:root {
  --bg: #f6f7f9;
  --panel: #ffffff;
  --text: #172033;
  --muted: #667085;
  --line: #d9dee7;
  --brand: #246bfe;
  --brand-dark: #174ec0;
  --ok: #16803c;
  --warn: #b45f00;
  --danger: #c33131;
  --disabled: #a7afbf;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: Arial, "Microsoft YaHei", sans-serif;
}

button, input, textarea, select {
  font: inherit;
}

button {
  border: 0;
  border-radius: 6px;
  background: var(--brand);
  color: #fff;
  padding: 10px 14px;
  cursor: pointer;
}

button:hover {
  background: var(--brand-dark);
}

button.secondary {
  background: #eef2f8;
  color: var(--text);
}

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

button:disabled {
  background: var(--disabled);
  cursor: not-allowed;
}

.app-shell {
  min-height: 100vh;
  display: grid;
  grid-template-rows: auto 1fr;
}

.topbar {
  background: var(--panel);
  border-bottom: 1px solid var(--line);
  padding: 14px 22px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.topbar h1 {
  margin: 0;
  font-size: 20px;
}

.layout {
  width: min(1280px, calc(100% - 32px));
  margin: 18px auto;
  display: grid;
  grid-template-columns: 340px 1fr;
  gap: 16px;
}

.auth-layout {
  width: min(1120px, calc(100% - 32px));
  margin: 18px auto;
  display: grid;
  grid-template-columns: minmax(280px, 420px) 1fr;
  gap: 16px;
}

.panel {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 16px;
}

.panel h2, .panel h3 {
  margin: 0 0 12px;
}

.form-grid {
  display: grid;
  gap: 10px;
}

label {
  display: grid;
  gap: 6px;
  color: var(--muted);
  font-size: 13px;
}

input, textarea, select {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 10px;
  color: var(--text);
  background: #fff;
}

.row {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.status {
  color: var(--muted);
  font-size: 13px;
}

.badge {
  border-radius: 999px;
  padding: 4px 9px;
  font-size: 12px;
  background: #eef2f8;
  color: var(--muted);
}

.badge.ok {
  background: #e7f7ed;
  color: var(--ok);
}

.badge.warn {
  background: #fff4e5;
  color: var(--warn);
}

.chat-area {
  min-height: 640px;
  display: grid;
  grid-template-rows: auto 1fr auto;
  gap: 12px;
}

.messages {
  border: 1px solid var(--line);
  border-radius: 8px;
  min-height: 360px;
  max-height: 52vh;
  overflow: auto;
  padding: 12px;
  background: #fbfcfe;
}

.message {
  margin-bottom: 10px;
  display: grid;
  gap: 4px;
}

.message .meta {
  color: var(--muted);
  font-size: 12px;
}

.message .bubble {
  width: fit-content;
  max-width: min(680px, 92%);
  border-radius: 8px;
  padding: 9px 11px;
  background: #eef2f8;
  white-space: pre-wrap;
  overflow-wrap: anywhere;
}

.message.me {
  justify-items: end;
}

.message.me .bubble {
  background: #dfe9ff;
}

.composer {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 10px;
}

.features {
  display: grid;
  grid-template-columns: repeat(3, minmax(150px, 1fr));
  gap: 10px;
}

.rate-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(180px, 1fr));
  gap: 10px;
}

.rate-line {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 10px;
  display: flex;
  justify-content: space-between;
  gap: 12px;
}

.feature-card {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px;
  display: grid;
  gap: 10px;
}

.feature-card.disabled {
  opacity: .55;
}

.video-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(180px, 1fr));
  gap: 10px;
}

video {
  width: 100%;
  aspect-ratio: 16 / 10;
  background: #101828;
  border-radius: 8px;
}

.qr {
  width: 180px;
  max-width: 100%;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 8px;
  background: #fff;
}

.modal-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(20, 27, 43, .42);
  display: none;
  place-items: center;
  padding: 20px;
}

.modal-backdrop.open {
  display: grid;
}

.modal {
  background: #fff;
  border-radius: 8px;
  width: min(420px, 100%);
  padding: 18px;
  display: grid;
  gap: 12px;
}

@media (max-width: 860px) {
  .layout, .auth-layout {
    grid-template-columns: 1fr;
  }

  .features, .video-grid, .rate-grid {
    grid-template-columns: 1fr;
  }

  .topbar {
    align-items: flex-start;
    flex-direction: column;
  }
}