/* ===== 品牌价值页 · page-about ===== */

.page-about {
  --ab-rail: 116px;
  --ab-rail-top: 96px;
}

/* —— 首屏 —— */
.page-about .ab-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(14px, 2.4vw, 28px) 0 clamp(36px, 5vw, 72px);
  border-bottom: 1px solid var(--line-hair);
}

.page-about .ab-hero::before {
  content: "";
  position: absolute;
  top: -34%;
  right: -12%;
  width: clamp(240px, 44vw, 640px);
  aspect-ratio: 1 / 1;
  border-radius: 50%;
  background: radial-gradient(circle at 58% 42%, rgba(232, 178, 60, .16), rgba(11, 22, 34, 0) 68%);
  pointer-events: none;
}

.page-about .ab-hero::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: min(38%, 320px);
  height: 1px;
  background: linear-gradient(90deg, var(--signal-red), rgba(240, 68, 56, 0));
}

.page-about .ab-hero__inner {
  position: relative;
  z-index: 1;
  display: grid;
  gap: 16px;
  max-width: 940px;
}

.page-about .ab-hero h1 {
  margin: 0;
  font-family: var(--f-display);
  font-weight: 900;
  font-size: clamp(32px, 6vw, 72px);
  line-height: 1.06;
  letter-spacing: -.02em;
  color: var(--text-strong);
}

.page-about .ab-hero__lede {
  margin: 0;
  max-width: 66ch;
  font-size: var(--t17);
  line-height: 1.78;
  color: var(--text-soft);
}

.page-about .ab-hero__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 6px;
}

.page-about .ab-hero__chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 15px;
  border: 1px solid var(--line-hair);
  border-radius: var(--r-pill);
  background: rgba(18, 34, 47, .6);
  font-size: var(--t12);
  letter-spacing: .08em;
  color: var(--text-soft);
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

.page-about .ab-hero__chip::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--state-live);
  box-shadow: 0 0 0 3px rgba(47, 191, 155, .18);
}

.page-about .ab-hero__chip:nth-child(2)::before {
  background: var(--warm-gold);
  box-shadow: 0 0 0 3px rgba(232, 178, 60, .18);
}

.page-about .ab-hero__chip:nth-child(3)::before {
  background: var(--signal-red);
  box-shadow: 0 0 0 3px rgba(240, 68, 56, .18);
}

.page-about .ab-hero__chip:hover {
  border-color: var(--warm-gold);
  color: var(--text-strong);
}

/* —— 章节骨架 —— */
.page-about .ab-chapter {
  padding: clamp(38px, 5.6vw, 84px) 0;
  border-bottom: 1px solid var(--line-hair);
}

.page-about .ab-chapter--paper {
  padding-bottom: clamp(30px, 4.4vw, 64px);
}

.page-about .ab-chapter--last {
  border-bottom: 0;
}

.page-about .ab-chapter__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 20px;
}

.page-about .ab-chapter__rail {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding-left: 14px;
  border-left: 1px solid var(--line-hair);
}

.page-about .ab-chapter__num {
  font-family: var(--f-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--t30);
  font-weight: 800;
  line-height: 1;
  letter-spacing: .02em;
  color: var(--warm-gold);
}

.page-about .ab-chapter__name {
  font-size: var(--t12);
  letter-spacing: .22em;
  color: var(--state-expired);
}

.page-about .ab-chapter__body {
  min-width: 0;
  max-width: 68ch;
}

.page-about .ab-chapter__body--wide {
  max-width: none;
}

.page-about .ab-chapter__body h2 {
  margin: 0 0 16px;
  font-family: var(--f-display);
  font-weight: 800;
  font-size: clamp(25px, 3.2vw, 40px);
  line-height: 1.16;
  letter-spacing: -.01em;
  color: var(--text-strong);
}

.page-about .ab-chapter__body p {
  margin: 0 0 16px;
  font-size: var(--t17);
  line-height: 1.78;
  color: var(--text-soft);
}

.page-about .ab-chapter__body .ab-lead {
  margin-bottom: 22px;
  font-size: var(--t22);
  font-weight: 500;
  line-height: 1.6;
  color: var(--text-strong);
}

.page-about .ab-chapter__body a {
  color: var(--warm-gold);
  text-decoration: none;
  border-bottom: 1px solid rgba(232, 178, 60, .42);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .ab-chapter__body a:hover,
.page-about .ab-chapter__body a:focus-visible {
  color: var(--text-strong);
  border-bottom-color: var(--signal-red);
}

/* —— 三个麻烦 —— */
.page-about .ab-problems {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
}

