.page-about {
  --about-line: rgba(147, 168, 199, 0.16);
  position: relative;
}

/* ===== 页面头部 ===== */
.page-about .about-hero {
  position: relative;
  z-index: 0;
  padding: clamp(2.75rem, 5vw, 5rem) 0 clamp(2.5rem, 4vw, 3.5rem);
}

.page-about .about-hero::before {
  content: "IM";
  position: absolute;
  top: -0.35em;
  right: -0.08em;
  z-index: 0;
  font-family: var(--font-head);
  font-size: clamp(7rem, 18vw, 15rem);
  font-weight: 900;
  line-height: 1;
  letter-spacing: -0.04em;
  color: transparent;
  -webkit-text-stroke: 2px rgba(164, 75, 255, 0.15);
  pointer-events: none;
  user-select: none;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(to right, transparent, var(--c-purple), var(--c-cyan), transparent);
}

.page-about .about-hero > * {
  position: relative;
  z-index: 1;
}

.page-about .about-hero .breadcrumb {
  margin-bottom: 1.25rem;
}

.page-about .about-hero__meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.75rem;
  margin-top: 1.5rem;
}

.page-about .about-hero__title {
  margin: 0.1rem 0 0;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: clamp(2.1rem, 5.5vw, 4rem);
  line-height: 1.12;
  letter-spacing: 0.01em;
  max-width: 12em;
}

.page-about .about-hero__subtitle {
  margin: 0.55rem 0 1.35rem;
  font-family: var(--font-data);
  font-size: clamp(0.82rem, 1.6vw, 0.98rem);
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--c-green);
}

.page-about .about-hero__lead {
  max-width: 50em;
  margin: 0 0 1.85rem;
  font-size: clamp(1rem, 1.5vw, 1.14rem);
  line-height: 1.8;
}

.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.7rem;
  max-width: 820px;
}

.page-about .about-hero__stat {
  padding: 1rem 0.9rem;
  border-radius: 16px;
  background: linear-gradient(150deg, rgba(26, 35, 64, 0.72), rgba(11, 16, 38, 0.45));
  border: 1px solid var(--about-line);
  transition: transform 0.3s, border-color 0.3s;
}

.page-about .about-hero__stat:hover {
  transform: translateY(-2px);
  border-color: rgba(0, 229, 255, 0.35);
}

.page-about .about-hero__stat-num {
  display: block;
  font-family: var(--font-data);
  font-size: clamp(1.6rem, 2.4vw, 2rem);
  font-weight: 700;
  line-height: 1.05;
  color: var(--c-cyan);
}

.page-about .about-hero__stat-label {
  display: block;
  margin-top: 0.35rem;
  font-size: 0.82rem;
  line-height: 1.4;
  color: var(--c-text-dim);
}

/* ===== 主布局 ===== */
.page-about .about-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
  align-items: start;
}

/* ===== 章节导航 ===== */
.page-about .about-rail {
  position: sticky;
  top: calc(var(--header-h, 72px) + 0.85rem);
  z-index: 20;
  display: flex;
  align-items: center;
  gap: 0.25rem;
  overflow-x: auto;
  padding: 0.75rem;
  border-radius: 18px;
  background: rgba(11, 16, 38, 0.86);
  border: 1px solid var(--about-line);
  backdrop-filter: blur(14px);
  scrollbar-width: none;
}

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

.page-about .about-rail__label {
  flex: 0 0 auto;
  padding: 0.35rem 0.5rem;
  font-family: var(--font-data);
  font-size: 0.72rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--c-text-dim);
  white-space: nowrap;
}

.page-about .about-rail__item {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.55rem 0.75rem;
  border-radius: 12px;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--c-text-dim);
  text-decoration: none;
  transition: color 0.25s, background 0.25s, transform 0.25s;
}

.page-about .about-rail__item:hover,
.page-about .about-rail__item:focus-visible {
  color: var(--c-text);
  background: rgba(164, 75, 255, 0.12);
  transform: translateY(-1px);
  outline: none;
}

.page-about .about-rail__num {
  font-family: var(--font-data);
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--c-purple);
}

