.page-standards {
  --std-rail-w: 176px;
  --std-fig-a: calc(var(--text-3xl) * 2);
  --std-fig-b: calc(var(--text-3xl) * 1.46);
  --std-fig-c: calc(var(--text-3xl) * 1.09);
  background: var(--color-surface);
  color: var(--color-ink);
  font-family: var(--font-body);
  line-height: var(--leading-body);
}

.page-standards :focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 2px;
}

/* ---------- 面包屑 ---------- */
.page-standards .std-breadcrumb {
  margin-bottom: var(--space-6);
}
.page-standards .std-breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-1);
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: var(--text-sm);
  color: var(--color-ink-muted);
}
.page-standards .std-breadcrumb a {
  color: var(--color-ink-soft);
  text-decoration: none;
  border-bottom: var(--border-thin) solid var(--color-line);
}
.page-standards .std-breadcrumb a:hover {
  color: var(--color-primary);
  border-bottom-color: var(--color-primary);
}

/* ---------- 首屏封面 ---------- */
.page-standards .std-cover {
  padding-top: var(--space-6);
  padding-bottom: 0;
}
.page-standards .std-cover__head {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
}
.page-standards .std-cover__rule {
  display: block;
  width: 40px;
  height: 2px;
  background: var(--color-primary);
}
.page-standards .std-cover__title {
  margin: var(--space-4) 0 var(--space-4);
  font-family: var(--font-heading);
  font-size: var(--text-display);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  text-align: center;
  color: var(--color-ink);
}
.page-standards .std-cover__lead {
  max-width: 54ch;
  margin: 0 auto;
  text-align: center;
  font-size: var(--text-lg);
  line-height: 1.6;
  color: var(--color-ink-soft);
}

/* ---------- 反色数字带 ---------- */
.page-standards .std-figures {
  margin-top: var(--space-8);
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border: var(--border-thin) solid var(--color-contrast-line);
  position: relative;
}
.page-standards .std-figures::after {
  content: "";
  position: absolute;
  inset: 4px;
  border: var(--border-thin) solid var(--color-contrast-line);
  pointer-events: none;
}
.page-standards .std-figures__inner {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--space-4);
  padding: var(--space-6) var(--space-4);
}
.page-standards .std-figures__item {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}
.page-standards .std-figures__value {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  line-height: 1;
  letter-spacing: 0;
  color: var(--color-contrast-ink);
}
.page-standards .std-figures__value--a {
  font-size: var(--std-fig-a);
}
.page-standards .std-figures__value--b {
  font-size: var(--std-fig-b);
  color: var(--color-contrast-accent);
}
.page-standards .std-figures__value--c {
  font-size: var(--std-fig-c);
}
.page-standards .std-figures__label {
  font-size: var(--text-sm);
  letter-spacing: 0.06em;
  color: var(--color-contrast-ink);
  opacity: 0.72;
}
.page-standards .std-figures__index {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  padding-top: var(--space-3);
  border-top: var(--border-thin) solid var(--color-contrast-line);
}
.page-standards .std-figures__index a {
  color: var(--color-contrast-ink);
  text-decoration: none;
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  padding-bottom: 2px;
  border-bottom: var(--border-thin) solid transparent;
}
.page-standards .std-figures__index a:hover,
.page-standards .std-figures__index a:focus-visible {
  color: var(--color-contrast-accent);
  border-bottom-color: var(--color-contrast-accent);
}

@media (min-width: 780px) {
  .page-standards .std-figures__inner {
    grid-template-columns: auto auto auto minmax(0, 1fr);
    align-items: end;
    gap: var(--space-8);
    padding: var(--space-8) var(--space-6);
  }
  .page-standards .std-figures__index {
    flex-direction: column;
    align-items: flex-end;
    text-align: right;
    gap: var(--space-1);
    padding-top: 0;
    border-top: 0;
    border-left: var(--border-thin) solid var(--color-contrast-line);
    padding-left: var(--space-4);
  }
}

/* ---------- 主体骨架 ---------- */
.page-standards .std-body {
  padding: var(--section-y) 0;
}
.page-standards .std-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--space-6);
}

/* ---------- 左侧时间轴 ---------- */
.page-standards .std-rail {
  min-width: 0;
}
.page-standards .std-rail__head {
  margin: 0 0 var(--space-2);
  font-size: var(--text-xs);
  letter-spacing: 0.16em;
  color: var(--color-ink-muted);
}
.page-standards .std-rail__list {
  display: flex;
  gap: var(--space-1);
  margin: 0;
  padding: 0 0 var(--space-2);
  list-style: none;
  overflow-x: auto;
  scrollbar-width: thin;
}
.page-standards .std-rail__link {
  display: flex;
  align-items: baseline;
  gap: var(--space-2);
  padding: var(--space-2);
  color: var(--color-ink-soft);
  text-decoration: none;
  font-size: var(--text-sm);
  white-space: nowrap;
  border-left: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-sm);
  transition: background-color 240ms cubic-bezier(0.2, 0.7, 0.2, 1),
    color 240ms cubic-bezier(0.2, 0.7, 0.2, 1),
    border-color 240ms cubic-bezier(0.2, 0.7, 0.2, 1);
}
.page-standards .std-rail__link:hover,
.page-standards .std-rail__link:focus-visible {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border-left-color: var(--color-contrast-accent);
}
.page-standards .std-rail__link:hover .std-rail__num,
.page-standards .std-rail__link:focus-visible .std-rail__num {
  color: var(--color-contrast-accent);
}
.page-standards .std-rail__num {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-primary);
}

