.page-about {
  --about-line: rgba(169, 159, 173, 0.18);
  --about-gold-soft: rgba(201, 162, 61, 0.14);
  --about-neon-soft: rgba(155, 77, 255, 0.16);
  background: var(--midnight);
  color: var(--smoke);
  overflow-x: clip;
}

.page-about .container {
  max-width: var(--container-w);
}

/* ===== Hero 区域 ===== */
.page-about .about-hero {
  position: relative;
  min-height: calc(100svh - 64px);
  padding: 132px 0 72px;
  overflow: hidden;
  isolation: isolate;
  display: flex;
  align-items: center;
}

.page-about .hero-media {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.page-about .hero-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.page-about .hero-media::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(11, 16, 38, 0.78) 0%, rgba(11, 16, 38, 0.58) 45%, rgba(30, 18, 64, 0.74) 100%);
}

.page-about .hero-rear-text {
  position: absolute;
  top: 12%;
  right: -2%;
  z-index: 0;
  font-family: var(--font-serif);
  font-weight: 900;
  font-size: 22vw;
  line-height: 1;
  color: transparent;
  -webkit-text-stroke: 1px rgba(201, 162, 61, 0.18);
  white-space: nowrap;
  pointer-events: none;
  user-select: none;
}

.page-about .hero-inner {
  position: relative;
  z-index: 2;
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.page-about .hero-breadcrumb {
  margin-bottom: 32px;
  font-family: var(--font-mono);
  font-size: 13px;
}

.page-about .hero-breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .hero-breadcrumb a {
  color: var(--mist);
  text-decoration: none;
  transition: color 0.3s var(--ease);
}

.page-about .hero-breadcrumb a:hover {
  color: var(--cyan);
}

.page-about .hero-breadcrumb li + li::before {
  content: "///";
  color: var(--gold);
  margin: 0 10px;
}

.page-about .hero-breadcrumb .is-active {
  color: var(--cyan);
}

.page-about .hero-kicker {
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--gold);
  font-family: var(--font-mono);
  font-size: 14px;
  letter-spacing: 0.12em;
  margin: 0 0 18px;
}

.page-about .hero-kicker::before {
  content: "";
  width: 48px;
  height: 1px;
  background: var(--gold);
}

.page-about .hero-title {
  font-family: var(--font-serif);
  font-weight: 900;
  font-size: clamp(2.1rem, 5vw, 3.5rem);
  line-height: 1.15;
  letter-spacing: -0.02em;
  max-width: 13em;
  margin: 0 0 20px;
  text-wrap: balance;
}

.page-about .hero-description {
  font-size: 16px;
  line-height: 1.75;
  color: rgba(242, 237, 233, 0.86);
  max-width: 720px;
  margin: 0 0 44px;
}

.page-about .hero-stats {
  width: 100%;
  max-width: 860px;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  border-top: 1px solid rgba(201, 162, 61, 0.4);
}

.page-about .hero-stat {
  padding: 22px 20px 20px 0;
  border-bottom: 1px solid rgba(201, 162, 61, 0.18);
}

.page-about .hero-stat:nth-child(even) {
  padding-left: 20px;
  padding-right: 0;
}

.page-about .stat-num {
  display: block;
  font-family: var(--font-serif);
  font-weight: 900;
  line-height: 1;
  font-size: clamp(2.4rem, 6vw, 3.4rem);
  color: var(--gold);
}

.page-about .stat-num sup {
  font-size: 0.5em;
  color: var(--cyan);
}

.page-about .stat-label {
  display: block;
  font-size: 13px;
  color: var(--mist);
  margin-top: 10px;
  letter-spacing: 0.03em;
}

/* ===== 章节目录 Sticky ===== */
.page-about .about-chapters {
  position: sticky;
  top: 64px;
  z-index: 35;
  background: rgba(11, 16, 38, 0.85);
  backdrop-filter: blur(10px);
  border-block: 1px solid var(--about-line);
  overflow: hidden;
}

.page-about .about-chapters::before {
  content: "";
  display: block;
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, var(--neon), var(--cyan));
  transform: scaleX(1);
}

