/* ================= page-disclaimer · 使用指引 ================= */

.page-disclaimer {
  --usage-tick: 18px;
  --usage-panel: rgba(18, 41, 74, 0.55);
  --usage-panel-soft: rgba(18, 41, 74, 0.32);
  --usage-gold-strong: rgba(242, 193, 78, 0.85);
  --usage-gold-mid: rgba(242, 193, 78, 0.5);
  --usage-gold-faint: rgba(242, 193, 78, 0.2);
}

/* ---------- 首屏框景 ---------- */

.page-disclaimer .usage-hero {
  padding: calc(var(--topbar-h) + 2.4rem) 0 2.2rem;
}

.page-disclaimer .usage-hero__frame {
  position: relative;
  margin-top: 1.5rem;
  padding: clamp(1.25rem, 3.6vw, 2.9rem);
  border: 1px solid var(--line);
  border-radius: var(--r-sm);
  background:
    linear-gradient(158deg, rgba(18, 41, 74, 0.82) 0%, rgba(8, 23, 38, 0.6) 66%),
    var(--navy-900);
  overflow: hidden;
}

.page-disclaimer .usage-hero__frame::before,
.page-disclaimer .usage-hero__frame::after {
  content: "";
  position: absolute;
  width: 30px;
  height: 30px;
  border: 1px solid var(--usage-gold-strong);
  pointer-events: none;
}

.page-disclaimer .usage-hero__frame::before {
  top: 10px;
  left: 10px;
  border-right: 0;
  border-bottom: 0;
}

.page-disclaimer .usage-hero__frame::after {
  right: 10px;
  bottom: 10px;
  border-top: 0;
  border-left: 0;
}

.page-disclaimer .usage-hero h1 {
  margin: 0.85rem 0 1rem;
  max-width: 22ch;
  font-family: var(--font-display);
  font-weight: 200;
  font-size: clamp(1.85rem, 6vw, 4.1rem);
  line-height: 1.08;
  letter-spacing: -0.02em;
  color: var(--ice);
}

.page-disclaimer .usage-hero__lead {
  margin: 0;
  max-width: 42ch;
  font-size: 0.95rem;
  line-height: 1.85;
  color: var(--mist);
}

.page-disclaimer .usage-hero__meta {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 2.2rem;
  margin: 1.8rem 0 0;
  padding: 1rem 0 0;
  border-top: 1px solid var(--line);
}

.page-disclaimer .usage-hero__meta li {
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
}

.page-disclaimer .usage-hero__meta-k {
  font-size: 0.7rem;
  letter-spacing: 0.16em;
  color: var(--mist);
}

.page-disclaimer .usage-hero__meta-v {
  font-size: 0.88rem;
  color: var(--ice);
}

/* ---------- 章节骨架与刻度尺 ---------- */

.page-disclaimer .usage-section {
  padding: clamp(2.4rem, 5.5vw, 4.6rem) 0;
  border-top: 1px solid rgba(44, 74, 114, 0.45);
}

.page-disclaimer .usage-section--tint {
  background: linear-gradient(180deg, rgba(18, 41, 74, 0.42) 0%, rgba(8, 23, 38, 0) 90%);
}

.page-disclaimer .usage-ruler {
  height: 9px;
  width: 100%;
  margin-bottom: 0.95rem;
  background-image: repeating-linear-gradient(
    to right,
    var(--usage-gold-strong) 0 1px,
    transparent 1px var(--usage-tick)
  );
  border-bottom: 1px solid var(--usage-gold-mid);
}

.page-disclaimer .usage-ruler--l1 {
  --usage-tick: 22px;
  max-width: 380px;
}

.page-disclaimer .usage-ruler--l2 {
  --usage-tick: 15px;
  max-width: 250px;
}

.page-disclaimer .usage-ruler--l3 {
  --usage-tick: 10px;
  max-width: 150px;
}

.page-disclaimer .usage-section h2 {
  margin: 0.35rem 0 0.75rem;
  max-width: 26ch;
  font-family: var(--font-display);
  font-weight: 300;
  font-size: clamp(1.4rem, 3.6vw, 2.35rem);
  line-height: 1.22;
  letter-spacing: -0.01em;
  color: var(--ice);
}

