.page-about {
  --about-rail: 168px;
  --about-line: rgba(28, 28, 30, 0.12);
  background: var(--cream);
  color: var(--ink);
  overflow-x: hidden;
}

/* ---------- 首屏：时间走廊 ---------- */
.page-about .about-hero {
  padding: 16px 0 40px;
}

.page-about .about-hero__grid {
  display: grid;
  gap: 22px;
}

.page-about .about-hero__rail {
  border-top: 2px solid var(--ink);
  padding-top: 10px;
}

.page-about .about-hero__rail-title {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.2em;
  color: var(--moss);
}

.page-about .yearscale {
  list-style: none;
  margin: 0;
  padding: 0 0 4px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .yearscale__item {
  flex: 0 0 auto;
}

.page-about .yearscale__link {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 7px 12px;
  border: 1px solid var(--bran);
  background: var(--white);
  color: var(--ink);
  text-decoration: none;
  white-space: nowrap;
  transition: border-color 0.2s var(--ease), background 0.2s var(--ease), transform 0.2s var(--ease);
}

.page-about .yearscale__year {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 14px;
  color: var(--green);
}

.page-about .yearscale__txt {
  font-size: 11px;
  color: var(--moss);
}

.page-about .yearscale__link:hover,
.page-about .yearscale__link:focus-visible {
  border-color: var(--orange);
  background: var(--bran);
  transform: translateY(-2px);
}

.page-about .eyebrow {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--brick);
}

.page-about .about-hero__title {
  margin: 0 0 16px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(2rem, 8vw, 3.6rem);
  line-height: 1.02;
  letter-spacing: -0.01em;
}

.page-about .about-hero__lead {
  margin: 0;
  font-size: 16px;
  line-height: 1.8;
  max-width: 40ch;
  color: var(--ink);
}

.page-about .about-hero__meta {
  margin: 16px 0 0;
  display: inline-block;
  padding: 8px 12px;
  border-left: 4px solid var(--orange);
  background: var(--bran);
  font-size: 12px;
  line-height: 1.7;
  color: var(--ink);
}

.page-about .about-hero__meta .num {
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--green);
}

.page-about .about-hero__figure {
  margin: 24px 0 0;
  border: 1px solid var(--bran);
  background: var(--bran);
  box-shadow: var(--shadow-hard);
}

.page-about .about-hero__figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  aspect-ratio: 14 / 9;
}

.page-about .about-hero__cap {
  padding: 8px 12px;
  font-size: 12px;
  line-height: 1.6;
  color: var(--moss);
  border-top: 1px solid var(--bran);
}

/* ---------- 通用区块 ---------- */
.page-about .about-section {
  padding: 40px 0;
}

.page-about .about-section--tint {
  background: var(--bran);
  border-top: 1px solid var(--about-line);
  border-bottom: 1px solid var(--about-line);
}

.page-about .sec-head {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding-bottom: 10px;
  margin-bottom: 22px;
  border-bottom: 2px solid var(--ink);
}

.page-about .sec-head__no {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 12px;
  color: var(--orange);
  letter-spacing: 0.06em;
}

.page-about .sec-head h2 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.35rem, 5.4vw, 2.1rem);
  line-height: 1.1;
  letter-spacing: -0.01em;
}

.page-about .sec-head--dark {
  border-bottom-color: rgba(250, 245, 234, 0.4);
}

.page-about .sec-head--dark h2 {
  color: var(--cream);
}

/* ---------- 起点 ---------- */
.page-about .start-grid {
  display: grid;
  gap: 20px;
}

.page-about .start__big {
  margin: 0;
  padding-left: 14px;
  border-left: 4px solid var(--green);
  font-size: 18px;
  font-weight: 700;
  line-height: 1.65;
  color: var(--green-deep);
}

.page-about .start__body p {
  margin: 0 0 14px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink);
}

.page-about .start__body p:last-child {
  margin-bottom: 0;
}

/* ---------- 比赛日运转 ---------- */
.page-about .shift {
  display: grid;
  gap: 24px;
}

