/* ===== 页面专属: page-about ===== */
.page-about {
  --page-accent: var(--color-accent, #D4AF37);
  --page-primary: var(--color-primary, #0B1A2C);
  --page-purple: var(--color-purple, #7B2D8B);
  --page-green: var(--color-green, #39FF14);
  --page-white: var(--color-white, #FFFFFF);
  --page-light: var(--color-light, #F0F0F0);
  --page-text: var(--color-text, #0B1A2C);
  --page-font-heading: var(--font-heading, 'Inter', 'PingFang SC', 'Microsoft YaHei', sans-serif);
  --page-font-body: var(--font-body, 'Inter', 'PingFang SC', 'Microsoft YaHei', sans-serif);
  --page-font-accent: var(--font-accent, 'Space Mono', 'Courier New', monospace);
  --page-max-width: var(--max-width, 1200px);
  --page-radius: var(--radius, 4px);
  --page-shadow-stack: var(--shadow-stack, 0 4px 20px rgba(0,0,0,0.08), 0 1px 4px rgba(0,0,0,0.04));
  --page-border-gold: var(--border-gold, 2px solid var(--color-accent, #D4AF37));
  --page-nav-height: var(--nav-height, 64px);
  --page-section-gap: clamp(3rem, 6vw, 6rem);
  --page-card-bg: rgba(255,255,255,0.04);
  --page-card-border: 1px solid rgba(212,175,55,0.2);
}

/* 跳转辅助 */
.page-about .skip-link:focus {
  outline: 2px solid var(--page-accent);
  outline-offset: 4px;
}

/* ===== 首屏 hero ===== */
.page-about__hero {
  position: relative;
  padding: 2rem 1rem 3rem;
  background: var(--page-primary);
  overflow: hidden;
  min-height: 70vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
}
.page-about__hero-shape {
  position: absolute;
  top: -20%;
  right: -15%;
  width: 60%;
  height: 80%;
  background: linear-gradient(135deg, var(--page-purple) 0%, transparent 70%);
  opacity: 0.25;
  transform: rotate(12deg);
  pointer-events: none;
}
.page-about__hero-shape--alt {
  top: auto;
  bottom: -10%;
  left: -10%;
  width: 40%;
  height: 50%;
  background: linear-gradient(225deg, var(--page-accent) 0%, transparent 60%);
  opacity: 0.12;
  transform: rotate(-8deg);
}
.page-about__hero-inner {
  position: relative;
  z-index: 2;
  max-width: var(--page-max-width);
  margin: 0 auto;
  width: 100%;
  display: flex;
  flex-direction: column;
  gap: 2rem;
}
.page-about__hero-text {
  position: relative;
}
.page-about__hero-label {
  position: relative;
  display: inline-block;
  margin-bottom: 1rem;
  color: var(--page-accent);
  font-family: var(--page-font-accent);
  font-size: 0.7rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  writing-mode: vertical-rl;
  transform: rotate(180deg);
  transform-origin: center;
  opacity: 0.7;
}
.page-about__hero-suptitle {
  font-family: var(--page-font-heading);
  font-weight: 400;
  font-size: clamp(0.8rem, 1.2vw, 1.1rem);
  color: var(--page-accent);
  letter-spacing: 0.2em;
  text-transform: uppercase;
  margin: 0 0 0.5rem;
}
.page-about__hero-title {
  font-family: var(--page-font-heading);
  font-weight: 800;
  font-size: clamp(2.8rem, 8vw, 6rem);
  color: var(--page-white);
  line-height: 1.05;
  margin: 0 0 0.75rem;
  letter-spacing: -0.02em;
}
.page-about__hero-sub {
  font-family: var(--page-font-body);
  font-weight: 300;
  font-size: clamp(1rem, 2vw, 1.4rem);
  color: var(--page-light);
  letter-spacing: 0.08em;
  margin: 0;
  opacity: 0.8;
}
.page-about__hero-image {
  position: relative;
  max-width: 600px;
  width: 100%;
  margin: 1rem 0 0;
}
.page-about__hero-img {
  width: 100%;
  height: auto;
  max-height: 400px;
  object-fit: cover;
  border-radius: var(--page-radius);
  box-shadow: var(--page-shadow-stack);
  display: block;
}
.page-about__hero-tag {
  position: absolute;
  bottom: -0.5rem;
  right: -0.5rem;
  font-size: 0.7rem;
  padding: 0.2rem 0.6rem;
}
.page-about__hero-index {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-top: 2rem;
  flex-wrap: wrap;
}
.page-about__hero-number {
  font-size: clamp(2rem, 4vw, 3rem);
  color: var(--page-accent);
  opacity: 0.5;
  font-weight: 800;
}
.page-about__hero-line {
  flex: 1;
  min-width: 40px;
  max-width: 120px;
  height: 1px;
  background: var(--page-accent);
  opacity: 0.4;
}
.page-about__hero-nav {
  display: flex;
  gap: 1.2rem;
  flex-wrap: wrap;
}
.page-about__hero-nav-link {
  font-family: var(--page-font-accent);
  font-size: 0.72rem;
  color: var(--page-light);
  text-decoration: none;
  letter-spacing: 0.05em;
  transition: color 0.2s;
  position: relative;
}
.page-about__hero-nav-link::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 1px;
  background: var(--page-accent);
  transition: width 0.25s;
}
.page-about__hero-nav-link:hover,
.page-about__hero-nav-link:focus-visible {
  color: var(--page-accent);
}
.page-about__hero-nav-link:hover::after,
.page-about__hero-nav-link:focus-visible::after {
  width: 100%;
}

