.page-about {
  --about-index-w: 172px;
  --about-panel-bg: var(--panel);
}

/* 首屏 */
.page-about .about-masthead {
  display: grid;
  gap: clamp(18px, 3vw, 30px);
  padding-block: clamp(18px, 3vw, 38px) clamp(20px, 3vw, 36px);
  border-bottom: 1px solid var(--line);
}

.page-about .about-masthead__mark {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--paper);
}

.page-about .about-masthead__mark::before {
  content: "";
  width: 26px;
  height: 1px;
  background: var(--orange);
}

.page-about .about-masthead__title {
  margin: 0 0 16px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(28px, 6vw, 58px);
  line-height: 1.06;
  letter-spacing: -0.012em;
  color: var(--mist);
  text-wrap: balance;
}

.page-about .about-masthead__lede {
  margin: 0 0 16px;
  max-width: 56ch;
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.85;
  color: var(--silver);
}

.page-about .about-masthead__note {
  margin: 0;
  max-width: 52ch;
  font-size: 12px;
  line-height: 1.75;
  color: var(--concrete);
  border-left: 2px solid var(--orange-deep);
  padding-left: 12px;
}

.page-about .about-masthead__figure {
  margin: 0;
}

.page-about .figure__media {
  overflow: hidden;
  border: 1px solid var(--line-mid);
  background: var(--ink-deep);
}

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

.page-about .about-masthead__cap,
.page-about .about-figure__cap {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  line-height: 1.7;
  letter-spacing: 0.02em;
  color: var(--concrete);
}

@media (min-width: 880px) {
  .page-about .about-masthead {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: start;
    column-gap: clamp(28px, 4vw, 60px);
  }
}

/* 主体：索引 + 面板 */
.page-about .about-body {
  display: grid;
  gap: clamp(22px, 3vw, 40px);
  margin-top: clamp(26px, 4vw, 56px);
}

.page-about .about-index {
  border-top: 1px solid var(--line-mid);
  padding-top: 12px;
}

.page-about .about-index__head {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--concrete);
}

.page-about .about-index__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 4px 16px;
}

.page-about .about-index__link {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 6px 0;
  font-size: 13px;
  color: var(--silver);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-index__link:hover,
.page-about .about-index__link:focus-visible {
  color: var(--orange);
  border-bottom-color: var(--orange-deep);
}

.page-about .about-index__num {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--concrete);
}

.page-about .about-index__link:hover .about-index__num,
.page-about .about-index__link:focus-visible .about-index__num {
  color: var(--orange);
}

@media (min-width: 1024px) {
  .page-about .about-body {
    grid-template-columns: var(--about-index-w) minmax(0, 1fr);
    gap: clamp(28px, 4vw, 64px);
    align-items: start;
  }
  .page-about .about-index {
    position: sticky;
    top: clamp(16px, 3vw, 40px);
  }
  .page-about .about-index__list {
    flex-direction: column;
    flex-wrap: nowrap;
    gap: 0;
  }
  .page-about .about-index__link {
    width: 100%;
    padding: 8px 0;
    border-bottom-color: var(--line);
  }
  .page-about .about-index__link:hover,
  .page-about .about-index__link:focus-visible {
    border-bottom-color: var(--orange);
  }
}

/* 面板 */
.page-about .about-panel {
  background: var(--about-panel-bg);
  border: 1px solid var(--line);
  padding: clamp(18px, 3vw, 36px);
  margin-bottom: clamp(16px, 2.4vw, 26px);
  scroll-margin-top: 88px;
}

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

@media (min-width: 1024px) {
  .page-about .about-content > .about-panel:nth-child(even) {
    margin-left: clamp(14px, 2vw, 30px);
  }
}

.page-about .about-panel--trust {
  border-color: rgba(255, 106, 26, 0.34);
}

.page-about .about-panel__head {
  display: flex;
  align-items: center;
  gap: 12px;
  padding-bottom: 14px;
  margin-bottom: 18px;
  border-bottom: 1px solid var(--line);
}

