body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: #f4f7f9;
    color: #333;
    margin: 0;
    padding: 20px;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    background-color: #fff;
    padding: 20px 40px;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
}

h1, h2, h3 {
    color: #1a202c;
}

h1 {
    text-align: center;
    margin-bottom: 30px;
}

textarea {
    width: 100%;
    height: 250px;
    padding: 10px;
    border: 1px solid #ccc;
    border-radius: 4px;
    font-size: 1rem;
    margin-bottom: 15px;
    box-sizing: border-box; /* Important for width: 100% */
}

.controls {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-bottom: 15px;
}

button {
    padding: 12px 20px;
    font-size: 1rem;
    font-weight: bold;
    cursor: pointer;
    border: none;
    border-radius: 4px;
    background-color: #007bff;
    color: white;
    transition: background-color 0.2s;
}

button:hover {
    background-color: #0056b3;
}

#decode-btn {
    background-color: #28a745;
}

#decode-btn:hover {
    background-color: #1e7e34;
}

.extra-controls {
    display: flex;
    justify-content: flex-end;
    gap: 10px;
    margin-bottom: 30px;
}

.extra-controls button {
    background-color: #6c757d;
    font-weight: normal;
    padding: 8px 15px;
}

.extra-controls button:hover {
    background-color: #5a6268;
}

.content {
    margin-top: 40px;
    line-height: 1.6;
}

.content h2 {
    border-bottom: 2px solid #eee;
    padding-bottom: 10px;
    margin-top: 30px;
}

.content code {
    background-color: #e9ecef;
    padding: 2px 5px;
    border-radius: 4px;
    font-family: "Courier New", Courier, monospace;
}