/* ===== 章节 ===== */
.page-about .about-section {
  scroll-margin-top: calc(var(--header-h, 72px) + 3rem);
  position: relative;
  padding: clamp(2.5rem, 5vw, 4.25rem) 0;
  border-top: 1px solid var(--about-line);
}

.page-about .about-section:first-child {
  padding-top: 0.5rem;
  border-top: 0;
}

.page-about .about-section__head {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  margin-bottom: 1.75rem;
}

.page-about .about-section__head .chapter-number {
  flex: 0 0 auto;
  font-family: var(--font-data);
  font-weight: 700;
  font-size: clamp(2.8rem, 5vw, 4.2rem);
  line-height: 0.9;
  background: linear-gradient(135deg, var(--c-purple), var(--c-cyan));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.page-about .about-section__head .section-title {
  margin: 0;
  font-family: var(--font-head);
  font-size: clamp(1.5rem, 2.6vw, 2.2rem);
  font-weight: 700;
  line-height: 1.25;
}

.page-about .section-head__note {
  margin: 0.35rem 0 0;
  font-size: 0.85rem;
  color: var(--c-text-dim);
}

.page-about .about-section:target {
  animation: about-section-target 1.4s ease;
}

/* ===== 品牌简介 ===== */
.page-about .about-intro__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
  align-items: center;
}

.page-about .about-intro__content>p {
  line-height: 1.75;
  font-size: 1rem;
  color: var(--c-text-dim);
}

.page-about .about-intro__content>p+p {
  margin-top: 0.9rem;
}

.page-about .about-intro__lead-text {
  font-size: 1.08rem !important;
  line-height: 1.8 !important;
  color: var(--c-text) !important;
}

.page-about .about-intro__values {
  display: grid;
  gap: 0.65rem;
  margin-top: 1.25rem;
}

.page-about .about-intro__value {
  display: flex;
  align-items: flex-start;
  gap: 0.8rem;
  padding: 0.85rem 1rem;
  background: rgba(26, 35, 64, 0.55);
  border: 1px solid var(--about-line);
  border-radius: 14px;
  font-size: 0.95rem;
  line-height: 1.6;
  color: var(--c-text-dim);
  transition: border-color 0.25s, transform 0.25s;
}

.page-about .about-intro__value:hover {
  border-color: rgba(164, 75, 255, 0.4);
  transform: translateX(2px);
}

.page-about .about-intro__value-key {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  border-radius: 10px;
  font-family: var(--font-data);
  font-size: 1rem;
  font-weight: 700;
  color: var(--c-white);
  background: linear-gradient(135deg, var(--c-purple), rgba(164, 75, 255, 0.55));
  box-shadow: 0 0 18px rgba(164, 75, 255, 0.28);
}

.page-about .about-intro__visual {
  margin: 0;
  position: relative;
  border-radius: var(--radius-card);
  overflow: hidden;
  background: linear-gradient(to bottom, rgba(26, 35, 64, 0.65), rgba(5, 7, 15, 0.5));
}

.page-about .about-intro__img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: var(--radius-card);
}

.page-about .about-intro__caption {
  display: block;
  padding: 0.85rem 1rem;
  font-size: 0.85rem;
  line-height: 1.6;
  color: var(--c-text-dim);
  background: rgba(11, 16, 38, 0.78);
  border-top: 1px solid var(--about-line);
}

/* ===== 发展历程 ===== */
.page-about .about-history__timeline {
  display: grid;
  gap: 1rem;
}

.page-about .about-history__item {
  display: grid;
  grid-template-columns: 1.8rem minmax(0, 1fr);
  gap: 0.75rem;
  position: relative;
}

.page-about .about-history__item:not(:last-child)::before {
  content: "";
  position: absolute;
  left: 0.82rem;
  top: 1.95rem;
  bottom: -1.1rem;
  width: 2px;
  background: linear-gradient(to bottom, rgba(164, 75, 255, 0.75), rgba(0, 229, 255, 0.12));
  border-radius: 999px;
}

