.page-about {
  background: var(--mist);
  color: var(--ink);
  padding-bottom: 88px;
  overflow-x: hidden;
}

.page-about .breadcrumbs {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 22px 0 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--slate);
}

.page-about .breadcrumbs a {
  color: var(--cyan-deep);
  text-decoration: none;
}

.page-about .breadcrumbs a:hover {
  color: var(--red-deep);
  text-decoration: underline;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding-top: 26px;
  padding-bottom: 0;
}

.page-about .about-hero::after {
  content: "";
  display: block;
  margin-top: 32px;
  height: 3px;
  background: linear-gradient(
    90deg,
    var(--cyan) 0 34%,
    var(--red) 34% 58%,
    var(--ink) 58% 100%
  );
}

.page-about .about-hero-grid {
  display: grid;
  gap: 26px;
  align-items: start;
}

.page-about .about-kicker {
  margin: 0 0 14px;
  font-size: 12px;
  letter-spacing: .2em;
  color: var(--cyan-deep);
}

.page-about h1 {
  margin: 0 0 20px;
  max-width: 16em;
  font-size: clamp(30px, 6.4vw, 54px);
  line-height: 1.08;
  font-weight: 900;
  letter-spacing: -.02em;
  color: var(--ink);
}

.page-about .about-lede {
  margin: 0 0 24px;
  max-width: 62ch;
  font-size: 16px;
  line-height: 1.85;
  color: #2A3B4D;
  overflow-wrap: break-word;
}

.page-about .about-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.page-about .btn-ghost {
  display: inline-flex;
  align-items: center;
  padding: 12px 22px;
  border: 2px solid var(--cyan-deep);
  background: transparent;
  color: var(--cyan-deep);
  font-size: 15px;
  font-weight: 700;
  text-decoration: none;
  box-shadow: 4px 4px 0 rgba(14, 124, 134, .24);
  transition: transform var(--dur) var(--ease), box-shadow var(--dur) var(--ease), background-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

.page-about .btn-ghost:hover {
  background: var(--cyan);
  border-color: var(--cyan);
  color: var(--ink);
  transform: translate(-2px, -2px);
  box-shadow: 6px 6px 0 rgba(14, 124, 134, .32);
}

.page-about .about-hero-panel {
  background: var(--ink);
  border: 3px solid var(--cyan);
  box-shadow: 10px 10px 0 rgba(23, 195, 201, .26);
  padding: 22px 20px 18px;
  color: var(--white);
}

.page-about .about-hero-panel .status-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 18px;
  padding: 6px 12px;
  border: 1px solid rgba(23, 195, 201, .58);
  background: rgba(23, 195, 201, .12);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--white);
}

.page-about .about-factlist {
  margin: 0;
  border-top: 1px solid rgba(185, 214, 220, .26);
}

.page-about .about-fact {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  padding: 12px 0;
  border-bottom: 1px solid rgba(185, 214, 220, .26);
}

.page-about .about-fact dt {
  font-size: 13px;
  letter-spacing: .04em;
  color: rgba(244, 247, 249, .62);
}

.page-about .about-fact dd {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 17px;
  font-weight: 700;
  color: var(--lemon);
}

/* ---------- 正文骨架 ---------- */
.page-about .about-body {
  display: grid;
  gap: 40px;
  padding-top: 52px;
}

.page-about .about-col-main {
  min-width: 0;
}

.page-about .about-col-side {
  display: grid;
  gap: 26px;
  min-width: 0;
}

.page-about .about-section {
  padding: 36px 0;
  border-top: 2px solid var(--line);
}

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

.page-about .about-index {
  margin: 0 0 10px;
  font-size: 12px;
  letter-spacing: .2em;
  color: var(--cyan-deep);
}

.page-about .about-section h2 {
  margin: 0 0 16px;
  font-size: clamp(22px, 3.6vw, 30px);
  line-height: 1.3;
  font-weight: 800;
  letter-spacing: -.02em;
  color: var(--ink);
}

.page-about .about-section .about-lead {
  margin-bottom: 22px;
}

.page-about .about-linkline {
  margin: 22px 0 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--slate);
}

.page-about .about-linkline a {
  color: var(--red-deep);
  font-weight: 700;
  text-underline-offset: 3px;
}

.page-about .about-linkline a:hover {
  color: var(--red);
}

/* ---------- 三类困扰 ---------- */
.page-about .about-issues {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 14px;
}

.page-about .about-issue {
  border: 2px solid var(--ink);
  background: var(--white);
  padding: 18px 16px 20px;
  box-shadow: 5px 5px 0 rgba(11, 21, 36, .12);
}

