.page-about {
  --about-title-size: clamp(40px, 7vw, 88px);
  --about-rule: 3px solid var(--border-dark);
  --about-shadow-accent: 10px 10px 0 var(--purple);
  background: transparent;
  color: var(--ink);
}

/* ---------- Hero 标题区 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: 40px 0 80px;
  border-bottom: var(--about-rule);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: 0;
  right: 6vw;
  width: 220px;
  height: 220px;
  background: linear-gradient(135deg, var(--purple) 0%, transparent 70%);
  opacity: 0.18;
  clip-path: polygon(0 0, 100% 0, 100% 100%, 0 32%);
  pointer-events: none;
}

.page-about .about-hero__inner {
  max-width: calc(var(--content-max) - 160px);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

.page-about .about-hero .breadcrumb {
  margin-bottom: 64px;
}

.page-about .about-hero__idx {
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.18em;
  color: var(--ink-soft);
  margin-bottom: 28px;
}

.page-about .about-hero__idx::before {
  content: "";
  display: block;
  width: 36px;
  height: 10px;
  background: var(--purple);
  transform: skewX(-18deg);
  flex: none;
}

.page-about .about-hero h1 {
  font-size: var(--about-title-size);
  font-weight: 100;
  line-height: 1.05;
  letter-spacing: -0.02em;
  margin: 0 0 28px;
  max-width: 11em;
}

.page-about .about-hero__lead {
  font-size: clamp(16px, 2vw, 20px);
  line-height: 1.9;
  color: var(--ink-soft);
  max-width: 36em;
  margin: 0 0 48px;
}

.page-about .about-hero__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 40px;
  padding-top: 24px;
  border-top: 1px solid rgba(13, 13, 13, 0.25);
}

.page-about .about-hero__meta-item {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--ink);
}

.page-about .about-hero__meta-dot {
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--neon);
  box-shadow: 0 0 0 3px var(--paper), 0 0 0 4px var(--border-dark);
}

/* ---------- 章节基础 ---------- */
.page-about .about-section {
  padding: 72px 0;
}

.page-about .about-section + .about-section {
  border-top: 1px solid rgba(13, 13, 13, 0.12);
}

.page-about .about-overview {
  padding-top: 96px;
}

/* ---------- 01 品牌概述 ---------- */
.page-about .about-overview__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 48px;
  align-items: center;
}

.page-about .about-overview__content {
  position: relative;
  background: var(--paper-deep);
  border: var(--about-rule);
  box-shadow: var(--shadow-md);
  padding: clamp(32px, 5vw, 64px);
}

.page-about .about-overview__content::before {
  content: "01";
  position: absolute;
  top: -18px;
  left: 20px;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  background: var(--purple);
  color: #fff;
  border: 3px solid var(--border-dark);
  padding: 5px 12px;
  line-height: 1;
  letter-spacing: 0.1em;
}

.page-about .about-overview__label {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.14em;
  color: var(--ink-soft);
  text-transform: uppercase;
  margin-bottom: 18px;
}

.page-about .about-overview__text {
  font-size: 17px;
  line-height: 2;
  color: var(--ink);
  margin-bottom: 18px;
}

.page-about .about-overview__text:last-of-type {
  margin-bottom: 28px;
}

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

.page-about .about-overview__visual {
  display: grid;
  gap: 16px;
  margin: 0;
}

.page-about .about-overview__image {
  border: var(--about-rule);
  box-shadow: var(--about-shadow-accent);
  overflow: hidden;
}

.page-about .about-overview__image img {
  width: 100%;
  height: auto;
  display: block;
}

.page-about .about-overview__caption {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  font-size: 13px;
  color: var(--ink-soft);
}

/* ---------- 02 发展历程 ---------- */
.page-about .about-milestones__layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 48px;
}

.page-about .about-milestones__frame {
  border: var(--about-rule);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
  margin: 0;
}

.page-about .about-milestones__frame img {
  width: 100%;
  height: auto;
  display: block;
  transition: transform 0.6s var(--ease);
}

.page-about .about-milestones__frame:hover img {
  transform: scale(1.03);
}

.page-about .about-milestones__badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: 18px;
  font-family: var(--font-mono);
  font-size: 13px;
  background: var(--neon);
  border: var(--about-rule);
  padding: 6px 12px;
  transform: rotate(-2deg);
}

.page-about .about-milestones__list {
  display: grid;
  gap: 0;
}

.page-about .timeline-node {
  position: relative;
  padding: 0 0 52px 42px;
  border-left: 2px dashed rgba(13, 13, 13, 0.3);
}

.page-about .timeline-node:last-child {
  border-left-color: transparent;
  padding-bottom: 0;
}

.page-about .timeline-node__dot {
  position: absolute;
  left: -9px;
  top: 2px;
  width: 16px;
  height: 16px;
  background: var(--neon);
  border: 3px solid var(--border-dark);
  border-radius: 50%;
  box-shadow: 0 0 0 4px rgba(57, 255, 20, 0.15);
}

.page-about .timeline-node__year {
  font-family: var(--font-mono);
  font-size: 26px;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--purple);
  margin-bottom: 6px;
}

.page-about .timeline-node__body {
  padding: 20px 22px;
  border: 2px solid transparent;
  background: transparent;
  transition: background-color 0.4s var(--ease), border-color 0.4s var(--ease), transform 0.4s var(--ease);
}

.page-about .timeline-node:hover .timeline-node__body {
  background: var(--paper-deep);
  border-color: var(--border-dark);
  transform: translateX(6px);
}

