.page-about {
  --pa-cut: 16px;
  --pa-pad: clamp(18px, 3.2vw, 40px);
  --pa-rhythm: clamp(46px, 7vw, 96px);
}

/* ===================== 首屏 ===================== */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(26px, 5vw, 62px) 0 clamp(32px, 5vw, 70px);
  border-bottom: 1px solid var(--line);
  background:
    radial-gradient(115% 88% at 90% -12%, rgba(255, 106, 31, 0.18), rgba(255, 106, 31, 0) 62%),
    radial-gradient(80% 60% at 6% 108%, rgba(60, 134, 245, 0.14), rgba(60, 134, 245, 0) 68%),
    linear-gradient(180deg, rgba(6, 18, 14, 0.92), rgba(11, 31, 25, 1) 82%);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  right: -70px;
  bottom: -120px;
  width: 260px;
  height: 260px;
  border: 1px dashed var(--line-strong);
  border-radius: 50%;
  opacity: 0.55;
  pointer-events: none;
}

.page-about .about-hero .wrap {
  position: relative;
  z-index: 1;
}

.page-about .about-hero h1 {
  margin: 12px 0 0;
  font-family: var(--font-display);
  font-size: clamp(34px, 7.2vw, 70px);
  line-height: 1.02;
  letter-spacing: -0.012em;
  color: var(--ivory);
  max-width: 16ch;
}

.page-about .about-hero__sub {
  margin: 12px 0 0;
  font-family: var(--font-display);
  font-size: clamp(15px, 2.4vw, 20px);
  letter-spacing: 0.05em;
  color: var(--lime);
}

.page-about .about-hero__lede {
  margin: 20px 0 0;
  max-width: 38em;
  font-size: 16.5px;
  line-height: 1.78;
  color: rgba(255, 247, 232, 0.82);
}

/* 首屏数字条 */
.page-about .hero-figures {
  margin: clamp(26px, 4vw, 46px) 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 20px), calc(100% - 20px) 100%, 0 100%);
}

.page-about .hero-figure {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 16px 16px 18px;
  background: rgba(6, 18, 14, 0.88);
}

.page-about .hero-figure__value {
  font-family: var(--font-mono);
  font-size: clamp(30px, 6vw, 46px);
  line-height: 1;
  color: var(--orange);
  text-shadow: var(--glow-orange);
  letter-spacing: 0.02em;
}

.page-about .hero-figure__label {
  font-size: 12.5px;
  letter-spacing: 0.1em;
  color: var(--grey);
}

/* ===================== 两栏骨架 ===================== */
.page-about .about-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 4vw, 52px);
  padding: clamp(34px, 5vw, 64px) 0 clamp(56px, 8vw, 110px);
}

/* 章节轨道 */
.page-about .chap-rail {
  display: none;
}

.page-about .chap-rail__title {
  margin: 0 0 12px;
  font-size: 11.5px;
  letter-spacing: 0.22em;
  color: var(--grey);
}

.page-about .chap-list {
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: chap;
}

.page-about .chap-list li {
  counter-increment: chap;
}

.page-about .chap-link {
  display: grid;
  grid-template-columns: 32px minmax(0, 1fr);
  align-items: baseline;
  gap: 4px;
  padding: 10px 0 10px 12px;
  border-left: 2px solid var(--line);
  color: var(--grey);
  font-size: 13px;
  letter-spacing: 0.05em;
  text-decoration: none;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.page-about .chap-link::before {
  content: counter(chap, decimal-leading-zero);
  font-family: var(--font-mono);
  font-size: 13px;
  color: inherit;
}

.page-about .chap-link:hover,
.page-about .chap-link:focus-visible {
  color: var(--ivory);
  border-left-color: var(--orange);
}

.page-about .chap-link__label {
  display: block;
}

@media (min-width: 1080px) {
  .page-about .about-shell {
    grid-template-columns: 146px minmax(0, 1fr);
  }

  .page-about .chap-rail {
    display: block;
    align-self: start;
    position: sticky;
    top: clamp(24px, 8vh, 90px);
  }
}

/* ===================== 章节通用 ===================== */
.page-about .about-body {
  min-width: 0;
}

.page-about .about-sec {
  position: relative;
  padding: var(--pa-rhythm) 0;
}

.page-about .about-sec:first-child {
  padding-top: clamp(6px, 2vw, 20px);
}

.page-about .about-sec + .about-sec {
  border-top: 1px solid var(--line);
}

.page-about .sec-head {
  margin-bottom: clamp(16px, 2.6vw, 26px);
}

.page-about .sec-head__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.24em;
  color: var(--orange);
}

