.page-about {
  padding-block-start: 0;
  --about-rail-w: 208px;
}

/* ---------- Hero ---------- */
.page-about .about-hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  padding: calc(var(--header-h) + clamp(26px, 5vw, 56px)) 0 clamp(42px, 7vw, 86px);
  border-bottom: 1px solid var(--line);
  background:
    radial-gradient(78% 68% at 88% 2%, rgba(53, 167, 255, 0.20), transparent 62%),
    radial-gradient(66% 58% at 4% 0%, rgba(200, 255, 61, 0.13), transparent 58%),
    linear-gradient(180deg, #04120E 0%, var(--ink) 74%);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset-inline: -10%;
  bottom: -46%;
  height: 62%;
  background: linear-gradient(90deg, transparent, rgba(30, 74, 58, 0.55), transparent);
  transform: rotate(-4deg);
  pointer-events: none;
  z-index: -1;
}

.page-about .about-hero__grid {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--gutter);
  display: grid;
  gap: clamp(30px, 5vw, 52px);
}

.page-about .about-hero__lead .breadcrumb {
  margin-bottom: 18px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
}

.page-about .about-hero__lead .plate {
  margin-bottom: 14px;
}

.page-about .about-hero h1 {
  margin: 0 0 18px;
  max-width: 15ch;
  color: var(--paper);
  font-family: var(--font-display);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.02;
}

.page-about .about-hero .lede {
  max-width: 46ch;
  color: var(--silver);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(22px, 3vw, 32px);
}

/* 版本索引卡 */
.page-about .about-hero__index {
  position: relative;
  padding: clamp(16px, 3vw, 22px);
  border: 2px solid var(--line);
  background: linear-gradient(158deg, rgba(13, 42, 33, 0.96), rgba(6, 22, 17, 0.98));
  box-shadow: var(--shadow-hard);
}

.page-about .about-hero__index::before {
  content: "";
  position: absolute;
  top: -2px;
  left: -2px;
  width: 74px;
  height: 2px;
  background: var(--lime);
}

.page-about .about-hero__index-title {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--mist);
}

.page-about .ver-list {
  display: grid;
  gap: 8px;
}

.page-about .ver-card {
  border: 1px solid var(--line);
  background: rgba(7, 26, 20, 0.72);
  transition: border-color 0.25s var(--ease), background-color 0.25s var(--ease), transform 0.25s var(--ease);
}

.page-about .ver-card:hover,
.page-about .ver-card:focus-within {
  border-color: var(--lime);
  background: rgba(13, 42, 33, 0.95);
  transform: translateX(2px);
}

.page-about .ver-card__head {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 14px;
  text-decoration: none;
  color: var(--silver);
}

.page-about .ver-card__v {
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 600;
  color: var(--lime);
  letter-spacing: 0.04em;
}

.page-about .ver-card__t {
  flex: 1 1 auto;
  font-size: 13px;
  color: var(--silver);
}

.page-about .ver-card__more {
  display: grid;
  grid-template-rows: 1fr;
  transition: grid-template-rows 0.4s var(--ease);
}

.page-about .ver-card__more > div {
  overflow: hidden;
  min-height: 0;
}

.page-about .ver-card__more p {
  margin: 0;
  padding: 0 14px 14px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--mist);
  border-top: 1px dashed var(--line);
  padding-top: 10px;
  margin-inline: 14px;
  padding-inline: 0;
}

/* ---------- Body 分屏 ---------- */
.page-about .about-body {
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--gutter);
  padding-block: clamp(14px, 3vw, 26px) clamp(46px, 8vw, 96px);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
}

/* ---------- 左侧章节索引 ---------- */
.page-about .about-rail {
  border-bottom: 1px solid var(--line);
  padding-bottom: 14px;
}

.page-about .about-rail__label {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--mist);
}

.page-about .about-rail__list {
  display: flex;
  gap: 6px;
  overflow-x: auto;
  padding-bottom: 6px;
  scrollbar-width: thin;
}

.page-about .chapter-link {
  flex: 0 0 auto;
  padding: 7px 11px;
  border: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.03em;
  color: var(--mist);
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease), background-color 0.2s var(--ease);
}

.page-about .chapter-link:hover,
.page-about .chapter-link:focus-visible {
  color: var(--lime);
  border-color: var(--lime);
}

