/* ===== 发展历程页 · page-about ===== */

.page-about {
  --about-chapter-gap: clamp(52px, 7vw, 96px);
  --about-hair: 1px solid var(--ink-600);
}

/* ---------- 首屏 ---------- */

.page-about .about-lead {
  position: relative;
  overflow: hidden;
  padding-block: clamp(104px, 15vh, 180px) clamp(44px, 7vh, 84px);
  background-image:
    linear-gradient(180deg, rgba(6, 10, 20, 0) 42%, rgba(6, 10, 20, .88) 100%),
    repeating-linear-gradient(90deg, rgba(26, 39, 64, .85) 0 1px, transparent 1px 108px),
    repeating-linear-gradient(0deg, rgba(26, 39, 64, .45) 0 1px, transparent 1px 108px);
}

.page-about .about-crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin-bottom: clamp(30px, 5vw, 54px);
  font-size: 13px;
  letter-spacing: .04em;
}

.page-about .about-crumbs .crumbs__link {
  color: var(--cyan-400);
  text-decoration: none;
  transition: color .25s var(--ease);
}

.page-about .about-crumbs .crumbs__link:hover {
  color: var(--orange-500);
  text-decoration: underline;
}

.page-about .about-crumbs__sep {
  color: var(--ink-600);
}

.page-about .about-crumbs .crumbs__item {
  color: var(--slate-300);
}

.page-about .about-lead__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(28px, 5vw, 56px);
}

.page-about .about-lead__title {
  margin: 18px 0 0;
  font-size: clamp(2.3rem, 7vw, 5.2rem);
  line-height: .98;
  letter-spacing: -.02em;
  color: var(--paper-050);
  text-shadow: 0 0 46px rgba(59, 227, 220, .16);
}

.page-about .about-lead__lede {
  margin: clamp(20px, 3vw, 30px) 0 0;
  max-width: 46ch;
  font-size: clamp(1rem, 1.4vw, 1.1rem);
  line-height: 1.78;
  color: var(--slate-300);
}

/* 首屏数字群（全页唯一一处放大数字） */

.page-about .about-figures {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(14px, 2.4vw, 34px);
  margin-top: clamp(48px, 8vw, 88px);
  padding-top: clamp(20px, 3vw, 30px);
  border-top: var(--about-hair);
}

.page-about .about-figures__item {
  min-width: 0;
}

.page-about .about-figures__val {
  display: flex;
  align-items: baseline;
  gap: 6px;
  margin: 0;
  line-height: 1;
}

.page-about .about-figures__val .mono-num {
  font-size: clamp(1.9rem, 5.4vw, 3.4rem);
  color: var(--cyan-400);
  letter-spacing: -.02em;
}

.page-about .about-figures__unit {
  font-family: var(--font-mono);
  font-size: clamp(.8rem, 1.4vw, 1rem);
  color: var(--orange-500);
}

.page-about .about-figures__key {
  margin: 10px 0 0;
  font-size: 13px;
  letter-spacing: .12em;
  color: var(--slate-300);
}

/* ---------- 主体骨架 ---------- */

.page-about .about-body {
  padding-block: clamp(48px, 7vw, 96px) clamp(56px, 8vw, 104px);
}

.page-about .about-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(30px, 5vw, 56px);
  align-items: start;
}

/* ---------- 左侧阶段刻度 ---------- */

.page-about .about-rail {
  min-width: 0;
}

.page-about .about-rail__label {
  margin: 0 0 12px;
  font-size: 11px;
  letter-spacing: .32em;
  color: var(--slate-300);
  text-transform: uppercase;
}

.page-about .about-rail__list {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0 0 10px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-rail__list::-webkit-scrollbar {
  display: none;
}

.page-about .about-rail__link {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 8px 14px;
  border: var(--about-hair);
  color: var(--slate-300);
  text-decoration: none;
  white-space: nowrap;
  font-size: 13px;
  background-color: rgba(14, 24, 48, .5);
  transition: border-color .25s var(--ease), color .25s var(--ease), background-color .25s var(--ease), transform .25s var(--ease);
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  border-color: var(--cyan-400);
  color: var(--cyan-400);
  background-color: rgba(59, 227, 220, .08);
  transform: translateX(3px);
}

.page-about .about-rail__idx {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--orange-500);
  letter-spacing: .06em;
}

.page-about .about-rail__name {
  letter-spacing: .08em;
}

/* ---------- 右侧叙述流 ---------- */

.page-about .about-flow {
  display: grid;
  gap: var(--about-chapter-gap);
  min-width: 0;
}

.page-about .about-chapter {
  position: relative;
  padding-left: clamp(22px, 3vw, 38px);
  border-left: var(--about-hair);
  scroll-margin-top: calc(var(--header-h-sm) + 28px);
}

.page-about .about-chapter::before {
  content: "";
  position: absolute;
  left: -4px;
  top: 8px;
  width: 7px;
  height: 7px;
  background: var(--cyan-400);
  box-shadow: 0 0 12px rgba(59, 227, 220, .7);
}

