* {
    box-sizing: border-box;
    font-family: 'Orbitron', Arial, sans-serif;
  }
  
  body {
    margin: 0;
    background: black;
    color: white;
    overflow-x: hidden;
  }
  
  /* 🌟 Sterren achtergrond */
  .stars, .twinkling {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: block;
    z-index: -1;
  }
  
  .stars {
    background: url('https://www.transparenttextures.com/patterns/stardust.png');
  }
  
  .twinkling {
    background: transparent;
    animation: moveStars 60s linear infinite;
  }
  
  @keyframes moveStars {
    from { transform: translateY(0); }
    to { transform: translateY(-1000px); }
  }
  
  /* 🚀 Header */
  .header.space {
    text-align: center;
    padding: 40px 20px;
    background: radial-gradient(circle at top, #1b2735, #090a0f);
    border-bottom: 1px solid #1e90ff;
  }
  
  .subtitle {
    color: #7fd7ff;
    letter-spacing: 2px;
  }
  
  /* 🧭 Navigatie */
  .space-nav {
    display: flex;
    justify-content: center;
    gap: 30px;
    padding: 20px;
    background: rgba(10, 15, 30, 0.8);
    backdrop-filter: blur(6px);
  }
  
  .space-nav button {
    padding: 14px 30px;
    font-size: 16px;
    border-radius: 30px;
    border: 1px solid #1e90ff;
    background: transparent;
    color: #7fd7ff;
    cursor: pointer;
    transition: 0.3s;
  }
  
  .space-nav button:hover {
    background: #1e90ff;
    color: black;
    box-shadow: 0 0 15px #1e90ff;
  }
  
  /* 📦 Content */
  .content {
    padding: 40px;
  }
  
  .section {
    display: none;
  }
  
  .section.active {
    display: block;
  }
  
  h2 {
    text-align: center;
    margin-bottom: 30px;
    color: #7fd7ff;
  }
  
  /* 🪐 Cards */
  .card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 30px;
  }
  
  .space-card {
    background: rgba(20, 30, 60, 0.8);
    border: 1px solid #1e90ff;
    border-radius: 20px;
    padding: 25px;
    text-align: center;
    transition: 0.3s;
  }
  
  .space-card:hover {
    transform: translateY(-8px) scale(1.03);
    box-shadow: 0 0 25px #1e90ff;
  }
/* BIG GRID */
.card-grid.big {
    grid-template-columns: repeat(3, 1fr);
  }
  
  .space-card.big {
    height: 140px;
    font-size: 18px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    letter-spacing: 1px;
  }
  
  /* PLAYER */
  .player-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.85);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 999;
  }
  
  .player {
    background: #0a0f1e;
    padding: 20px;
    border-radius: 20px;
    box-shadow: 0 0 40px #1e90ff;
  }
  
  .player iframe {
    width: 800px;
    height: 450px;
    border-radius: 15px;
    border: none;
  }
  
  .player audio {
    width: 600px;
  }
  .back-btn {
    position: absolute;
    left: 20px;
    top: 20px;
    color: #7fd7ff;
    text-decoration: none;
    border: 1px solid #1e90ff;
    padding: 8px 16px;
    border-radius: 20px;
    transition: 0.3s;
  }
  
  .back-btn:hover {
    background: #1e90ff;
    color: black;
    box-shadow: 0 0 15px #1e90ff;
  }