.page-about .about-history__dot {
  position: relative;
  z-index: 1;
  justify-self: center;
  align-self: start;
  margin-top: 1.35rem;
  width: 0.95rem;
  height: 0.95rem;
  border-radius: 50%;
  background: var(--c-bg);
  border: 3px solid var(--c-purple);
  box-shadow: 0 0 0 5px rgba(164, 75, 255, 0.12), 0 0 24px rgba(164, 75, 255, 0.35);
}

.page-about .about-history__card {
  min-width: 0;
  padding: 1.25rem;
  border-radius: 18px;
}

.page-about .about-history__meta {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  margin-bottom: 0.7rem;
}

.page-about .about-history__year {
  font-family: var(--font-data);
  font-size: 1.35rem;
  font-weight: 700;
  line-height: 1;
  color: var(--c-cyan);
}

.page-about .about-history__badge {
  font-family: var(--font-data);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  padding: 0.28rem 0.6rem;
  border-radius: 999px;
  border: 1px solid rgba(164, 75, 255, 0.4);
  color: var(--c-purple);
}

.page-about .about-history__title {
  margin: 0 0 0.5rem;
  font-size: 1.08rem;
  font-weight: 700;
}

.page-about .about-history__desc {
  margin: 0;
  font-size: 0.94rem;
  line-height: 1.7;
  color: var(--c-text-dim);
}

.page-about .about-history__more {
  margin-top: 0.8rem;
  padding-top: 0.7rem;
  border-top: 1px solid var(--about-line);
  font-size: 0.88rem;
  color: var(--c-text-dim);
}

.page-about .about-history__more summary {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-data);
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  color: var(--c-cyan);
  user-select: none;
  transition: color 0.25s;
}

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

.page-about .about-history__more summary::after {
  content: "+";
  font-size: 1rem;
  font-weight: 700;
  color: var(--c-purple);
}

.page-about .about-history__more[open] summary::after {
  content: "–";
}

.page-about .about-history__more p,
.page-about .about-history__more ul {
  margin: 0.6rem 0 0;
  padding: 0;
  font-size: 0.85rem;
  line-height: 1.7;
}

.page-about .about-history__more ul {
  list-style: none;
}

.page-about .about-history__more li {
  position: relative;
  padding-left: 1rem;
  margin-bottom: 0.35rem;
}

.page-about .about-history__more li::before {
  content: "›";
  position: absolute;
  left: 0;
  color: var(--c-purple);
  font-weight: 700;
}

.page-about .about-history__visual {
  margin: 2rem 0 0;
}

.page-about .about-history__img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: var(--radius-card);
}

.page-about .about-history__visual figcaption {
  margin-top: 0.6rem;
  padding: 0 0.25rem;
  font-size: 0.85rem;
  line-height: 1.6;
  color: var(--c-text-dim);
}

/* ===== 数据规模 ===== */
.page-about .about-data__stats-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
}

.page-about .about-data__stat {
  padding: 1.35rem 1.2rem;
  border-radius: 18px;
  background: linear-gradient(150deg, rgba(26, 35, 64, 0.66), rgba(11, 16, 38, 0.42));
  border: 1px solid var(--about-line);
  transition: transform 0.3s, border-color 0.3s, box-shadow 0.3s;
}

.page-about .about-data__stat:hover {
  transform: translateY(-3px);
  border-color: rgba(57, 255, 136, 0.4);
  box-shadow: 0 8px 28px rgba(57, 255, 136, 0.08);
}

.page-about .about-data__num {
  display: block;
  font-family: var(--font-data);
  font-size: 2.5rem;
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--c-green);
  transition: text-shadow 0.3s;
}

.page-about .about-data__stat:hover .about-data__num {
  text-shadow: 0 0 24px rgba(57, 255, 136, 0.35);
}

.page-about .about-data__label {
  display: block;
  margin-top: 0.55rem;
  font-size: 0.96rem;
  font-weight: 600;
  line-height: 1.4;
}

.page-about .about-data__note {
  display: block;
  margin-top: 0.35rem;
  font-family: var(--font-data);
  font-size: 0.78rem;
  line-height: 1.5;
  color: var(--c-text-dim);
}

