.page-about {
  --about-idx-w: 208px;
  --about-gap: 44px;
  --about-paper-line: rgba(22, 35, 61, 0.16);
  --about-grid-line: rgba(30, 58, 107, 0.55);
  position: relative;
  background-color: var(--ink-deep);
  background-image:
    linear-gradient(to right, var(--about-grid-line) 1px, transparent 1px),
    linear-gradient(to bottom, var(--about-grid-line) 1px, transparent 1px);
  background-size: 72px 72px;
  color: var(--text);
  overflow-x: clip;
}

.page-about .about-hero {
  position: relative;
  padding: clamp(20px, 4vw, 40px) 0 clamp(40px, 6vw, 76px);
  border-bottom: 1px solid var(--line);
  background:
    radial-gradient(circle at 82% 18%, rgba(61, 224, 208, 0.14), transparent 58%),
    radial-gradient(circle at 12% 90%, rgba(245, 197, 66, 0.1), transparent 60%);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  background: linear-gradient(to right, var(--gold) 0 72px, transparent 72px);
}

.page-about .hero-grid {
  display: grid;
  gap: 28px;
  margin-top: 26px;
}

.page-about .hero-title {
  font-family: var(--font-sans);
  font-size: clamp(30px, 7vw, 62px);
  font-weight: 300;
  line-height: 1.12;
  letter-spacing: -0.02em;
  margin: 12px 0 18px;
}

.page-about .hero-title .hl {
  display: inline;
  font-weight: 700;
  color: var(--gold);
}

.page-about .hero-lead {
  margin: 0;
  max-width: 56ch;
  font-size: 15px;
  line-height: 1.85;
  color: var(--muted);
}

.page-about .hero-facts {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 20px 34px;
  margin: 26px 0 0;
  padding: 22px 0 0;
  border-top: 1px solid var(--line);
}

.page-about .fact {
  display: flex;
  flex-direction: column;
  gap: 4px;
  min-width: 96px;
}

.page-about .fact__num {
  font-family: var(--font-mono);
  font-size: 26px;
  font-weight: 500;
  line-height: 1;
  color: var(--cyan);
  letter-spacing: -0.02em;
}

.page-about .fact__txt {
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--muted);
}

.page-about .hero-media {
  position: relative;
  margin: 0;
  padding: 8px;
  border: 1px solid var(--line);
  background: var(--ink-void);
}

.page-about .hero-media::before {
  content: "";
  position: absolute;
  top: -1px;
  left: -1px;
  width: 56px;
  height: 3px;
  background: var(--gold);
}

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

.page-about .hero-media figcaption {
  margin-top: 8px;
  font-size: 11px;
  line-height: 1.6;
  letter-spacing: 0.04em;
  color: var(--muted);
}

/* 主体两栏 */
.page-about .about-body {
  padding: clamp(28px, 4vw, 56px) 0 clamp(40px, 6vw, 88px);
}

.page-about .about-layout {
  display: grid;
  gap: 28px;
}

/* 章节索引 */
.page-about .about-index {
  position: sticky;
  top: 0;
  z-index: 4;
  background: var(--ink-void);
  border-bottom: 1px solid var(--line);
  padding: 10px 0 8px;
  margin: 0 calc(var(--edge) * -1);
}

.page-about .about-index__label {
  display: none;
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--muted);
}

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

.page-about .about-index__link {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 6px 10px;
  white-space: nowrap;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--muted);
  text-decoration: none;
  border: 1px solid var(--line);
  background: var(--ink-void);
  transition: color 0.18s ease, border-color 0.18s ease;
}

.page-about .about-index__no {
  font-family: var(--font-mono);
  font-size: 10px;
  color: var(--cyan);
}

.page-about .about-index__link:hover,
.page-about .about-index__link:focus-visible {
  color: var(--gold);
  border-color: var(--gold);
  outline: none;
}

/* 章节通用 */
.page-about .about-sec {
  padding: clamp(30px, 4.4vw, 56px) 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-sec:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}

.page-about .section-title {
  font-family: var(--font-sans);
  font-size: clamp(21px, 3.2vw, 32px);
  font-weight: 700;
  line-height: 1.28;
  letter-spacing: -0.01em;
  margin: 8px 0 18px;
}

.page-about .prose {
  max-width: 64ch;
  margin: 0 0 16px;
  font-size: 15px;
  line-height: 1.85;
}

