:root {
  --bg: #0f1117;
  --panel: #1a1d28;
  --panel-2: #232735;
  --accent: #6c8cff;
  --accent-2: #8a6cff;
  --text: #e6e8ef;
  --muted: #9aa0b4;
  --border: #2b3042;
  --ok: #3ecf8e;
  --err: #ff6b6b;
  --user: #2a3350;
}

* { box-sizing: border-box; }

/* The HTML [hidden] attribute must win over display:grid/flex layout rules. */
[hidden] { display: none !important; }

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
}

button { font-family: inherit; cursor: pointer; }

.primary {
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  color: #fff;
  border: none;
  border-radius: 10px;
  padding: 11px 22px;
  font-size: 15px;
  font-weight: 600;
}
.primary:disabled { opacity: 0.55; cursor: not-allowed; }

.ghost {
  background: transparent;
  color: var(--muted);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 7px 12px;
  font-size: 13px;
}

/* ---------- Login ---------- */
.login-overlay {
  position: fixed;
  inset: 0;
  display: grid;
  place-items: center;
  background: radial-gradient(1000px 500px at 50% -10%, #1b2030 0%, var(--bg) 60%);
}
.login-card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 40px;
  text-align: center;
  max-width: 380px;
}
.login-card h1 {
  margin: 0 0 8px;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent;
}
.subtitle { color: var(--muted); margin: 0 0 24px; }
.login-status { color: var(--err); font-size: 14px; margin-top: 16px; min-height: 18px; }

/* ---------- Layout ---------- */
.layout { display: grid; grid-template-columns: 280px 1fr; height: 100vh; }

.sidebar {
  background: var(--panel);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  padding: 16px;
  gap: 14px;
  overflow: hidden;
}
.new-chat { width: 100%; }
.conversation-list { flex: 1; overflow-y: auto; display: flex; flex-direction: column; gap: 6px; }
.conv-item {
  text-align: left;
  background: var(--panel-2);
  color: var(--text);
  border: 1px solid transparent;
  border-radius: 8px;
  padding: 10px 12px;
  font-size: 13px;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.conv-item:hover { border-color: var(--border); }
.conv-item.active { border-color: var(--accent); }
.sidebar-footer { border-top: 1px solid var(--border); padding-top: 12px; display: flex; flex-direction: column; gap: 8px; }
.user-email { font-size: 12px; color: var(--muted); word-break: break-all; }

.main { display: flex; flex-direction: column; height: 100vh; overflow: hidden; }
.topbar {
  display: flex; align-items: center; justify-content: space-between;
  padding: 16px 24px; border-bottom: 1px solid var(--border);
}
.topbar h1 {
  font-size: 18px; margin: 0;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent;
}
.model-select { display: flex; align-items: center; gap: 10px; }
.model-select label { color: var(--muted); font-size: 13px; }
select {
  background: var(--panel); color: var(--text);
  border: 1px solid var(--border); border-radius: 10px; padding: 9px 12px; font-size: 14px;
}
select:focus, textarea:focus { outline: 2px solid var(--accent); border-color: transparent; }

/* ---------- Thread ---------- */
.thread { flex: 1; overflow-y: auto; padding: 24px; display: flex; flex-direction: column; gap: 16px; }
.empty-state { color: var(--muted); text-align: center; margin-top: 40px; }

.bubble { max-width: 760px; border-radius: 14px; padding: 14px 16px; border: 1px solid var(--border); }
.bubble-user { background: var(--user); align-self: flex-end; }
.bubble-assistant { background: var(--panel); align-self: flex-start; }
.bubble-role { font-size: 11px; text-transform: uppercase; letter-spacing: 0.05em; color: var(--muted); margin-bottom: 6px; }
.bubble-text { white-space: pre-wrap; line-height: 1.6; font-size: 15px; }

.reasoning { margin-top: 10px; background: var(--panel-2); border: 1px solid var(--border); border-radius: 10px; padding: 8px 12px; }
.reasoning summary { cursor: pointer; color: var(--muted); font-size: 13px; }
.reasoning div { white-space: pre-wrap; margin-top: 8px; color: var(--muted); font-size: 13px; line-height: 1.5; }

.bubble-metrics { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 12px; padding-top: 12px; border-top: 1px solid var(--border); }
.bm { display: flex; flex-direction: column; background: var(--panel-2); border: 1px solid var(--border); border-radius: 8px; padding: 6px 10px; }
.bm-l { font-size: 10px; color: var(--muted); text-transform: uppercase; letter-spacing: 0.04em; }
.bm-v { font-size: 14px; font-weight: 700; }
.bubble-metrics .bm:last-child .bm-v { color: var(--ok); }

/* ---------- Prompt + status ---------- */
.status { margin: 0 24px; padding: 10px 14px; border-radius: 10px; font-size: 14px; background: var(--panel-2); border: 1px solid var(--border); }
.status-loading { color: var(--accent); }
.status-error { color: var(--err); border-color: var(--err); }

.prompt-form { display: flex; gap: 12px; padding: 16px 24px; border-top: 1px solid var(--border); align-items: flex-end; }
textarea {
  flex: 1; background: var(--panel); color: var(--text);
  border: 1px solid var(--border); border-radius: 12px; padding: 12px; font-size: 15px;
  resize: vertical; font-family: inherit; min-height: 48px;
}

@media (max-width: 720px) {
  .layout { grid-template-columns: 1fr; }
  .sidebar { display: none; }
}