.page-about {
  --about-toc-top: 92px;
  background: var(--color-cream);
  color: var(--color-ink);
  font-family: var(--font-body);
  line-height: 1.75;
}

.page-about .about-breadcrumbs {
  padding-top: 24px;
  padding-bottom: 4px;
}

.page-about .breadcrumbs__list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--color-metal);
}

.page-about .breadcrumbs__item + .breadcrumbs__item::before {
  content: "/";
  margin-right: 8px;
  color: var(--color-metal);
}

.page-about .breadcrumbs__link {
  color: var(--color-red);
  text-decoration: none;
  transition: opacity 0.2s;
}

.page-about .breadcrumbs__link:hover {
  opacity: 0.8;
}

.page-about .about-hero {
  position: relative;
  overflow: hidden;
  background: var(--color-space);
  color: #fff;
  padding: 40px 0 48px;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -80px;
  right: -80px;
  width: 280px;
  height: 280px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(229, 101, 47, 0.28), transparent 70%);
  pointer-events: none;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  height: 3px;
  background: linear-gradient(90deg, var(--color-red) 0%, var(--color-orange) 60%, transparent 100%);
}

.page-about .about-hero__kicker {
  margin: 0 0 16px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-metal);
}

.page-about .about-hero__title {
  margin: 0 0 20px;
  font-family: var(--font-heading);
  font-size: 32px;
  line-height: 1.3;
  max-width: 820px;
}

.page-about .about-hero__lead {
  margin: 0 0 32px;
  font-size: 16px;
  line-height: 1.8;
  color: var(--color-info);
  max-width: 680px;
}

.page-about .about-hero__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 28px;
  padding-top: 22px;
  border-top: 1px solid rgba(255, 255, 255, 0.14);
}

.page-about .about-hero__meta-item {
  position: relative;
  padding-left: 14px;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--color-metal);
}

.page-about .about-hero__meta-item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 8px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--color-red);
}

.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 32px;
  padding-top: 36px;
  padding-bottom: 64px;
}

.page-about .about-content {
  min-width: 0;
}

.page-about .about-section {
  padding: 40px 0;
  border-bottom: 1px solid rgba(138, 147, 165, 0.28);
  scroll-margin-top: 96px;
}

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

.page-about .about-section__head {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding-left: 12px;
  border-left: 3px solid transparent;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  margin-bottom: 16px;
  transition: border-color 0.3s;
}

.page-about .about-section__page {
  font-weight: 700;
  color: var(--color-orange);
}

.page-about .about-section__chapter {
  color: var(--color-metal);
  letter-spacing: 0.1em;
}

.page-about .about-section__title {
  margin: 0 0 14px;
  font-family: var(--font-heading);
  font-size: 26px;
  line-height: 1.35;
  color: var(--color-ink);
}

.page-about .about-section__lead,
.page-about .about-section__desc {
  font-size: 15px;
  line-height: 1.9;
  color: var(--color-ink);
  max-width: 720px;
}

.page-about .about-section__lead {
  font-size: 18px;
  line-height: 1.7;
  color: var(--color-space-deep);
  margin-bottom: 20px;
}

.page-about .about-section__desc {
  margin-bottom: 28px;
}

.page-about .about-section:target .about-section__head {
  border-left-color: var(--color-red);
}

.page-about .about-section:target .about-section__title {
  color: var(--color-red);
}

.page-about .about-intro__col {
  margin-top: 20px;
}

.page-about .about-intro__col p {
  margin: 0 0 16px;
  line-height: 2;
  color: var(--color-ink);
}

.page-about .about-timeline {
  margin: 28px 0 24px;
  padding: 24px 20px;
  background: var(--color-info);
  border-radius: 14px;
}

.page-about .about-timeline__svg {
  display: none;
}

.page-about .about-timeline__notes {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-timeline__notes li {
  position: relative;
  margin: 0 0 16px 6px;
  padding: 0 0 0 24px;
  border-left: 2px solid var(--color-metal);
}

.page-about .about-timeline__notes li:last-child {
  margin-bottom: 0;
}

.page-about .about-timeline__notes li::before {
  content: "";
  position: absolute;
  left: -7px;
  top: 4px;
  width: 12px;
  height: 12px;
  box-sizing: border-box;
  border-radius: 50%;
  background: var(--color-cream);
  border: 3px solid var(--color-red);
}

.page-about .about-tl-node circle {
  transition: stroke 0.2s, stroke-width 0.2s, fill 0.2s;
}