.page-disclaimer .usage-section__intro {
  margin: 0;
  max-width: 40ch;
  font-size: 0.92rem;
  line-height: 1.8;
  color: var(--mist);
}

/* ---------- 01 使用场景 ---------- */

.page-disclaimer .usage-scenes {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-top: 2rem;
}

.page-disclaimer .usage-scene {
  width: 100%;
  padding: 1rem 1.15rem 1.15rem;
  border: 1px solid var(--line);
  border-left-width: 3px;
  border-left-style: solid;
  border-radius: var(--r-sm);
  background: linear-gradient(90deg, var(--usage-gold-faint), var(--usage-panel) 62%, var(--usage-panel-soft));
}

.page-disclaimer .usage-scene--b {
  border-left-color: var(--usage-gold-mid);
  background: linear-gradient(90deg, rgba(242, 193, 78, 0.12), var(--usage-panel) 62%, var(--usage-panel-soft));
}

.page-disclaimer .usage-scene--c {
  border-left-color: var(--usage-gold-faint);
  background: linear-gradient(90deg, rgba(242, 193, 78, 0.07), var(--usage-panel) 62%, var(--usage-panel-soft));
}

.page-disclaimer .usage-scene--a {
  border-left-color: var(--gold);
}

.page-disclaimer .usage-scene__head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 0.5rem;
}

.page-disclaimer .usage-scene h3 {
  margin: 0;
  font-size: 1rem;
  font-weight: 600;
  color: var(--ice);
}

.page-disclaimer .usage-scene__tag {
  flex: none;
  padding: 0.16rem 0.55rem;
  border: 1px solid var(--usage-gold-mid);
  border-radius: 999px;
  font-size: 0.68rem;
  letter-spacing: 0.12em;
  color: var(--gold);
}

.page-disclaimer .usage-scene p {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.8;
  color: var(--mist);
}

.page-disclaimer .usage-figure {
  margin: 2rem 0 0;
}

.page-disclaimer .usage-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  border: 1px solid var(--line);
  border-radius: var(--r-sm);
}

/* ---------- 02 账号使用 ---------- */

.page-disclaimer .usage-account {
  display: grid;
  gap: 1rem;
  margin-top: 2rem;
}

.page-disclaimer .usage-account__card {
  padding: 1.15rem 1.2rem 1.3rem;
}

.page-disclaimer .usage-account__card h3 {
  margin: 0.45rem 0 0.6rem;
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--ice);
}

.page-disclaimer .usage-account__card p {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.8;
  color: var(--mist);
}

/* ---------- 03 引用写法 ---------- */

.page-disclaimer .usage-cite {
  display: grid;
  gap: 0.85rem;
  margin-top: 1.9rem;
}

.page-disclaimer .usage-cite__row {
  display: grid;
  gap: 0.4rem;
  padding: 0.9rem 1.1rem;
  border: 1px solid var(--line);
  border-radius: var(--r-sm);
  background: var(--usage-panel);
}

.page-disclaimer .usage-cite__label {
  font-size: 0.7rem;
  letter-spacing: 0.18em;
  color: var(--gold);
}

.page-disclaimer .usage-cite__sample {
  font-family: ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  font-size: 0.86rem;
  line-height: 1.7;
  color: var(--gold-soft);
  word-break: break-word;
}

.page-disclaimer .usage-cite__note {
  margin: 1.1rem 0 0;
  max-width: 46ch;
  font-size: 0.85rem;
  line-height: 1.8;
  color: var(--mist);
}

/* ---------- 04 变更通知时间线 ---------- */

.page-disclaimer .usage-timeline {
  list-style: none;
  margin: 2rem 0 0;
  padding: 0 0 0 1.4rem;
  border-left: 1px solid var(--line);
}

.page-disclaimer .usage-timeline__item {
  position: relative;
  padding-bottom: 1.7rem;
}