@supports (animation-timeline: scroll()) {
  .page-about .about-chapters::before {
    transform-origin: 0 50%;
    animation-name: about-progress;
    animation-timing-function: linear;
    animation-fill-mode: both;
    animation-timeline: scroll(root);
  }
}

@keyframes about-progress {
  from { transform: scaleX(0); }
  to { transform: scaleX(1); }
}

.page-about .about-chapters-list {
  list-style: none;
  margin: 0;
  padding: 16px 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px 32px;
}

.page-about .about-chapters-list a {
  color: var(--mist);
  text-decoration: none;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.06em;
  transition: color 0.3s var(--ease);
}

.page-about .about-chapters-list a::before {
  content: "//";
  color: var(--gold);
  margin-right: 8px;
}

.page-about .about-chapters-list a:hover {
  color: var(--cyan);
}

/* ===== 章节基础 ===== */
.page-about .about-section {
  position: relative;
  padding: 104px 0;
}

.page-about .about-section .container {
  position: relative;
  z-index: 1;
}

.page-about .section-heading {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 4px;
  margin-bottom: 56px;
}

.page-about .arch-num {
  display: block;
  font-family: var(--font-serif);
  font-weight: 900;
  font-size: clamp(4rem, 12vw, 7rem);
  line-height: 0.95;
  color: transparent;
  -webkit-text-stroke: 1px rgba(201, 162, 61, 0.6);
  margin-bottom: 12px;
}

.page-about .section-kicker {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.14em;
  color: var(--neon);
  margin: 0 0 8px;
}

.page-about .section-title {
  font-family: var(--font-serif);
  font-weight: 900;
  font-size: clamp(1.6rem, 4vw, 2.4rem);
  letter-spacing: -0.01em;
  color: var(--smoke);
  margin: 0;
}

/* ===== 品牌使命 ===== */
.page-about .mission-section {
  background: linear-gradient(180deg, rgba(11, 16, 38, 0.4), rgba(30, 18, 64, 0.32));
}

.page-about .mission-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 48px;
}

.page-about .mission-copy p {
  font-size: 15px;
  line-height: 1.85;
  margin: 0 0 16px;
  color: rgba(242, 237, 233, 0.84);
}

.page-about .mission-lead {
  font-size: 20px;
  line-height: 1.7;
  color: var(--smoke);
  font-weight: 500;
  margin-bottom: 24px;
}

.page-about .mission-copy .btn {
  margin-top: 12px;
}

.page-about .mission-panel {
  background: linear-gradient(160deg, rgba(30, 18, 64, 0.85), rgba(11, 16, 38, 0.92));
  border: 1px solid rgba(201, 162, 61, 0.28);
  padding: 32px 28px;
  position: relative;
}

.page-about .mission-panel::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 3px;
  height: 100%;
  background: var(--gold);
}

.page-about .panel-label {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--cyan);
}

.page-about .mission-facts {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
}

.page-about .mission-facts li {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 16px;
  padding: 14px 0;
  border-top: 1px solid var(--about-line);
  font-size: 14px;
  color: var(--mist);
}

.page-about .mission-facts strong {
  font-family: var(--font-serif);
  font-size: 28px;
  color: var(--gold);
}

/* ===== 索引编年史 ===== */
.page-about .chronology-section {
  background: radial-gradient(circle at 80% 20%, rgba(155, 77, 255, 0.08), transparent 42%);
}

.page-about .timeline {
  position: relative;
  margin-top: 64px;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: 18px;
  width: 2px;
  background: linear-gradient(180deg, var(--neon), var(--gold), var(--cyan));
  opacity: 0.5;
}

.page-about .tl-item {
  position: relative;
  padding-left: 60px;
  margin-bottom: 68px;
}

.page-about .tl-node {
  position: absolute;
  left: 0;
  top: 0;
  width: 38px;
  height: 38px;
  border-radius: 50%;
  background: var(--midnight);
  border: 2px solid var(--gold);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 0 20px rgba(155, 77, 255, 0.35);
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--gold);
  z-index: 3;
  cursor: default;
}

.page-about .tl-node::after {
  content: "";
  position: absolute;
  inset: -8px;
  border-radius: 50%;
  border: 1px dashed rgba(201, 162, 61, 0.4);
}

