.page-about {
  --about-gap: clamp(20px, 4vw, 44px);
  position: relative;
  isolation: isolate;
  overflow-x: hidden;
  color: var(--silver);
  padding-bottom: clamp(48px, 8vw, 104px);
  background:
    radial-gradient(120% 70% at 6% -12%, rgba(0, 224, 138, 0.10), transparent 62%),
    radial-gradient(95% 60% at 100% 4%, rgba(201, 210, 218, 0.08), transparent 58%);
}

.page-about::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(to right, rgba(27, 58, 84, 0.4) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(27, 58, 84, 0.4) 1px, transparent 1px);
  background-size: 64px 64px;
  opacity: 0.45;
  -webkit-mask-image: linear-gradient(to bottom, rgba(0, 0, 0, 0.85), transparent 68%);
  mask-image: linear-gradient(to bottom, rgba(0, 0, 0, 0.85), transparent 68%);
  z-index: 0;
}

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

.page-about .breadcrumbs {
  padding-top: clamp(18px, 3vw, 34px);
  font-size: 12px;
}

.page-about a:focus-visible,
.page-about button:focus-visible {
  outline: 2px solid var(--green);
  outline-offset: 3px;
}

/* ── 封面 ── */
.page-about .about-cover {
  padding: clamp(22px, 4vw, 52px) 0 clamp(40px, 7vw, 88px);
}

.page-about .about-cover__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(28px, 5vw, 56px);
  align-items: end;
}

.page-about .about-cover .display {
  color: var(--paper);
  margin: 16px 0 0;
}

.page-about .about-cover .lede {
  margin-top: clamp(18px, 3vw, 26px);
  max-width: 48ch;
}

.page-about .about-cover__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(24px, 4vw, 38px);
}

.page-about .about-cover__meta {
  display: grid;
  gap: 20px;
  border-top: 1px dashed var(--line);
  padding-top: 22px;
}

.page-about .version-chip {
  display: inline-flex;
  align-items: baseline;
  gap: 10px;
  width: max-content;
  padding: 6px 12px;
  border: 1px solid var(--amber);
  color: var(--amber);
  font-size: 12px;
  letter-spacing: 0.2em;
}

.page-about .version-num {
  font-size: 20px;
  letter-spacing: 0.08em;
}

.page-about .meta-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
  font-size: 15px;
  line-height: 1.6;
}

.page-about .meta-list .mono {
  color: var(--green-text);
  font-size: 20px;
  margin-right: 8px;
}

.page-about .meta-note {
  margin: 0;
  font-size: 12px;
  letter-spacing: 0.24em;
  color: var(--graphite);
}

/* ── 章节骨架 ── */
.page-about .about-section {
  border-top: 1px solid var(--line);
  padding: clamp(44px, 7vw, 96px) 0;
}

.page-about .about-section__inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(18px, 3vw, 30px);
}

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

.page-about .coord-mark {
  font-size: 13px;
  letter-spacing: 0.22em;
  color: var(--green-text);
}

.page-about .coord-line {
  flex: 1 1 auto;
  height: 0;
  border-top: 1px dashed var(--line);
}

.page-about .v-note {
  writing-mode: horizontal-tb;
  font-size: 11px;
  letter-spacing: 0.3em;
  color: var(--graphite);
  white-space: nowrap;
}

.page-about .about-section__body > p,
.page-about .about-section__body > .lede {
  max-width: 64ch;
  margin-top: clamp(14px, 2vw, 20px);
}

.page-about .about-section__body .h2 {
  color: var(--paper);
  margin: 0;
}

.page-about .about-section__body .h3 {
  color: var(--silver);
  margin: 0 0 12px;
}

.page-about .about-link {
  color: var(--green-text);
  border-bottom: 1px dashed var(--green-text);
  text-decoration: none;
}

.page-about .about-link:hover {
  color: var(--green);
  border-bottom-color: var(--green);
}

/* ── 路径清单 ── */
.page-about .path-list {
  list-style: none;
  margin: clamp(22px, 3vw, 34px) 0 0;
  padding: 0;
  display: grid;
  gap: 0;
  max-width: 72ch;
}

.page-about .path-list li {
  display: grid;
  grid-template-columns: 42px minmax(0, 1fr);
  gap: 14px;
  align-items: baseline;
  padding: 16px 0;
  border-bottom: 1px dashed var(--line);
  font-size: 16px;
  line-height: 1.8;
}

.page-about .path-list li:first-child {
  border-top: 1px dashed var(--line);
}

.page-about .path-list .mono {
  color: var(--green-text);
  font-size: 13px;
}

.page-about .path-list strong {
  color: var(--paper);
  font-weight: 700;
}

/* ── 图片容器 ── */
.page-about .media-frame {
  margin: clamp(26px, 4vw, 42px) 0 0;
  border: 1px solid var(--line);
  background: var(--ink-800);
}

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

.page-about .media-frame__caption {
  padding: 12px 16px;
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--graphite);
}

/* ── 分段切换 ── */
.page-about .tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: clamp(22px, 3vw, 34px);
  padding-bottom: 16px;
  border-bottom: 1px solid var(--line);
}

