/* ============ 品牌沿革 /story/ ============ */
.page-about {
  --about-idx: 172px;
  --about-gap: clamp(22px, 3vw, 46px);
  background: var(--paper);
  color: var(--ink-2);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  background: var(--ink);
  color: var(--paper);
  padding: clamp(22px, 4vw, 40px) 0 clamp(34px, 6vw, 68px);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -18%;
  right: -14%;
  width: min(620px, 64vw);
  height: 142%;
  background: var(--grad);
  clip-path: polygon(34% 0, 100% 0, 100% 100%, 0 100%);
  opacity: .52;
  z-index: -1;
  pointer-events: none;
}

.page-about .about-hero .breadcrumb__list {
  color: rgba(245, 240, 230, .68);
  font-size: 13px;
  letter-spacing: .05em;
}

.page-about .about-hero .breadcrumb__list a {
  color: var(--copper-lite);
  text-decoration: none;
}

.page-about .about-hero__kicker {
  margin: 16px 0 12px;
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--copper-lite);
}

.page-about .about-hero__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(30px, 5.4vw, 54px);
  line-height: 1.06;
  letter-spacing: .07em;
  color: #FFFFFF;
  max-width: 720px;
}

.page-about .about-hero__lede {
  margin: 16px 0 0;
  max-width: 62ch;
  font-size: clamp(15px, 1.7vw, 17px);
  line-height: 1.8;
  color: rgba(245, 240, 230, .86);
}

/* 日期栏 */
.page-about .date-rail {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px 14px;
  margin: clamp(24px, 3.4vw, 38px) 0 0;
  padding: 0;
}

.page-about .date-rail__item {
  padding: 6px 0 6px 12px;
  border-left: 2px solid var(--copper);
}

.page-about .date-rail__item dt {
  font-size: 12px;
  letter-spacing: .07em;
  color: var(--copper-lite);
}

.page-about .date-rail__item dd {
  margin: 4px 0 0;
  font-size: clamp(15px, 1.9vw, 19px);
  font-weight: 700;
  color: #FFFFFF;
}

/* ---------- 主体两栏 ---------- */
.page-about .about-body {
  margin-top: clamp(32px, 5vw, 62px);
  margin-bottom: clamp(48px, 7vw, 96px);
}

@media (min-width: 980px) {
  .page-about .about-body {
    display: grid;
    grid-template-columns: var(--about-idx) minmax(0, 1fr);
    gap: var(--about-gap);
    align-items: start;
  }
}

/* 年份索引 */
.page-about .year-index {
  margin: 0 0 clamp(26px, 4vw, 0);
}

@media (min-width: 980px) {
  .page-about .year-index {
    position: sticky;
    top: 24px;
    margin: 0;
  }
}

.page-about .year-index__title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: .18em;
  color: var(--ink-3);
}

.page-about .year-index__list {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0 0 6px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: thin;
}

@media (min-width: 980px) {
  .page-about .year-index__list {
    display: block;
    gap: 0;
    padding-bottom: 0;
    overflow: visible;
  }
}

.page-about .year-index__list a {
  display: flex;
  flex: 0 0 auto;
  flex-direction: column;
  gap: 2px;
  padding: 8px 12px;
  font-size: 13px;
  line-height: 1.5;
  letter-spacing: .04em;
  color: var(--ink-2);
  text-decoration: none;
  border-left: 2px solid var(--ink-3);
  white-space: nowrap;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}

@media (min-width: 980px) {
  .page-about .year-index__list a {
    white-space: normal;
  }
}

.page-about .year-index__list a .numeric {
  font-size: 12px;
  color: var(--ink-3);
  letter-spacing: .05em;
}

.page-about .year-index__list a:hover,
.page-about .year-index__list a:focus-visible {
  color: var(--copper);
  border-left-color: var(--copper);
  background: rgba(196, 107, 50, .08);
  outline: none;
}

.page-about .year-index__list a:focus-visible {
  box-shadow: inset 0 0 0 2px var(--copper-lite);
}

/* 内容流 */
.page-about .about-flow {
  min-width: 0;
}

.page-about .about-section {
  margin-bottom: clamp(46px, 7vw, 92px);
  scroll-margin-top: 26px;
}