.page-about .shift__figure {
  margin: 0;
  border: 1px solid rgba(28, 28, 30, 0.14);
  background: var(--white);
  box-shadow: var(--shadow-hard);
}

.page-about .shift__figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  aspect-ratio: 4 / 3;
}

.page-about .shift__cap {
  padding: 8px 12px;
  font-size: 12px;
  line-height: 1.6;
  color: var(--moss);
  border-top: 1px solid var(--bran);
}

.page-about .shift__steps {
  list-style: none;
  margin: 0;
  padding: 0 0 0 22px;
  border-left: 2px solid rgba(11, 110, 79, 0.35);
  display: grid;
  gap: 18px;
}

.page-about .shift__step {
  position: relative;
}

.page-about .shift__step::before {
  content: "";
  position: absolute;
  left: -28px;
  top: 6px;
  width: 10px;
  height: 10px;
  background: var(--orange);
  box-shadow: 0 0 0 3px var(--bran);
}

.page-about .shift__time {
  display: block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--green);
  margin-bottom: 4px;
}

.page-about .shift__step p {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--ink);
}

.page-about .roster {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .roster__item {
  display: grid;
  grid-template-columns: auto 1fr;
  grid-template-areas: "num name" "num desc";
  gap: 0 12px;
  padding: 12px 14px;
  background: var(--white);
  border: 1px solid rgba(28, 28, 30, 0.14);
  border-top: 3px solid var(--green);
}

.page-about .roster__num {
  grid-area: num;
  align-self: center;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 28px;
  line-height: 1;
  color: var(--green);
}

.page-about .roster__name {
  grid-area: name;
  font-size: 14px;
  font-weight: 700;
}

.page-about .roster__desc {
  grid-area: desc;
  font-size: 12px;
  line-height: 1.6;
  color: var(--moss);
}

/* ---------- 里程碑档案卡 ---------- */
.page-about .mile-intro {
  margin: 0 0 20px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink);
  max-width: 44ch;
}

.page-about .milestone {
  background: var(--white);
  border: 1px solid rgba(28, 28, 30, 0.16);
  border-left: 6px solid var(--green);
  box-shadow: var(--shadow-hard);
  margin-bottom: 14px;
  transition: box-shadow 0.2s var(--ease), transform 0.2s var(--ease);
}

.page-about .milestone:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lift);
}

.page-about .milestone[open] {
  border-left-color: var(--orange);
}

.page-about .milestone__head {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 16px;
  cursor: pointer;
  list-style: none;
}

.page-about .milestone__head::-webkit-details-marker {
  display: none;
}

.page-about .milestone__head:focus-visible {
  outline: 2px solid var(--orange);
  outline-offset: 2px;
}

.page-about .milestone__year {
  flex: 0 0 auto;
  min-width: 58px;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 15px;
  color: var(--green-deep);
}

.page-about .milestone__title {
  flex: 1 1 auto;
  font-size: 15px;
  font-weight: 700;
  line-height: 1.45;
}

.page-about .milestone__hint {
  flex: 0 0 auto;
  width: 24px;
  height: 24px;
  display: grid;
  place-items: center;
  background: var(--bran);
  color: var(--ink);
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 700;
  line-height: 1;
}

.page-about .milestone__hint::before {
  content: "+";
}

.page-about .milestone[open] .milestone__hint::before {
  content: "−";
}

.page-about .milestone[open] .milestone__hint {
  background: var(--orange);
}

.page-about .milestone__body {
  padding: 0 16px 16px;
  border-top: 1px dashed rgba(28, 28, 30, 0.16);
  padding-top: 12px;
}

.page-about .milestone__body p {
  margin: 0 0 10px;
  font-size: 14px;
  line-height: 1.8;
  color: var(--ink);
}

.page-about .milestone__list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 6px;
}

.page-about .milestone__list li {
  position: relative;
  padding-left: 16px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--moss);
}

