.page-disclaimer {
  padding-block: clamp(20px, 3vw, 34px) clamp(64px, 9vw, 104px);
}

.page-disclaimer .breadcrumb {
  margin-bottom: clamp(18px, 3vw, 30px);
}

/* ---------- 页首 ---------- */
.usage-head {
  padding-bottom: clamp(24px, 3.6vw, 38px);
}

.usage-head h1 {
  margin: 0 0 18px;
  max-width: 11em;
  font-size: clamp(30px, 6vw, 52px);
  font-weight: 700;
  line-height: 1.08;
  letter-spacing: -0.01em;
  color: var(--white-100);
}

.usage-lede {
  max-width: var(--measure);
  margin: 0;
  font-size: 16px;
  line-height: 1.85;
  color: var(--silver-200);
}

/* ---------- 主题视觉 ---------- */
.usage-cover {
  margin: 0 0 clamp(30px, 4.4vw, 48px);
  border: 1px solid var(--line-700);
  background: var(--ink-800);
}

.usage-cover img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  aspect-ratio: 16 / 7;
  object-fit: cover;
}

.usage-cover figcaption {
  padding: 10px 14px;
  border-top: 1px solid var(--line-700);
  font-size: 12.5px;
  letter-spacing: 0.02em;
  line-height: 1.6;
  color: var(--silver-500);
}

/* ---------- 章节 ---------- */
.rule-block {
  display: grid;
  gap: 10px;
  padding-block: clamp(28px, 4vw, 46px);
  border-top: 1px solid var(--line-700);
}

.rule-block__num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: 0.08em;
  color: var(--green-500);
}

.rule-block__title {
  margin: 0 0 14px;
  font-size: clamp(22px, 3.4vw, 30px);
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.01em;
  color: var(--white-100);
}

.rule-block__more {
  border-left: 2px solid var(--line-700);
  padding-left: 18px;
  transition: border-color var(--ease);
}

.rule-block__more[open] {
  border-left-color: var(--green-500);
}

.rule-block__more > summary {
  position: relative;
  list-style: none;
  padding-right: 26px;
  font-size: 16.5px;
  font-weight: 700;
  line-height: 1.7;
  color: var(--white-100);
  cursor: pointer;
  transition: color var(--ease);
}

.rule-block__more > summary::-webkit-details-marker {
  display: none;
}

.rule-block__more > summary::after {
  content: "+";
  position: absolute;
  right: 0;
  top: 0;
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 400;
  line-height: 1.9;
  color: var(--green-500);
}

.rule-block__more[open] > summary::after {
  content: "\2212";
}

.rule-block__more > summary:hover,
.rule-block__more > summary:focus-visible {
  color: var(--green-300);
}

.rule-block__body {
  margin-top: 18px;
}

.rule-block__body p {
  max-width: var(--measure);
  margin: 0 0 1.15em;
  font-size: 16px;
  line-height: 1.85;
  color: var(--silver-200);
}

.rule-block__body p:last-child {
  margin-bottom: 0;
}

.rule-block__body a {
  color: var(--green-300);
  text-decoration: none;
  border-bottom: 1px solid var(--green-500);
  transition: color var(--ease), border-color var(--ease);
}

.rule-block__body a:hover,
.rule-block__body a:focus-visible {
  color: var(--white-100);
  border-bottom-color: var(--white-100);
}

.usage-mail {
  font-family: var(--font-mono);
  font-size: 15px;
  letter-spacing: 0.01em;
  color: var(--green-300);
  overflow-wrap: anywhere;
}

/* ---------- 技术建议列表 ---------- */
.tech-list {
  margin: 20px 0 0;
  padding: 0 0 0 16px;
  list-style: none;
  border-left: 1px solid var(--line-700);
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.85;
  color: var(--silver-500);
}

