style.css

/* Define CSS variables for light mode */
:root {
    --background-color: white;
    --text-color: black;
    --button-bg-color: white;
    --button-text-color: black;
    /*--button-hover-bg-color: #0056b3;
    --button-hover-text-color: white; */
    --button-outline-color: black; /* Added outline color variable */
  }
  
  /* Dark mode variables */
  .dark-mode {
    --background-color: black;
    --text-color: white;
    --button-bg-color: black;
    --button-text-color: white;
    --button-outline-color: white; /* added outline color variable */
  }
  
  /* Apply the variables */
  body {
    background-color: var(--background-color);
    color: var(--text-color);
    display: flex;               /* it enables flexbox layout */
    justify-content: center;     /* centers items horizontally */
    align-items: center;         /* centers items vertically */
    height: 100vh;               /* makes the body take the full height of the viewport */
    margin: 0;                   /* removes default margin */
    transition: background-color 0.3s, color 0.3s;
  }
  
  
  button {
    align-items:center;
    padding: 10px 20px;
    margin: 20px;
    cursor: pointer;
    background-color: var(--button-bg-color);
    color: var(--button-text-color);
    border: 2px solid var(--button-outline-color); /* Added black outline */
    border-radius: 5px;
    font-size: 16px;
    transition: background-color 0.3s, color 0.3s, border-color 0.3s;
  }
  
  button:hover {
    background-color: var(--button-hover-bg-color);
    color: var(--button-hover-text-color);
  }