.page-about {
  --about-orange: #FF6B00;
  --about-deep-blue: #0A1F44;
  --about-night-blue: #071428;
  --about-lime: #C6FF00;
  --about-electric: #00D4FF;
  --about-gray: #F3F5F7;
  --about-ink: #1A2A3A;
  --about-purple: #8B5CF6;
  --about-grid-line: rgba(10, 31, 68, 0.08);
  --about-accent-line: rgba(0, 212, 255, 0.35);
  --about-orange-soft: rgba(255, 107, 0, 0.12);
  font-family: var(--font-sans, "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif);
  background: var(--about-gray);
  background-image:
    linear-gradient(var(--about-grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--about-grid-line) 1px, transparent 1px);
  background-size: 40px 40px;
  color: var(--about-ink);
}

.page-about__shell {
  max-width: 1440px;
  margin: 0 auto;
  padding: 0 20px;
  position: relative;
}

.page-about__breadcrumb {
  margin-bottom: 24px;
  padding-top: 16px;
}

.page-about__coordinate {
  font-family: var(--font-mono, "JetBrains Mono", monospace);
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin-bottom: 12px;
}

.page-about__intro {
  position: relative;
  padding: 32px 0 48px;
  border-bottom: 2px solid var(--about-ink);
}

.page-about__intro::after {
  content: "";
  position: absolute;
  bottom: -1px;
  right: 0;
  width: 96px;
  height: 4px;
  background: var(--about-orange);
}

.page-about__intro-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
}

.page-about__title {
  font-family: var(--font-display, "Anton", "Noto Sans SC", sans-serif);
  font-size: clamp(28px, 5.2vw, 52px);
  line-height: 1.05;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: -0.01em;
  margin: 0 0 20px;
  color: var(--about-deep-blue);
}

.page-about__lead {
  font-size: 16px;
  line-height: 1.8;
  color: var(--about-ink);
  max-width: 720px;
  margin: 0 0 14px;
}

.page-about__lead--strong {
  font-weight: 700;
  color: var(--about-deep-blue);
  border-left: 3px solid var(--about-orange);
  padding-left: 14px;
}

.page-about__intro-mark {
  position: relative;
  min-height: 140px;
  display: none;
  align-items: center;
  justify-content: center;
  background: var(--about-deep-blue);
  background-image:
    linear-gradient(rgba(0, 212, 255, 0.15) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 212, 255, 0.15) 1px, transparent 1px);
  background-size: 20px 20px;
  border: 1px solid var(--about-electric);
  overflow: hidden;
}

.page-about__intro-mark-line {
  position: absolute;
  top: 0;
  left: 24px;
  width: 2px;
  height: 100%;
  background: linear-gradient(to bottom, var(--about-orange), var(--about-electric));
}

.page-about__intro-mark-circle {
  font-family: var(--font-display, "Anton", "Noto Sans SC", sans-serif);
  font-size: 40px;
  color: var(--about-lime);
  border: 2px solid var(--about-lime);
  border-radius: 50%;
  width: 120px;
  height: 120px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(198, 255, 0, 0.06);
}

.page-about__intro-mark-label {
  position: absolute;
  bottom: 12px;
  right: 16px;
  font-family: var(--font-mono, "JetBrains Mono", monospace);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--about-electric);
}

.page-about__section-head {
  padding: 56px 0 28px;
  display: flex;
  flex-direction: column;
}

.page-about__section-title {
  font-family: var(--font-display, "Anton", "Noto Sans SC", sans-serif);
  font-size: clamp(26px, 4vw, 40px);
  line-height: 1.1;
  margin: 0 0 12px;
  color: var(--about-deep-blue);
  text-transform: uppercase;
}

.page-about__section-desc {
  font-size: 16px;
  line-height: 1.7;
  color: var(--about-ink);
  max-width: 640px;
}

.page-about__timeline {
  position: relative;
  padding-bottom: 24px;
}

.page-about__timeline-axis {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 16px;
  width: 2px;
  background: linear-gradient(to bottom, var(--about-orange), var(--about-electric) 60%, var(--about-purple));
  z-index: 0;
}

