.page-about {
  --about-rail-width: 0px;
  --about-hairline: #1F2A34;
  --about-panel: rgba(20, 28, 36, 0.82);
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding-top: clamp(20px, 4vw, 40px);
  padding-bottom: clamp(48px, 8vw, 104px);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: -30% -10% auto -10%;
  height: 480px;
  background:
    radial-gradient(58% 100% at 22% 0%, rgba(46, 127, 184, 0.22), transparent 72%),
    radial-gradient(48% 86% at 88% 8%, rgba(201, 150, 60, 0.13), transparent 74%);
  pointer-events: none;
}

.page-about .about-hero .shell {
  position: relative;
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(28px, 4vw, 48px);
  margin-top: clamp(24px, 4vw, 44px);
}

.page-about .about-hero__kicker {
  margin: 0;
  font-family: var(--font-serif);
  font-size: 15px;
  letter-spacing: 0.18em;
  color: var(--gold-500);
}

.page-about .about-hero__title {
  margin: 14px 0 20px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(31px, 6.4vw, 54px);
  line-height: 1.14;
  letter-spacing: -0.02em;
  color: var(--text);
}

.page-about .about-hero__intro {
  margin: 0;
  max-width: 60ch;
  font-size: 16.5px;
  line-height: 1.95;
  color: var(--text-dim);
}

.page-about .about-hero__panel {
  position: relative;
  padding: 26px 24px 22px;
  border: 1px solid var(--about-hairline);
  border-radius: var(--radius-card);
  background: var(--about-panel);
  backdrop-filter: blur(10px);
}

.page-about .about-hero__panel::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 24px;
  width: 56px;
  height: 3px;
  border-radius: 0 0 3px 3px;
  background: var(--gold-500);
}

.page-about .about-hero__panel-title {
  margin: 0 0 18px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.14em;
  color: var(--text-dim);
}

.page-about .about-hero__facts {
  margin: 0;
  display: grid;
  gap: 14px;
}

.page-about .about-hero__facts > div {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--about-hairline);
}

.page-about .about-hero__facts > div:last-child {
  padding-bottom: 0;
  border-bottom: 0;
}

.page-about .about-hero__facts dt {
  font-size: 14px;
  color: var(--text-dim);
}

.page-about .about-hero__facts dd {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 17px;
  color: var(--gold-300);
}

/* ---------- 章节骨架 ---------- */

.page-about .about-chapter {
  padding-block: clamp(56px, 9vw, 120px);
}

.page-about .about-chapter+.about-chapter {
  border-top: 1px solid var(--about-hairline);
}

.page-about .about-chapter__grid {
  display: grid;
  gap: clamp(12px, 2vw, 28px);
}

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

.page-about .about-chapter__rail::after {
  content: "";
  flex: 1;
  height: 1px;
  background: var(--about-hairline);
}

.page-about .about-chapter__index {
  font-family: var(--font-mono);
  font-size: 24px;
  line-height: 1;
  color: rgba(201, 150, 60, 0.78);
}

.page-about .about-head__kicker {
  margin: 0 0 10px;
  font-family: var(--font-serif);
  font-size: 15px;
  letter-spacing: 0.16em;
  color: var(--gold-500);
}

.page-about .about-head__title {
  margin: 0 0 16px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(25px, 4.2vw, 36px);
  line-height: 1.26;
  letter-spacing: -0.01em;
  color: var(--text);
}

.page-about .about-head__desc {
  margin: 0;
  max-width: 64ch;
  font-size: 16px;
  line-height: 1.95;
  color: var(--text-dim);
}

.page-about .about-textlink {
  color: var(--blue-400);
  text-decoration: none;
  border-bottom: 1px solid rgba(95, 179, 232, 0.42);
}

.page-about .about-textlink:hover {
  border-bottom-color: var(--gold-300);
  color: var(--gold-300);
}

/* ---------- 时间轴 ---------- */

.page-about .about-timeline__list {
  list-style: none;
  margin: clamp(28px, 4vw, 44px) 0 0;
  padding: 0;
  display: grid;
  gap: 18px;
}

.page-about .about-timeline__item {
  position: relative;
  padding-left: 30px;
}

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: 8px;
  top: 26px;
  bottom: -22px;
  width: 2px;
  background: var(--about-hairline);
}

.page-about .about-timeline__item:last-child::before {
  display: none;
}

.page-about .about-timeline__item::after {
  content: "";
  position: absolute;
  left: 1px;
  top: 17px;
  width: 16px;
  height: 16px;
  box-sizing: border-box;
  border: 3px solid var(--blue-600);
  border-radius: 50%;
  background: var(--ink-900);
}

.page-about .about-stage {
  border: 1px solid var(--about-hairline);
  border-radius: var(--radius-card);
  background: var(--about-panel);
  overflow: hidden;
}

