.page-disclaimer {
  --usage-rule: rgba(243, 240, 233, .10);
  --usage-rule-strong: rgba(243, 240, 233, .18);
  --usage-measure: 68ch;
  background: var(--ink);
  color: var(--text);
}

/* ---------- 页首 ---------- */

.page-disclaimer .usage-hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  padding-block: clamp(96px, 16vh, 176px) clamp(36px, 5vw, 60px);
  background:
    radial-gradient(112% 78% at 6% 0%, rgba(111, 91, 255, .26), transparent 58%),
    radial-gradient(86% 70% at 94% 4%, rgba(47, 230, 230, .15), transparent 62%),
    linear-gradient(180deg, var(--ink) 0%, var(--ink-2) 100%);
  border-bottom: 1px solid var(--line-soft);
}

.page-disclaimer .usage-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background-image: repeating-linear-gradient(
    90deg,
    rgba(243, 240, 233, .055) 0 1px,
    transparent 1px 104px
  );
  -webkit-mask-image: linear-gradient(180deg, transparent 0%, #000 26%, transparent 94%);
  mask-image: linear-gradient(180deg, transparent 0%, #000 26%, transparent 94%);
}

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

.page-disclaimer .usage-hero .breadcrumb {
  margin-bottom: clamp(24px, 4vw, 40px);
}

.page-disclaimer .usage-hero h1 {
  font-family: var(--font-serif);
  font-size: var(--step-4);
  font-weight: 600;
  line-height: 1.08;
  letter-spacing: -.012em;
  color: var(--bone);
  margin: 12px 0 0;
  max-width: 18ch;
}

.page-disclaimer .usage-hero__lead {
  margin: 20px 0 0;
  max-width: 60ch;
  font-size: var(--step-1);
  line-height: 1.7;
  color: var(--text-soft);
}

.page-disclaimer .usage-hero__media {
  position: relative;
  margin: clamp(30px, 4.5vw, 52px) 0 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--ink-3);
}

.page-disclaimer .usage-hero__media::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(180deg, transparent 52%, rgba(7, 11, 20, .6) 100%);
}

.page-disclaimer .usage-hero__media img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  object-position: center;
}

/* ---------- 主体两栏 ---------- */

.page-disclaimer .usage-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 4vw, 56px);
  padding-block: clamp(32px, 5vw, 64px) clamp(56px, 8vw, 104px);
}

/* ---------- 索引 ---------- */

.page-disclaimer .usage-toc__label {
  font-family: var(--font-mono);
  font-size: var(--step--2);
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--text-dim);
  margin: 0 0 12px;
}

.page-disclaimer .usage-toc__list {
  list-style: none;
  margin: 0;
  padding: 0 0 4px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
}

.page-disclaimer .usage-toc__link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  white-space: nowrap;
  padding: 9px 14px;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-family: var(--font-ui);
  font-size: var(--step--1);
  letter-spacing: .02em;
  color: var(--text-soft);
  text-decoration: none;
  background: var(--ink-2);
  transition: color .22s var(--ease), border-color .22s var(--ease), background-color .22s var(--ease);
}

.page-disclaimer .usage-toc__link:hover,
.page-disclaimer .usage-toc__link:focus-visible {
  color: var(--bone);
  border-color: var(--cyan);
  background: rgba(47, 230, 230, .09);
}

.page-disclaimer .usage-toc__num {
  font-family: var(--font-mono);
  font-size: var(--step--2);
  color: var(--cyan);
  letter-spacing: .06em;
}

/* ---------- 条款 ---------- */

.page-disclaimer .usage-body {
  min-width: 0;
}

.page-disclaimer .usage-clause {
  padding-block: clamp(26px, 3.6vw, 42px);
  border-top: 1px solid var(--usage-rule);
  scroll-margin-top: calc(var(--header-offset) + 24px);
}

.page-disclaimer .usage-clause:first-child {
  border-top-color: var(--usage-rule-strong);
  padding-top: 0;
}

.page-disclaimer .usage-clause__head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 6px 16px;
  align-items: baseline;
  margin-bottom: 16px;
}

