/**
 * 系统名称：ITeacherPlatform
 * 开发公司：斯帝姆智能科技有限公司
 * 程序名：countdown.css
 * 功能描述：思维训练中心倒计时动画样式
 * 版本号：v1.0.0
 * 修订历史：
 *   - v1.0.0 (2026-05-31)：初始版本，实现3-2-1-GO倒计时动画效果
 */

/* 倒计时遮罩层 */
.countdown-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 99999;
    opacity: 0;
    /* 默认不拦截点击，避免倒计时结束后透明遮罩仍挡住游戏方格 */
    pointer-events: none;
    transition: opacity 0.3s ease;
}

.countdown-overlay.show {
    opacity: 1;
    /* 仅在倒计时显示期间拦截点击，让用户专注于倒计时 */
    pointer-events: auto;
}

/* 倒计时数字容器 */
.countdown-number {
    font-size: 150px;
    font-weight: bold;
    color: white;
    text-shadow: 0 0 30px rgba(255, 255, 255, 0.5);
    animation: countdownPulse 1s ease-out;
    user-select: none;
}

/* 倒计时数字动画 */
@keyframes countdownPulse {
    0% {
        transform: scale(0.5);
        opacity: 0;
    }
    50% {
        transform: scale(1.2);
        opacity: 1;
    }
    100% {
        transform: scale(1);
        opacity: 1;
    }
}

/* GO文字特殊样式 */
.countdown-number.go {
    color: #28a745;
    text-shadow: 0 0 50px rgba(40, 167, 69, 0.8);
    animation: countdownGo 0.8s ease-out;
}

@keyframes countdownGo {
    0% {
        transform: scale(0.3) rotate(-10deg);
        opacity: 0;
    }
    50% {
        transform: scale(1.3) rotate(5deg);
        opacity: 1;
    }
    100% {
        transform: scale(1) rotate(0deg);
        opacity: 1;
    }
}

/* 倒计时淡出动画 */
.countdown-overlay.fade-out {
    opacity: 0;
    transition: opacity 0.5s ease;
}

/* 响应式调整 */
@media (max-width: 768px) {
    .countdown-number {
        font-size: 100px;
    }
}