.page-about .sec-head h2 {
  margin: 8px 0 0;
  font-family: var(--font-display);
  font-size: clamp(25px, 4.4vw, 42px);
  line-height: 1.08;
  letter-spacing: -0.005em;
  color: var(--ivory);
  max-width: 20ch;
}

.page-about .sec-lede {
  margin: 0 0 clamp(22px, 3.4vw, 36px);
  max-width: 36em;
  font-size: 16px;
  line-height: 1.78;
  color: rgba(255, 247, 232, 0.78);
}

/* ===================== 01 品牌与命名 ===================== */
.page-about .naming-grid {
  display: grid;
  gap: clamp(24px, 4vw, 42px);
}

.page-about .naming-copy p {
  margin: 0 0 16px;
  max-width: 36em;
  font-size: 16px;
  line-height: 1.78;
  color: rgba(255, 247, 232, 0.8);
}

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

.page-about .pull-quote {
  margin: 0 0 22px;
  padding: 18px 20px 18px 22px;
  border-left: 3px solid var(--orange);
  background: rgba(6, 18, 14, 0.72);
  font-family: var(--font-display);
  font-size: clamp(18px, 2.6vw, 24px);
  line-height: 1.5;
  letter-spacing: 0.01em;
  color: var(--ivory);
}

/* 图片框 */
.page-about .figframe {
  position: relative;
  margin: clamp(24px, 4vw, 44px) 0 0;
  overflow: hidden;
  border: 1px solid var(--line);
  background: var(--deep);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 22px), calc(100% - 22px) 100%, 0 100%);
}

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

.page-about .figframe--naming {
  margin-top: 0;
  aspect-ratio: 3 / 2;
}

.page-about .figframe--wide {
  aspect-ratio: 2 / 1;
}

.page-about .figframe--square {
  aspect-ratio: 1 / 1;
  max-width: 520px;
}

.page-about .figframe__cap {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 26px 16px 14px;
  font-size: 12.5px;
  letter-spacing: 0.05em;
  color: rgba(255, 247, 232, 0.86);
  background: linear-gradient(180deg, rgba(6, 18, 14, 0), rgba(6, 18, 14, 0.88));
}

@media (min-width: 900px) {
  .page-about .naming-grid {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    align-items: start;
  }

  .page-about .figframe--naming {
    aspect-ratio: 3 / 4;
    margin-top: 4px;
  }
}

/* ===================== 02 版本时间线 ===================== */
.page-about .ver-track {
  position: relative;
  margin: 0;
  padding: 0 0 0 26px;
  list-style: none;
  display: grid;
  gap: 16px;
}

.page-about .ver-track::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 12px;
  bottom: 12px;
  border-left: 2px dashed var(--line-strong);
}

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

.page-about .ver-node::before {
  content: "";
  position: absolute;
  left: -20px;
  top: 24px;
  width: 11px;
  height: 11px;
  transform: rotate(45deg);
  background: var(--grey);
  box-shadow: 0 0 0 3px var(--pitch);
}

.page-about .ver-node:last-child::before {
  background: var(--lime);
  box-shadow: 0 0 0 3px var(--pitch), var(--glow-lime);
}

.page-about .ver-card {
  padding: 16px 18px 18px;
  border: 1px solid var(--line);
  background: rgba(6, 18, 14, 0.72);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 16px), calc(100% - 16px) 100%, 0 100%);
  transition: transform 0.2s var(--ease), border-color 0.2s var(--ease);
}

.page-about .ver-card:hover {
  transform: translateY(-4px);
  border-color: var(--line-strong);
}

.page-about .ver-card--now {
  border-color: rgba(255, 106, 31, 0.5);
  background: linear-gradient(160deg, rgba(255, 106, 31, 0.1), rgba(6, 18, 14, 0.86) 62%);
}

.page-about .ver-card__ver {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 26px;
  line-height: 1;
  letter-spacing: 0.04em;
  color: var(--orange);
  text-shadow: var(--glow-orange);
}

.page-about .ver-card__year {
  margin: 6px 0 0;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.16em;
  color: var(--grey);
}

.page-about .ver-card__title {
  margin: 12px 0 8px;
  font-family: var(--font-display);
  font-size: 20px;
  line-height: 1.2;
  color: var(--ivory);
}

.page-about .ver-card__text {
  margin: 0 0 12px;
  font-size: 14.5px;
  line-height: 1.72;
  color: rgba(255, 247, 232, 0.74);
}

