:root {
  --brand-blue: #2f53ff;
  --brand-blue-600: #2745d7;
  --card-bg: #ffffff;
  --text: #0f172a;
  --muted: #64748b;
  --border: #e2e8f0;
  --shadow: 0 10px 25px rgba(0, 0, 0, 0.08);
}

* { box-sizing: border-box; }
html, body, #root { height: 100%; }
body { 
  margin: 0; 
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, "Apple Color Emoji", "Segoe UI Emoji"; 
  color: var(--text); 
}

.app-shell { 
  display: flex; 
  min-height: 100vh; 
  flex-direction: column; 
  background: #fff; 
}

.app-main { 
  flex: 1 1 auto; 
  display: flex; 
  align-items: stretch; 
  justify-content: stretch; 
  width: 100%;
  overflow-x: hidden;
}

/* Navbar */
.nav {
  width: 100%;
  background: var(--brand-blue);
  display: flex; align-items: center; justify-content: space-between;
  padding: 14px 26px;
  color: #fff;
}
.brand { display: inline-flex; align-items: center; gap: 10px; font-weight: 700; color: #fff; text-decoration: none; }
.brand-logo { width: 28px; height: 28px; border-radius: 50%; background: #fff; display: inline-flex; align-items: center; justify-content: center; color: var(--brand-blue); font-size: 16px; }
.nav-actions { display: inline-flex; gap: 10px; }
.btn { appearance: none; border: 1px solid rgba(255,255,255,0.7); background: transparent; color: #fff; padding: 8px 16px; border-radius: 999px; cursor: pointer; font-weight: 600; text-decoration: none; }
.btn.primary { background: #fff; color: var(--brand-blue); border-color: #fff; }
.btn.primary:hover { background: #f1f4ff; }

/* Footer */
.footer { background: var(--brand-blue); color: #fff; padding: 16px 28px; display: grid; grid-template-columns: 1fr auto; gap: 12px; align-items: center; }
.footer .left { display: flex; align-items: center; gap: 10px; color: rgba(255,255,255,0.8); }
.footer .right { text-align: right; color: rgba(255,255,255,0.8); font-size: 14px; }

/* Centered card layout for auth */
.auth-wrap { flex: 1; display: flex; align-items: center; justify-content: center; padding: 60px 16px; background: #f6f7ff; }
.card { width: 100%; max-width: 520px; background: var(--card-bg); border-radius: 14px; box-shadow: var(--shadow); padding: 28px; }
.card h1 { text-align: center; margin: 0 0 18px; }
.field { display: grid; gap: 6px; margin-bottom: 12px; }
.field label { font-size: 14px; color: var(--muted); }
.input { width: 100%; padding: 12px 14px; border: 1px solid var(--border); border-radius: 10px; font-size: 16px; }
.input:focus { outline: none; border-color: var(--brand-blue); box-shadow: 0 0 0 3px rgba(47,83,255,0.15); }
.actions { margin-top: 14px; display: flex; gap: 10px; align-items: center; justify-content: center; }
.muted { color: var(--muted); font-size: 14px; }
.link { color: var(--brand-blue); text-decoration: none; font-weight: 600; }

.auth-card { background: var(--brand-blue); border-radius: 20px; color: #fff; }
.auth-card .field label { color: rgba(255,255,255,0.9); }
.auth-card .input { background: #fff; border: none; border-radius: 18px; color: #0f172a; box-shadow: inset 0 2px 4px rgba(0,0,0,0.1); }
.auth-card .input:focus { box-shadow: 0 0 0 3px rgba(255,255,255,0.35); }
.auth-card .muted { color: rgba(255,255,255,0.85); }
.auth-card .link { color: #fff; text-decoration: underline; }
.auth-card .btn.primary { background: transparent; border: 2px solid #fff; color: #fff; border-radius: 20px; padding: 8px 30px; width: 100%; }

/* Chat layout */
.chat-shell {
  display: grid;
  grid-template-columns: 260px 1fr;
  width: 100%;
  max-width: 1100px;
  margin: 40px auto;
  background: #fff;
  border-radius: 26px;
  border: 1px solid #dfe5ff;
  box-shadow: 0 24px 50px rgba(21, 40, 120, 0.15);
}
.sidebar { background: #f8fafc; border-right: 1px solid var(--border); padding: 22px; border-radius: 26px 0 0 26px; }
.sidebar h3 { margin-top: 0; }
.sidebar .menu { display: grid; gap: 10px; margin-top: 8px; }
.menu .item { display: flex; align-items: center; gap: 10px; padding: 10px 12px; border-radius: 10px; background: #fff; border: 1px solid var(--border); cursor: pointer; }

.chat-area {
  display: grid;
  grid-template-rows: 1fr auto;
  min-height: 520px;
  max-height: 520px;
  background: #eef2ff;
  border-radius: 0 26px 26px 0;
}
.chat-view { display: flex; flex-direction: column; gap: 12px; padding: 28px; overflow-y: auto; color: #0f172a; justify-content: flex-start; text-align: left; }
.chat-view .welcome { font-size: 20px; font-weight: 700; }

.composer { background: #fff; border-top: 1px solid var(--border); padding: 16px 24px; border-radius: 0 0 26px 0; }
.composer-inner { display: grid; grid-template-columns: 1fr auto; gap: 10px; max-width: 900px; margin: 0 auto; }
.composer .input { background: #fff; }

/* Chat bubble */
.bubble-row { display: flex; }
.bubble { max-width: 80%; padding: 12px 14px; border-radius: 18px; background: #fff; box-shadow: 0 14px 30px rgba(20, 34, 90, 0.12); color: var(--text); }
.bubble.user { margin-left: auto; background: #dee5ff; }
.bubble.bot { margin-right: auto; background: #fff; }

@media (max-width: 840px) {
  .chat-shell { grid-template-columns: 1fr; margin: 20px; }
  .sidebar { display: none; }
}