* { box-sizing: border-box; margin: 0; padding: 0; }
body { background: #0d1117; color: #c9d1d9; font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif; height: 100vh; }

.login-box {
  max-width: 320px; margin: 15vh auto; background: #161b22; border: 1px solid #30363d;
  border-radius: 10px; padding: 32px;
}
.login-box h1 { font-size: 20px; margin-bottom: 20px; }
.login-box form { display: flex; flex-direction: column; gap: 12px; }
.login-box input {
  padding: 10px 12px; background: #0d1117; border: 1px solid #30363d; border-radius: 6px;
  color: #c9d1d9; font-size: 14px;
}
.login-box button {
  padding: 10px; background: #238636; border: none; border-radius: 6px; color: white;
  font-size: 14px; cursor: pointer;
}
.login-box .error { color: #f85149; font-size: 13px; margin-bottom: 12px; }

.app { display: flex; height: 100vh; }
.sidebar {
  width: 220px; background: #161b22; border-right: 1px solid #30363d;
  padding: 20px 14px; display: flex; flex-direction: column; gap: 6px; flex-shrink: 0;
}
.who { font-size: 14px; margin-bottom: 16px; color: #f0f6fc; }
.logout { float: right; font-size: 12px; color: #8b949e; }
.skills-label { font-size: 11px; color: #8b949e; text-transform: uppercase; letter-spacing: .08em; margin-bottom: 4px; }
.skill-btn {
  text-align: left; padding: 8px 10px; background: #0d1117; border: 1px solid #30363d;
  border-radius: 6px; color: #c9d1d9; font-size: 13px; cursor: pointer;
}
.skill-btn.active { border-color: #58a6ff; color: #58a6ff; }
.no-skills { font-size: 13px; color: #8b949e; }

.chat { flex: 1; display: flex; flex-direction: column; min-width: 0; }
.messages { flex: 1; overflow-y: auto; padding: 24px; display: flex; flex-direction: column; gap: 14px; }
.msg { max-width: 70%; padding: 10px 14px; border-radius: 10px; font-size: 14px; line-height: 1.5; white-space: pre-wrap; }
.msg.user { align-self: flex-end; background: #1f6feb; color: white; }
.msg.assistant { align-self: flex-start; background: #161b22; border: 1px solid #30363d; }
.msg.error { align-self: flex-start; background: #3d1f1f; border: 1px solid #f85149; color: #ffb3ab; }
.msg.pending { opacity: .6; }

.chat-form { display: flex; gap: 10px; padding: 16px 24px; border-top: 1px solid #30363d; }
.chat-form input {
  flex: 1; padding: 12px 14px; background: #161b22; border: 1px solid #30363d; border-radius: 8px;
  color: #c9d1d9; font-size: 14px;
}
.chat-form button {
  padding: 12px 20px; background: #238636; border: none; border-radius: 8px; color: white; cursor: pointer;
}
.chat-form button:disabled, .chat-form input:disabled { opacity: .5; cursor: not-allowed; }