.page-about .prose strong {
  color: var(--gold);
  font-weight: 700;
}

.page-about .kicker {
  color: var(--cyan);
}

.page-about .kicker--ink {
  color: #4A5F86;
}

.page-about .reveal {
  opacity: 0;
  transform: translateY(8px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

.page-about .reveal.is-visible {
  opacity: 1;
  transform: none;
}

/* 起步小节 */
.page-about .origin-strip {
  display: grid;
  gap: 1px;
  margin-top: 24px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .origin-strip__item {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 16px 18px;
  background: var(--ink-deep);
}

.page-about .origin-strip__k {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--cyan);
}

.page-about .origin-strip__v {
  font-size: 14px;
  line-height: 1.6;
  color: var(--text);
}

/* 时间线 */
.page-about .tl {
  list-style: none;
  margin: 26px 0 0;
  padding: 0 0 0 22px;
  position: relative;
}

.page-about .tl::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: var(--line);
}

.page-about .tl__item {
  position: relative;
  padding: 0 0 26px;
  outline: none;
}

.page-about .tl__item:last-child {
  padding-bottom: 0;
}

.page-about .tl__item::before {
  content: "";
  position: absolute;
  left: -21px;
  top: 8px;
  width: 7px;
  height: 7px;
  background: var(--ink-deep);
  border: 1px solid var(--line);
  transform: rotate(45deg);
  transition: background 0.2s ease, border-color 0.2s ease;
}

.page-about .tl__item:hover::before,
.page-about .tl__item:focus-visible::before {
  background: var(--cyan);
  border-color: var(--cyan);
}

.page-about .tl__item--now::before {
  background: var(--gold);
  border-color: var(--gold);
}

.page-about .tl__year {
  display: block;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--muted);
  margin-bottom: 4px;
}

.page-about .tl__item--now .tl__year {
  color: var(--gold);
}

.page-about .tl__title {
  margin: 0 0 4px;
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 0.01em;
}

.page-about .tl__desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--muted);
}

.page-about .tl__more {
  display: grid;
  grid-template-rows: 1fr;
  overflow: hidden;
}

.page-about .tl__more > p {
  margin: 6px 0 0;
  overflow: hidden;
  font-size: 13px;
  line-height: 1.75;
  color: #7E93B8;
}

/* 浅色阅读面板 */
.page-about .about-sec--paper {
  border-bottom: 0;
  padding-left: 0;
  padding-right: 0;
}

.page-about .reading-panel {
  position: relative;
  background: var(--paper);
  color: var(--paper-ink);
  border: 1px solid var(--line);
  padding: clamp(20px, 4vw, 42px);
}

.page-about .reading-panel::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 6px;
  background-image: repeating-linear-gradient(to right, var(--line) 0 1px, transparent 1px 12px);
  opacity: 0.6;
}

.page-about .reading-panel .prose {
  color: #2B3A57;
}

.page-about .reading-panel .prose strong {
  color: #0E2A55;
}

.page-about .reading-panel .section-title {
  color: var(--paper-ink);
}

.page-about .paper-figure {
  margin: 20px 0 22px;
  border: 1px solid var(--about-paper-line);
  background: #E4EAF6;
}

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

.page-about .paper-figure figcaption {
  padding: 8px 10px;
  font-size: 12px;
  line-height: 1.6;
  color: #4A5F86;
  border-top: 1px solid var(--about-paper-line);
}

/* 字号切换 */
.page-about .font-switch {
  display: flex;
  gap: 0;
  margin: 0 0 18px;
  border: 1px solid var(--about-paper-line);
  width: max-content;
}

.page-about .fs-input {
  position: absolute;
  opacity: 0;
  width: 1px;
  height: 1px;
  pointer-events: none;
}

.page-about .fs-label {
  padding: 6px 14px;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: #4A5F86;
  cursor: pointer;
  background: transparent;
  transition: background 0.18s ease, color 0.18s ease;
}

.page-about .fs-label + .fs-input + .fs-label {
  border-left: 1px solid var(--about-paper-line);
}

.page-about .fs-input:checked + .fs-label {
  background: #0E2A55;
  color: var(--paper);
}

.page-about .fs-input:focus-visible + .fs-label {
  outline: 2px solid var(--cyan);
  outline-offset: -2px;
}

.page-about .data-body {
  font-size: 15px;
  transition: font-size 0.2s ease;
}

.page-about .data-panel:has(#about-fs-large:checked) .data-body {
  font-size: 17px;
}

/* 三段流转 */
.page-about .flow {
  list-style: none;
  display: grid;
  gap: 18px;
  margin: 24px 0 22px;
  padding: 0;
}

