/* ==========================================================================
   25_cover.css - Cover-specific styles
   Restored from the last clean cover implementation and isolated from
   general custom styles so the index cover can evolve independently.
   ========================================================================== */

/* --------------------------------------------------------------------------
   COVER - fully frozen (no rem/vw/clamp)
   -------------------------------------------------------------------------- */

.md-typeset .admonition.cover {
  --cover-w: 500px;
  --cover-h: 790px;
  --cover-w-sm: 480px;
  --cover-h-sm: 620px;
  --cover-radius: 18px;
  --cover-radius-sm: 14px;
  --cover-gap-md: 10px;
  --cover-gap-sm: 6px;
  --cover-pad-top: 36px;
  --cover-pad-x: 48px;
  --cover-pad-bottom: 48px;
  --cover-gap-md-sm: 8px;
  --cover-gap-sm-sm: 5px;
  --cover-pad-top-sm: 22px;
  --cover-pad-x-sm: 38px;
  --cover-pad-bottom-sm: 20px;
  --cover-font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", sans-serif;
  --cover-base-size: 16px;
  --cover-base-size-sm: 13px;
  --cover-base-lh: 1.2;
  --cover-bg: #243041;
  --cover-fg: #eaf1f8;
  --cover-border: rgba(255, 255, 255, 0.08);
  --cover-shadow: 0 16px 50px rgba(0, 0, 0, 0.32);
  --cover-h1-size: 2.8em;
  --cover-h1-lh: 1.1;
  --cover-subtitle-size: 1.3em;
  --cover-subtitle-lh: 1.35;
  --cover-label-size: 0.75em;
  --cover-label-lh: 1;
  --cover-name-size: 1em;
  --cover-name-lh: 1.35;
  --cover-footer-size: 0.85em;
  --cover-footer-lh: 1.25;
  --cover-meta-gap: 6px;
  --cover-meta-gap-sm: 2px;
  box-sizing: border-box;
  width: var(--cover-w);
  height: var(--cover-h);
  margin-inline: auto;
  margin-bottom: 4rem;
  background: var(--cover-bg);
  color: var(--cover-fg);
  border: 1px solid var(--cover-border);
  border-radius: var(--cover-radius);
  box-shadow: var(--cover-shadow);
  padding: var(--cover-pad-top) var(--cover-pad-x) var(--cover-pad-bottom) var(--cover-pad-x);
  display: flex;
  flex-direction: column;
  gap: var(--cover-gap-md);
  font-family: var(--cover-font-family);
  font-size: var(--cover-base-size);
  line-height: var(--cover-base-lh);
}

.md-typeset .admonition.cover::before {
  display: none;
}

.md-typeset .admonition.cover > .admonition-title {
  display: none;
}

.md-typeset .admonition.cover > *:not(.admonition-title) {
  margin: 0;
}

.md-typeset .admonition.cover .cover-title-block {
  display: flex;
  flex-direction: column;
  gap: var(--cover-gap-sm);
}

.md-typeset .admonition.cover .cover-title-block h1 {
  font-family: var(--cover-font-family);
  font-size: var(--cover-h1-size);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: var(--cover-h1-lh);
  color: var(--cover-fg);
  margin: 0;
  padding: 0;
  max-width: 15ch;
}

.md-typeset .admonition.cover .cover-title-block h1 .cover-title-accent {
  color: var(--book-title-accent);
  font-weight: 700;
}

.md-typeset .admonition.cover .cover-subtitle {
  font-family: var(--cover-font-family);
  font-size: var(--cover-subtitle-size);
  font-weight: 500;
  letter-spacing: 0.005em;
  line-height: var(--cover-subtitle-lh);
  color: var(--cover-fg);
  opacity: 0.8;
  margin: 0;
}

.md-typeset .admonition.cover .cover-coordination,
.md-typeset .admonition.cover .cover-authors {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.md-typeset .admonition.cover .cover-label {
  font-family: var(--cover-font-family);
  font-size: var(--cover-label-size);
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  line-height: var(--cover-label-lh);
  color: var(--cover-fg);
  opacity: 0.6;
  margin: 0;
}

.md-typeset .admonition.cover .cover-coordination .cover-label,
.md-typeset .admonition.cover .cover-authors .cover-label {
  margin: 0 0 var(--cover-meta-gap) 0;
}

.md-typeset .admonition.cover .cover-name {
  font-family: var(--cover-font-family);
  font-size: var(--cover-name-size);
  font-weight: 500;
  letter-spacing: 0.01em;
  line-height: var(--cover-name-lh);
  color: var(--cover-fg);
  opacity: 0.9;
  margin: 0;
}

.md-typeset .admonition.cover .cover-authors-list {
  display: flex;
  flex-wrap: wrap;
  column-gap: 10px;
  row-gap: 6px;
  align-items: flex-start;
  margin: 0;
  padding: 0;
  max-width: 32ch;
}

.md-typeset .admonition.cover .cover-authors-list .pair {
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
  white-space: nowrap;
}

.md-typeset .admonition.cover .cover-authors-list .name {
  font-family: var(--cover-font-family);
  font-size: var(--cover-name-size);
  font-weight: 450;
  letter-spacing: 0.005em;
  line-height: var(--cover-name-lh);
  color: var(--cover-fg);
  opacity: 0.9;
  margin: 0;
  white-space: nowrap;
}

.md-typeset .admonition.cover .cover-authors-list .separator {
  font-family: var(--cover-font-family);
  font-size: var(--cover-name-size);
  line-height: var(--cover-name-lh);
  color: var(--cover-fg);
  opacity: 0.6;
  margin: 0;
}