.page-about .about-chapter__idx {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .28em;
  color: var(--cyan-400);
}

.page-about .about-chapter__title {
  margin: 0 0 clamp(16px, 2.4vw, 26px);
  font-size: clamp(1.5rem, 3.4vw, 2.45rem);
  font-weight: 900;
  line-height: 1.14;
  letter-spacing: -.02em;
  color: var(--paper-050);
}

.page-about .about-chapter__body p {
  max-width: 60ch;
  margin: 0 0 14px;
  font-size: 1rem;
  line-height: 1.85;
  color: var(--slate-300);
}

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

.page-about .about-chapter__hi {
  color: var(--paper-100);
  border-left: 2px solid var(--orange-500);
  padding-left: 14px;
}

.page-about .about-chapter__figure {
  margin: clamp(22px, 3.4vw, 38px) 0 0;
}

.page-about .about-chapter__figure .figure__img {
  width: 100%;
  height: auto;
  object-fit: cover;
  display: block;
}

.page-about .figure__cap {
  margin-top: 10px;
  font-size: 12px;
  line-height: 1.7;
  letter-spacing: .04em;
  color: var(--slate-300);
}

/* ---------- 五次改版列表 ---------- */

.page-about .about-phases {
  margin: clamp(22px, 3.4vw, 34px) 0 0;
  padding: 0;
  list-style: none;
  border-top: var(--about-hair);
}

.page-about .about-phases__item {
  display: grid;
  grid-template-columns: 40px minmax(0, 1fr);
  gap: 6px 16px;
  padding: 20px 12px 20px 8px;
  border-bottom: var(--about-hair);
  transition: background-color .3s var(--ease);
}

.page-about .about-phases__item:hover {
  background-color: rgba(59, 227, 220, .06);
}

.page-about .about-phases__idx {
  font-family: var(--font-mono);
  font-size: 15px;
  color: var(--orange-500);
  letter-spacing: .04em;
  padding-top: 3px;
  transition: color .3s var(--ease);
}

.page-about .about-phases__item:hover .about-phases__idx {
  color: var(--cyan-400);
}

.page-about .about-phases__main {
  min-width: 0;
}

.page-about .about-phases__title {
  margin: 0 0 6px;
  font-size: 1.05rem;
  font-weight: 900;
  letter-spacing: -.01em;
  color: var(--paper-050);
}

.page-about .about-phases__desc {
  margin: 0;
  font-size: .94rem;
  line-height: 1.75;
  color: var(--slate-300);
}

.page-about .about-phases__era {
  grid-column: 2;
  align-self: start;
  justify-self: start;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--slate-300);
  border: var(--about-hair);
  padding: 3px 8px;
  white-space: nowrap;
}

/* ---------- 编辑部团队 ---------- */

.page-about .about-crew {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: clamp(22px, 3.4vw, 34px) 0 0;
  padding: 0;
  list-style: none;
  background-color: var(--ink-600);
  border: var(--about-hair);
}

.page-about .about-crew__item {
  padding: clamp(18px, 2.6vw, 28px);
  background-color: var(--ink-950);
  transition: background-color .3s var(--ease);
}

.page-about .about-crew__item:hover {
  background-color: var(--ink-800);
}

.page-about .about-crew__role {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 10px;
  font-size: 1.02rem;
  font-weight: 900;
  letter-spacing: -.01em;
  color: var(--paper-050);
}

.page-about .about-crew__num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 26px;
  height: 24px;
  padding: 0 7px;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 400;
  color: var(--ink-950);
  background-color: var(--lime-400);
}

.page-about .about-crew__duty {
  margin: 0;
  font-size: .94rem;
  line-height: 1.8;
  color: var(--slate-300);
}

/* ---------- 巡检节奏（暖纸色板） ---------- */

.page-about .about-board {
  margin-top: clamp(22px, 3.4vw, 34px);
  padding: clamp(24px, 4vw, 46px);
  background-color: var(--paper-100);
  border-left: 4px solid var(--cyan-700);
}

.page-about .about-cadence {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 3vw, 32px);
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-cadence__item {
  padding-left: 16px;
  border-left: 2px solid rgba(18, 140, 140, .28);
}

.page-about .about-cadence__lead {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: .92rem;
  letter-spacing: .04em;
  color: var(--cyan-700);
}

.page-about .about-cadence__txt {
  margin: 0;
  font-size: .96rem;
  line-height: 1.85;
  color: #3F4A5C;
}

/* ---------- 覆盖范围 ---------- */

.page-about .about-coverage {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(22px, 3.4vw, 42px);
  margin-top: clamp(6px, 1.5vw, 14px);
}

.page-about .about-coverage__text p {
  max-width: 56ch;
  margin: 0 0 14px;
  font-size: 1rem;
  line-height: 1.85;
  color: var(--slate-300);
}

