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

body {
  height: 100vh;
  background: linear-gradient(130deg, #0f0f0f, #1a1a1a, #111) no-repeat;
  background-size: 400% 400%;
  animation: gradientShift 15s ease infinite;
  font-family: 'Segoe UI', sans-serif;
  color: #e0e0e0;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 20px;
  padding-top: 70px;
}

.container {
  text-align: center;
  padding: 40px 30px;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 16px;
  box-shadow: 0 0 25px rgba(0, 255, 255, 0.1);
  backdrop-filter: blur(12px);
  max-width: 500px;
  width: 100%;
}

h1 {
  font-size: 2.2rem;
  margin-bottom: 20px;
  color: #70d6ff;
  text-shadow: 0 0 10px rgba(112, 214, 255, 0.5);
}

p {
  font-size: 1.1rem;
  color: #ccc;
}

@keyframes gradientShift {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

.btn-accueil {
  position: absolute;
  top: 20px;
  left: 50%;
  transform: translateX(-50%);
  background-color: #70d6ff;
  color: white;
  padding: 10px 25px;
  border-radius: 12px;
  text-decoration: none;
  font-weight: bold;
  font-size: 16px;
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
  transition: transform 0.2s, box-shadow 0.2s;
}

.btn-accueil:hover {
  transform: translateX(-50%) translateY(-2px);
  box-shadow: 0 6px 12px rgba(0, 0, 0, 0.3);
}

.container:hover {
  box-shadow: 0 0 40px rgba(0, 255, 255, 0.3);
  transform: scale(1.03);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}