.page-about .about-data__update {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.25rem;
  padding: 1.25rem;
  border-radius: calc(var(--radius-card) - 2px);
  background: rgba(26, 35, 64, 0.4);
  border: 1px solid var(--about-line);
}

.page-about .about-data__update-title {
  margin: 0 0 0.85rem;
  font-family: var(--font-head);
  font-size: 1.45rem;
  line-height: 1.3;
}

.page-about .about-data__update-text p {
  margin: 0 0 0.85rem;
  font-size: 0.95rem;
  line-height: 1.75;
  color: var(--c-text-dim);
}

.page-about .about-data__trust {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.45rem 0.8rem;
  border-radius: 999px;
  background: rgba(57, 255, 136, 0.08);
  border: 1px solid rgba(57, 255, 136, 0.22);
  font-family: var(--font-data);
  font-size: 0.8rem;
  line-height: 1.5;
  color: var(--c-green);
}

.page-about .about-data__update-visual {
  margin: 0;
}

.page-about .about-data__img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: calc(var(--radius-card) - 6px);
}

.page-about .about-data__update-visual figcaption {
  margin-top: 0.6rem;
  font-size: 0.85rem;
  line-height: 1.6;
  color: var(--c-text-dim);
}

/* ===== 团队与生态 ===== */
.page-about .about-team__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.75rem;
}

.page-about .about-team__card {
  padding: 1.6rem 1.25rem;
  text-align: center;
  border-radius: 18px;
  transition: transform 0.3s, border-color 0.3s;
}

.page-about .about-team__card:hover {
  transform: translateY(-3px);
  border-color: rgba(164, 75, 255, 0.35);
}

.page-about .about-team__icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 3.2rem;
  height: 3.2rem;
  margin-bottom: 1rem;
  border-radius: 14px;
  font-family: var(--font-head);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--c-white);
  background: linear-gradient(145deg, var(--c-purple), #7b2fee);
  box-shadow: 0 0 30px rgba(164, 75, 255, 0.28);
}

.page-about .about-team__card h3 {
  margin: 0 0 0.5rem;
  font-size: 1.1rem;
  font-weight: 700;
}

.page-about .about-team__card p {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.7;
  color: var(--c-text-dim);
}

.page-about .about-team__trust {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.75rem;
  margin-top: 1.5rem;
}

.page-about .about-team__trust-item {
  padding: 1.15rem 1.25rem;
  border-radius: 0 16px 16px 0;
  border: 1px solid var(--about-line);
  border-left: 3px solid var(--c-cyan);
  background: rgba(11, 16, 38, 0.5);
}

.page-about .about-team__trust-item p {
  margin: 0.6rem 0 0;
  font-size: 0.88rem;
  line-height: 1.65;
  color: var(--c-text-dim);
}

/* ===== CTA 区块 ===== */
.page-about .about-cta {
  position: relative;
  margin: clamp(2.75rem, 6vw, 5rem) 0 clamp(3rem, 8vw, 6rem);
  padding: clamp(2rem, 5vw, 3.5rem);
  text-align: center;
  border-radius: calc(var(--radius-card) + 4px);
  border: 1px solid var(--about-line);
  background:
    radial-gradient(80% 100% at 15% 10%, rgba(164, 75, 255, 0.2), transparent),
    radial-gradient(70% 90% at 90% 90%, rgba(0, 229, 255, 0.14), transparent),
    linear-gradient(145deg, rgba(26, 35, 64, 0.8), rgba(5, 7, 15, 0.92));
  overflow: hidden;
}

.page-about .about-cta::before {
  content: "";
  position: absolute;
  top: -40%;
  left: 12%;
  width: 76%;
  height: 180%;
  background: linear-gradient(115deg, transparent 0%, rgba(164, 75, 255, 0.08) 45%, rgba(0, 229, 255, 0.1) 55%, transparent 100%);
  transform: rotate(8deg);
  pointer-events: none;
}

.page-about .about-cta__eyebrow {
  color: var(--c-orange);
}

.page-about .about-cta__title {
  margin: 0.5rem auto 0.85rem;
  max-width: 30em;
}

