.page-about {
  display: block;
  padding-bottom: clamp(56px, 8vw, 96px);
}

/* ---------- 章节坐标索引 ---------- */
.page-about .chapter-index {
  position: fixed;
  right: clamp(10px, 1.8vw, 26px);
  top: 50%;
  transform: translateY(-50%);
  display: none;
  flex-direction: column;
  gap: 14px;
  z-index: 20;
}

@media (min-width: 1180px) {
  .page-about .chapter-index {
    display: flex;
  }
}

.page-about .chapter-dot {
  width: 10px;
  height: 10px;
  padding: 0;
  border-radius: 50%;
  border: 1px solid var(--steel);
  background: transparent;
  cursor: pointer;
  transition: background var(--dur-fast) var(--ease), border-color var(--dur-fast) var(--ease), transform var(--dur-fast) var(--ease);
}

.page-about .chapter-dot:hover {
  border-color: var(--apple);
}

.page-about .chapter-dot.is-current {
  background: var(--apple);
  border-color: var(--apple);
  transform: scale(1.25);
}

/* ---------- 首屏框景 ---------- */
.page-about .about-hero {
  padding-top: clamp(18px, 3vw, 30px);
}

.page-about .about-hero__panel {
  position: relative;
  overflow: hidden;
  padding: clamp(26px, 4.4vw, 56px);
  background: var(--grad-cool);
  border: 1px solid var(--edge);
  border-radius: var(--r-m);
}

.page-about .about-hero__panel::after {
  content: "";
  position: absolute;
  right: -70px;
  top: -70px;
  width: 280px;
  height: 280px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(125, 242, 176, 0.15), transparent 70%);
  pointer-events: none;
}

.page-about .about-hero__eyebrow {
  margin: 0 0 18px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--apple);
}

.page-about h1 {
  margin: 0 0 22px;
  max-width: 17em;
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: clamp(28px, 5vw, 50px);
  line-height: 1.24;
  letter-spacing: -0.01em;
  color: var(--white);
}

.page-about .about-hero__lede {
  margin: 0;
  max-width: 34em;
  font-family: var(--font-sans);
  font-size: clamp(15px, 1.5vw, 18px);
  line-height: 1.8;
  color: var(--mist);
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-top: clamp(30px, 4vw, 46px);
  background: var(--edge);
  border: 1px solid var(--edge);
  border-radius: var(--r-s);
  overflow: hidden;
}

@media (min-width: 760px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

.page-about .about-stat {
  background: var(--panel);
  padding: 20px 18px 18px;
}

.page-about .about-stat__num {
  display: block;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(32px, 4.4vw, 46px);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--white);
}

.page-about .about-stat:nth-child(1) .about-stat__num { color: var(--apple); }
.page-about .about-stat:nth-child(2) .about-stat__num { color: var(--amber); }
.page-about .about-stat:nth-child(3) .about-stat__num { color: var(--apple); }
.page-about .about-stat:nth-child(4) .about-stat__num { color: var(--white); }

.page-about .about-stat__label {
  display: block;
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.5;
  letter-spacing: 0.04em;
  color: var(--mist);
}

/* ---------- 章节骨架 ---------- */
.page-about .chapter {
  padding-top: clamp(50px, 7vw, 84px);
}

.page-about .chapter__head {
  display: flex;
  align-items: baseline;
  gap: 16px;
  padding-top: 20px;
  margin-bottom: clamp(22px, 3vw, 34px);
  border-top: 1px solid var(--edge);
}

.page-about .chapter__num {
  flex: none;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.14em;
  color: var(--amber);
}

.page-about .chapter__title {
  margin: 0;
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: clamp(21px, 2.9vw, 32px);
  line-height: 1.34;
  color: var(--white);
}

.page-about .prose p {
  margin: 0 0 1.1em;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.8;
  color: var(--mist);
}

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

.page-about .about-narrow {
  max-width: 34em;
}

.page-about .about-note {
  margin-top: clamp(26px, 3.4vw, 38px);
}

.page-about .about-lead {
  gap: clamp(24px, 3.4vw, 48px);
}

/* ---------- 三层索引 ---------- */
.page-about .index-list {
  list-style: none;
  display: grid;
  gap: 12px;
  margin: clamp(24px, 3vw, 34px) 0 0;
  padding: 0;
}

