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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.container {
    background: white;
    border-radius: 12px;
    box-shadow: 0 20px 60px rgba(0,0,0,0.3);
    max-width: 800px;
    width: 100%;
    overflow: hidden;
}

.header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 30px;
    text-align: center;
}

.header h1 {
    font-size: 2em;
    margin-bottom: 10px;
}

.header p {
    opacity: 0.9;
}

.content {
    padding: 30px;
}

.status-bar {
    background: #f8f9fa;
    padding: 15px;
    border-radius: 8px;
    margin-bottom: 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.status-indicator {
    display: flex;
    align-items: center;
    gap: 8px;
}

.status-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: #6c757d;
}

.status-dot.connected {
    background: #28a745;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

.button {
    background: #667eea;
    color: white;
    border: none;
    padding: 12px 24px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 1em;
    transition: background 0.3s;
}

.button:hover {
    background: #764ba2;
}

.button:disabled {
    background: #ccc;
    cursor: not-allowed;
}

.button.secondary {
    background: #6c757d;
}

.button.secondary:hover {
    background: #5a6268;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #333;
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 12px;
    border: 2px solid #e0e0e0;
    border-radius: 6px;
    font-size: 1em;
    transition: border-color 0.3s;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: #667eea;
}

.form-group textarea {
    resize: vertical;
    min-height: 100px;
}

.messages-container {
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    padding: 20px;
    max-height: 400px;
    overflow-y: auto;
    margin-bottom: 20px;
    background: #f8f9fa;
}

.message {
    background: white;
    padding: 15px;
    border-radius: 8px;
    margin-bottom: 12px;
    border-left: 4px solid #667eea;
}

.message.received {
    border-left-color: #28a745;
}

.message.sent {
    border-left-color: #667eea;
}

.message-header {
    display: flex;
    justify-content: space-between;
    margin-bottom: 8px;
    font-size: 0.9em;
    color: #666;
}

.message-sender {
    font-weight: 600;
    color: #667eea;
    word-break: break-all;
}

.message-time {
    color: #999;
}

.message-body {
    color: #333;
    line-height: 1.5;
}

.alert {
    padding: 15px;
    border-radius: 6px;
    margin-bottom: 20px;
}

.alert.error {
    background: #f8d7da;
    border: 1px solid #f5c6cb;
    color: #721c24;
}

.alert.success {
    background: #d4edda;
    border: 1px solid #c3e6cb;
    color: #155724;
}

.alert.info {
    background: #d1ecf1;
    border: 1px solid #bee5eb;
    color: #0c5460;
}

.hidden {
    display: none;
}

.loading {
    text-align: center;
    padding: 20px;
    color: #667eea;
}

.spinner {
    border: 3px solid #f3f3f3;
    border-top: 3px solid #667eea;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    animation: spin 1s linear infinite;
    margin: 0 auto 10px;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.footer {
    background: #f8f9fa;
    padding: 20px;
    text-align: center;
    border-top: 1px solid #e0e0e0;
}

.footer a {
    color: #667eea;
    text-decoration: none;
}

.footer a:hover {
    text-decoration: underline;
}

.actions {
    display: flex;
    gap: 10px;
    margin-top: 15px;
}

.version-info {
    font-size: 0.85em;
    color: #999;
    margin-top: 5px;
}