.page-about .flow__step {
  padding: 16px 16px 18px;
  background: rgba(11, 27, 58, 0.035);
  border: 1px solid var(--about-paper-line);
  border-left: 3px solid var(--cyan);
}

.page-about .flow__step:nth-child(2) {
  border-left-color: var(--gold);
}

.page-about .flow__step:nth-child(3) {
  border-left-color: #5B7BB0;
}

.page-about .flow__no {
  display: block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: #5A6E93;
  margin-bottom: 6px;
}

.page-about .flow__title {
  margin: 0 0 8px;
  font-size: 16px;
  font-weight: 700;
  color: var(--paper-ink);
}

.page-about .flow__step p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: #2B3A57;
}

.page-about .flow__step p strong {
  color: #0E2A55;
}

.page-about .data-note {
  margin-bottom: 0;
  padding-top: 16px;
  border-top: 1px dashed var(--about-paper-line);
}

/* 团队 */
.page-about .team-filter {
  margin: 4px 0 18px;
}

.page-about .roles {
  list-style: none;
  display: grid;
  gap: 14px;
  margin: 0 0 26px;
  padding: 0;
}

.page-about .role {
  padding: 14px 16px 16px;
  background: #FFFFFF;
  border: 1px solid var(--about-paper-line);
}

.page-about .role[hidden] {
  display: none;
}

.page-about .role__head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 10px;
}

.page-about .role__name {
  font-size: 15px;
  font-weight: 700;
  color: var(--paper-ink);
}

.page-about .role__num {
  font-family: var(--font-mono);
  font-size: 14px;
  color: #0E2A55;
}

.page-about .role__bar {
  height: 6px;
  background: rgba(11, 27, 58, 0.09);
  overflow: hidden;
}

.page-about .role__bar span {
  display: block;
  height: 100%;
  transition: width 0.4s ease;
}

.page-about .role--data .role__bar span {
  width: 36%;
  background: #D8A81C;
}

.page-about .role--content .role__bar span {
  width: 16%;
  background: #14A99B;
}

.page-about .role--product .role__bar span {
  width: 48%;
  background: #5B7BB0;
}

.page-about .role__desc {
  margin: 12px 0 0;
  font-size: 14px;
  line-height: 1.8;
  color: #2B3A57;
}

.page-about .team-figure {
  margin-bottom: 0;
}

/* 合作生态 */
.page-about .partner-grid {
  display: grid;
  gap: 16px;
  margin-top: 24px;
}

.page-about .partner-card {
  padding: 20px 20px 22px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-top: 3px solid var(--cyan);
}

.page-about .partner-card:nth-child(2) {
  border-top-color: var(--gold);
}

.page-about .partner-card--wide {
  border-top-color: var(--magenta);
}

.page-about .partner-card__num {
  margin: 0 0 4px;
  font-family: var(--font-mono);
  font-size: 40px;
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--cyan);
}

.page-about .partner-card:nth-child(2) .partner-card__num {
  color: var(--gold);
}

.page-about .partner-card__title {
  margin: 0 0 10px;
  font-size: 15px;
  font-weight: 700;
  color: var(--text);
}

.page-about .partner-card p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .partner-card p strong {
  color: var(--text);
}

/* 迭代节奏 */
.page-about .cadence-grid {
  display: grid;
  gap: 1px;
  margin-top: 24px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .cadence-item {
  padding: 18px 18px 20px;
  background: var(--ink-deep);
}

.page-about .cadence-item__tag {
  display: inline-block;
  margin-bottom: 10px;
  padding: 3px 9px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--ink-void);
  background: var(--gold);
}

.page-about .cadence-item:nth-child(2n) .cadence-item__tag {
  background: var(--cyan);
}

.page-about .cadence-item__title {
  margin: 0 0 8px;
  font-size: 16px;
  font-weight: 700;
  color: var(--text);
}

.page-about .cadence-item p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
}

/* 下一步 */
.page-about .about-sec--next {
  border-bottom: 0;
  padding-bottom: 0;
}

.page-about .next-grid {
  display: grid;
  gap: 12px;
  margin-top: 22px;
}

.page-about .next-link {
  position: relative;
  display: grid;
  grid-template-columns: auto 1fr auto;
  grid-template-areas:
    "no title arrow"
    "no desc arrow";
  align-items: center;
  gap: 2px 14px;
  padding: 18px 18px;
  background: var(--ink-void);
  border: 1px solid var(--line);
  text-decoration: none;
  transition: border-color 0.2s ease, background 0.2s ease;
}