@media (min-width: 860px) {
  .page-about .index-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1px;
    background: var(--edge);
    border: 1px solid var(--edge);
    border-radius: var(--r-s);
    overflow: hidden;
  }
}

.page-about .index-item {
  padding: 20px 20px 22px;
  background: var(--panel);
  border: 1px solid var(--edge);
  border-top: 2px solid var(--apple-deep);
  border-radius: var(--r-s);
}

@media (min-width: 860px) {
  .page-about .index-item {
    border: 0;
    border-top: 2px solid var(--apple-deep);
    border-radius: 0;
  }
  .page-about .index-item:nth-child(2) { border-top-color: var(--amber); }
  .page-about .index-item:nth-child(3) { border-top-color: var(--steel); }
}

.page-about .index-item__key {
  display: block;
  margin-bottom: 10px;
  color: var(--apple);
}

.page-about .index-item__name {
  margin: 0 0 10px;
  font-family: var(--font-sans);
  font-weight: 600;
  font-size: 17px;
  color: var(--white);
}

.page-about .index-item p {
  margin: 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--mist);
}

/* ---------- 赛季轨道 ---------- */
.page-about .about-track-figure {
  margin: 0 0 clamp(30px, 4vw, 46px);
}

.page-about .season-track {
  list-style: none;
  position: relative;
  display: grid;
  gap: 14px;
  margin: 0;
  padding: 0 0 0 30px;
}

.page-about .season-track::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(180deg, var(--apple-deep), var(--amber) 55%, var(--edge));
}

@media (min-width: 880px) {
  .page-about .season-track {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 20px;
    padding: 40px 0 0;
  }
  .page-about .season-track::before {
    left: 0;
    right: 0;
    top: 14px;
    bottom: auto;
    width: auto;
    height: 1px;
    background: linear-gradient(90deg, var(--apple-deep), var(--amber) 62%, var(--edge));
  }
}

.page-about .season-node {
  position: relative;
}

.page-about .season-node__dot {
  position: absolute;
  left: -30px;
  top: 18px;
  width: 15px;
  height: 15px;
  box-sizing: border-box;
  border-radius: 50%;
  background: var(--ink);
  border: 2px solid var(--apple);
  z-index: 1;
}

@media (min-width: 880px) {
  .page-about .season-node__dot {
    left: 6px;
    top: -33px;
  }
  .page-about .season-node:nth-child(2) .season-node__dot { border-color: var(--amber); }
  .page-about .season-node:nth-child(3) .season-node__dot { border-color: var(--apple); }
  .page-about .season-node:nth-child(4) .season-node__dot { border-color: var(--amber); }
}

.page-about .season-node details {
  height: 100%;
}

.page-about .season-node summary {
  display: block;
  list-style: none;
  cursor: pointer;
  padding: 16px 18px;
  background: var(--panel);
  border: 1px solid var(--edge);
  border-radius: var(--r-m);
  transition: border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .season-node summary::-webkit-details-marker {
  display: none;
}

.page-about .season-node summary::after {
  content: "▾";
  float: right;
  margin-left: 10px;
  font-size: 12px;
  color: var(--steel);
  transition: color var(--dur) var(--ease);
}

.page-about .season-node details[open] summary::after {
  content: "▴";
  color: var(--apple);
}

.page-about .season-node summary:hover {
  border-color: var(--apple-deep);
}

.page-about .season-node details[open] summary {
  border-color: var(--apple);
  border-bottom-left-radius: 0;
  border-bottom-right-radius: 0;
}

.page-about .season-node__era {
  display: block;
  margin-bottom: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--steel);
}

.page-about .season-node__title {
  display: block;
  font-family: var(--font-sans);
  font-weight: 600;
  font-size: 16px;
  line-height: 1.5;
  color: var(--white);
}

.page-about .season-node__body {
  margin-top: -1px;
  padding: 14px 18px 18px;
  background: var(--panel);
  border: 1px solid var(--apple);
  border-top: 0;
  border-radius: 0 0 var(--r-m) var(--r-m);
}

