/* ============================================================
   page-about · 怀旧单元（档案体系 / 团队 / 勘误传统）
   作用域：.page-about
   ============================================================ */

.page-about {
  --ab-block: clamp(56px, 8.5vw, 124px);
  --ab-body-w: 36rem;
  position: relative;
}

.page-about :focus-visible {
  outline: 2px solid var(--orange);
  outline-offset: 3px;
}

/* ---------- 首屏 ---------- */
.page-about .about-intro {
  position: relative;
  overflow: hidden;
  padding: clamp(22px, 4vw, 52px) 0 clamp(44px, 7vw, 92px);
}

.page-about .about-intro::before {
  content: "";
  position: absolute;
  z-index: 0;
  top: -12%;
  right: -24%;
  width: min(62vw, 720px);
  aspect-ratio: 1 / 1;
  background: var(--violet);
  opacity: .13;
  transform: rotate(14deg);
  clip-path: polygon(0 0, 100% 0, 100% 68%, 0 100%);
  pointer-events: none;
}

.page-about .about-intro::after {
  content: "";
  position: absolute;
  z-index: 0;
  left: -10%;
  bottom: 6%;
  width: min(34vw, 320px);
  height: 18px;
  background: repeating-linear-gradient(90deg, var(--cyan) 0 8px, transparent 8px 16px);
  opacity: .38;
  pointer-events: none;
}

.page-about .about-intro__grid {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(32px, 5vw, 64px);
  align-items: end;
}

.page-about .about-intro__text .breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: clamp(18px, 3vw, 34px);
  font-size: var(--fs-index);
  letter-spacing: var(--track-index);
  color: var(--mist);
}

.page-about .about-intro__text .breadcrumb a {
  color: var(--mist);
  text-decoration: none;
  border-bottom: 1px solid var(--line-strong);
}

.page-about .about-intro__text .breadcrumb a:hover {
  color: var(--violet);
  border-bottom-color: var(--cyan);
}

.page-about .about-intro__text > .eyebrow {
  display: block;
  margin: 0 0 16px;
  color: var(--violet);
}

.page-about .display--xl {
  margin: 0;
  font-size: clamp(2.15rem, 6.6vw, 5rem);
  font-weight: 200;
  line-height: 1.08;
  letter-spacing: -.02em;
  color: var(--ink);
}

.page-about .about-intro__lede {
  max-width: var(--ab-body-w);
  margin: clamp(18px, 3vw, 28px) 0 0;
  font-size: var(--fs-body);
  line-height: var(--lh-body);
  color: var(--ink);
}

.page-about .about-figures {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 2px;
  margin-top: clamp(26px, 4vw, 44px);
  border: 2px solid var(--ink);
  background: var(--ink);
}

.page-about .about-figure {
  display: grid;
  gap: 6px;
  align-content: start;
  padding: 14px 12px 16px;
  background: var(--paper);
}

.page-about .about-figure__num {
  font-family: var(--font-mono);
  font-size: clamp(1.2rem, 3.4vw, 1.9rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--violet);
}

.page-about .about-figure__label {
  font-size: .74rem;
  line-height: 1.5;
  letter-spacing: .04em;
  color: var(--mist);
}

/* ---------- 通用图片卡 ---------- */
.page-about .about-shot {
  margin: 0;
  border: 2px solid var(--ink);
  background: var(--ink-2);
  box-shadow: var(--shadow-hard);
}

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

.page-about .about-shot figcaption {
  padding: 10px 14px;
  border-top: 2px solid var(--ink);
  background: var(--ink-2);
  color: var(--paper);
  font-family: var(--font-mono);
  font-size: var(--fs-index);
  letter-spacing: var(--track-index);
}

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

.page-about .about-intro__shot img {
  aspect-ratio: 16 / 9;
}

/* ---------- 区块标题 ---------- */
.page-about .about-block {
  padding-top: var(--ab-block);
  padding-bottom: var(--ab-block);
}

.page-about .about-head {
  max-width: 42rem;
  margin-bottom: clamp(26px, 4vw, 52px);
}