.page-about .about-stage__summary {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px 16px;
  padding: 18px 20px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-stage__summary::marker {
  content: "";
}

.page-about .about-stage__summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 18px;
  line-height: 1;
  color: var(--gold-500);
}

.page-about .about-stage[open]>.about-stage__summary::after {
  content: "−";
  color: var(--gold-300);
}

.page-about .about-stage__summary:focus-visible {
  outline: 2px solid var(--gold-300);
  outline-offset: -2px;
}

.page-about .about-stage__year {
  font-family: var(--font-mono);
  font-size: 13.5px;
  letter-spacing: 0.05em;
  color: var(--gold-300);
}

.page-about .about-stage__name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 17px;
  color: var(--text);
}

.page-about .about-stage__body {
  padding: 0 20px 20px;
  font-size: 15.5px;
  line-height: 1.95;
  color: var(--text-dim);
}

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

/* ---------- 图片 ---------- */

.page-about .about-figure {
  margin: clamp(28px, 4vw, 44px) 0 0;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  border: 1px solid var(--about-hairline);
  border-radius: var(--radius-card);
}

.page-about .about-figure figcaption {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.8;
  color: var(--text-dim);
}

/* ---------- 版本 ---------- */

.page-about .about-version-cards {
  display: grid;
  gap: 16px;
  margin-top: clamp(28px, 4vw, 44px);
}

.page-about .about-version-card {
  position: relative;
  padding: 24px 22px;
  border: 1px solid var(--about-hairline);
  border-radius: var(--radius-card);
  background: var(--ink-800);
}

.page-about .about-version-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 22px;
  width: 40px;
  height: 3px;
  border-radius: 0 0 3px 3px;
  background: var(--blue-600);
}

.page-about .about-version-card__tag {
  display: inline-block;
  margin-bottom: 14px;
  padding: 4px 10px;
  border: 1px solid rgba(201, 150, 60, 0.4);
  border-radius: var(--radius-pill);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--gold-300);
}

.page-about .about-version-card__title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 19px;
  color: var(--text);
}

.page-about .about-version-card p {
  margin: 0;
  font-size: 15px;
  line-height: 1.9;
  color: var(--text-dim);
}

.page-about .about-version-foot {
  margin: clamp(22px, 3vw, 32px) 0 0;
  font-size: 15.5px;
  line-height: 1.95;
  color: var(--text-dim);
}

.page-about .about-version-foot .version-code {
  font-family: var(--font-mono);
  font-size: 16px;
  color: var(--gold-300);
}

/* ---------- 地区覆盖（浅色专区） ---------- */

.page-about .about-region {
  padding-block: clamp(56px, 9vw, 120px);
}

.page-about .about-region .about-head__kicker {
  color: #1B5E86;
}

.page-about .about-region .about-head__title {
  color: var(--light-ink);
}

.page-about .about-region .about-head__desc {
  color: #46545F;
}

.page-about .about-region__grid {
  display: grid;
  gap: clamp(28px, 4vw, 52px);
  margin-top: clamp(28px, 4vw, 48px);
}

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

.page-about .about-region__figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  border-radius: var(--radius-card);
  border: 1px solid rgba(22, 32, 42, 0.12);
  background: #E7EDF3;
}

.page-about .about-region__figure figcaption {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.8;
  color: #5A6773;
}

.page-about .about-region__lead {
  margin: 0 0 20px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 18px;
  line-height: 1.6;
  color: var(--light-ink);
}

.page-about .about-region__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.page-about .about-region__item {
  padding: 9px 15px;
  border: 1px solid rgba(22, 32, 42, 0.16);
  border-radius: var(--radius-pill);
  background: #FFFFFF;
  font-size: 14px;
  line-height: 1.4;
  color: var(--light-ink);
  transition: background-color 200ms var(--ease-out), color 200ms var(--ease-out), border-color 200ms var(--ease-out);
}

.page-about .about-region__item:hover {
  border-color: var(--gold-500);
  background: #16202A;
  color: var(--gold-300);
}

.page-about .about-region__item--home {
  border-color: rgba(46, 127, 184, 0.5);
  background: rgba(46, 127, 184, 0.1);
}

.page-about .about-region__note {
  margin: 24px 0 0;
  font-size: 15px;
  line-height: 1.95;
  color: #46545F;
}

/* ---------- 团队 ---------- */

.page-about .about-team__grid {
  display: grid;
  gap: clamp(28px, 4vw, 48px);
  margin-top: clamp(28px, 4vw, 44px);
}

.page-about .about-bar+.about-bar {
  margin-top: 28px;
}

.page-about .about-bar__head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 10px;
}

