.page-disclaimer {
  --u-gap: 26px;
  --u-line-soft: rgba(57, 67, 90, .75);
  background: var(--ink);
  color: var(--cold);
  overflow-x: hidden;
}

.page-disclaimer .breadcrumbs {
  padding: 22px 0 0;
  color: var(--muted);
}

.page-disclaimer .breadcrumbs a {
  color: var(--cold);
  text-decoration: none;
  border-bottom: 1px solid var(--line);
}

.page-disclaimer .breadcrumbs a:hover,
.page-disclaimer .breadcrumbs a:focus-visible {
  color: var(--lime);
  border-bottom-color: var(--lime);
}

/* ---------- 首屏 ---------- */
.usage-hero {
  padding: 28px 0 34px;
}

.usage-hero__inner {
  display: grid;
  gap: 28px;
}

.usage-hero__lead h1 {
  margin: 14px 0 0;
  font-family: var(--font-head);
  font-weight: 900;
  letter-spacing: -.025em;
  line-height: 1.05;
  font-size: clamp(30px, 7.2vw, 62px);
  color: var(--paper);
}

.usage-hero__sub {
  margin: 16px 0 0;
  max-width: 38em;
  font-size: 16px;
  line-height: 1.78;
  color: var(--cold);
}

.usage-hero__index {
  border: var(--bw) solid var(--line);
  background: var(--deep);
  box-shadow: var(--shadow-card);
  padding: 16px 16px 18px;
}

.usage-hero__index-title {
  margin: 0 0 10px;
  font-size: 12px;
  letter-spacing: .18em;
  color: var(--lime);
}

.usage-index {
  list-style: none;
  margin: 0;
  padding: 0;
}

.usage-index a {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 10px 6px;
  font-size: 14px;
  line-height: 1.5;
  color: var(--cold);
  text-decoration: none;
  border-bottom: 1px solid var(--u-line-soft);
  transition: color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.usage-index li:last-child a {
  border-bottom: 0;
}

.usage-index a .mono {
  flex: none;
  font-size: 12px;
  color: var(--lime);
}

.usage-index a:hover,
.usage-index a:focus-visible {
  color: var(--lime);
  background-color: rgba(168, 255, 46, .07);
}

/* ---------- 头部配图 ---------- */
.usage-figure {
  margin: var(--u-gap) 0 0;
}

.usage-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  background: var(--deep);
  border: var(--bw) solid var(--line);
}

.usage-figure__cap {
  margin: 10px 0 0;
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
}

/* ---------- 条目清单 ---------- */
.usage-list {
  margin: 36px 0 0;
  display: grid;
  gap: 16px;
}

.usage-entry {
  border: var(--bw) solid var(--line);
  background: var(--deep);
  scroll-margin-top: 84px;
  transition: border-color var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

.usage-entry[open] {
  border-color: var(--lime-deep);
  box-shadow: 6px 6px 0 rgba(78, 143, 0, .3);
}

.usage-entry__head {
  display: flex;
  align-items: center;
  gap: 13px;
  padding: 15px 16px;
  cursor: pointer;
  list-style: none;
  background: linear-gradient(90deg, rgba(168, 255, 46, .08), transparent 62%);
  border-left: 0 solid var(--lime);
}

.usage-entry__head::-webkit-details-marker {
  display: none;
}

.usage-entry__head:focus-visible {
  outline: 2px solid var(--lime);
  outline-offset: -4px;
}

.usage-entry__num {
  flex: none;
  font-size: 20px;
  font-weight: 700;
  line-height: 1;
  color: var(--lime);
}

.usage-entry__title {
  flex: 1;
  margin: 0;
  font-family: var(--font-head);
  font-weight: 900;
  letter-spacing: -.015em;
  line-height: 1.3;
  font-size: clamp(17px, 4.4vw, 24px);
  color: var(--paper);
}

.usage-entry__toggle {
  position: relative;
  flex: none;
  width: 16px;
  height: 16px;
}

.usage-entry__toggle::before,
.usage-entry__toggle::after {
  content: "";
  position: absolute;
  left: 0;
  top: 7px;
  width: 16px;
  height: 2px;
  background: var(--lime);
}

.usage-entry__toggle::after {
  transform: rotate(90deg);
  transition: transform var(--dur) var(--ease), opacity var(--dur) var(--ease);
}

.usage-entry[open] .usage-entry__toggle::after {
  transform: rotate(0deg);
  opacity: 0;
}

.usage-entry__body {
  padding: 4px 16px 22px;
  border-top: 1px solid var(--line);
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--cold);
}

