/* Reset */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Inter', sans-serif;
}

body {
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  color: white;
  background: #000;
  position: relative;
  animation: fadeIn 1.2s ease forwards;
}

/* Subtle animated spotlights */
body::before {
  content: "";
  position: absolute;
  width: 200%;
  height: 200%;
  background:
    radial-gradient(circle at 20% 30%, rgba(255,255,255,0.12), transparent 45%),
    radial-gradient(circle at 80% 70%, rgba(255,255,255,0.10), transparent 50%),
    radial-gradient(circle at 50% 90%, rgba(255,255,255,0.06), transparent 60%);
  animation: moveLights 30s ease-in-out infinite alternate;
  z-index: -1;
}

/* Container */
.container {
  text-align: center;
  max-width: 600px;
  padding: 20px;
}

/* Title */
h1 {
  font-size: 3.5rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  letter-spacing: 1px;
}

/* Subtitle */
.subtitle {
  font-size: 1.2rem;
  opacity: 0.7;
  margin-bottom: 2rem;
}

/* Topics */
.topics {
  list-style: none;
  display: flex;
  justify-content: center;
  gap: 15px;
  flex-wrap: wrap;
  margin-bottom: 2rem;
}

.topics li {
  padding: 6px 14px;
  border-radius: 20px;
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.08);
  font-size: 0.9rem;
  transition: all 0.2s ease;
}

.topics li:hover {
  background: rgba(37,99,235,0.15);
  border-color: rgba(37,99,235,0.4);
  color: #93c5fd; /* bleu clair premium */
  transform: translateY(-2px);
}

/* Button */
.button {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 12px 28px;
  border-radius: 30px;
  background: white;
  color: black;
  font-weight: 600;
  text-decoration: none;
  transition: all 0.25s ease;
}

.button:hover {
  background: #0d6efd;          /* bleu propre */
  color: white;
  transform: translateY(-2px);
  box-shadow: 0 0 25px rgba(13,110,253,0.35);
}

/* Animations */
@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes moveLights {
  from { transform: translate(0%, 0%); }
  to { transform: translate(-8%, -4%); }
}