:root {
  color-scheme: light;
  font-family: "Microsoft YaHei UI", "PingFang SC", system-ui, sans-serif;
  background: #183b42;
}

* { box-sizing: border-box; }

html, body {
  width: 100%;
  min-height: 100%;
  margin: 0;
  overflow: hidden;
  overscroll-behavior: none;
  touch-action: none;
}

body {
  display: grid;
  place-items: center;
  background:
    radial-gradient(circle at 50% 18%, rgba(252, 196, 118, .22), transparent 36%),
    linear-gradient(145deg, #17373d, #294f57 52%, #16343a);
}

.app-shell {
  position: relative;
  width: min(100vw, calc(100vh * 390 / 844));
  height: min(100vh, calc(100vw * 844 / 390));
  overflow: hidden;
  background: #f6e2bd;
  box-shadow: 0 24px 80px rgba(0, 0, 0, .45);
}

canvas {
  display: block;
  width: 100%;
  height: 100%;
  touch-action: none;
}

.loading-card {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 10px;
  color: #fff9ec;
  text-align: center;
  background: linear-gradient(180deg, #e99070, #d96f5d);
  transition: opacity .35s ease, visibility .35s ease;
}

.loading-card.hidden { opacity: 0; visibility: hidden; }
.loading-card strong { font-size: 24px; letter-spacing: 2px; }
.loading-card small { opacity: .88; }

.loading-mark {
  width: 72px;
  height: 72px;
  border: 8px solid rgba(255,255,255,.25);
  border-top-color: #fff4cf;
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

@keyframes spin { to { transform: rotate(360deg); } }

@media (min-width: 700px) {
  .app-shell { border-radius: 22px; }
}