.page-about .about-tl-node:hover circle {
  stroke: var(--color-orange);
  stroke-width: 4;
}

.page-about .about-tl-sub {
  font-family: var(--font-mono);
  font-size: 14px;
  fill: var(--color-metal);
}

.page-about .about-version__img,
.page-about .about-scale__img,
.page-about .about-principles__img {
  display: block;
  max-width: 100%;
  height: auto;
  border-radius: 10px;
  margin-top: 24px;
  box-shadow: 0 14px 32px rgba(10, 30, 60, 0.14);
}

.page-about .about-scale__grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin: 24px 0;
}

.page-about .about-scale__stat {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 128px;
  overflow: hidden;
  border-radius: 12px;
  background: var(--color-space);
  color: #fff;
}

.page-about .about-scale__stat::after {
  content: "";
  position: absolute;
  right: -20px;
  bottom: -20px;
  width: 76px;
  height: 76px;
  border-radius: 50%;
  border: 10px solid rgba(201, 55, 46, 0.25);
  pointer-events: none;
}

.page-about .about-scale__num {
  position: relative;
  z-index: 1;
  font-family: var(--font-heading);
  font-size: 42px;
  font-weight: 700;
  line-height: 1.1;
  color: #fff;
}

.page-about .about-scale__unit {
  position: relative;
  z-index: 1;
  margin-top: 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--color-metal);
  letter-spacing: 0.06em;
}

.page-about .about-scale__body p {
  margin: 0 0 16px;
  line-height: 1.9;
  color: var(--color-ink);
}

.page-about .about-principles__list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-principles__item {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 16px;
  padding: 24px 0;
  border-top: 1px solid rgba(138, 147, 165, 0.3);
}

.page-about .about-principles__item:last-child {
  border-bottom: 1px solid rgba(138, 147, 165, 0.3);
}

.page-about .about-principles__num {
  font-family: var(--font-mono);
  font-size: 16px;
  font-weight: 700;
  color: var(--color-orange);
  padding-top: 2px;
}

.page-about .about-principles__title {
  margin: 0 0 8px;
  font-family: var(--font-heading);
  font-size: 19px;
  color: var(--color-space-deep);
}

.page-about .about-principles__body p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--color-ink);
}

.page-about .about-license__card {
  margin-top: 20px;
  padding: 24px 20px;
  border-radius: 12px;
  border-left: 4px solid var(--color-red);
  background: var(--color-info);
}

.page-about .about-license__list {
  margin: 0;
  padding: 0;
}

.page-about .about-license__row {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  padding: 10px 0;
  border-bottom: 1px solid rgba(43, 33, 28, 0.12);
}

.page-about .about-license__row:last-child {
  border-bottom: none;
}

.page-about .about-license__row dt {
  flex-shrink: 0;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--color-metal);
}

.page-about .about-license__row dd {
  margin: 0;
  text-align: right;
  font-size: 15px;
  font-weight: 500;
  color: var(--color-ink);
}

.page-about .about-license__card .note-box {
  margin-top: 20px;
}

.page-about .about-next {
  margin-top: 40px;
  padding-top: 32px;
}

.page-about .about-next__code {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--color-metal);
}

.page-about .about-next__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
  margin-top: 16px;
}

.page-about .about-next__link {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 16px 18px;
  border: 1px solid rgba(138, 147, 165, 0.4);
  border-radius: 10px;
  color: var(--color-ink);
  text-decoration: none;
  transition: background 0.2s, border-color 0.2s, transform 0.2s;
}

.page-about .about-next__link:hover {
  background: var(--color-info);
  border-color: var(--color-red);
  transform: translateX(4px);
}

.page-about .about-next__index {
  flex-shrink: 0;
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 700;
  color: var(--color-red);
}

.page-about .about-next__text {
  font-size: 15px;
}

.page-about .about-toc {
  position: sticky;
  top: var(--about-toc-top);
  z-index: 40;
  align-self: start;
  padding: 14px 16px;
  border: 1px solid rgba(138, 147, 165, 0.35);
  border-radius: 10px;
  background: rgba(245, 240, 230, 0.92);
  backdrop-filter: blur(8px);
}

.page-about .about-toc__heading {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 8px;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--color-metal);
}

.page-about .about-toc__desc {
  display: none;
}

.page-about .about-toc__list {
  display: flex;
  gap: 6px;
  margin: 0;
  padding: 0 0 4px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .about-toc__item {
  flex-shrink: 0;
}

