.page-about {
  --about-sidebar-width: 280px;
  --about-gap: 40px;
  --about-section-gap: 48px;
  --about-number-size: 3rem;
  --about-accent-line: 3px;
  display: block;
  width: 100%;
  background: var(--primary-bg, #0a0a1a);
  color: var(--text-white, #ffffff);
  font-family: var(--font-body, 'Noto Sans SC', sans-serif);
}

/* ===== 移动端导航 ===== */
.about-mobile-nav {
  display: block;
  position: sticky;
  top: 0;
  z-index: 20;
  background: var(--secondary-bg, #1a1a2e);
  border-bottom: 1px solid var(--border-light, #2b2d42);
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
}
.about-mobile-nav::-webkit-scrollbar {
  display: none;
}
.about-mobile-nav__list {
  display: flex;
  gap: 4px;
  padding: 8px 12px;
  margin: 0;
  list-style: none;
  white-space: nowrap;
}
.about-mobile-nav__item {
  flex: 0 0 auto;
}
.about-mobile-nav__link {
  display: block;
  padding: 6px 16px;
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--text-gray, #8d99ae);
  background: transparent;
  border: 1px solid var(--border-light, #2b2d42);
  border-radius: 999px;
  text-decoration: none;
  transition: background var(--transition-fast, 0.2s), color var(--transition-fast, 0.2s), border-color var(--transition-fast, 0.2s);
}
.about-mobile-nav__link:focus-visible {
  outline: 2px solid var(--accent-yellow, #f9c74f);
  outline-offset: 2px;
}
.about-mobile-nav__link:hover {
  background: var(--border-light, #2b2d42);
  color: var(--text-white, #ffffff);
}
.about-mobile-nav__link:target,
.about-mobile-nav__link:active {
  background: var(--accent-red, #e63946);
  color: #fff;
  border-color: var(--accent-red, #e63946);
}

/* ===== 左右布局 ===== */
.about-layout {
  display: block;
  width: 100%;
  max-width: 100%;
}

/* ===== 左侧栏 ===== */
.about-sidebar {
  display: none;
}
.about-sidebar__sticky {
  position: sticky;
  top: 0;
  height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding: 32px 20px;
  background: var(--secondary-bg, #1a1a2e);
  border-right: 1px solid var(--border-light, #2b2d42);
}
.about-sidebar__brand-group {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  margin-bottom: 12px;
}
.about-sidebar__brand {
  font-family: var(--font-heading, 'Noto Sans SC', sans-serif);
  font-size: 1.375rem;
  font-weight: 700;
  color: var(--text-white, #ffffff);
  letter-spacing: -0.02em;
  line-height: 1.2;
}
.about-sidebar__rotated-label {
  display: inline-block;
  font-size: 0.6875rem;
  font-weight: 600;
  color: var(--accent-red, #e63946);
  writing-mode: vertical-rl;
  text-orientation: mixed;
  letter-spacing: 0.08em;
  opacity: 0.7;
  line-height: 1.4;
  transform: rotate(180deg);
}
.about-sidebar__tagline {
  font-size: 0.75rem;
  color: var(--text-gray, #8d99ae);
  letter-spacing: 0.04em;
  margin: 0 0 28px 0;
  padding-left: 2px;
  border-left: 2px solid var(--accent-yellow, #f9c74f);
  padding-left: 10px;
}
.about-sidebar__nav {
  display: flex;
  flex-direction: column;
  gap: 6px;
  flex: 1;
}
.about-sidebar__link {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 14px;
  text-decoration: none;
  color: var(--text-gray, #8d99ae);
  border-left: 3px solid transparent;
  transition: background var(--transition-fast, 0.2s), color var(--transition-fast, 0.2s), border-color var(--transition-fast, 0.2s);
  border-radius: 0 4px 4px 0;
}
.about-sidebar__link:hover {
  background: rgba(230, 57, 70, 0.08);
  color: var(--text-white, #ffffff);
  border-left-color: var(--accent-red, #e63946);
}
.about-sidebar__link:focus-visible {
  outline: 2px solid var(--accent-yellow, #f9c74f);
  outline-offset: 2px;
}
.about-sidebar__num {
  font-family: var(--font-heading, 'Noto Sans SC', sans-serif);
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--accent-red, #e63946);
  min-width: 24px;
  letter-spacing: -0.02em;
}
.about-sidebar__label {
  font-size: 0.9375rem;
  font-weight: 500;
  letter-spacing: 0.02em;
}
.about-sidebar__footer {
  padding-top: 20px;
  border-top: 1px solid var(--border-light, #2b2d42);
  margin-top: 20px;
}
.about-sidebar__home-link {
  display: inline-block;
  font-size: 0.8125rem;
  color: var(--text-gray, #8d99ae);
  text-decoration: none;
  padding: 6px 0;
  transition: color var(--transition-fast, 0.2s);
}
.about-sidebar__home-link:hover {
  color: var(--accent-yellow, #f9c74f);
}
.about-sidebar__home-link:focus-visible {
  outline: 2px solid var(--accent-yellow, #f9c74f);
  outline-offset: 2px;
}

