.challenge-section {
  width: 100%;
  padding: 40px 20px  50px;
  box-sizing: border-box;
  background: #fff;
}

.challenge-inner {
  max-width: 1420px;
  margin: 0 auto;
}

.challenge-title {
  font-size: 34px;
  font-weight: normal;
  color: #000;
  text-align: center;
  padding-bottom: 18px;
  margin-bottom: 34px;
}

.challenge-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px 34px;
}

.challenge-card {
  padding: 32px 34px;
  box-sizing: border-box;
  background: #fff;
  border-left: 4px solid #0fb100;
  border-radius: 8px;
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.08);
}

.card-title {
  font-size: 20px;
  line-height: 1.5;
  font-weight: 500;
  color: #000;
}

/* 平板 */
@media (max-width: 1024px) {
  .challenge-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .challenge-title {
    font-size: 30px;
  }
}

/* 手机 */
@media (max-width: 640px) {
  .challenge-section {
    padding: 36px 16px;
  }

  .challenge-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .challenge-title {
    font-size: 26px;
    margin-bottom: 26px;
  }

  .challenge-card {
    min-height: 120px;
    padding: 26px 24px;
  }

  .card-title {
    font-size: 18px;
  }
}