.page-about .about-toc__link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  border: 1px solid rgba(138, 147, 165, 0.4);
  border-radius: 50px;
  font-size: 13px;
  color: var(--color-ink);
  text-decoration: none;
  white-space: nowrap;
  transition: border-color 0.2s, color 0.2s;
}

.page-about .about-toc__link:hover {
  border-color: var(--color-red);
  color: var(--color-red);
}

.page-about .about-toc__link:focus-visible,
.page-about .about-next__link:focus-visible {
  outline: 2px solid var(--color-red);
  outline-offset: 2px;
}

.page-about .about-toc__num {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--color-orange);
}

.page-about .about-toc__status {
  display: none;
}

@media (min-width: 768px) {
  .page-about .about-hero__title {
    font-size: 38px;
  }

  .page-about .about-intro__col {
    column-count: 2;
    column-gap: 40px;
  }

  .page-about .about-intro__col p {
    break-inside: avoid;
  }

  .page-about .about-scale__grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 20px;
  }

  .page-about .about-scale__stat {
    min-height: 150px;
  }

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

@media (min-width: 1024px) {
  .page-about .about-hero {
    padding: 64px 0 76px;
  }

  .page-about .about-hero__title {
    font-size: 44px;
  }

  .page-about .about-hero__lead {
    font-size: 18px;
    margin-bottom: 40px;
  }

  .page-about .about-layout {
    grid-template-columns: 240px minmax(0, 1fr);
    gap: 64px;
    padding-top: 48px;
    padding-bottom: 80px;
  }

  .page-about .about-toc {
    padding: 0;
    border: none;
    border-radius: 0;
    background: transparent;
    backdrop-filter: none;
  }

  .page-about .about-toc__heading {
    display: block;
    margin-bottom: 20px;
  }

  .page-about .about-toc__code {
    display: block;
    font-size: 13px;
    letter-spacing: 0.1em;
    color: var(--color-red);
  }

  .page-about .about-toc__desc {
    display: block;
    margin-top: 6px;
    font-size: 12px;
    color: var(--color-metal);
  }

  .page-about .about-toc__list {
    flex-direction: column;
    gap: 0;
    padding: 0;
    overflow: visible;
    border-left: 1px solid rgba(138, 147, 165, 0.4);
  }

  .page-about .about-toc__item {
    flex-shrink: 1;
  }

  .page-about .about-toc__link {
    display: flex;
    align-items: baseline;
    gap: 12px;
    margin-left: -1px;
    padding: 10px 0 10px 20px;
    border: none;
    border-left: 2px solid transparent;
    border-radius: 0;
    white-space: normal;
    font-size: 15px;
  }

  .page-about .about-toc__link:hover {
    border-left-color: var(--color-red);
    color: var(--color-red);
  }

  .page-about .about-toc__status {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-top: 24px;
    font-family: var(--font-mono);
    font-size: 12px;
    color: var(--color-metal);
  }

  .page-about .about-toc__status-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--color-red);
    animation: about-pulse 2s ease-out infinite;
  }

  .page-about .about-section {
    padding: 48px 0;
  }

  .page-about .about-section__title {
    font-size: 30px;
  }

  .page-about .about-timeline {
    padding: 36px 32px;
  }

  .page-about .about-timeline__svg {
    display: block;
    width: 100%;
    height: auto;
    margin-bottom: 24px;
  }

  .page-about .about-timeline__notes {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
  }

  .page-about .about-timeline__notes li {
    margin: 0;
    padding: 16px 0 0;
    border-left: none;
    border-top: 3px solid var(--color-red);
  }

  .page-about .about-timeline__notes li::before {
    left: 0;
    top: -7px;
  }

  .page-about .about-principles__item {
    gap: 24px;
    padding: 28px 0;
  }

  .page-about .about-principles__num {
    font-size: 18px;
  }

  .page-about .about-license__card {
    padding: 32px;
  }
}

@keyframes about-pulse {
  0%,
  100% {
    box-shadow: 0 0 0 0 rgba(201, 55, 46, 0.5);
  }

  50% {
    box-shadow: 0 0 0 8px rgba(201, 55, 46, 0);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-toc__status-dot {
    animation: none;
  }

  .page-about .about-next__link {
    transition: none;
  }

  .page-about .about-next__link:hover {
    transform: none;
  }

  .page-about .about-tl-node circle {
    transition: none;
  }

  .page-about .about-section__head,
  .page-about .about-section__title {
    transition: none;
  }
}