p {
  font-size: 2rem;
}
:root{
  --primary-color: royalblue;
}
button{
  padding: 10px 32px;
  color: #000000d9;
  border: 1px solid #d9d9d9;
  background-color: transparent;
  border-radius: 2px;
  line-height: 1.4;
  box-shadow: 0 2px #00000004;
  cursor: pointer;
  transition: .3s;
  font-size: 2rem;
  margin: 10px;
  position: relative;
}
button:hover{
  color: var(--primary-color);
  border-color: currentColor;
}
button::after{
  position: absolute;
  inset: 0;
  border-radius: inherit;
  opacity: 0;
  box-shadow: 0 0 0 6px var(--primary-color);
  transition: .3s;
}
button:active::after{
  box-shadow: none;
  opacity: 0.4;
  transition: 0s;
}
body {
  background: #f0f0f0;
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100vh;
  margin: 0;
  flex-direction: column;
}
#pre{
  display: none;
}
#mask {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.5);
  z-index: 999;
  display:none;
}
#cu{
  font-size:5rem;
  text-align: center;
}
#m{
  max-width: 90%;
  max-height: 90%;
  background: #ffffff;
  box-shadow: rgba(0, 0, 0, 0.25) 0px 0.0625em 0.0625em, rgba(0, 0, 0, 0.25) 0px 0.125em 0.5em, rgba(255, 255, 255, 0.1) 0px 0px 0px 1px inset;
  border-radius:30px;
  margin: 40px;
  padding: 20px;
  overflow: auto;
}
.hide{
  display: none;
}
.ques{
  align-items: center;
  justify-content: center;
  display: none;
  flex-wrap:wrap;
}
.container {
  margin: 20px;
  display: flex;
  flex-wrap:wrap;
  column-width: 200px;
}
img{
  min-width:20%;
  max-width: 100%;
  margin: 40px;
}
#qu{
  max-width: 400px;
  margin: 40px;
}
.card {
  width: 200px;
  height: 300px;
  border: 1px solid rgb(0, 0, 0);
  border-radius: 8px;
  background-color: #fdfdf8;
  position: relative;
  transition: transform 0.5s ease;
  transform-style: preserve-3d; /* Enables 3D transforms */
  margin: 10px;
}

.card-inner {
  width: 100%;
  height: 100%;
  position: absolute;
  backface-visibility: hidden; /* Hides the back side during rotation */
}

.card-front{
  width: 100%;
  height: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
  position: absolute;
  -webkit-backface-visibility: hidden; /* Safari fix */
  backface-visibility: hidden;
}
.im{
  max-width: 100%;
  max-height: 100%;
}
.deck {
  display: flex;
  justify-content: center;
  align-items: center;
  position: relative;
  display: flex;
  flex-wrap:wrap;
  margin:30px
}
#ala{
  text-align: center;
}
#point{
  font-size: 2rem;   /*设置文字大小*/
  color:#3366FF;  /*设置文字颜色*/
  text-shadow: 0 8px 10px #6699FF;  /*设置文字阴影*/                  
  font-weight: bolder;  /*设置文字宽度*/                              
  text-align: center;  /*设置文字居中*/                              
}
#cen{
  display: flex;
  align-items: center;
  justify-content: center;
  flex-flow: column;
}

#game-intro {
  text-align: center;
  margin: 20px;
  padding: 20px;
}

#game-intro h1 {
  color: #3366FF;
  font-size: 3rem;
  margin-bottom: 20px;
  text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
}

.game-rules {
  background-color: rgba(255, 255, 255, 0.9);
  padding: 20px;
  border-radius: 15px;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
  margin: 0 auto;
  max-width: 600px;
}

.game-rules ol {
  text-align: left;
  margin: 10px 0;
  padding-left: 30px;
}

.game-rules li {
  font-size: 1.2rem;
  margin: 10px 0;
  line-height: 1.5;
}

.register {
    text-align: center;
    padding: 40px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 20px;
    max-width: 300px;
    margin: 0 auto;
}

.form-group input {
    padding: 10px;
    font-size: 1.2rem;
    border: 1px solid #ccc;
    border-radius: 4px;
}

.start-btn {
    background-color: #3366FF;
    color: white;
    border: none;
    padding: 12px;
    font-size: 1.2rem;
    cursor: pointer;
    transition: background-color 0.3s;
}

.start-btn:hover {
    background-color: #2952cc;
    color: white;
}