:root {
  --bg: #0b1220;
  --panel: #0f172a;
  --muted: #94a3b8;
  --text: #e2e8f0;
  --primary: #60a5fa;
  --accent: #22d3ee;
  --border: #1f2937;
  --user: #1e3a8a;
  --assistant: #0b1220;
  --radius: 12px;
}

html, body {
  height: 100%;
}

body {
  margin: 0;
  background: radial-gradient(1200px 600px at 20% -10%, rgba(96,165,250,0.12), transparent 60%),
              radial-gradient(900px 600px at 100% 0%, rgba(34,211,238,0.12), transparent 50%),
              var(--bg);
  color: var(--text);
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Arial;
}

.container {
  max-width: 980px;
  margin: 0 auto;
  padding: 20px;
}

.card {
  background: linear-gradient(180deg, rgba(255,255,255,0.03), rgba(255,255,255,0.01));
  border: 1px solid var(--border);
  border-radius: var(--radius);
  backdrop-filter: blur(6px);
}

.title {
  font-size: 28px;
  font-weight: 700;
  letter-spacing: 0.2px;
  margin: 0 0 4px;
}

.subtitle {
  margin: 0 0 16px;
  color: var(--muted);
  font-size: 14px;
}

.toolbar {
  display: flex;
  gap: 12px;
  align-items: center;
  margin: 12px 0 16px;
}

.select {
  background: var(--panel);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 10px;
  padding: 8px 10px;
}

.chat {
  display: flex;
  flex-direction: column;
  gap: 10px;
  min-height: 60vh;
  max-height: 68vh;
  overflow: hidden;
}

.messages {
  flex: 1;
  overflow-y: auto;
  padding: 14px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  background: radial-gradient(800px 400px at 0% 0%, rgba(96,165,250,0.08), transparent 40%),
              radial-gradient(600px 400px at 100% 0%, rgba(34,211,238,0.06), transparent 40%),
              var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.msg {
  max-width: 78%;
  border: 1px solid var(--border);
  padding: 12px 14px;
  border-radius: 14px;
  line-height: 1.5;
  white-space: pre-wrap;
}

.msg .role {
  font-size: 11px;
  color: var(--muted);
  margin-bottom: 6px;
}

.msg.user {
  align-self: flex-end;
  background: linear-gradient(180deg, rgba(30,58,138,0.7), rgba(30,58,138,0.6));
}

.msg.assistant {
  align-self: flex-start;
  background: linear-gradient(180deg, rgba(2,6,23,0.9), rgba(2,6,23,0.8));
}

.msg.system {
  align-self: center;
  background: linear-gradient(180deg, rgba(120,53,15,0.25), rgba(120,53,15,0.18));
}

.composer {
  display: flex;
  gap: 10px;
  margin-top: 12px;
}

.input {
  flex: 1;
  background: var(--panel);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 12px;
  padding: 12px 14px;
  resize: none;
  min-height: 44px;
  max-height: 160px;
}

.button {
  background: linear-gradient(180deg, rgba(96,165,250,0.25), rgba(96,165,250,0.18));
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 0 16px;
  min-width: 84px;
  cursor: pointer;
}

.button.secondary {
  background: linear-gradient(180deg, rgba(34,211,238,0.22), rgba(34,211,238,0.16));
}

.footer {
  margin-top: 10px;
  color: var(--muted);
  font-size: 12px;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}