.envelope {
      animation: float 4s ease-in-out infinite;
      width: 100%;
      height: 400px;
      margin: 10px auto;
      background: #fafafa;
      position: relative;
      box-shadow: 0 10px 24px rgba(0,0,0,0.18);
      overflow: hidden;
    }

    /* Diagonal airmail edge */
    .edge {
      position: absolute;
      inset: 0;
      border: 14px solid transparent;
      border-image: repeating-linear-gradient(
        135deg,
        deeppink 0 12px,
        #ffffff 12px 24px,
        #1f5fa8 24px 36px,
        #ffffff 36px 48px
      ) 14;
      pointer-events: none;
    }

    .content-box {
      padding: 40px 50px;
      position: relative;
    }

    /* Vintage stamp */
    .stamp {
      width: auto;
      height: auto;
      border: 3px dotted #333;
      position: absolute;
      top: 60px;
      left: 40px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 30px;
      text-align: center;
      background: #f2d3a2;
      padding: 5px;
    }

    .stamp span {
      font-weight: bold;
    }

    /* Circular postmark */
    .postmark {
      position: absolute;
    top: 50px;
    left: 50%;
    width: 90px;
    height: 90px;
    border: 5px solid #9E9E9E;
    border-radius: 50%;
    transform: rotate(-18deg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 11px;
    text-align: center;
    background: #e91e6333;
    color: #000;
    opacity: 0.5;
    }

    /* Address block */
    .address {
      position: absolute;
      right: 8%;
      top: 140px;
      left: 9%;
      color: #1f5fa8;
    }
    .footer-address {
      position: absolute;
      right: 8%;
      left: 9%;
      color: #e91e63;
      font-size: 16px;
      line-height: 42px;
    }

    .address h1 {
      font-size: 22px;
      margin: 0 0 16px 0;
      font-weight: normal;
    }

    .field {
    margin-bottom: 10px;
    padding-bottom: 4px;
    border-bottom: 1px dashed #dc3545;
    color: #dc3545;
    font-weight: bold;
    }

    /* Air Mail ribbon */
    .airmail {
        position: absolute;
        bottom: 25px;
        left: 6%;
        background: #E91E63;
        color: #fff;
        padding: 5px 37px;
        font-size: 19px;
        letter-spacing: 2px;
    }

    .airmail::after {
      content: "";
      position: absolute;
      right: -18px;
      top: 0;
      border-top: 18px solid transparent;
      border-bottom: 18px solid transparent;
      border-left: 18px solid #E91E63;
    }

    /* Decorative lines */
    .lines {
      position: absolute;
      top: 90px;
      right: 40px;
    }

    .lines div {
      animation: wave 2.5s ease-in-out infinite;
      width: 120px;
      height: 8px;
      border-top: 2px solid #ff9800;
      border-radius: 50%;
      margin-bottom: 6px;
    }
  @keyframes float {
      0% { transform: translateY(0); }
      50% { transform: translateY(-10px); }
      100% { transform: translateY(0); }
    }

    @keyframes wave {
      0% { transform: scaleX(1); }
      50% { transform: scaleX(0.85); }
      100% { transform: scaleX(1); }
    }