.page-about {
  --ab-cut: 22px;
  --ab-track: 3px;
  background: var(--yb-paper);
  color: var(--yb-ink);
  font-family: var(--yb-font-sans);
  font-size: 16px;
  line-height: 1.75;
  letter-spacing: 0;
}

.page-about .ab-layout {
  padding: clamp(20px, 3vw, 36px) 0 clamp(40px, 6vw, 80px);
}

/* ---------- 首屏主题区 ---------- */
.page-about .ab-hero {
  padding: clamp(18px, 3vw, 32px) 0 0;
}

.page-about .ab-hero__panel {
  position: relative;
  overflow: hidden;
  background: var(--yb-ink);
  color: var(--yb-paper);
  padding: clamp(26px, 4.6vw, 64px);
  clip-path: polygon(0 0, calc(100% - 40px) 0, 100% 40px, 100% 100%, 0 100%);
}

.page-about .ab-hero__panel::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: repeating-linear-gradient(12deg, rgba(247, 244, 239, .05) 0 1px, transparent 1px 15px);
  pointer-events: none;
}

.page-about .ab-hero__panel::after {
  content: "";
  position: absolute;
  top: 0;
  left: clamp(26px, 4.6vw, 64px);
  width: 66px;
  height: 5px;
  background: var(--yb-red);
}

.page-about .ab-hero__grid {
  position: relative;
  display: grid;
  gap: clamp(24px, 4vw, 48px);
  align-items: center;
}

.page-about .ab-kicker {
  margin: 0 0 14px;
  font-family: var(--yb-font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--yb-gold);
}

.page-about .ab-hero__title {
  margin: 0 0 18px;
  font-size: clamp(30px, 5.4vw, 54px);
  font-weight: 900;
  line-height: 1.14;
  letter-spacing: -.02em;
  color: var(--yb-snow);
}

.page-about .ab-hero__lede {
  margin: 0 0 30px;
  max-width: 56ch;
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.85;
  color: rgba(247, 244, 239, .78);
}

.page-about .ab-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px 20px;
  padding-top: 22px;
  border-top: 1px solid var(--yb-line-dark);
}

.page-about .ab-fact__num {
  display: block;
  font-family: var(--yb-font-mono);
  font-size: clamp(22px, 3vw, 32px);
  font-weight: 700;
  line-height: 1.1;
  color: var(--yb-gold);
}

.page-about .ab-fact__label {
  display: block;
  margin-top: 6px;
  font-size: 12.5px;
  line-height: 1.6;
  color: rgba(247, 244, 239, .62);
}

.page-about .ab-hero__figure {
  position: relative;
  margin: 0;
  background: var(--yb-char);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 26px), calc(100% - 26px) 100%, 0 100%);
}

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

.page-about .ab-hero__figure .yb-media__caption {
  display: block;
  padding: 10px 14px;
  font-family: var(--yb-font-mono);
  font-size: 11.5px;
  letter-spacing: .04em;
  color: rgba(247, 244, 239, .6);
}

/* ---------- 章节骨架 ---------- */
.page-about .ab-sec {
  padding: clamp(34px, 5vw, 68px) 0;
  border-top: 1px solid var(--yb-line);
}

.page-about .ab-sec:first-child {
  border-top: 0;
  padding-top: clamp(8px, 2vw, 16px);
}

.page-about .ab-h2 {
  margin: 0 0 16px;
  font-size: clamp(23px, 3.3vw, 34px);
  font-weight: 900;
  line-height: 1.22;
  letter-spacing: -.02em;
  color: var(--yb-ink);
}

.page-about .ab-p {
  margin: 0 0 16px;
  max-width: 66ch;
  color: var(--yb-char);
}

.page-about .ab-p--after {
  margin-top: 22px;
  color: var(--yb-muted);
  font-size: 15px;
}

.page-about .ab-link {
  display: inline-block;
  color: var(--yb-red);
  text-decoration: none;
  padding-bottom: 2px;
  background-image: linear-gradient(currentColor, currentColor);
  background-repeat: no-repeat;
  background-position: 0 100%;
  background-size: 0% 1px;
  transition: background-size var(--yb-ease), color var(--yb-ease);
}

.page-about .ab-link:hover,
.page-about .ab-link:focus-visible {
  background-size: 100% 1px;
  color: var(--yb-red-deep);
}

.page-about a:focus-visible {
  outline: 2px solid var(--yb-red);
  outline-offset: 3px;
}

/* ---------- 两个入口 ---------- */
.page-about .ab-lanes {
  display: grid;
  gap: 16px;
  margin-top: 26px;
}

.page-about .ab-lane {
  position: relative;
  padding: 26px 24px 24px 28px;
  background: var(--yb-snow);
  box-shadow: inset 0 0 0 1px var(--yb-line);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 20px), calc(100% - 20px) 100%, 0 100%);
  transition: box-shadow var(--yb-ease), transform var(--yb-ease);
}

.page-about .ab-lane::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 4px;
  background: var(--yb-red);
}

