.page-about {
  --pa-rail: 212px;
  --pa-gap: clamp(24px, 3.4vw, 56px);
  padding-bottom: clamp(48px, 7vw, 110px);
  overflow-x: clip;
}

.page-about img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumb {
  padding-top: calc(var(--header-h) + 26px);
}

.page-about .about-crumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--mist);
}

.page-about .about-crumb__list .breadcrumb__link {
  color: var(--mist);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.page-about .about-crumb__list .breadcrumb__link:hover {
  color: var(--gold-glow);
  border-bottom-color: var(--gold);
}

.page-about .about-crumb__list .breadcrumb__current {
  color: var(--paper);
}

.page-about .about-crumb__list .breadcrumb__sep {
  color: var(--line);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: clamp(30px, 4.6vw, 62px) 0 clamp(26px, 3.6vw, 44px);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -180px;
  left: -12%;
  width: min(820px, 92vw);
  height: 560px;
  background: radial-gradient(ellipse at 32% 42%, var(--gold-a20), transparent 68%);
  pointer-events: none;
  z-index: 0;
}

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

.page-about .about-hero__inner {
  max-width: 880px;
}

.page-about .about-hero__title {
  margin: 14px 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(30px, 5vw, 58px);
  line-height: 1.12;
  letter-spacing: -0.02em;
  color: var(--paper);
  text-wrap: balance;
}

.page-about .about-hero__title::after {
  content: "";
  display: block;
  width: 88px;
  height: 2px;
  margin-top: 22px;
  background: linear-gradient(90deg, var(--gold), transparent);
}

.page-about .about-hero__lead {
  margin: 22px 0 0;
  max-width: 64ch;
  font-size: clamp(15px, 1.4vw, 17px);
  line-height: 1.85;
  color: var(--mist);
}

.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(28px, 3.8vw, 46px) 0 0;
  padding: 0;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-hero__stat {
  padding: 18px 18px 20px;
  background: var(--panel-2);
  transition: background-color 0.22s var(--ease);
}

.page-about .about-hero__stat:hover {
  background: var(--panel);
}

.page-about .about-hero__stat dt {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--mist);
}

.page-about .about-hero__stat dd {
  margin: 10px 0 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(24px, 3vw, 34px);
  line-height: 1;
  color: var(--paper);
  display: flex;
  align-items: baseline;
  gap: 5px;
}

.page-about .about-stat__num {
  font-size: inherit;
  letter-spacing: -0.01em;
  color: var(--gold-glow);
}

.page-about .about-stat__unit {
  font-family: var(--font-body);
  font-size: 13px;
  font-weight: 400;
  color: var(--mist);
}

/* ---------- 主体网格 ---------- */
.page-about .about-body {
  padding-top: clamp(36px, 5.4vw, 76px);
}

.page-about .about-body__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--pa-gap);
}

/* ---------- 左侧索引 ---------- */
.page-about .about-rail__label {
  margin: 0 0 12px;
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--gold);
}

.page-about .about-rail__list {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0 0 6px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
}

.page-about .about-rail__list::-webkit-scrollbar {
  display: none;
}

.page-about .about-rail__link {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 9px 14px;
  font-size: 13px;
  line-height: 1.4;
  color: var(--mist);
  text-decoration: none;
  white-space: nowrap;
  border: 1px solid var(--line);
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease), background-color 0.2s var(--ease);
}

.page-about .about-rail__link:hover {
  color: var(--gold-glow);
  border-color: var(--gold);
  background: var(--gold-a06);
}

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

/* ---------- 章节通用 ---------- */
.page-about .about-section {
  scroll-margin-top: calc(var(--header-h) + 22px);
  margin-top: clamp(38px, 5vw, 62px);
  padding-top: clamp(32px, 4.6vw, 54px);
  border-top: 1px solid var(--line);
  transition: border-color 0.24s var(--ease);
}

.page-about .about-flow > .about-section:first-child {
  margin-top: 0;
  padding-top: 0;
  border-top: 0;
}

.page-about .about-section:target {
  border-top-color: var(--gold);
}

.page-about .about-section__head {
  padding-left: 20px;
  border-left: 2px solid var(--gold);
}