.page-about .about-head .eyebrow {
  display: block;
  margin: 0 0 14px;
  color: var(--violet);
}

.page-about .about-head h2 {
  margin: 0;
  color: var(--ink);
}

.page-about .about-head::after {
  content: "";
  display: block;
  width: 58px;
  height: 2px;
  margin-top: 20px;
  background: var(--cyan);
}

.page-about .about-head__sub {
  margin: 14px 0 0;
  font-size: .95rem;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .display--sm {
  font-size: clamp(1.5rem, 3.8vw, 2.6rem);
  font-weight: 200;
  line-height: 1.22;
  letter-spacing: -.015em;
}

.page-about .about-head--invert h2,
.page-about .about-head--invert .eyebrow {
  color: var(--paper);
}

.page-about .about-head--invert .eyebrow {
  color: var(--cyan);
}

.page-about .about-head--invert::after {
  background: var(--orange);
}

.page-about .about-head--invert .about-head__sub {
  color: rgba(245, 239, 226, .68);
}

.page-about .about-body p {
  max-width: var(--ab-body-w);
  font-size: var(--fs-body);
  line-height: var(--lh-body);
  color: var(--ink);
}

.page-about .about-body p + p {
  margin-top: 1em;
}

.page-about .about-link {
  color: var(--violet);
  text-decoration: none;
  border-bottom: 2px solid var(--cyan);
  padding-bottom: 1px;
}

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

/* ---------- 01 缘起 ---------- */
.page-about .about-cols {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(28px, 4vw, 52px);
  align-items: start;
}

.page-about .about-gate {
  display: grid;
  gap: 12px;
}

.page-about .about-gate__item {
  display: grid;
  gap: 6px;
  padding: 18px 18px 20px;
  border: 2px solid var(--ink);
  background: var(--paper-2);
  color: var(--ink);
  text-decoration: none;
  transition: transform var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-gate__item:hover {
  transform: translate(-2px, -2px);
  border-color: var(--violet);
}

.page-about .about-gate__idx {
  font-size: var(--fs-index);
  letter-spacing: var(--track-index);
  color: var(--mist);
}

.page-about .about-gate__name {
  font-size: 1.08rem;
  font-weight: 700;
  letter-spacing: .01em;
}

.page-about .about-gate__desc {
  font-size: .86rem;
  line-height: 1.65;
  color: var(--mist);
}

/* ---------- 02 编号 ---------- */
.page-about .about-code__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(28px, 4vw, 56px);
  align-items: center;
}

.page-about .about-code__shot img {
  aspect-ratio: 3 / 2;
}

.page-about .about-code__parts {
  list-style: none;
  margin: clamp(30px, 5vw, 56px) 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .about-code__part {
  position: relative;
  display: grid;
  gap: 8px;
  padding: 20px 18px 30px;
  border: 2px solid var(--ink);
  background: var(--paper);
}

.page-about .about-code__part p {
  margin: 0;
  font-size: .9rem;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .about-code__seg {
  font-size: clamp(1.5rem, 4vw, 2.1rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--violet);
}

.page-about .about-code__name {
  font-size: .95rem;
  font-weight: 700;
  color: var(--ink);
}

.page-about .about-code__slot {
  position: absolute;
  right: 12px;
  bottom: 9px;
  font-size: .68rem;
  letter-spacing: .1em;
  color: var(--mist);
}

/* ---------- 03 八类文档 ---------- */
.page-about .about-docs__list {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
}

.page-about .about-doc {
  border: 2px solid var(--ink);
  background: var(--paper);
}

.page-about .about-doc[open] {
  background: var(--paper-2);
  border-color: var(--violet);
}

.page-about .about-doc__summary {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 15px 16px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-doc__idx {
  font-size: var(--fs-index);
  letter-spacing: var(--track-index);
  color: var(--orange);
  flex: none;
}

.page-about .about-doc__name {
  font-size: 1rem;
  font-weight: 700;
  color: var(--ink);
}

.page-about .about-doc__hint {
  margin-left: auto;
  font-size: .76rem;
  letter-spacing: .04em;
  color: var(--mist);
  flex: none;
}

