/* ===== 使用说明 / page-disclaimer ===== */

.page-disclaimer {
  --u-rail: 232px;
  --u-line: rgba(39, 65, 95, 0.85);
  --u-panel: rgba(13, 27, 46, 0.86);
  position: relative;
  overflow-x: clip;
  padding-bottom: clamp(3rem, 7vw, 5.5rem);
  background:
    radial-gradient(760px 380px at 92% -8%, rgba(53, 240, 208, 0.10), transparent 60%),
    radial-gradient(620px 340px at 2% 6%, rgba(255, 138, 61, 0.07), transparent 62%);
}

/* ---- 首屏 ---- */
.page-disclaimer .usage-hero {
  position: relative;
  padding-block: clamp(2rem, 5vw, 3.6rem) clamp(2rem, 4.5vw, 3.2rem);
  border-bottom: 1px solid var(--u-line);
}

.page-disclaimer .usage-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(53, 240, 208, 0.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(53, 240, 208, 0.06) 1px, transparent 1px);
  background-size: 52px 52px;
  -webkit-mask-image: linear-gradient(180deg, #000 0%, transparent 82%);
  mask-image: linear-gradient(180deg, #000 0%, transparent 82%);
  pointer-events: none;
}

.page-disclaimer .usage-hero .container {
  position: relative;
  z-index: 1;
}

.page-disclaimer .usage-hero__grid {
  display: grid;
  gap: clamp(1.6rem, 4vw, 3rem);
  align-items: center;
  margin-top: clamp(1.2rem, 3vw, 2rem);
}

.page-disclaimer .usage-hero__copy h1 {
  margin: 0.5rem 0 0;
  font-family: var(--font-display);
  font-size: clamp(2rem, 5.4vw, 3.4rem);
  line-height: 1.06;
  letter-spacing: -0.005em;
  color: var(--c-text);
}

.page-disclaimer .usage-hero__copy h1::after {
  content: "";
  display: block;
  width: 76px;
  height: 3px;
  margin-top: 1rem;
  background: linear-gradient(90deg, var(--c-cyan), var(--c-orange));
}

.page-disclaimer .usage-hero__copy .lede {
  margin-top: 1.1rem;
  max-width: 56ch;
}

.page-disclaimer .usage-hero__media {
  margin: 0;
}

/* ---- 术语标签 ---- */
.page-disclaimer .usage-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 1.6rem 0 0;
  padding: 0;
  list-style: none;
}

.page-disclaimer .usage-tags a {
  display: inline-flex;
  align-items: baseline;
  gap: 0.45rem;
  padding: 0.42rem 0.7rem;
  border: 1px solid var(--u-line);
  border-radius: 2px;
  background: rgba(13, 27, 46, 0.72);
  color: var(--c-muted);
  font-size: 0.82rem;
  line-height: 1.2;
  text-decoration: none;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease), background-color 0.18s var(--ease);
}

.page-disclaimer .usage-tags a .index-number {
  color: var(--c-amber);
}

.page-disclaimer .usage-tags a:hover,
.page-disclaimer .usage-tags a:focus-visible {
  color: var(--c-text);
  border-color: var(--c-cyan);
  background: rgba(53, 240, 208, 0.09);
}

/* ---- 正文布局 ---- */
.page-disclaimer .usage-layout {
  display: grid;
  gap: clamp(1.5rem, 3.5vw, 2.75rem);
  align-items: start;
}

/* ---- 索引侧栏 ---- */
.page-disclaimer .usage-index {
  min-width: 0;
  padding: 1.05rem 1rem 1.15rem;
  border: 1px solid var(--u-line);
  background: var(--u-panel);
}

.page-disclaimer .usage-index__label {
  margin: 0 0 0.8rem;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--c-amber);
}

.page-disclaimer .usage-index__label::after {
  content: "";
  display: block;
  width: 28px;
  height: 2px;
  margin-top: 0.45rem;
  background: var(--c-amber);
  opacity: 0.75;
}

.page-disclaimer .usage-index__list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.15rem 0.5rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-disclaimer .usage-index__list a {
  display: flex;
  align-items: baseline;
  gap: 0.55rem;
  padding: 0.48rem 0.45rem;
  border-left: 2px solid transparent;
  color: var(--c-muted);
  font-size: 0.875rem;
  line-height: 1.4;
  text-decoration: none;
  transition: color 0.18s var(--ease), background-color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.page-disclaimer .usage-index__list a .index-number {
  flex: none;
  color: var(--c-cyan);
  font-size: 0.72rem;
}

.page-disclaimer .usage-index__list a:hover,
.page-disclaimer .usage-index__list a:focus-visible {
  color: var(--c-text);
  background: rgba(53, 240, 208, 0.07);
  border-left-color: var(--c-cyan);
}