.page-about .ver-more {
  margin-top: 4px;
}

@media (min-width: 980px) {
  .page-about .ver-track {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 18px;
    padding: 34px 0 0;
  }

  .page-about .ver-track::before {
    left: 0;
    right: 0;
    top: 16px;
    bottom: auto;
    border-left: 0;
    border-top: 2px dashed var(--line-strong);
  }

  .page-about .ver-node::before {
    left: 0;
    top: -24px;
  }
}

/* ===================== 03 团队 ===================== */
.page-about .team-grid {
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  grid-template-columns: minmax(0, 1fr);
  margin-bottom: clamp(24px, 4vw, 40px);
}

.page-about .team-card {
  padding: 20px 18px 22px;
  background: rgba(6, 18, 14, 0.84);
}

.page-about .team-card__value {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(44px, 8vw, 74px);
  line-height: 0.95;
  letter-spacing: 0.01em;
  color: var(--ivory);
}

.page-about .team-card__unit {
  font-size: 0.34em;
  letter-spacing: 0.12em;
  color: var(--grey);
  margin-left: 8px;
}

.page-about .team-card__title {
  margin: 12px 0 6px;
  font-family: var(--font-display);
  font-size: 17px;
  letter-spacing: 0.04em;
  color: var(--lime);
}

.page-about .team-card__text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.7;
  color: rgba(255, 247, 232, 0.72);
}

.page-about .shift-band {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
}

.page-about .shift-band__cell {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 14px 16px 16px;
  border: 1px solid var(--line);
  background: rgba(11, 31, 25, 0.6);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 12px), calc(100% - 12px) 100%, 0 100%);
}

.page-about .shift-band__time {
  font-family: var(--font-mono);
  font-size: 15px;
  letter-spacing: 0.04em;
  color: var(--blue);
}

.page-about .shift-band__name {
  font-family: var(--font-display);
  font-size: 17px;
  letter-spacing: 0.08em;
  color: var(--ivory);
}

.page-about .shift-band__desc {
  font-size: 13px;
  line-height: 1.62;
  color: var(--grey);
}

.page-about .shift-note {
  margin: 18px 0 0;
  max-width: 40em;
  padding-left: 16px;
  border-left: 2px solid var(--orange);
  font-size: 15px;
  line-height: 1.76;
  color: rgba(255, 247, 232, 0.76);
}

@media (min-width: 720px) {
  .page-about .team-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

/* ===================== 04 流程 ===================== */
.page-about .flow-scroll {
  overflow-x: auto;
  padding-bottom: 8px;
  margin-bottom: clamp(20px, 3vw, 30px);
}

.page-about .flow-svg {
  display: block;
  width: 100%;
  min-width: 520px;
  height: auto;
}

.page-about .flow-svg .fn {
  fill: rgba(6, 18, 14, 0.82);
  stroke: rgba(143, 163, 155, 0.45);
  stroke-width: 1.5;
}

.page-about .flow-svg .fn--live {
  fill: rgba(255, 106, 31, 0.16);
  stroke: rgba(255, 106, 31, 0.78);
}

.page-about .flow-svg .fa {
  stroke: #3c86f5;
  stroke-width: 1.6;
  stroke-dasharray: 6 5;
}

.page-about .flow-svg .fl {
  fill: #fff7e8;
  font-family: var(--font-mono);
  font-size: 21px;
  letter-spacing: 0.06em;
}

.page-about .flow-svg .fl--live {
  fill: #ff6a1f;
}

.page-about .flow-steps {
  margin: 0 0 clamp(26px, 4vw, 42px);
  padding: 0;
  list-style: none;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  grid-template-columns: minmax(0, 1fr);
}

.page-about .flow-step {
  padding: 16px 18px 18px;
  background: rgba(6, 18, 14, 0.82);
}

.page-about .flow-step h3 {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-size: 17px;
  letter-spacing: 0.08em;
  color: var(--orange);
}

.page-about .flow-step p {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: rgba(255, 247, 232, 0.74);
}

.page-about .flow-figures {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  margin-bottom: clamp(24px, 4vw, 40px);
}

.page-about .flow-figure {
  padding: 16px 18px 18px;
  background: rgba(11, 31, 25, 0.62);
}

.page-about .flow-figure__value {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(34px, 6vw, 52px);
  line-height: 1;
  color: var(--lime);
  text-shadow: var(--glow-lime);
}

.page-about .flow-figure__unit {
  font-size: 0.36em;
  letter-spacing: 0.1em;
  margin-left: 8px;
  color: var(--grey);
}