.page-about .season-node__body p {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--mist);
}

/* ---------- 左右分栏 ---------- */
.page-about .split {
  display: grid;
  gap: clamp(24px, 3.4vw, 44px);
  align-items: center;
}

@media (min-width: 900px) {
  .page-about .split {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  }
  .page-about .split--reverse .split__body {
    order: 1;
  }
  .page-about .split--reverse .split__media {
    order: 2;
  }
}

.page-about .split__media .media-frame {
  margin: 0;
}

/* ---------- 团队卡片 ---------- */
.page-about .team-grid {
  display: grid;
  gap: 12px;
  margin-top: clamp(24px, 3vw, 32px);
}

@media (min-width: 640px) {
  .page-about .team-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

.page-about .team-card {
  padding: 18px 20px;
  background: var(--panel);
  border: 1px solid var(--edge);
  border-left: 3px solid var(--apple);
  border-radius: var(--r-s);
  transition: border-color var(--dur) var(--ease);
}

.page-about .team-card:nth-child(2) { border-left-color: var(--amber); }
.page-about .team-card:nth-child(3) { border-left-color: var(--steel); }
.page-about .team-card:nth-child(4) { border-left-color: var(--apple-deep); }

.page-about .team-card:hover {
  border-top-color: var(--apple-deep);
  border-right-color: var(--apple-deep);
  border-bottom-color: var(--apple-deep);
}

.page-about .team-card__name {
  margin: 0 0 8px;
  font-family: var(--font-sans);
  font-weight: 600;
  font-size: 16px;
  color: var(--white);
}

.page-about .team-card__desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--mist);
}

/* ---------- 服务承诺 ---------- */
.page-about .promise-list {
  list-style: none;
  display: grid;
  gap: 1px;
  margin: clamp(24px, 3vw, 34px) 0 0;
  padding: 0;
  background: var(--edge);
  border: 1px solid var(--edge);
  border-radius: var(--r-s);
  overflow: hidden;
}

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

.page-about .promise-item {
  padding: 20px 22px;
  background: var(--panel);
}

.page-about .promise-item__key {
  display: block;
  margin-bottom: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--apple);
}

.page-about .promise-item__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.72;
  color: var(--white);
}

.page-about .contact-block {
  display: grid;
  gap: 8px;
  margin-top: clamp(20px, 2.6vw, 28px);
  padding: 22px 24px;
  background: var(--panel);
  border: 1px solid var(--edge);
  border-left: 3px solid var(--ember);
  border-radius: var(--r-s);
}

.page-about .contact-block__line {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 15px;
  line-height: 1.7;
  color: var(--white);
  word-break: break-word;
}

.page-about .contact-block__line .mono-label {
  display: inline-block;
  min-width: 5.5em;
  margin-right: 10px;
  color: var(--steel);
}

/* ---------- 下一步方向 ---------- */
.page-about .about-next {
  gap: 12px;
}

.page-about .next-card {
  padding: 22px 22px 24px;
  background: var(--panel);
  border: 1px solid var(--edge);
  border-top: 2px solid var(--apple-deep);
  border-radius: var(--r-s);
}

.page-about .next-card:nth-child(2) { border-top-color: var(--amber); }
.page-about .next-card:nth-child(3) { border-top-color: var(--steel); }

.page-about .next-card__name {
  margin: 0 0 10px;
  font-family: var(--font-sans);
  font-weight: 600;
  font-size: 17px;
  line-height: 1.45;
  color: var(--white);
}

.page-about .next-card__desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--mist);
}

.page-about .about-foot-links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(28px, 3.6vw, 40px);
}

/* ---------- 窄屏修正 ---------- */
@media (max-width: 559px) {
  .page-about .about-stats {
    grid-template-columns: minmax(0, 1fr);
  }
  .page-about .contact-block__line .mono-label {
    display: block;
    min-width: 0;
    margin: 0 0 2px;
  }
  .page-about .season-track {
    padding-left: 24px;
  }
  .page-about .season-node__dot {
    left: -24px;
  }
  .page-about .about-foot-links .btn {
    width: 100%;
    text-align: center;
  }
}
<<<END>>>