/* ============================================================
   品牌档案 /about/
   ============================================================ */

.page-about {
  --toc-width: 240px;
  --ch-num-size: clamp(3.25rem, 9vw, 5.5rem);
  --col-gap: clamp(1.5rem, 4vw, 3rem);

  background-color: var(--paper);
  color: var(--ink);
}

/* ---------------- 首屏 ---------------- */

.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(2.25rem, 6vw, 4.5rem) 0 clamp(2rem, 5vw, 3.5rem);
  background-color: var(--navy-800);
  color: var(--white);
  border-bottom: 1px solid var(--line-on-dark);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, rgba(214, 222, 230, 0.07) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(214, 222, 230, 0.07) 1px, transparent 1px);
  background-size: 72px 72px;
  pointer-events: none;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: min(38%, 420px);
  height: 3px;
  background: linear-gradient(90deg, var(--orange-500), var(--cyan-400));
}

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

.page-about .about-hero .breadcrumb {
  margin: 0 0 var(--sp-5);
}

.page-about .about-hero .breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.35rem;
  margin: 0;
  padding: 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: var(--fs-sm);
  letter-spacing: 0.02em;
}

.page-about .about-hero .breadcrumb__link {
  color: rgba(255, 255, 255, 0.6);
  text-decoration: none;
  transition: color var(--dur) var(--ease);
}

.page-about .about-hero .breadcrumb__link:hover,
.page-about .about-hero .breadcrumb__link:focus-visible {
  color: var(--cyan-400);
}

.page-about .about-hero .breadcrumb__current {
  color: rgba(255, 255, 255, 0.92);
}

.page-about .about-hero__eyebrow {
  margin: 0 0 var(--sp-3);
  color: var(--cyan-400);
}

.page-about .about-hero__title {
  margin: 0 0 var(--sp-5);
  max-width: 20ch;
  font-family: var(--font-mono);
  font-size: var(--fs-display-2);
  font-weight: 800;
  line-height: 1.08;
  letter-spacing: -0.02em;
  color: var(--white);
}

.page-about .about-hero__lede {
  margin: 0 0 var(--sp-7);
  max-width: 56ch;
  font-size: var(--fs-body);
  line-height: 1.85;
  color: rgba(255, 255, 255, 0.78);
}

.page-about .about-hero__metrics {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  padding: 0;
  max-width: 900px;
  list-style: none;
  background-color: var(--line-on-dark);
  border: 1px solid var(--line-on-dark);
}

.page-about .about-hero__metric {
  padding: var(--sp-4);
  background-color: var(--navy-900);
}

.page-about .about-hero__value {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 700;
  line-height: 1.1;
  font-variant-numeric: tabular-nums;
  color: var(--orange-500);
}

.page-about .about-hero__label {
  display: block;
  margin-top: 0.45rem;
  font-size: var(--fs-sm);
  line-height: 1.55;
  color: rgba(255, 255, 255, 0.6);
}

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

/* ---------------- 阅读区骨架 ---------------- */

.page-about .about-reader {
  padding: clamp(2.5rem, 6vw, 4.5rem) 0 0;
}

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

@media (min-width: 960px) {
  .page-about .about-reader__grid {
    grid-template-columns: var(--toc-width) minmax(0, 1fr);
    gap: clamp(2.5rem, 5vw, 4rem);
    align-items: start;
  }

  .page-about .about-toc {
    position: sticky;
    top: calc(var(--hdr-h) + 1.5rem);
  }
}

/* ---------------- 左侧目录 ---------------- */

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

.page-about .about-toc__label {
  margin: 0 0 var(--sp-3);
  font-family: var(--font-mono);
  font-size: var(--fs-sm);
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-muted);
}

.page-about .about-toc__list {
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line);
}

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

.page-about .about-toc__link {
  display: flex;
  align-items: baseline;
  gap: 0.6rem;
  padding: 0.7rem 0.5rem 0.7rem 0.75rem;
  border-bottom: 1px solid var(--line);
  border-left: 2px solid transparent;
  font-size: 0.875rem;
  line-height: 1.5;
  color: var(--ink-muted);
  text-decoration: none;
  transition:
    color var(--dur) var(--ease),
    background-color var(--dur) var(--ease),
    border-left-color var(--dur) var(--ease);
}

.page-about .about-toc__link:hover,
.page-about .about-toc__link:focus-visible {
  color: var(--ink);
  background-color: var(--hover-tint);
  border-left-color: var(--cyan-400);
}

.page-about .about-toc__link[data-active],
.page-about .about-toc__link[aria-current="true"] {
  color: var(--orange-500);
  border-left-color: var(--orange-500);
  font-weight: 700;
}

.page-about .about-toc__num {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--cyan-500);
  transition: color var(--dur) var(--ease);
}

