.page-about {
  --about-rail: 212px;
  --about-item-pad: clamp(16px, 2.4vw, 26px);
  display: block;
  overflow-x: clip;
}

/* ============ 首屏 ============ */
.page-about .about-hero {
  padding: clamp(20px, 3.4vw, 42px) 0 clamp(44px, 6.4vw, 92px);
  border-bottom: 1px solid var(--grid);
  background:
    radial-gradient(1100px 520px at 78% -10%, rgba(0, 229, 255, 0.13), transparent 62%),
    radial-gradient(760px 420px at 6% 96%, rgba(255, 138, 61, 0.08), transparent 68%),
    linear-gradient(180deg, rgba(14, 32, 54, 0.72), rgba(10, 22, 40, 0) 74%);
}

.page-about .about-hero__inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(22px, 4vw, 52px);
}

@media (min-width: 1024px) {
  .page-about .about-hero__inner {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    align-items: start;
  }
}

/* 左侧品牌轨道（手册书脊） */
.page-about .about-spine {
  display: flex;
  flex-direction: column;
  gap: 14px;
  padding-left: 14px;
  border-left: 1px solid var(--grid);
}

@media (min-width: 1024px) {
  .page-about .about-spine {
    position: sticky;
    top: 132px;
  }
}

.page-about .about-spine__label {
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--teal);
  margin: 0;
}

.page-about .about-spine__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0 14px;
}

@media (min-width: 1024px) {
  .page-about .about-spine__list {
    grid-template-columns: minmax(0, 1fr);
  }
}

.page-about .about-spine__list a {
  display: flex;
  align-items: baseline;
  gap: 9px;
  padding: 8px 0;
  font-size: 13.5px;
  color: var(--muted);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.page-about .about-spine__list a .mono {
  font-size: 11px;
  color: var(--cyan);
  letter-spacing: 0.06em;
}

.page-about .about-spine__list a:hover,
.page-about .about-spine__list a:focus-visible {
  color: var(--text);
  border-bottom-color: var(--cyan);
  transform: translateX(3px);
}

.page-about .about-spine__meta {
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--grid);
  margin: 4px 0 0;
}

/* 首屏主区 */
.page-about .about-hero__main {
  display: grid;
  gap: clamp(16px, 2.4vw, 26px);
}

.page-about .about-hero__main h1 {
  margin: 0;
  font-family: var(--font-title);
  font-weight: 800;
  font-size: clamp(36px, 7.6vw, 74px);
  line-height: 1.03;
  letter-spacing: -0.01em;
  color: var(--text);
}

.page-about .about-hero__main .lead {
  margin: 0;
  max-width: 64ch;
  color: var(--muted);
  font-size: clamp(15px, 1.5vw, 17.5px);
  line-height: 1.85;
}

.page-about .about-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  background: var(--grid);
  border: 1px solid var(--grid);
  clip-path: var(--cut-md);
}

@media (min-width: 720px) {
  .page-about .about-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

.page-about .about-facts__item {
  background: var(--panel);
  padding: 14px 16px 16px;
  display: grid;
  gap: 6px;
  min-width: 0;
}

.page-about .about-facts dt {
  font-size: 11.5px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.page-about .about-facts dd {
  margin: 0;
  font-size: clamp(17px, 2vw, 22px);
  font-weight: 700;
  color: var(--cyan);
  line-height: 1.25;
}

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

/* ============ 章节通用 ============ */
.page-about .about-sec {
  padding: clamp(46px, 6.6vw, 100px) 0;
  border-bottom: 1px solid var(--grid);
}

.page-about .about-sec:last-of-type {
  border-bottom: 0;
}

.page-about .about-sec .section-head {
  margin-bottom: clamp(22px, 3.2vw, 42px);
}

/* ============ 01 起点与主张 ============ */
.page-about .about-origin {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(22px, 3.2vw, 46px);
}

@media (min-width: 900px) {
  .page-about .about-origin {
    grid-template-columns: minmax(0, 1.65fr) minmax(0, 1fr);
    align-items: start;
  }
}

.page-about .about-origin__body p {
  margin: 0 0 18px;
  max-width: 68ch;
  color: var(--muted);
  font-size: 16px;
  line-height: 1.88;
}

