body {
  background: #fff;
  font-family: 'Microsoft YaHei', Arial, sans-serif;
  margin: 0;
  padding: 0;
}
.header {
  text-align: center;
  margin-top: 40px;
  font-size: 60px;
  font-weight: bold;
  color: #f00;
}
.big-x { font-size: 80px; }
.big-3 { font-size: 80px; margin-left: 40px; }
.box {
  background: #fff;
  border: 1px solid #eee;
  margin: 40px auto;
  padding: 30px 20px;
  max-width: 90vw;
  min-width: 300px;
  border-radius: 8px;
  box-shadow: 0 2px 8px #eee;
}
h3 {
  color: #2196f3;
  font-size: 28px;
  margin-bottom: 20px;
}
.line-group {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
}
.line-btn {
  background: #f7fbfe;
  border: 2px solid #b6e0fe;
  border-radius: 12px;
  padding: 12px 32px;
  font-size: 22px;
  color: #222;
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  min-width: 120px;
  justify-content: center;
}
.delay {
  color: #f88;
  font-size: 16px;
  margin-left: 8px;
}
.login-container {
  max-width: 350px;
  margin: 120px auto;
  padding: 40px 30px;
  background: #fff;
  border-radius: 10px;
  box-shadow: 0 2px 12px #eee;
  text-align: center;
}
input[type="password"] {
  width: 80%;
  padding: 10px;
  font-size: 18px;
  margin-bottom: 20px;
  border-radius: 6px;
  border: 1px solid #ccc;
}
button {
  padding: 10px 30px;
  font-size: 18px;
  background: #2196f3;
  color: #fff;
  border: none;
  border-radius: 6px;
  cursor: pointer;
}
@media (max-width: 600px) {
  .header { font-size: 36px; }
  .big-x, .big-3 { font-size: 48px; }
  .box { padding: 16px 6px; }
  .line-btn { font-size: 16px; padding: 8px 12px; min-width: 80px; }
  h3 { font-size: 20px; }
}