/* 背景和布局 */
html, body {
  margin: 0;
  padding: 0;
  height: 100%;
  background: radial-gradient(circle at center, #0f2027 0%, #203a43 60%, #2c5364 100%);
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  overflow: hidden;
  display: flex;
  justify-content: center;
  align-items: center;
}

/* 主容器 */
.container {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  height: 100vh;
  width: 100vw;
  background: none;
  box-shadow: none;
  backdrop-filter: none;
  padding: 0;
  margin: 0;
}


/* 动画：淡入 */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

/* 标题 */
h1 {
  font-size: 4em;
  color: #ffffff;
  text-shadow: 0 0 15px #00ffe0;
  animation: glow 2s infinite alternate;
}
.title {
  font-size: 4em;
  color: #ffffff;
  text-shadow: 0 0 15px #00ffe0;
  animation: glow 2s infinite alternate;
  margin-bottom: 20px;
  text-align: center;
}

/* 动画：发光 */
@keyframes glow {
  from { text-shadow: 0 0 10px #00ffe0; }
  to { text-shadow: 0 0 30px #00ffe0, 0 0 60px #00ffe0; }
}

/* 按钮 */
.btn {
  padding: 15px 40px;
  font-size: 1.2em;
  border: none;
  background: #6A77E7;
  color: #fff;
  border-radius: 30px;
  cursor: pointer;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  box-shadow: 0 0 10px #6A77E7;
}

.btn:hover {
  transform: scale(1.05);
  box-shadow: 0 0 20px #6A77E7, 0 0 40px #6A77E7;
}

/* 粒子容器 */
.particles {
  position: absolute;
  width: 100%;
  height: 100%;
  top: 0;
  left: 0;
  pointer-events: none;
  overflow: hidden;
  z-index: 0;
}

/* 粒子样式 */
.particle {
  position: absolute;
  background-color: rgba(215, 150, 150,0.3);
  border-radius: 50%;
  animation: float 10s infinite linear;
}

/* 粒子上浮动画 */
@keyframes float {
  0% {
    transform: translateY(100vh) scale(0.5);
    opacity: 0;
  }
  50% {
    opacity: 1;
  }
  100% {
    transform: translateY(-10vh) scale(1);
    opacity: 0;
  }
}

.subtitle {
  color: #ffffffcc;
  font-size: 1.2em;
  margin-bottom: 65px;  /* ✅ 与按钮的间距 */
  text-align: center;
}