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

.page-about .about-origin__aside {
  border-left: 2px solid var(--amber);
  padding: 4px 0 4px 18px;
}

.page-about .about-aside__label {
  margin: 0 0 10px;
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--amber);
}

.page-about .about-aside__text {
  margin: 0;
  color: var(--text);
  font-size: 15.5px;
  line-height: 1.8;
  font-family: var(--font-title);
  font-weight: 500;
  letter-spacing: 0.01em;
}

/* ============ 02 时间线 ============ */
.page-about .about-sec--timeline {
  background:
    linear-gradient(180deg, rgba(20, 48, 79, 0.34), rgba(10, 22, 40, 0) 70%);
}

.page-about .about-tl {
  position: relative;
  padding: clamp(12px, 2vw, 22px) 0;
  background-image: repeating-linear-gradient(135deg, transparent 0 22px, rgba(31, 78, 107, 0.26) 22px 23px);
  -webkit-mask-image: radial-gradient(120% 96% at 50% 50%, #000 58%, transparent 100%);
  mask-image: radial-gradient(120% 96% at 50% 50%, #000 58%, transparent 100%);
}

.page-about .about-tl__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: clamp(14px, 2vw, 20px);
}

.page-about .about-tl__item {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
  padding: var(--about-item-pad);
  background: var(--panel);
  border: 1px solid var(--grid);
  clip-path: var(--cut-md);
  transition: transform var(--dur-slow) var(--ease), border-color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

@media (min-width: 780px) {
  .page-about .about-tl__item {
    grid-template-columns: 104px minmax(0, 1fr);
    gap: 20px;
    align-items: start;
  }

  .page-about .about-tl__item:nth-child(odd) {
    margin-right: clamp(0px, 6vw, 88px);
  }

  .page-about .about-tl__item:nth-child(even) {
    margin-left: clamp(0px, 6vw, 88px);
  }
}

.page-about .about-tl__item:hover,
.page-about .about-tl__item:focus-visible {
  transform: translateY(-3px);
  border-color: rgba(0, 229, 255, 0.6);
  background: var(--panel-2);
  outline: none;
}

.page-about .about-tl__item:focus-visible {
  box-shadow: inset 0 0 0 1px var(--cyan);
}

.page-about .about-tl__item--now {
  border-color: rgba(255, 138, 61, 0.5);
}

.page-about .about-tl__item--now:hover,
.page-about .about-tl__item--now:focus-visible {
  border-color: var(--amber);
}

.page-about .about-tl__item--now:focus-visible {
  box-shadow: inset 0 0 0 1px var(--amber);
}

.page-about .about-tl__year {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--cyan);
  white-space: nowrap;
}

.page-about .about-tl__year::before {
  content: "";
  width: 7px;
  height: 7px;
  flex: 0 0 auto;
  background: var(--cyan);
  clip-path: polygon(50% 0, 100% 50%, 50% 100%, 0 50%);
}

.page-about .about-tl__item--now .about-tl__year {
  color: var(--amber);
}

.page-about .about-tl__item--now .about-tl__year::before {
  background: var(--amber);
}

.page-about .about-tl__body h3 {
  margin: 0 0 8px;
  font-family: var(--font-title);
  font-weight: 700;
  font-size: clamp(19px, 2.3vw, 25px);
  letter-spacing: 0.01em;
  color: var(--text);
  line-height: 1.28;
}

.page-about .about-tl__body p {
  margin: 0;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.82;
}

.page-about .about-tl__body .about-tl__detail {
  margin-top: 12px;
  padding-left: 13px;
  border-left: 1px solid var(--grid);
  font-size: 13.5px;
  line-height: 1.78;
  color: rgba(159, 182, 201, 0.8);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-tl__item:hover .about-tl__detail,
.page-about .about-tl__item:focus-visible .about-tl__detail {
  color: var(--text);
  border-left-color: var(--cyan);
}

.page-about .about-plate {
  margin: clamp(28px, 4vw, 52px) 0 0;
  max-width: 760px;
}

@media (min-width: 900px) {
  .page-about .about-plate {
    margin-left: auto;
  }
}

.page-about .about-plate figcaption {
  margin-top: 12px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
  max-width: 52ch;
}

/* ============ 03 团队与研发 ============ */
.page-about .about-team {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 3.6vw, 52px);
}

