:root {
  --bg: #f6f7f9;
  --panel: #ffffff;
  --text: #1c2430;
  --muted: #687385;
  --line: #e2e6ec;
  --accent: #0f5ea8;
  --accent-text: #ffffff;
  --mine: #e8f1fb;
  --error: #b42318;
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #12161c;
    --panel: #1a2029;
    --text: #e6eaf0;
    --muted: #98a2b3;
    --line: #2a323e;
    --accent: #4c9be8;
    --accent-text: #0b1320;
    --mine: #1e3048;
    --error: #f97066;
  }
}

* {
  box-sizing: border-box;
}

html,
body {
  height: 100%;
  margin: 0;
}

body {
  display: flex;
  flex-direction: column;
  background: var(--bg);
  color: var(--text);
  font:
    15px/1.6 system-ui,
    'Segoe UI',
    Tahoma,
    sans-serif;
}

[hidden] {
  display: none !important;
}

.bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding-block: 10px;
  padding-inline: 16px;
  background: var(--panel);
  border-block-end: 1px solid var(--line);
}

.bar h1 {
  margin: 0;
  font-size: 18px;
}

.bar-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

button,
.button {
  padding-block: 8px;
  padding-inline: 14px;
  border: 0;
  border-radius: 8px;
  background: var(--accent);
  color: var(--accent-text);
  font: inherit;
  text-decoration: none;
  cursor: pointer;
}

button:disabled {
  opacity: 0.6;
  cursor: default;
}

button.ghost {
  background: transparent;
  color: var(--accent);
  border: 1px solid var(--line);
}

.center {
  display: flex;
  flex: 1;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 16px;
  padding: 16px;
  text-align: center;
}

.layout {
  display: flex;
  flex: 1;
  min-height: 0;
}

.side {
  display: flex;
  flex-direction: column;
  gap: 8px;
  inline-size: 240px;
  padding: 12px;
  background: var(--panel);
  border-inline-end: 1px solid var(--line);
  overflow-y: auto;
}

.list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.list button {
  inline-size: 100%;
  margin-block-end: 4px;
  background: transparent;
  color: var(--text);
  text-align: start;
}

.list button[aria-current='true'] {
  background: var(--mine);
}

.chat {
  display: flex;
  flex: 1;
  flex-direction: column;
  min-width: 0;
  padding: 12px 16px;
}

.messages {
  flex: 1;
  margin: 0;
  padding: 0;
  overflow-y: auto;
  list-style: none;
}

.messages li {
  max-inline-size: 75%;
  margin-block: 6px;
  padding-block: 8px;
  padding-inline: 12px;
  border-radius: 10px;
  background: var(--panel);
  border: 1px solid var(--line);
  white-space: pre-wrap;
  overflow-wrap: anywhere;
  unicode-bidi: plaintext;
}

.messages li.user {
  margin-inline-start: auto;
  background: var(--mine);
}

.messages li.pending {
  color: var(--muted);
}

.composer {
  display: flex;
  gap: 8px;
  margin-block-start: 8px;
}

.composer textarea {
  flex: 1;
  padding: 8px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  color: var(--text);
  font: inherit;
  resize: vertical;
  unicode-bidi: plaintext;
}

.error {
  color: var(--error);
}

.muted {
  color: var(--muted);
}

.small {
  font-size: 13px;
}

@media (max-width: 700px) {
  .layout {
    flex-direction: column;
  }

  .side {
    inline-size: auto;
    max-block-size: 30vh;
    border-inline-end: 0;
    border-block-end: 1px solid var(--line);
  }

  .messages li {
    max-inline-size: 90%;
  }
}