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

.page-about .about-section__head {
  display: flex;
  align-items: baseline;
  gap: 14px;
  margin-bottom: clamp(18px, 2.4vw, 28px);
  padding-bottom: 10px;
  border-bottom: 1px solid var(--ink-3);
}

.page-about .about-section__num {
  flex: 0 0 auto;
  font-size: 13px;
  letter-spacing: .1em;
  color: var(--copper);
}

.page-about .about-section__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(20px, 2.7vw, 30px);
  line-height: 1.25;
  letter-spacing: .07em;
  color: var(--ink);
}

.page-about .about-section > p {
  margin: 0 0 1.2em;
  font-size: 16px;
  line-height: 1.78;
  color: var(--ink-2);
}

.page-about .about-section > p a {
  color: var(--copper);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
  transition: color var(--dur) var(--ease);
}

.page-about .about-section > p a:hover,
.page-about .about-section > p a:focus-visible {
  color: var(--copper-lite);
  outline: none;
}

.page-about .about-tail {
  margin-top: clamp(20px, 3vw, 30px) !important;
  padding-top: 16px;
  border-top: 1px dashed var(--ink-3);
  font-size: 15px !important;
  color: var(--ink-3) !important;
}

.page-about .about-figure {
  margin: 0 0 clamp(22px, 3.4vw, 34px);
}

/* ---------- 时间线 ---------- */
.page-about .era {
  margin-bottom: 10px;
  border-top: 1px solid var(--ink-3);
  border-radius: 0;
  scroll-margin-top: 26px;
  transition: background var(--dur) var(--ease);
}

.page-about .era[open] {
  background: linear-gradient(180deg, rgba(44, 76, 107, .08) 0%, rgba(196, 107, 50, .07) 100%);
  border-radius: var(--radius-card);
}

.page-about .era__summary {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px 14px;
  padding: 16px 14px;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-display);
  font-size: clamp(16px, 2vw, 21px);
  font-weight: 800;
  letter-spacing: .06em;
  color: var(--ink);
  transition: color var(--dur) var(--ease);
}

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

.page-about .era__summary::after {
  content: "＋";
  margin-left: auto;
  font-family: var(--font-body);
  font-size: 15px;
  font-weight: 700;
  color: var(--copper);
}

.page-about .era[open] .era__summary::after {
  content: "－";
}

.page-about .era__summary:hover {
  color: var(--copper);
}

.page-about .era__summary:focus-visible {
  outline: 2px solid var(--copper-lite);
  outline-offset: -2px;
}

.page-about .era__range {
  font-size: 13px;
  letter-spacing: .08em;
  color: var(--copper);
}

.page-about .timeline {
  margin: 0;
  padding: 4px 14px 20px 20px;
  list-style: none;
}

.page-about .tl-item {
  position: relative;
  padding: 0 0 24px 24px;
  margin-left: 4px;
  border-left: 2px solid var(--ink-3);
}

.page-about .tl-item:last-child {
  padding-bottom: 4px;
  border-left-color: transparent;
}

.page-about .tl-item::before {
  content: "";
  position: absolute;
  left: -7px;
  top: 6px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--paper-lite);
  border: 2px solid var(--copper);
}

.page-about .tl-item__year {
  margin: 0;
  font-size: clamp(18px, 2.3vw, 24px);
  font-weight: 700;
  letter-spacing: .02em;
  color: var(--ink);
}

.page-about .tl-item__title {
  margin: 5px 0 6px;
  font-size: 15px;
  font-weight: 700;
  letter-spacing: .03em;
  color: var(--ink-2);
}

.page-about .tl-item__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.72;
  color: var(--ink-3);
}

.page-about .line-tag {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  margin-top: 10px;
  padding: 4px 10px 4px 8px;
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--ink-3);
  background: rgba(44, 76, 107, .1);
  border-radius: var(--radius-tag);
}

.page-about .line-tag::before {
  content: "";
  width: 14px;
  height: 3px;
  border-radius: 2px;
  background: var(--ink-2);
}

