.page-about {
  --page-primary: #FF4D2E;
  --page-secondary: #0F2A43;
  --page-teal: #00C2A8;
  background: var(--color-bg-light);
}

/* 首屏 */
.page-about__hero {
  position: relative;
  overflow: hidden;
  padding: clamp(1.5rem, 4vw, 3rem) 0 clamp(3rem, 7vw, 5rem);
  border-bottom: 1px solid rgba(15, 42, 67, .1);
  background:
    radial-gradient(circle at 92% 8%, rgba(255, 77, 46, .12), transparent 34%),
    var(--color-bg-light);
}

.page-about__hero .breadcrumbs {
  margin-bottom: 2.75rem;
}

.page-about__hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2.5rem;
  align-items: center;
}

.page-about__title {
  margin-top: .5rem;
  font-size: clamp(2.2rem, 5.2vw, 3.8rem);
  line-height: 1.08;
  letter-spacing: -.03em;
  color: var(--page-secondary);
}

.page-about__lead {
  margin: .9rem 0 1rem;
  font-size: clamp(1.15rem, 2.4vw, 1.5rem);
  font-weight: 800;
  letter-spacing: -.01em;
  color: var(--page-primary);
}

.page-about__intro-text {
  max-width: 56ch;
  margin: 0;
  font-size: 1rem;
  line-height: 1.75;
  color: var(--color-muted);
}

.page-about__hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: .75rem;
  margin-top: 1.75rem;
}

.page-about__hero-media {
  position: relative;
}

.page-about__hero-imgwrap {
  position: relative;
  z-index: 1;
  overflow: hidden;
  border: 1px solid rgba(15, 42, 67, .12);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  transform: rotate(.6deg);
}

.page-about__hero-imgwrap img {
  display: block;
  width: 100%;
  height: auto;
}

.page-about__hero-media::after {
  content: "";
  position: absolute;
  top: 14px;
  left: 14px;
  right: 14px;
  bottom: 14px;
  border: 2px solid rgba(0, 194, 168, .45);
  border-radius: var(--radius-lg);
  pointer-events: none;
  z-index: 2;
}

.page-about__track-deco {
  position: absolute;
  top: 24px;
  right: 16px;
  width: clamp(130px, 18vw, 210px);
  height: auto;
  color: var(--page-primary);
  opacity: .6;
  display: none;
  pointer-events: none;
}

/* 品牌简介 */
.page-about__intro {
  padding: 5rem 0;
  background: transparent;
}

.page-about__mission {
  margin-top: 2.5rem;
  padding: 2rem 2.25rem;
  background: #fff;
  border: 1px solid rgba(15, 42, 67, .1);
  border-left: 6px solid var(--page-primary);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
}

.page-about__mission-title {
  margin: 0 0 .5rem;
  font-size: .85rem;
  font-weight: 800;
  letter-spacing: .12em;
  color: var(--page-teal);
}

.page-about__mission-text {
  margin: 0;
  font-size: 1.15rem;
  font-weight: 700;
  line-height: 1.65;
  color: var(--page-secondary);
}

/* 发展历程 */
.page-about__journey {
  padding: 5rem 0;
  background: #fff;
  border-top: 1px dashed rgba(15, 42, 67, .14);
}

.page-about__timeline {
  position: relative;
  display: grid;
  gap: 2.5rem;
  margin-top: 3rem;
}

.page-about__timeline-svg {
  display: none;
  position: absolute;
  left: 1px;
  top: 0;
  width: 12px;
  height: 100%;
  color: var(--page-teal);
  opacity: .35;
  pointer-events: none;
}

.page-about__timeline-item {
  position: relative;
  display: grid;
  grid-template-columns: 1fr;
  gap: .85rem;
}

.page-about__timeline-node {
  position: relative;
  z-index: 2;
  display: inline-flex;
  align-items: center;
  gap: .6rem;
  width: fit-content;
  border-radius: 999px;
  outline: none;
  cursor: help;
}

.page-about__timeline-dot {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--page-primary);
  box-shadow: 0 0 0 5px rgba(255, 77, 46, .16);
  transition: transform .2s ease;
}

.page-about__timeline-version {
  font-size: 1.1rem;
  font-weight: 900;
  letter-spacing: -.02em;
  color: var(--page-secondary);
  transition: color .2s ease;
}

.page-about__timeline-node:hover .page-about__timeline-dot,
.page-about__timeline-node:focus .page-about__timeline-dot {
  transform: scale(1.3);
}

.page-about__timeline-node:hover .page-about__timeline-version,
.page-about__timeline-node:focus .page-about__timeline-version {
  color: var(--page-primary);
}

.page-about__timeline-node::after {
  content: "";
  position: absolute;
  left: 0;
  top: calc(100% + 10px);
  display: none;
  width: max-content;
  max-width: 150px;
  padding: .5rem .75rem;
  background: var(--page-secondary);
  color: #fff;
  font-size: .8rem;
  font-weight: 500;
  line-height: 1.4;
  border-radius: var(--radius);
  box-shadow: var(--shadow-md);
  opacity: 0;
  transform: translateY(-4px);
  transition: opacity .2s ease, transform .2s ease;
  pointer-events: none;
  z-index: 5;
}