@media (min-width: 900px) {
  .page-standards .std-shell {
    grid-template-columns: var(--std-rail-w) minmax(0, 1fr);
    gap: var(--space-8);
  }
  .page-standards .std-rail {
    position: sticky;
    top: 112px;
    align-self: start;
  }
  .page-standards .std-rail__list {
    flex-direction: column;
    gap: 0;
    overflow: visible;
    padding-bottom: 0;
    border-top: var(--border-thin) solid var(--color-line);
  }
  .page-standards .std-rail__link {
    border-left: 0;
    border-bottom: var(--border-thin) solid var(--color-line);
  }
}

/* ---------- 内容区与区块 ---------- */
.page-standards .std-main {
  display: flex;
  flex-direction: column;
  gap: var(--section-y);
  min-width: 0;
}
.page-standards .std-block {
  scroll-margin-top: 120px;
}
.page-standards .std-block__head {
  border-top: 3px double var(--color-line);
  padding-top: var(--space-4);
}
.page-standards .std-block__eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  margin: 0;
  font-size: var(--text-sm);
  letter-spacing: 0.1em;
  color: var(--color-primary);
}
.page-standards .std-block__eyebrow::before {
  content: "";
  width: 24px;
  height: 2px;
  background: var(--color-primary);
}
.page-standards .std-block__title {
  margin: var(--space-3) 0 var(--space-3);
  font-family: var(--font-heading);
  font-size: var(--text-2xl);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
}
.page-standards .std-block__lead {
  max-width: var(--measure);
  margin: 0;
  color: var(--color-ink-soft);
  line-height: var(--leading-body);
}
.page-standards .std-block__note {
  max-width: var(--measure);
  margin: var(--space-4) 0 0;
  padding-left: var(--space-3);
  border-left: 2px solid var(--color-primary);
  color: var(--color-ink-soft);
  line-height: var(--leading-body);
}

/* ---------- 阶段列表 ---------- */
.page-standards .std-stages {
  margin: var(--space-6) 0 0;
  padding: 0;
  list-style: none;
  border-top: var(--border-thin) solid var(--color-line);
}
.page-standards .std-stages__row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--space-1);
  padding: var(--space-3) 0;
  border-bottom: var(--border-thin) solid var(--color-line);
}
.page-standards .std-stages__range {
  margin: 0;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--text-sm);
  color: var(--color-ink-muted);
}
.page-standards .std-stages__name {
  margin: 0;
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: var(--weight-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
}
.page-standards .std-stages__desc {
  margin: 0;
  color: var(--color-ink-soft);
  line-height: 1.7;
}
.page-standards .std-stages__count {
  margin: 0;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--text-sm);
  color: var(--color-accent);
}
.page-standards .std-stages__count .num {
  font-size: var(--text-lg);
}

@media (min-width: 760px) {
  .page-standards .std-stages__row {
    grid-template-columns: 118px 148px minmax(0, 1fr) 84px;
    align-items: baseline;
    gap: var(--space-3);
  }
  .page-standards .std-stages__count {
    text-align: right;
  }
}

/* ---------- 图片 ---------- */
.page-standards .std-figure {
  margin: var(--space-6) 0 0;
}
.page-standards .std-figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
}
@media (min-width: 760px) {
  .page-standards .std-figure--narrow {
    max-width: 76%;
  }
}