.page-about .tl-v1 .tl-node {
  border-color: var(--gold);
}

.page-about .tl-v2 .tl-node {
  border-color: var(--neon);
  color: var(--neon);
}

.page-about .tl-v3 .tl-node {
  border-color: var(--cyan);
  color: var(--cyan);
}

.page-about .tl-now .tl-node {
  border-color: var(--gold);
  background: rgba(201, 162, 61, 0.12);
}

.page-about .tl-hint {
  position: absolute;
  left: 50%;
  top: calc(100% + 12px);
  transform: translateX(-30%);
  background: var(--abyss);
  border: 1px solid rgba(201, 162, 61, 0.5);
  color: var(--smoke);
  font-family: var(--font-sans);
  font-size: 12px;
  padding: 6px 10px;
  white-space: nowrap;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s var(--ease), transform 0.3s var(--ease), visibility 0.3s;
  pointer-events: none;
  z-index: 9;
}

.page-about .tl-node:hover .tl-hint,
.page-about .tl-node:focus-visible .tl-hint {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%);
}

.page-about .tl-card {
  position: relative;
  background: linear-gradient(180deg, rgba(30, 18, 64, 0.55), rgba(11, 16, 38, 0.9));
  border: 1px solid rgba(169, 159, 173, 0.16);
  border-left: 2px solid var(--neon);
  padding: 28px 26px 30px;
  transition: transform 0.4s var(--ease), box-shadow 0.4s var(--ease), border-color 0.4s var(--ease);
}

.page-about .tl-card:hover {
  border-left-color: var(--cyan);
  box-shadow: 0 16px 50px rgba(155, 77, 255, 0.18);
  transform: translateY(-2px);
}

.page-about .tl-card-head {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 14px;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: 16px;
}

.page-about .tl-era {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--cyan);
  background: rgba(0, 229, 255, 0.07);
  border: 1px solid rgba(0, 229, 255, 0.25);
  padding: 4px 10px;
}

.page-about .tl-period {
  font-size: 14px;
  font-weight: 600;
  color: var(--gold);
}

.page-about .tl-card p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: rgba(242, 237, 233, 0.84);
}

.page-about .tl-img {
  margin-top: 20px;
  width: 100%;
  height: auto;
  border: 1px solid rgba(201, 162, 61, 0.25);
}

@supports (animation-timeline: view()) {
  @media (prefers-reduced-motion: no-preference) {
    .page-about .tl-card {
      animation-name: about-card-floating;
      animation-timing-function: linear;
      animation-fill-mode: both;
      animation-timeline: view(block 82% auto);
    }
    .page-about .tl-left .tl-card {
      animation-name: about-card-left;
    }
    .page-about .tl-right .tl-card {
      animation-name: about-card-right;
    }
  }
}

@keyframes about-card-floating {
  from { opacity: 0.3; transform: translateY(34px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes about-card-left {
  from { opacity: 0.3; transform: translateX(-28px); }
  to { opacity: 1; transform: translateX(0); }
}

@keyframes about-card-right {
  from { opacity: 0.3; transform: translateX(28px); }
  to { opacity: 1; transform: translateX(0); }
}

/* ===== 编辑与审核准则 ===== */
.page-about .editorial-section {
  background: linear-gradient(180deg, rgba(30, 18, 64, 0.24), rgba(11, 16, 38, 0.6));
}

.page-about .editorial-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
}

.page-about .ed-card {
  position: relative;
  padding: 34px 30px 30px;
  background: linear-gradient(180deg, rgba(11, 16, 38, 0.68), rgba(30, 18, 64, 0.55));
  border: 1px solid rgba(169, 159, 173, 0.16);
  overflow: hidden;
  transition: border-color 0.4s var(--ease), box-shadow 0.4s var(--ease);
}

.page-about .ed-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: linear-gradient(90deg, var(--neon), var(--gold));
  transform: scaleX(0.6);
  transform-origin: 0 50%;
  transition: transform 0.5s var(--ease);
}

.page-about .ed-card:hover::before {
  transform: scaleX(1);
}

.page-about .ed-card:hover {
  border-color: rgba(201, 162, 61, 0.35);
  box-shadow: 0 20px 54px rgba(155, 77, 255, 0.13);
}