.page-about .ab-lane--gold::before {
  background: var(--yb-gold);
}

.page-about .ab-lane:hover {
  box-shadow: inset 0 0 0 1px var(--yb-red);
  transform: translateY(-2px);
}

.page-about .ab-lane__idx {
  margin: 0 0 10px;
  font-size: 11.5px;
  letter-spacing: .1em;
  color: var(--yb-muted);
}

.page-about .ab-lane__title {
  margin: 0 0 10px;
  font-size: clamp(17px, 2vw, 20px);
  font-weight: 900;
  line-height: 1.35;
  letter-spacing: -.01em;
  color: var(--yb-ink);
}

.page-about .ab-lane__text {
  margin: 0 0 18px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--yb-char);
}

/* ---------- 图片容器 ---------- */
.page-about .ab-figure {
  margin: 26px 0 0;
  background: var(--yb-char);
  clip-path: polygon(0 0, calc(100% - 24px) 0, 100% 24px, 100% 100%, 0 100%);
}

.page-about .ab-figure--inset {
  margin-top: 30px;
}

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

.page-about .ab-figure .yb-media__caption {
  display: block;
  padding: 10px 16px;
  font-family: var(--yb-font-mono);
  font-size: 11.5px;
  letter-spacing: .04em;
  color: rgba(247, 244, 239, .6);
}

/* ---------- 发展历程时间轴 ---------- */
.page-about .ab-timeline {
  position: relative;
  margin-top: 30px;
}

.page-about .ab-timeline::before {
  content: "";
  position: absolute;
  left: var(--ab-track);
  top: 0;
  bottom: 0;
  width: 1px;
  background: linear-gradient(180deg, var(--yb-gold), rgba(212, 160, 23, 0) 88%);
  opacity: .55;
}

.page-about .ab-phase {
  position: relative;
  padding: 22px 0;
  border-top: 1px solid var(--yb-line);
}

.page-about .ab-phase:first-child {
  border-top: 0;
}

.page-about .ab-phase::after {
  content: "";
  position: absolute;
  left: 0;
  top: 32px;
  width: 7px;
  height: 7px;
  background: var(--yb-gold);
  transform: rotate(45deg);
  transition: background var(--yb-ease);
}

.page-about .ab-phase:hover::after,
.page-about .ab-phase:target::after {
  background: var(--yb-red);
}

.page-about .ab-phase:target {
  background: rgba(212, 160, 23, .08);
}

.page-about .ab-phase__year {
  padding-left: 18px;
  font-family: var(--yb-font-mono);
  font-size: clamp(21px, 3vw, 28px);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: .02em;
  color: var(--yb-muted);
  transition: color var(--yb-ease);
}

.page-about .ab-phase__year a {
  color: inherit;
  text-decoration: none;
}

.page-about .ab-phase:hover .ab-phase__year,
.page-about .ab-phase:target .ab-phase__year {
  color: var(--yb-red);
}

.page-about .ab-phase__body {
  padding-left: 18px;
}

.page-about .ab-phase__title {
  margin: 8px 0 8px;
  font-size: clamp(16px, 2vw, 20px);
  font-weight: 900;
  line-height: 1.35;
  letter-spacing: -.01em;
  color: var(--yb-ink);
}

.page-about .ab-phase__text {
  margin: 0;
  max-width: 60ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--yb-char);
}

/* ---------- 团队 ---------- */
.page-about .ab-roles {
  display: grid;
  gap: 14px;
  margin-top: 26px;
}

.page-about .ab-role {
  position: relative;
  padding: 22px 20px;
  background: var(--yb-ink);
  color: var(--yb-paper);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 16px), calc(100% - 16px) 100%, 0 100%);
}

.page-about .ab-role--gold {
  background: var(--yb-char);
}

.page-about .ab-role__num {
  display: block;
  font-family: var(--yb-font-mono);
  font-size: clamp(30px, 4vw, 38px);
  font-weight: 700;
  line-height: 1;
  color: var(--yb-gold);
}

.page-about .ab-role--gold .ab-role__num {
  color: var(--yb-gold-soft);
}

.page-about .ab-role__name {
  margin: 12px 0 6px;
  font-size: 16px;
  font-weight: 900;
  letter-spacing: -.01em;
  color: var(--yb-snow);
}

.page-about .ab-role__desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: rgba(247, 244, 239, .7);
}

.page-about .ab-flow {
  margin-top: 30px;
  border-top: 1px solid var(--yb-line);
}

.page-about .ab-flow__step {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: 12px;
  align-items: start;
  padding: 16px 0;
  border-bottom: 1px solid var(--yb-line);
}

.page-about .ab-flow__idx {
  padding-top: 4px;
  font-size: 12.5px;
  letter-spacing: .08em;
  color: var(--yb-red);
}

.page-about .ab-flow__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--yb-char);
}

.page-about .ab-flow__text strong {
  font-weight: 900;
  color: var(--yb-ink);
}