.page-about .milestone__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 9px;
  width: 6px;
  height: 6px;
  background: var(--blue);
}

.page-about .mile-figure {
  margin: 24px 0 0;
  border: 1px solid rgba(28, 28, 30, 0.14);
  background: var(--white);
}

.page-about .mile-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  aspect-ratio: 3 / 2;
}

.page-about .mile-figure__cap {
  padding: 10px 14px;
  font-size: 12px;
  line-height: 1.6;
  color: var(--moss);
  border-top: 1px solid var(--bran);
}

/* ---------- 档案规模 ---------- */
.page-about .archive {
  background: var(--green-deep);
  color: var(--cream);
  padding: 64px 0 48px;
  margin-top: 36px;
  clip-path: polygon(0 32px, 100% 0, 100% 100%, 0 100%);
}

.page-about .archive__lead {
  margin: 0 0 24px;
  font-size: 15px;
  line-height: 1.8;
  color: rgba(250, 245, 234, 0.86);
  max-width: 42ch;
}

.page-about .stats {
  list-style: none;
  margin: 0 0 32px;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: rgba(250, 245, 234, 0.22);
  border: 1px solid rgba(250, 245, 234, 0.22);
}

.page-about .stat {
  padding: 16px 14px;
  background: var(--green-deep);
}

.page-about .stat__num {
  display: block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(1.5rem, 7vw, 2.3rem);
  line-height: 1;
  letter-spacing: 0.01em;
  color: var(--cream);
}

.page-about .stat__plus {
  font-size: 12px;
  font-weight: 600;
  color: var(--orange);
  margin-left: 4px;
  letter-spacing: 0;
}

.page-about .stat__label {
  display: block;
  margin-top: 8px;
  font-size: 12px;
  line-height: 1.6;
  color: rgba(250, 245, 234, 0.72);
}

.page-about .archbars__title {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--orange);
}

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

.page-about .archbar {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr) 28px;
  align-items: center;
  gap: 10px;
}

.page-about .archbar__label {
  font-size: 13px;
  color: rgba(250, 245, 234, 0.88);
}

.page-about .archbar__track {
  display: block;
  height: 10px;
  background: rgba(250, 245, 234, 0.16);
  border: 1px solid rgba(250, 245, 234, 0.28);
}

.page-about .archbar__fill {
  display: block;
  height: 100%;
  background: var(--blue);
}

.page-about .archbar__fill--lead {
  background: var(--orange);
}

.page-about .archbar__num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 13px;
  text-align: right;
  color: var(--cream);
}

.page-about .archbars__note {
  margin: 14px 0 0;
  font-size: 12px;
  line-height: 1.7;
  color: rgba(250, 245, 234, 0.66);
}

.page-about .archive__extra {
  margin: 24px 0 0;
  padding-top: 16px;
  border-top: 1px solid rgba(250, 245, 234, 0.22);
  font-size: 13px;
  line-height: 1.8;
  color: rgba(250, 245, 234, 0.8);
  max-width: 52ch;
}

/* ---------- 合作生态 ---------- */
.page-about .partner__intro {
  margin: 0 0 20px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink);
  max-width: 44ch;
}

.page-about .partner-grid {
  display: grid;
  gap: 14px;
}

.page-about .partner {
  position: relative;
  padding: 18px 16px 16px;
  background: var(--white);
  border: 1px solid rgba(28, 28, 30, 0.14);
  box-shadow: var(--shadow-hard);
  transition: transform 0.2s var(--ease), box-shadow 0.2s var(--ease);
}

.page-about .partner:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lift);
}

.page-about .partner__num {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 20px;
  color: var(--green);
}

.page-about .partner__title {
  margin: 0 0 8px;
  font-size: 16px;
  font-weight: 700;
  line-height: 1.4;
}

.page-about .partner__text {
  margin: 0 0 14px;
  font-size: 13px;
  line-height: 1.78;
  color: var(--ink);
}

