.page-about {
  --ab-radius: 22px;
  --ab-radius-alt: 12px;
}

/* ---------- 面包屑 ---------- */
.page-about .crumbs {
  margin: 26px 0 0;
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.page-about .crumbs a {
  color: var(--muted);
  text-decoration: none;
  transition: color 0.24s var(--ease);
}

.page-about .crumbs a:hover,
.page-about .crumbs a:focus-visible {
  color: var(--cyan);
}

.page-about .crumbs [aria-current="page"] {
  color: var(--cyan);
}

/* ---------- 首屏 ---------- */
.page-about .hero {
  position: relative;
  padding: 30px 0 8px;
  overflow: hidden;
}

.page-about .hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 34px;
  align-items: center;
}

.page-about .hero__title {
  margin: 14px 0 0;
  font-size: clamp(44px, 10.5vw, 88px);
  font-weight: 200;
  line-height: 1.04;
  letter-spacing: 0.005em;
  color: var(--ink);
}

.page-about .hero__lede {
  margin-top: 20px;
  max-width: 34em;
}

.page-about .hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

.page-about .hero__visual {
  position: relative;
  width: 100%;
  max-width: 480px;
  margin: 0 auto;
  aspect-ratio: 1 / 1;
  border: 1px solid var(--line);
  border-radius: var(--ab-radius) var(--ab-radius-alt) var(--ab-radius) var(--ab-radius-alt);
  background: var(--panel);
  overflow: hidden;
  box-shadow: var(--shadow);
}

.page-about .hero-vis__grid {
  position: absolute;
  inset: 0;
  opacity: 0.55;
}

.page-about .hero-vis__glow {
  position: absolute;
  inset: -20% -10% 40% -20%;
  background: var(--grad-focus);
  opacity: 0.3;
  filter: blur(46px);
  border-radius: 50%;
}

.page-about .hero-vis__svg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

.page-about .hv-axis {
  stroke: var(--line);
  stroke-width: 1;
  stroke-dasharray: 3 6;
}

.page-about .hv-line {
  fill: none;
  stroke-width: 3;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.page-about .hv-dots circle {
  fill: var(--cyan);
}

.page-about .hv-ticks line {
  stroke: var(--muted);
  stroke-width: 1;
  opacity: 0.6;
}

.page-about .hero-vis__tag {
  position: absolute;
  left: 20px;
  bottom: 18px;
  font-size: 11px;
  letter-spacing: 0.22em;
  color: var(--muted);
}

/* ---------- 首屏数据条 ---------- */
.page-about .hero-stats {
  list-style: none;
  margin: 40px 0 0;
  padding: 22px 0 0;
  border-top: 1px solid var(--line);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 22px 18px;
}

.page-about .stat {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.page-about .stat__num {
  font-size: 28px;
  font-weight: 500;
  letter-spacing: 0.04em;
}

.page-about .stat__label {
  font-size: 13px;
  color: var(--muted);
  letter-spacing: 0.06em;
}

/* ---------- 章节骨架 ---------- */
.page-about .chap-sec {
  position: relative;
}

.page-about .chap {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 20px;
}

.page-about .chap__aside {
  display: flex;
  align-items: baseline;
  gap: 14px;
}

.page-about .chap__num {
  display: block;
  font-size: clamp(56px, 15vw, 118px);
  line-height: 0.86;
  font-weight: 200;
  letter-spacing: -0.02em;
  color: var(--rail);
}

@supports (-webkit-background-clip: text) {
  .page-about .chap__num {
    background: var(--grad-flow);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    color: transparent;
  }
}

.page-about .chap__title {
  margin: 0;
  font-size: clamp(28px, 6vw, 44px);
  font-weight: 300;
  line-height: 1.22;
  letter-spacing: 0.01em;
  color: var(--ink);
}

.page-about .chap__lede {
  margin: 16px 0 0;
  max-width: 40em;
  color: var(--muted);
  line-height: 1.8;
}