.tech-list li {
  margin-bottom: 7px;
  overflow-wrap: anywhere;
}

.tech-list li:last-child {
  margin-bottom: 0;
}

.tech-list b {
  color: var(--silver-200);
  font-weight: 500;
}

/* ---------- 引用情形对照条 ---------- */
.usage-split {
  display: grid;
  margin-block: clamp(34px, 5vw, 56px);
  background: var(--ink-800);
  border: 1px solid var(--line-700);
}

.usage-split__col {
  padding: 26px 22px 30px;
}

.usage-split__col + .usage-split__col {
  border-top: 1px solid var(--line-700);
}

.usage-split__col--ok {
  border-bottom: 2px solid var(--green-500);
}

.usage-split__col--ask {
  border-bottom: 2px solid var(--orange-500);
}

.usage-split__title {
  margin: 0;
  font-size: 18px;
  font-weight: 700;
  line-height: 1.4;
  letter-spacing: -0.01em;
}

.usage-split__col--ok .usage-split__title {
  color: var(--green-300);
}

.usage-split__col--ask .usage-split__title {
  color: var(--amber-500);
}

.usage-split__list {
  margin: 16px 0 0;
  padding: 0;
  list-style: none;
}

.usage-split__list li {
  position: relative;
  margin-bottom: 11px;
  padding-left: 18px;
  font-size: 15px;
  line-height: 1.75;
  color: var(--silver-200);
}

.usage-split__list li:last-child {
  margin-bottom: 0;
}

.usage-split__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.78em;
  width: 8px;
  height: 1px;
  background: var(--silver-500);
}

.usage-split__col--ok .usage-split__list li::before {
  background: var(--green-500);
}

.usage-split__col--ask .usage-split__list li::before {
  background: var(--amber-500);
}

/* ---------- 收尾指引 ---------- */
.usage-next {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px 28px;
  margin-top: clamp(40px, 5.5vw, 64px);
  padding-top: clamp(24px, 3.6vw, 36px);
  border-top: 1px solid var(--line-700);
}

.usage-next__ask {
  max-width: 34em;
  margin: 0;
  font-size: 16px;
  line-height: 1.8;
  color: var(--silver-200);
}

.usage-next__acts {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* ---------- 左侧章节刻度 ---------- */
.page-disclaimer .rail {
  display: none;
}

@media (min-width: 1400px) {
  .page-disclaimer .rail {
    position: fixed;
    left: 22px;
    top: 50%;
    z-index: 5;
    display: flex;
    flex-direction: column;
    gap: 12px;
    max-width: 118px;
    transform: translateY(-50%);
  }

  .page-disclaimer .rail__tick {
    padding: 3px 0 3px 10px;
    border-left: 1px solid var(--line-700);
    font-size: 12px;
    line-height: 1.5;
    letter-spacing: 0.02em;
    color: var(--silver-500);
    text-decoration: none;
    transition: color var(--ease), border-color var(--ease);
  }

  .page-disclaimer .rail__tick:hover,
  .page-disclaimer .rail__tick:focus-visible,
  .page-disclaimer .rail__tick[data-active] {
    color: var(--green-300);
    border-left-color: var(--green-500);
  }
}

/* ---------- 宽屏栅格 ---------- */
@media (min-width: 900px) {
  .rule-block {
    grid-template-columns: 84px minmax(0, 1fr);
    column-gap: 0;
  }

  .rule-block__num {
    padding-top: 9px;
  }

  .usage-split {
    grid-template-columns: 1fr 1fr;
  }

  .usage-split__col + .usage-split__col {
    border-top: 0;
    border-left: 1px solid var(--line-700);
  }
}

@media (max-width: 640px) {
  .usage-cover img {
    aspect-ratio: 16 / 10;
  }

  .usage-next {
    align-items: flex-start;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-disclaimer .rule-block__more,
  .page-disclaimer .rule-block__more > summary,
  .page-disclaimer .usage-split__list li,
  .page-disclaimer .rail__tick,
  .page-disclaimer .rule-block__body a {
    transition: none;
  }
}