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

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

.page-about .about-coverage__fig .figure__img {
  width: 100%;
  height: auto;
  object-fit: cover;
  display: block;
}

/* ---------- 归属与备案 ---------- */

.page-about .about-legal {
  margin: clamp(20px, 3vw, 30px) 0 0;
  border-top: var(--about-hair);
}

.page-about .about-legal__row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 4px;
  padding: 14px 0;
  border-bottom: var(--about-hair);
}

.page-about .about-legal__key {
  font-size: 12px;
  letter-spacing: .18em;
  color: var(--slate-300);
}

.page-about .about-legal__val {
  margin: 0;
  font-family: var(--font-mono);
  font-size: .96rem;
  line-height: 1.7;
  color: var(--paper-100);
  word-break: break-word;
}

/* ---------- 巷标条带 ---------- */

.page-about .about-lane-section {
  padding-block: clamp(44px, 6vw, 84px);
  border-top: var(--about-hair);
  background-image: linear-gradient(180deg, rgba(255, 138, 61, .07), rgba(6, 10, 20, 0) 62%);
}

.page-about .about-lane__title {
  margin: 0 0 clamp(20px, 3vw, 32px);
  font-size: clamp(1.1rem, 2vw, 1.4rem);
  font-weight: 900;
  letter-spacing: .02em;
  color: var(--paper-050);
}

.page-about .about-lane {
  display: flex;
  gap: 14px;
  overflow-x: auto;
  padding-bottom: 14px;
  scroll-snap-type: x proximity;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
}

.page-about .about-lane__item {
  flex: 0 0 auto;
  min-width: 214px;
  max-width: 292px;
  scroll-snap-align: start;
  display: grid;
  gap: 8px;
  padding: 18px 20px;
  border: var(--about-hair);
  background-color: rgba(14, 24, 48, .55);
  color: var(--paper-100);
  text-decoration: none;
  transition: border-color .25s var(--ease), background-color .25s var(--ease), transform .25s var(--ease);
}

.page-about .about-lane__item:hover,
.page-about .about-lane__item:focus-visible {
  border-color: var(--orange-500);
  background-color: rgba(255, 138, 61, .1);
  transform: translateY(-3px);
}

.page-about .about-lane__item--sign {
  border-color: rgba(59, 227, 220, .45);
}

.page-about .about-lane__item--sign:hover,
.page-about .about-lane__item--sign:focus-visible {
  border-color: var(--cyan-400);
  background-color: rgba(59, 227, 220, .1);
}

.page-about .about-lane__idx {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .2em;
  color: var(--orange-500);
}

.page-about .about-lane__name {
  font-size: 1rem;
  font-weight: 900;
  letter-spacing: -.01em;
}

.page-about .about-lane__hint {
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--slate-300);
}

/* ---------- 平板及以上 ---------- */

@media (min-width: 720px) {
  .page-about .about-phases__item {
    grid-template-columns: 48px minmax(0, 1fr) 132px;
    align-items: start;
    gap: 6px 20px;
  }

  .page-about .about-phases__era {
    grid-column: 3;
    justify-self: end;
  }

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

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

  .page-about .about-legal__row {
    grid-template-columns: 148px minmax(0, 1fr);
    align-items: baseline;
    gap: 20px;
  }
}

/* ---------- 桌面：左刻度粘性固定 ---------- */

@media (min-width: 1080px) {
  .page-about .about-shell {
    grid-template-columns: 176px minmax(0, 1fr);
    column-gap: clamp(30px, 4vw, 68px);
  }

  .page-about .about-rail {
    position: sticky;
    top: calc(var(--header-h-sm) + 36px);
    align-self: start;
  }

  .page-about .about-rail__list {
    flex-direction: column;
    gap: 2px;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .about-rail__link {
    width: 100%;
    border: 0;
    border-left: var(--about-hair);
    background-color: transparent;
    padding: 11px 0 11px 15px;
    white-space: normal;
  }

  .page-about .about-rail__link:hover,
  .page-about .about-rail__link:focus-visible {
    border-left-color: var(--cyan-400);
    background-color: rgba(59, 227, 220, .06);
  }

  .page-about .about-coverage {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.08fr);
    align-items: start;
  }

  .page-about .about-lead__grid {
    grid-template-columns: minmax(0, 1.62fr) minmax(0, .78fr);
    align-items: end;
  }

  .page-about .about-figures {
    grid-template-columns: repeat(3, minmax(0, 200px));
    justify-content: start;
    column-gap: clamp(28px, 5vw, 72px);
  }
}

/* ---------- 动效降级 ---------- */

@media (prefers-reduced-motion: reduce) {
  .page-about .about-rail__link,
  .page-about .about-phases__item,
  .page-about .about-crew__item,
  .page-about .about-lane__item {
    transition: none;
  }

  .page-about .about-rail__link:hover,
  .page-about .about-lane__item:hover {
    transform: none;
  }
}