.page-about {
  display: block;
  background: var(--night-900);
  color: var(--text);
  font-family: var(--font-body);
  overflow-x: hidden;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding-top: calc(var(--header-h) + clamp(44px, 8vw, 92px));
  padding-bottom: clamp(48px, 8vw, 88px);
  background:
    radial-gradient(120% 90% at 88% 0%, rgba(182, 255, 59, 0.1) 0%, rgba(6, 12, 24, 0) 58%),
    radial-gradient(90% 70% at 0% 100%, rgba(215, 160, 95, 0.07) 0%, rgba(6, 12, 24, 0) 62%),
    var(--night-900);
  border-bottom: 1px solid var(--line-600);
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, rgba(30, 53, 80, 0.5) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(30, 53, 80, 0.32) 1px, transparent 1px);
  background-size: 72px 72px;
  -webkit-mask-image: radial-gradient(115% 100% at 82% 0%, #000 0%, transparent 72%);
  mask-image: radial-gradient(115% 100% at 82% 0%, #000 0%, transparent 72%);
  pointer-events: none;
}

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

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(30px, 6vw, 60px);
  margin-top: clamp(26px, 5vw, 46px);
}

.page-about .about-hero__title {
  margin: 16px 0 0;
  font-family: var(--font-display);
  font-size: clamp(32px, 6.2vw, 72px);
  line-height: 1.04;
  letter-spacing: -0.03em;
  font-weight: 800;
  color: var(--text);
  max-width: 15em;
}

.page-about .about-hero__lead {
  margin: clamp(16px, 3vw, 26px) 0 0;
  max-width: 54ch;
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.85;
  color: var(--muted);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(24px, 4vw, 36px);
}

.page-about .about-hero__side {
  display: grid;
  gap: 1px;
  align-self: end;
  background: var(--line-600);
  border: 1px solid var(--line-600);
  border-radius: 2px;
}

.page-about .about-signal {
  display: grid;
  gap: 6px;
  padding: 15px 18px;
  background: rgba(11, 22, 38, 0.86);
}

.page-about .about-signal__key {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--copper);
}

.page-about .about-signal__val {
  font-size: 14px;
  line-height: 1.55;
  color: var(--text);
}

/* ---------- 章节骨架 ---------- */
.page-about .about-chapter {
  position: relative;
  padding: clamp(52px, 8vw, 100px) 0;
  border-bottom: 1px solid rgba(30, 53, 80, 0.55);
}

.page-about .about-chapter--tint {
  background: var(--night-800);
}

.page-about .about-chapter__inner {
  display: grid;
  gap: clamp(18px, 3vw, 28px);
}

.page-about .about-chapter__rail {
  display: flex;
  align-items: baseline;
  gap: 14px;
}

.page-about .about-chapter__num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--dim);
}

.page-about .about-chapter__year {
  font-family: var(--font-mono);
  font-size: clamp(20px, 3vw, 28px);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1;
  color: var(--copper);
}

.page-about .about-chapter__note {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--copper);
}

.page-about .about-chapter__title {
  margin: 0 0 clamp(16px, 2.4vw, 24px);
  font-family: var(--font-display);
  font-size: clamp(23px, 3.8vw, 38px);
  line-height: 1.22;
  letter-spacing: -0.02em;
  font-weight: 800;
  color: var(--text);
  max-width: 20em;
}

.page-about .about-chapter__body > p {
  max-width: 60ch;
  margin: 0 0 1.05em;
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.85;
  color: var(--muted);
}

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

/* ---------- 场景引用 ---------- */
.page-about .about-scene {
  margin-top: clamp(22px, 3.5vw, 32px);
  padding: 18px 20px 18px 22px;
  border-left: 3px solid var(--route);
  border-radius: 0 2px 2px 0;
  background: linear-gradient(90deg, rgba(182, 255, 59, 0.1), rgba(182, 255, 59, 0) 78%);
}

.page-about .about-scene > p {
  margin: 0;
  max-width: 58ch;
  font-size: clamp(14.5px, 1.5vw, 16px);
  line-height: 1.8;
  color: var(--text);
}

/* ---------- 方法三块 ---------- */
.page-about .about-method {
  display: grid;
  gap: 1px;
  margin-top: clamp(22px, 3.5vw, 34px);
  background: var(--line-600);
  border: 1px solid var(--line-600);
  border-radius: 2px;
}

