.mg-shell {
  box-sizing: border-box;
  width: min(1180px, 100% - 32px);
  margin-inline: auto;
}

.mg-workspace,
.mg-chat,
.mg-stage {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-paper);
}

.mg-workspace {
  padding: clamp(16px, 3vw, 32px);
}
.mg-chat {
  width: min(760px, 100% - 32px);
  min-height: min(780px, calc(100vh - 32px));
  margin: 16px auto;
}
.mg-stage {
  min-height: min(720px, calc(100vh - 32px));
  overflow: hidden;
}

.mg-shell__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 16px 20px;
  border-bottom: 1px solid var(--line);
}

.mg-shell__title {
  margin: 0;
  color: var(--ink);
  font-size: clamp(1.05rem, 2vw, 1.45rem);
}
.mg-shell__subtitle {
  margin: 4px 0 0;
  color: var(--ink-muted);
  font-size: 0.86rem;
}
.mg-reset {
  min-height: var(--touch-target);
  padding: 8px 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: var(--surface);
  color: var(--ink);
  cursor: pointer;
}

@media (max-width: 640px) {
  .mg-shell {
    width: min(100% - 20px, 1180px);
  }
  .mg-chat {
    width: min(100% - 20px, 760px);
    margin: 10px auto;
    min-height: calc(100vh - 20px);
  }
  .mg-shell__header {
    align-items: flex-start;
    flex-direction: column;
  }
}