:root {
  --primary-color: #1E90FF;
  --text-color: #fff;
  --card-bg: rgba(255,255,255,0.12);
  --overlay-bg: rgba(0, 0, 0, 0.55);
  --border-radius: 20px;
  --transition: all 0.3s ease;
}

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

body {
  font-family: 'Inter', Arial, sans-serif;
  background: url('snow.png') center/cover no-repeat fixed;
  min-height: 100vh;
  position: relative;
  overflow-x: hidden;
}

/* Снежинки */
.snowflake {
  position: fixed;
  top: -10px;
  background-color: white;
  border-radius: 50%;
  pointer-events: none;
  opacity: 0.8;
  z-index: 1;
  animation-name: fall;
  animation-timing-function: linear;
  animation-iteration-count: infinite;
}

@keyframes fall {
  0% {
    transform: translateY(0) rotate(0deg);
    opacity: 0.8;
  }
  100% {
    transform: translateY(100vh) rotate(360deg);
    opacity: 0;
  }
}

.overlay {
  position: fixed;
  z-index: 2;
  top: 0;
  left: 0;
  width: 100%;
  height: 100vh;
  background: var(--overlay-bg);
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 20px;
}

.card {
  background: var(--card-bg);
  backdrop-filter: blur(10px);
  border-radius: var(--border-radius);
  padding: 40px 30px;
  max-width: 450px;
  width: 100%;
  text-align: center;
  color: var(--text-color);
  box-shadow: 0 0 40px rgba(0,0,0,0.4);
  animation: fadeIn 1.2s ease;
}

@keyframes fadeIn {
  0% {opacity:0; transform: translateY(20px);} 
  100% {opacity:1; transform: translateY(0);} 
}

h1 {
  font-size: 28px;
  margin-bottom: 25px;
  line-height: 1.3;
}

.btn {
  display: block;
  width: 100%;
  max-width: 300px;
  padding: 14px;
  margin: 12px auto;
  background: var(--primary-color);
  border: none;
  border-radius: 10px;
  color: var(--text-color);
  text-decoration: none;
  font-size: 18px;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
}

.btn:hover { 
  opacity: 0.85; 
  transform: translateY(-2px);
}

footer {
  position: fixed;
  bottom: 10px;
  width: 100%;
  text-align: center;
  color: rgba(255,255,255,0.7);
  font-size: 14px;
  z-index: 10;
}

/* Адаптивность */
@media (max-width: 480px) {
  .card {
    padding: 30px 20px;
  }
  
  h1 {
    font-size: 24px;
  }
  
  .btn {
    font-size: 16px;
    padding: 12px;
  }
}