/* ===== 通用章节 ===== */
.page-about__section {
  padding: var(--page-section-gap) 1rem;
  position: relative;
}
.page-about__section:nth-child(odd) {
  background: var(--page-white);
}
.page-about__section:nth-child(even) {
  background: var(--page-light);
}
.page-about__section-inner {
  max-width: var(--page-max-width);
  margin: 0 auto;
  width: 100%;
}
.page-about__section-header {
  display: flex;
  align-items: baseline;
  gap: 1rem;
  margin-bottom: 2.5rem;
  flex-wrap: wrap;
  position: relative;
}
.page-about__section-number {
  font-size: clamp(2.5rem, 5vw, 4rem);
  font-weight: 800;
  color: var(--page-accent);
  opacity: 0.3;
  line-height: 1;
  font-family: var(--page-font-heading);
}
.page-about__section-heading {
  font-family: var(--page-font-heading);
  font-weight: 800;
  font-size: clamp(1.6rem, 3.5vw, 2.6rem);
  color: var(--page-primary);
  margin: 0;
  letter-spacing: -0.01em;
}
.page-about__section-label {
  color: var(--page-primary);
  opacity: 0.4;
  font-family: var(--page-font-accent);
  font-size: 0.65rem;
  text-transform: uppercase;
  writing-mode: vertical-rl;
  transform: rotate(180deg);
  transform-origin: center;
  margin-left: auto;
  letter-spacing: 0.1em;
}

/* ===== 01 名称解码 ===== */
.page-about__name-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
}
.page-about__name-card {
  padding: 2rem 1.5rem;
  background: var(--page-white);
  border: var(--page-card-border);
  border-radius: var(--page-radius);
  position: relative;
  transition: transform 0.25s, box-shadow 0.25s;
}
.page-about__name-card:hover,
.page-about__name-card:focus-within {
  transform: translateY(-4px);
  box-shadow: 0 12px 40px rgba(11,26,44,0.12);
}
.page-about__name-tag {
  display: inline-block;
  margin-bottom: 1rem;
  font-size: 0.65rem;
  padding: 0.15rem 0.6rem;
}
.page-about__name-title {
  font-family: var(--page-font-heading);
  font-weight: 800;
  font-size: clamp(1.4rem, 2.5vw, 2rem);
  color: var(--page-primary);
  margin: 0 0 0.75rem;
}
.page-about__name-desc {
  font-family: var(--page-font-body);
  font-size: 0.95rem;
  line-height: 1.7;
  color: var(--page-text);
  margin: 0 0 1rem;
  opacity: 0.85;
}
.page-about__name-line {
  height: 1px;
  background: var(--page-accent);
  opacity: 0.3;
  margin: 0.75rem 0;
}
.page-about__name-extra {
  font-family: var(--page-font-accent);
  font-size: 0.75rem;
  color: var(--page-accent);
  margin: 0;
  letter-spacing: 0.04em;
  font-style: italic;
}