.page-about__timeline-axis::before {
  content: "";
  position: absolute;
  top: -8px;
  left: -4px;
  width: 10px;
  height: 10px;
  background: var(--about-orange);
  border-radius: 50%;
}

.page-about__timeline-axis::after {
  content: "";
  position: absolute;
  bottom: -8px;
  left: -4px;
  width: 10px;
  height: 10px;
  background: var(--about-purple);
  border-radius: 50%;
}

.page-about__timeline-axis-label {
  position: absolute;
  top: 0;
  left: 12px;
  font-family: var(--font-mono, "JetBrains Mono", monospace);
  font-size: 10px;
  color: var(--about-electric);
  writing-mode: vertical-rl;
  letter-spacing: 0.18em;
  padding: 4px 0;
}

.page-about__timeline-intro {
  position: relative;
  z-index: 1;
  padding-left: 44px;
  margin-bottom: 24px;
}

.page-about__timeline-item {
  position: relative;
  z-index: 1;
  padding-left: 44px;
  margin-bottom: 32px;
}

.page-about__timeline-item--center {
  padding-left: 44px;
}

.page-about__timeline-node {
  position: absolute;
  left: 8px;
  top: 8px;
  width: 20px;
  height: 20px;
  background: var(--about-deep-blue);
  border: 3px solid var(--about-orange);
  border-radius: 50%;
  z-index: 2;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.page-about__timeline-node::before {
  content: attr(aria-label);
  position: absolute;
  left: 28px;
  top: 50%;
  transform: translateY(-50%);
  font-family: var(--font-mono, "JetBrains Mono", monospace);
  font-size: 11px;
  font-weight: 700;
  color: var(--about-deep-blue);
  white-space: nowrap;
  background: rgba(243, 245, 247, 0.92);
  padding: 2px 6px;
  border: 1px solid var(--about-node-border, #d1d9e3);
}

.page-about__timeline-node:hover,
.page-about__timeline-node:focus-visible {
  transform: scale(1.25);
  box-shadow: 0 0 0 6px var(--about-orange-soft);
  outline: none;
}

.page-about__timeline-node:hover::before,
.page-about__timeline-node:focus-visible::before {
  color: var(--about-orange);
}

.page-about__milestone-card {
  background: rgba(255, 255, 255, 0.85);
  border: 1px solid #d8dfe8;
  padding: 24px 20px;
  position: relative;
}

.page-about__milestone-card::before {
  content: "";
  position: absolute;
  top: -1px;
  left: -1px;
  width: 28px;
  height: 28px;
  border-top: 3px solid var(--about-orange);
  border-left: 3px solid var(--about-orange);
  pointer-events: none;
}

.page-about__milestone-card--intro {
  background: rgba(255, 255, 255, 0.92);
  margin-bottom: 8px;
}

.page-about__milestone-num {
  font-family: var(--font-mono, "JetBrains Mono", monospace);
  font-size: 12px;
  color: var(--about-orange);
  font-weight: 700;
  margin-bottom: 8px;
}

.page-about__milestone-title {
  font-family: var(--font-display, "Anton", "Noto Sans SC", sans-serif);
  font-size: 22px;
  margin: 0 0 10px;
  color: var(--about-deep-blue);
  text-transform: uppercase;
}

.page-about__milestone-text {
  font-size: 14px;
  line-height: 1.75;
  margin: 0 0 12px;
}

.page-about__milestone-link,
.page-about__team-link {
  margin: 0;
}

.page-about__milestone-link a,
.page-about__team-link a {
  color: var(--about-orange);
  font-weight: 700;
  text-decoration: none;
  font-size: 14px;
  border-bottom: 1px solid transparent;
}

.page-about__milestone-link a:hover,
.page-about__team-link a:hover {
  border-bottom-color: var(--about-orange);
}

