:root {
    --primary: #0071e3;
    --background: #fbfbfd;
    --text: #1d1d1f;
    --muted: #86868b;
    --button-bg: #e8e8ed;
    --button-text: #000000;
    --button-hover: #d2d2d7;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--background);
    color: var(--text);
    line-height: 1.47059;
    font-weight: 400;
    letter-spacing: -.022em;
    margin: 0;
    padding: 0;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

header {
    background-color: rgba(251, 251, 253, 0.8);
    backdrop-filter: saturate(180%) blur(20px);
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 9999;
}

nav {
    max-width: 980px;
    margin: 0 auto;
    padding: 20px 22px;
    height: 44px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo-container {
    display: flex;
    align-items: center;
}

.logo-img {
    width: 48px;
    height: 48px;
    margin-right: 10px;
}

.app-name {
    font-size: 21px;
    font-weight: 600;
}

.nav-links {
    list-style: none;
    display: flex;
    gap: 20px;
    margin: 0;
    padding: 0;
}

.nav-button {
    background-color: var(--button-bg);
    color: var(--button-text);
    border: none;
    padding: 8px 16px;
    border-radius: 980px;
    font-size: 14px;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

.nav-button:hover {
    background-color: var(--button-hover);
}

/* 电脑端：文A图标显示在右上角 */
.lang-button {
    background: none; /* 去除背景 */
    border: none; /* 去除边框 */
    position: absolute; /* 使用绝对定位 */
    top: 10px; /* 距离顶部的距离 */
    right: 20px; /* 距离右侧的距离 */
    padding: 0; /* 移除按钮的默认内边距 */
    cursor: pointer; /* 光标指针样式 */
}

.lang-icon {
    font-size: 18px; /* 设置适合电脑显示的字体大小 */
    font-weight: bold;
}

main {
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 80px 22px 22px;
    text-align: center;
}

h1 {
    font-size: 40px;
    line-height: 1.07143;
    font-weight: 600;
    letter-spacing: -.005em;
    margin-bottom: 6px;
}

#downloadPrompt {
    font-size: 22px;
    line-height: 1.10722;
    font-weight: 400;
    letter-spacing: .004em;
    margin-bottom: 40px;
    color: var(--muted);
}
#detectedOS {
    font-size: 18px;
    line-height: 2;
    letter-spacing: .004em;
    margin-bottom: 20px;
    color: var(--muted);
}

.download-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
    margin: 2rem 0;
    max-width: 800px;
    width: 100%;
}

@media (min-width: 768px) {
    .download-grid {
        grid-template-columns: repeat(4, 1fr);
    }
}

.download-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-decoration: none;
    color: var(--text);
    transition: all 0.3s ease;
}


.download-item:hover {
    transform: scale(1.05);
    box-shadow: 0 6px 8px rgba(0, 0, 0, 0.15);
}

.icon-container {
    width: 64px;
    height: 64px;
    margin-bottom: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.icon-container svg {
    width: 40px;
    height: 40px;
}

.windows {
    background-color: #0078d7;
}

.macos, .ios {
    background-color: #000000;
}

.android {
    background-color: #3DDC84;
}

.windows svg, .macos svg, .ios svg {
    fill: #ffffff;
}

.android svg {
    fill: #000000;
}

.download-item span {
    font-size: 17px;
    line-height: 1.23536;
    font-weight: 400;
    letter-spacing: -.022em;
}

/* 让 footer 内部的内容为相对定位，便于定位按钮 */
/* 确保页脚相对定位 */
footer {
    position: relative;
    background-color: #f5f5f7;
    padding: 16px 22px;
    text-align: center;
    color: var(--muted);
    font-size: 12px;
    line-height: 1.33337;
    font-weight: 400;
    letter-spacing: -.01em;
}