.usage-entry__body > p {
  margin: 14px 0 0;
  max-width: 38em;
}

/* ---------- 场景标签条 ---------- */
.usage-tags {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 16px 0 0;
  padding: 0;
}

.usage-tags__item {
  padding: 7px 13px;
  font-size: 13px;
  letter-spacing: .02em;
  color: var(--lime);
  background: rgba(168, 255, 46, .07);
  border: 2px solid var(--lime-deep);
}

/* ---------- 署名示例 ---------- */
.usage-code {
  margin: 16px 0 0;
  padding: 15px 16px;
  background: var(--ink);
  border: 1px solid var(--line);
  border-left: 4px solid var(--lime);
  overflow-x: auto;
  font-family: var(--font-num);
  font-size: 13px;
  line-height: 1.95;
  color: var(--lime);
  white-space: pre;
}

/* ---------- 接口表格 ---------- */
.usage-table-wrap {
  margin: 16px 0 0;
  border: var(--bw) solid var(--line);
  overflow-x: auto;
}

.usage-table {
  width: 100%;
  min-width: 440px;
  border-collapse: collapse;
  font-size: 14px;
}

.usage-table caption {
  caption-side: top;
  text-align: left;
  padding: 11px 14px;
  background: var(--ink);
  color: var(--muted);
  font-family: var(--font-num);
  font-size: 12px;
  letter-spacing: .12em;
}

.usage-table th,
.usage-table td {
  text-align: left;
  padding: 12px 14px;
  border-top: 1px solid var(--line);
  vertical-align: top;
  line-height: 1.68;
}

.usage-table thead th {
  background: var(--ink);
  color: var(--lime);
  font-size: 12.5px;
  letter-spacing: .1em;
  font-weight: 700;
}

.usage-table tbody th {
  white-space: nowrap;
  font-weight: 700;
  color: var(--paper);
  background: rgba(31, 79, 168, .16);
}

.usage-table tbody td {
  color: var(--cold);
}

.usage-table tbody tr:hover th,
.usage-table tbody tr:hover td {
  background-color: rgba(168, 255, 46, .07);
}

/* ---------- 客户端提示列表 ---------- */
.usage-notes {
  list-style: none;
  margin: 16px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.usage-notes li {
  padding: 12px 14px;
  border-left: 3px solid var(--steel);
  background: rgba(31, 79, 168, .1);
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--cold);
}

.usage-notes strong {
  display: block;
  margin-bottom: 3px;
  font-size: 13px;
  letter-spacing: .05em;
  color: var(--paper);
}

/* ---------- 标注示例行 ---------- */
.usage-spec {
  margin: 16px 0 0;
  padding: 13px 15px;
  border: 1px dashed var(--lime-deep);
  background: rgba(168, 255, 46, .06);
  font-size: 13px;
  line-height: 1.8;
  color: var(--lime);
  overflow-wrap: anywhere;
}

/* ---------- 底部延伸入口 ---------- */
.usage-foot {
  margin-top: 42px;
  border-top: 10px solid var(--lime);
  background: var(--deep);
}

.usage-foot__inner {
  padding: 24px 0 34px;
  display: grid;
  gap: 20px;
}

.usage-foot__text {
  margin: 0;
  max-width: 40em;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--cold);
}

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

/* ---------- 桌面 ---------- */
@media (min-width: 860px) {
  .usage-hero {
    padding: 44px 0 50px;
  }

  .usage-hero__inner {
    grid-template-columns: minmax(0, 1.42fr) minmax(272px, .78fr);
    gap: 44px;
    align-items: start;
  }

  .usage-hero__index {
    padding: 20px 20px 22px;
  }

  .usage-list {
    margin-top: 50px;
    gap: 22px;
  }

  .usage-entry__head {
    padding: 20px 24px;
    gap: 20px;
  }

  .usage-entry__num {
    font-size: 27px;
  }

  .usage-entry__body {
    padding: 6px 24px 28px;
  }

  .usage-table {
    font-size: 14.5px;
  }

  .usage-foot {
    margin-top: 56px;
  }

  .usage-foot__inner {
    grid-template-columns: minmax(0, 1.25fr) auto;
    align-items: center;
    gap: 34px;
    padding: 28px 0 38px;
  }

  .usage-foot__actions {
    justify-content: flex-end;
  }
}

@media (min-width: 1180px) {
  .usage-hero__index {
    position: sticky;
    top: 24px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .usage-entry__toggle::after,
  .usage-index a,
  .usage-entry {
    transition: none;
  }
}