.page-disclaimer .usage-clause__num {
  font-family: var(--font-mono);
  font-size: var(--step-0);
  font-weight: 500;
  letter-spacing: .08em;
  color: var(--lime);
  line-height: 1.2;
}

.page-disclaimer .usage-clause__title {
  margin: 0;
  font-family: var(--font-serif);
  font-size: var(--step-2);
  font-weight: 600;
  line-height: 1.26;
  color: var(--bone);
}

.page-disclaimer .usage-clause__body > p {
  margin: 0 0 14px;
  max-width: var(--usage-measure);
  font-size: var(--step-0);
  line-height: 1.78;
  color: var(--text-soft);
}

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

.page-disclaimer .usage-clause__body a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(47, 230, 230, .34);
  transition: border-color .2s var(--ease), color .2s var(--ease);
}

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

.page-disclaimer .usage-clause__body strong {
  color: var(--bone);
  font-weight: 600;
}

.page-disclaimer .usage-list {
  list-style: none;
  margin: 18px 0 0;
  padding: 0;
  display: grid;
  gap: 11px;
  max-width: var(--usage-measure);
}

.page-disclaimer .usage-list li {
  position: relative;
  padding-left: 24px;
  font-size: var(--step-0);
  line-height: 1.72;
  color: var(--text-soft);
}

.page-disclaimer .usage-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .68em;
  width: 10px;
  height: 2px;
  background: var(--grass);
}

.page-disclaimer .usage-list li:nth-child(2)::before {
  background: var(--violet);
}

.page-disclaimer .usage-list li:nth-child(3)::before {
  background: var(--clay);
}

.page-disclaimer .usage-note {
  margin-top: 18px !important;
  max-width: var(--usage-measure);
  padding: 14px 18px;
  border-left: 2px solid var(--cyan);
  border-radius: 0 var(--radius) var(--radius) 0;
  background: rgba(47, 230, 230, .07);
  font-size: var(--step--1);
  line-height: 1.75;
  color: var(--text-soft);
}

/* ---------- 折叠 ---------- */

.page-disclaimer .usage-fold {
  margin-top: 22px;
  max-width: var(--usage-measure);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--ink-2);
  transition: border-color .22s var(--ease);
}

.page-disclaimer .usage-fold:hover {
  border-color: var(--usage-rule-strong);
}

.page-disclaimer .usage-fold summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 15px 18px;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-ui);
  font-size: var(--step--1);
  letter-spacing: .04em;
  color: var(--bone);
}

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

.page-disclaimer .usage-fold summary::after {
  content: "+";
  flex: none;
  font-family: var(--font-mono);
  font-size: 1.05rem;
  line-height: 1;
  color: var(--cyan);
}

.page-disclaimer .usage-fold[open] summary::after {
  content: "−";
}

.page-disclaimer .usage-fold summary:focus-visible {
  outline: 2px solid var(--violet);
  outline-offset: 2px;
}

.page-disclaimer .usage-fold__body {
  padding: 0 18px 18px;
  border-top: 1px solid var(--line-soft);
  margin-top: 2px;
  padding-top: 14px;
  color: var(--text-soft);
  font-size: var(--step--1);
  line-height: 1.75;
}

.page-disclaimer .usage-fold__body p {
  margin: 0 0 10px;
}

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

/* ---------- 联系方式 ---------- */

.page-disclaimer .usage-contact {
  display: grid;
  gap: 0;
  margin: 20px 0 18px;
  max-width: var(--usage-measure);
}

.page-disclaimer .usage-contact__row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 14px;
  padding: 13px 0;
  border-bottom: 1px dashed var(--line);
  font-size: var(--step--1);
}

.page-disclaimer .usage-contact__key {
  flex: none;
  min-width: 56px;
  font-family: var(--font-mono);
  font-size: var(--step--2);
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--text-dim);
}

.page-disclaimer .usage-contact__val {
  color: var(--bone);
  word-break: break-word;
  line-height: 1.6;
  text-decoration: none;
}