.page-about .flow-figure__label {
  margin: 8px 0 0;
  font-size: 12.5px;
  letter-spacing: 0.1em;
  color: var(--grey);
}

@media (min-width: 720px) {
  .page-about .flow-steps {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

@media (min-width: 1080px) {
  .page-about .flow-steps {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* ===================== 05 奶油底章节 ===================== */
.page-about .about-sec--cream {
  margin: clamp(24px, 4vw, 52px) 0;
  padding: clamp(28px, 4.4vw, 52px) var(--pa-pad) clamp(30px, 4.6vw, 56px);
  background: var(--cream);
  color: var(--brown);
  border-top: 0;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 26px), calc(100% - 26px) 100%, 0 100%);
}

.page-about .about-sec--cream + .about-sec {
  border-top: 0;
}

.page-about .sec-head--ink .sec-head__num {
  color: #c2510f;
}

.page-about .sec-head--ink h2 {
  color: var(--brown);
}

.page-about .cream-lede {
  margin: 0 0 clamp(20px, 3vw, 32px);
  max-width: 36em;
  font-size: 16px;
  line-height: 1.78;
  color: rgba(26, 19, 16, 0.78);
}

.page-about .partner-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin-bottom: clamp(22px, 3.4vw, 36px);
}

.page-about .partner-card {
  padding: 16px 18px 18px;
  border: 1.5px solid rgba(26, 19, 16, 0.18);
  background: rgba(255, 247, 232, 0.5);
}

.page-about .partner-card__value {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(32px, 5.4vw, 44px);
  line-height: 1;
  color: #c2510f;
}

.page-about .partner-card h3 {
  margin: 10px 0 6px;
  font-family: var(--font-display);
  font-size: 17px;
  letter-spacing: 0.06em;
  color: var(--brown);
}

.page-about .partner-card p {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: rgba(26, 19, 16, 0.76);
}

.page-about .cadence {
  border-top: 1.5px solid rgba(26, 19, 16, 0.18);
  padding-top: 18px;
}

.page-about .cadence__title {
  margin: 0 0 12px;
  font-family: var(--font-display);
  font-size: 18px;
  letter-spacing: 0.05em;
  color: var(--brown);
}

.page-about .cadence__list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .cadence__list li {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 4px;
  padding: 11px 0;
  border-bottom: 1px dashed rgba(26, 19, 16, 0.2);
}

.page-about .cadence__key {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.12em;
  color: #c2510f;
}

.page-about .cadence__val {
  font-size: 15px;
  line-height: 1.68;
  color: rgba(26, 19, 16, 0.85);
}

.page-about .cream-note {
  margin: 20px 0 0;
  font-size: 15px;
  line-height: 1.78;
  color: rgba(26, 19, 16, 0.82);
}

.page-about .cream-note a {
  color: #1d5fcb;
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .cream-note a:hover,
.page-about .cream-note a:focus-visible {
  color: #123f8a;
}

@media (min-width: 720px) {
  .page-about .partner-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .cadence__list li {
    grid-template-columns: 150px minmax(0, 1fr);
    gap: 16px;
    align-items: baseline;
  }
}

/* ===================== 结尾导航 ===================== */
.page-about .about-next {
  padding-top: var(--pa-rhythm);
  border-top: 1px solid var(--line);
}

.page-about .next-list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .next-item a {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 18px 18px 20px;
  background: rgba(6, 18, 14, 0.82);
  text-decoration: none;
  transition: background 0.2s var(--ease), transform 0.2s var(--ease);
}

.page-about .next-item a:hover,
.page-about .next-item a:focus-visible {
  background: rgba(255, 106, 31, 0.1);
  transform: translateY(-4px);
}

.page-about .next-item__k {
  font-family: var(--font-display);
  font-size: 18px;
  letter-spacing: 0.06em;
  color: var(--orange);
}

.page-about .next-item__v {
  font-size: 14px;
  line-height: 1.68;
  color: rgba(255, 247, 232, 0.74);
}

@media (min-width: 620px) {
  .page-about .next-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 1080px) {
  .page-about .next-list {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* ===================== 小屏收口 ===================== */
@media (max-width: 479px) {
  .page-about .hero-figures {
    grid-template-columns: minmax(0, 1fr);
  }

  .page-about .figframe--square {
    max-width: 100%;
  }

  .page-about .flow-svg {
    min-width: 460px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ver-card,
  .page-about .next-item a {
    transition: none;
  }
}