/* Estilos originales mantenidos */
      body {
        background: #f8fcff;
        font-family: "Segoe UI", Arial, sans-serif;
        margin: 0;
        color: #233;
      }
      .container {
        max-width: 350px;
        margin: 26px auto 0 auto;
        background: #fff;
        border-radius: 17px;
        box-shadow: 0 4px 22px #2a6fe433;
        padding: 16px 10px 18px 10px;
      }
      .logo {
        font-size: 1.4em;
        text-align: center;
        color: #176dd7;
        font-weight: bold;
        margin-bottom: 8px;
      }
      .desc {
        text-align: center;
        color: #187;
        margin-bottom: 14px;
        font-size: 0.86em;
      }
      #uploadBtn {
        display: block;
        width: 100%;
        margin: 0 auto 18px auto;
        font-size: 1.15em;
        padding: 13px 0;
        border-radius: 10px;
        background: #2976d3;
        color: #fff;
        border: none;
        font-weight: bold;
        cursor: pointer;
      }
      .preview-wrap {
        text-align: center;
        margin-bottom: 14px;
      }
      #previewImg {
        max-width: 98%;
        max-height: 260px;
        border-radius: 9px;
        background: #e0e9f3;
        border: 1.3px solid #b9daf8;
      }
      .slider-row {
        display: flex;
        align-items: center;
        gap: 7px;
        margin: 8px 0;
      }
      .slider-label {
        min-width: 44px;
        color: #19788a;
        font-size: 1.04em;
      }
      .slider-val {
        width: 38px;
        text-align: center;
        font-size: 1.06em;
      }
      input[type="range"] {
        flex: 1;
        accent-color: #176dd7;
      }
      .input-row {
        display: flex;
        align-items: center;
        gap: 7px;
        margin: 8px 0;
      }
      input[type="text"] {
        flex: 1;
        font-size: 1.1em;
        border-radius: 7px;
        border: 1.2px solid #b9daf8;
        padding: 6px 8px;
      }
      .action-btn {
        width: 100%;
        background: #1dc78a;
        color: #fff;
        border: none;
        border-radius: 9px;
        font-size: 1.18em;
        font-weight: bold;
        padding: 13px 0;
        margin: 13px 0 8px 0;
        cursor: pointer;
      }
      .action-btn:active {
        background: #16a374;
      }
      .download-btn {
        background: #2976d3;
        color: #fff;
        border: none;
        border-radius: 7px;
        font-size: 1.08em;
        padding: 9px 14px;
        cursor: pointer;
      }
      section#faq {
        background: #f0f7fc;
        border-radius: 15px;
        padding: 18px 14px 13px 16px;
        margin: 30px 0 0 0;
        border: 1px solid #b9daf8;
        font-size: 0.99em;
      }
      section#faq h3 {
        font-weight: bold;
        color: #176dd7;
        margin-bottom: 6px;
        font-size: 1.08em;
        text-align: center;
      }
      section#faq dt {
        color: #195269;
        margin-top: 10px;
        margin-bottom: 2px;
        font-weight: 500;
      }
      section#faq dd {
        color: #265a7a;
        margin-left: 7px;
        margin-bottom: 7px;
      }
      .footer {
        color: #789;
        text-align: center;
        font-size: 0.93em;
        margin-top: 10px;
      }
      #backBtn {
        position: fixed;
        left: 50%;
        bottom: 32px;
        transform: translateX(-50%);
        background: #2976d3;
        color: #fff;
        font-weight: 700;
        border: none;
        border-radius: 2rem;
        padding: 0.58em 1.5em;
        box-shadow: 0 4px 16px #2976d366;
        font-size: 1.09em;
        text-decoration: none;
        cursor: pointer;
        letter-spacing: 0.01em;
        transition:
          background 0.15s,
          transform 0.12s;
        z-index: 2000;
      }
      #backBtn:hover {
        background: #154c99;
        transform: translateX(-50%) scale(1.04);
      }
      @media (max-width: 600px) {
        .container {
          max-width: 99vw;
          padding: 9px 2vw 13px 2vw;
        }
        #backBtn {
          bottom: 18px;
          font-size: 0.98em;
          padding: 0.48em 1em;
        }
        #previewImg {
          max-width: 97vw;
          max-height: 45vw;
        }
      }