*{margin:0;padding:0;box-sizing:border-box}:root{--yellow: #FFD93D;--pink: #FF6B9D;--blue: #4FC3F7;--green: #81C784;--orange: #FF8A65;--purple: #BA68C8;--bg: #FFF8E1;--card-bg: #FFFFFF;--text: #4A3728;--text-light: #8D6E63;--shadow: 0 4px 15px rgba(0,0,0,.08);--radius: 20px}body{font-family:PingFang SC,Microsoft YaHei,Noto Sans SC,sans-serif;background:var(--bg);color:var(--text);min-height:100vh;overflow-x:hidden;-webkit-user-select:none;user-select:none;-webkit-tap-highlight-color:transparent}.app{min-height:100vh;position:relative;max-width:500px;margin:0 auto;padding:20px}.stars-bg{position:fixed;top:0;left:0;width:100%;height:100%;pointer-events:none;z-index:0;overflow:hidden}.page-enter-active,.page-leave-active{transition:opacity .12s ease}.page-enter-from,.page-leave-to{opacity:0}.btn{padding:16px 24px;border:none;border-radius:var(--radius);font-size:18px;font-weight:700;cursor:pointer;transition:transform .15s;font-family:inherit;color:#fff}.btn:active{transform:scale(.96)}.btn-learn{background:linear-gradient(135deg,var(--blue),#29B6F6)}.btn-challenge{background:linear-gradient(135deg,var(--pink),#EC407A)}.btn-back{background:#fff;color:var(--text);border:2px solid #E0E0E0}.btn-purple{background:linear-gradient(135deg,var(--purple),#8E24AA)}.btn-green{background:linear-gradient(135deg,var(--green),#43A047)}.btn-orange{background:linear-gradient(135deg,var(--orange),#EF6C00)}