.page-about .tab {
  font-family: var(--font-body);
  font-size: 14px;
  letter-spacing: 0.04em;
  color: var(--silver);
  background: var(--ink-800);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 10px 18px;
  cursor: pointer;
  transition: background-color 0.18s ease, color 0.18s ease, border-color 0.18s ease;
}

.page-about .tab:hover {
  color: var(--paper);
  border-color: var(--silver);
}

.page-about .tab[aria-selected="true"] {
  background: var(--paper);
  color: var(--ink-900);
  border-color: var(--paper);
}

.page-about .tab-panel {
  animation: about-panel-fade 0.18s ease both;
  width: 100%;
  margin-top: clamp(20px, 3vw, 30px);
  font-size: 16px;
  line-height: 1.85;
}

.page-about .tab-panel p {
  max-width: 62ch;
  margin: 0 0 14px;
}

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

.page-about .tab-panel[hidden],
.page-about .tab-panel[aria-hidden="true"] {
  display: none;
}

@keyframes about-panel-fade {
  from { opacity: 0; }
  to { opacity: 1; }
}

/* ── 版本区左右布局 ── */
.page-about .about-split {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(24px, 4vw, 48px);
  align-items: start;
}

.page-about .about-split .media-frame {
  margin-top: 0;
}

/* ── 条带与联系 ── */
.page-about .strip {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  margin-top: clamp(22px, 3vw, 34px);
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .strip__cell {
  background: var(--ink-800);
  padding: 18px 20px;
  font-size: 15px;
  line-height: 1.6;
  color: var(--paper);
}

.page-about .about-contact {
  display: grid;
  gap: 14px;
  margin-top: clamp(22px, 3vw, 32px);
}

.page-about .about-contact__item {
  display: grid;
  gap: 10px;
  padding: 16px 18px;
  border: 1px solid var(--line);
  background: var(--ink-800);
}

.page-about .about-contact__label {
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--graphite);
}

.page-about .about-contact .copy-btn {
  justify-self: start;
  padding: 2px 0;
  border: 0;
  border-bottom: 1px dashed var(--green-text);
  background: none;
  font-family: var(--font-mono);
  font-size: 15px;
  letter-spacing: 0.04em;
  color: var(--green-text);
  cursor: pointer;
  transition: color 0.18s ease, border-color 0.18s ease;
}

.page-about .about-contact .copy-btn:hover,
.page-about .about-contact .copy-btn.is-copied {
  color: var(--paper);
  border-bottom-color: var(--paper);
}

/* ── 数字栏 ── */
.page-about .stat-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: clamp(16px, 3vw, 32px);
  margin-top: clamp(26px, 4vw, 42px);
}

.page-about .stat-item {
  padding-top: 14px;
  border-top: 1px solid var(--line);
}

.page-about .stat-num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.5rem, 3.4vw, 2.2rem);
  line-height: 1.1;
  letter-spacing: 0.02em;
  color: var(--paper);
}

.page-about .stat-label {
  display: block;
  margin-top: 8px;
  font-size: 13px;
  line-height: 1.6;
  letter-spacing: 0.12em;
  color: var(--graphite);
}

/* ── 收尾 ── */
.page-about .about-closing {
  border-top: 1px solid var(--line);
  margin-top: clamp(44px, 7vw, 96px);
  padding-top: clamp(28px, 5vw, 56px);
}

.page-about .about-closing__inner {
  display: grid;
  gap: 20px;
}

.page-about .about-closing__note {
  margin: 0;
  font-size: clamp(1.1rem, 2.4vw, 1.5rem);
  line-height: 1.6;
  color: var(--paper);
}

.page-about .about-closing__links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 28px;
  font-size: 15px;
}

/* ── 平板及以上 ── */
@media (min-width: 760px) {
  .page-about .strip {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

  .page-about .about-cover__meta {
    grid-template-columns: 1fr;
  }
}

@media (min-width: 900px) {
  .page-about .about-section__inner {
    grid-template-columns: 68px minmax(0, 1fr);
    gap: clamp(26px, 4vw, 64px);
  }

  .page-about .coord-col {
    flex-direction: column;
    align-items: flex-start;
    gap: 18px;
    height: 100%;
    padding-left: 16px;
    border-left: 1px dashed var(--line);
  }

  .page-about .coord-line {
    flex: 1 1 auto;
    align-self: center;
    width: 0;
    height: auto;
    border-top: 0;
    border-left: 1px dashed var(--line);
  }

  .page-about .v-note {
    writing-mode: vertical-rl;
    letter-spacing: 0.34em;
  }

  .page-about .about-cover__meta {
    border-top: 0;
    border-left: 1px dashed var(--line);
    padding-top: 0;
    padding-left: clamp(18px, 3vw, 30px);
  }
}

@media (min-width: 1000px) {
  .page-about .about-split {
    grid-template-columns: minmax(0, 1.25fr) minmax(0, 0.85fr);
  }
}

/* ── 减少动效 ── */
@media (prefers-reduced-motion: reduce) {
  .page-about .tab-panel {
    animation: none;
  }

  .page-about .tab,
  .page-about .about-contact .copy-btn {
    transition: none;
  }
}