.page-about .line-tag--warranty::before {
  background: var(--copper);
}

.page-about .line-tag--record::before {
  background: var(--verify);
}

.page-about .about-note {
  margin-top: clamp(22px, 3vw, 32px);
}

/* ---------- 四条产品线 ---------- */
.page-about .term {
  font-family: var(--font-num);
  font-style: normal;
  color: var(--copper);
  border-bottom: 1px dotted var(--copper);
  cursor: help;
  text-decoration: none;
}

.page-about .series-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  margin-bottom: clamp(20px, 3vw, 30px);
}

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

@media (min-width: 1040px) {
  .page-about .series-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 12px;
  }
}

.page-about .series-card {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 18px 16px 16px;
  background: var(--paper-lite);
  border: 1px solid rgba(44, 76, 107, .18);
  border-top: 4px solid var(--ink-3);
  border-radius: var(--radius-card);
  transition: transform var(--dur) var(--ease), box-shadow var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .series-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 24px rgba(15, 34, 51, .14);
}

.page-about .series-card:focus-visible {
  outline: none;
  transform: translateY(-2px);
  box-shadow: 0 0 0 2px var(--copper-lite), 0 10px 24px rgba(15, 34, 51, .16);
}

.page-about .series-card--tide { border-top-color: var(--ink-2); }
.page-about .series-card--tide .series-card__mark { color: var(--ink-2); }
.page-about .series-card--wheel { border-top-color: var(--copper); }
.page-about .series-card--wheel .series-card__mark { color: var(--copper); }
.page-about .series-card--stove { border-top-color: var(--copper-lite); }
.page-about .series-card--stove .series-card__mark { color: var(--copper-lite); }
.page-about .series-card--air { border-top-color: var(--ink-3); }
.page-about .series-card--air .series-card__mark { color: var(--ink-3); }

.page-about .series-card__mark {
  display: block;
  width: 40px;
  height: 40px;
}

.page-about .series-card__name {
  margin: 0;
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 800;
  letter-spacing: .06em;
  color: var(--ink);
}

.page-about .series-card__meta {
  margin: 0;
  display: grid;
  gap: 6px;
}

.page-about .series-card__meta > div {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 10px;
  padding-bottom: 5px;
  border-bottom: 1px solid rgba(44, 76, 107, .16);
}

.page-about .series-card__meta dt {
  font-size: 12px;
  letter-spacing: .07em;
  color: var(--ink-3);
}

.page-about .series-card__meta dd {
  margin: 0;
  font-size: 14px;
  color: var(--ink);
}

.page-about .series-card__desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--ink-3);
}

/* ---------- 编辑制度 ---------- */
.page-about .cycle-list {
  display: grid;
  gap: 10px;
  margin: 0 0 clamp(20px, 3vw, 28px);
  padding: 0;
  list-style: none;
}

.page-about .cycle-list li {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 4px 18px;
  padding: 13px 16px;
  background: var(--paper-lite);
  border-left: 3px solid var(--ink-3);
  border-radius: var(--radius-tag);
}

.page-about .cycle-list__key {
  flex: 0 0 auto;
  min-width: 88px;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: .05em;
  color: var(--copper);
}

.page-about .cycle-list__val {
  flex: 1 1 220px;
  font-size: 15px;
  line-height: 1.72;
  color: var(--ink-2);
}

.page-about .table-scroll {
  margin: 0 0 clamp(20px, 3vw, 30px);
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.page-about .audit-table {
  width: 100%;
  min-width: 520px;
  border-collapse: collapse;
  background: var(--paper-lite);
  font-size: 14px;
}

.page-about .audit-table caption {
  padding-bottom: 10px;
  font-size: 13px;
  letter-spacing: .06em;
  color: var(--ink-3);
  text-align: left;
}

.page-about .audit-table th,
.page-about .audit-table td {
  padding: 11px 13px;
  text-align: left;
  border-bottom: 1px solid rgba(44, 76, 107, .16);
}

.page-about .audit-table thead th {
  background: var(--ink-2);
  color: var(--paper);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: .06em;
  white-space: nowrap;
}

