/* ===== 品牌自述 / about ===== */
.page-about {
  --about-idx-w: 268px;
  --about-flow: clamp(32px, 5vw, 72px);
  --about-accent-glow: rgba(255, 106, 26, 0.18);
  background-color: var(--ink-900);
  color: var(--text-1);
}

/* ----- 首屏 ----- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  border-bottom: 1px solid var(--line);
  background-color: var(--ink-900);
  background-image:
    linear-gradient(to right, var(--line-soft) 1px, transparent 1px),
    linear-gradient(to bottom, var(--line-soft) 1px, transparent 1px);
  background-size: 64px 64px;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -20%;
  right: -14%;
  width: min(760px, 80vw);
  aspect-ratio: 1 / 1;
  background: radial-gradient(circle at center, var(--about-accent-glow), rgba(255, 106, 26, 0) 62%);
  pointer-events: none;
}

.page-about .about-hero__grid {
  position: relative;
  z-index: 1;
  display: grid;
  gap: clamp(28px, 4vw, 48px);
  padding-block: clamp(30px, 5vw, 68px) clamp(34px, 5vw, 76px);
}

.page-about .about-hero__copy {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.page-about .breadcrumb {
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--text-3);
}

.page-about .breadcrumb a {
  color: var(--text-2);
  text-decoration: none;
}

.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus-visible {
  color: var(--orange);
}

.page-about .about-hero__eyebrow {
  margin: 0;
  color: var(--orange);
}

.page-about .about-hero__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(34px, 7vw, 68px);
  line-height: 1.04;
  letter-spacing: -0.02em;
  max-width: 15em;
}

.page-about .about-hero__lede {
  margin: 0;
  max-width: 40em;
  color: var(--text-2);
  font-size: clamp(15px, 1.6vw, 18px);
  line-height: 1.8;
}

.page-about .about-hero__facts {
  list-style: none;
  margin: 8px 0 0;
  padding: 20px 0 0;
  border-top: 1px solid var(--line);
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 18px 24px;
}

.page-about .about-hero__facts li {
  display: flex;
  flex-direction: column;
  gap: 6px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--text-3);
}

.page-about .about-hero__fnum {
  font-family: var(--font-num);
  font-size: clamp(26px, 3.4vw, 40px);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--orange);
}

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

.page-about .about-hero__visual img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border: 1px solid var(--line);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 30px), calc(100% - 30px) 100%, 0 100%);
}

.page-about .about-hero__visual figcaption {
  margin-top: 12px;
  padding-left: 10px;
  border-left: 2px solid var(--orange);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--text-3);
}

/* ----- 主体两栏 ----- */
.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 4vw, 44px);
  padding-block: var(--about-flow);
  align-items: start;
}

/* ----- 章节索引 ----- */
.page-about .about-index {
  min-width: 0;
}

.page-about .about-index__label {
  margin: 0 0 12px;
  color: var(--text-3);
}

.page-about .about-index__list {
  list-style: none;
  margin: 0;
  padding: 0 0 4px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
}

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

.page-about .about-index__link {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 9px 14px;
  border: 1px solid var(--line);
  background-color: var(--ink-850);
  color: var(--text-2);
  text-decoration: none;
  font-size: 13px;
  white-space: nowrap;
  transition: color 0.18s var(--ease-out), border-color 0.18s var(--ease-out), background-color 0.18s var(--ease-out);
}

.page-about .about-index__link:hover,
.page-about .about-index__link:focus-visible {
  color: var(--paper);
  border-color: var(--orange);
  background-color: var(--ink-800);
}

.page-about .about-index__n {
  font-family: var(--font-num);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--orange);
}

/* ----- 正文流 ----- */
.page-about .about-flow {
  min-width: 0;
  display: flex;
  flex-direction: column;
}

.page-about .about-sec {
  padding-block: clamp(30px, 4.5vw, 52px);
  border-top: 1px solid var(--line);
  scroll-margin-top: 80px;
}

.page-about .about-sec:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .about-sec__head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  align-items: baseline;
  gap: clamp(12px, 2vw, 22px);
  margin-bottom: clamp(14px, 2vw, 22px);
}