.page-about .about-toc__link[data-active] .about-toc__num,
.page-about .about-toc__link[aria-current="true"] .about-toc__num {
  color: var(--orange-500);
}

.page-about .about-toc__figure {
  margin: var(--sp-5) 0 0;
}

.page-about .about-toc__figure img {
  display: block;
  width: 100%;
  height: auto;
  max-height: 340px;
  object-fit: cover;
  border: 1px solid var(--line);
  background-color: var(--navy-900);
}

.page-about .about-toc__caption {
  margin-top: 0.6rem;
  font-size: 0.75rem;
  line-height: 1.6;
  color: var(--ink-muted);
}

/* ---------------- 章节 ---------------- */

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

.page-about .chapter {
  padding: clamp(2.25rem, 5vw, 3.5rem) 0;
  border-top: 1px solid var(--line);
  scroll-margin-top: calc(var(--hdr-h) + 1.5rem);
}

.page-about .chapter:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .chapter__head {
  margin-bottom: var(--sp-5);
}

.page-about .chapter__num {
  display: block;
  margin-bottom: var(--sp-3);
  font-family: var(--font-mono);
  font-size: var(--ch-num-size);
  font-weight: 800;
  line-height: 0.9;
  letter-spacing: -0.05em;
  font-variant-numeric: tabular-nums;
  color: rgba(0, 229, 255, 0.12);
  -webkit-text-stroke: 1px var(--cyan-500);
}

.page-about .chapter__title {
  margin: 0;
  font-size: var(--fs-section);
  font-weight: 700;
  line-height: 1.32;
  letter-spacing: -0.01em;
  color: var(--navy-800);
}

.page-about .chapter__split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--sp-5);
}

@media (min-width: 1100px) {
  .page-about .chapter__split {
    grid-template-columns: minmax(0, 2fr) minmax(0, 1fr);
    gap: var(--sp-6);
  }
}

.page-about .chapter__main,
.page-about .chapter__side,
.page-about .chapter__body {
  min-width: 0;
}

.page-about .chapter__main > p,
.page-about .chapter__body > p {
  margin: 0 0 var(--sp-4);
  font-size: var(--fs-body);
  line-height: 1.85;
  color: var(--ink);
}

.page-about .chapter__main > p:last-child,
.page-about .chapter__body > p:last-child {
  margin-bottom: 0;
}

.page-about .chapter__code {
  display: inline-block;
  padding: 0.08em 0.42em;
  font-family: var(--font-mono);
  font-size: 0.88em;
  font-weight: 700;
  white-space: nowrap;
  color: var(--navy-800);
  background-color: rgba(0, 229, 255, 0.14);
}

.page-about .chapter__side {
  font-size: 0.8125rem;
  line-height: 1.75;
  color: var(--ink-muted);
}

/* ---------------- 折叠旁注 ---------------- */

.page-about .disclosure {
  background-color: var(--white);
  border: 1px solid var(--line);
}

.page-about .disclosure__summary {
  padding: var(--sp-3) var(--sp-4);
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--navy-800);
  cursor: pointer;
}

.page-about .disclosure__body {
  padding: 0 var(--sp-4) var(--sp-4);
  font-size: 0.8125rem;
  line-height: 1.8;
  color: var(--ink-muted);
}

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

/* ---------------- 阶段 ---------------- */

.page-about .phase-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin-top: var(--sp-5);
  background-color: var(--line);
  border: 1px solid var(--line);
}

@media (min-width: 760px) {
  .page-about .phase-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

.page-about .phase {
  position: relative;
  padding: var(--sp-5);
  background-color: var(--white);
  transition: background-color var(--dur) var(--ease);
}

.page-about .phase::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--orange-500);
  transition: width var(--dur) var(--ease);
}

.page-about .phase:hover::before {
  width: 100%;
}

.page-about .phase:hover {
  background-color: #FBFCFD;
}

.page-about .phase__range {
  margin: 0 0 var(--sp-3);
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  font-variant-numeric: tabular-nums;
  color: var(--orange-500);
}

.page-about .phase__title {
  margin: 0 0 var(--sp-3);
  font-size: 1.0625rem;
  font-weight: 700;
  line-height: 1.45;
  color: var(--navy-800);
}

.page-about .phase__text {
  margin: 0 0 var(--sp-4);
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--ink);
}

.page-about .phase__meta {
  margin: 0;
  padding-top: var(--sp-3);
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  line-height: 1.6;
  color: var(--ink-muted);
}

.page-about .phase-figure {
  margin: var(--sp-6) 0 0;
  padding: var(--sp-3);
  background-color: var(--navy-900);
  border: 1px solid var(--navy-700);
}

.page-about .phase-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 4 / 1;
  object-fit: cover;
}