.page-about__media-card {
  margin: 20px 0 0;
  display: block;
  background: var(--about-deep-blue);
  padding: 6px;
  border: 1px solid #b8c4d2;
  box-shadow: 6px 6px 0 rgba(10, 31, 68, 0.08);
}

.page-about__media-card--w800 {
  max-width: 560px;
}

.page-about__media-card--w1200 {
  max-width: 720px;
}

.page-about__media-card--principle {
  max-width: 560px;
}

.page-about__media-img {
  display: block;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  width: 100%;
}

.page-about__media-caption {
  font-family: var(--font-mono, "JetBrains Mono", monospace);
  font-size: 11px;
  color: rgba(255, 255, 255, 0.8);
  padding: 8px 4px 2px;
  letter-spacing: 0.06em;
}

.page-about__timeline-item--center .page-about__media-card {
  margin-top: 0;
}

.page-about__section-head--team {
  padding-top: 48px;
  border-top: 2px solid var(--about-ink);
}

.page-about__team-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
  margin-bottom: 32px;
}

.page-about__team-card {
  background: #ffffff;
  border: 1px solid #e2e8f0;
  padding: 28px 24px;
  position: relative;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.page-about__team-card:hover {
  transform: translateY(-3px);
  box-shadow: 8px 8px 0 rgba(10, 31, 68, 0.06);
}

.page-about__team-code {
  font-family: var(--font-display, "Anton", sans-serif);
  font-size: 48px;
  position: absolute;
  top: 12px;
  right: 18px;
  color: rgba(10, 31, 68, 0.08);
  line-height: 1;
}

.page-about__team-title {
  font-size: 18px;
  font-weight: 700;
  color: var(--about-deep-blue);
  margin: 0 0 10px;
  font-family: var(--font-sans, "Noto Sans SC", sans-serif);
}

.page-about__team-text {
  font-size: 14px;
  line-height: 1.75;
  color: var(--about-ink);
  margin: 0 0 14px;
}

.page-about__team-scale {
  background: var(--about-deep-blue);
  color: #ffffff;
  padding: 32px 24px;
  position: relative;
  background-image:
    linear-gradient(rgba(0, 212, 255, 0.1) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 212, 255, 0.1) 1px, transparent 1px);
  background-size: 28px 28px;
}

.page-about__team-scale::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background: var(--about-lime);
}

.page-about__team-scale-title {
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--about-lime);
  text-transform: uppercase;
  margin: 0 0 18px;
  font-family: var(--font-mono, "JetBrains Mono", monospace);
}

.page-about__team-scale-meta {
  display: flex;
  align-items: center;
  gap: 20px;
  flex-wrap: wrap;
}

.page-about__scale-num {
  font-family: var(--font-display, "Anton", sans-serif);
  font-size: clamp(56px, 8vw, 88px);
  line-height: 0.9;
  color: var(--about-lime);
  white-space: nowrap;
}

.page-about__scale-unit {
  font-size: 20px;
  margin-left: 4px;
}

.page-about__scale-text {
  font-size: 14px;
  line-height: 1.75;
  color: rgba(255, 255, 255, 0.85);
  max-width: 420px;
}

.page-about__qualification-section {
  padding-top: 16px;
}

.page-about__qualification-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}

.page-about__qualification-card {
  background: #ffffff;
  border: 1px solid #e2e8f0;
  border-top: 4px solid var(--about-electric);
  padding: 28px 24px;
}

.page-about__qualification-card--dark {
  background: var(--about-night-blue);
  border-top-color: var(--about-orange);
}

.page-about__qualification-card--dark .page-about__qualification-title {
  color: var(--about-lime);
}

.page-about__qualification-card--dark .page-about__qualification-text {
  color: rgba(255, 255, 255, 0.82);
}

.page-about__qualification-title {
  font-size: 18px;
  font-weight: 700;
  color: var(--about-deep-blue);
  margin: 0 0 12px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.page-about__qualification-title::before {
  content: "";
  width: 8px;
  height: 8px;
  background: var(--about-orange);
  display: inline-block;
}