.page-about .partner .tag {
  display: inline-block;
  padding: 3px 8px;
  font-size: 11px;
  letter-spacing: 0.06em;
  background: var(--blue);
  color: var(--white);
}

.page-about .partner .tag--orange {
  background: var(--orange);
  color: var(--ink);
}

/* ---------- 编辑做法 ---------- */
.page-about .rule-grid {
  display: grid;
  gap: 22px;
}

.page-about .rule-grid__main p {
  margin: 0 0 14px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink);
}

.page-about .rule-grid__main p:last-child {
  margin-bottom: 0;
}

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

.page-about .rule-list__item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  align-items: baseline;
  gap: 10px;
  padding: 10px 12px;
  background: var(--white);
  border-left: 3px solid var(--blue);
  font-size: 13px;
  line-height: 1.7;
}

.page-about .rule-list__no {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 12px;
  color: var(--brick);
}

/* ---------- 下一步 ---------- */
.page-about .next__lead {
  margin: 0 0 22px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--ink);
  max-width: 52ch;
}

.page-about .next-cta {
  display: grid;
  gap: 16px;
  padding: 18px 16px;
  background: var(--white);
  border: 1px solid rgba(28, 28, 30, 0.16);
  border-top: 5px solid var(--green);
  box-shadow: var(--shadow-hard);
}

.page-about .next-cta__title {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 700;
  line-height: 1.4;
}

.page-about .next-cta__desc {
  margin: 0;
  font-size: 13px;
  line-height: 1.75;
  color: var(--moss);
}

.page-about .next-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.page-about .next-cta__actions .btn {
  flex: 1 1 auto;
  min-width: 132px;
  text-align: center;
  text-decoration: none;
}

/* ---------- 平板与桌面 ---------- */
@media (min-width: 768px) {
  .page-about .about-hero {
    padding: 24px 0 56px;
  }

  .page-about .start-grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: 32px;
  }

  .page-about .start__big {
    font-size: 20px;
  }

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

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

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

  .page-about .rule-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 32px;
  }

  .page-about .next-cta {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    padding: 22px 24px;
  }

  .page-about .next-cta__actions {
    flex-wrap: nowrap;
  }

  .page-about .next-cta__actions .btn {
    flex: 0 0 auto;
    min-width: 0;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: 44px;
    align-items: start;
  }

  .page-about .about-hero__rail {
    position: sticky;
    top: calc(var(--header-h) + 24px);
  }

  .page-about .yearscale {
    display: flex;
    flex-direction: column;
    gap: 0;
    overflow: visible;
  }

  .page-about .yearscale__item {
    flex: none;
  }

  .page-about .yearscale__link {
    flex-direction: column;
    align-items: flex-start;
    gap: 2px;
    white-space: normal;
    padding: 10px 0 10px 14px;
    border: none;
    border-left: 2px solid var(--bran);
    background: transparent;
  }

  .page-about .yearscale__year {
    font-size: 20px;
    line-height: 1.1;
  }

  .page-about .yearscale__link:hover,
  .page-about .yearscale__link:focus-visible {
    background: transparent;
    border-left-color: var(--orange);
    transform: none;
  }

  .page-about .yearscale__link:hover .yearscale__year,
  .page-about .yearscale__link:focus-visible .yearscale__year {
    color: var(--brick);
  }

  .page-about .about-hero__lead {
    font-size: 17px;
    max-width: 42ch;
  }

  .page-about .shift {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: 40px;
    align-items: start;
  }

  .page-about .milestone__head {
    padding: 18px 22px;
  }

  .page-about .milestone__title {
    font-size: 17px;
  }

  .page-about .milestone__body {
    padding: 14px 22px 20px;
  }

  .page-about .archive {
    padding: 88px 0 64px;
    clip-path: polygon(0 48px, 100% 0, 100% 100%, 0 100%);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .yearscale__link,
  .page-about .milestone,
  .page-about .partner {
    transition: none;
  }

  .page-about .yearscale__link:hover,
  .page-about .milestone:hover,
  .page-about .partner:hover {
    transform: none;
  }
}