@media (min-width: 940px) {
  .page-about .about-team {
    grid-template-columns: minmax(0, 1.3fr) minmax(0, 1fr);
    align-items: start;
  }
}

.page-about .about-team__body p {
  margin: 0 0 18px;
  max-width: 66ch;
  color: var(--muted);
  font-size: 16px;
  line-height: 1.88;
}

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

.page-about .about-team__meters {
  display: grid;
  gap: clamp(18px, 2.4vw, 26px);
  padding: clamp(18px, 2.6vw, 28px);
  background: var(--panel);
  border: 1px solid var(--grid);
  clip-path: var(--cut-lg);
}

.page-about .about-meter {
  display: grid;
  gap: 8px;
}

.page-about .about-meter__label {
  margin: 0;
  font-size: 11.5px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.page-about .about-meter__value {
  margin: 0;
  font-size: clamp(26px, 3.4vw, 36px);
  font-weight: 700;
  color: var(--cyan);
  line-height: 1.1;
}

.page-about .about-meter__track {
  display: block;
  height: 3px;
  width: 100%;
  background: rgba(31, 78, 107, 0.55);
  overflow: hidden;
}

.page-about .about-meter__fill {
  display: block;
  height: 100%;
  background: linear-gradient(90deg, var(--teal), var(--cyan));
}

.page-about .about-meter__fill--amber {
  background: linear-gradient(90deg, var(--teal), var(--amber));
}

.page-about .about-cadence {
  list-style: none;
  margin: 0;
  padding: 14px 0 0;
  border-top: 1px solid var(--grid);
  display: grid;
  gap: 10px;
}

.page-about .about-cadence li {
  display: grid;
  grid-template-columns: 74px minmax(0, 1fr);
  gap: 12px;
  align-items: baseline;
  font-size: 14px;
  color: var(--muted);
}

.page-about .about-cadence .mono {
  font-size: 12px;
  color: var(--cyan);
  letter-spacing: 0.06em;
}

/* ============ 04 适配协作生态 ============ */
.page-about .about-eco {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 3.4vw, 48px);
  align-items: start;
}

@media (min-width: 940px) {
  .page-about .about-eco {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  }
}

.page-about .about-flow {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--grid);
  border: 1px solid var(--grid);
  clip-path: var(--cut-lg);
}

.page-about .about-flow__step {
  position: relative;
  background: var(--panel);
  padding: clamp(16px, 2.2vw, 24px) clamp(16px, 2.2vw, 26px) clamp(16px, 2.2vw, 24px) clamp(46px, 4vw, 62px);
  transition: background-color var(--dur) var(--ease);
}

.page-about .about-flow__step:hover {
  background: var(--panel-2);
}

.page-about .about-flow__idx {
  position: absolute;
  left: clamp(16px, 2.2vw, 24px);
  top: clamp(18px, 2.4vw, 26px);
  font-size: 13px;
  letter-spacing: 0.12em;
  color: var(--amber);
}

.page-about .about-flow__step h3 {
  margin: 0 0 7px;
  font-family: var(--font-title);
  font-weight: 700;
  font-size: 20px;
  letter-spacing: 0.01em;
  color: var(--text);
}

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

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

.page-about .about-eco__counts {
  list-style: none;
  margin: clamp(26px, 3.6vw, 48px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  background: var(--grid);
  border: 1px solid var(--grid);
}

.page-about .about-eco__counts li {
  background: var(--ink-deep);
  padding: clamp(16px, 2.2vw, 24px) clamp(12px, 1.8vw, 22px);
  display: grid;
  gap: 6px;
  min-width: 0;
}

.page-about .about-eco__num {
  font-size: clamp(28px, 4.2vw, 44px);
  font-weight: 700;
  line-height: 1;
  color: var(--cyan);
}

.page-about .about-eco__unit {
  font-size: 13px;
  color: var(--muted);
  letter-spacing: 0.04em;
}

/* ============ 05 质量与认可 ============ */
.page-about .about-quality {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 3.6vw, 52px);
}

@media (min-width: 940px) {
  .page-about .about-quality {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.15fr);
    align-items: start;
  }
}

.page-about .about-honors {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: clamp(14px, 2vw, 20px);
}