.page-about .about-method__item {
  padding: 20px 18px 22px;
  background: var(--night-900);
}

.page-about .about-chapter--tint .about-method__item {
  background: var(--night-800);
}

.page-about .about-method__title {
  margin: 0 0 8px;
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--route);
}

.page-about .about-method__item p {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--muted);
}

/* ---------- 三入口 ---------- */
.page-about .about-flow {
  display: grid;
  gap: 14px;
  margin-top: clamp(22px, 3.5vw, 34px);
}

.page-about .about-flow__step {
  display: block;
  padding: 22px 20px 24px;
  background: var(--night-700);
  border: 1px solid var(--line-600);
  border-radius: 2px;
  text-decoration: none;
  color: inherit;
  transition: border-color 0.16s var(--ease), transform 0.16s var(--ease), background-color 0.16s var(--ease);
}

.page-about .about-flow__step:hover,
.page-about .about-flow__step:focus-visible {
  border-color: rgba(182, 255, 59, 0.55);
  background: #14263e;
  transform: translateY(-3px);
}

.page-about .about-flow__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--copper);
  margin-bottom: 12px;
}

.page-about .about-flow__title {
  margin: 0 0 10px;
  font-size: 17px;
  line-height: 1.4;
  font-weight: 700;
  color: var(--text);
}

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

.page-about .about-flow__go {
  display: inline-block;
  margin-top: 16px;
  font-size: 13px;
  letter-spacing: 0.02em;
  color: var(--route);
  border-bottom: 1px solid rgba(182, 255, 59, 0.5);
  padding-bottom: 2px;
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  display: grid;
  gap: clamp(18px, 3.5vw, 30px);
  margin-top: clamp(22px, 3.5vw, 34px);
}

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

.page-about .about-team__figure img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--line-600);
  border-radius: 2px;
  object-fit: cover;
}

.page-about .about-team__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .about-team__item {
  padding: 14px 16px 16px;
  background: rgba(17, 33, 54, 0.66);
  border: 1px solid var(--line-600);
  border-radius: 2px;
  transition: border-color 0.16s var(--ease);
}

.page-about .about-team__item:hover {
  border-color: rgba(215, 160, 95, 0.55);
}

.page-about .about-team__role {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  font-size: 15px;
  font-weight: 700;
  color: var(--text);
}

.page-about .about-team__count {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.04em;
  font-variant-numeric: tabular-nums;
  color: var(--copper);
}

.page-about .about-team__desc {
  margin: 7px 0 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--muted);
}

.page-about .about-chapter__body > .about-team__coda {
  margin-top: clamp(18px, 3vw, 26px);
  padding-top: 16px;
  border-top: 1px dashed rgba(215, 160, 95, 0.35);
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 时间线 ---------- */
.page-about .about-timeline__figure {
  margin: clamp(20px, 3vw, 30px) 0 0;
}

.page-about .about-timeline__figure img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--line-600);
  border-radius: 2px;
  object-fit: cover;
}

.page-about .about-timeline {
  position: relative;
  list-style: none;
  margin: clamp(22px, 3.5vw, 34px) 0 0;
  padding: 0 0 0 22px;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(to bottom, var(--route) 0%, var(--route-deep) 55%, rgba(30, 53, 80, 0.85) 100%);
}

.page-about .about-timeline__item {
  position: relative;
}

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: -21px;
  top: 15px;
  box-sizing: border-box;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--night-900);
  border: 1px solid var(--copper);
}

.page-about .about-timeline__entry {
  border-bottom: 1px solid rgba(30, 53, 80, 0.7);
}

.page-about .about-timeline__summary {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 4px 14px;
  padding: 12px 0;
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-timeline__summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 16px;
  line-height: 1;
  color: var(--route);
}

.page-about .about-timeline__entry[open] .about-timeline__summary::after {
  content: "–";
}

.page-about .about-timeline__summary:focus-visible {
  outline: 2px solid var(--route);
  outline-offset: 3px;
}

.page-about .about-timeline__mark {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--copper);
}

.page-about .about-timeline__head {
  flex: 1 1 200px;
  font-size: 15px;
  line-height: 1.55;
  color: var(--text);
}

.page-about .about-timeline__text {
  margin: 0 0 18px;
  max-width: 58ch;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 覆盖 ---------- */
.page-about .about-coverage {
  display: grid;
  gap: clamp(20px, 3.5vw, 32px);
  margin-top: clamp(22px, 3.5vw, 34px);
}

