/*
 * 下雨动画公共样式：站点内所有下雨场景共用这一份定义。
 * 动画参数（雨柱位置/长度/时长、落点爆炸）在 /static/site/rain.js 里，
 * 两个文件都不要单独改，保证各页面完全一致。
 */
:root {
  --rain-top: #ffffff;
  --rain-bottom: #f5f5f5;
  --rain-floor: #f5f5f5;
}

[data-theme="dark"] {
  --rain-top: #0a0a0a;
  --rain-bottom: #262626;
  --rain-floor: #f5f5f5;
}

.rain-scene {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  background: linear-gradient(to bottom, var(--rain-top), var(--rain-bottom));
}

/* 内容页用法：整屏固定一层雨幕，页面内容压在它上面。 */
.rain-scene--fixed {
  position: fixed;
  inset: 0;
  z-index: 0;
  height: 100%;
  pointer-events: none;
}

.rain-layer {
  position: absolute;
  inset: 0;
  z-index: 0;
  overflow: hidden;
  pointer-events: none;
}

.rain-floor {
  position: absolute;
  right: 0;
  bottom: 0;
  left: 0;
  z-index: 2;
  height: 0;
  background: var(--rain-floor);
  pointer-events: none;
  box-shadow:
    0 0 24px rgba(34, 42, 53, 0.06),
    0 1px 1px rgba(0, 0, 0, 0.05),
    0 0 0 1px rgba(34, 42, 53, 0.04),
    0 0 4px rgba(34, 42, 53, 0.08),
    0 16px 68px rgba(47, 48, 55, 0.05),
    0 1px 0 rgba(255, 255, 255, 0.1) inset;
}

.rain-beam {
  position: absolute;
  top: 5rem;
  left: 0;
  width: 1px;
  height: 3.5rem;
  border-radius: 9999px;
  background: linear-gradient(to top, #6366f1, #a855f7, transparent);
  pointer-events: none;
  will-change: transform;
}

.rain-beam--h6 {
  height: 1.5rem;
}

.rain-beam--h12 {
  height: 3rem;
}

.rain-beam--h20 {
  height: 5rem;
}

.rain-explosion {
  position: absolute;
  z-index: 4;
  width: 0.5rem;
  height: 0.5rem;
  transform: translate(-50%, -50%);
  pointer-events: none;
  animation: rain-explosion-fade 3.5s both;
}

.rain-explosion-flash {
  position: absolute;
  top: 0;
  left: 50%;
  width: 2.5rem;
  height: 0.5rem;
  border-radius: 9999px;
  background: linear-gradient(to right, transparent, #6366f1, transparent);
  filter: blur(4px);
  transform: translateX(-50%);
}

.rain-explosion-particle {
  position: absolute;
  width: 0.25rem;
  height: 0.25rem;
  border-radius: 50%;
  background: linear-gradient(to bottom, #6366f1, #a855f7);
  animation-name: rain-particle;
  animation-timing-function: ease-out;
  animation-fill-mode: both;
}

@keyframes rain-explosion-fade {
  0% {
    opacity: 0;
    animation-timing-function: ease-out;
  }

  42.86% {
    opacity: 1;
    animation-timing-function: linear;
  }

  57.14% {
    opacity: 1;
    animation-timing-function: ease-out;
  }

  100% {
    opacity: 0;
  }
}

@keyframes rain-particle {
  0% {
    opacity: 1;
    transform: translate(0, 0);
  }

  100% {
    opacity: 0;
    transform: translate(var(--particle-x), var(--particle-y));
  }
}