.page-about .chap__foot {
  margin: 30px 0 0;
  padding: 18px 20px;
  border-left: 3px solid var(--cyan);
  border-radius: 0 var(--ab-radius) var(--ab-radius) 0;
  background: var(--panel);
  color: var(--muted);
  line-height: 1.8;
}

.page-about .chap__foot a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid var(--line);
}

.page-about .chap__foot a:hover,
.page-about .chap__foot a:focus-visible {
  border-bottom-color: var(--cyan);
}

/* ---------- 图片容器 ---------- */
.page-about .shot {
  margin: 26px 0 0;
  border: 1px solid var(--line);
  border-radius: var(--ab-radius) var(--ab-radius-alt) var(--ab-radius) var(--ab-radius-alt);
  background: var(--panel);
  overflow: hidden;
}

.page-about .shot img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
}

.page-about .shot--wide img {
  aspect-ratio: 16 / 9;
  height: auto;
  object-fit: cover;
}

.page-about .shot--4x3 img {
  aspect-ratio: 3 / 2;
  height: auto;
  object-fit: cover;
}

.page-about .shot--side {
  margin-top: 26px;
}

.page-about .shot--side img {
  aspect-ratio: 4 / 3;
  height: auto;
  object-fit: cover;
}

.page-about .media__cap {
  padding: 12px 18px 16px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
}

/* ---------- 01 标签页 ---------- */
.page-about .tabs {
  margin-top: 30px;
}

.page-about .tablist {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--line);
}

.page-about .tab {
  appearance: none;
  border: 1px solid var(--line);
  background: transparent;
  color: var(--muted);
  font: inherit;
  font-size: 14px;
  letter-spacing: 0.08em;
  padding: 10px 18px;
  border-radius: 999px;
  cursor: pointer;
  transition: color 0.26s var(--ease), border-color 0.26s var(--ease), background 0.26s var(--ease);
}

.page-about .tab:hover,
.page-about .tab:focus-visible {
  color: var(--ink);
  border-color: var(--cyan);
}

.page-about .tab[aria-selected="true"] {
  color: var(--bg);
  background: var(--cyan);
  border-color: var(--cyan);
}

.page-about .tabpanel {
  display: block;
  padding: 22px 0 0;
}

.page-about .js .tabpanel {
  display: none;
}

.page-about .js .tabpanel.is-active {
  display: block;
}

.page-about .pane__lead {
  margin: 0;
  max-width: 38em;
  line-height: 1.85;
  color: var(--ink);
}

.page-about .pane__list {
  list-style: none;
  margin: 20px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .pane__list li {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
  padding: 12px 16px;
  border: 1px solid var(--line);
  border-radius: var(--ab-radius-alt);
  background: var(--panel);
  color: var(--muted);
  font-size: 15px;
  line-height: 1.7;
}

.page-about .pane__list .mono {
  font-size: 16px;
  letter-spacing: 0.06em;
  min-width: 3.4em;
}

.page-about .pane__link {
  display: inline-block;
  margin-top: 22px;
  color: var(--cyan);
  text-decoration: none;
  font-size: 15px;
  letter-spacing: 0.04em;
  border-bottom: 1px solid var(--line);
  padding-bottom: 3px;
  transition: border-color 0.24s var(--ease);
}

.page-about .pane__link:hover,
.page-about .pane__link:focus-visible {
  border-bottom-color: var(--cyan);
}

/* ---------- 02 时间轴 ---------- */
.page-about .timeline {
  list-style: none;
  margin: 30px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
}

.page-about .tl-node {
  position: relative;
  padding: 20px 18px 22px;
  border: 1px solid var(--line);
  border-radius: var(--ab-radius) var(--ab-radius-alt) var(--ab-radius) var(--ab-radius-alt);
  background: var(--panel);
  transition: transform 0.32s var(--ease), border-color 0.32s var(--ease), background 0.32s var(--ease);
}

.page-about .tl-node::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 18px;
  width: 36px;
  height: 3px;
  border-radius: 3px;
  background: var(--grad-flow);
}

