:root {
    --bg-color: #0d1117;
    --card-bg: #161b22;
    --input-bg: #21262d;
    --border-color: #30363d;
    --text-main: #c9d1d9;
    --text-muted: #8b949e;
    --accent-color: #2f81f7;
    --accent-hover: #58a6ff;
    --user-msg-bg: #1f6feb;
    --ai-msg-bg: #21262d;
    --error-bg: #782323;
    --radius: 12px;
    --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  }
  
  * {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
  }
  
  body {
    background-color: var(--bg-color);
    color: var(--text-main);
    font-family: var(--font-family);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 16px;
  }
  
  .app-container {
    width: 100%;
    max-width: 800px;
    height: 90vh;
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    display: flex;
    flex-direction: column;
    overflow: hidden;
    box-shadow: 0 12px 32px rgba(0, 0, 0, 0.5);
  }
  
  /* Header */
  .app-header {
    padding: 16px 20px;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    background-color: rgba(22, 27, 34, 0.8);
    backdrop-filter: blur(8px);
  }
  
  .brand {
    display: flex;
    align-items: center;
    gap: 10px;
  }
  
  .brand h1 {
    font-size: 1.1rem;
    font-weight: 600;
    color: #fff;
  }
  
  .status-indicator {
    width: 8px;
    height: 8px;
    background-color: #238636;
    border-radius: 50%;
    box-shadow: 0 0 8px #238636;
  }
  
  .badge {
    font-size: 0.75rem;
    background-color: var(--input-bg);
    border: 1px solid var(--border-color);
    color: var(--text-muted);
    padding: 4px 8px;
    border-radius: 20px;
  }
  
  /* Area de Chat */
  .chat-log {
    flex: 1;
    padding: 20px;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 16px;
  }
  
  .message {
    display: flex;
    gap: 12px;
    max-width: 85%;
    animation: fadeIn 0.2s ease-in-out;
  }
  
  .message.user {
    align-self: flex-end;
    flex-direction: row-reverse;
  }
  
  .message.ai, .message.system, .message.error {
    align-self: flex-start;
  }
  
  .avatar {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background-color: var(--input-bg);
    border: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
    flex-shrink: 0;
  }
  
  .content {
    padding: 12px 16px;
    border-radius: var(--radius);
    font-size: 0.95rem;
    line-height: 1.5;
    word-break: break-word;
  }
  
  .message.user .content {
    background-color: var(--user-msg-bg);
    color: #ffffff;
    border-bottom-right-radius: 2px;
  }
  
  .message.ai .content, .message.system .content {
    background-color: var(--ai-msg-bg);
    border: 1px solid var(--border-color);
    border-bottom-left-radius: 2px;
  }
  
  .message.error .content {
    background-color: var(--error-bg);
    color: #ffffff;
    border: 1px solid #f85149;
  }
  
  /* Footer & Form */
  .app-footer {
    padding: 16px 20px;
    border-top: 1px solid var(--border-color);
  }
  
  .input-container {
    display: flex;
    gap: 10px;
  }
  
  input[type="text"] {
    flex: 1;
    background-color: var(--input-bg);
    border: 1px solid var(--border-color);
    color: var(--text-main);
    padding: 12px 16px;
    border-radius: 8px;
    font-size: 0.95rem;
    outline: none;
    transition: border-color 0.2s;
  }
  
  input[type="text"]:focus {
    border-color: var(--accent-color);
  }
  
  button[type="submit"] {
    background-color: var(--accent-color);
    color: #ffffff;
    border: none;
    padding: 0 16px;
    border-radius: 8px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background-color 0.2s;
  }
  
  button[type="submit"]:hover {
    background-color: var(--accent-hover);
  }
  
  button[type="submit"]:disabled {
    opacity: 0.5;
    cursor: not-allowed;
  }
  
  /* Animações e Efeitos */
  @keyframes fadeIn {
    from { opacity: 0; transform: translateY(6px); }
    to { opacity: 1; transform: translateY(0); }
  }
  
  .typing-indicator {
    display: flex;
    gap: 4px;
    align-items: center;
    padding: 4px 0;
  }
  
  .typing-dot {
    width: 6px;
    height: 6px;
    background-color: var(--text-muted);
    border-radius: 50%;
    animation: pulse 1.4s infinite ease-in-out;
  }
  
  .typing-dot:nth-child(2) { animation-delay: 0.2s; }
  .typing-dot:nth-child(3) { animation-delay: 0.4s; }
  
  @keyframes pulse {
    0%, 100% { transform: scale(1); opacity: 0.4; }
    50% { transform: scale(1.3); opacity: 1; }
  }