:root {
    --background-body: #fff;
    --background: #efefef;
    --text-main: #363636;
    --text-bright: #000;
    --links: #0076d1;
    --focus: #0096bfab;
    --button-base: #d0cfcf;
    --button-hover: #9b9b9b;
    --form-text: #1d1d1d;
    --animation-duration: 0.1s;
  }
  
  body.dark-mode {
    --background-body: #202b38;
    --background: #161f27;
    --text-main: #dbdbdb;
    --text-bright: #fff;
    --links: #41adff;
    --focus: #0096bfab;
    --button-base: #0c151c;
    --button-hover: #040a0f;
    --form-text: #fff;
  }
  
  body {
    font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 
      'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue', 
      'Segoe UI Emoji', 'Apple Color Emoji', 'Noto Color Emoji', sans-serif;
    line-height: 1.4;
    max-width: 800px;
    margin: 20px auto;
    padding: 0 10px;
    color: var(--text-main);
    background: var(--background-body);
  }
  
  h1 {
    font-size: 2.2em;
    margin-top: 0;
    margin-bottom: 12px;
    color: var(--text-bright);
  }
  
  p, label {
    margin-bottom: 12px;
  }
  
  a {
    text-decoration: none;
    color: var(--links);
  }
  
  a:hover {
    text-decoration: underline;
  }
  
  input, button {
    font-family: inherit;
    font-size: inherit;
    padding: 10px;
    border: none;
    border-radius: 6px;
    background: var(--background);
    color: var(--form-text);
    transition:
      background-color var(--animation-duration) linear,
      border-color var(--animation-duration) linear,
      color var(--animation-duration) linear,
      box-shadow var(--animation-duration) linear,
      transform var(--animation-duration) ease;
    margin-bottom: 6px;
    outline: none;
  }
  
  /* Centrar el texto dentro del campo de texto */
  input[type="text"] {
    width: 100%;
    text-align: center; 
  }
  
  input:focus, button:focus {
    box-shadow: 0 0 0 2px var(--focus);
  }
  
  button {
    background-color: var(--button-base);
    cursor: pointer;
  }
  
  button:hover {
    background: var(--button-hover);
  }
  
  /* Zona de arrastre */
  #drop-zone {
    border: 2px dashed #ccc;
    border-radius: 10px;
    padding: 40px;
    text-align: center;
    color: #999;
    margin-top: 20px;
    cursor: pointer;
  }
  
  body.dark-mode #drop-zone {
    border-color: #526980;
    color: #a9b1ba;
  }
  
  #drop-zone.dragover {
    border-color: #666;
    background: #f2f2f2;
    color: #333;
  }
  
  body.dark-mode #drop-zone.dragover {
    border-color: #526980;
    background: #1a242f;
    color: #dbdbdb;
  }
  
  /* Spinner (loader) */
  #loader {
    border: 16px solid #f3f3f3;
    border-top: 16px solid #3498db;
    border-radius: 50%;
    width: 80px;
    height: 80px;
    animation: spin 1s linear infinite;
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    z-index: 999;
    display: none;
  }
  
  @keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
  }
  
  /* Botón flotante para cambiar tema */
  #theme-toggle-button {
    position: fixed;
    top: 20px;
    right: 20px;
    background: var(--button-base);
    border-radius: 50%;
    width: 50px;
    height: 50px;
    font-size: 24px;
    line-height: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background var(--animation-duration) linear;
    box-shadow: 0 2px 5px rgba(0,0,0,0.2);
  }