.page-about .timeline-node__title {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: 10px;
}

.page-about .timeline-node__text {
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
}

/* ---------- 03 数据体系 ---------- */
.page-about .about-data__panel {
  position: relative;
  background: var(--blue);
  border: var(--about-rule);
  box-shadow: var(--shadow-md);
  padding: clamp(28px, 5vw, 72px);
  overflow: hidden;
}

.page-about .about-data__panel::before {
  content: "DATA SYSTEM";
  position: absolute;
  top: 22px;
  right: 22px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: rgba(255, 255, 255, 0.5);
  border: 1px solid rgba(255, 255, 255, 0.25);
  padding: 6px 12px;
  transform: rotate(2deg);
}

.page-about .about-data__panel::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 10px;
  background: var(--purple);
  clip-path: polygon(0 0, 100% 0, 100% 100%, 40% 100%);
  opacity: 0.7;
  pointer-events: none;
}

.page-about .about-data__head .section-head__idx {
  color: var(--neon);
  border-color: rgba(255, 255, 255, 0.4);
}

.page-about .about-data__head .section-head__title {
  color: #fff;
}

.page-about .about-data__head .section-head__sub {
  color: rgba(255, 255, 255, 0.55);
}

.page-about .about-data__stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px 24px;
  margin: 48px 0 56px;
}

.page-about .about-data__stat {
  border-top: 2px solid rgba(255, 255, 255, 0.22);
  padding-top: 18px;
}

.page-about .about-data__stat-value {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(36px, 6vw, 72px);
  font-weight: 700;
  line-height: 0.95;
  color: var(--neon);
  margin-bottom: 12px;
}

.page-about .about-data__stat-unit {
  font-size: 0.45em;
  color: rgba(255, 255, 255, 0.7);
  margin-left: 4px;
}

.page-about .about-data__stat-label {
  font-size: 14px;
  color: rgba(255, 255, 255, 0.72);
  letter-spacing: 0.06em;
}

.page-about .about-data__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 40px;
  margin-top: 40px;
}

.page-about .about-data__text {
  color: rgba(255, 255, 255, 0.85);
  font-size: 16px;
  line-height: 1.9;
}

.page-about .about-data__text p {
  margin-bottom: 18px;
}

.page-about .about-data__features {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.page-about .about-data__features li {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--neon);
  border: 1px solid rgba(57, 255, 20, 0.5);
  padding: 6px 12px;
  letter-spacing: 0.05em;
}

.page-about .about-data__arch {
  margin: 0;
  border: 2px solid rgba(255, 255, 255, 0.4);
  box-shadow: 8px 8px 0 rgba(0, 0, 0, 0.28);
  overflow: hidden;
  background: var(--paper-deep);
}

.page-about .about-data__arch img {
  width: 100%;
  height: auto;
  display: block;
}

.page-about .about-data__caption {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  padding: 14px 18px;
  font-size: 13px;
  color: var(--ink-soft);
  background: var(--paper);
  border-top: 2px solid var(--border-dark);
}

/* ---------- 04 服务承诺 ---------- */
.page-about .about-commit__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
}

.page-about .about-commit__item {
  position: relative;
  background: var(--paper);
  border: var(--about-rule);
  box-shadow: var(--shadow-sm);
  padding: clamp(28px, 4vw, 44px);
  overflow: hidden;
}

.page-about .about-commit__item:nth-child(2n) {
  box-shadow: var(--shadow-purple);
}

.page-about .about-commit__item::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 8px;
  background: var(--blue);
  clip-path: polygon(0 0, 100% 0, calc(100% - 56px) 100%, 0 100%);
}

.page-about .about-commit__item:nth-child(2)::before,
.page-about .about-commit__item:nth-child(4)::before {
  background: var(--purple);
}

.page-about .about-commit__idx {
  display: inline-block;
  font-size: 13px;
  letter-spacing: 0.12em;
  color: var(--ink-soft);
  margin-bottom: 20px;
}

.page-about .about-commit__item h3 {
  font-size: 24px;
  font-weight: 600;
  margin-bottom: 18px;
}

.page-about .about-commit__item p {
  font-size: 16px;
  line-height: 1.9;
  color: var(--ink-soft);
  margin-bottom: 24px;
}

.page-about .about-commit__item .btn {
  margin-top: 4px;
}

.page-about .about-commit__note {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  margin-top: 56px;
  padding: 20px 24px;
  background: var(--paper-deep);
  border-left: 6px solid var(--purple);
}

.page-about .about-commit__note-dot {
  flex: none;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--neon);
  border: 2px solid var(--border-dark);
  margin-top: 8px;
}

.page-about .about-commit__note p {
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
  margin: 0;
}

/* ---------- 桌面端布局 ---------- */
@media (min-width: 768px) {
  .page-about .about-overview__grid {
    grid-template-columns: 1.05fr 0.95fr;
    gap: 64px;
  }

  .page-about .about-data__stats {
    grid-template-columns: repeat(4, 1fr);
    gap: 40px;
  }

  .page-about .about-data__grid {
    grid-template-columns: 1fr 1fr;
    gap: 64px;
    align-items: center;
  }

  .page-about .about-commit__grid {
    grid-template-columns: 1fr 1fr;
    gap: 40px;
  }
}

@media (min-width: 940px) {
  .page-about .about-milestones__layout {
    display: grid;
    grid-template-columns: 0.72fr 1.28fr;
    gap: 72px;
    align-items: start;
  }

  .page-about .about-milestones__visual {
    position: sticky;
    top: 24px;
  }
}