/* Default light theme */
:root {
    --bg-color: #f5f5f5;
    --text-color: #333;
    --button-bg: #007bff;
    --button-hover-bg: #0056b3;
    --input-border: #ccc;
    --input-focus-border: #007bff;
    --result-bg: #fff;
    --result-shadow: rgba(0,0,0,0.1);
  }
  
  /* Dark theme variables */
  [data-theme="dark"] {
    --bg-color: #333;
    --text-color: #f5f5f5;
    --button-bg: #444;
    --button-hover-bg: #222;
    --input-border: #777;
    --input-focus-border: #44c;
    --result-bg: #444;
    --result-shadow: rgba(0,0,0,0.3);
  }
  
  * {
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  }
  
  body {
    background: var(--bg-color);
    color: var(--text-color);
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    flex-direction: column;
  }
  
  .container {
    text-align: center;
    max-width: 500px;
    width: 100%;
  }
  
  h1 {
    margin-bottom: 20px;
    font-size: 2em;
  }
  
  input {
    padding: 10px 15px;
    font-size: 16px;
    border: 2px solid var(--input-border);
    border-radius: 8px;
    width: 250px;
    margin-right: 10px;
    outline: none;
    transition: 0.2s ease;
  }
  
  input:focus {
    border-color: var(--input-focus-border);
  }
  
  button {
    padding: 10px 15px;
    background-color: var(--button-bg);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    cursor: pointer;
    transition: background-color 0.2s ease;
    margin-top: 10px;
  }
  
  button:hover {
    background-color: var(--button-hover-bg);
  }
  
  #result {
    margin-top: 30px;
    background-color: var(--result-bg);
    padding: 20px;
    border-radius: 12px;
    box-shadow: 0 4px 8px var(--result-shadow);
    color: var(--text-color);
    max-width: 400px;
    width: 100%;
  }
  
  p {
    margin: 10px 0;
  }
  
  h2 {
    margin-bottom: 10px;
  }
  
  #toggleMode {
    margin-top: 20px;
    background-color: #f5f5f5;
    color: #333;
    padding: 10px 20px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
  }
  
  #toggleMode:hover {
    background-color: #ccc;
  }