.page-about .ab-problem {
  padding: 22px 0 22px 18px;
  border-top: 1px solid var(--line-hair);
  border-left: 2px solid transparent;
  transition: border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .ab-problem:last-child {
  border-bottom: 1px solid var(--line-hair);
}

.page-about .ab-problem:hover {
  border-left-color: var(--signal-red);
  background: linear-gradient(90deg, rgba(240, 68, 56, .07), rgba(11, 22, 34, 0) 62%);
}

.page-about .ab-problem__idx {
  font-family: var(--f-mono);
  font-size: var(--t12);
  letter-spacing: .18em;
  color: var(--signal-red);
}

.page-about .ab-problem h3 {
  margin: 8px 0 10px;
  font-family: var(--f-display);
  font-size: var(--t22);
  font-weight: 700;
  line-height: 1.36;
  color: var(--text-strong);
}

.page-about .ab-chapter__body .ab-problem__fix {
  position: relative;
  margin-bottom: 0;
  padding-left: 20px;
  font-size: var(--t14);
  line-height: 1.75;
  color: var(--text-strong);
}

.page-about .ab-problem__fix::before {
  content: "⟶";
  position: absolute;
  left: 0;
  color: var(--state-live);
}

/* —— 暖纸数据区 —— */
.page-about .ab-paper {
  position: relative;
  overflow: hidden;
  padding: clamp(24px, 4.2vw, 60px);
  border-radius: var(--r-lg);
  background: var(--paper-warm);
  color: var(--ink-on-paper);
}

.page-about .ab-paper::after {
  content: "";
  position: absolute;
  right: -8%;
  bottom: -42%;
  width: clamp(180px, 34vw, 420px);
  aspect-ratio: 1 / 1;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(240, 68, 56, .11), rgba(244, 237, 225, 0) 70%);
  pointer-events: none;
}

.page-about .ab-paper__kicker {
  margin: 0;
  font-size: var(--t12);
  letter-spacing: .24em;
  color: var(--signal-red);
}

.page-about .ab-paper__title {
  margin: 10px 0 28px;
  font-family: var(--f-display);
  font-weight: 800;
  font-size: clamp(24px, 3vw, 38px);
  line-height: 1.16;
  letter-spacing: -.01em;
  color: var(--ink-on-paper);
}

.page-about .ab-stats {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 20px;
}

.page-about .ab-stat {
  padding-top: 16px;
  border-top: 1px solid var(--paper-2);
}

.page-about .ab-stat__num {
  display: block;
  font-family: var(--f-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 800;
  font-size: clamp(32px, 4.6vw, 52px);
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--ink-on-paper);
}

.page-about .ab-stat__unit {
  display: block;
  margin-top: 9px;
  font-size: var(--t12);
  letter-spacing: .14em;
  color: var(--signal-red);
}

.page-about .ab-stat p {
  margin: 10px 0 0;
  font-size: var(--t14);
  line-height: 1.72;
  color: var(--ink-on-paper);
  opacity: .72;
}

/* —— 时间轴 —— */
.page-about .ab-figure {
  margin: 6px 0 28px;
  border-radius: var(--r-md);
  overflow: hidden;
}

.page-about .ab-figure .c5-figure__img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .ab-timeline {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .ab-node {
  display: grid;
  grid-template-columns: 78px minmax(0, 1fr);
  gap: 16px;
  padding: 20px 0;
  border-top: 1px solid var(--line-hair);
  transition: border-color var(--dur) var(--ease);
}

.page-about .ab-node:last-child {
  border-bottom: 1px solid var(--line-hair);
}

.page-about .ab-node__year {
  font-family: var(--f-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--t22);
  font-weight: 800;
  line-height: 1.1;
  color: var(--state-expired);
  transition: color var(--dur) var(--ease);
}

.page-about .ab-node h3 {
  margin: 0 0 6px;
  font-family: var(--f-display);
  font-size: var(--t17);
  font-weight: 700;
  line-height: 1.5;
  color: var(--text-strong);
}

.page-about .ab-chapter__body .ab-node p {
  margin: 0;
  font-size: var(--t14);
  line-height: 1.75;
}

.page-about .ab-node:hover,
.page-about .ab-node:focus-within {
  border-top-color: var(--warm-gold);
}

.page-about .ab-node:hover .ab-node__year,
.page-about .ab-node:focus-within .ab-node__year {
  color: var(--warm-gold);
}

