/* ========== Hero（深色顶栏，仅主标题） ========== */
.i40-hero {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  height: 560px;
  overflow: hidden;
  background: #111111;
}

.i40-hero__bg {
  position: absolute;
  inset: 0;
  background-position: center;
  background-size: cover;
  background-repeat: no-repeat;
}

.i40-hero__overlay {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.72);
}

.i40-hero__title {
  position: relative;
  z-index: 1;
  font-size: clamp(24px, 2.67vw, 52px);
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-white);
}

/* ========== 介绍卡片（标题 / 描述 / 按钮 / 配图） ========== */
.i40-intro {
  position: relative;
  z-index: 2;
  margin-top: 0;
  padding: 56px 0 64px;
  background: var(--color-bg-light);
}

.i40-intro__card {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 40px 56px;
  align-items: center;
  padding: 48px 48px 52px;
  background: var(--color-white);
  box-shadow:
    0 4px 14px rgba(0, 0, 0, 0.07),
    0 20px 50px rgba(0, 0, 0, 0.14);
}

.i40-intro__media img {
  display: block;
  width: 100%;
  max-width: 480px;
  margin: 0 auto;
  height: auto;
}

.i40-intro__heading {
  margin-bottom: 18px;
  font-size: clamp(22px, 2.2vw, 28px);
  font-weight: 700;
  line-height: 1.35;
  color: var(--color-text);
}

.i40-intro__text {
  margin-bottom: 28px;
  font-size: 16px;
  line-height: 1.75;
  color: var(--color-text-muted);
}

a.i40-intro__btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 32px;
  border: 2px solid var(--color-text);
  border-radius: 4px;
  font-size: 16px;
  font-weight: 600;
  color: var(--color-text);
  text-decoration: none;
  transition: background-color 0.2s ease, color 0.2s ease;
}

a.i40-intro__btn:hover {
  background: var(--color-text);
  color: var(--color-white);
}

/* ========== 内容区（左段落 + 右侧三图） ========== */
.i40-detail {
  padding: 0 0 80px;
  background: var(--color-bg-light);
}

.i40-detail__grid {
  display: grid;
  grid-template-columns: minmax(0, 0.95fr) minmax(0, 1.05fr);
  gap: 48px 56px;
  align-items: start;
}

.i40-detail__text p {
  margin-bottom: 20px;
  font-size: 16px;
  line-height: 1.75;
  color: var(--color-text);
}

.i40-detail__media {
  display: flex;
  flex-direction: column;
  gap: 12px;
  width: 100%;
  max-width: 300px;
  margin: 0 auto;
}

.i40-detail__media-top {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
}

.i40-detail__media-top img,
.i40-detail__media-bottom {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 2px;
}

@media (max-width: 960px) {
  .i40-intro__card,
  .i40-detail__grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .i40-intro__card {
    padding: 32px 24px 36px;
  }
}

@media (max-width: 640px) {
  .i40-hero {
    height: 420px;
  }
}