/* ---------- 案例 ---------- */
.page-standards .std-cases {
  margin-top: var(--space-6);
}
.page-standards .std-case {
  padding: var(--space-6) 0;
  border-top: var(--border-thin) solid var(--color-line);
}
.page-standards .std-case--last {
  border-bottom: var(--border-thin) solid var(--color-line);
}
.page-standards .std-case__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: var(--space-3);
}
.page-standards .std-case__no {
  flex: none;
  padding: 2px 8px;
  background: var(--color-primary);
  color: var(--color-primary-ink);
  font-size: var(--text-xs);
  letter-spacing: 0.14em;
  border-radius: var(--radius-sm);
}
.page-standards .std-case__title {
  margin: 0;
  font-family: var(--font-heading);
  font-size: var(--text-xl);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
}
.page-standards .std-case__inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--space-4);
  margin-top: var(--space-4);
}
.page-standards .std-case__step + .std-case__step {
  margin-top: var(--space-3);
}
.page-standards .std-case__label {
  display: block;
  margin-bottom: var(--space-1);
  font-size: var(--text-xs);
  letter-spacing: 0.16em;
  color: var(--color-ink-muted);
}
.page-standards .std-case__label--invert {
  color: var(--color-contrast-accent);
}
.page-standards .std-case__step p {
  margin: 0;
  line-height: var(--leading-body);
  color: var(--color-ink);
}
.page-standards .std-case__outcome {
  align-self: start;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  padding: var(--space-4);
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border: var(--border-thin) solid var(--color-contrast-line);
  border-radius: var(--radius-sm);
}
.page-standards .std-case__figure {
  margin: 0;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--text-figure);
  line-height: 1;
  color: var(--color-contrast-ink);
}
.page-standards .std-case__unit {
  margin-left: 0.15em;
  font-size: var(--text-lg);
  color: var(--color-contrast-accent);
}
.page-standards .std-case__note {
  margin: 0;
  font-size: var(--text-sm);
  line-height: 1.7;
  color: var(--color-contrast-ink);
  opacity: 0.82;
}

@media (min-width: 760px) {
  .page-standards .std-case__inner {
    grid-template-columns: 7fr 5fr;
    gap: var(--space-6);
  }
}

/* ---------- 反色小标记 ---------- */
.page-standards .std-chip {
  display: inline-block;
  padding: 0 var(--space-1);
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  border-radius: var(--radius-sm);
}

/* ---------- 复核工序 ---------- */
.page-standards .std-check {
  margin: var(--space-6) 0 0;
  padding: 0;
  list-style: none;
}
.page-standards .std-check__item {
  position: relative;
  padding: 0 0 var(--space-6) var(--space-6);
  border-left: var(--border-thin) solid var(--color-line);
}
.page-standards .std-check__item:last-child {
  padding-bottom: 0;
  border-left-color: transparent;
}
.page-standards .std-check__no {
  position: absolute;
  left: 0;
  top: 0;
  transform: translateX(-50%);
  display: grid;
  place-items: center;
  width: 24px;
  height: 24px;
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  border-radius: var(--radius-sm);
}
.page-standards .std-check__title {
  margin: 0 0 var(--space-1);
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: var(--weight-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
}
.page-standards .std-check__owner {
  margin: 0 0 var(--space-2);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-accent);
}
.page-standards .std-check__body {
  max-width: var(--measure);
  margin: 0;
  color: var(--color-ink-soft);
  line-height: var(--leading-body);
}

/* ---------- 更新窗口 ---------- */
.page-standards .std-windows {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--space-3);
  margin-top: var(--space-6);
}
.page-standards .std-window {
  padding: var(--space-4);
  border: 3px double var(--color-line);
  border-radius: var(--radius-sm);
}
.page-standards .std-window--invert {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border-color: var(--color-contrast-line);
}
.page-standards .std-window__time {
  margin: 0 0 var(--space-2);
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--text-lg);
  color: var(--color-primary);
}
.page-standards .std-window--invert .std-window__time {
  color: var(--color-contrast-accent);
}
.page-standards .std-window__what {
  margin: 0;
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}
.page-standards .std-window--invert .std-window__what {
  color: var(--color-contrast-ink);
  opacity: 0.86;
}

@media (min-width: 720px) {
  .page-standards .std-windows {
    grid-template-columns: 7fr 5fr;
    gap: var(--space-4);
  }
}

/* ---------- 出口 ---------- */
.page-standards .std-exits {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--space-3);
  margin-top: var(--space-6);
}
.page-standards .std-exit {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--space-2);
  padding: var(--space-4);
  border: 3px double var(--color-line);
  border-radius: var(--radius-sm);
  text-decoration: none;
  color: var(--color-ink);
  transition: background-color 240ms cubic-bezier(0.2, 0.7, 0.2, 1),
    color 240ms cubic-bezier(0.2, 0.7, 0.2, 1),
    border-color 240ms cubic-bezier(0.2, 0.7, 0.2, 1);
}
.page-standards .std-exit:hover,
.page-standards .std-exit:focus-visible {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border-color: var(--color-contrast-line);
}
.page-standards .std-exit__label {
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  letter-spacing: var(--tracking-heading);
  color: var(--color-primary);
}
.page-standards .std-exit:hover .std-exit__label,
.page-standards .std-exit:focus-visible .std-exit__label {
  color: var(--color-contrast-accent);
}
.page-standards .std-exit__text {
  display: block;
  font-size: var(--text-sm);
  line-height: 1.8;
  color: var(--color-ink-soft);
}
.page-standards .std-exit:hover .std-exit__text,
.page-standards .std-exit:focus-visible .std-exit__text {
  color: var(--color-contrast-ink);
}

@media (min-width: 720px) {
  .page-standards .std-exits {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: var(--space-4);
  }
}

/* ---------- 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-standards .reveal {
    transform: none;
    transition: none;
  }
  .page-standards .std-rail__link,
  .page-standards .std-exit {
    transition: none;
  }
}