.page-about .ed-card-index {
  display: block;
  font-family: var(--font-serif);
  font-weight: 900;
  font-size: clamp(3rem, 7vw, 4.5rem);
  line-height: 1;
  color: transparent;
  -webkit-text-stroke: 1px rgba(201, 162, 61, 0.55);
  margin-bottom: 20px;
}

.page-about .ed-card h3 {
  margin: 0 0 12px;
  font-size: 19px;
  font-weight: 700;
  color: var(--smoke);
}

.page-about .ed-card p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: rgba(242, 237, 233, 0.76);
}

/* ===== 技术架构 ===== */
.page-about .arch-section {
  background: radial-gradient(circle at 15% 80%, rgba(155, 77, 255, 0.1), transparent 40%);
}

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

.page-about .arch-copy p {
  margin: 0 0 20px;
  font-size: 15px;
  line-height: 1.85;
  color: rgba(242, 237, 233, 0.84);
}

.page-about .arch-list {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  border-top: 1px solid var(--about-line);
}

.page-about .arch-list li {
  display: flex;
  gap: 14px;
  padding: 16px 0;
  border-bottom: 1px solid var(--about-line);
  font-size: 14.5px;
  line-height: 1.7;
  color: rgba(242, 237, 233, 0.82);
}

.page-about .arch-list li::before {
  content: "→";
  font-family: var(--font-mono);
  color: var(--neon);
  flex: none;
}

.page-about .arch-list strong {
  color: var(--gold);
  font-weight: 600;
}

.page-about .arch-visual {
  width: 100%;
  height: auto;
  border: 1px solid rgba(155, 77, 255, 0.32);
  box-shadow: var(--shadow-card);
}

/* ===== 底部承接区 ===== */
.page-about .outro-section {
  padding: 104px 0 112px;
  border-top: 1px solid var(--about-line);
}

.page-about .outro-kicker {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.14em;
  color: var(--cyan);
  margin: 0 0 28px;
}

.page-about .outro-row {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
}

.page-about .outro-card {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 30px 26px;
  background: linear-gradient(180deg, rgba(30, 18, 64, 0.8), rgba(11, 16, 38, 0.9));
  border: 1px solid rgba(169, 159, 173, 0.18);
  text-decoration: none;
  transition: border-color 0.4s var(--ease), transform 0.4s var(--ease), box-shadow 0.4s var(--ease);
  position: relative;
}

.page-about .outro-card:hover {
  border-color: var(--gold);
  transform: translateY(-4px);
  box-shadow: 0 20px 50px rgba(155, 77, 255, 0.14);
}

.page-about .outro-card-label {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--neon);
}

.page-about .outro-card-title {
  font-size: 17px;
  line-height: 1.55;
  color: var(--smoke);
  font-weight: 600;
}

/* ===== 平板与桌面断点 ===== */
@media (min-width: 700px) {
  .page-about .hero-stats {
    grid-template-columns: repeat(4, 1fr);
  }

  .page-about .hero-stat:nth-child(even) {
    padding-left: 20px;
  }
}

@media (min-width: 880px) {
  .page-about .timeline::before {
    left: 50%;
    transform: translateX(-1px);
  }

  .page-about .tl-item {
    width: 50%;
    padding-left: 0;
    margin-bottom: 80px;
  }

  .page-about .tl-left {
    padding-right: 56px;
  }

  .page-about .tl-right {
    margin-left: 50%;
    padding-left: 56px;
  }

  .page-about .tl-node {
    left: 50%;
    top: 6px;
    transform: translateX(-50%);
  }

  .page-about .tl-hint {
    left: 50%;
    top: calc(100% + 12px);
  }
}

@media (min-width: 900px) {
  .page-about .mission-grid {
    grid-template-columns: 1.2fr 0.8fr;
    gap: 72px;
    align-items: start;
  }

  .page-about .editorial-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .page-about .arch-wrap {
    grid-template-columns: 1.05fr 0.95fr;
    gap: 64px;
    align-items: center;
  }

  .page-about .outro-row {
    grid-template-columns: repeat(3, 1fr);
  }
}