.page-about .about-section__idx {
  display: block;
  font-size: 11.5px;
  letter-spacing: 0.18em;
  color: var(--gold);
}

.page-about .about-section__title {
  margin: 10px 0 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(21px, 2.5vw, 30px);
  line-height: 1.3;
  letter-spacing: -0.01em;
  color: var(--paper);
}

.page-about .about-section__sub {
  margin: 12px 0 0;
  max-width: 66ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--mist);
}

/* ---------- 01 团队分组 ---------- */
.page-about .about-roles {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin-top: 28px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-role {
  padding: 24px 20px 26px;
  background: var(--panel-2);
  transition: background-color 0.22s var(--ease);
}

.page-about .about-role:hover {
  background: var(--panel);
}

.page-about .about-role__meta {
  margin: 0;
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--cyan);
}

.page-about .about-role__name {
  margin: 12px 0 10px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 18px;
  color: var(--paper);
}

.page-about .about-role p:last-child {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--mist);
}

/* ---------- 02 验证流程 ---------- */
.page-about .about-figure-flow {
  margin: 30px 0 0;
}

.page-about .about-figure-flow .figure__frame,
.page-about .about-figure-cadence .figure__frame,
.page-about .about-matrix__fig .figure__frame {
  position: relative;
  border: 1px solid var(--line);
  background: var(--panel-2);
  overflow: hidden;
}

.page-about .about-figure-flow .figure__frame img,
.page-about .about-figure-cadence .figure__frame img,
.page-about .about-matrix__fig .figure__frame img {
  width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .about-figure-flow .figure__cap,
.page-about .about-figure-cadence .figure__cap,
.page-about .about-matrix__fig .figure__cap {
  margin-top: 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.6;
  letter-spacing: 0.03em;
  color: var(--mist);
}

.page-about .about-flowbar {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin-top: 26px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-flowbar__item {
  display: flex;
  flex-direction: column;
  background: var(--panel-2);
  transition: background-color 0.22s var(--ease);
}

.page-about .about-flowbar__item[data-open] {
  background: var(--panel);
}

.page-about .about-flowbar__trigger {
  display: flex;
  align-items: center;
  gap: 10px;
  width: 100%;
  padding: 17px 16px;
  margin: 0;
  background: none;
  border: 0;
  color: var(--paper);
  font: inherit;
  font-size: 14px;
  text-align: left;
  cursor: pointer;
  transition: color 0.2s var(--ease);
}

.page-about .about-flowbar__trigger:hover {
  color: var(--gold-glow);
}

.page-about .about-flowbar__trigger:focus-visible {
  outline: 1px solid var(--gold);
  outline-offset: -3px;
}

.page-about .about-flowbar__num {
  flex: 0 0 auto;
  font-size: 12px;
  color: var(--gold);
  transition: color 0.2s var(--ease);
}

.page-about .about-flowbar__item[data-open] .about-flowbar__num {
  color: var(--gold-glow);
}

.page-about .about-flowbar__name {
  flex: 1 1 auto;
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: 0.01em;
}

.page-about .about-flowbar__sign {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 15px;
  line-height: 1;
  color: var(--gold);
}

.page-about .about-flowbar__panel {
  padding: 0 16px 18px;
  font-size: 13.5px;
  line-height: 1.82;
  color: var(--mist);
}

.page-about .about-flowbar__panel p {
  margin: 0;
}

.page-about .about-flowbar__item:not([data-open]) .about-flowbar__panel {
  display: none;
}

/* ---------- 03 测试设备 ---------- */
.page-about .about-matrix {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(22px, 3vw, 34px);
  margin-top: 28px;
}

.page-about .about-filter {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 18px;
}

.page-about .about-filter__label {
  display: inline-flex;
  align-items: center;
  padding: 7px 13px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.05em;
  color: var(--mist);
  border: 1px solid var(--line);
  background: transparent;
  cursor: pointer;
  user-select: none;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease), background-color 0.2s var(--ease);
}

.page-about .about-filter__label:hover {
  color: var(--gold-glow);
  border-color: var(--gold-a40);
}