.page-about__qualification-text {
  font-size: 14px;
  line-height: 1.75;
  margin: 0;
}

.page-about__principles-section {
  padding-top: 56px;
}

.page-about__principles-section .page-about__section-head {
  border-top: 2px solid var(--about-ink);
  margin-top: 24px;
}

.page-about__principles-wrap {
  background: rgba(255, 255, 255, 0.7);
  border: 1px solid #d8dfe8;
  padding: 24px 20px;
  position: relative;
}

.page-about__principles-wrap::before,
.page-about__principles-wrap::after {
  content: "";
  position: absolute;
  width: 48px;
  height: 48px;
  pointer-events: none;
  z-index: 1;
}

.page-about__principles-wrap::before {
  top: -1px;
  right: -1px;
  border-top: 3px solid var(--about-lime);
  border-right: 3px solid var(--about-lime);
}

.page-about__principles-wrap::after {
  bottom: -1px;
  left: -1px;
  border-bottom: 3px solid var(--about-lime);
  border-left: 3px solid var(--about-lime);
}

.page-about__principles-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
}

.page-about__principle-item {
  position: relative;
  padding: 0 0 0 0;
}

.page-about__principle-index {
  font-family: var(--font-mono, "JetBrains Mono", monospace);
  font-size: 12px;
  color: var(--about-orange);
  font-weight: 700;
  letter-spacing: 0.06em;
}

.page-about__principle-title {
  font-size: 18px;
  font-weight: 700;
  color: var(--about-deep-blue);
  margin: 6px 0 8px;
  font-family: var(--font-sans, "Noto Sans SC", sans-serif);
}

.page-about__principle-text {
  font-size: 14px;
  line-height: 1.75;
  margin: 0;
}

.page-about__closing {
  padding: 72px 0 80px;
}

.page-about__closing-paper {
  background: #ffffff;
  border: 1px solid #d8dfe8;
  padding: 40px 24px;
  position: relative;
  box-shadow: 12px 12px 0 rgba(10, 31, 68, 0.08);
  background-image:
    linear-gradient(var(--about-grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--about-grid-line) 1px, transparent 1px);
  background-size: 32px 32px;
}

.page-about__closing-paper::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 6px;
  background: linear-gradient(to right, var(--about-orange), var(--about-electric), var(--about-lime));
}

.page-about__closing-paper::after {
  content: "";
  position: absolute;
  bottom: -8px;
  right: 24px;
  width: 80px;
  height: 8px;
  background: var(--about-deep-blue);
}

.page-about__closing-tag {
  font-family: var(--font-mono, "JetBrains Mono", monospace);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--about-electric);
  margin-bottom: 14px;
  text-transform: uppercase;
}

.page-about__closing-title {
  font-family: var(--font-display, "Anton", "Noto Sans SC", sans-serif);
  font-size: clamp(24px, 3.6vw, 34px);
  color: var(--about-deep-blue);
  line-height: 1.1;
  margin: 0 0 16px;
  text-transform: uppercase;
}

.page-about__closing-text {
  font-size: 15px;
  line-height: 1.8;
  color: var(--about-ink);
  max-width: 680px;
  margin: 0 0 28px;
}

.page-about__closing-links {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}

@media (min-width: 640px) {
  .page-about__shell {
    padding: 0 32px;
  }

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

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

  .page-about__principles-grid {
    grid-template-columns: repeat(2, 1fr);
    column-gap: 36px;
  }

  .page-about__closing-paper {
    padding: 48px 40px;
  }
}

@media (min-width: 768px) {
  .page-about__intro-grid {
    grid-template-columns: 1.6fr 1fr;
    gap: 48px;
    align-items: stretch;
  }

  .page-about__intro-mark {
    display: flex;
  }

  .page-about__intro {
    padding: 48px 0 64px;
  }

  .page-about__timeline-axis {
    left: 50%;
    margin-left: -1px;
  }

  .page-about__timeline-axis-label {
    left: 16px;
  }

  .page-about__timeline-intro {
    width: 50%;
    padding-left: 0;
    padding-right: 48px;
    text-align: right;
    margin-bottom: 40px;
  }

