:root {
  --bg: var(--tg-theme-bg-color, #ffffff);
  --text: var(--tg-theme-text-color, #1c1c1e);
  --hint: var(--tg-theme-hint-color, #8e8e93);
  --link: var(--tg-theme-link-color, #2481cc);
  --button: var(--tg-theme-button-color, #2481cc);
  --button-text: var(--tg-theme-button-text-color, #ffffff);
  --secondary-bg: var(--tg-theme-secondary-bg-color, #f2f2f7);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  height: 100%;
}

#app {
  display: flex;
  flex-direction: column;
  height: 100vh;
}

.header {
  padding: 14px 16px 10px;
  border-bottom: 1px solid color-mix(in srgb, var(--hint) 20%, transparent);
}

.header h1 {
  font-size: 17px;
  font-weight: 600;
  margin: 0;
}

.header .subtitle {
  font-size: 12px;
  color: var(--hint);
  margin-top: 2px;
}

.tabs {
  display: flex;
  border-bottom: 1px solid color-mix(in srgb, var(--hint) 20%, transparent);
  background: var(--secondary-bg);
}

.tab {
  flex: 1;
  padding: 10px 4px;
  text-align: center;
  font-size: 12px;
  color: var(--hint);
  cursor: pointer;
  border: none;
  background: none;
  border-bottom: 2px solid transparent;
}

.tab.active {
  color: var(--link);
  border-bottom-color: var(--button);
  font-weight: 600;
}

.content {
  flex: 1;
  overflow-y: auto;
  padding: 12px;
}

.card {
  background: var(--secondary-bg);
  border-radius: 14px;
  padding: 14px 16px;
  margin-bottom: 10px;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.04);
}

.msg { margin-bottom: 12px; display: flex; }
.msg.user { justify-content: flex-end; }
.msg .bubble {
  max-width: 85%;
  padding: 10px 14px;
  border-radius: 16px;
  font-size: 14.5px;
  line-height: 1.45;
  white-space: pre-wrap;
  word-wrap: break-word;
}
.msg.user .bubble {
  background: var(--button);
  color: var(--button-text);
  border-bottom-right-radius: 4px;
}
.msg.assistant .bubble {
  background: var(--secondary-bg);
  border-bottom-left-radius: 4px;
}
.msg .bubble :is(p) { margin: 0 0 8px; }
.msg .bubble :is(p):last-child { margin-bottom: 0; }
.msg .bubble a { color: var(--link); }

.sources {
  font-size: 11.5px;
  color: var(--hint);
  margin-top: 4px;
  padding: 0 4px;
}

.chat-input-bar {
  display: flex;
  gap: 8px;
  padding: 10px 12px;
  border-top: 1px solid color-mix(in srgb, var(--hint) 20%, transparent);
}

.chat-input-bar textarea {
  flex: 1;
  resize: none;
  border: 1px solid color-mix(in srgb, var(--hint) 30%, transparent);
  border-radius: 12px;
  padding: 10px 12px;
  font-size: 14.5px;
  font-family: inherit;
  background: var(--bg);
  color: var(--text);
  max-height: 100px;
}

button.primary {
  background: var(--button);
  color: var(--button-text);
  border: none;
  border-radius: 12px;
  padding: 0 18px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
}

button.primary:disabled { opacity: 0.5; }

.banner {
  background: color-mix(in srgb, #ff9500 15%, var(--secondary-bg));
  border: 1px solid color-mix(in srgb, #ff9500 40%, transparent);
  border-radius: 12px;
  padding: 10px 14px;
  font-size: 13px;
  margin-bottom: 10px;
}

.kb-list-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
}

.kb-list-item .chev { color: var(--hint); }

.markdown-body h1, .markdown-body h2, .markdown-body h3 {
  margin-top: 1.2em;
}
.markdown-body :first-child { margin-top: 0; }
.markdown-body code {
  background: color-mix(in srgb, var(--hint) 15%, transparent);
  padding: 1px 5px;
  border-radius: 4px;
  font-size: 13px;
}
.markdown-body pre {
  background: color-mix(in srgb, var(--hint) 12%, transparent);
  padding: 10px;
  border-radius: 8px;
  overflow-x: auto;
}

.back-link {
  display: inline-block;
  margin-bottom: 10px;
  color: var(--link);
  cursor: pointer;
  font-size: 14px;
}

.form-field { margin-bottom: 12px; }
.form-field label {
  display: block;
  font-size: 12.5px;
  color: var(--hint);
  margin-bottom: 4px;
}
.form-field input, .form-field textarea {
  width: 100%;
  border: 1px solid color-mix(in srgb, var(--hint) 30%, transparent);
  border-radius: 10px;
  padding: 10px 12px;
  font-size: 14.5px;
  font-family: inherit;
  background: var(--bg);
  color: var(--text);
}

.footer-link {
  text-align: center;
  padding: 10px;
  font-size: 11.5px;
  color: var(--hint);
}
.footer-link a { color: var(--hint); }

.empty-state {
  text-align: center;
  color: var(--hint);
  padding: 40px 20px;
  font-size: 14px;
}