/* ===== 右侧内容区 ===== */
.about-content {
  display: block;
  width: 100%;
  padding: 24px 16px 48px;
}

/* ===== 页面标题 ===== */
.about-page-header {
  margin-bottom: 40px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--border-light, #2b2d42);
}
.about-page-header__title {
  font-family: var(--font-heading, 'Noto Sans SC', sans-serif);
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--text-white, #ffffff);
  margin: 0 0 6px 0;
  letter-spacing: -0.02em;
}
.about-page-header__desc {
  font-size: 0.875rem;
  color: var(--text-gray, #8d99ae);
  margin: 0 0 12px 0;
  letter-spacing: 0.04em;
}
.about-page-header__line {
  width: 48px;
  height: 3px;
  background: var(--accent-red, #e63946);
}

/* ===== 章节 ===== */
.about-section {
  padding: 32px 0;
  border-bottom: 1px solid rgba(43, 45, 66, 0.5);
}
.about-section:last-of-type {
  border-bottom: none;
}
.about-section__header {
  display: flex;
  align-items: baseline;
  gap: 12px;
  margin-bottom: 12px;
}
.about-section__number {
  font-family: var(--font-heading, 'Noto Sans SC', sans-serif);
  font-size: var(--about-number-size, 3rem);
  font-weight: 700;
  color: var(--accent-red, #e63946);
  line-height: 1;
  letter-spacing: -0.03em;
}
.about-section__title {
  font-family: var(--font-heading, 'Noto Sans SC', sans-serif);
  font-size: 1.375rem;
  font-weight: 700;
  color: var(--text-white, #ffffff);
  margin: 0;
  letter-spacing: -0.01em;
}
.about-section__rotated-note {
  display: inline-block;
  font-size: 0.625rem;
  font-weight: 600;
  color: var(--accent-red, #e63946);
  writing-mode: vertical-rl;
  text-orientation: mixed;
  letter-spacing: 0.08em;
  opacity: 0.55;
  line-height: 1.3;
  margin-left: auto;
  transform: rotate(180deg);
}
.about-section__divider {
  width: 100%;
  height: 1px;
  background: linear-gradient(90deg, var(--accent-yellow, #f9c74f) 0%, transparent 80%);
  margin-bottom: 20px;
}
.about-section__body {
  display: flex;
  flex-direction: column;
  gap: 20px;
}
.about-section__body--reverse {
  flex-direction: column;
}
.about-section__text {
  flex: 1;
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--text-gray, #8d99ae);
}
.about-section__text p {
  margin: 0 0 16px 0;
}
.about-section__text p:last-child {
  margin-bottom: 0;
}

/* ===== 图片容器 ===== */
.about-section__image-wrap {
  margin: 0;
  flex-shrink: 0;
  border: 1px solid var(--border-light, #2b2d42);
  padding: 6px;
  background: var(--secondary-bg, #1a1a2e);
  border-radius: var(--radius-card, 4px);
  display: inline-block;
}
.about-section__image-wrap--brand {
  max-width: 200px;
}
.about-section__image-wrap--data {
  max-width: 100%;
}
.about-section__image-wrap--device {
  max-width: 150px;
}
.about-section__img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: contain;
  background: #12122a;
}
.about-section__caption {
  font-size: 0.6875rem;
  color: var(--text-gray, #8d99ae);
  text-align: center;
  padding: 6px 0 2px;
  letter-spacing: 0.04em;
}