.page-about__timeline-node--v1::after { content: "第一版：赛程查询起点"; }
.page-about__timeline-node--v2::after { content: "第二版：比分数据接入"; }
.page-about__timeline-node--v3::after { content: "第三版：集锦与三栏雏形"; }
.page-about__timeline-node--v4::after { content: "第四版：V4版球迷记录与全新查询体验"; }

.page-about__timeline-node:hover::after,
.page-about__timeline-node:focus::after {
  opacity: 1;
  transform: translateY(0);
}

.page-about__timeline-content h3 {
  margin: 0 0 .475rem;
  font-size: 1.2rem;
  font-weight: 800;
  letter-spacing: -.01em;
  color: var(--page-secondary);
}

.page-about__timeline-content p {
  max-width: 62ch;
  margin: 0;
  font-size: .95rem;
  line-height: 1.7;
  color: var(--color-muted);
}

/* 数据规模 */
.page-about__data {
  padding: 5rem 0;
  color: rgba(255, 255, 255, .92);
  background: linear-gradient(145deg, var(--page-secondary) 0%, var(--color-bg-dark) 100%);
}

.page-about__data .section-title {
  color: #fff;
}

.page-about__data .kicker {
  color: var(--page-teal);
}

.page-about__stats {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
  margin-top: 2.75rem;
}

.page-about__stat {
  padding: 1.75rem 0 1.25rem;
  border-top: 3px solid rgba(255, 255, 255, .15);
}

.page-about__stat-num {
  display: block;
  width: fit-content;
  font-size: clamp(2rem, 4vw, 3.2rem);
  font-weight: 900;
  line-height: 1.1;
  letter-spacing: -.02em;
  color: #fff;
  font-variant-numeric: tabular-nums;
  text-decoration: underline;
  text-decoration-thickness: 4px;
  text-underline-offset: 8px;
  text-decoration-color: var(--page-teal);
}

.page-about__stat-label {
  display: block;
  margin-top: .9rem;
  font-size: .95rem;
  color: rgba(255, 255, 255, .72);
}

.page-about__data-media {
  max-width: 620px;
  margin: 3.5rem auto 0;
  text-align: center;
}

.page-about__data-media img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid rgba(255, 255, 255, .14);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
}

.page-about__data-caption {
  margin: 1rem 0 0;
  font-size: .875rem;
  color: rgba(255, 255, 255, .6);
}

/* 团队理念 */
.page-about__philosophy {
  padding: 5rem 0;
}

.page-about__philosophy-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2.5rem;
}

.page-about__philosophy-media img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
}

.page-about__values {
  display: grid;
  gap: 1rem;
  margin-top: 2rem;
}

.page-about__value {
  display: flex;
  gap: 1.25rem;
  align-items: flex-start;
  padding: 1.5rem;
  background: #fff;
  border: 1px solid rgba(15, 42, 67, .08);
  border-left: 4px solid var(--page-primary);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
}

.page-about__value-index {
  font-size: 1.6rem;
  font-weight: 900;
  line-height: 1;
  color: var(--page-primary);
  font-variant-numeric: tabular-nums;
}

.page-about__value-title {
  margin: 0 0 .4rem;
  font-size: 1.05rem;
  font-weight: 800;
  color: var(--page-secondary);
}

.page-about__value-body p {
  margin: 0;
  font-size: .95rem;
  line-height: 1.7;
  color: var(--color-muted);
}

.page-about__philosophy-note {
  max-width: 55ch;
  margin: 2rem 0 0;
  padding-top: 1.5rem;
  font-size: .95rem;
  line-height: 1.75;
  color: var(--color-muted);
  border-top: 1px dashed rgba(15, 42, 67, .18);
}

/* 断点 */
@media (min-width: 700px) {
  .page-about__stats {
    grid-template-columns: repeat(2, 1fr);
    column-gap: 2rem;
  }
}

@media (min-width: 900px) {
  .page-about__hero-grid {
    grid-template-columns: 1fr .9fr;
    gap: 4rem;
  }

  .page-about__track-deco {
    display: block;
  }

  .page-about__timeline-svg {
    display: block;
  }

  .page-about__timeline-item {
    grid-template-columns: 190px 1fr;
    gap: 2.5rem;
  }

  .page-about__timeline-node {
    margin-top: .45rem;
  }

  .page-about__timeline-node::after {
    display: block;
    left: calc(100% + 8px);
    top: 50%;
    transform: translateY(-50%) translateX(-4px);
  }

  .page-about__timeline-node:hover::after,
  .page-about__timeline-node:focus::after {
    transform: translateY(-50%) translateX(0);
  }

  .page-about__philosophy-grid {
    grid-template-columns: .8fr 1.2fr;
    gap: 4rem;
    align-items: center;
  }
}

@media (min-width: 1100px) {
  .page-about__stat-num {
    font-size: 3.2rem;
  }
}