.page-about .tl-node:hover,
.page-about .tl-node:focus-visible {
  transform: translateY(-6px);
  border-color: var(--cyan);
  background: var(--rail);
  outline: none;
}

.page-about .tl-year {
  display: block;
  font-size: 13px;
  letter-spacing: 0.12em;
  color: var(--cyan);
}

.page-about .tl-name {
  display: block;
  margin-top: 8px;
  font-size: 19px;
  font-weight: 400;
  color: var(--ink);
}

.page-about .tl-note {
  margin: 10px 0 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
  transition: color 0.3s var(--ease);
}

.page-about .tl-node:hover .tl-note,
.page-about .tl-node:focus-visible .tl-note {
  color: var(--ink);
}

/* ---------- 03 工序 ---------- */
.page-about .steps {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
  margin-top: 26px;
}

.page-about .step {
  position: relative;
  padding: 20px 18px 22px;
  border: 1px solid var(--line);
  border-radius: var(--ab-radius-alt) var(--ab-radius) var(--ab-radius-alt) var(--ab-radius);
  background: var(--panel);
}

.page-about .step__idx {
  display: block;
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--orange);
}

.page-about .step__name {
  margin: 10px 0 0;
  font-size: 20px;
  font-weight: 400;
  color: var(--ink);
}

.page-about .step__text {
  margin: 10px 0 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 团队分工数据条 ---------- */
.page-about .team-bars {
  margin-top: 30px;
  padding: 24px 20px 26px;
  border: 1px solid var(--line);
  border-radius: var(--ab-radius);
  background: var(--panel);
}

.page-about .bars__title {
  margin: 0 0 18px;
  font-size: 13px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--cyan);
  font-weight: 600;
}

.page-about .bars {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .bar-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 3.2em;
  grid-template-areas:
    "name val"
    "track track";
  align-items: center;
  gap: 8px 12px;
}

.page-about .bar-name {
  grid-area: name;
  font-size: 14px;
  color: var(--ink);
  letter-spacing: 0.03em;
}

.page-about .bar-track {
  grid-area: track;
  display: block;
  height: 8px;
  border-radius: 999px;
  background: var(--rail);
  overflow: hidden;
}

.page-about .bar-fill {
  display: block;
  height: 100%;
  width: var(--fill, 0%);
  border-radius: 999px;
  background: var(--grad-flow);
  transition: width 0.9s var(--ease);
}

.page-about .js [data-reveal]:not(.is-visible) .bar-fill {
  width: 0;
}

.page-about .bar-val {
  grid-area: val;
  text-align: right;
  font-size: 18px;
  letter-spacing: 0.05em;
}

/* ---------- 04 质量把关 ---------- */
.page-about .qa-grid {
  margin-top: 28px;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 26px;
}

.page-about .checks {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .check {
  display: grid;
  gap: 8px;
  padding: 18px 18px 20px;
  border: 1px solid var(--line);
  border-radius: var(--ab-radius-alt);
  background: var(--panel);
}

.page-about .check__tag {
  display: inline-block;
  align-self: start;
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--orange);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 4px 12px;
}

.page-about .check__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .rhythm {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.page-about .rhythm__item {
  padding: 18px 16px;
  border-radius: var(--ab-radius-alt);
  background: var(--panel);
  border: 1px solid var(--line);
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.page-about .rhythm__num {
  font-size: 26px;
  line-height: 1;
  letter-spacing: 0.04em;
}

.page-about .rhythm__num .unit {
  font-size: 13px;
  margin-left: 4px;
  letter-spacing: 0.06em;
}

.page-about .rhythm__label {
  font-size: 13px;
  line-height: 1.6;
  color: var(--muted);
}

/* ---------- 05 合作 ---------- */
.page-about .partner-grid {
  margin-top: 28px;
}

.page-about .partner-card {
  display: flex;
  flex-direction: column;
  gap: 12px;
  border-radius: var(--ab-radius-alt) var(--ab-radius) var(--ab-radius-alt) var(--ab-radius);
}