.page-about:has(#pf-android:checked) .about-filter__label[for="pf-android"],
.page-about:has(#pf-ios:checked) .about-filter__label[for="pf-ios"],
.page-about:has(#pf-win:checked) .about-filter__label[for="pf-win"],
.page-about:has(#pf-mac:checked) .about-filter__label[for="pf-mac"] {
  color: var(--gold-glow);
  border-color: var(--gold);
  background: var(--gold-a10);
}

.page-about .about-matrix__tablewrap {
  overflow-x: auto;
}

.page-about .about-devtable {
  width: 100%;
  min-width: 440px;
  border-collapse: collapse;
  font-size: 13.5px;
}

.page-about .about-devtable th,
.page-about .about-devtable td {
  padding: 13px 14px;
  text-align: left;
  vertical-align: middle;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-devtable thead th {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 400;
  letter-spacing: 0.1em;
  color: var(--mist);
  border-bottom-color: var(--gold-a40);
}

.page-about .about-devtable tbody th {
  font-weight: 600;
  color: var(--paper);
  white-space: nowrap;
}

.page-about .about-devtable tbody td {
  color: var(--mist);
}

.page-about .about-devtable tbody tr {
  transition: background-color 0.2s var(--ease);
}

.page-about .about-devtable tbody tr:hover {
  background: var(--gold-a06);
}

.page-about .about-dot {
  display: inline-block;
  width: 7px;
  height: 7px;
  margin-right: 8px;
  border-radius: 50%;
  vertical-align: middle;
  background: currentColor;
}

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

.page-about .about-dot--ios {
  color: var(--gold);
}

.page-about .about-dot--win {
  color: var(--magenta);
}

.page-about .about-dot--mac {
  color: var(--paper);
}

.page-about:has(#pf-android:checked) .dev-row:not(.dev-row--android),
.page-about:has(#pf-ios:checked) .dev-row:not(.dev-row--ios),
.page-about:has(#pf-win:checked) .dev-row:not(.dev-row--win),
.page-about:has(#pf-mac:checked) .dev-row:not(.dev-row--mac) {
  display: none;
}

/* ---------- 04 版本节奏 ---------- */
.page-about .about-cadence {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 3vw, 32px);
  margin-top: 30px;
}

.page-about .about-ctrack {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border: 1px solid var(--line);
  border-top-color: var(--gold-a40);
}

.page-about .about-ctrack__item {
  position: relative;
  padding: 26px 20px 26px;
  background: var(--panel-2);
  transition: background-color 0.22s var(--ease);
}

.page-about .about-ctrack__item:hover {
  background: var(--panel);
}

.page-about .about-ctrack__item::before {
  content: "";
  position: absolute;
  top: -5px;
  left: 20px;
  width: 8px;
  height: 8px;
  background: var(--gold);
  transform: rotate(45deg);
}

.page-about .about-ctrack__num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 19px;
  letter-spacing: 0.01em;
  color: var(--cyan);
}

.page-about .about-ctrack__title {
  margin: 10px 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 16px;
  color: var(--paper);
}

.page-about .about-ctrack__item p:last-child {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--mist);
}

.page-about .about-ringbox {
  display: flex;
  align-items: center;
  gap: 18px;
  padding: 20px;
  border: 1px solid var(--line);
  background: linear-gradient(160deg, rgba(22, 32, 60, 0.6), transparent 72%);
}

.page-about .about-ring {
  flex: 0 0 auto;
  width: 88px;
  height: 88px;
}

.page-about .about-ring .ring-track {
  fill: none;
  stroke: var(--line);
  stroke-width: 1;
}

.page-about .about-ring .ring-arc {
  fill: none;
  stroke: var(--gold);
  stroke-width: 2;
  opacity: 0.85;
}

.page-about .about-ring .ring-arc--b {
  stroke: var(--cyan);
  opacity: 0.65;
}

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

.page-about .about-figure-cadence {
  margin: 30px 0 0;
}

/* ---------- 05 内容分类 ---------- */
.page-about .about-cats {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: 28px 0 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-cat {
  padding: 22px 20px 24px;
  background: var(--panel-2);
  transition: background-color 0.22s var(--ease);
}

.page-about .about-cat:hover {
  background: var(--panel);
}

.page-about .about-cat__code {
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--cyan);
}