.page-about .chapter-link.is-active,
.page-about .chapter-link[aria-current="true"] {
  color: var(--ink);
  background: var(--lime);
  border-color: var(--lime);
}

/* ---------- 章节 ---------- */
.page-about .chapter {
  padding-block: clamp(34px, 5vw, 68px);
  border-top: 1px solid var(--line);
}

.page-about .chapter:first-child {
  border-top: 0;
  padding-top: clamp(24px, 4vw, 40px);
}

.page-about .chapter__head {
  display: grid;
  gap: 10px;
  margin-bottom: clamp(20px, 3vw, 30px);
}

.page-about .chapter__head .plate {
  color: var(--lime);
}

.page-about .chapter__head h2 {
  margin: 0;
  color: var(--paper);
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: -0.015em;
}

.page-about .chapter__head .lede {
  max-width: 52ch;
  color: var(--silver);
  font-size: 15px;
}

.page-about .chapter__body p {
  margin: 0 0 16px;
  color: var(--silver);
  line-height: 1.62;
  max-width: 62ch;
}

.page-about .pull-quote {
  margin: 26px 0;
  padding: 16px 0 16px 20px;
  border-left: 3px solid var(--lime);
  font-family: var(--font-editorial);
  font-size: clamp(20px, 3vw, 26px);
  line-height: 1.4;
  color: var(--paper);
}

.page-about .panel {
  margin: 24px 0;
  max-width: 60ch;
  padding: 16px 18px;
  border: 1px solid var(--line);
  border-left: 3px solid var(--pulse);
  background: rgba(13, 42, 33, 0.72);
}

.page-about .panel--amber {
  border-left-color: var(--amber);
}

.page-about .panel__title {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--amber);
}

.page-about .panel__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.65;
  color: var(--silver);
}

/* ---------- 方法论切换 ---------- */
.page-about .method {
  position: relative;
  display: grid;
  gap: 18px;
}

.page-about .method__input {
  position: absolute;
  width: 1px;
  height: 1px;
  opacity: 0;
  pointer-events: none;
}

.page-about .method__bar {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .method__bar label {
  cursor: pointer;
  padding: 9px 15px;
  border: 1px solid var(--line);
  background: rgba(13, 42, 33, 0.6);
  color: var(--silver);
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.06em;
  transition: color 0.2s var(--ease), background-color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.page-about .method__bar label:hover {
  border-color: var(--lime);
  color: var(--lime);
}

.page-about .method__input:focus-visible ~ .method__bar label {
  outline: 2px dashed var(--lime);
  outline-offset: 2px;
}

.page-about #method-1:checked ~ .method__bar label[for="method-1"],
.page-about #method-2:checked ~ .method__bar label[for="method-2"],
.page-about #method-3:checked ~ .method__bar label[for="method-3"],
.page-about #method-4:checked ~ .method__bar label[for="method-4"] {
  background: var(--lime);
  border-color: var(--lime);
  color: var(--ink);
}

.page-about .method__panel {
  display: none;
}

.page-about #method-1:checked ~ .method__panels .method__panel:nth-child(1),
.page-about #method-2:checked ~ .method__panels .method__panel:nth-child(2),
.page-about #method-3:checked ~ .method__panels .method__panel:nth-child(3),
.page-about #method-4:checked ~ .method__panels .method__panel:nth-child(4) {
  display: block;
  animation: about-fade 0.35s var(--ease) both;
}

@keyframes about-fade {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}

.page-about .method__panel {
  padding: clamp(16px, 3vw, 24px);
  border: 1px solid var(--line);
  border-left: 3px solid var(--lime);
  background: linear-gradient(120deg, rgba(13, 42, 33, 0.9), rgba(7, 26, 20, 0.7));
}

.page-about .method__panel h3 {
  margin: 0 0 10px;
  color: var(--paper);
}

.page-about .method__panel p {
  margin: 0 0 12px;
  color: var(--silver);
  font-size: 14.5px;
  line-height: 1.65;
  max-width: 58ch;
}

.page-about .method__panel .note {
  margin: 0;
  padding-left: 12px;
  border-left: 1px dashed var(--line);
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--mist);
}

.page-about .method__media {
  margin: 6px 0 0;
}

/* ---------- 媒体框 ---------- */
.page-about .media-frame {
  position: relative;
  border: 1px solid var(--line);
  background: var(--panel);
  overflow: hidden;
}

