* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI",
               "PingFang SC", "Microsoft YaHei", sans-serif;
  background: linear-gradient(135deg, #6b9cff, #88e0d0);
  height: 100vh;
}

.login-wrapper {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100%;
}

.login-card {
  background: #fff;
  padding: 32px 28px;
  width: 90%;
  max-width: 360px;
  border-radius: 14px;
  box-shadow: 0 12px 30px rgba(0,0,0,0.15);
  text-align: center;
}

.title {
  margin: 0;
  font-size: 22px;
}

.subtitle {
  margin: 8px 0 20px;
  color: #666;
  font-size: 14px;
}

.form-group {
  margin-bottom: 14px;
}

input {
  width: 100%;
  padding: 12px 14px;
  font-size: 15px;
  border: 1px solid #ddd;
  border-radius: 8px;
  outline: none;
}

input:focus {
  border-color: #6b9cff;
}

.btn-primary {
  width: 100%;
  padding: 12px;
  background: #6b9cff;
  border: none;
  color: #fff;
  font-size: 16px;
  border-radius: 8px;
  cursor: pointer;
}

.btn-primary:active {
  opacity: 0.85;
}

.error-msg {
  margin-top: 12px;
  color: #e74c3c;
  font-size: 14px;
}

/* PC 优化 */
@media (min-width: 768px) {
  .login-card {
    padding: 40px 36px;
  }
}