* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --success-color: #10b981;
    --error-color: #ef4444;
    --bg-color: #0f172a;
    --surface-color: #1e293b;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --border-color: #334155;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 2rem;
    flex: 1;
}

header {
    text-align: center;
    padding: 2rem 0 3rem;
    border-bottom: 1px solid var(--border-color);
}

header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    background: linear-gradient(135deg, #3b82f6, #8b5cf6);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

main {
    padding: 3rem 0;
}

.lab-section {
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 2rem;
    margin-bottom: 2rem;
}

.lab-section h2 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.lab-section p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

.lab-section.info ul {
    list-style-position: inside;
    color: var(--text-secondary);
}

.lab-section.info ul li {
    padding: 0.25rem 0;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    font-weight: 500;
    border-radius: 6px;
    cursor: pointer;
    transition: background 0.2s ease;
}

.btn-primary:hover:not(:disabled) {
    background: var(--primary-hover);
}

.btn-primary:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.response-box {
    margin-top: 1.5rem;
    padding: 1rem;
    border-radius: 6px;
    border: 1px solid var(--border-color);
    background: #0a0f1e;
}

.response-box.hidden {
    display: none;
}

.response-box h3 {
    font-size: 1rem;
    margin-bottom: 0.75rem;
    color: var(--text-secondary);
}

.response-box pre {
    background: #000;
    padding: 1rem;
    border-radius: 4px;
    overflow-x: auto;
    font-family: 'Courier New', Courier, monospace;
    font-size: 0.9rem;
    line-height: 1.4;
    color: #a5f3fc;
}

.response-box.success {
    border-color: var(--success-color);
}

.response-box.error {
    border-color: var(--error-color);
}

.response-box.blocked {
    border-color: #f59e0b;
}

.hint {
    font-size: 0.85rem;
    color: #64748b;
    margin-bottom: 1rem !important;
}

.chat-textarea {
    width: 100%;
    background: #0a0f1e;
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 0.75rem;
    font-family: 'Courier New', Courier, monospace;
    font-size: 0.95rem;
    line-height: 1.5;
    resize: vertical;
    margin-bottom: 1rem;
    display: block;
}

.chat-textarea:focus {
    outline: none;
    border-color: var(--primary-color);
}

footer {
    text-align: center;
    padding: 2rem 0;
    border-top: 1px solid var(--border-color);
    color: var(--text-secondary);
    font-size: 0.9rem;
}

@media (max-width: 768px) {
    .container {
        padding: 1rem;
    }

    header h1 {
        font-size: 2rem;
    }

    .lab-section {
        padding: 1.5rem;
    }
}