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

.page-about .media-frame .media-frame__caption {
  margin: 0;
  padding: 10px 14px;
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 11.5px;
  line-height: 1.55;
  color: var(--mist);
}

/* ---------- 版本历程 ---------- */
.page-about .version-strip {
  margin-bottom: clamp(22px, 4vw, 34px);
}

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

.page-about .version-side {
  align-self: start;
}

.page-about .timeline {
  list-style: none;
  margin: 0;
  padding: 0 0 0 26px;
  position: relative;
  display: grid;
  gap: 20px;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: linear-gradient(180deg, var(--lime), rgba(30, 74, 58, 0.25));
}

.page-about .timeline__item {
  position: relative;
  padding: 12px 14px;
  border: 1px solid var(--line);
  background: rgba(13, 42, 33, 0.55);
}

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  left: -26px;
  top: 18px;
  width: 10px;
  height: 10px;
  background: var(--ink);
  border: 2px solid var(--lime);
  transform: rotate(45deg);
}

.page-about .timeline__v {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--amber);
}

.page-about .timeline__t {
  margin: 0 0 8px;
  color: var(--paper);
  font-size: 16px;
  font-weight: 700;
}

.page-about .timeline__item p:last-child {
  margin: 0;
  color: var(--silver);
  font-size: 14px;
  line-height: 1.65;
}

/* ---------- 团队 ---------- */
.page-about .stat-grid {
  display: grid;
  gap: 10px;
  grid-template-columns: repeat(auto-fit, minmax(130px, 1fr));
  margin-bottom: clamp(20px, 3vw, 28px);
}

.page-about .stat {
  padding: 14px 16px;
  border: 1px solid var(--line);
  background: rgba(13, 42, 33, 0.6);
}

.page-about .stat__num {
  margin: 0 0 4px;
  font-family: var(--font-mono);
  font-size: 28px;
  font-weight: 600;
  line-height: 1;
  color: var(--amber);
}

.page-about .stat__label {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.05em;
  color: var(--mist);
}

.page-about .team-list {
  display: grid;
  gap: 12px;
  margin-bottom: 20px;
}

.page-about .team-card {
  padding: 16px 18px;
  border: 1px solid var(--line);
  border-left: 3px solid var(--lime);
  background: linear-gradient(100deg, rgba(200, 255, 61, 0.06), rgba(7, 26, 20, 0.4) 60%);
}

.page-about .team-card h3 {
  margin: 0 0 8px;
  color: var(--paper);
}

.page-about .team-card p {
  margin: 0;
  color: var(--silver);
  font-size: 14px;
  line-height: 1.65;
}

/* ---------- 协作生态 ---------- */
.page-about .partner-grid {
  display: grid;
  gap: 10px;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  margin-bottom: 22px;
}

.page-about .partner-cell {
  padding: 16px;
  border: 1px solid var(--line);
  background: rgba(13, 42, 33, 0.5);
  position: relative;
}

.page-about .partner-cell::after {
  content: "";
  position: absolute;
  right: 10px;
  top: 10px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--pulse);
  box-shadow: 0 0 0 4px rgba(53, 167, 255, 0.14);
}

.page-about .partner-cell__num {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 26px;
  font-weight: 600;
  line-height: 1;
  color: var(--lime);
}

.page-about .partner-cell__txt {
  margin: 0;
  font-size: 13px;
  line-height: 1.6;
  color: var(--silver);
}

/* ---------- 场景 ---------- */
.page-about .scene-list {
  display: grid;
  gap: 12px;
}

.page-about .scene-card {
  padding: 16px 18px;
  border: 1px solid var(--line);
  border-top: 3px solid var(--pulse);
  background: rgba(7, 26, 20, 0.55);
}

.page-about .scene-card:nth-child(2) {
  border-top-color: var(--amber);
}

.page-about .scene-card:nth-child(3) {
  border-top-color: var(--lime);
}

.page-about .scene-card:nth-child(4) {
  border-top-color: var(--mist);
}

.page-about .scene-card h3 {
  margin: 0 0 8px;
  color: var(--paper);
  font-size: 16px;
}

.page-about .scene-card p {
  margin: 0;
  color: var(--silver);
  font-size: 14px;
  line-height: 1.65;
}

