color:var(--muted); line-height:1.7; margin:0 0 18px}
.cta-row{display:flex; gap:12px; flex-wrap:wrap; margin-bottom:16px}

.badges{display:flex; gap:10px; flex-wrap:wrap}
.badge{
  font-size:12px; font-weight:800; color:rgba(255,255,255,.82);
  border:1px solid rgba(255,255,255,.12);
  background: rgba(255,255,255,.06);
  padding:8px 10px; border-radius:999px;
}

.hero-card{
  border-radius: var(--radius);
  border:1px solid rgba(255,255,255,.12);
  background: rgba(255,255,255,.05);
  box-shadow: var(--shadow);
  overflow:hidden;
}
.hero-card-head{
  display:flex; align-items:center; gap:8px;
  padding:12px 14px;
  border-bottom:1px solid rgba(255,255,255,.10);
  color: rgba(255,255,255,.72);
  font-weight:800; font-size:12px;
}
.dot{width:10px; height:10px; border-radius:50%; background:rgba(255,255,255,.18)}
.hero-card-body{padding:14px}
.img{width:100%; height:auto; border-radius:14px; border:1px solid rgba(255,255,255,.12)}
.shadow{box-shadow: var(--shadow)}
.mini{font-size:12px; color:var(--muted); line-height:1.55}
.center{text-align:center}

/* =========================
   SECTIONS / CARDS
========================= */
.section{padding:56px 0}
.section-dark{
  border-top:1px solid rgba(255,255,255,.08);
  border-bottom:1px solid rgba(255,255,255,.08);
  /* nền tối nhẹ để tách section */
  background: linear-gradient(180deg, rgba(255,255,255,.03), transparent 60%);
}

.section-title{margin-bottom:18px}
.section-title.left{text-align:left}
.section-title h2{margin:0 0 8px; font-size:30px}
.section-title p{margin:0; color:var(--muted); line-height:1.6}

.grid3{display:grid; grid-template-columns: repeat(3, 1fr); gap:14px; margin-top:14px}
.card{
  border-radius: var(--radius);
  border:1px solid rgba(255,255,255,.12);
  background: rgba(255,255,255,.05);
  padding:16px;
}
.card .icon{font-size:22px; margin-bottom:10px}
.card h3{margin:0 0 8px; font-size:18px}
.card p{margin:0; color:var(--muted); line-height:1.6}
.card ul{margin:10px 0 0; padding-left:18px; color:var(--muted); line-height:1.65}
.card li{margin:6px 0}

.callout{
  display:flex; align-items:center; justify-content:space-between; gap:14px;
  margin-top:16px;
  border-radius: var(--radius);
  border:1px solid rgba(110,231,255,.20);
  background: linear-gradient(135deg, rgba(110,231,255,.10), rgba(139,92,246,.10));
  padding:16px;
}
.callout h3{margin:0 0 6px}
.callout p{margin:0; color:var(--muted); line-height:1.6}
.callout-right{display:flex; gap:8px; flex-wrap:wrap; justify-content:flex-end}
.tag{
  display:inline-flex; align-items:center; justify-content:center;
  padding:7px 10px; border-radius:999px;
  background: rgba(255,255,255,.06);
  border:1px solid rgba(255,255,255,.12);
  font-weight:900; font-size:12px;
}

/* GUIDE */
.guide-grid{display:grid; grid-template-columns: 1fr 1fr; gap:16px; align-items:start}
.step{
  display:flex; gap:12px;
  padding:14px;
  border-radius: var(--radius);
  border:1px solid rgba(255,255,255,.10);
  background: rgba(255,255,255,.04);
  margin-bottom:10px
}
.num{
  width:34px; height:34px; border-radius:12px;
  display:grid; place-items:center;
  font-weight:900;
  background: rgba(255,255,255,.06);
  border:1px solid rgba(255,255,255,.12);
}
.step h3{margin:0 0 6px; font-size:16px}
.step p{margin:0; color:var(--muted); line-height:1.6}
.guide-img .mini{margin-top:10px}

.note{
  margin-top:14px;
  padding:12px 14px;
  border-radius: var(--radius);
  border:1px solid rgba(255,255,255,.10);
  background: rgba(255,255,255,.04);
  color: rgba(255,255,255,.80);
  font-weight:700;
}

/* PRICING */
.pricing-grid{display:grid; grid-template-columns: repeat(3, 1fr); gap:14px; margin-top:14px}
.plan{
  border-radius: var(--radius);
  border:1px solid rgba(255,255,255,.12);
  background: rgba(255,255,255,.05);
  padding:16px;
  position:relative;
}
.plan .name{display:flex; align-items:center; justify-content:space-between; gap:10px; margin-bottom:10px; font-weight:900}
.plan .price{font-size:28px; font-weight:900; margin-bottom:10px}
.plan .price span{font-size:13px; color:var(--muted); font-weight:900}
.plan .list{margin:0; padding-left:18px; color:var(--muted); line-height:1.65}
.plan.featured{
  border-color: rgba(110,231,255,.35);
  background: linear-gradient(135deg, rgba(110,231,255,.10), rgba(139,92,246,.10));
}
.plan.lifetime{
  border-color: rgba(246,211,101,.40);
  background: linear-gradient(135deg, rgba(246,211,101,.12), rgba(255,140,0,.08));
}

.cta-wide{
  margin-top:16px;
  display:flex; align-items:center; justify-content:space-between; gap:14px;
  border-radius: var(--radius);
  border:1px solid rgba(255,255,255,.12);
  background: rgba(255,255,255,.04);
  padding:16px;
}
.cta-wide h3{margin:0 0 6px}
.cta-wide p{margin:0; color:var(--muted); line-height:1.6}

/* DONATE */
.donate-grid{display:grid; grid-template-columns: 1fr .9fr; gap:16px; align-items:center}
.donate-card{
  border-radius: var(--radius);
  border:1px solid rgba(255,255,255,.12);
  background: rgba(255,255,255,.05);
  padding:16px;
  text-align:center;
}
.qr{
  width:min(320px, 100%);
  border-radius:16px;
  border:1px solid rgba(255,255,255,.12);
  background:white;
  padding:12px;
}

/* FOOTER */
.footer{
  padding:26px 0;
  border-top:1px solid rgba(255,255,255,.10);
  background: rgba(0,0,0,.18);
}
.footer-inner{display:flex; align-items:center; justify-content:space-between; gap:12px}
.sep{margin:0 8px; opacity:.7}

code{
  background: rgba(255,255,255,.08);
  border:1px solid rgba(255,255,255,.10);
  padding:2px 6px;
  border-radius:8px;
  font-weight:800;
}

/* =========================
   Responsive
========================= */
@media (max-width: 920px){
  .hero-grid{grid-template-columns:1fr;}
  h1{font-size:38px}
  .grid3{grid-template-columns:1fr}
  .pricing-grid{grid-template-columns:1fr}
  .guide-grid{grid-template-columns:1fr}
  .donate-grid{grid-template-columns:1fr}

  .nav{display:none}
  .burger{display:inline-block; margin-left:auto}
  #btnTelegramTop{display:none}
}