/* ---------- 合作与备案 ---------- */
.page-about .ab-partners {
  display: grid;
  gap: 16px;
  margin-top: 26px;
}

.page-about .ab-partner {
  padding: 24px;
  background: var(--yb-snow);
  box-shadow: inset 0 0 0 1px var(--yb-line);
  border-left: 4px solid var(--yb-red);
  transition: box-shadow var(--yb-ease), transform var(--yb-ease);
}

.page-about .ab-partner--gold {
  border-left-color: var(--yb-gold);
}

.page-about .ab-partner:hover {
  box-shadow: inset 0 0 0 1px var(--yb-red);
  transform: translateY(-2px);
}

.page-about .ab-partner__num {
  display: block;
  font-family: var(--yb-font-mono);
  font-size: clamp(30px, 4vw, 42px);
  font-weight: 700;
  line-height: 1;
  color: var(--yb-ink);
}

.page-about .ab-partner__name {
  margin: 12px 0 8px;
  font-size: 16px;
  font-weight: 900;
  letter-spacing: -.01em;
  color: var(--yb-ink);
}

.page-about .ab-partner__text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--yb-char);
}

.page-about .ab-legal {
  margin-top: 22px;
  padding: 18px 20px;
  background: rgba(240, 214, 138, .22);
  border-left: 4px solid var(--yb-gold);
}

.page-about .ab-legal__line {
  margin: 0 0 10px;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--yb-char);
}

.page-about .ab-legal__line:last-child {
  margin-bottom: 0;
}

.page-about .ab-legal__line strong {
  font-weight: 900;
  color: var(--yb-ink);
}

/* ---------- 覆盖与节奏 ---------- */
.page-about .ab-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-top: 26px;
  background: var(--yb-slate);
  clip-path: polygon(0 0, calc(100% - 24px) 0, 100% 24px, 100% 100%, 0 100%);
  overflow: hidden;
}

.page-about .ab-stat {
  padding: 22px 18px 20px;
  background: var(--yb-ink);
}

.page-about .ab-stat:nth-child(2n) {
  background: var(--yb-char);
}

.page-about .ab-stat__num {
  display: block;
  font-family: var(--yb-font-mono);
  font-size: clamp(24px, 3.6vw, 36px);
  font-weight: 700;
  line-height: 1.1;
  color: var(--yb-gold);
}

.page-about .ab-stat__label {
  display: block;
  margin-top: 8px;
  font-size: 14px;
  font-weight: 700;
  color: var(--yb-snow);
}

.page-about .ab-stat__note {
  display: block;
  margin-top: 5px;
  font-size: 12.5px;
  line-height: 1.6;
  color: rgba(247, 244, 239, .58);
}

/* ---------- 分隔色带与结尾 ---------- */
.page-about .ab-band {
  height: 6px;
  background: repeating-linear-gradient(12deg, var(--yb-red) 0 10px, var(--yb-gold) 10px 20px, var(--yb-green) 20px 30px, var(--yb-blue) 30px 40px, var(--yb-snow) 40px 50px);
  opacity: .85;
}

.page-about .ab-cta {
  padding: clamp(36px, 5vw, 72px) 0 clamp(48px, 7vw, 96px);
  background: var(--yb-paper);
}

.page-about .ab-cta__panel {
  display: grid;
  gap: 24px;
  padding: clamp(24px, 4vw, 44px);
  background: var(--yb-ink);
  color: var(--yb-paper);
  clip-path: polygon(0 0, calc(100% - 34px) 0, 100% 34px, 100% 100%, 0 100%);
}

.page-about .ab-cta__title {
  margin: 0 0 12px;
  font-size: clamp(22px, 3vw, 30px);
  font-weight: 900;
  line-height: 1.24;
  letter-spacing: -.02em;
  color: var(--yb-snow);
}

.page-about .ab-cta__text {
  margin: 0;
  max-width: 58ch;
  font-size: 15px;
  line-height: 1.8;
  color: rgba(247, 244, 239, .74);
}

.page-about .ab-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* ---------- 断点 ---------- */
@media (min-width: 620px) {
  .page-about .ab-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 760px) {
  .page-about .ab-lanes {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 22px;
  }

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

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

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

  .page-about .ab-phase {
    display: grid;
    grid-template-columns: 104px minmax(0, 1fr);
    gap: 34px;
    align-items: start;
    padding: 26px 0;
  }

  .page-about .ab-phase::after {
    top: 36px;
  }

  .page-about .ab-phase__body {
    padding-left: 0;
  }

  .page-about .ab-phase__title {
    margin-top: 0;
  }
}

@media (min-width: 900px) {
  .page-about .ab-hero__grid {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, .92fr);
  }

  .page-about .ab-cta__panel {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
  }

  .page-about .ab-flow {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: 34px;
  }
}

@media (min-width: 1120px) {
  .page-about .ab-hero__figure {
    margin-left: auto;
  }

  .page-about .ab-phase {
    grid-template-columns: 120px minmax(0, 1fr);
    gap: 46px;
  }
}