/* 动态星空背景 */
body {
    background: linear-gradient(135deg, #0f0c29, #302b63, #24243e);
    background-size: 400% 400%;
    animation: gradientBG 15s ease infinite;
    font-family: 'PingFang SC', 'Microsoft YaHei', sans-serif;
    overflow: hidden; 
    color: white;
}
@keyframes gradientBG {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}
/* 玻璃拟态卡片 */
.glass-card {
    background: rgba(255, 255, 255, 0.08);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid rgba(255, 255, 255, 0.15);
    box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
}
.option-active:active {
    background: rgba(255, 255, 255, 0.25);
    transform: scale(0.98);
}
/* 粒子 */
.star {
    position: absolute;
    background: white;
    border-radius: 50%;
    animation: twinkle 3s infinite ease-in-out;
}
@keyframes twinkle {
    0%, 100% { opacity: 0.2; transform: scale(0.8); }
    50% { opacity: 0.8; transform: scale(1.2); }
}
.hide-scrollbar::-webkit-scrollbar { display: none; }
.hide-scrollbar { -ms-overflow-style: none; scrollbar-width: none; }