* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html, body {
  height: 100%;
}

body {
  position: relative;
  background: #2a1a12;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  padding: 12px 0;
  font-family: Arial, Helvetica, sans-serif;
  overflow-x: hidden;
}

/* Blurred, theme-matched backdrop filling the whole viewport */
body::before {
  content: "";
  position: fixed;
  inset: -40px; /* bleed out so blurred edges never show a gap */
  background: url("assets/bg.png") center center / cover no-repeat;
  filter: blur(28px) brightness(0.7) saturate(1.1);
  transform: scale(1.15);
  z-index: -2;
}

/* Subtle dark vignette so the card pops off the backdrop */
body::after {
  content: "";
  position: fixed;
  inset: 0;
  background: radial-gradient(
    ellipse at center,
    rgba(0, 0, 0, 0) 40%,
    rgba(0, 0, 0, 0.45) 100%
  );
  z-index: -1;
}

/* The design canvas — locked to the reference aspect ratio */
.stage {
  position: relative;
  width: 100%;
  max-width: 460px;
  max-height: calc(100vh - 24px);
  aspect-ratio: 750 / 1334;
  overflow: hidden;
  border-radius: 8px;
  box-shadow: 0 8px 40px rgba(0, 0, 0, 0.55);
}

/* Full background scene */
.bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center top;
  display: block;
}

/* Generic overlay: horizontally centered, positioned by top % */
.ov {
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  display: block;
  height: auto;
}

/* OKVND logo */
.logo {
  top: 2.2%;
  width: 35%;
}

/* Nạp 100K tặng ngay 88K */
.promo {
  top: 9.2%;
  width: 88%;
}

/* Đăng ký nhận thưởng ... 8888K */
.b-reg {
  top: 43.5%;
  width: 88%;
}

/* Mời bạn bè ... không giới hạn */
.b-invite {
  top: 61.8%;
  width: 88%;
}

/* Đặc biệt ngày 12 và 28 ... 8000 nghìn tỷ đồng */
.b-special {
  top: 72.5%;
  width: 88%;
}

/* Download button */
.download {
  top: 89.5%;
  width: 56%;
}

.download img {
  width: 100%;
  height: auto;
  display: block;
  transition: transform 0.15s ease;
}

.download:hover img {
  transform: scale(1.04);
}

.download:active img {
  transform: scale(0.98);
}