.page-about .about-cta__text {
  margin: 0 auto 1.5rem;
  max-width: 34em;
  font-size: 0.98rem;
  line-height: 1.7;
  color: var(--c-text-dim);
}

.page-about .about-cta__actions {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.75rem;
  position: relative;
  z-index: 1;
}

.page-about .about-cta__note {
  position: relative;
  z-index: 1;
  margin-top: 1.35rem;
  font-size: 0.88rem;
  color: var(--c-text-dim);
}

.page-about .about-cta__note a {
  color: var(--c-cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(0, 229, 255, 0.35);
}

.page-about .about-cta__note a:hover {
  color: var(--c-text);
}

/* ===== 交互增强 ===== */
.page-about:has(#brand-intro:target) .about-rail__item[href="#brand-intro"],
.page-about:has(#brand-history:target) .about-rail__item[href="#brand-history"],
.page-about:has(#brand-data:target) .about-rail__item[href="#brand-data"],
.page-about:has(#brand-team:target) .about-rail__item[href="#brand-team"] {
  color: var(--c-text);
  background: rgba(164, 75, 255, 0.16);
}

@keyframes about-section-target {
  0% {
    box-shadow: inset 0 0 0 2px rgba(164, 75, 255, 0.35);
  }
  100% {
    box-shadow: inset 0 0 0 2px transparent;
  }
}

/* ===== 桌面端增强 ===== */
@media (min-width: 600px) {
  .page-about .about-cta__actions {
    flex-direction: row;
    justify-content: center;
  }
}

@media (min-width: 640px) {
  .page-about .about-hero__stats {
    grid-template-columns: repeat(4, 1fr);
    gap: 0.85rem;
  }

  .page-about .about-data__stats-grid {
    grid-template-columns: 1fr 1fr;
    gap: 0.85rem;
  }

  .page-about .about-team__grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 0.85rem;
  }
}

@media (min-width: 700px) {
  .page-about .about-team__trust {
    grid-template-columns: repeat(3, 1fr);
    gap: 0.85rem;
  }
}

@media (min-width: 900px) {
  .page-about .about-layout {
    grid-template-columns: 250px minmax(0, 1fr);
    gap: clamp(2rem, 4vw, 4.5rem);
  }

  .page-about .about-rail {
    top: 1.5rem;
    flex-direction: column;
    align-items: stretch;
    gap: 0.3rem;
    overflow: visible;
    padding: 1rem;
  }

  .page-about .about-rail::before {
    content: "";
    position: absolute;
    left: 2rem;
    top: 4rem;
    bottom: 1.75rem;
    width: 2px;
    border-radius: 999px;
    background: linear-gradient(to bottom, rgba(164, 75, 255, 0.7), rgba(0, 229, 255, 0.2));
    opacity: 0.6;
    pointer-events: none;
  }

  .page-about .about-rail__label {
    position: relative;
    margin-bottom: 0.75rem;
    padding-bottom: 0.8rem;
    border-bottom: 1px solid var(--about-line);
  }

  .page-about .about-rail__item {
    position: relative;
    z-index: 1;
    padding: 0.65rem 0.9rem 0.65rem 2.2rem;
  }

  .page-about .about-rail__item:hover,
  .page-about .about-rail__item:focus-visible {
    transform: translateX(4px);
  }

  .page-about .about-rail__num {
    position: absolute;
    left: 0.75rem;
    top: 50%;
    transform: translateY(-50%);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 2.05rem;
    height: 2.05rem;
    border-radius: 50%;
    background: rgba(164, 75, 255, 0.1);
    border: 1px solid rgba(164, 75, 255, 0.35);
    font-size: 0.74rem;
  }

  .page-about .about-intro__grid {
    grid-template-columns: 1.05fr 0.95fr;
    gap: clamp(1.5rem, 3vw, 3rem);
  }

  .page-about .about-data__update {
    grid-template-columns: 0.9fr 1.1fr;
    gap: 1.75rem;
    padding: 1.75rem;
  }
}

@media (min-width: 1100px) {
  .page-about .about-data__stats-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}