:root {
  color-scheme: dark;
  --bg: #13161d;
  --panel: #1b2029;
  --panel-soft: #202632;
  --panel-border: #30394a;
  --text: #edf2ff;
  --muted: #99a3b8;
  --accent: #6aa4ff;
  --accent-strong: #8ab8ff;
  --danger: #ff7b7b;
  --shadow: 0 24px 60px rgba(0, 0, 0, 0.25);
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background:
    radial-gradient(circle at top, rgba(106, 164, 255, 0.14), transparent 35%),
    var(--bg);
  color: var(--text);
}

button,
input,
textarea {
  font: inherit;
}

.shell {
  display: grid;
  grid-template-columns: 320px 1fr;
  min-height: 100vh;
}

.sidebar {
  padding: 24px;
  border-right: 1px solid var(--panel-border);
  background: rgba(19, 22, 29, 0.9);
}

.sidebar__header,
.chat-app__header,
.composer__footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
}

.sidebar__header h1,
.chat-app__header h2 {
  margin: 0;
}

.status-pill {
  margin: 20px 0;
  display: inline-flex;
  align-items: center;
  padding: 8px 12px;
  border: 1px solid var(--panel-border);
  border-radius: 999px;
  color: var(--muted);
  background: var(--panel);
}

.conversation-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.conversation-button {
  width: 100%;
  padding: 14px 16px;
  border: 1px solid transparent;
  border-radius: 14px;
  text-align: left;
  background: transparent;
  color: var(--text);
  cursor: pointer;
  transition: background 160ms ease;
}

.conversation-button:hover,
.conversation-button.is-active {
  background: var(--panel-soft);
  border-color: var(--panel-border);
}

.chat-panel {
  display: flex;
  align-items: stretch;
  justify-content: center;
  padding: 32px;
}

.card,
.chat-app {
  width: min(960px, 100%);
  background: rgba(27, 32, 41, 0.9);
  border: 1px solid var(--panel-border);
  border-radius: 24px;
  box-shadow: var(--shadow);
}

.login-card {
  margin: auto;
  padding: 32px;
}

.chat-app {
  display: grid;
  grid-template-rows: auto 1fr auto;
  overflow: hidden;
}

.chat-app__header {
  padding: 24px;
  border-bottom: 1px solid var(--panel-border);
}

.eyebrow {
  margin: 0 0 6px;
  font-size: 0.8rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.message-list {
  display: flex;
  flex-direction: column;
  gap: 18px;
  padding: 24px;
  overflow-y: auto;
}

.message {
  max-width: min(80ch, 90%);
  padding: 16px 18px;
  border-radius: 18px;
  line-height: 1.5;
}

.message--user {
  align-self: flex-end;
  background: rgba(106, 164, 255, 0.14);
  border: 1px solid rgba(106, 164, 255, 0.3);
  white-space: pre-wrap;
}

.message--assistant {
  align-self: flex-start;
  background: var(--panel-soft);
  border: 1px solid var(--panel-border);
}

.message--assistant > :first-child {
  margin-top: 0;
}

.message--assistant > :last-child {
  margin-bottom: 0;
}

.message--assistant p,
.message--assistant ul,
.message--assistant ol,
.message--assistant pre,
.message--assistant blockquote {
  margin: 0 0 1em;
}

.message--assistant ul,
.message--assistant ol {
  padding-left: 1.5rem;
}

.message--assistant :not(pre) > code {
  padding: 0.15rem 0.4rem;
  border-radius: 0.45rem;
  background: rgba(255, 255, 255, 0.08);
  font-family:
    "SFMono-Regular", SFMono-Regular, ui-monospace, Menlo, Monaco, Consolas,
    "Liberation Mono", monospace;
  font-size: 0.92em;
}

.message--assistant pre {
  overflow-x: auto;
  padding: 14px 16px;
  border: 1px solid var(--panel-border);
  border-radius: 14px;
  background: #0f141d;
}

.message--assistant pre code {
  display: block;
  font-family:
    "SFMono-Regular", SFMono-Regular, ui-monospace, Menlo, Monaco, Consolas,
    "Liberation Mono", monospace;
  font-size: 0.92rem;
}

.message--assistant a {
  color: var(--accent-strong);
}

.message--assistant blockquote {
  padding-left: 1rem;
  border-left: 3px solid rgba(138, 184, 255, 0.45);
  color: var(--muted);
}

.message-status {
  margin: 0.85rem 0 0;
  font-size: 0.85rem;
  color: var(--muted);
}

.composer {
  padding: 24px;
  border-top: 1px solid var(--panel-border);
}

.composer textarea,
.stack input {
  width: 100%;
  padding: 14px 16px;
  margin-top: 8px;
  border: 1px solid var(--panel-border);
  border-radius: 14px;
  color: var(--text);
  background: #121722;
}

.composer textarea {
  resize: vertical;
  min-height: 88px;
}

.primary-button,
.ghost-button {
  padding: 10px 16px;
  border-radius: 999px;
  border: 1px solid var(--panel-border);
  cursor: pointer;
}

.primary-button {
  color: #08101f;
  background: linear-gradient(180deg, var(--accent-strong), var(--accent));
  border: none;
}

.ghost-button {
  background: transparent;
  color: var(--text);
}

.error-text {
  color: var(--danger);
  margin: 0;
}

.stack {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

@media (max-width: 960px) {
  .shell {
    grid-template-columns: 1fr;
  }

  .sidebar {
    border-right: none;
    border-bottom: 1px solid var(--panel-border);
  }

  .chat-panel {
    padding: 20px;
  }
}