html, body {
  margin: 0;
  padding: 0;
  height: 100%;
}

body {
  min-height: 100vh;
  background:
    linear-gradient(rgba(0,0,0,0.18), rgba(0,0,0,0.58)),
    url("background.jpg") center center / cover no-repeat;
  font-family: Arial, "Microsoft YaHei", sans-serif;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #ffd700;
  text-align: center;
}

.box {
  background: rgba(0,0,0,0.25);
  padding: 30px 36px;
  border-radius: 20px;
  max-width: 96vw;
  box-sizing: border-box;
}

.title {
  color: white;
  font-size: clamp(32px, 6vw, 72px);
  font-weight: 800;
  line-height: 1.18;
  white-space: nowrap;
  text-shadow: 0 5px 15px black;
}

#timer {
  margin-top: 30px;
  font-size: clamp(42px, 8vw, 96px);
  font-weight: 900;
  white-space: nowrap;
  text-shadow: 0 6px 18px black;
}

#last10 {
  display: none;
  margin-top: 20px;
  font-size: clamp(160px, 34vw, 360px);
  font-weight: 900;
  line-height: 1;
  text-shadow: 0 10px 30px black;
  animation: pulse 1s infinite;
}

#endText {
  display: none;
  margin-top: 25px;
  font-size: clamp(60px, 12vw, 140px);
  font-weight: 900;
  line-height: 1.25;
  text-shadow: 0 10px 30px black;
}

@keyframes pulse {
  0% { transform: scale(1); }
  50% { transform: scale(1.08); }
  100% { transform: scale(1); }
}

@media (max-width: 600px) {
  .box {
    padding: 22px 16px;
  }
  .title {
    font-size: clamp(26px, 7.5vw, 42px);
  }
  #timer {
    font-size: clamp(34px, 8.5vw, 52px);
  }
}