.page-about .about-panel__num {
  flex: none;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  padding: 4px 7px;
  background: var(--paper);
  color: var(--ink);
}

.page-about .about-panel__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(19px, 2.6vw, 27px);
  line-height: 1.22;
  letter-spacing: -0.004em;
  color: var(--mist);
}

.page-about .about-panel p {
  margin: 0 0 14px;
  max-width: 68ch;
  font-size: 15px;
  line-height: 1.85;
  color: var(--silver);
}

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

.page-about .about-panel a:not(.btn) {
  color: var(--paper);
  text-decoration: none;
  border-bottom: 1px solid var(--orange-deep);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-panel a:not(.btn):hover,
.page-about .about-panel a:not(.btn):focus-visible {
  color: var(--orange);
  border-bottom-color: var(--orange);
}

/* 版本时间轴 */
.page-about .about-timeline {
  list-style: none;
  margin: 20px 0 0;
  padding: 0;
  position: relative;
}

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

.page-about .about-step {
  position: relative;
  padding: 0 0 clamp(20px, 3vw, 30px) 34px;
}

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

.page-about .about-step::before {
  content: "";
  position: absolute;
  left: 0;
  top: 25px;
  width: 11px;
  height: 11px;
  background: var(--ink);
  border: 1px solid var(--paper);
  transition: background var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-step::after {
  content: "";
  position: absolute;
  left: 11px;
  top: 30px;
  width: 0;
  height: 1px;
  background: var(--orange);
  transition: width 180ms var(--ease);
}

.page-about .about-step:hover::before,
.page-about .about-step:focus-within::before {
  background: var(--orange);
  border-color: var(--orange);
}

.page-about .about-step:hover::after,
.page-about .about-step:focus-within::after {
  width: 14px;
}

.page-about .about-step__ver {
  display: inline-block;
  margin-bottom: 8px;
  padding: 2px 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--paper);
  border: 1px solid var(--line-mid);
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

.page-about .about-step:hover .about-step__ver,
.page-about .about-step:focus-within .about-step__ver {
  color: var(--orange);
  border-color: var(--orange-deep);
}

.page-about .about-step__title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(16px, 1.9vw, 19px);
  line-height: 1.35;
  color: var(--mist);
}

.page-about .about-step__meta {
  font-family: var(--font-mono);
  font-size: 11px;
  line-height: 1.7;
  color: var(--concrete);
  margin-bottom: 0;
}

/* 章节配图 */
.page-about .about-figure {
  margin: clamp(18px, 3vw, 28px) 0 0;
}

.page-about .about-figure--wide {
  max-width: 760px;
}

.page-about .about-figure--square {
  max-width: 440px;
}

/* 团队档案卡 */
.page-about .about-team {
  display: grid;
  gap: 12px;
  margin-top: 20px;
}

.page-about .about-card {
  background: var(--panel-soft);
  border: 1px solid var(--line-mid);
  transition: border-color var(--dur) var(--ease);
}

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

.page-about .about-card__sum {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 14px 16px;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 16px;
  letter-spacing: 0.005em;
  color: var(--mist);
}

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

.page-about .about-card__sum::after {
  content: "+";
  margin-left: 10px;
  font-family: var(--font-mono);
  font-weight: 400;
  font-size: 15px;
  color: var(--orange);
}

.page-about .about-card[open] .about-card__sum::after {
  content: "–";
}

.page-about .about-card__sum:hover {
  color: var(--orange);
}

.page-about .about-card__idx {
  flex: none;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 400;
  line-height: 1;
  padding: 4px 6px;
  background: var(--paper);
  color: var(--ink);
}

.page-about .about-card__name {
  min-width: 0;
}

.page-about .about-card__count {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 400;
  color: var(--concrete);
}

.page-about .about-card__body {
  padding: 0 16px 16px;
  border-top: 1px solid var(--line);
}

.page-about .about-card__body p {
  margin: 12px 0 0;
  max-width: 48ch;
  font-size: 14px;
  line-height: 1.8;
  color: var(--silver);
}

