.construction-section {
  position: relative;
}

.construction-section > .container {
  position: relative;
  margin: 0 auto;
  max-width: min(1200px, 100%);
  padding-inline: clamp(16px, 4vw, 40px);
  z-index: 1;
  text-align: center;
}

.construction-section > .container > .title-box {
  box-sizing: border-box;
  max-width: 100%;
  background-color: #fff;
  border-radius: clamp(2px, 0.5vw, 6px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08), 0 2px 6px rgba(0, 0, 0, 0.05);
}

h2.construction-title {
  color: #fff;
  font-size: clamp(22px, 3.5vw, 60px);
  font-weight: 800;
  padding: 10px 0;
}

.construction-section > .container > .card-box {
  box-sizing: border-box;
  max-width: 100%;
  margin-top: clamp(20px, 10vw, 60px);
  background-color: #f0f9ff;
  border-radius: clamp(12px, 1vw, 42px);
  padding: 0;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08), 0 2px 6px rgba(0, 0, 0, 0.05);
  overflow: hidden;
}

.step-wapper {
  margin: clamp(10px, 2.2vw, 30px) auto;
  padding: 20px;
  display: grid;
  grid-template-columns: repeat(6, 120px);
  gap: 60px;
  justify-content: center;
}

.step-card {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  background-color: #333;
  width: 100%;
  height: 300px;
  box-shadow: inset 0 0 0 1px rgba(0, 0, 0, 0.05);
}
.step-card:not(:last-child)::after {
  content: "";
  position: absolute;
  right: -36px;
  top: 50%;
  transform: translateY(-50%);
  width: 0;
  height: 0;
  border-top: 10px solid transparent;
  border-bottom: 10px solid transparent;
  border-left: 14px solid #3f99d7;
  opacity: 0.8;
}

.step-card:nth-child(1) {
  background-color: #8bd0ff;
}
.step-card:nth-child(2) {
  background-color: #69c2ff;
}
.step-card:nth-child(3) {
  background-color: #4ab5ff;
}
.step-card:nth-child(4) {
  background-color: #51b0f0;
}
.step-card:nth-child(5) {
  background-color: #47a6e6;
}
.step-card:nth-child(6) {
  background-color: #469cd7;
}

.step-number {
  margin: 5px;
  padding: 6px 14px;
  background-color: #fff;
  color: #3f99d7;
  font-size: 12px;
  font-weight: 700;
  border-radius: 999px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.step-title {
  writing-mode: vertical-rl;
  text-orientation: upright;
  margin: 12px auto;
  font-size: 28px;
  font-weight: 700;
  color: #fff;
  letter-spacing: 0.1em;
}

.flow-message-box {
  position: relative;
  margin: clamp(12px, 3vw, 20px) auto 30px;
  padding: clamp(12px, 3vw, 20px);
  max-width: 900px;
  width: 80%;
  background-color: rgba(255, 255, 255, 0.85);
  border-radius: 12px;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.08);
  text-align: center;
}

.flow-message {
  margin: 0;
  font-size: clamp(11px, 2.5vw, 24px);
  line-height: 1.8;
  color: #333;
  font-weight: 800;
}

.flow-message-img {
  position: absolute;
  width: clamp(54px, 15vw, 200px);
  aspect-ratio: 1\1;
  top: 50%;
  transform: translateY(-50%);
  right: 0;
}

@media (max-width: 1200px) {
  .step-wapper {
    grid-template-columns: 1fr;
    gap: 35px;
  }

  .step-card {
    flex-direction: row;
    align-items: center;
    height: auto;
    padding: 16px;
    width: 80%;
    margin: 0 auto;
  }

  .step-number {
    font-size: 12px;
    margin: 0 12px 0 0;
  }

  .step-title {
    writing-mode: horizontal-tb;
    text-orientation: mixed;
    margin: 0;
    font-size: clamp(16px, 4vw, 20px);
    letter-spacing: 0.05em;
  }

  .step-card:not(:last-child)::after {
    right: auto;
    top: auto;
    left: 50%;
    bottom: -25px;
    transform: translateX(-50%);

    /* 三角を下向きに作り直す */
    border-left: 10px solid transparent;
    border-right: 10px solid transparent;
    border-top: 14px solid #3f99d7;
    border-bottom: 0;

    opacity: 0.8;
  }
}