.page-about .about-bar__label {
  font-size: 15px;
  color: var(--text);
}

.page-about .about-bar__num {
  font-family: var(--font-mono);
  font-size: 16px;
  color: var(--gold-300);
}

.page-about .about-bar__track {
  height: 10px;
  border-radius: var(--radius-pill);
  background: var(--ink-700);
  overflow: hidden;
}

.page-about .about-bar__fill {
  display: block;
  height: 100%;
  border-radius: var(--radius-pill);
  transition: filter 220ms var(--ease-out);
}

.page-about .about-bar__fill--support {
  width: 48%;
  background: var(--blue-600);
}

.page-about .about-bar__fill--ops {
  width: 52%;
  background: var(--gold-500);
}

.page-about .about-bar:hover .about-bar__fill {
  filter: brightness(1.18);
}

.page-about .about-bar__desc {
  margin: 12px 0 0;
  font-size: 14.5px;
  line-height: 1.9;
  color: var(--text-dim);
}

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

/* ---------- 服务标准 ---------- */

.page-about .about-stats {
  display: grid;
  gap: 16px;
  margin-top: clamp(28px, 4vw, 44px);
}

.page-about .about-stat {
  position: relative;
  padding: 26px 22px 22px;
  border: 1px solid var(--about-hairline);
  border-radius: var(--radius-card);
  background: var(--ink-800);
}

.page-about .about-stat::before {
  content: "";
  position: absolute;
  top: 0;
  left: 22px;
  width: 46px;
  height: 3px;
  border-radius: 0 0 3px 3px;
  background: var(--gold-500);
}

.page-about .about-stat__num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(30px, 5vw, 40px);
  line-height: 1;
  color: var(--text);
}

.page-about .about-stat__num small {
  margin-left: 4px;
  font-size: 0.5em;
  color: var(--text-dim);
}

.page-about .about-stat__label {
  margin: 14px 0 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--text-dim);
}

.page-about .about-standard-notes {
  margin-top: clamp(24px, 3vw, 36px);
  display: grid;
  gap: 16px;
  padding-left: 20px;
  border-left: 2px solid rgba(46, 127, 184, 0.45);
}

.page-about .about-standard-notes__item {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.95;
  color: var(--text-dim);
}

/* ---------- 底部延伸 ---------- */

.page-about .about-tail {
  padding-block: clamp(48px, 7vw, 96px);
  border-top: 1px solid var(--about-hairline);
}

.page-about .about-tail__label {
  margin: 0 0 20px;
  font-family: var(--font-serif);
  font-size: 15px;
  letter-spacing: 0.16em;
  color: var(--gold-500);
}

.page-about .about-next {
  display: grid;
  gap: 14px;
}

.page-about .about-next__link {
  display: block;
  padding: 22px;
  border: 1px solid var(--about-hairline);
  border-radius: var(--radius-card);
  text-decoration: none;
  background: transparent;
  transition: border-color 220ms var(--ease-out), background-color 220ms var(--ease-out);
}

.page-about .about-next__link:hover {
  border-color: var(--gold-500);
  background: var(--ink-800);
}

.page-about .about-next__link:focus-visible {
  outline: 2px solid var(--gold-300);
  outline-offset: 2px;
}

.page-about .about-next__label {
  display: block;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 17px;
  color: var(--text);
}

.page-about .about-next__desc {
  display: block;
  margin-top: 10px;
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--text-dim);
}

/* ---------- 响应式 ---------- */

@media (min-width: 640px) {
  .page-about .about-version-cards {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

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

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: start;
  }

  .page-about .about-hero__panel {
    margin-top: 56px;
  }

  .page-about .about-chapter__grid {
    grid-template-columns: 76px minmax(0, 1fr);
    gap: clamp(20px, 3vw, 40px);
  }

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

  .page-about .about-chapter__rail::after {
    display: none;
  }

  .page-about .about-chapter__index {
    display: block;
    font-size: 40px;
    color: rgba(201, 150, 60, 0.6);
  }

  .page-about .about-head__desc,
  .page-about .about-chapter__body>.about-head,
  .page-about .about-chapter__body>.about-timeline__list,
  .page-about .about-chapter__body>.about-version-foot,
  .page-about .about-chapter__body>.about-standard-notes {
    max-width: 78ch;
  }

  .page-about .about-region__grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 6fr);
    align-items: start;
  }

  .page-about .about-team__grid {
    grid-template-columns: minmax(0, 6fr) minmax(0, 5fr);
    align-items: center;
  }

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

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

@media (min-width: 1100px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 6fr) minmax(0, 5fr);
    column-gap: clamp(48px, 6vw, 96px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-bar__fill,
  .page-about .about-region__item,
  .page-about .about-next__link {
    transition: none;
  }
}