body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f8f9fa;
    margin: 0;
    padding: 20px;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    background-color: #fff;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.05);
}

h1 {
    text-align: center;
    color: #212529;
    margin-bottom: 1.5rem;
}

.panels {
    margin-bottom: 1.5rem;
}

.panel:first-child {
    margin-bottom: 1rem;
}

textarea {
    width: 100%;
    height: 250px;
    padding: 1rem;
    border: 1px solid #ced4da;
    border-radius: 6px;
    font-family: 'Courier New', Courier, monospace;
    font-size: 0.9rem;
    box-sizing: border-box;
    resize: vertical;
}

.controls {
    text-align: center;
    margin-bottom: 1.5rem;
}

.controls button {
    font-size: 1rem;
    padding: 0.75rem 1.5rem;
    margin: 0 0.5rem;
    cursor: pointer;
    border: none;
    border-radius: 6px;
    transition: background-color 0.2s ease;
}

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

#compare-btn:hover {
    background-color: #0056b3;
}

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

#clear-btn:hover {
    background-color: #5a6268;
}

#diff-output {
    background-color: #f8f9fa;
    border: 1px solid #dee2e6;
    border-radius: 6px;
    padding: 1.5rem;
    min-height: 100px;
    white-space: pre-wrap;
    word-break: break-all;
    font-family: 'Courier New', Courier, monospace;
    font-size: 0.9rem;
    line-height: 1.5;
}

ins {
    background-color: #d4ffb4;
    color: #004d00;
    text-decoration: none;
}

del {
    background-color: #ffb4b4;
    color: #6a0000;
    text-decoration: line-through;
}

.content {
    margin-top: 3rem;
    color: #495057;
}

.content h2 {
    color: #343a40;
    border-bottom: 2px solid #e9ecef;
    padding-bottom: 0.5rem;
    margin-top: 2rem;
}

.content h3 {
    color: #495057;
    margin-top: 1.5rem;
}

.content ul {
    padding-left: 20px;
}