.page-about .about-cat__name {
  margin: 10px 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 16px;
  color: var(--paper);
}

.page-about .about-cat p:last-child {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--mist);
}

.page-about .about-cats__note {
  margin: 22px 0 0;
  padding-left: 16px;
  border-left: 2px solid var(--gold);
  font-size: 14px;
  line-height: 1.85;
  color: var(--mist);
}

/* ---------- 06 反馈 ---------- */
.page-about .about-feedback {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin-top: 28px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-feedback__text {
  padding: 26px 22px;
  background: var(--panel-2);
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--mist);
}

.page-about .about-feedback__text p {
  margin: 0;
}

.page-about .about-feedback__steps {
  margin: 18px 0 0;
  padding: 0 0 0 20px;
  list-style: none;
  counter-reset: fbstep;
}

.page-about .about-feedback__steps li {
  position: relative;
  counter-increment: fbstep;
  padding: 8px 0 8px 26px;
  line-height: 1.8;
  border-bottom: 1px solid var(--line-soft);
}

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

.page-about .about-feedback__steps li::before {
  content: counter(fbstep, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--cyan);
}

.page-about .about-feedback__card {
  padding: 26px 22px;
  background: linear-gradient(150deg, var(--gold-a10), transparent 62%), var(--panel-2);
}

.page-about .about-feedback__key {
  margin: 0;
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--gold);
}

.page-about .about-feedback__val {
  margin: 12px 0 0;
  font-family: var(--font-mono);
  font-size: 15px;
  line-height: 1.5;
  color: var(--paper);
  overflow-wrap: anywhere;
}

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

/* ---------- 收尾入口 ---------- */
.page-about .about-next {
  margin-top: clamp(46px, 6.6vw, 86px);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(22, 32, 60, 0.55), transparent);
}

.page-about .about-next__inner {
  padding: clamp(30px, 4vw, 48px) 0;
}

.page-about .about-next__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(18px, 2.1vw, 24px);
  color: var(--paper);
}

.page-about .about-next__list {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-next__link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 18px;
  background: var(--panel-2);
  color: var(--paper);
  font-size: 14px;
  line-height: 1.5;
  text-decoration: none;
  transition: background-color 0.22s var(--ease), color 0.22s var(--ease);
}

.page-about .about-next__link::after {
  content: "→";
  flex: 0 0 auto;
  font-family: var(--font-mono);
  color: var(--gold);
  transition: transform 0.22s var(--ease);
}

.page-about .about-next__link:hover {
  background: var(--panel);
  color: var(--gold-glow);
}

.page-about .about-next__link:hover::after {
  transform: translateX(4px);
}

/* ---------- 平板 ---------- */
@media (min-width: 720px) {
  .page-about .about-hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

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

@media (min-width: 860px) {
  .page-about .about-roles {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-cadence {
    grid-template-columns: minmax(0, 1fr) 220px;
    align-items: start;
  }

  .page-about .about-ringbox {
    flex-direction: column;
    align-items: flex-start;
    gap: 14px;
  }

  .page-about .about-feedback {
    grid-template-columns: minmax(0, 1.5fr) minmax(0, 1fr);
  }
}

@media (min-width: 960px) {
  .page-about .about-flowbar {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }

  .page-about .about-matrix {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr);
    align-items: start;
  }
}

/* ---------- 桌面：常驻左栏 ---------- */
@media (min-width: 1040px) {
  .page-about .about-body__grid {
    grid-template-columns: var(--pa-rail) minmax(0, 1fr);
  }

  .page-about .about-rail {
    position: sticky;
    top: calc(var(--header-h) + 30px);
    align-self: start;
  }

  .page-about .about-rail__list {
    flex-direction: column;
    gap: 0;
    padding: 0;
    overflow: visible;
    border-left: 1px solid var(--line);
  }

  .page-about .about-rail__link {
    white-space: normal;
    margin-left: -1px;
    padding: 10px 14px;
    border: 0;
    border-left: 1px solid transparent;
  }

  .page-about .about-rail__link:hover {
    border-left-color: var(--gold);
    background: var(--gold-a06);
  }
}

@media (min-width: 1140px) {
  .page-about .about-cats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about * {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }
}