a { text-decoration: none; }

/* 返回首页：卡片下方文字链接 */
.back-home {
  max-width: 420px;
  margin: 16px auto 0;
  text-align: center;
}
.back-home a {
  font-size: 16px;
  color: #409eff;
}
.back-home a:active {
  opacity: 0.7;
}
@media (hover: hover) {
  .back-home a:hover {
    text-decoration: underline;
  }
}

body {
  margin: 0;
  padding: 16px 14px calc(24px + env(safe-area-inset-bottom));
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  color: #1f2937;
  background:
    radial-gradient(circle at 20% 0%, #cfe6ff 0%, transparent 55%),
    radial-gradient(circle at 100% 100%, #d4e8ff 0%, transparent 50%),
    linear-gradient(160deg, #eaf3ff 0%, #f5f9ff 60%, #ffffff 100%);
  background-attachment: fixed;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -webkit-tap-highlight-color: transparent;
}

/* 顶部 LOGO：蓝底白字 云 */
.logo {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 56px;
  height: 56px;
  margin: 0 0 8px;
  vertical-align: middle;
  border-radius: 16px;
  background: linear-gradient(135deg, #1e90ff 0%, #007bff 100%);
  box-shadow: 0 6px 16px rgba(0, 92, 191, 0.35);
  color: #fff;
  font-size: 28px;
  font-weight: 700;
  letter-spacing: 1px;
  line-height: 1;
}

/* 卡片：表单作为卡片 */
#form {
  max-width: 420px;
  margin: 18px auto 0;
  background: #ffffff;
  border-radius: 18px;
  box-shadow:
    0 1px 0 rgba(255, 255, 255, 0.8) inset,
    0 10px 30px rgba(0, 92, 191, 0.12),
    0 2px 6px rgba(0, 0, 0, 0.04);
  padding: 24px 22px 28px;
  box-sizing: border-box;
}

/* 编码输入框 */
input[name="bianma"] {
  -webkit-appearance: none;
  appearance: none;
  display: block;
  width: 100%;
  max-width: 340px;
  height: 48px;
  margin: 0 auto;
  padding: 0 14px;
  font-size: 16px;
  color: #333333;
  background: #ffffff;
  border: 1px solid #dcdfe6;
  border-radius: 6px;
  outline: none;
  box-sizing: border-box;
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}
input[name="bianma"]::placeholder {
  color: #c0c4cc;
  font-size: 15px;
}
input[name="bianma"]:focus {
  background-color: #ffffff;
  border-color: #409eff;
  box-shadow: 0 0 4px rgba(64, 158, 255, 0.5);
}
input[name="bianma"]:-webkit-autofill,
input[name="bianma"]:-webkit-autofill:hover,
input[name="bianma"]:-webkit-autofill:focus,
input[name="bianma"]:-webkit-autofill:active {
  -webkit-box-shadow: 0 0 0 1000px #ffffff inset;
  box-shadow: 0 0 0 1000px #ffffff inset;
  -webkit-text-fill-color: #333333;
  caret-color: #333333;
  transition: background-color 99999s ease-out 0s;
}

/* 登录按钮 */
input[type="submit"] {
  -webkit-appearance: none;
  appearance: none;
  cursor: pointer;
  display: block;
  box-sizing: border-box;
  width: 100%;
  max-width: 340px;
  margin: 24px auto 0;
  min-height: 48px;
  padding: 12px 22px;
  font-size: 16px;
  font-weight: 500;
  color: #ffffff;
  letter-spacing: 0;
  text-align: center;
  border: none;
  border-radius: 8px;
  background-color: #6384ff;
  box-shadow: none;
  transition: background-color 0.15s ease, opacity 0.15s ease;
}
input[type="submit"]:active {
  background-color: #5576f0;
  opacity: 0.92;
}
@media (hover: hover) {
  input[type="submit"]:hover {
    background-color: #728fff;
  }
}