.page-about .about-sec__num {
  font-family: var(--font-num);
  font-size: clamp(26px, 3.2vw, 40px);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--orange);
}

.page-about .about-sec__text {
  max-width: 40em;
  color: var(--text-2);
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.85;
}

.page-about .about-sec__text p {
  margin: 0 0 14px;
}

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

.page-about .about-sec__text a,
.page-about .about-note a {
  color: var(--orange-soft);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ----- 要点列表 ----- */
.page-about .about-pull {
  list-style: none;
  margin: clamp(18px, 2.6vw, 28px) 0 0;
  padding: 0;
  max-width: 42em;
  display: grid;
  gap: 12px;
}

.page-about .about-pull li {
  position: relative;
  padding-left: 20px;
  font-size: 14px;
  line-height: 1.75;
  color: var(--text-2);
}

.page-about .about-pull li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 10px;
  height: 2px;
  background-color: var(--orange);
}

/* ----- 工序步骤 ----- */
.page-about .about-steps {
  list-style: none;
  margin: clamp(18px, 2.6vw, 28px) 0 0;
  padding: 0;
  max-width: 46em;
}

.page-about .about-step {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 14px;
  padding: 16px 0;
  border-top: 1px solid var(--line);
}

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

.page-about .about-step__n {
  padding-top: 4px;
  font-family: var(--font-num);
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--orange);
}

.page-about .about-step__body h3 {
  margin: 0 0 6px;
}

.page-about .about-step__body p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--text-2);
}

/* ----- 配图 ----- */
.page-about .about-shot,
.page-about .about-plate {
  margin: clamp(22px, 3vw, 34px) 0 0;
}

.page-about .about-shot img,
.page-about .about-plate img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border: 1px solid var(--line);
}

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

.page-about .about-plate img {
  aspect-ratio: 4 / 3;
  opacity: 0.55;
}

.page-about .about-shot figcaption,
.page-about .about-plate figcaption {
  margin-top: 10px;
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--text-3);
}

/* ----- 旁注 ----- */
.page-about .about-note {
  max-width: 40em;
  margin: clamp(18px, 2.4vw, 26px) 0 0;
  padding: 14px 16px;
  background-color: var(--ink-850);
  border-left: 2px solid var(--orange);
  font-size: 14px;
  line-height: 1.8;
  color: var(--text-2);
}

/* ----- 结构图 ----- */
.page-about .about-map {
  margin: clamp(22px, 3vw, 34px) 0 0;
  padding: clamp(14px, 2.4vw, 28px);
  border: 1px solid var(--line);
  background-color: var(--ink-850);
}

.page-about .about-map__svg {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
}

.page-about .about-map__links path {
  fill: none;
  stroke: var(--line);
  stroke-width: 1.5;
}

.page-about .about-map__node rect {
  fill: var(--ink-800);
  stroke: var(--line);
  stroke-width: 1.5;
  transition: stroke 0.18s var(--ease-out), fill 0.18s var(--ease-out);
}

.page-about .about-map__node:hover rect,
.page-about .about-map__node:focus-within rect {
  stroke: var(--orange);
  fill: #1D2127;
}

.page-about .about-map__node text {
  font-family: var(--font-sans);
  font-size: 21px;
  fill: var(--text-1);
  dominant-baseline: middle;
}

.page-about .about-map__node--aux text {
  font-size: 19px;
  fill: var(--text-2);
}

.page-about .about-map figcaption {
  margin-top: 14px;
  font-size: 12px;
  line-height: 1.7;
  letter-spacing: 0.04em;
  color: var(--text-3);
}

/* ----- 换设备对照 ----- */
.page-about .about-devices {
  max-width: 46em;
  margin-top: clamp(18px, 2.6vw, 28px);
  display: grid;
  gap: 1px;
  border: 1px solid var(--line);
  background-color: var(--line);
}

.page-about .about-devices__col {
  padding: clamp(16px, 2.4vw, 24px);
  background-color: var(--ink-850);
}

.page-about .about-devices__col .t-label {
  margin: 0 0 12px;
  color: var(--orange);
}

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

.page-about .about-devices__col li {
  position: relative;
  padding-left: 16px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--text-2);
}