/* ===== 功能列表 ===== */
.about-feature-list {
  list-style: none;
  padding: 0;
  margin: 16px 0;
  display: grid;
  gap: 8px;
}
.about-feature-list__item {
  position: relative;
  padding-left: 20px;
  font-size: 0.9375rem;
  color: var(--text-white, #ffffff);
  line-height: 1.5;
}
.about-feature-list__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.55em;
  width: 8px;
  height: 8px;
  background: var(--accent-red, #e63946);
  border-radius: 1px;
  transform: rotate(45deg);
}

/* ===== 内联链接 ===== */
.about-inline-link {
  display: inline-block;
  margin-top: 8px;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--accent-yellow, #f9c74f);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition-fast, 0.2s), color var(--transition-fast, 0.2s);
}
.about-inline-link:hover {
  color: var(--accent-red, #e63946);
  border-bottom-color: var(--accent-red, #e63946);
}
.about-inline-link:focus-visible {
  outline: 2px solid var(--accent-yellow, #f9c74f);
  outline-offset: 2px;
}

/* ===== 底部信任 ===== */
.about-trust {
  margin-top: 40px;
  padding: 24px 16px;
  background: var(--secondary-bg, #1a1a2e);
  border: 1px solid var(--border-light, #2b2d42);
  border-radius: var(--radius-card, 4px);
  text-align: center;
}
.about-trust__text {
  font-size: 0.8125rem;
  color: var(--text-gray, #8d99ae);
  margin: 0 0 8px 0;
  line-height: 1.6;
}
.about-trust__link {
  color: var(--accent-yellow, #f9c74f);
  text-decoration: underline;
  transition: color var(--transition-fast, 0.2s);
}
.about-trust__link:hover {
  color: var(--accent-red, #e63946);
}
.about-trust__icp {
  font-size: 0.6875rem;
  color: var(--text-gray, #8d99ae);
  margin: 0;
  letter-spacing: 0.04em;
}

/* ===== 滚动显现 ===== */
[data-reveal] {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity var(--transition-reveal, 0.5s cubic-bezier(0.23, 1, 0.32, 1)),
              transform var(--transition-reveal, 0.5s cubic-bezier(0.23, 1, 0.32, 1));
}
[data-reveal].is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== 桌面端 ===== */
@media (min-width: 768px) {
  .about-mobile-nav {
    display: none;
  }
  .about-sidebar {
    display: block;
    position: fixed;
    top: 0;
    left: 0;
    width: var(--about-sidebar-width, 280px);
    height: 100vh;
    z-index: 10;
  }
  .about-layout {
    padding-left: var(--about-sidebar-width, 280px);
  }
  .about-content {
    padding: 48px 40px 64px;
    max-width: 860px;
  }
  .about-page-header {
    margin-bottom: 48px;
    padding-bottom: 24px;
  }
  .about-page-header__title {
    font-size: 2.25rem;
  }
  .about-page-header__desc {
    font-size: 1rem;
  }
  .about-section {
    padding: 40px 0;
  }
  .about-section__number {
    font-size: 3.5rem;
  }
  .about-section__title {
    font-size: 1.625rem;
  }
  .about-section__body {
    flex-direction: row;
    align-items: flex-start;
    gap: 32px;
  }
  .about-section__body--reverse {
    flex-direction: row-reverse;
  }
  .about-section__image-wrap--data {
    max-width: 380px;
  }
  .about-feature-list {
    grid-template-columns: 1fr 1fr;
    gap: 10px 24px;
  }
  .about-section__text {
    font-size: 1rem;
  }
  .about-trust {
    padding: 32px 40px;
  }
}

@media (min-width: 1024px) {
  .about-content {
    padding: 56px 48px 80px;
    max-width: 920px;
  }
  .about-section__number {
    font-size: 4rem;
  }
  .about-section__title {
    font-size: 1.75rem;
  }
  .about-section__image-wrap--data {
    max-width: 420px;
  }
}

/* ===== 减少动效 ===== */
@media (prefers-reduced-motion: reduce) {
  [data-reveal] {
    opacity: 1;
    transform: none;
    transition: none;
  }
  .about-sidebar__link,
  .about-inline-link,
  .about-mobile-nav__link {
    transition: none;
  }
}