.page-about {
  --about-measure: 66ch;
  position: relative;
  background: var(--ink);
  color: var(--paper);
  padding-bottom: clamp(40px, 7vw, 96px);
  overflow-x: hidden;
}

.page-about .about-crumb__sep {
  display: inline-block;
  margin: 0 10px;
  color: var(--stone);
  font-family: var(--font-mono);
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  max-width: 1320px;
  margin-inline: auto;
  padding: clamp(18px, 3vw, 34px) var(--gutter) 0;
}

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 26px;
  border: 2px solid var(--line);
  border-bottom: 0;
  background:
    radial-gradient(150% 170% at 4% 0%, rgba(184, 245, 61, 0.11), transparent 58%),
    radial-gradient(120% 140% at 100% 100%, rgba(196, 112, 79, 0.14), transparent 62%),
    var(--ink-2);
  padding: clamp(26px, 5vw, 58px) clamp(20px, 4vw, 52px) clamp(24px, 4vw, 44px);
}

.page-about .about-hero__copy h1 {
  margin: 14px 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(28px, 5.4vw, 56px);
  line-height: 1.18;
  letter-spacing: -0.015em;
  color: var(--paper);
  transform: skewX(-1.2deg);
  overflow-wrap: anywhere;
}

.page-about .about-hero__lead {
  margin: 20px 0 0;
  max-width: 58ch;
  font-size: clamp(15px, 1.7vw, 17px);
  line-height: 1.85;
  color: var(--mist);
}

.page-about .about-hero__marks {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px 16px;
  border-top: 2px solid var(--line);
  padding-top: 14px;
}

.page-about .about-mark {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(42px, 10vw, 88px);
  font-weight: 700;
  line-height: 0.9;
  letter-spacing: -0.03em;
  color: var(--gold);
}

.page-about .about-mark__label {
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--mist);
}

.page-about .about-hero__media {
  border: 2px solid var(--line);
  border-top: 0;
  box-shadow: var(--shadow-hard);
}

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

@media (min-width: 960px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1fr) 236px;
    align-items: end;
  }

  .page-about .about-hero__marks {
    flex-direction: column;
    align-items: flex-start;
    border-top: 0;
    border-left: 2px solid var(--line);
    padding-top: 0;
    padding-left: 22px;
  }
}

/* ---------- 章节骨架 ---------- */

.page-about .about-chapter {
  max-width: 1320px;
  margin-inline: auto;
  padding: clamp(44px, 7vw, 92px) var(--gutter) 0;
}

.page-about .about-chapter__head {
  position: relative;
  padding-top: 20px;
  border-bottom: 2px solid var(--line);
  padding-bottom: 16px;
  margin-bottom: clamp(22px, 3vw, 36px);
}

.page-about .about-chapter__head::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 26px;
  height: 3px;
  background: var(--line);
  transition: width 320ms var(--ease), background-color 320ms var(--ease);
}

.page-about .about-chapter[data-revealed] .about-chapter__head::before {
  width: 44px;
  background: var(--signal);
}

.page-about .about-chapter__idx {
  display: block;
  font-size: 12px;
  letter-spacing: 0.24em;
  color: var(--signal);
  margin-bottom: 8px;
}

.page-about .about-chapter__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(21px, 3.2vw, 36px);
  line-height: 1.24;
  letter-spacing: -0.01em;
  color: var(--paper);
}

.page-about .about-chapter__body {
  max-width: 1080px;
}

.page-about .about-prose p,
.page-about .about-intro {
  max-width: var(--about-measure);
  font-size: clamp(15px, 1.6vw, 16.5px);
  line-height: 1.85;
  color: rgba(234, 242, 239, 0.9);
  margin: 0 0 1.05em;
}

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

.page-about .about-prose--after {
  margin-top: clamp(22px, 3vw, 34px);
}

/* ---------- 使用场景 ---------- */

.page-about .about-scenes {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
}

.page-about .about-scene {
  position: relative;
  border: 2px solid var(--line);
  background: var(--ink-2);
  padding: 22px 20px 24px;
  transition: transform 200ms var(--ease), box-shadow 200ms var(--ease), border-color 200ms var(--ease);
}

.page-about .about-scene::after {
  content: "";
  position: absolute;
  right: 14px;
  top: 14px;
  width: 10px;
  height: 10px;
  border-top: 2px solid var(--stone);
  border-right: 2px solid var(--stone);
}

.page-about .about-scene:hover {
  transform: translateY(-2px);
  border-color: var(--signal-2);
  box-shadow: var(--shadow-hard);
}

.page-about .about-scene__tag {
  display: inline-block;
  margin-bottom: 12px;
}

.page-about .about-scene__title {
  margin: 0 0 10px;
  font-size: clamp(16px, 2vw, 19px);
  font-weight: 700;
  line-height: 1.45;
  color: var(--paper);
}

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

@media (min-width: 720px) {
  .page-about .about-scenes {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 18px;
  }
}

/* ---------- 内容体系 ---------- */

.page-about .about-system {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 22px;
}

.page-about .about-system__media {
  border: 2px solid var(--line);
  box-shadow: var(--shadow-soft);
}

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

.page-about .about-system__lanes {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
}

.page-about .about-lane {
  border-left: 3px solid var(--line);
  padding: 4px 0 4px 16px;
  transition: border-color 220ms var(--ease);
}

.page-about .about-lane:hover {
  border-color: var(--gold);
}

.page-about .about-lane__idx {
  display: block;
  font-size: 11px;
  letter-spacing: 0.22em;
  color: var(--clay);
  margin-bottom: 6px;
}

.page-about .about-lane__title {
  margin: 0 0 6px;
  font-size: 17px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .about-lane p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--mist);
}

