@font-face {
  font-family: "Scale";
  src: url("fonts/SCALE-VF-REGULAR.woff"),
       url("fonts/SCALE-VF-REGULAR.woff") format("woff")
       url("fonts/Manrope-Regular.woff");
       
}
<style>

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

    .site-logo {
        margin-bottom: 28px;
    }

    .site-logo img {
        width: 200px;
        max-width: 70%;
        height: auto;
        opacity: 0.9;
    }

    body {
      height: 100vh;
      background: url("img/insung-yoon-LfrJsy3Haf0-unsplash.jpg") center/cover no-repeat;
      display: flex;
      align-items: center;
      justify-content: center;
      color: #ffffff;
      font-family: "Manrope", Arial, sans-serif;
      background-size: 100%;
      background-position: 10% 85%;
    }

    body::before {
      content: "";
      position: absolute;
      inset: 0;
      background: rgba(30, 40, 55, 0.65);
      backdrop-filter: blur(10px);
    }

    .container {
      position: relative;
      text-align: center;
      width: 90%;
      max-width: 520px;
    }

    .logo {
      font-size: 0.9rem;
      letter-spacing: 3px;
      opacity: 0.7;
      margin-bottom: 30px;
    }

    h1 {
      font-size:  3.5rem;
      font-weight: 1000;
      margin-bottom: 20px;
    }

    p {
      font-size: 1.2rem;
      opacity: 0.8;
      margin-bottom: 35px;
      line-height: 1.6;
    }

    .contact-btn a {
    display: inline-block;
      padding: 12px 60px;
      border-radius: 30px;
      background:transparent;
      color: #ffffff;
    border: 1px solid rgba(255,255,255,0.4);
      text-decoration: none;
      font-size: 0.85rem;
      letter-spacing: 0.5px;
      transition: opacity 0.3s ease, background 0.3s;
      margin-bottom: 20px; /* espace vertical au-dessus */ ease;
}

    .contact-btn a:hover {
    background: rgba(255, 255, 255, 0.15);
      background-color:#002775 ;
    }
    
   .xd-preview-btn {
      display: inline-block;
      padding: 12px 18px;
      border-radius: 30px;
      background-color: #FC5300;
      color: #ffffff;
      text-decoration: none;
      font-size: 0.85rem;
      letter-spacing: 0.5px;
      transition: opacity 0.3s ease, background 0.3s ease;
    }

    .xd-preview-btn:hover {
      background: rgba(255, 255, 255, 0.15);
      background-color:#002775 ;
    }

    .socials {
      display: none;
      padding : 20px;
      justify-content: center;
      gap: 14px;
      margin-bottom: 30px;
    }

    .socials a {
      width: 32px;
      height: 32px;
      border: 1px solid rgba(255,255,255,0.4);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      color: #fff;
      text-decoration: none;
      font-size: 0.8rem;
      opacity: 0.8;
      transition: opacity 0.3s, background 0.3s;
    }

    .socials a:hover {
      opacity: 1;
      background: rgba(255,255,255,0.15);
    }

    footer {
      font-size:1rem;
      margin-top: 1rem;
      opacity: 0.5;
    }

    @media (max-width: 480px) {
      h1 {
        font-size: 1.8rem;
      }
    }
  </style>