/* ===== 02 版本对照 ===== */
.page-about__version-intro {
  font-family: var(--page-font-body);
  font-size: 1rem;
  color: var(--page-text);
  opacity: 0.75;
  max-width: 600px;
  margin: 0 0 2rem;
  line-height: 1.6;
}
.page-about__version-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
  margin-bottom: 2rem;
}
.page-about__version-card {
  perspective: 1000px;
  min-height: 240px;
  cursor: pointer;
  transition: filter 0.3s;
}
.page-about__version-card[data-hover-dim]:hover ~ .page-about__version-card:not(:hover) {
  filter: brightness(0.92);
}
.page-about__version-card-inner {
  position: relative;
  width: 100%;
  height: 100%;
  transition: transform 0.5s ease;
  transform-style: preserve-3d;
  border-radius: var(--page-radius);
  border: var(--page-card-border);
  background: var(--page-white);
  box-shadow: var(--page-shadow-stack);
}
.page-about__version-card:hover .page-about__version-card-inner,
.page-about__version-card:focus-visible .page-about__version-card-inner {
  transform: rotateY(180deg);
}
.page-about__version-card-front,
.page-about__version-card-back {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 1.5rem;
  backface-visibility: hidden;
  border-radius: var(--page-radius);
}
.page-about__version-card-front {
  background: var(--page-white);
  z-index: 2;
}
.page-about__version-card-back {
  background: var(--page-primary);
  color: var(--page-white);
  transform: rotateY(180deg);
  z-index: 1;
}
.page-about__version-tag {
  display: inline-block;
  margin-bottom: 0.6rem;
  font-size: 0.6rem;
  padding: 0.15rem 0.5rem;
  align-self: flex-start;
}
.page-about__version-title {
  font-family: var(--page-font-heading);
  font-weight: 800;
  font-size: clamp(1.2rem, 2vw, 1.6rem);
  color: var(--page-primary);
  margin: 0 0 0.5rem;
}
.page-about__version-card-front .page-about__version-title {
  color: var(--page-primary);
}
.page-about__version-brief {
  font-family: var(--page-font-body);
  font-size: 0.9rem;
  color: var(--page-text);
  opacity: 0.7;
  margin: 0;
}
.page-about__version-hint {
  font-family: var(--page-font-accent);
  font-size: 0.65rem;
  color: var(--page-accent);
  margin-top: 1rem;
  opacity: 0.6;
}
.page-about__version-detail {
  font-family: var(--page-font-body);
  font-size: 0.88rem;
  line-height: 1.6;
  color: var(--page-white);
  margin: 0;
  opacity: 0.92;
}
.page-about__version-image-wrap {
  position: relative;
  max-width: 700px;
  margin: 2rem auto 0;
}
.page-about__version-img {
  width: 100%;
  height: auto;
  max-height: 400px;
  object-fit: cover;
  border-radius: var(--page-radius);
  box-shadow: var(--page-shadow-stack);
  display: block;
}
.page-about__version-img-tag {
  position: absolute;
  top: -0.4rem;
  left: -0.4rem;
  font-size: 0.65rem;
  padding: 0.15rem 0.5rem;
}