.page-disclaimer .usage-index__hint {
  margin: 1rem 0 0;
  padding-top: 0.85rem;
  border-top: 1px dashed var(--u-line);
  font-size: 0.78rem;
  line-height: 1.65;
  color: var(--c-muted);
}

/* ---- 条款列表 ---- */
.page-disclaimer .usage-clauses {
  display: grid;
  gap: clamp(0.9rem, 2vw, 1.35rem);
  min-width: 0;
}

.page-disclaimer .usage-clause {
  min-width: 0;
  border: 1px solid var(--u-line);
  border-left: 3px solid rgba(53, 240, 208, 0.55);
  background: linear-gradient(180deg, rgba(13, 27, 46, 0.92), rgba(6, 16, 31, 0.94));
  scroll-margin-top: 6.5rem;
  transition: border-color 0.2s var(--ease), box-shadow 0.2s var(--ease);
}

.page-disclaimer .usage-clause:target {
  border-left-color: var(--c-orange);
  box-shadow: 0 0 0 1px rgba(255, 138, 61, 0.32);
}

.page-disclaimer .usage-clause__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1rem clamp(1rem, 2.4vw, 1.5rem);
  cursor: pointer;
  list-style: none;
  -webkit-tap-highlight-color: transparent;
  transition: background-color 0.18s var(--ease);
}

.page-disclaimer .usage-clause__head::-webkit-details-marker {
  display: none;
}

.page-disclaimer .usage-clause__head::marker {
  content: "";
}

.page-disclaimer .usage-clause__head::after {
  content: "+";
  flex: none;
  font-family: var(--font-mono);
  font-size: 1.15rem;
  line-height: 1;
  color: var(--c-cyan);
  transition: transform 0.22s var(--ease), color 0.22s var(--ease);
}

.page-disclaimer .usage-clause__head:hover {
  background: rgba(53, 240, 208, 0.045);
}

.page-disclaimer .usage-clause[open] > .usage-clause__head::after {
  transform: rotate(135deg);
  color: var(--c-orange);
}

.page-disclaimer .usage-clause__title {
  display: flex;
  align-items: baseline;
  gap: 0.7rem;
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(1.02rem, 1.6vw, 1.22rem);
  font-weight: 700;
  letter-spacing: 0.03em;
  color: var(--c-text);
}

.page-disclaimer .usage-clause__title .index-number {
  flex: none;
  font-size: 0.78rem;
  color: var(--c-cyan);
}

.page-disclaimer .usage-clause__body {
  padding: 1rem clamp(1rem, 2.4vw, 1.5rem) clamp(1.15rem, 2.2vw, 1.5rem);
  border-top: 1px solid rgba(39, 65, 95, 0.7);
}

.page-disclaimer .usage-clause__body p {
  max-width: 68ch;
  margin: 0 0 0.85rem;
  color: var(--c-muted);
  font-size: 0.975rem;
  line-height: 1.85;
}

.page-disclaimer .usage-clause__body p:last-child {
  margin-bottom: 0;
}

.page-disclaimer .usage-points {
  display: grid;
  gap: 0.55rem;
  max-width: 70ch;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-disclaimer .usage-points li {
  position: relative;
  padding-left: 1.2rem;
  color: var(--c-muted);
  font-size: 0.975rem;
  line-height: 1.8;
}

.page-disclaimer .usage-points li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 0.42rem;
  height: 0.42rem;
  background: var(--c-cyan);
  transform: rotate(45deg);
}

.page-disclaimer .usage-points li:nth-child(2n)::before {
  background: var(--c-orange);
}

/* ---- 页脚注 ---- */
.page-disclaimer .usage-footnote {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.6rem 1.1rem;
  margin: clamp(1.4rem, 3vw, 2.2rem) 0 0;
  padding-top: 1.1rem;
  border-top: 1px solid var(--u-line);
  color: var(--c-muted);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  line-height: 1.7;
}

.page-disclaimer .usage-footnote .tag {
  flex: none;
}

/* ---- 桌面栅格 ---- */
@media (min-width: 700px) {
  .page-disclaimer .usage-index__list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .page-disclaimer .usage-hero__grid {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
  }
}

@media (min-width: 1024px) {
  .page-disclaimer .usage-layout {
    grid-template-columns: var(--u-rail) minmax(0, 1fr);
  }

  .page-disclaimer .usage-index {
    position: sticky;
    top: 6rem;
  }

  .page-disclaimer .usage-index__list {
    grid-template-columns: minmax(0, 1fr);
  }
}

/* ---- 动效克制 ---- */
@media (prefers-reduced-motion: reduce) {
  .page-disclaimer .usage-tags a,
  .page-disclaimer .usage-index__list a,
  .page-disclaimer .usage-clause,
  .page-disclaimer .usage-clause__head,
  .page-disclaimer .usage-clause__head::after {
    transition: none;
  }
}