:root {
  color-scheme: dark;
  --bg: #090b11;
  --panel: rgba(19, 23, 36, 0.84);
  --panel-border: rgba(255, 255, 255, 0.08);
  --text: #f2f6ff;
  --muted: #8d98af;
  --accent: linear-gradient(130deg, #7ee8fa 0%, #81a4fd 50%, #d085ff 100%);
  --bubble: rgba(255, 255, 255, 0.04);
}

* { box-sizing: border-box; }
html, body { height: 100%; margin: 0; font-family: Inter, sans-serif; color: var(--text); background: var(--bg); }

.bg {
  position: fixed;
  inset: 0;
  background:
    radial-gradient(circle at 10% 5%, rgba(101, 80, 255, 0.2), transparent 40%),
    radial-gradient(circle at 80% 10%, rgba(2, 202, 255, 0.18), transparent 30%),
    radial-gradient(circle at 50% 80%, rgba(180, 60, 255, 0.18), transparent 45%);
  pointer-events: none;
}

.app { display: grid; grid-template-columns: 280px 1fr; height: 100%; position: relative; }

.sidebar {
  backdrop-filter: blur(20px);
  background: var(--panel);
  border-right: 1px solid var(--panel-border);
  padding: 1rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.logo-wrap { display: flex; gap: .75rem; align-items: center; }
.logo { width: 42px; height: 42px; border-radius: 12px; display: grid; place-items: center; background: var(--accent); color: #0d1020; font-weight: 800; }
.logo-wrap h1 { margin: 0; font-size: 1.1rem; }
.logo-wrap p { margin: 0; color: var(--muted); font-size: .8rem; }

.new-chat, .auth-btn, .mode-btn, #send-btn, .auth-grid button {
  border: 1px solid var(--panel-border);
  background: rgba(255, 255, 255, 0.05);
  color: var(--text);
  border-radius: 12px;
  padding: .72rem .9rem;
  cursor: pointer;
}
.new-chat:hover, .auth-btn:hover, .mode-btn:hover, #send-btn:hover, .auth-grid button:hover { background: rgba(255,255,255,.1); }

.history-block { flex: 1; overflow-y: auto; }
.history-block h2 { margin: 0 0 .6rem; color: var(--muted); font-size: .84rem; }
#history-list { list-style: none; margin: 0; padding: 0; display: grid; gap: .5rem; }
#history-list li { background: var(--bubble); border: 1px solid var(--panel-border); padding: .6rem .7rem; border-radius: 10px; font-size: .86rem; color: #d3dcf0; }

.main { display: grid; grid-template-rows: auto 1fr auto; height: 100%; }
.topbar { padding: 1rem; border-bottom: 1px solid var(--panel-border); }
.mode-group { display: inline-flex; gap: .5rem; padding: .3rem; border: 1px solid var(--panel-border); border-radius: 14px; background: rgba(8, 11, 20, .65); }
.mode-btn.active { background: var(--accent); color: #0d1020; border-color: transparent; font-weight: 700; }

.chat { padding: 1.2rem; overflow-y: auto; display: flex; flex-direction: column; gap: .8rem; }
.message { max-width: min(860px, 90%); padding: .9rem 1rem; border-radius: 15px; border: 1px solid var(--panel-border); line-height: 1.5; white-space: pre-wrap; }
.message.user { align-self: flex-end; background: rgba(126, 232, 250, .1); }
.message.assistant { align-self: flex-start; background: rgba(255, 255, 255, .03); }
.reasoning { margin-top: .65rem; border-top: 1px dashed var(--panel-border); padding-top: .65rem; }
.reasoning summary { cursor: pointer; color: #9ad5ff; }
.reasoning pre { margin: .45rem 0 0; white-space: pre-wrap; color: #b9c5df; font-size: .82rem; }

.composer { padding: 1rem; border-top: 1px solid var(--panel-border); display: grid; grid-template-columns: 1fr auto; gap: .7rem; }
#prompt {
  resize: none;
  border-radius: 14px;
  border: 1px solid var(--panel-border);
  background: rgba(12, 16, 27, .95);
  color: var(--text);
  padding: .9rem 1rem;
  font: inherit;
  min-height: 50px;
  max-height: 180px;
}

.auth-modal {
  width: min(440px, 90vw);
  border: 1px solid var(--panel-border);
  border-radius: 16px;
  background: #121726;
  color: var(--text);
  padding: 1.2rem;
}
.auth-grid { display: grid; grid-template-columns: 1fr 1fr; gap: .7rem; margin: 1rem 0; }
.ghost { width: 100%; background: transparent; border: 1px solid var(--panel-border); border-radius: 10px; color: var(--text); padding: .6rem; }

@media (max-width: 980px) {
  .app { grid-template-columns: 1fr; }
  .sidebar { display: none; }
}