@media (min-width: 900px) {
  .page-about .about-system {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: 34px;
    align-items: start;
  }
}

/* ---------- 团队分工 ---------- */

.page-about .about-crew {
  list-style: none;
  margin: clamp(26px, 4vw, 40px) 0 0;
  padding: 0;
  border-top: 2px solid var(--line);
}

.page-about .about-crew__row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 4px;
  padding: 16px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-crew__role {
  font-size: 15.5px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .about-crew__num {
  font-size: 13px;
  letter-spacing: 0.14em;
  color: var(--signal);
}

.page-about .about-crew__desc {
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--mist);
}

@media (min-width: 760px) {
  .page-about .about-crew__row {
    grid-template-columns: 132px 76px minmax(0, 1fr);
    align-items: baseline;
    gap: 20px;
  }
}

/* ---------- 版本节点 ---------- */

.page-about .about-timeline {
  margin-top: clamp(22px, 3vw, 34px);
  border-top: 2px solid var(--line);
}

.page-about .about-node {
  border-bottom: 2px solid var(--line);
}

.page-about .about-node__sum {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 20px;
  align-items: center;
  gap: 6px 14px;
  padding: 18px 4px;
  cursor: pointer;
  list-style: none;
  transition: background-color 180ms var(--ease);
}

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

.page-about .about-node__sum:hover {
  background-color: rgba(184, 245, 61, 0.06);
}

.page-about .about-node__idx {
  font-size: 11.5px;
  letter-spacing: 0.2em;
  color: var(--mist);
}

.page-about .about-node__name {
  grid-column: 1 / 2;
  font-size: clamp(15.5px, 1.9vw, 19px);
  font-weight: 700;
  line-height: 1.45;
  color: var(--paper);
}

.page-about .about-node__toggle {
  grid-column: 2 / 3;
  grid-row: 1 / 3;
  position: relative;
  width: 18px;
  height: 18px;
  align-self: center;
}

.page-about .about-node__toggle::before,
.page-about .about-node__toggle::after {
  content: "";
  position: absolute;
  background: var(--signal);
}

.page-about .about-node__toggle::before {
  left: 0;
  top: 8px;
  width: 18px;
  height: 2px;
}

.page-about .about-node__toggle::after {
  left: 8px;
  top: 0;
  width: 2px;
  height: 18px;
  transition: transform 200ms var(--ease), opacity 200ms var(--ease);
}

.page-about .about-node[open] .about-node__toggle::after {
  transform: scaleY(0);
  opacity: 0;
}

.page-about .about-node[open] .about-node__sum {
  background-color: rgba(242, 180, 65, 0.07);
}

.page-about .about-node__body {
  padding: 0 4px 22px;
  animation: about-node-open 220ms var(--ease);
}

.page-about .about-node__body p {
  margin: 0;
  max-width: var(--about-measure);
  font-size: 15px;
  line-height: 1.85;
  color: rgba(234, 242, 239, 0.82);
}

@media (min-width: 760px) {
  .page-about .about-node__sum {
    grid-template-columns: 96px minmax(0, 1fr) 20px;
    gap: 20px;
  }

  .page-about .about-node__name {
    grid-column: 2 / 3;
    grid-row: 1 / 2;
  }

  .page-about .about-node__toggle {
    grid-column: 3 / 4;
    grid-row: 1 / 2;
  }
}

@keyframes about-node-open {
  from {
    opacity: 0;
    transform: translateY(-6px);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

/* ---------- 信息来源 ---------- */

.page-about .about-source {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 24px;
}

.page-about .about-source__media {
  border: 2px solid var(--line);
  background:
    radial-gradient(120% 120% at 20% 10%, rgba(184, 245, 61, 0.12), transparent 62%),
    var(--ink-2);
  padding: 12px;
}

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

@media (min-width: 960px) {
  .page-about .about-source {
    grid-template-columns: minmax(0, 1fr) minmax(0, 400px);
    gap: 38px;
    align-items: start;
  }
}

/* ---------- 更新节奏 ---------- */

.page-about .about-rhythm {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
}

.page-about .about-rhythm__item {
  border: 2px solid var(--line);
  background:
    linear-gradient(180deg, rgba(242, 180, 65, 0.09), transparent 62%),
    var(--ink-2);
  padding: 22px 20px 24px;
  transition: transform 200ms var(--ease), border-color 200ms var(--ease);
}

.page-about .about-rhythm__item:hover {
  transform: translateY(-2px);
  border-color: var(--gold);
}

.page-about .about-rhythm__num {
  display: block;
  font-size: clamp(30px, 4vw, 44px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--gold);
}

.page-about .about-rhythm__title {
  margin: 12px 0 8px;
  font-size: 18px;
  font-weight: 700;
  color: var(--paper);
}

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

.page-about .about-rhythm__note {
  margin: 20px 0 0;
  max-width: var(--about-measure);
  font-size: 15px;
  line-height: 1.8;
  color: rgba(234, 242, 239, 0.86);
}

.page-about .about-rhythm__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 22px;
}

@media (min-width: 720px) {
  .page-about .about-rhythm {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 20px;
  }
}

/* ---------- 收尾 ---------- */

.page-about .about-cta {
  max-width: 1320px;
  margin: clamp(46px, 7vw, 90px) auto 0;
  padding: clamp(28px, 5vw, 52px) var(--gutter) 0;
  border-top: 2px solid var(--line);
}

.page-about .about-cta__title {
  margin: 12px 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(20px, 3vw, 32px);
  line-height: 1.28;
  color: var(--paper);
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}

/* ---------- 动效偏好 ---------- */

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    animation: none !important;
    transition: none !important;
  }

  .page-about .about-scene:hover,
  .page-about .about-rhythm__item:hover {
    transform: none;
  }
}