/* ============================================================
   FishRain · Ocean Extras
   交互增强层：滚动渐入 / 回到顶部
   由 js/pixel-effects.js 驱动，仅包含 JS 动态创建的元素样式
   （极简化修订：移除点击粒子与鱼雨彩蛋相关样式）
   ============================================================ */

/* ---------- 滚动渐入（平滑淡入上移） ---------- */
.pixel-reveal {
    opacity: 1;
}

html.js-anim .pixel-reveal {
    opacity: 0;
    transform: translateY(22px);
    transition: opacity 0.55s ease, transform 0.55s ease;
    will-change: opacity, transform;
}

html.js-anim .pixel-reveal.in-view {
    opacity: 1;
    transform: translateY(0);
}

/* ---------- 回到顶部（中性箭头图标） ---------- */
.back-to-top {
    position: fixed;
    bottom: 28px;
    right: 28px;
    width: 46px;
    height: 46px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 50%;
    cursor: pointer;
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
    transform: translateY(14px);
    transition: opacity 0.3s ease, transform 0.3s ease, visibility 0.3s ease, border-color 0.2s ease, box-shadow 0.2s ease;
    box-shadow: var(--shadow-md);
}

.back-to-top::before {
    content: '↑';
    font-size: 20px;
    font-weight: 700;
    line-height: 1;
    color: var(--text-secondary);
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    border-color: var(--ocean-soft);
    transform: translateY(-3px);
    box-shadow: var(--shadow-hover);
}

.back-to-top:hover::before {
    color: var(--ocean-soft);
}

/* ---------- 减少动画偏好 ---------- */
@media (prefers-reduced-motion: reduce) {
    html.js-anim .pixel-reveal {
        opacity: 1;
        transform: none;
        transition: none;
    }
}