.md-typeset .admonition.cover .cover-footer {
  font-family: var(--cover-font-family);
  font-size: var(--cover-footer-size);
  line-height: var(--cover-footer-lh);
  color: var(--cover-fg);
  margin-top: auto;
  padding-top: 14px;
  border-top: 0.5px solid #7ab0e8;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.md-typeset .admonition.cover .cover-footer > div,
.md-typeset .admonition.cover .cover-footer-year {
  margin: 0;
  padding: 0;
}

.md-typeset .admonition.cover .cover-footer-top {
  display: flex;
  align-items: baseline;
  margin: 0;
  padding: 0;
}

.md-typeset .admonition.cover .cover-footer-top .separator {
  display: inline-block;
  margin: 0 6px;
  opacity: 0.6;
  line-height: 1;
  color: var(--cover-fg);
}

.md-typeset .admonition.cover .cover-footer a {
  color: #7ab0e8;
  font-weight: 500;
  text-decoration: none;
}

@media (max-width: 560px) {
  .md-typeset .admonition.cover {
    --cover-h1-size: 2.5em;
    --cover-meta-gap: var(--cover-meta-gap-sm);
    width: min(100%, var(--cover-w-sm));
    max-width: var(--cover-w-sm);
    height: var(--cover-h-sm);
    border-radius: var(--cover-radius-sm);
    padding: var(--cover-pad-top-sm) var(--cover-pad-x-sm) var(--cover-pad-bottom-sm) var(--cover-pad-x-sm);
    gap: var(--cover-gap-md-sm);
    font-size: var(--cover-base-size-sm);
  }

  .md-typeset .admonition.cover .cover-title-block {
    gap: var(--cover-gap-sm-sm);
  }

  .md-typeset .admonition.cover .cover-title-block h1 {
    max-width: 16ch;
  }

  .md-typeset .admonition.cover .cover-coordination,
  .md-typeset .admonition.cover .cover-authors {
    gap: var(--cover-gap-sm-sm);
  }

  .md-typeset .admonition.cover .cover-authors-list {
    column-gap: 8px;
    row-gap: 5px;
  }

  .md-typeset .admonition.cover .cover-authors-list .pair {
    gap: 5px;
  }

  .md-typeset .admonition.cover .cover-footer {
    padding-top: 11px;
    gap: 3px;
  }

  .md-typeset .admonition.cover .cover-footer-top .separator {
    margin: 0 5px;
  }

  .md-typeset .admonition.cover .cover-footer a {
    text-underline-offset: 2px;
  }
}

body[data-md-color-scheme="slate"] .md-typeset .admonition.cover {
  background: #243041;
  border-color: rgba(255, 255, 255, 0.08);
  color: #eaf1f8;
}

body[data-md-color-scheme="slate"] .md-typeset .admonition.cover .cover-title-block h1,
body[data-md-color-scheme="slate"] .md-typeset .admonition.cover .cover-subtitle {
  color: #eaf1f8;
}

body[data-md-color-scheme="slate"] .md-typeset .admonition.cover .cover-title-accent {
  color: #7ab0e8;
}

body[data-md-color-scheme="slate"] .md-typeset .admonition.cover .cover-label {
  color: #eaf1f8;
  opacity: 0.55;
}

body[data-md-color-scheme="slate"] .md-typeset .admonition.cover .cover-name {
  color: #eaf1f8;
  opacity: 0.9;
}

body[data-md-color-scheme="slate"] .md-typeset .admonition.cover .cover-authors-list .name {
  color: #eaf1f8;
  opacity: 0.8;
}

body[data-md-color-scheme="slate"] .md-typeset .admonition.cover .cover-authors-list .separator {
  color: #eaf1f8;
  opacity: 0.55;
}

body[data-md-color-scheme="slate"] .md-typeset .admonition.cover .cover-footer {
  color: #eaf1f8;
  opacity: 0.65;
  border-top-color: rgba(255, 255, 255, 0.06);
}

body[data-md-color-scheme="slate"] .md-typeset .admonition.cover .cover-footer a {
  color: inherit;
  opacity: inherit;
  text-decoration: underline;
  text-decoration-color: #7ab0e8;
}

/* --------------------------------------------------------------------------
   COVER Stage (index)
   -------------------------------------------------------------------------- */

body.has-cover-scroll .md-typeset .cover-stage {
  --cover-stage-scroll: 22vh;
  --cover-stage-coverh: 620px;
  position: relative;
  height: calc(var(--cover-stage-coverh) + var(--cover-stage-scroll));
  margin-bottom: calc(-1 * var(--cover-stage-scroll));
}

body.has-cover-scroll .md-typeset .cover-stage .admonition.cover {
  position: sticky;
  top: 88px;
  z-index: 0;
  opacity: var(--cover-opacity, 1);
  transform: none;
  transition: none;
  will-change: opacity;
}

body.has-cover-scroll .md-typeset .cover-stage ~ * {
  position: relative;
  z-index: 1;
}

body.has-cover-scroll .md-typeset .cover-stage + * {
  margin-top: -240px;
  padding-top: 240px;
}

@media (max-width: 768px) {
  body.has-cover-scroll .md-typeset .cover-stage {
    --cover-stage-scroll: 22vh;
    --cover-stage-coverh: 520px;
    height: calc(var(--cover-stage-coverh) + var(--cover-stage-scroll));
    margin-bottom: calc(-1 * var(--cover-stage-scroll));
  }

  body.has-cover-scroll .md-typeset .cover-stage .admonition.cover {
    top: 72px;
  }

  body.has-cover-scroll .md-typeset .cover-stage + * {
    margin-top: -160px;
    padding-top: 160px;
  }
}

@media (prefers-reduced-motion: reduce) {
  body.has-cover-scroll .md-typeset .cover-stage .admonition.cover {
    transform: none !important;
    opacity: 1 !important;
    transition: none !important;
  }
}