:root {
  --surface: #ffffff;
  --surface-elevated: #ffffff;
  --sidebar: #eceff3;
  --line: #d9dee6;
  --text: #111827;
  --muted: #5f6978;
  --link: #0f4c81;
  --input-bg: #ffffff;
  --body-grad-start: #f9fafb;
  --body-grad-end: #f1f4f8;
  --accent: #202938;
  --accent-hover: #131a26;
  --secondary: #4b5565;
  --assistant: #f8fafc;
  --user: #e9f2ff;
  --error: #ffe9e9;
  --error-text: #b42318;
}

body[data-theme="dark"] {
  --surface: #121926;
  --surface-elevated: #0f1722;
  --sidebar: #1a2232;
  --line: #2a3548;
  --text: #e5ecf5;
  --muted: #a4b1c4;
  --link: #8ebdff;
  --input-bg: #101827;
  --body-grad-start: #0b111b;
  --body-grad-end: #0a0f18;
  --accent: #6c8fd8;
  --accent-hover: #5b7cc0;
  --secondary: #35455f;
  --assistant: #131d2c;
  --user: #1d2b43;
  --error: #3a1e24;
  --error-text: #ffb7b7;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: "Space Grotesk", sans-serif;
  color: var(--text);
  background: linear-gradient(180deg, var(--body-grad-start) 0%, var(--body-grad-end) 100%);
}

.layout {
  min-height: 100vh;
  display: grid;
  grid-template-columns: 300px 1fr;
  max-width: 1440px;
  margin: 0 auto;
}

.sidebar {
  background: var(--sidebar);
  border-right: 1px solid var(--line);
  padding: 26px 20px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  box-shadow: inset -1px 0 0 rgba(255, 255, 255, 0.06);
}

.brand {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: 0.01em;
}

.sidebar-copy {
  margin: 0;
  color: var(--muted);
  line-height: 1.5;
  font-size: 0.95rem;
}

.nav-link {
  display: inline-block;
  margin-top: 6px;
  color: var(--link);
  text-decoration: none;
  font-weight: 600;
}

label {
  margin-top: 8px;
  margin-bottom: 4px;
  font-size: 0.88rem;
  font-weight: 600;
}

input,
textarea {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 10px 12px;
  font: inherit;
  background: var(--input-bg);
  color: var(--text);
}

input:focus,
textarea:focus {
  outline: 2px solid rgba(108, 143, 216, 0.45);
  outline-offset: 1px;
}

textarea {
  resize: vertical;
}

button {
  margin-top: 10px;
  border: 0;
  border-radius: 10px;
  padding: 10px 14px;
  font: inherit;
  font-weight: 700;
  cursor: pointer;
  background: var(--accent);
  color: #fff;
  transition: transform 120ms ease, box-shadow 150ms ease, background 150ms ease;
}

button:hover {
  background: var(--accent-hover);
  transform: translateY(-1px);
  box-shadow: 0 8px 18px rgba(0, 0, 0, 0.14);
}

button:active {
  transform: translateY(0);
}

button.secondary {
  background: var(--secondary);
}

.status-line {
  margin: 8px 0 0;
  color: var(--muted);
  font-size: 0.88rem;
}

.status-line.error {
  color: var(--error-text);
}

hr {
  border: 0;
  border-top: 1px solid var(--line);
  margin: 14px 0;
}

.workspace {
  display: flex;
  flex-direction: column;
  max-height: 100vh;
}

.workspace-header {
  padding: 20px 24px;
  border-bottom: 1px solid var(--line);
  background: var(--surface);
  display: flex;
  align-items: center;
  justify-content: space-between;
  backdrop-filter: blur(4px);
}

.workspace-header h1 {
  margin: 0;
  font-size: 1.1rem;
  font-weight: 700;
}

.workspace-header h1:empty {
  display: none;
}

.status-chip {
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.72rem;
  padding: 4px 8px;
  border-radius: 999px;
  border: 1px solid var(--line);
  color: var(--muted);
  background: var(--surface-elevated);
}

.chat-messages {
  flex: 1;
  overflow: auto;
  padding: 28px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.msg {
  max-width: min(780px, 92%);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 12px 14px;
  animation: in 180ms ease;
  box-shadow: 0 6px 18px rgba(0, 0, 0, 0.04);
}

.msg.bot {
  background: var(--assistant);
  align-self: flex-start;
}

.msg.user {
  background: var(--user);
  align-self: flex-end;
}

.msg.error {
  background: var(--error);
  border-color: #f8b4b4;
  align-self: flex-start;
}

.msg.welcome {
  align-self: center;
  margin: auto;
  background: transparent;
  border: 0;
  color: var(--text);
  font-size: clamp(1.35rem, 2.2vw, 1.8rem);
  font-weight: 700;
  letter-spacing: 0.01em;
  text-align: center;
  text-shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
  box-shadow: none;
}

.msg.welcome .msg-role {
  display: none;
}

.msg-role {
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.7rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 6px;
}

.msg-body {
  line-height: 1.5;
  white-space: pre-wrap;
}

.sources {
  margin-top: 8px;
  font-size: 0.82rem;
  color: var(--muted);
}

.composer {
  border-top: 1px solid var(--line);
  background: var(--surface);
  padding: 14px 18px;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 10px;
  box-shadow: 0 -6px 20px rgba(0, 0, 0, 0.06);
}

.composer input {
  border-radius: 12px;
}

.composer button {
  margin-top: 0;
  border-radius: 12px;
}

@keyframes in {
  from {
    transform: translateY(8px);
    opacity: 0;
  }

  to {
    transform: translateY(0);
    opacity: 1;
  }
}

@media (max-width: 980px) {
  .layout {
    grid-template-columns: 1fr;
  }

  .sidebar {
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  .chat-messages {
    min-height: 54vh;
    padding: 18px;
  }
}

.auth-dialog {
  border: 0;
  padding: 0;
  border-radius: 16px;
  width: min(420px, calc(100vw - 32px));
}

.auth-dialog::backdrop {
  background: rgba(17, 24, 39, 0.5);
  backdrop-filter: blur(2px);
}

.auth-card {
  margin: 0;
  padding: 18px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  background: var(--surface);
  color: var(--text);
}

.auth-card h2 {
  margin: 0;
  font-size: 1.1rem;
}

.auth-card p {
  margin: 0;
  color: var(--muted);
  font-size: 0.9rem;
}

.auth-actions {
  display: flex;
  gap: 10px;
  justify-content: flex-end;
}

.auth-actions button {
  margin-top: 0;
}

.theme-toggle {
  width: 100%;
}