.page-about .about-issue .issue-num {
  display: block;
  margin-bottom: 10px;
  font-size: 13px;
  letter-spacing: .14em;
  color: var(--red-deep);
}

.page-about .about-issue h3 {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 800;
  color: var(--ink);
}

.page-about .about-issue p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--slate);
}

/* ---------- 时间线 ---------- */
.page-about .about-timeline {
  position: relative;
  margin: 0;
  padding: 0 0 0 30px;
  list-style: none;
  display: grid;
  gap: 12px;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 9px;
  top: 12px;
  bottom: 12px;
  width: 2px;
  background: linear-gradient(180deg, var(--cyan) 0%, rgba(23, 195, 201, .14) 100%);
}

.page-about .about-timeline > li {
  position: relative;
}

.page-about .about-timeline > li::before {
  content: "";
  position: absolute;
  left: -26px;
  top: 18px;
  width: 12px;
  height: 12px;
  background: var(--mist);
  border: 3px solid var(--cyan);
}

.page-about .stage {
  border: 2px solid var(--line);
  background: var(--white);
  transition: border-color var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

.page-about .stage[open] {
  border-color: var(--cyan);
  box-shadow: 6px 6px 0 rgba(23, 195, 201, .2);
}

.page-about .stage summary {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px 12px;
  padding: 14px 16px;
  cursor: pointer;
  list-style: none;
}

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

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

.page-about .stage[open] summary::after {
  content: "–";
}

.page-about .stage-tag {
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--red-deep);
}

.page-about .stage-title {
  font-size: 17px;
  font-weight: 800;
  color: var(--ink);
}

.page-about .stage-hint {
  font-size: 13.5px;
  color: var(--slate);
}

.page-about .stage-body {
  padding: 0 16px 16px;
}

.page-about .stage-body p {
  margin: 0;
  max-width: 60ch;
  font-size: 15px;
  line-height: 1.85;
  color: #2A3B4D;
}

/* ---------- 图片框 ---------- */
.page-about .about-figure {
  margin: 26px 0 0;
}

.page-about .media {
  border: 2px solid var(--line);
  background: var(--ink-2);
  overflow: hidden;
}

.page-about .media--frame {
  border: 3px solid var(--cyan);
  box-shadow: 10px 10px 0 rgba(23, 195, 201, .24);
}

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

.page-about .about-figure figcaption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  line-height: 1.7;
  letter-spacing: .02em;
  color: var(--slate);
}

.page-about .about-stage-figure {
  max-width: 340px;
}

/* ---------- 深色分区 ---------- */
.page-about .about-section--dark {
  background: var(--ink);
  border-top: 0;
  padding: 34px 22px;
  color: var(--white);
}

.page-about .about-section--dark h2 {
  color: var(--white);
}

.page-about .about-section--dark .about-index {
  color: var(--cyan);
}

.page-about .about-section--dark .about-lead {
  color: rgba(244, 247, 249, .8);
}

.page-about .about-section--dark .about-linkline {
  color: rgba(244, 247, 249, .66);
}

.page-about .about-section--dark .about-linkline a {
  color: var(--lemon);
}

.page-about .about-section--dark .about-linkline a:hover {
  color: var(--red-soft);
}

.page-about .about-section--dark .about-figure figcaption {
  color: rgba(244, 247, 249, .6);
}

.page-about .about-cats {
  display: grid;
  gap: 14px;
  margin-bottom: 26px;
}

.page-about .about-cat {
  border: 2px solid rgba(23, 195, 201, .46);
  background: var(--ink-2);
  padding: 16px 14px 18px;
}

.page-about .cat-chip {
  display: inline-block;
  margin-bottom: 10px;
  padding: 3px 9px;
  border: 1px solid currentColor;
  font-size: 12px;
  letter-spacing: .08em;
}

.page-about .about-cat--a .cat-chip {
  color: var(--red-soft);
}

.page-about .about-cat--b .cat-chip {
  color: var(--cyan);
}

.page-about .about-cat--c .cat-chip {
  color: var(--lemon);
}

.page-about .about-cat p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: rgba(244, 247, 249, .76);
}

.page-about .about-colgrid {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 8px;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
}

.page-about .about-colgrid li {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 8px 10px;
  border-left: 2px solid rgba(23, 195, 201, .5);
  font-size: 14px;
  color: rgba(244, 247, 249, .88);
}

.page-about .about-colgrid .mono {
  font-size: 11.5px;
  color: var(--cyan);
}

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

.page-about .about-speed-item {
  border: 2px solid rgba(23, 195, 201, .42);
  background: rgba(23, 195, 201, .08);
  padding: 16px;
}