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

.page-about .about-coverage__figure img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--line-600);
  border-radius: 2px;
  object-fit: cover;
}

.page-about .about-coverage__groups {
  display: grid;
  gap: 10px;
}

.page-about .about-group {
  padding: 14px 16px;
  border: 1px solid var(--line-600);
  border-radius: 2px;
  background: rgba(17, 33, 54, 0.55);
}

.page-about .about-group--accent {
  border-color: rgba(182, 255, 59, 0.4);
  background: rgba(78, 143, 31, 0.1);
}

.page-about .about-group__title {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  font-weight: 500;
  color: var(--route);
}

.page-about .about-group--accent .about-group__title {
  color: var(--copper);
}

.page-about .about-group__list {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 质量 ---------- */
.page-about .about-quality {
  display: grid;
  gap: 12px;
  margin-top: clamp(22px, 3.5vw, 34px);
}

.page-about .about-quality__item {
  padding: 18px 18px 20px;
  border: 1px solid var(--line-600);
  border-top: 2px solid var(--copper);
  border-radius: 0 0 2px 2px;
  background: var(--night-700);
}

.page-about .about-quality__k {
  display: inline-block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  font-variant-numeric: tabular-nums;
  color: var(--copper);
}

.page-about .about-quality__title {
  margin: 0 0 8px;
  font-size: 16px;
  line-height: 1.45;
  font-weight: 700;
  color: var(--text);
}

.page-about .about-quality__item p {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--muted);
}

/* ---------- 收束 ---------- */
.page-about .about-close {
  position: relative;
  padding: clamp(48px, 8vw, 92px) 0 clamp(56px, 9vw, 104px);
  background:
    radial-gradient(90% 120% at 78% 10%, rgba(182, 255, 59, 0.09) 0%, rgba(6, 12, 24, 0) 62%),
    var(--night-900);
  border-top: 1px solid rgba(215, 160, 95, 0.28);
}

.page-about .about-close__inner {
  position: relative;
}

.page-about .about-close__note {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--copper);
}

.page-about .about-close__title {
  margin: 0 0 16px;
  font-family: var(--font-display);
  font-size: clamp(23px, 4vw, 40px);
  line-height: 1.2;
  letter-spacing: -0.02em;
  font-weight: 800;
  color: var(--text);
  max-width: 18em;
}

.page-about .about-close__text {
  margin: 0;
  max-width: 58ch;
  font-size: clamp(15px, 1.5vw, 16px);
  line-height: 1.85;
  color: var(--muted);
}

.page-about .about-close__actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  margin-top: clamp(22px, 3.5vw, 32px);
}

.page-about .about-close__link {
  font-size: 14px;
  color: var(--muted);
  text-decoration: none;
  border-bottom: 1px solid rgba(168, 184, 202, 0.45);
  padding-bottom: 2px;
  transition: color 0.16s var(--ease), border-color 0.16s var(--ease);
}

.page-about .about-close__link:hover,
.page-about .about-close__link:focus-visible {
  color: var(--route);
  border-color: var(--route);
}

/* ---------- 响应式 ---------- */
@media (min-width: 700px) {
  .page-about .about-method {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

@media (min-width: 780px) {
  .page-about .about-flow {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    align-items: start;
  }

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

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

@media (min-width: 880px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr);
    align-items: end;
  }

  .page-about .about-chapter__inner {
    grid-template-columns: 92px minmax(0, 1fr);
    gap: clamp(30px, 4.5vw, 64px);
    align-items: start;
  }

  .page-about .about-chapter__rail {
    position: sticky;
    top: calc(var(--header-h) + 28px);
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
  }

  .page-about .about-team {
    grid-template-columns: minmax(0, 0.92fr) minmax(0, 1.08fr);
    align-items: start;
  }

  .page-about .about-coverage {
    grid-template-columns: minmax(0, 1.12fr) minmax(0, 0.88fr);
    align-items: start;
  }
}

@media (min-width: 1080px) {
  .page-about .about-chapter__inner {
    grid-template-columns: 112px minmax(0, 1fr);
  }

  .page-about .about-chapter__body {
    max-width: 940px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-flow__step,
  .page-about .about-team__item,
  .page-about .about-close__link {
    transition: none;
  }

  .page-about .about-flow__step:hover,
  .page-about .about-flow__step:focus-visible {
    transform: none;
  }
}