.page-about .audit-table tbody td:first-child {
  font-weight: 700;
  color: var(--ink);
}

.page-about .audit-table tbody td {
  color: var(--ink-2);
  white-space: nowrap;
}

.page-about .audit-table tbody tr:last-child td {
  border-bottom: none;
}

/* ---------- 服务地区 ---------- */
.page-about .region-split {
  display: grid;
  gap: clamp(18px, 3vw, 30px);
  margin-bottom: clamp(24px, 3.4vw, 34px);
}

@media (min-width: 880px) {
  .page-about .region-split {
    grid-template-columns: minmax(0, 6fr) minmax(0, 5fr);
    align-items: start;
  }
}

.page-about .region-split .about-figure {
  margin: 0;
}

.page-about .region-split__body > p {
  margin: 0 0 1.1em;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--ink-2);
}

.page-about .region-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .region-stats li {
  padding: 10px 12px;
  background: var(--paper-lite);
  border-top: 3px solid var(--copper);
  border-radius: 0 0 var(--radius-tag) var(--radius-tag);
}

.page-about .region-stats__num {
  display: block;
  font-size: clamp(20px, 2.6vw, 26px);
  font-weight: 700;
  color: var(--ink);
  letter-spacing: .02em;
}

.page-about .region-stats__label {
  display: block;
  margin-top: 2px;
  font-size: 12px;
  letter-spacing: .07em;
  color: var(--ink-3);
}

.page-about .region-tier {
  display: grid;
  gap: 12px;
  margin: 0 0 clamp(18px, 2.6vw, 26px);
  padding: 0;
  list-style: none;
}

@media (min-width: 720px) {
  .page-about .region-tier {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

.page-about .region-tier__item {
  padding: 16px 16px 18px;
  background: linear-gradient(180deg, rgba(22, 52, 78, .9) 0%, rgba(15, 34, 51, .94) 100%);
  border-radius: var(--radius-card);
  color: var(--paper);
}

.page-about .region-tier__item:nth-child(2) {
  background: linear-gradient(180deg, rgba(44, 76, 107, .95) 0%, rgba(22, 52, 78, .96) 100%);
}

.page-about .region-tier__item:nth-child(3) {
  background: linear-gradient(180deg, rgba(44, 76, 107, .78) 0%, rgba(196, 107, 50, .55) 100%);
}

.page-about .region-tier__lv {
  display: inline-block;
  padding: 3px 9px;
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--copper-lite);
  border: 1px solid var(--copper);
  border-radius: var(--radius-tag);
}

.page-about .region-tier__title {
  margin: 12px 0 8px;
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 800;
  letter-spacing: .06em;
  color: #FFFFFF;
}

.page-about .region-tier__item p {
  margin: 0;
  font-size: 14px;
  line-height: 1.72;
  color: rgba(245, 240, 230, .82);
}

/* ---------- 词汇表 ---------- */
.page-about .glossary {
  margin: 0;
  padding: 0;
}

.page-about .glossary__row {
  display: grid;
  grid-template-columns: 1fr;
  gap: 5px;
  padding: 14px 0 14px 14px;
  border-bottom: 1px solid rgba(44, 76, 107, .16);
  border-left: 2px solid transparent;
  transition: background var(--dur) var(--ease), border-left-color var(--dur) var(--ease);
}

@media (min-width: 700px) {
  .page-about .glossary__row {
    grid-template-columns: 148px minmax(0, 1fr);
    gap: 0 22px;
  }
}

.page-about .glossary__row:hover,
.page-about .glossary__row:focus-within {
  background: rgba(196, 107, 50, .07);
  border-left-color: var(--copper);
}

.page-about .glossary dt {
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 800;
  letter-spacing: .08em;
  color: var(--ink);
  cursor: help;
}

.page-about .glossary dd {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.76;
  color: var(--ink-2);
}

/* ---------- 动效收敛 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .series-card,
  .page-about .year-index__list a,
  .page-about .glossary__row,
  .page-about .era {
    transition: none;
  }

  .page-about .series-card:hover,
  .page-about .series-card:focus-visible {
    transform: none;
  }
}
<<<END>>>