.page-about .about-doc__body {
  margin: 0;
  padding: 0 16px 18px;
  font-size: .9rem;
  line-height: 1.75;
  color: var(--mist);
  border-top: 1px dashed var(--line-strong);
  padding-top: 14px;
}

/* ---------- 04 时间线 ---------- */
.page-about .about-line .about-head::after {
  background: var(--orange);
}

.page-about .about-timeline {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: clamp(14px, 2.2vw, 26px);
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 15px;
  top: 14px;
  bottom: 14px;
  width: 2px;
  background: linear-gradient(180deg, var(--violet), var(--cyan) 52%, var(--orange));
  opacity: .6;
}

.page-about .about-timeline__item {
  position: relative;
  padding-left: 46px;
}

.page-about .about-timeline__dot {
  position: absolute;
  left: 8px;
  top: 15px;
  width: 16px;
  height: 16px;
  background: var(--violet);
  border: 2px solid var(--ink);
}

.page-about .about-timeline__item:nth-child(2n) .about-timeline__dot {
  background: var(--cyan);
}

.page-about .about-timeline__item:nth-child(3n) .about-timeline__dot {
  background: var(--orange);
}

.page-about .about-node {
  border: 2px solid var(--ink);
  background: var(--paper);
}

.page-about .about-node[open] {
  background: var(--glass);
  border-color: var(--violet);
}

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

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

.page-about .about-node__summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 1.05rem;
  color: var(--violet);
}

.page-about .about-node[open] .about-node__summary::after {
  content: "—";
  color: var(--orange);
}

.page-about .about-node__num {
  font-size: var(--fs-index);
  letter-spacing: var(--track-index);
  color: var(--mist);
  flex: none;
}

.page-about .about-node__title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--ink);
  line-height: 1.5;
}

.page-about .about-node__body {
  margin: 0;
  padding: 14px 16px 18px;
  border-top: 1px dashed var(--line-strong);
  font-size: .9rem;
  line-height: 1.75;
  color: var(--mist);
}

/* ---------- 05 团队 ---------- */
.page-about .about-team__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(28px, 4vw, 56px);
  align-items: start;
}

.page-about .about-team__shot img {
  aspect-ratio: 10 / 7;
}

.page-about .about-roster {
  list-style: none;
  margin: clamp(32px, 5vw, 60px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 2px;
  background: var(--ink);
  border: 2px solid var(--ink);
}

.page-about .about-roster__item {
  display: grid;
  grid-template-columns: auto 1fr;
  grid-template-areas:
    "n role"
    "n duty";
  gap: 2px 16px;
  padding: 16px 18px;
  background: var(--paper);
  align-items: center;
}

.page-about .about-roster__n {
  grid-area: n;
  font-size: clamp(1.6rem, 4vw, 2.3rem);
  font-weight: 700;
  line-height: 1;
  color: var(--moss);
}

.page-about .about-roster__role {
  grid-area: role;
  font-size: .98rem;
  font-weight: 700;
  color: var(--ink);
}

.page-about .about-roster__duty {
  grid-area: duty;
  font-size: .82rem;
  line-height: 1.6;
  color: var(--mist);
}

/* ---------- 06 勘误与盘点（深色区） ---------- */
.page-about .about-log {
  position: relative;
  overflow: hidden;
}

.page-about .about-log::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: repeating-linear-gradient(
    180deg,
    rgba(245, 239, 226, .05) 0 1px,
    transparent 1px 6px
  );
  pointer-events: none;
}

.page-about .about-log__grid {
  position: relative;
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(16px, 2.6vw, 30px);
}

.page-about .about-log__card {
  padding: clamp(22px, 3vw, 34px);
  border: 2px solid rgba(245, 239, 226, .22);
  border-radius: 0;
  color: var(--paper);
}

.page-about .about-log__num {
  display: block;
  margin: 0 0 12px;
  font-size: clamp(1.6rem, 4.4vw, 2.5rem);
  font-weight: 700;
  letter-spacing: -.02em;
  color: var(--cyan);
}

