body {
    font-family: 'Roboto', sans-serif;
    background-color: #f4f5f7;
    color: #333;
    margin: 0;
    padding: 20px;
    line-height: 1.7;
    background-image: url('data:image/svg+xml,%3Csvg width="60" height="60" viewBox="0 0 60 60" xmlns="http://www.w3.org/2000/svg"%3E%3Cg fill="none" fill-rule="evenodd"%3E%3Cg fill="%23e9ebef" fill-opacity="0.4"%3E%3Cpath d="M36 34.01V37.5h-1.5V34.01a3 3 0 0 0-3-3H27.5v-1.5h3.99a3 3 0 0 0 3.01-3V22.5h1.5v3.99a3 3 0 0 0 3 3H40.5v1.5H36.01a3 3 0 0 0-3.01 3zM42 22.5V26h4.5V22.5H42z"/%3E%3C/g%3E%3C/g%3E%3C/svg%3E');
}

.app-container {
    max-width: 800px;
    margin: 20px auto;
    padding: 40px;
    background: #fff;
    border-radius: 12px;
    box-shadow: 0 10px 25px rgba(0,0,0,0.1), 0 5px 10px rgba(0,0,0,0.05);
}

.app-header {
    text-align: center;
    margin-bottom: 40px;
    padding-bottom: 20px;
    border-bottom: 1px solid #eee;
}

.app-header h1 {
    font-size: 2.8rem;
    font-weight: 900;
    color: #111;
}

.app-header p {
    font-size: 1.2rem;
    color: #666;
}

.crypto-tool {
    margin-bottom: 40px;
    padding: 30px;
    background: #f8f9fa;
    border-radius: 12px;
}

.input-group, .output-group {
    margin-bottom: 25px;
}

.input-group label, .output-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 700;
    color: #333;
}

.input-group textarea,
.input-group input,
.output-group textarea {
    width: 100%;
    padding: 12px;
    font-size: 1.1rem;
    border: 1px solid #ddd;
    border-radius: 8px;
    box-sizing: border-box;
    resize: vertical;
}

.output-group textarea {
    background-color: #e9ecef;
    cursor: not-allowed;
}

.controls {
    text-align: center;
    margin-bottom: 25px;
}

.btn {
    padding: 12px 25px;
    font-size: 1.1rem;
    font-weight: 700;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s ease-in-out;
    margin: 0 10px;
}

.btn-primary {
    background-color: #007bff;
    color: white;
}

.btn-primary:hover {
    background-color: #0056b3;
    box-shadow: 0 4px 15px rgba(0, 123, 255, 0.4);
}

.btn-secondary {
    background-color: #6c757d;
    color: white;
}

.btn-secondary:hover {
    background-color: #5a6268;
    box-shadow: 0 4px 15px rgba(108, 117, 125, 0.4);
}

.status-message {
    margin-top: 15px;
    padding: 10px;
    border-radius: 8px;
    text-align: center;
    font-weight: 500;
    display: none; /* Initially hidden */
}

.status-message.success {
    background-color: #d4edda;
    color: #155724;
    display: block;
}

.status-message.error {
    background-color: #f8d7da;
    color: #721c24;
    display: block;
}

.content-guide h2 {
    font-size: 1.8rem;
    color: #0056b3;
    margin-top: 30px;
    border-bottom: 2px solid #e0e0e0;
    padding-bottom: 10px;
}

.content-guide p, .content-guide ul, .content-guide ol {
    font-size: 1.1rem;
    color: #555;
    line-height: 1.8;
}

.content-guide ul, .content-guide ol {
    padding-left: 25px;
}

.content-guide code {
    background-color: #e9ebef;
    padding: 3px 6px;
    border-radius: 4px;
    font-family: monospace;
}

@media (max-width: 600px) {
    .app-header h1 {
        font-size: 2rem;
    }
    .app-container {
        padding: 20px;
    }
    .controls {
        display: flex;
        flex-direction: column;
        gap: 15px;
    }
}