.page-about .next-link::after {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 0;
  height: 2px;
  background: var(--cyan);
  transition: width 0.28s ease;
}

.page-about .next-link:hover,
.page-about .next-link:focus-visible {
  border-color: var(--cyan);
  background: var(--panel);
  outline: none;
}

.page-about .next-link:hover::after,
.page-about .next-link:focus-visible::after {
  width: 100%;
}

.page-about .next-link__no {
  grid-area: no;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--cyan);
  align-self: start;
  padding-top: 2px;
}

.page-about .next-link__title {
  grid-area: title;
  font-size: 15px;
  font-weight: 700;
  color: var(--text);
}

.page-about .next-link__desc {
  grid-area: desc;
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
}

.page-about .next-link__arrow {
  grid-area: arrow;
  font-size: 18px;
  color: var(--gold);
  transition: transform 0.2s ease;
}

.page-about .next-link:hover .next-link__arrow,
.page-about .next-link:focus-visible .next-link__arrow {
  transform: translateX(4px);
}

@media (min-width: 720px) {
  .page-about .hero-facts {
    gap: 0;
  }

  .page-about .fact {
    padding-right: 34px;
    margin-right: 34px;
    border-right: 1px solid var(--line);
  }

  .page-about .fact:last-child {
    border-right: 0;
    margin-right: 0;
    padding-right: 0;
  }

  .page-about .origin-strip {
    grid-template-columns: repeat(3, 1fr);
  }

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

  .page-about .partner-card--wide {
    grid-column: 1 / -1;
  }

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

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

@media (min-width: 900px) {
  .page-about .hero-grid {
    grid-template-columns: minmax(0, 1fr) 340px;
    gap: 52px;
    align-items: end;
    margin-top: 34px;
  }

  .page-about .hero-media {
    transform: translateY(18px);
  }

  .page-about .tl {
    display: grid;
    grid-template-columns: repeat(5, minmax(0, 1fr));
    gap: 22px;
    padding: 0;
  }

  .page-about .tl::before {
    display: none;
  }

  .page-about .tl__item {
    padding: 24px 0 0;
    border-top: 1px solid var(--line);
  }

  .page-about .tl__item::before {
    left: 0;
    top: -5px;
  }

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

  .page-about .tl__more {
    grid-template-rows: 0fr;
    transition: grid-template-rows 0.28s ease;
  }

  .page-about .tl__item:hover .tl__more,
  .page-about .tl__item:focus-visible .tl__more {
    grid-template-rows: 1fr;
  }

  .page-about .flow {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    align-items: start;
    gap: 20px;
  }

  .page-about .flow__step:nth-child(2) {
    margin-top: 26px;
  }

  .page-about .flow__step:nth-child(3) {
    margin-top: 52px;
  }

  .page-about .roles {
    grid-template-columns: 1fr;
  }
}

@media (min-width: 1040px) {
  .page-about .about-layout {
    grid-template-columns: var(--about-idx-w) minmax(0, 1fr);
    gap: var(--about-gap);
    align-items: start;
  }

  .page-about .about-index {
    position: sticky;
    top: calc(var(--top-h) + 20px);
    z-index: 2;
    margin: 0;
    padding: 0 0 0 16px;
    background: transparent;
    border-bottom: 0;
    border-left: 1px solid var(--line);
  }

  .page-about .about-index__label {
    display: block;
  }

  .page-about .about-index__list {
    flex-direction: column;
    gap: 0;
    padding: 0;
    overflow: visible;
  }

  .page-about .about-index__link {
    position: relative;
    padding: 9px 0 9px 14px;
    border: 0;
    background: transparent;
    font-size: 13px;
  }

  .page-about .about-index__link::before {
    content: "";
    position: absolute;
    left: -17px;
    top: 50%;
    width: 9px;
    height: 1px;
    background: var(--line);
    transition: width 0.2s ease, background 0.2s ease;
  }

  .page-about .about-index__link:hover::before,
  .page-about .about-index__link:focus-visible::before {
    width: 20px;
    background: var(--gold);
  }

  .page-about .about-sec {
    padding: clamp(36px, 3.4vw, 58px) 0;
  }

  .page-about .team-panel .roles {
    grid-template-columns: 1fr;
  }

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

  .page-about .next-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
  }

  .page-about .next-grid .next-link:nth-child(2n) {
    transform: translateY(18px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .page-about .tl__more,
  .page-about .role__bar span,
  .page-about .next-link,
  .page-about .next-link__arrow {
    transition: none;
  }
}