* {
  box-sizing: border-box;
}

:root {
  --gap: 2px;
  --radius: 8px;
}

body {
  margin: 0;
  font-family: STSong, TW-Sung;
}

a {
  text-decoration: none !important;
  color: #FFF;
}

/* 浮动圆圈背景 */
.bg-circles {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: -1;
  pointer-events: none;
}

/* 轮播背景样式 */
.bg-slider {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  z-index: -2;
  overflow: hidden;
  /* iOS Safari 修复 */
  min-height: -webkit-fill-available;
}

.bg-slide {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
  opacity: 0;
  transition: opacity 1s ease-in-out;
}

.bg-slide.active {
  opacity: 1;
}

.grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--gap);
  padding: var(--gap);
  height: 100vh;
  position: relative;
  display: -ms-grid;
  -ms-grid-columns: 1fr [4];
}
.grid div {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  justify-content: flex-end;
  padding: calc(var(--gap) * 1.5);
  min-height: 160px;
  color: #fff;
  font-size: 20px;
  font-weight: 600;
  background-color: rgba(0, 0, 0, 0.2);
  background-attachment: fixed;
  background-size: cover;
  background-position: center;
  position: relative;
  cursor: pointer;
  overflow: hidden;
  border-radius: var(--radius);
  transition-property: filter, backdrop-filter, opacity, color, border-radius, box-shadow;
  transition-duration: 0.3s;
  transition-timing-function: ease-out;
  display: -webkit-box;
  display: -ms-flexbox;
  -webkit-box-orient: vertical;
  -webkit-box-direction: normal;
  -ms-flex-direction: column;
  -webkit-box-align: start;
  -ms-flex-align: start;
  -webkit-box-pack: end;
  -ms-flex-pack: end;
  -webkit-transition-property: opacity, color, -webkit-filter, -webkit-backdrop-filter;
  transition-property: opacity, color, -webkit-filter, -webkit-backdrop-filter;
  -webkit-transition-duration: 0.3s;
  -webkit-transition-timing-function: ease-out;
}

/* hover 背景切换层 */
.grid div .hover-bg {
  position: absolute;
  inset: 0;
  background-attachment: fixed;
  background-size: cover;
  background-position: center;
  opacity: 0;
  transition: opacity 0.2s ease-out;
  z-index: -1;
  border-radius: inherit;
}

.grid div:hover .hover-bg {
  opacity: 1;
}

/* 磨砂颗粒纹理层 */
.grid div::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)' opacity='0.4'/%3E%3C/svg%3E");
  background-size: 128px 128px;
  mix-blend-mode: overlay;
  opacity: 0.15;
  z-index: 0;
  pointer-events: none;
  border-radius: inherit;
  transition: opacity 0.15s;
}

/* 磨砂玻璃光泽层 */
.grid div::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(
    135deg,
    rgba(255, 255, 255, 0.06) 0%,
    transparent 40%,
    transparent 60%,
    rgba(255, 255, 255, 0.02) 100%
  );
  z-index: 0;
  pointer-events: none;
  border-radius: inherit;
}

.grid div:hover::before {
  opacity: 0.25;
}
.grid div:hover {
  color: #fff;
}
.grid div span:first-of-type {
  z-index: 3;
  position: relative;
}
.grid div .overlay {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  opacity: 0;
  background: linear-gradient(180deg, rgba(0, 0, 0, 0) 5%, rgba(0, 0, 0, 0.8));
  backdrop-filter: blur(6px);
  transition-property: opacity;
  transition-duration: 0.2s;
  transition-timing-function: ease-out;
  z-index: 2;
  background: -webkit-linear-gradient(top, rgba(0, 0, 0, 0) 5%, rgba(0, 0, 0, 0.8));
  -webkit-backdrop-filter: blur(6px);
  -webkit-transition-property: opacity;
  -webkit-transition-duration: 0.2s;
  -webkit-transition-timing-function: ease-out;
}
.grid div .show {
  display: block;
  color: tomato;
  font-size: 16px;
  font-weight: 400;
  margin-top: 8px;
  margin-bottom: -25px;
  opacity: 0;
  transition-property: margin-bottom, opacity;
  transition-duration: 0.15s;
  transition-timing-function: ease-out;
  z-index: 3;
  position: relative;
  -webkit-transition-property: margin-bottom, opacity;
  -webkit-transition-duration: 0.15s;
  -webkit-transition-timing-function: ease-out;
}
.grid div:hover > .overlay {
  opacity: 1;
}
.grid div:hover {
  filter: brightness(1.2);
  -webkit-filter: brightness(1.2);
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.15), 0 4px 20px rgba(0, 0, 0, 0.3);
}
.grid div:hover > .show {
  opacity: 1;
  margin-bottom: 0;
}
.grid > div:nth-of-type(1) {
  grid-column: 1/3;
}
.grid > div:nth-of-type(2) {
  grid-column: 3/5;
  grid-row: 1/3;
}
.grid > div:nth-of-type(4) {
  grid-column: 2/3;
  grid-row: 2/4;
}

@media screen and (max-width: 840px) {
  .grid {
    height: auto;
    grid-template-columns: repeat(3, 1fr);
  }
  .grid div {
    min-height: auto;
    aspect-ratio: 1/2;
    width: 100%;
  }
  .grid > div:nth-of-type(1) {
    grid-column: 1/2;
  }
  .grid > div:nth-of-type(2) {
    grid-column: 1/4;
    grid-row: 1/2;
  }
  .grid > div:nth-of-type(4) {
    grid-column: 2/4;
    grid-row: 2/4;
  }
  
  /* 移动端背景图片适配 - iOS Safari 修复 */
  .bg-slide {
    background-size: cover;
    background-position: center center;
    /* iOS Safari 需要明确设置宽高 */
    width: 100vw;
    height: 100vh;
    /* 防止 iOS 地址栏变化导致的尺寸问题 */
    min-height: -webkit-fill-available;
  }
}