.page-disclaimer a.usage-contact__val {
  border-bottom: 1px solid transparent;
  transition: color .2s var(--ease), border-color .2s var(--ease);
}

.page-disclaimer a.usage-contact__val:hover,
.page-disclaimer a.usage-contact__val:focus-visible {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

.page-disclaimer .usage-contact .copy-btn {
  flex: none;
  margin-left: auto;
}

/* ---------- 页脚条 ---------- */

.page-disclaimer .usage-footbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  margin-top: clamp(32px, 4.5vw, 56px);
  padding-top: 22px;
  border-top: 1px solid var(--usage-rule-strong);
}

.page-disclaimer .usage-footbar__meta {
  margin: 0;
  font-size: var(--step--1);
  line-height: 1.7;
  color: var(--text-dim);
}

.page-disclaimer .usage-footbar__meta a {
  color: var(--text-soft);
  text-decoration: none;
  border-bottom: 1px solid rgba(243, 240, 233, .28);
  transition: color .2s var(--ease), border-color .2s var(--ease);
}

.page-disclaimer .usage-footbar__meta a:hover,
.page-disclaimer .usage-footbar__meta a:focus-visible {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

/* ---------- 桌面布局 ---------- */

@media (min-width: 900px) {
  .page-disclaimer .usage-layout {
    grid-template-columns: minmax(180px, 232px) minmax(0, 1fr);
    align-items: start;
  }

  .page-disclaimer .usage-toc {
    position: sticky;
    top: calc(var(--header-offset) + 28px);
    align-self: start;
  }

  .page-disclaimer .usage-toc__list {
    flex-direction: column;
    gap: 0;
    overflow: visible;
    border-left: 1px solid var(--line);
  }

  .page-disclaimer .usage-toc__link {
    border: 0;
    border-left: 2px solid transparent;
    border-radius: 0;
    background: transparent;
    padding: 9px 12px;
    margin-left: -1px;
    white-space: normal;
    line-height: 1.5;
  }

  .page-disclaimer .usage-toc__link:hover,
  .page-disclaimer .usage-toc__link:focus-visible {
    border-left-color: var(--cyan);
    background: rgba(47, 230, 230, .06);
  }

  .page-disclaimer .usage-clause__head {
    gap: 8px 22px;
  }

  .page-disclaimer .usage-hero h1 {
    max-width: 16ch;
  }
}

@media (min-width: 1200px) {
  .page-disclaimer .usage-layout {
    grid-template-columns: minmax(200px, 260px) minmax(0, 1fr);
  }
}

/* ---------- 降低动态效果 ---------- */

@media (prefers-reduced-motion: reduce) {
  .page-disclaimer .usage-toc__link,
  .page-disclaimer .usage-fold,
  .page-disclaimer .usage-clause__body a,
  .page-disclaimer .usage-contact__val {
    transition: none;
  }
}

/* ---------- 打印 ---------- */

@media print {
  .page-disclaimer {
    background: #fff;
    color: #111;
  }

  .page-disclaimer .usage-hero {
    background: none;
    border-bottom: 1px solid #ccc;
    padding-block: 0 16px;
  }

  .page-disclaimer .usage-hero::before {
    display: none;
  }

  .page-disclaimer .usage-hero h1,
  .page-disclaimer .usage-clause__title,
  .page-disclaimer .usage-clause__body strong {
    color: #111;
  }

  .page-disclaimer .usage-hero__media {
    display: none;
  }

  .page-disclaimer .usage-toc,
  .page-disclaimer .usage-footbar {
    display: none;
  }

  .page-disclaimer .usage-layout {
    grid-template-columns: minmax(0, 1fr);
    padding-block: 16px 0;
  }

  .page-disclaimer .usage-clause__num {
    color: #444;
  }

  .page-disclaimer .usage-clause__body > p,
  .page-disclaimer .usage-list li,
  .page-disclaimer .usage-contact__val {
    color: #222;
  }

  .page-disclaimer .usage-fold {
    border-color: #ccc;
    background: none;
  }

  .page-disclaimer .usage-fold__body {
    display: block;
  }
}