html {
    scroll-behavior: smooth;
  }
  
  section {
    scroll-margin-top: 80px;
  }
  
  :root {
    --bluetiful: #0083CC;
    --blueOldGunGeonRed: #045DE9;
    --blueSpiroDiscoBall: #09C6F9;
    --gray100: #f0f0f0;
    --gray300: #D1D1D1;
    --gray500: #9D9CA5;
    --gray800: #3E3E3E;
    --gray900: #393939;
  }
  
  body {
    font-family: sans-serif;
    background-color: var(--gray100);
    color: #333;
  }
  
  .section-bluetiful {
    background-color: var(--bluetiful);
    color: white;
  }
  
  .section-blueOldGunGeonRed {
    background-color: var(--blueOldGunGeonRed);
    color: white;
  }
  
  .section-gradient {
    background: linear-gradient(to right, var(--blueOldGunGeonRed), var(--blueSpiroDiscoBall));
    color: white;
  }
  
  .btn {
    background-color: var(--bluetiful);
    color: white;
    padding: 0.75rem 1.25rem;
    border: none;
    border-radius: 0.375rem;
    cursor: pointer;
    transition: background-color 0.3s;
  }
  
  .btn:hover {
    background-color: #006bb0;
  }
  
  .titre {
    color: var(--bluetiful);
    font-size: 2rem;
    margin-bottom: 1rem;
  }
  
  header {
    background-color: var(--gray100);
    padding: 1rem;
    color: var(--gray900);
  }
  
  .nav-link {
    color: var(--gray900);
    transition: color 0.2s ease;
  }
  
  .nav-link:hover {
    color: var(--bluetiful);
  }