:root {
  --paper: #fbfafc;
  --ink: #21182d;
  --muted: #73677f;
  --focus: #765dc9;
  --font: "Segoe UI", "PingFang TC", "Noto Sans TC", "Microsoft JhengHei", sans-serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html,
body {
  width: 100%;
  min-width: 0;
  height: 100%;
}

body {
  margin: 0;
  overflow: hidden;
  color: var(--ink);
  background: var(--paper);
  font-family: var(--font);
  -webkit-font-smoothing: antialiased;
}

.brand {
  position: fixed;
  top: clamp(1rem, 3vw, 2rem);
  left: clamp(1rem, 3vw, 2rem);
  z-index: 2;
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  pointer-events: none;
  user-select: none;
}

.brand img {
  width: clamp(2.5rem, 5vw, 3rem);
  height: clamp(2.5rem, 5vw, 3rem);
  border: 1px solid rgba(33, 24, 45, 0.1);
  border-radius: 0.9rem;
  background: #eee9f5;
  box-shadow: 0 0.6rem 1.8rem rgba(54, 39, 78, 0.1);
  object-fit: cover;
}

.brand h1 {
  margin: 0;
  font-size: clamp(1rem, 2.5vw, 1.25rem);
  font-weight: 720;
  letter-spacing: 0.08em;
}

main,
#world {
  width: 100%;
  height: 100%;
}

#world {
  display: block;
  outline: 0;
  touch-action: manipulation;
}

#world:focus-visible {
  box-shadow: inset 0 0 0 3px color-mix(in srgb, var(--focus) 74%, transparent);
}

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

@media (max-width: 520px) {
  .brand {
    gap: 0.6rem;
  }

  .brand img {
    border-radius: 0.75rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  #world {
    cursor: pointer;
  }
}