:root {
  --bg-app: #111111;
  --bg-panel: #1d1d1d;
  --bg-header: #242424;
  --bg-input: #0b0b0b;
  --border-color: #343434;
  --text-primary: #eeeeee;
  --text-secondary: #a7a7a7;
  --focus-color: #409eff;
  --msg-self-bg: rgba(64, 158, 255, 0.18);
  --msg-other-bg: #2a2a2a;
  --radius: 6px;
}

body.theme-white {
  --bg-app: #f2f4f7;
  --bg-panel: #ffffff;
  --bg-header: #f8fafc;
  --bg-input: #ffffff;
  --border-color: #d9dee7;
  --text-primary: #1f2937;
  --text-secondary: #667085;
  --msg-self-bg: rgba(64, 158, 255, 0.12);
  --msg-other-bg: #ffffff;
}

* { box-sizing: border-box; }
html, body {
  margin: 0;
  height: 100%;
  height: 100dvh;
  overflow: hidden;
  background: var(--bg-app);
  color: var(--text-primary);
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

.guest-shell {
  width: 100%;
  height: 100%;
  max-width: 720px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  background: var(--bg-panel);
  border-left: 1px solid var(--border-color);
  border-right: 1px solid var(--border-color);
}

.guest-header {
  min-height: 64px;
  padding: 12px 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  border-bottom: 1px solid var(--border-color);
  background: var(--bg-header);
}

.guest-eyebrow {
  font-size: 11px;
  color: var(--text-secondary);
  letter-spacing: 0.08em;
}

.guest-header h1 {
  margin: 4px 0 0;
  font-size: 17px;
  line-height: 1.25;
  font-weight: 600;
}

.guest-login-link {
  flex-shrink: 0;
  color: var(--focus-color);
  text-decoration: none;
  font-size: 13px;
  padding: 6px 8px;
  border-radius: var(--radius);
}

.guest-login-link:hover { background: rgba(64, 158, 255, 0.1); }

.guest-main {
  flex: 1;
  min-height: 0;
  display: flex;
  flex-direction: column;
}

.guest-status {
  min-height: 32px;
  padding: 8px 14px;
  border-bottom: 1px solid var(--border-color);
  color: var(--text-secondary);
  font-size: 13px;
}

.guest-status[data-tone="error"] { color: #ff6b6b; }
.guest-status[data-tone="ok"] { color: #76d672; }

.guest-messages {
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  padding: 14px;
}

.guest-message {
  display: flex;
  flex-direction: column;
  margin-bottom: 12px;
  max-width: 78%;
}

.guest-message-self {
  margin-left: auto;
  align-items: flex-end;
}

.guest-message-other {
  margin-right: auto;
  align-items: flex-start;
}

.guest-message-meta {
  margin-bottom: 4px;
  font-size: 11px;
  color: var(--text-secondary);
}

.guest-message-content {
  padding: 9px 11px;
  border-radius: var(--radius);
  line-height: 1.55;
  font-size: 14px;
  white-space: pre-wrap;
  word-break: break-word;
  border: 1px solid transparent;
}

.guest-message-self .guest-message-content {
  background: var(--msg-self-bg);
  border-color: rgba(64, 158, 255, 0.24);
}

.guest-message-other .guest-message-content {
  background: var(--msg-other-bg);
  border-color: var(--border-color);
}

.guest-form {
  flex-shrink: 0;
  display: flex;
  gap: 8px;
  padding: 10px;
  border-top: 1px solid var(--border-color);
  background: var(--bg-header);
}

.guest-input {
  flex: 1;
  min-width: 0;
  height: 38px;
  padding: 0 12px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  background: var(--bg-input);
  color: var(--text-primary);
  font-size: 14px;
}

.guest-input:focus {
  outline: none;
  border-color: var(--focus-color);
}

.guest-send {
  width: 72px;
  border: none;
  border-radius: var(--radius);
  background: var(--focus-color);
  color: #fff;
  font-size: 14px;
  cursor: pointer;
}

.guest-send:disabled,
.guest-input:disabled {
  opacity: 0.55;
  cursor: not-allowed;
}

@media (max-width: 520px) {
  .guest-shell { border: none; }
  .guest-header { min-height: 58px; padding: 10px 12px; }
  .guest-header h1 { font-size: 16px; }
  .guest-login-link { font-size: 12px; }
  .guest-messages { padding: 12px; }
  .guest-message { max-width: 86%; }
}