/* 全屏背景渐变效果 */
body {
    background: linear-gradient(to bottom, #000000, #333333);
    margin: 0;
    padding: 0;
    height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    color: white;
    font-family: Arial, sans-serif;
    overflow: hidden;
}

/* 倒计时时钟样式 */
#countdown-label {
    /* 字体大小再增大一倍 */
    font-size: 84px;
    opacity: 0;
    animation: fade-in 2s forwards;
    /* 使用「站酷快乐体」中文艺术字体 */
    font-family: 'ZCOOL KuaiLe', cursive;
    /* 渐变文字效果 */
    background: linear-gradient(45deg, #ff6b6b, #4ecdc4, #45b7d1, #96ceb4, #ffd166, #ef476f, #06d6a0);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    /* 文字阴影增强立体感 */
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
}

#countdown {
    font-size: 48px;
}

/* 祝福语句动画效果 */
#message {
    opacity: 0;
    animation: fade-in 2s forwards;
    font-family: 'Satisfy', cursive;
    font-size: 84px;
    margin-top: 15px;
    /* 彩虹渐变背景 */
    background: linear-gradient(45deg, #FF0000, #FF7F00, #FFFF00, #00FF00, #0000FF, #4B0082, #8B00FF);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
}

@keyframes fade-in {
    0% {
        opacity: 0;
    }
    100% {
        opacity: 1;
    }
}

/* 输入框和按钮样式 */
#input-box {
    margin-top: 20px;
}

#calculate-btn {
    margin-top: 10px;
    padding: 5px 10px;
}

/* 下雪背景效果 */
#snow-container {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: -1;
}

.snowflake {
    position: absolute;
    width: 10px;
    height: 10px;
    border-radius: 50%;
    opacity: 0.8;
    pointer-events: none;
    animation: snowfall linear infinite;
}

@keyframes snowfall {
    0% {
        transform: translateY(-100%);
    }
    100% {
        transform: translateY(100vh);
    }
}