/* 文A 按钮的样式，固定在页面底部左侧 */
#languageToggle {
    position: absolute; /* 使用绝对定位 */
    bottom: 20px;  /* 距离页面底部20px */
    left: 20px;    /* 距离页面左侧20px */
    background: none; /* 去除背景 */
    border: none;  /* 去除边框 */
    cursor: pointer;
    font-size: 16px; /* 设置字体大小 */
}
.lang-button1 {
    background: none; /* 去除背景 */
    border: none; /* 去除边框 */
    position: absolute; /* 使用绝对定位 */
    top: 10px; /* 距离顶部的距离 */
    left: 20px; /* 距离右侧的距离 */
    padding: 0; /* 移除按钮的默认内边距 */
    cursor: pointer; /* 光标指针样式 */
}

.lang-icon1 {
    font-size: 18px;
}
/* 确保版权信息居中显示 */
footer p {
    margin: 0;
    text-align: center;
}


#loginRegisterBtn {
    display: none;
}
@media (max-width: 768px) {
    h1 {
        font-size: 22px;
    }

    #downloadPrompt {
        font-size: 16px;
    }

    .nav-links {
        gap: 2px;
    }

    .nav-button {
        padding: 6px 12px;
        font-size: 12px;
        position: relative;
    }

    .app-name {
        font-size: 18px;
    }
    .lang-button {
        position: absolute; /* 使用绝对定位以便自由调整位置 */
        top: 50%; /* 垂直居中 */
        transform: translateY(-50%); /* 垂直居中的同时确保完全居中对齐 */
        right: 10px; /* 贴近右侧 */
        padding: 0; /* 移除按钮默认内边距 */
    }
    .lang-icon {
        font-size: 12px;
        font-weight: normal;/* 手机端稍微缩小字体 */
    }
    #Linkhealth {
        display: none;  隐藏文字按钮
    }
    #detectedOS {
    font-size: 14px;
    line-height: 2;
    letter-spacing: .004em;
    margin-bottom: 20px;
    color: var(--muted);
}
}
#loadingOverlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.7); /* 半透明背景 */
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000; /* 保证覆盖在最上层 */
}

.loading-message {
    color: black;
    background-color: white; /* 设置背景为白色 */
    padding: 20px; /* 内边距 */
    border-radius: 10px; /* 圆角 */
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.5); /* 阴影效果 */
    font-size: 18px;
    font-weight: bold;
}
.tooltip {
    display: none; /* 默认隐藏 */
    position: absolute; /* 绝对定位 */
    bottom: 100%; /* 在元素的上方显示 */
    margin-bottom: 20px;
    left: 50%;
    transform: translateX(-50%); /* 水平居中 */
    background-color: rgba(0, 0, 0, 0.7); /* 黑色背景，半透明 */
    color: #fff; /* 白色文字 */
    padding: 8px;
    border-radius: 4px;
    font-size: 12px;
    white-space: nowrap; /* 保证文字不换行 */
    z-index: 999; /* 确保提示框位于最上层 */
}

/* 鼠标悬停时显示提示框 */
.download-item:hover .tooltip {
    display: block; /* 鼠标悬停时显示 */
}
.popup-float {
    position: fixed;
    bottom: 60px;
    left: 10px;
    max-width: 400px;
    background-color: white;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    padding: 20px;
    z-index: 1000;
    line-height: 2;
  }
  .popup-float div {
    font-size: 14px;
  }

  .popup-float h2 {
    margin-top: 0;
    font-size: 20px;
    font-weight: bold;
  }
  .popup-float h4 {
    margin: 0 0 10px 0;
    font-size: 16px;
    font-weight: bold;
  }
  .popup-float a {
    color: #000;
    text-decoration: none;
  }
  .popup-float p {
    margin-top: 0;
    font-size: 14px;
  }

  .popup-float .countdown {
    position: absolute;
    top: 10px;
    right: 15px;
    font-size: 14px;
    color: #7c7c7c;
    font-weight: bold;
  }

  .popup-float button {
    color: white;
    background-color: #007bff;
    border: none;
    display: flex;
    justify-content: center;
    align-items: center;
    margin: 0px auto;
    padding: 10px 30px;
    border-radius: 8px;
    cursor: pointer;
    text-align: center;
    line-height: 1.3;
  }

  @media (max-width: 768px) {
    .popup-float {
      bottom: 60px;
      left: 10px;
      right: 10px;
      max-width: none;
      font-size: 14px;
    }
  }