* { box-sizing: border-box; }
html { touch-action: manipulation; }
body { margin: 0; font-family: -apple-system, sans-serif; background: #f4f7fb; color: #222; }
#app { max-width: 820px; margin: 0 auto; padding: 24px; text-align: center; }
h1 { font-size: 2rem; }
h2 { font-size: 1.7rem; }
button { font-family: inherit; cursor: pointer; -webkit-tap-highlight-color: transparent; }
button:active { transform: scale(0.97); }
.row { display: flex; flex-wrap: wrap; gap: 16px; justify-content: center; }
.kid { font-size: 1.6rem; min-width: 170px; min-height: 100px; border: 0; border-radius: 18px;
  background: #4a7cf7; color: #fff; }
.kid small { display: block; font-size: 1rem; opacity: 0.85; margin-top: 4px; }
.kid:disabled { opacity: 0.5; }
.lv { font-size: 1.6rem; min-width: 200px; min-height: 130px; border: 0; border-radius: 20px; color: #fff; }
.lv small { display: block; font-size: 1rem; margin-top: 6px; }
.lv.easy { background: #2bb673; }
.lv.normal { background: #ff9f1c; }
.lv.hard { background: #e5484d; }
.topbar { display: flex; align-items: center; justify-content: space-between; gap: 12px; flex-wrap: wrap; }
.back { font-size: 1.1rem; min-height: 52px; padding: 0 18px; border: 0; border-radius: 12px; background: #dde3ee; }
.who { font-size: 1.5rem; font-weight: bold; }
select { font-size: 1.2rem; min-height: 52px; padding: 0 14px; border-radius: 12px; border: 2px solid #4a7cf7; background: #fff; }
.game { margin-top: 32px; padding: 60px 20px; border-radius: 20px; background: #fff; font-size: 1.6rem;
  box-shadow: 0 4px 16px rgba(0,0,0,0.08); }
.msg { color: #d33; font-size: 1.1rem; margin-top: 20px; }