/* ===== 03 愿景 ===== */
.page-about__vision-content {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
}
.page-about__vision-text {
  display: flex;
  flex-direction: column;
  gap: 1.2rem;
}
.page-about__vision-paragraph {
  font-family: var(--page-font-body);
  font-size: 1rem;
  line-height: 1.8;
  color: var(--page-text);
  margin: 0;
  opacity: 0.88;
}
.page-about__vision-em {
  color: var(--page-accent);
  font-weight: 600;
}
.page-about__vision-line {
  height: 2px;
  width: 80px;
  background: var(--page-accent);
  opacity: 0.5;
  margin: 0.5rem 0;
}
.page-about__vision-tagline {
  font-family: var(--page-font-accent);
  font-size: 0.85rem;
  color: var(--page-accent);
  margin: 0;
  letter-spacing: 0.06em;
}
.page-about__vision-image {
  position: relative;
  max-width: 800px;
  width: 100%;
}
.page-about__vision-img {
  width: 100%;
  height: auto;
  max-height: 450px;
  object-fit: cover;
  border-radius: var(--page-radius);
  box-shadow: var(--page-shadow-stack);
  display: block;
}
.page-about__vision-img-tag {
  position: absolute;
  bottom: -0.4rem;
  right: -0.4rem;
  font-size: 0.65rem;
  padding: 0.15rem 0.5rem;
}

/* ===== 底部导航 ===== */
.page-about__footer-nav {
  padding: 2rem 1rem 3rem;
  background: var(--page-primary);
  border-top: 1px solid rgba(212,175,55,0.25);
}
.page-about__footer-nav-inner {
  max-width: var(--page-max-width);
  margin: 0 auto;
  width: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}
.page-about__footer-nav-link {
  font-family: var(--page-font-accent);
  font-size: 0.8rem;
  color: var(--page-accent);
  text-decoration: none;
  letter-spacing: 0.06em;
  transition: opacity 0.2s;
  padding: 0.3rem 0;
  border-bottom: 1px solid transparent;
}
.page-about__footer-nav-link:hover,
.page-about__footer-nav-link:focus-visible {
  opacity: 0.7;
  border-bottom-color: var(--page-accent);
}

/* ===== 响应式: 平板及以上 ===== */
@media (min-width: 640px) {
  .page-about__hero-inner {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }
  .page-about__hero-text {
    flex: 1 1 50%;
  }
  .page-about__hero-image {
    flex: 1 1 40%;
    margin: 0;
  }
  .page-about__hero-index {
    margin-top: 3rem;
  }
  .page-about__section {
    padding: var(--page-section-gap) 2rem;
  }
  .page-about__name-grid {
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
  }
  .page-about__version-grid {
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
  }
  .page-about__version-card {
    min-height: 280px;
  }
  .page-about__vision-content {
    grid-template-columns: 1fr 1fr;
    align-items: center;
  }
  .page-about__vision-image {
    order: 2;
  }
  .page-about__vision-text {
    order: 1;
  }
}

@media (min-width: 960px) {
  .page-about__hero {
    min-height: 80vh;
    padding: 3rem 2rem 4rem;
  }
  .page-about__hero-title {
    font-size: clamp(4rem, 7vw, 6.5rem);
  }
  .page-about__version-card {
    min-height: 320px;
  }
  .page-about__version-card-front,
  .page-about__version-card-back {
    padding: 2rem;
  }
  .page-about__name-card {
    padding: 2.5rem 2rem;
  }
}

/* ===== 打印样式精简 ===== */
@media print {
  .page-about__hero {
    min-height: auto;
    padding: 1rem 0;
    background: var(--page-white) !important;
  }
  .page-about__hero-title {
    color: var(--page-primary);
  }
  .page-about__hero-shape,
  .page-about__hero-shape--alt,
  .page-about__version-card-back {
    display: none !important;
  }
  .page-about__version-card-inner {
    transform: none !important;
  }
  .page-about__version-card-front {
    position: static;
    backface-visibility: visible;
  }
  .page-about__version-hint {
    display: none;
  }
  .page-about__footer-nav {
    background: var(--page-light);
  }
}