  .page-about__timeline-intro .page-about__milestone-card {
    text-align: left;
  }

  .page-about__timeline-item {
    width: 50%;
    padding-left: 0;
    margin-bottom: 48px;
  }

  .page-about__timeline-item--left {
    padding-right: 48px;
    text-align: right;
  }

  .page-about__timeline-item--left .page-about__timeline-node {
    left: auto;
    right: -10px;
  }

  .page-about__timeline-item--left .page-about__timeline-node::before {
    left: auto;
    right: 28px;
    white-space: nowrap;
  }

  .page-about__timeline-item--left .page-about__milestone-card {
    text-align: left;
  }

  .page-about__timeline-item--right {
    margin-left: 50%;
    padding-left: 48px;
  }

  .page-about__timeline-item--right .page-about__timeline-node {
    left: -10px;
  }

  .page-about__timeline-item--center {
    width: 50%;
    margin-left: 25%;
    padding-left: 48px;
    margin-bottom: 48px;
  }

  .page-about__timeline-item--center .page-about__timeline-node {
    display: none;
  }

  .page-about__timeline-item--center .page-about__media-card {
    margin-left: 0;
    margin-right: auto;
  }

  .page-about__timeline-intro .page-about__timeline-node {
    right: -10px;
    left: auto;
    top: 8px;
  }

  .page-about__timeline-intro .page-about__timeline-node::before {
    left: auto;
    right: 28px;
  }

  .page-about__timeline-intro {
    position: relative;
    z-index: 1;
  }

  .page-about__timeline-intro .page-about__milestone-card {
    margin-right: 0;
  }
}

@media (min-width: 1024px) {
  .page-about__shell {
    padding: 0 48px;
  }

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

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

  .page-about__principles-grid {
    grid-template-columns: repeat(2, 1fr);
    column-gap: 56px;
    row-gap: 40px;
  }

  .page-about__principles-grid .page-about__media-card {
    grid-column: 1 / -1;
    max-width: 720px;
    margin-left: 0;
  }

  .page-about__section-head {
    flex-direction: row;
    flex-wrap: wrap;
    align-items: baseline;
    gap: 24px;
  }

  .page-about__section-title {
    margin-bottom: 0;
  }

  .page-about__section-desc {
    flex-basis: 100%;
  }
}

@media (prefers-reduced-motion: no-preference) {
  .page-about__media-card {
    transition: box-shadow 0.3s ease;
  }

  .page-about__media-card:hover {
    box-shadow: 10px 10px 0 rgba(10, 31, 68, 0.14);
  }

  .page-about__intro-mark-circle {
    animation: page-about-pulse 4s ease-in-out infinite;
  }
}

@keyframes page-about-pulse {
  0%, 100% {
    box-shadow: 0 0 0 0 rgba(198, 255, 0, 0.15);
  }
  50% {
    box-shadow: 0 0 0 18px rgba(198, 255, 0, 0);
  }
}

.page-about__timeline-item [data-reveal="true"],
.page-about__section-head [data-reveal="true"],
.page-about__principles-wrap [data-reveal="true"] {
  opacity: 1;
}

@media (min-width: 768px) {
  .page-about__timeline-item--left .page-about__milestone-card {
    margin-right: 0;
  }

  .page-about__timeline-item--right .page-about__timeline-node::before {
    left: 28px;
    right: auto;
  }

  .page-about__timeline-item--right .page-about__timeline-node::before {
    content: attr(aria-label);
  }

  .page-about__timeline-item--center .page-about__media-card {
    margin-top: 0;
  }

  .page-about__closing {
    padding-left: 0;
    padding-right: 0;
  }

  .page-about__closing-paper {
    padding: 64px 56px;
  }
}

.page-about {
  --about-node-border: currentColor;
}