.page-about .phase-figure__caption {
  margin-top: var(--sp-3);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  line-height: 1.6;
  color: rgba(255, 255, 255, 0.55);
}

/* ---------------- 年份刻度带 ---------------- */

.page-about .year-scale {
  margin: var(--sp-7) 0;
  padding: var(--sp-5) 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.page-about .year-scale__label {
  margin: 0 0 var(--sp-4);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-muted);
}

.page-about .year-scale__list {
  display: flex;
  gap: var(--sp-6);
  min-width: max-content;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .year-scale__item {
  position: relative;
  min-width: 152px;
  padding-left: 0.9rem;
}

.page-about .year-scale__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.15rem;
  width: 1px;
  height: 2.7rem;
  background-color: var(--cyan-500);
}

.page-about .year-scale__item--key::before {
  width: 2px;
  background-color: var(--orange-500);
}

.page-about .year-scale__year {
  display: block;
  font-family: var(--font-mono);
  font-size: 1.0625rem;
  font-weight: 700;
  line-height: 1.2;
  font-variant-numeric: tabular-nums;
  color: var(--navy-800);
}

.page-about .year-scale__item--key .year-scale__year {
  color: var(--orange-500);
}

.page-about .year-scale__note {
  display: block;
  margin-top: 0.35rem;
  font-size: 0.75rem;
  line-height: 1.55;
  color: var(--ink-muted);
}

/* ---------------- 校对步骤 ---------------- */

.page-about .steps {
  margin: var(--sp-5) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .steps__item {
  position: relative;
  margin-left: 0.35rem;
  padding: 0 0 var(--sp-5) var(--sp-5);
  border-left: 1px solid var(--line);
}

.page-about .steps__item:last-child {
  padding-bottom: 0;
  border-left-color: transparent;
}

.page-about .steps__item::before {
  content: "";
  position: absolute;
  left: -4px;
  top: 0.42rem;
  width: 7px;
  height: 7px;
  background-color: var(--paper);
  border: 1px solid var(--cyan-500);
}

.page-about .steps__step {
  margin: 0 0 0.35rem;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--cyan-500);
}

.page-about .steps__text {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--ink);
}

/* ---------------- 团队 ---------------- */

.page-about .team-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--sp-4);
  margin-top: var(--sp-5);
}

@media (min-width: 640px) {
  .page-about .team-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

.page-about .team {
  position: relative;
  padding: var(--sp-4);
  background-color: var(--white);
  border: 1px solid var(--line);
  transition:
    box-shadow var(--dur) var(--ease),
    transform var(--dur) var(--ease),
    border-color var(--dur) var(--ease);
}

.page-about .team::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--orange-500);
  transition: width var(--dur) var(--ease);
}

.page-about .team:hover::after {
  width: 100%;
}

.page-about .team:hover {
  transform: translateY(-2px);
  border-color: var(--cyan-500);
  box-shadow: 0 10px 26px rgba(10, 37, 64, 0.1);
}

.page-about .team__tag {
  margin: 0 0 var(--sp-3);
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 700;
  letter-spacing: 0.16em;
  color: var(--cyan-500);
}

.page-about .team__title {
  margin: 0 0 var(--sp-3);
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.5;
  color: var(--navy-800);
}

.page-about .team__text {
  margin: 0;
  font-size: 0.875rem;
  line-height: 1.8;
  color: var(--ink-muted);
}

/* ---------------- 请求路径 ---------------- */

.page-about .flow {
  margin-top: var(--sp-6);
  padding-top: var(--sp-5);
  border-top: 1px solid var(--line);
}

.page-about .flow__title {
  margin: 0 0 var(--sp-4);
  font-size: 1rem;
  font-weight: 700;
  color: var(--navy-800);
}

.page-about .flow__list {
  display: grid;
  gap: var(--sp-3);
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .flow__step {
  display: grid;
  grid-template-columns: 2rem minmax(0, 1fr);
  gap: var(--sp-3);
  align-items: start;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--ink);
}

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

.page-about .flow__step-num {
  display: grid;
  place-items: center;
  height: 2rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--orange-500);
  background-color: var(--white);
  border: 1px solid var(--line);
}

/* ---------------- 认证 ---------------- */

.page-about .cert-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--sp-4);
}

.page-about .cert {
  position: relative;
  padding: var(--sp-5);
  background-color: var(--navy-800);
  border: 1px solid var(--navy-700);
  transition:
    transform var(--dur) var(--ease),
    border-color var(--dur) var(--ease);
}

.page-about .cert::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 48px;
  height: 2px;
  background-color: var(--cyan-400);
  transition:
    width var(--dur) var(--ease),
    background-color var(--dur) var(--ease);
}

.page-about .cert:hover::before {
  width: 100%;
  background-color: var(--orange-500);
}

