#action {
    width: 75%;
    padding: 5px;
}

.task {
    display: flex;
    flex-flow: row wrap;
}

.field {
    display: flex;
    flex-flow: column;
}

.field * {
    margin: 5px;
}

.text_area_output {
    width: 15em;
    height: 10em;
    resize: none;
    border: 2px solid green;
}

.text_areaKey {
    width: 15em;
    height: 5em;
    resize: none;
    border: 2px solid green;
}

.text_area {
    width: 15em;
    height: 10em;
    resize: none;
    border: 2px solid green;
}

.input_button {
    width: 10em;
    height: 2em;
}

#clearButton {
    width: 10em;
    height: 2em;
}

#changeButton {
  width: 10em;
  height: 2em;
}

.row_and_col {
    display: flex;
    flex-flow: row wrap;
}

.val_input {
    width: 7em;
    height: 2em;
}

#inputButtonrc4 {
  width: 20em;
  height: 2em;
}

.tabs {
    font-size: 0;
  }
  
  .tabs>input[type="radio"] {
    display: none;
  }
  
  .tabs>div {
    /* скрыть контент по умолчанию */
    display: none;
    border: 1px solid #e0e0e0;
    padding: 10px 15px;
    font-size: 16px;
  }
  
  /* отобразить контент, связанный с вабранной радиокнопкой (input type="radio") */
  #tab-btn-1:checked~#vigenere,
  #tab-btn-2:checked~#DES,
  #tab-btn-3:checked~#rc4 {
    display: block;
  }
  
  .tabs>label {
    display: inline-block;
    text-align: center;
    vertical-align: middle;
    user-select: none;
    background-color: #f5f5f5;
    border: 1px solid #e0e0e0;
    padding: 2px 8px;
    font-size: 16px;
    line-height: 1.5;
    transition: color 0.15s ease-in-out, background-color 0.15s ease-in-out;
    cursor: pointer;
    position: relative;
    top: 1px;
  }
  
    .tabs>label:not(:first-of-type) {
    border-left: none;
  }
  
    .tabs>input[type="radio"]:checked+label {
    background-color: #fff;
    border-bottom: 1px solid #fff;
  }