.page-disclaimer .usage-timeline__item:last-child {
  padding-bottom: 0;
}

.page-disclaimer .usage-timeline__item::before {
  content: "";
  position: absolute;
  top: 0.5rem;
  left: calc(-1.4rem - 4px);
  width: 9px;
  height: 9px;
  border-radius: 50%;
  border: 1px solid var(--gold);
  background: var(--navy-900);
}

.page-disclaimer .usage-timeline__when {
  display: block;
  margin-bottom: 0.3rem;
  font-size: 0.7rem;
  letter-spacing: 0.16em;
  color: var(--gold);
}

.page-disclaimer .usage-timeline h3 {
  margin: 0 0 0.4rem;
  font-size: 1rem;
  font-weight: 600;
  color: var(--ice);
}

.page-disclaimer .usage-timeline p {
  margin: 0;
  max-width: 44ch;
  font-size: 0.9rem;
  line-height: 1.8;
  color: var(--mist);
}

/* ---------- 05 求助入口 ---------- */

.page-disclaimer .usage-helps {
  display: grid;
  gap: 0.8rem;
  margin-top: 1.9rem;
}

.page-disclaimer .usage-help {
  display: block;
  padding: 1rem 1.15rem 1.1rem;
  border: 1px solid var(--line);
  border-radius: var(--r-sm);
  background: var(--usage-panel-soft);
  text-decoration: none;
  color: inherit;
  transition: border-color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.page-disclaimer .usage-help:hover,
.page-disclaimer .usage-help:focus-visible {
  border-color: var(--gold);
  background: rgba(242, 193, 78, 0.08);
}

.page-disclaimer .usage-help h3 {
  margin: 0 0 0.4rem;
  font-size: 0.98rem;
  font-weight: 600;
  color: var(--ice);
}

.page-disclaimer .usage-help p {
  margin: 0;
  font-size: 0.86rem;
  line-height: 1.75;
  color: var(--mist);
}

.page-disclaimer .usage-contact {
  margin-top: 2rem;
  padding: 1.1rem 1.2rem;
  border: 1px solid var(--line);
  border-left: 3px solid var(--gold);
  border-radius: var(--r-sm);
  background: linear-gradient(90deg, var(--usage-gold-faint), var(--usage-panel-soft) 70%);
}

.page-disclaimer .usage-contact__line {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.85;
  color: var(--ice);
}

.page-disclaimer .usage-contact__line a {
  color: var(--gold-soft);
  text-decoration: none;
  border-bottom: 1px solid var(--usage-gold-mid);
}

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

/* ---------- 断点 ---------- */

@media (min-width: 760px) {
  .page-disclaimer .usage-helps {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-disclaimer .usage-cite {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .page-disclaimer .usage-hero {
    padding: calc(var(--topbar-h) + 4.4rem) 0 3.6rem;
  }

  .page-disclaimer .usage-hero__lead {
    font-size: 1rem;
  }

  .page-disclaimer .usage-scene--a {
    width: 100%;
  }

  .page-disclaimer .usage-scene--b {
    width: 78%;
  }

  .page-disclaimer .usage-scene--c {
    width: 60%;
  }

  .page-disclaimer .usage-account {
    grid-template-columns: repeat(12, minmax(0, 1fr));
  }

  .page-disclaimer .usage-account__card:nth-child(1) {
    grid-column: 1 / span 7;
  }

  .page-disclaimer .usage-account__card:nth-child(2) {
    grid-column: 8 / span 5;
    margin-top: 2.2rem;
  }

  .page-disclaimer .usage-account__card:nth-child(3) {
    grid-column: 1 / span 6;
    margin-top: 0.6rem;
  }

  .page-disclaimer .usage-account__card:nth-child(4) {
    grid-column: 7 / span 6;
    margin-top: 2.8rem;
  }

  .page-disclaimer .usage-timeline {
    padding-left: 1.8rem;
  }

  .page-disclaimer .usage-timeline__item::before {
    left: calc(-1.8rem - 4px);
  }
}

@media (min-width: 1200px) {
  .page-disclaimer .usage-scene {
    padding: 1.15rem 1.5rem 1.3rem;
  }

  .page-disclaimer .usage-cite__sample {
    font-size: 0.9rem;
  }
}