.page-about .about-honors__item {
  padding: clamp(18px, 2.4vw, 26px);
  background: var(--panel);
  border: 1px solid var(--grid);
  border-left: 2px solid var(--amber);
  clip-path: var(--cut-md);
  transition: transform var(--dur-slow) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-honors__item:hover {
  transform: translateY(-2px);
  border-color: rgba(255, 138, 61, 0.65);
}

.page-about .about-honors__year {
  margin: 0 0 10px;
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--amber);
}

.page-about .about-honors__item h3 {
  margin: 0 0 9px;
  font-family: var(--font-title);
  font-weight: 700;
  font-size: clamp(19px, 2.2vw, 23px);
  color: var(--text);
  line-height: 1.3;
}

.page-about .about-honors__item p:last-child {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .about-rules {
  padding: clamp(20px, 2.8vw, 30px);
  border: 1px solid var(--grid);
  background:
    linear-gradient(160deg, rgba(0, 229, 255, 0.07), rgba(10, 22, 40, 0) 58%),
    var(--panel);
  clip-path: var(--cut-lg);
}

.page-about .about-rules__title {
  margin: 0 0 16px;
  font-family: var(--font-title);
  font-weight: 700;
  font-size: clamp(19px, 2.2vw, 23px);
  color: var(--text);
}

.page-about .about-rules__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .about-rules__list li {
  position: relative;
  padding-left: 20px;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .about-rules__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 8px;
  height: 1px;
  background: var(--cyan);
}

.page-about .about-rules__foot {
  margin: 18px 0 0;
  padding-top: 16px;
  border-top: 1px solid var(--grid);
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--muted);
}

/* ============ 06 服务地区 ============ */
.page-about .about-region {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 3.4vw, 48px);
  align-items: start;
}

@media (min-width: 900px) {
  .page-about .about-region {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
  }
}

.page-about .about-region__copy h2 {
  margin: 12px 0 16px;
  font-family: var(--font-title);
  font-weight: 800;
  font-size: clamp(28px, 4.4vw, 46px);
  line-height: 1.12;
  letter-spacing: -0.005em;
  color: var(--text);
}

.page-about .about-region__copy p {
  margin: 0 0 16px;
  max-width: 62ch;
  color: var(--muted);
  font-size: 16px;
  line-height: 1.88;
}

.page-about .about-region__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(20px, 2.6vw, 30px);
}

.page-about .about-region__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--grid);
  border: 1px solid var(--grid);
  clip-path: var(--cut-lg);
}

.page-about .about-region__list li {
  background: var(--panel);
  padding: clamp(15px, 2.2vw, 22px);
  display: grid;
  gap: 8px;
}

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

.page-about .about-region__val {
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--muted);
}

/* ============ 延伸入口 ============ */
.page-about .about-sec--next {
  padding-bottom: clamp(52px, 7vw, 104px);
}

.page-about .about-next__title {
  margin: 0 0 clamp(18px, 2.6vw, 30px);
  font-family: var(--font-title);
  font-weight: 700;
  font-size: clamp(20px, 2.6vw, 28px);
  letter-spacing: 0.02em;
  color: var(--text);
}

.page-about .about-next {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--grid);
  border: 1px solid var(--grid);
}

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

.page-about .about-next__item a {
  display: grid;
  gap: 8px;
  height: 100%;
  padding: clamp(18px, 2.4vw, 26px);
  background: var(--panel);
  text-decoration: none;
  transition: background-color var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.page-about .about-next__item a:hover,
.page-about .about-next__item a:focus-visible {
  background: var(--panel-2);
  transform: translateY(-2px);
}

.page-about .about-next__label {
  font-family: var(--font-title);
  font-weight: 700;
  font-size: 19px;
  letter-spacing: 0.02em;
  color: var(--text);
}

.page-about .about-next__item a:hover .about-next__label,
.page-about .about-next__item a:focus-visible .about-next__label {
  color: var(--cyan);
}

.page-about .about-next__desc {
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
}

@media (max-width: 420px) {
  .page-about .about-cadence li {
    grid-template-columns: minmax(0, 1fr);
    gap: 2px;
  }

  .page-about .about-eco__counts {
    grid-template-columns: minmax(0, 1fr);
  }
}
</main>