.page-about .about-devices__col li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.68em;
  width: 6px;
  height: 6px;
  border: 1px solid var(--orange);
  transform: rotate(45deg);
}

/* ----- 团队分工 ----- */
.page-about .about-roles {
  margin-top: clamp(18px, 2.6vw, 28px);
  display: grid;
  gap: clamp(14px, 2vw, 20px);
  grid-template-columns: repeat(auto-fit, minmax(210px, 1fr));
}

.page-about .about-role {
  padding: clamp(16px, 2.2vw, 24px);
  background-color: var(--paper);
  color: var(--ink-text);
  border: 1px solid #D9D2C6;
  box-shadow: 6px 6px 0 rgba(255, 106, 26, 0.16);
}

.page-about .about-role__metric {
  margin: 0 0 8px;
  font-family: var(--font-num);
  font-size: clamp(30px, 4vw, 44px);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--orange);
}

.page-about .about-role__metric small {
  font-size: 0.45em;
  margin-left: 2px;
  color: #8A8378;
}

.page-about .about-role h3 {
  margin: 0 0 8px;
  color: var(--ink-text);
}

.page-about .about-role p:last-child {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: #4A5058;
}

/* ----- 发展历程 ----- */
.page-about .about-timeline {
  list-style: none;
  margin: clamp(20px, 3vw, 32px) 0 0;
  padding: 0 0 10px;
  display: grid;
  grid-auto-flow: column;
  grid-auto-columns: minmax(230px, 1fr);
  gap: clamp(14px, 2vw, 22px);
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .about-timeline__item {
  position: relative;
  padding-top: 26px;
  border-top: 1px solid var(--line);
}

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  top: -4px;
  left: 0;
  width: 8px;
  height: 8px;
  background-color: var(--orange);
  transform: rotate(45deg);
}

.page-about .about-timeline__stage {
  margin: 0 0 8px;
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--text-3);
}

.page-about .about-timeline__item h3 {
  margin: 0 0 8px;
}

.page-about .about-timeline__item p {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--text-2);
}

/* ----- 下一步 ----- */
.page-about .about-next {
  margin-top: clamp(36px, 5vw, 60px);
  padding: clamp(24px, 3.4vw, 40px);
  border: 1px solid var(--line);
  background-image:
    linear-gradient(135deg, rgba(255, 106, 26, 0.14), rgba(255, 106, 26, 0) 62%);
  background-color: var(--ink-850);
  display: grid;
  gap: 16px;
}

.page-about .about-next h2 {
  margin: 0;
}

.page-about .about-next p {
  margin: 0;
  max-width: 44em;
  font-size: 15px;
  line-height: 1.8;
  color: var(--text-2);
}

.page-about .about-next__links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 4px;
}

/* ----- 中等宽度 ----- */
@media (min-width: 48em) {
  .page-about .about-devices {
    grid-template-columns: 1fr 1fr;
  }
}

/* ----- 桌面：轨道索引 + 分段正文 ----- */
@media (min-width: 62em) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    align-items: center;
    gap: clamp(36px, 5vw, 72px);
  }

  .page-about .about-body {
    grid-template-columns: var(--about-idx-w) minmax(0, 1fr);
    gap: clamp(40px, 6vw, 96px);
  }

  .page-about .about-index {
    position: sticky;
    top: 32px;
    border-left: 1px solid var(--line);
  }

  .page-about .about-index__label {
    padding-left: 14px;
  }

  .page-about .about-index__list {
    display: block;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .about-index__link {
    display: flex;
    width: 100%;
    align-items: flex-start;
    margin-left: -1px;
    padding: 10px 0 10px 14px;
    border: 0;
    border-left: 2px solid transparent;
    background: none;
    white-space: normal;
    font-size: 14px;
    line-height: 1.5;
  }

  .page-about .about-index__link:hover,
  .page-about .about-index__link:focus-visible {
    background: none;
    color: var(--paper);
    border-left-color: var(--orange);
  }

  .page-about .about-timeline {
    grid-auto-columns: minmax(200px, 1fr);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-index__link,
  .page-about .about-map__node rect {
    transition: none;
  }
}