.page-about .about-log__title {
  margin: 0 0 12px;
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--paper);
}

.page-about .about-log__body {
  margin: 0;
  font-size: .92rem;
  line-height: 1.8;
  color: rgba(245, 239, 226, .8);
}

/* ---------- 07 社群共建 ---------- */
.page-about .about-community__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(28px, 4vw, 56px);
  align-items: start;
}

.page-about .about-community__steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .about-community__step {
  display: grid;
  gap: 6px;
  padding: 18px 18px 20px;
  border: 2px solid var(--ink);
  background: var(--paper);
  border-left: 8px solid var(--orange);
}

.page-about .about-community__step:nth-child(2) {
  border-left-color: var(--violet);
}

.page-about .about-community__step:nth-child(3) {
  border-left-color: var(--moss);
}

.page-about .about-community__idx {
  font-size: var(--fs-index);
  letter-spacing: var(--track-index);
  color: var(--mist);
}

.page-about .about-community__name {
  font-size: 1rem;
  font-weight: 700;
  color: var(--ink);
}

.page-about .about-community__desc {
  font-size: .86rem;
  line-height: 1.7;
  color: var(--mist);
}

/* ---------- 收束 CTA ---------- */
.page-about .about-cta {
  padding: clamp(36px, 6vw, 72px) 0 clamp(56px, 8vw, 104px);
}

.page-about .about-cta__inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(22px, 3.4vw, 40px);
  align-items: center;
  padding: clamp(22px, 3.4vw, 40px) clamp(20px, 3vw, 40px);
  border: 2px solid var(--ink);
  background: var(--paper-2);
  box-shadow: var(--shadow-hard);
}

.page-about .about-cta__copy .eyebrow {
  display: block;
  margin: 0 0 12px;
  color: var(--violet);
}

.page-about .about-cta__copy h2 {
  margin: 0 0 12px;
  color: var(--ink);
}

.page-about .about-cta__copy p {
  margin: 0;
  max-width: 34rem;
  font-size: .95rem;
  line-height: 1.75;
  color: var(--mist);
}

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

/* ============================================================
   响应式
   ============================================================ */

@media (min-width: 640px) {
  .page-about .about-docs__list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

@media (min-width: 900px) {
  .page-about .about-intro__grid {
    grid-template-columns: minmax(0, 1.12fr) minmax(0, .88fr);
    gap: clamp(36px, 4.5vw, 76px);
  }

  .page-about .about-cols {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, .9fr);
  }

  .page-about .about-code__grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr);
  }

  .page-about .about-code__parts {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 16px;
    padding-bottom: 44px;
  }

  .page-about .about-code__part:nth-child(2) {
    transform: translateY(22px);
  }

  .page-about .about-code__part:nth-child(3) {
    transform: translateY(44px);
  }

  .page-about .about-timeline__item:nth-child(2) {
    margin-left: 5%;
  }

  .page-about .about-timeline__item:nth-child(3) {
    margin-left: 10%;
  }

  .page-about .about-timeline__item:nth-child(4) {
    margin-left: 4%;
  }

  .page-about .about-timeline__item:nth-child(5) {
    margin-left: 9%;
  }

  .page-about .about-timeline__item:nth-child(6) {
    margin-left: 2%;
  }

  .page-about .about-team__grid {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr);
  }

  .page-about .about-roster {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-log__grid {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr);
    align-items: start;
  }

  .page-about .about-log__card--shift {
    transform: translateY(38px);
  }

  .page-about .about-community__grid {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, .9fr);
  }

  .page-about .about-cta__inner {
    grid-template-columns: minmax(0, 1.3fr) auto;
  }
}

@media (min-width: 1180px) {
  .page-about .about-docs__list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 14px;
  }
}

@media (max-width: 420px) {
  .page-about .about-figures {
    grid-template-columns: 1fr;
  }

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

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

@media (prefers-reduced-motion: reduce) {
  .page-about .about-gate__item,
  .page-about .about-code__part,
  .page-about .about-log__card--shift,
  .page-about .about-roster__item {
    transition: none;
    transform: none;
  }
}