.page-about .about-speed-item .num {
  display: block;
  font-family: var(--font-mono);
  font-size: 28px;
  font-weight: 700;
  line-height: 1.15;
  color: var(--lemon);
}

.page-about .about-speed-item .lbl {
  display: block;
  margin-top: 6px;
  font-size: 13.5px;
  line-height: 1.65;
  color: rgba(244, 247, 249, .74);
}

/* ---------- 团队分区 ---------- */
.page-about .about-section--accent {
  border-top: 4px solid var(--red);
}

.page-about .about-team-grid {
  display: grid;
  gap: 16px;
}

.page-about .about-team-stat {
  border-left: 3px solid var(--cyan);
  padding: 4px 0 4px 14px;
}

.page-about .about-team-stat .num {
  display: block;
  font-family: var(--font-mono);
  font-size: 30px;
  font-weight: 700;
  line-height: 1.15;
  color: var(--ink);
}

.page-about .about-team-stat .lbl {
  display: block;
  margin-top: 6px;
  font-size: 13.5px;
  line-height: 1.65;
  color: var(--slate);
}

/* ---------- 用户分布 ---------- */
.page-about .about-users-grid {
  display: grid;
  gap: 22px;
  align-items: center;
}

.page-about .about-users-copy .about-lead:last-of-type {
  margin-bottom: 0;
}

.page-about .about-users-grid .about-linkline {
  margin-top: 14px;
}

/* ---------- 侧栏目录 ---------- */
.page-about .about-toc {
  border: 2px solid var(--line);
  background: var(--white);
  padding: 18px 16px 14px;
}

.page-about .about-toc-title {
  margin: 0 0 12px;
  font-size: 11.5px;
  letter-spacing: .18em;
  color: var(--slate);
}

.page-about .about-toc ol {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 2px;
}

.page-about .about-toc a {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 8px 10px;
  border-left: 3px solid transparent;
  font-size: 14px;
  color: var(--ink);
  text-decoration: none;
  transition: border-color var(--dur) var(--ease), background-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

.page-about .about-toc a:hover,
.page-about .about-toc a:focus-visible {
  border-left-color: var(--red);
  background: rgba(226, 69, 47, .07);
  color: var(--red-deep);
}

.page-about .about-toc .toc-num {
  font-size: 12px;
  color: var(--cyan-deep);
}

/* ---------- 关键数字面板 ---------- */
.page-about .about-statpad {
  background: var(--ink-2);
  border: 3px solid var(--ink);
  box-shadow: 8px 8px 0 rgba(23, 195, 201, .3);
  padding: 20px 18px 16px;
  color: var(--white);
}

.page-about .about-statpad-title {
  margin: 0 0 12px;
  font-size: 11.5px;
  letter-spacing: .18em;
  color: var(--cyan);
}

.page-about .about-stat {
  padding: 12px 0;
  border-top: 1px solid rgba(185, 214, 220, .22);
}

.page-about .about-stat:first-of-type {
  border-top: 0;
  padding-top: 0;
}

.page-about .about-stat-num {
  display: block;
  font-family: var(--font-mono);
  font-size: 25px;
  font-weight: 700;
  line-height: 1.1;
  color: var(--lemon);
}

.page-about .about-stat-label {
  display: block;
  margin-top: 5px;
  font-size: 13px;
  line-height: 1.6;
  color: rgba(244, 247, 249, .68);
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-hero-panel {
    padding: 26px 24px 22px;
  }

  .page-about .about-section--dark {
    padding: 36px 28px;
  }
}

@media (min-width: 720px) {
  .page-about .about-issues {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

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

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

@media (min-width: 900px) {
  .page-about .about-hero {
    padding-top: 34px;
  }

  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: 48px;
  }
}

@media (min-width: 1040px) {
  .page-about .about-body {
    grid-template-columns: minmax(0, 7fr) minmax(0, 3fr);
    gap: 56px;
    align-items: start;
    padding-top: 62px;
  }

  .page-about .about-col-side {
    position: sticky;
    top: 32px;
  }

  .page-about .about-section {
    padding: 44px 0;
  }

  .page-about .about-col-main > .about-section:first-child {
    padding-top: 0;
  }

  .page-about .about-section--dark {
    padding: 44px 34px;
  }
}

@media (min-width: 1120px) {
  .page-about .about-users-grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: 36px;
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .btn-ghost,
  .page-about .stage,
  .page-about .about-toc a {
    transition: none;
  }
}