.box {
  overflow: hidden;
  box-sizing: border-box;
  background: #f8f9fa; /* Changed to a light grey background for better contrast */
  padding: 0 0 2rem; /* Reduced bottom padding */
}

.banner {
  width: 100%;
  height: 10.8rem;
  background: url(../images/banner.png) no-repeat top center;
  background-size: 100% 100%;
  margin-bottom: 0.8rem;
  position: relative;
  box-sizing: border-box;
}

.min_title {
  font-size: 1.2rem;
  font-weight: bold;
  text-align: center;
  line-height: 1.5;
  color: #333; /* Darker color for better readability */
  margin: 1.5rem auto 1rem;
  position: relative;
}

.min_title::after {
  content: '';
  display: block;
  width: 2rem;
  height: 3px;
  background: #4436d3;
  margin: 0.3rem auto 0;
  border-radius: 2px;
}

.nav_big {
  display: flex;
  justify-content: center;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
}

.nav_big span {
  width: 5.5rem;
  line-height: 2.2rem;
  border-radius: 2rem;
  text-align: center;
  border: 1px solid #e0e0e0;
  background: #fff;
  color: #666;
  font-size: 0.9rem;
  cursor: pointer;
  transition: all 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275); /* Added bouncy transition */
  box-shadow: 0 2px 5px rgba(0,0,0,0.05);
}

.nav_big span:hover {
  transform: translateY(-2px);
  box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

.nav_big .on {
  background: #4436d3;
  color: #fff;
  border-color: #4436d3;
  box-shadow: 0 4px 12px rgba(68, 54, 211, 0.3);
  font-weight: bold;
  animation: pulseScale 2s infinite; /* Added pulse animation */
}

.list {
  background: #fff;
  margin: 0 0.8rem;
  border-radius: 1rem;
  padding: 1.2rem 0.8rem;
  box-shadow: 0 5px 20px rgba(0,0,0,0.05);
}

.nav {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 0.3rem;
  margin-bottom: 1rem;
}

.nav span {
  display: block;
  font-size: 0.75rem; /* Increased font size */
  width: 3.2rem;     /* Increased width */
  line-height: 1.6rem; /* Increased height */
  border: 1px solid #eee;
  background: #fdfdfd;
  color: #777;
  border-radius: 1rem;
  margin-bottom: 0.2rem; /* Added slight vertical spacing */
  cursor: pointer;
  text-align: center;
  box-sizing: border-box;
  transition: all 0.2s;
}

.nav span:active {
  transform: scale(0.9);
}

.nav .on {
  background: #fff4f1;
  color: #ff592e;
  border-color: #ff592e;
  font-weight: bold;
  animation: subtleBounce 1s infinite;
}

@keyframes pulseScale {
  0% { transform: scale(1); }
  50% { transform: scale(1.05); }
  100% { transform: scale(1); }
}

@keyframes subtleBounce {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-3px); }
}

.code_box {
  padding: 1rem 0;
  background: #fff;
  border-radius: 0.8rem;
}

.code {
  display: flex;
  flex-direction: column;
  align-items: center;
  animation: fadeIn 0.5s ease;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.code img {
  width: 65%;
  max-width: 250px;
  border: 8px solid #f9f9f9;
  border-radius: 0.5rem;
  box-shadow: 0 4px 15px rgba(0,0,0,0.08);
}

.code.small-code img {
  width: 50%;
  max-width: 180px;
}

/* 并排展示两个二维码的容器 */
.code.dual-code {
  flex-direction: row;
  justify-content: center;
  gap: 1rem;
  flex-wrap: wrap;
}

/* 单个二维码项容器 */
.code-item {
  display: flex;
  flex-direction: column;
  align-items: center;
}

/* 二维码图片容器 */
.code-item img {
  width: 45%;
  max-width: 180px;
  min-width: 200px;
  border: 8px solid #f9f9f9;
  border-radius: 0.5rem;
  box-shadow: 0 4px 15px rgba(0,0,0,0.08);
}

/* 地名标注样式 */
.code-item .city-name {
  margin-top: 0.5rem;
  font-size: 0.85rem;
  color: #333;
  font-weight: bold;
  text-align: center;
}

.code::after {
  content: '长按识别二维码进群';
  display: block;
  margin-top: 1rem;
  font-size: 0.8rem;
  color: #999;
}

.m-footer {
  margin-top: 2rem;
}

/* 弹窗样式 */
.popup-overlay {
  position: fixed;
  left: 0;
  top: 0;
  z-index: 9999;
  background: rgba(0, 0, 0, 0.6);
  width: 100%;
  height: 100%;
  display: none;
}

.popup-container {
  position: absolute;
  left: 0;
  top: 0;
  right: 0;
  bottom: 0;
  margin: auto;
  width: 438px;
  max-width: 90%;
  height: 430px;
  max-height: 80vh;
  background-size: contain;
  background-repeat: no-repeat;
  background-position: center top;
}

.popup-close {
  width: 30px;
  height: 30px;
  background-color: #fff;
  position: absolute;
  top: -10px;
  right: -10px;
  z-index: 2;
  padding: 5px;
  border-radius: 50%;
  transition: 0.2s;
  cursor: pointer;
  box-shadow: 0 2px 10px rgba(0,0,0,0.2);
}

.popup-close:hover {
  transform: rotate(180deg);
}

.popup-content {
  position: absolute;
  bottom: 50px;
  left: 0;
  right: 0;
  padding: 0 20px;
}

.popup-links {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 10px;
}

.popup-links a {
  width: 110px;
  height: 32px;
  background: linear-gradient(#83caff, #3d77fc);
  color: #fff;
  font-size: 14px;
  line-height: 32px;
  text-align: center;
  border-radius: 9px;
  text-decoration: none;
  font-weight: bold;
  transition: 0.2s;
}

.popup-links a:hover {
  opacity: 0.9;
  transform: translateY(-2px);
}

/* 移动端适配 */
@media screen and (max-width: 480px) {
  .popup-container {
    width: 320px;
    height: 320px;
  }
  
  .popup-links a {
    width: 90px;
    height: 28px;
    line-height: 28px;
    font-size: 12px;
  }
}