body {
    background-color: #333;
    color: #fff;
    font-family: 'Roboto', sans-serif;
    margin: 0;
    padding: 0;
}

#container {
    display: flex;
    justify-content: space-around;
    align-items: center;
    height: 100vh;
  
}

#stack-container {
   
    border: 2px solid #4CAF50;
    border-radius: 10px;
    overflow: hidden;
}

#canvas {
    margin-right: 40%;
    background-color: #333;
    transition: height 0.5s;
}

#controls {
    max-width: 400px;
    text-align: center;
}

#input-container,
#buttons-container {
    margin: 10px;
}

label {
    display: block;
    margin-bottom: 5px;
    color: #fff;
}

.input-field {
    padding: 10px;
    border-radius: 5px;
    border: 1px solid #4CAF50;
    color: black;
    font-size: 16px;
    width: 100%;
    box-sizing: border-box;
    transition: border-color 0.2s;
}

.input-field:focus {
    border-color: #fff;
    outline: none;

  box-shadow: 0 0 5px #fff;
}

.button {
    border: none;
    background: #4CAF50;
    padding: 10px;
    color: #fff;
    border-radius: 5px;
    font-weight: bold;
    font-size: 16px;
    cursor: pointer;
    transition: background-color 0.2s;
}

.button:hover {
    background-color: #3e8e41;
}

.push-button {
    margin-top: 10px;
}

.pop-button,
.peek-button {
    margin-top: 20px;
}

.button:active {
    transform: translateY(2px);
    box-shadow: 0 1px 2px #4CAF50;
}