@import url('https://fonts.googleapis.com/css?family=Roboto+Mono:400,700');

/* 容器范围限定，避免污染全局 */
.card_wrapper, .card_wrapper * {
  box-sizing: border-box;
  font-weight: normal;
  font-family: 'Roboto Mono', 'Courier New', monospace;
  color: #555;
}

/* 容器背景和文字居中 */
.card_wrapper {
  background: #222;
  padding: 1em;
  text-align: center;
}

/* 标题 - 响应式字体 */
.card_wrapper card_h1 {
  font-size: clamp(1.5em, 4vw, 2.2em);
  margin: 0 0 0.5em;
}

/* Base flip styles - 响应式设计 */
.card_flip {
  position: relative;
  display: inline-block;
  margin-right: 2px;
  margin-bottom: 1em;
  width: clamp(280px, 90vw, 374px); /* 响应式宽度 */
  max-width: 374px;
  cursor: pointer;
  perspective: 1000px;
}

.card_flip > .card_front,
.card_flip > .card_back {
  display: block;
  color: white;
  width: 100%;
  background-size: cover !important;
  background-position: center !important;
  height: clamp(160px, 40vw, 220px); /* 响应式高度 */
  padding: clamp(0.8em, 3vw, 1em) clamp(1.2em, 4vw, 2em); /* 响应式内边距 */
  background: #313131;
  border-radius: clamp(8px, 2vw, 10px); /* 响应式圆角 */
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  box-sizing: border-box;
}

.card_flip > .card_front p,
.card_flip > .card_back p {
  font-size: clamp(0.7rem, 2vw, 0.8rem); /* 响应式字体 */
  line-height: 160%;
  color: #999;
  margin: 0;
}

/* 卡片标题响应式字体 */
.card_flip > .card_front card_h1,
.card_flip > .card_back h2 {
  font-size: clamp(1.2em, 3.5vw, 1.8em);
  margin-bottom: clamp(0.3em, 2vw, 0.5em);
}

/* 优化 card_h1 元素样式 */
card_h1 {
  display: block;
  font-weight: bold;
  font-family: 'Roboto Mono', 'Courier New', monospace;
  color: inherit;
  margin: 0;
}

/* 确保 card_h1 能够正确应用 text-shadow */
card_h1.card_text-shadow {
  text-shadow:
    1px 1px rgba(0, 0, 0, 0.1),
    2px 2px rgba(0, 0, 0, 0.08),
    3px 3px rgba(0, 0, 0, 0.06),
    4px 4px rgba(0, 0, 0, 0.04);
}

.card_flip > .card_front {
  transform: rotateY(0deg);
  transition: transform 0.5s cubic-bezier(.175, .885, .32, 1.275), opacity 0.5s;
  position: relative;
  z-index: 2;
}

.card_flip > .card_back {
  position: absolute;
  opacity: 0;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  transform: rotateY(-180deg);
  transition: transform 0.5s cubic-bezier(.175, .885, .32, 1.275), opacity 0.5s;
  z-index: 1;
}

.card_flip:hover > .card_front {
  transform: rotateY(180deg);
  opacity: 0;
  z-index: 1;
}

.card_flip:hover > .card_back {
  opacity: 1;
  transform: rotateY(0deg);
  z-index: 2;
}

/* Flip vertical */
.card_flip.card_flip-vertical > .card_back {
  transform: rotateX(-180deg);
}

.card_flip.card_flip-vertical:hover > .card_front {
  transform: rotateX(180deg);
  opacity: 0;
  z-index: 1;
}

.card_flip.card_flip-vertical:hover > .card_back {
  transform: rotateX(0deg);
  opacity: 1;
  z-index: 2;
}

/* 阴影文字效果 - 优化移动端性能 */
.card_text-shadow {
  text-shadow:
    1px 1px rgba(0, 0, 0, 0.1),
    2px 2px rgba(0, 0, 0, 0.08),
    3px 3px rgba(0, 0, 0, 0.06),
    4px 4px rgba(0, 0, 0, 0.04);
}

/* 移动端优化 */
@media (max-width: 768px) {
  .card_flip {
    width: calc(100% - 4px);
    margin-right: 0;
    margin-bottom: clamp(0.8em, 3vw, 1.2em);
  }
  
  .card_flip > .card_front,
  .card_flip > .card_back {
    height: clamp(140px, 35vw, 180px);
    padding: clamp(0.6em, 3vw, 0.8em) clamp(1em, 4vw, 1.5em);
  }
  
  /* 移动端触摸优化 */
  .card_flip:active > .card_front {
    transform: rotateY(180deg);
    opacity: 0;
    z-index: 1;
  }

  .card_flip:active > .card_back {
    opacity: 1;
    transform: rotateY(0deg);
    z-index: 2;
  }
  
  .card_flip.card_flip-vertical:active > .card_front {
    transform: rotateX(180deg);
    opacity: 0;
    z-index: 1;
  }

  .card_flip.card_flip-vertical:active > .card_back {
    transform: rotateX(0deg);
    opacity: 1;
    z-index: 2;
  }
}

/* 小屏幕设备进一步优化 */
@media (max-width: 480px) {
  .card_flip > .card_front,
  .card_flip > .card_back {
    height: clamp(120px, 30vw, 160px);
    padding: clamp(0.5em, 2.5vw, 0.7em) clamp(0.8em, 3vw, 1.2em);
  }
  
  .card_flip > .card_front card_h1,
  .card_flip > .card_back h2 {
    font-size: clamp(1em, 4vw, 1.4em);
  }
  
  .card_flip > .card_front p,
  .card_flip > .card_back p {
    font-size: clamp(0.6rem, 2.5vw, 0.75rem);
  }
}