.page-about .cert:hover {
  transform: translateY(-2px);
  border-color: var(--cyan-500);
}

.page-about .cert__code {
  margin: 0 0 var(--sp-2);
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--cyan-400);
}

.page-about .cert__title {
  margin: 0 0 var(--sp-3);
  font-size: 1.0625rem;
  font-weight: 700;
  line-height: 1.45;
  color: var(--white);
}

.page-about .cert__text {
  margin: 0;
  font-size: 0.875rem;
  line-height: 1.85;
  color: rgba(255, 255, 255, 0.76);
}

.page-about .honor {
  margin-top: var(--sp-6);
  padding-top: var(--sp-5);
  border-top: 1px solid var(--line);
}

.page-about .honor__title {
  margin: 0 0 var(--sp-4);
  font-size: 1rem;
  font-weight: 700;
  color: var(--navy-800);
}

.page-about .honor__list {
  display: grid;
  gap: var(--sp-3);
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .honor__item {
  display: grid;
  grid-template-columns: 3.5rem minmax(0, 1fr);
  gap: var(--sp-3);
  align-items: baseline;
  padding-bottom: var(--sp-3);
  border-bottom: 1px solid var(--line);
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--ink);
}

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

.page-about .honor__year {
  font-family: var(--font-mono);
  font-size: 0.875rem;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  color: var(--orange-500);
}

.page-about .cert-figure {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 1 / 1;
  object-fit: cover;
  border: 1px solid var(--line);
  background-color: var(--navy-900);
}

/* ---------------- 伙伴 ---------------- */

.page-about .partner-list {
  display: grid;
  gap: var(--sp-3);
  margin: var(--sp-5) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .partner {
  padding: var(--sp-4);
  background-color: var(--white);
  border-left: 2px solid var(--navy-700);
  transition:
    border-left-color var(--dur) var(--ease),
    background-color var(--dur) var(--ease);
}

.page-about .partner:hover {
  border-left-color: var(--orange-500);
  background-color: #FBFCFD;
}

.page-about .partner__title {
  margin: 0 0 0.4rem;
  font-size: 1rem;
  font-weight: 700;
  color: var(--navy-800);
}

.page-about .partner__text {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--ink-muted);
}

/* ---------------- 统计块 ---------------- */

.page-about .stat-block {
  padding: var(--sp-4) 0;
  border-bottom: 1px solid var(--line);
}

.page-about .stat-block:first-child {
  padding-top: 0;
}

.page-about .stat-block__value {
  margin: 0 0 0.4rem;
  font-family: var(--font-mono);
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 800;
  line-height: 1;
  font-variant-numeric: tabular-nums;
  color: var(--navy-800);
}

.page-about .stat-block__unit {
  margin-left: 0.08em;
  font-size: 0.55em;
  color: var(--orange-500);
}

.page-about .stat-block__label {
  margin: 0;
  font-size: 0.8125rem;
  line-height: 1.65;
  color: var(--ink-muted);
}

/* ---------------- 结尾行动区 ---------------- */

.page-about .about-cta {
  margin-top: clamp(3rem, 7vw, 5rem);
  padding: clamp(2.5rem, 6vw, 4rem) 0;
  background-color: var(--navy-800);
  border-top: 3px solid var(--orange-500);
}

.page-about .about-cta__inner {
  display: grid;
  gap: var(--sp-6);
  align-items: center;
}

@media (min-width: 880px) {
  .page-about .about-cta__inner {
    grid-template-columns: minmax(0, 1.5fr) minmax(0, 1fr);
    gap: var(--sp-8);
  }
}

.page-about .about-cta .eyebrow {
  margin: 0 0 var(--sp-3);
  color: var(--cyan-400);
}

.page-about .about-cta__title {
  margin: 0 0 var(--sp-4);
  font-family: var(--font-mono);
  font-size: var(--fs-display-3);
  font-weight: 800;
  line-height: 1.12;
  letter-spacing: -0.02em;
  color: var(--white);
}

.page-about .about-cta__text {
  margin: 0;
  max-width: 54ch;
  font-size: var(--fs-body);
  line-height: 1.85;
  color: rgba(255, 255, 255, 0.75);
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-3);
}

/* ---------------- 焦点与动效降级 ---------------- */

.page-about a:focus-visible,
.page-about summary:focus-visible {
  outline: 2px solid var(--cyan-400);
  outline-offset: 2px;
}

@media (max-width: 640px) {
  .page-about .about-hero__title {
    max-width: none;
  }

  .page-about .about-cta__actions .btn {
    flex: 1 1 auto;
    text-align: center;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .phase::before,
  .page-about .team::after,
  .page-about .cert::before,
  .page-about .team,
  .page-about .cert {
    transition: none;
  }
}