@media (min-width: 760px) {
  .page-about .about-team {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: clamp(14px, 2vw, 24px);
    row-gap: clamp(14px, 2vw, 22px);
  }
  .page-about .about-card:nth-child(even) {
    margin-top: clamp(14px, 2.6vw, 30px);
  }
}

/* 三层归档 */
.page-about .about-layers {
  list-style: none;
  margin: 20px 0 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .about-layer {
  padding: 0 0 0 14px;
  border-left: 2px solid rgba(255, 106, 26, 0.55);
}

.page-about .about-layer__step {
  display: block;
  margin-bottom: 6px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--concrete);
}

.page-about .about-layer__name {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 17px;
  line-height: 1.3;
  color: var(--paper);
}

.page-about .about-layer p {
  margin: 0;
  max-width: 40ch;
  font-size: 14px;
  line-height: 1.8;
  color: var(--silver);
}

@media (min-width: 800px) {
  .page-about .about-layers {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 0;
  }
  .page-about .about-layer {
    padding: 16px 20px 0;
    border-left: 0;
    border-top: 2px solid var(--orange-deep);
  }
  .page-about .about-layer + .about-layer {
    border-left: 1px solid var(--line);
  }
  .page-about .about-layer:first-child {
    padding-left: 0;
  }
}

.page-about .about-review {
  margin-top: clamp(18px, 3vw, 26px);
  padding: clamp(14px, 2vw, 20px);
  background: rgba(230, 211, 163, 0.07);
  border-left: 1px solid var(--paper);
}

.page-about .about-review p {
  margin: 0;
  font-size: 14px;
  line-height: 1.85;
  color: var(--silver);
}

/* 服务范围 */
.page-about .about-reach {
  display: grid;
  gap: 14px;
  margin-top: 20px;
}

.page-about .about-reach__col {
  padding: clamp(14px, 2vw, 20px);
  background: var(--ink-deep);
  border: 1px solid var(--line);
}

.page-about .about-reach__col--paper {
  background: rgba(230, 211, 163, 0.08);
  border-color: rgba(230, 211, 163, 0.28);
}

.page-about .about-reach__name {
  margin: 0 0 12px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 16px;
  line-height: 1.3;
  color: var(--paper);
}

.page-about .about-reach__list {
  list-style: none;
  margin: 0 0 12px;
  padding: 0;
}

.page-about .about-reach__list li {
  position: relative;
  padding: 5px 0 5px 14px;
  font-size: 14px;
  line-height: 1.75;
  color: var(--silver);
  border-bottom: 1px solid var(--line);
}

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

.page-about .about-reach__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 14px;
  width: 5px;
  height: 5px;
  background: var(--blue);
}

.page-about .about-reach__col--paper .about-reach__list li::before {
  background: var(--orange);
}

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

@media (min-width: 760px) {
  .page-about .about-reach {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: 16px;
  }
}

/* 品牌认证与服务中心 */
.page-about .about-trust {
  display: grid;
  gap: 18px;
  margin-top: 4px;
}

.page-about .about-trust__name {
  margin: 0 0 10px;
  padding-bottom: 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 15px;
  letter-spacing: 0.01em;
  color: var(--paper);
  border-bottom: 1px solid var(--line-mid);
}

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

.page-about .about-trust__list li {
  padding: 7px 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--silver);
  border-bottom: 1px solid var(--line);
}

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

.page-about .about-trust__k {
  display: inline-block;
  margin-right: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--orange);
}

.page-about .about-trust__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: clamp(18px, 3vw, 26px);
  padding-top: clamp(16px, 2.5vw, 22px);
  border-top: 1px solid var(--line);
}

@media (min-width: 760px) {
  .page-about .about-trust {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: clamp(20px, 3vw, 34px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-step::before,
  .page-about .about-step::after,
  .page-about .about-step__ver,
  .page-about .about-card,
  .page-about .about-index__link,
  .page-about .about-panel a:not(.btn) {
    transition: none;
  }
}