/* ---------- 荣誉 ---------- */
.page-about .honor-list {
  display: grid;
  gap: 12px;
  margin-bottom: 20px;
}

.page-about .honor-item {
  display: grid;
  gap: 8px;
  padding: 16px 18px;
  border: 2px solid var(--line);
  background: rgba(13, 42, 33, 0.5);
}

.page-about .honor-item p {
  margin: 0;
  color: var(--silver);
  font-size: 14px;
  line-height: 1.65;
}

.page-about .honor-item .tag {
  justify-self: start;
}

/* ---------- 下一步 ---------- */
.page-about .next-grid {
  display: grid;
  gap: 12px;
  margin-bottom: clamp(24px, 4vw, 34px);
}

.page-about .next-item {
  padding: 16px 18px;
  border-left: 3px solid var(--lime-deep);
  background: rgba(13, 42, 33, 0.45);
}

.page-about .next-item h3 {
  margin: 0 0 8px;
  color: var(--paper);
}

.page-about .next-item p {
  margin: 0;
  color: var(--silver);
  font-size: 14px;
  line-height: 1.65;
}

.page-about .about-cta {
  padding: clamp(20px, 4vw, 34px);
  border: 2px solid var(--lime);
  background:
    radial-gradient(90% 120% at 0% 0%, rgba(200, 255, 61, 0.16), transparent 62%),
    linear-gradient(150deg, rgba(13, 42, 33, 0.95), rgba(6, 22, 17, 0.98));
  box-shadow: var(--shadow-hard);
}

.page-about .about-cta h3 {
  margin: 0 0 10px;
  color: var(--paper);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(20px, 3vw, 26px);
}

.page-about .about-cta p {
  margin: 0 0 18px;
  max-width: 56ch;
  color: var(--silver);
  font-size: 14.5px;
  line-height: 1.7;
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

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

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

  .page-about .honor-item {
    grid-template-columns: auto minmax(0, 1fr);
    align-items: start;
    gap: 14px;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
    align-items: start;
  }

  .page-about .ver-card__more {
    grid-template-rows: 0fr;
  }

  .page-about .ver-card:hover .ver-card__more,
  .page-about .ver-card:focus-within .ver-card__more {
    grid-template-rows: 1fr;
  }

  .page-about .ver-card__more > div {
    transition: opacity 0.3s var(--ease);
    opacity: 0;
  }

  .page-about .ver-card:hover .ver-card__more > div,
  .page-about .ver-card:focus-within .ver-card__more > div {
    opacity: 1;
  }
}

@media (min-width: 960px) {
  .page-about .about-body {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: clamp(28px, 4.5vw, 64px);
    align-items: start;
  }

  .page-about .about-rail {
    border-bottom: 0;
    padding-bottom: 0;
    border-right: 1px solid var(--line);
    padding-right: 18px;
  }

  .page-about .about-rail__inner {
    position: sticky;
    top: calc(var(--header-h) + 26px);
  }

  .page-about .about-rail__list {
    flex-direction: column;
    overflow: visible;
    gap: 4px;
    padding-bottom: 0;
  }

  .page-about .chapter-link {
    white-space: normal;
    border-color: transparent;
    border-left: 2px solid var(--line);
    background: transparent;
    padding: 8px 10px;
  }

  .page-about .chapter-link.is-active,
  .page-about .chapter-link[aria-current="true"] {
    color: var(--lime);
    background: rgba(200, 255, 61, 0.08);
    border-color: transparent;
    border-left-color: var(--lime);
  }
}

@media (min-width: 1020px) {
  .page-about .version-layout {
    grid-template-columns: minmax(0, 0.72fr) minmax(0, 1fr);
    align-items: start;
  }

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

  .page-about .method__media {
    margin-top: 10px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ver-card,
  .page-about .ver-card__more,
  .page-about .ver-card__more > div,
  .page-about .chapter-link {
    transition: none;
  }

  .page-about #method-1:checked ~ .method__panels .method__panel:nth-child(1),
  .page-about #method-2:checked ~ .method__panels .method__panel:nth-child(2),
  .page-about #method-3:checked ~ .method__panels .method__panel:nth-child(3),
  .page-about #method-4:checked ~ .method__panels .method__panel:nth-child(4) {
    animation: none;
  }
}