.page-about .ab-node.is-now .ab-node__year {
  color: var(--warm-gold);
}

.page-about .ab-node.is-now .ab-node__year::after {
  content: "当前";
  display: block;
  margin-top: 8px;
  font-family: var(--f-body);
  font-size: 10px;
  font-weight: 500;
  letter-spacing: .2em;
  color: var(--state-live);
}

/* —— 团队 —— */
.page-about .ab-split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--gap);
  margin-top: 26px;
}

.page-about .ab-split__text {
  min-width: 0;
}

.page-about .ab-shifts {
  display: grid;
  gap: 12px;
  margin-top: 24px;
}

.page-about .ab-shift {
  padding: 15px 18px;
  border: 1px solid var(--line-hair);
  border-radius: var(--r-md);
  background: linear-gradient(180deg, rgba(18, 34, 47, .92), rgba(15, 29, 41, .62));
  transition: border-color var(--dur) var(--ease), transform var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

.page-about .ab-shift:hover {
  transform: translateY(-2px);
  border-color: var(--warm-gold);
  box-shadow: 0 12px 28px rgba(0, 0, 0, .34);
}

.page-about .ab-shift__head {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
}

.page-about .ab-shift__time {
  font-family: var(--f-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--t14);
  letter-spacing: .04em;
  color: var(--warm-gold);
}

.page-about .ab-shift__name {
  font-size: var(--t12);
  letter-spacing: .2em;
  color: var(--state-live);
}

.page-about .ab-split .ab-shift p {
  margin: 8px 0 0;
  font-size: var(--t14);
  line-height: 1.7;
}

.page-about .ab-figure--team {
  margin: 0;
}

/* —— 合作图 —— */
.page-about .ab-figure--bleed {
  margin: clamp(28px, 4vw, 52px) 0 0;
  border-radius: var(--r-lg);
}

/* —— 下一步 —— */
.page-about .ab-next {
  list-style: none;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
  margin: 26px 0 0;
  padding: 0;
}

.page-about .ab-next li {
  display: grid;
}

.page-about .ab-next a {
  display: grid;
  gap: 9px;
  height: 100%;
  padding: 20px 22px;
  border: 1px solid var(--line-hair);
  border-radius: var(--r-md);
  background: rgba(18, 34, 47, .55);
  text-decoration: none;
  transition: border-color var(--dur) var(--ease), transform var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .ab-next a:hover,
.page-about .ab-next a:focus-visible {
  transform: translateY(-2px);
  border-color: var(--warm-gold);
  background: rgba(18, 34, 47, .95);
}

.page-about .ab-next__t {
  font-family: var(--f-display);
  font-size: var(--t22);
  font-weight: 800;
  color: var(--text-strong);
}

.page-about .ab-next__t::after {
  content: "⟶";
  display: inline-block;
  margin-left: 10px;
  color: var(--signal-red);
  transition: transform var(--dur) var(--ease);
}

.page-about .ab-next a:hover .ab-next__t::after {
  transform: translateX(5px);
}

.page-about .ab-next__d {
  font-size: var(--t14);
  line-height: 1.72;
  color: var(--text-soft);
}

/* —— 响应式 —— */
@media (min-width: 620px) {
  .page-about .ab-stats {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 24px 30px;
  }
}

@media (min-width: 760px) {
  .page-about .ab-next {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .page-about .ab-chapter__grid {
    grid-template-columns: var(--ab-rail) minmax(0, 1fr);
    gap: clamp(28px, 4vw, 72px);
  }

  .page-about .ab-chapter__rail {
    position: sticky;
    top: var(--ab-rail-top);
    align-self: start;
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
    padding-left: 16px;
  }

  .page-about .ab-chapter__rail::after {
    content: "";
    display: block;
    width: 1px;
    height: clamp(56px, 11vh, 150px);
    margin-top: 4px;
    background: linear-gradient(180deg, var(--warm-gold), rgba(36, 56, 74, 0));
  }
}

@media (min-width: 980px) {
  .page-about .ab-split {
    grid-template-columns: minmax(0, 1fr) minmax(0, 320px);
    align-items: start;
    gap: clamp(24px, 3.4vw, 52px);
  }

  .page-about .ab-figure--team {
    position: sticky;
    top: var(--ab-rail-top);
  }
}

@media (min-width: 1000px) {
  .page-about .ab-stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 30px 40px;
  }
}

@media (max-width: 460px) {
  .page-about .ab-node {
    grid-template-columns: minmax(0, 1fr);
    gap: 6px;
  }

  .page-about .ab-node__year {
    font-size: var(--t17);
  }

  .page-about .ab-node.is-now .ab-node__year::after {
    display: inline;
    margin: 0 0 0 10px;
  }
}