.page-about .partner-card__num {
  font-size: 52px;
  font-weight: 300;
  line-height: 1;
  letter-spacing: 0.02em;
}

.page-about .partner-card__name {
  margin: 0;
  font-size: 17px;
  font-weight: 400;
  line-height: 1.5;
  color: var(--ink);
}

.page-about .partner-card__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .partner-card--wide {
  background: linear-gradient(135deg, var(--panel) 0%, var(--rail) 100%);
}

/* ---------- 收尾 ---------- */
.page-about .about-next {
  margin-top: 20px;
}

.page-about .next-inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 26px;
  padding: 30px 22px;
  border: 1px solid var(--line);
  border-radius: var(--ab-radius);
  background: var(--panel);
  position: relative;
  overflow: hidden;
}

.page-about .next-inner::after {
  content: "";
  position: absolute;
  right: -60px;
  top: -60px;
  width: 220px;
  height: 220px;
  border-radius: 50%;
  background: var(--grad-heat);
  opacity: 0.18;
  filter: blur(38px);
  pointer-events: none;
}

.page-about .next-title {
  margin: 12px 0 0;
  font-size: clamp(26px, 5.5vw, 38px);
  font-weight: 300;
  color: var(--ink);
  line-height: 1.2;
}

.page-about .next-text {
  margin: 14px 0 0;
  max-width: 34em;
  color: var(--muted);
  line-height: 1.8;
}

.page-about .next-links {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
  position: relative;
  z-index: 1;
}

.page-about .next-link {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 16px 18px;
  border: 1px solid var(--line);
  border-radius: var(--ab-radius-alt);
  background: var(--bg);
  text-decoration: none;
  transition: transform 0.3s var(--ease), border-color 0.3s var(--ease);
}

.page-about .next-link:hover,
.page-about .next-link:focus-visible {
  transform: translateY(-4px);
  border-color: var(--cyan);
}

.page-about .next-link__label {
  font-size: 16px;
  color: var(--ink);
  letter-spacing: 0.04em;
}

.page-about .next-link__desc {
  font-size: 13px;
  color: var(--muted);
  line-height: 1.6;
}

/* ---------- 平板 ---------- */
@media (min-width: 720px) {
  .page-about .hero-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .steps {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .timeline {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .next-links {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .bar-row {
    grid-template-columns: 9.5em minmax(0, 1fr) 3.2em;
    grid-template-areas: "name track val";
    gap: 12px;
  }
}

/* ---------- 桌面 ---------- */
@media (min-width: 1024px) {
  .page-about .hero {
    padding: 34px 0 12px;
  }

  .page-about .hero__grid {
    grid-template-columns: minmax(0, 1.2fr) minmax(0, 0.8fr);
    gap: 56px;
  }

  .page-about .hero-stats {
    margin-top: 54px;
  }

  .page-about .chap {
    grid-template-columns: 168px minmax(0, 1fr);
    gap: 52px;
    align-items: start;
  }

  .page-about .chap__aside {
    flex-direction: column;
    align-items: flex-start;
    gap: 16px;
    position: sticky;
    top: 96px;
  }

  .page-about .timeline {
    grid-template-columns: repeat(5, minmax(0, 1fr));
    gap: 10px;
  }

  .page-about .qa-grid {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    gap: 32px;
    align-items: start;
  }

  .page-about .shot--side {
    margin-top: 0;
  }

  .page-about .rhythm {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .next-inner {
    grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
    gap: 40px;
    align-items: center;
    padding: 44px 40px;
  }
}

@media (min-width: 1280px) {
  .page-about .steps {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .tl-node,
  .page-about .next-link,
  .page-about .bar-fill,
  .page-about .pane__link {
    transition: none;
  }

  .page-about .tl-node:hover,
  .page-about .tl-node:focus-visible,
  .page-about .next-link:hover,
  .page-about .next-link:focus-visible {
    transform: none;
  }
}

.page-about {
  --fill: currentColor;
}