/* ===========================================================================
   Exercise admonitions — Tufte minimal style
   Three difficulty levels: exercise-easy, exercise-intermediate, exercise-hard.
   No borders, no backgrounds — just typography and whitespace.
   =========================================================================== */

/* --- Counter ---------------------------------------------------------------- */
.md-content {
  counter-reset: exercise;
}

.md-typeset .admonition.exercise-easy,
.md-typeset .admonition.exercise-intermediate,
.md-typeset .admonition.exercise-hard,
.md-typeset details.exercise-easy,
.md-typeset details.exercise-intermediate,
.md-typeset details.exercise-hard {
  counter-increment: exercise;
}

/* --- Base: strip admonition chrome ----------------------------------------- */
.md-typeset .admonition.exercise-easy,
.md-typeset .admonition.exercise-intermediate,
.md-typeset .admonition.exercise-hard,
.md-typeset details.exercise-easy,
.md-typeset details.exercise-intermediate,
.md-typeset details.exercise-hard {
  border: none;
  background: transparent;
  box-shadow: none;
  padding: 0;
  margin: 2.5rem 0;
  overflow: visible;
  position: relative;
  font-size: inherit;
}

/* --- Centered dot separator above ------------------------------------------ */
.md-typeset .admonition.exercise-easy::before,
.md-typeset .admonition.exercise-intermediate::before,
.md-typeset .admonition.exercise-hard::before,
.md-typeset details.exercise-easy::before,
.md-typeset details.exercise-intermediate::before,
.md-typeset details.exercise-hard::before {
  content: "· · ·";
  display: block;
  text-align: center;
  color: var(--rb-gruvbox-muted);
  font-size: 1.2em;
  letter-spacing: 0.3em;
  margin-bottom: 1.5rem;
}

/* --- Title: reset Material defaults ---------------------------------------- */
.md-typeset .exercise-easy > .admonition-title,
.md-typeset .exercise-easy > summary,
.md-typeset .exercise-intermediate > .admonition-title,
.md-typeset .exercise-intermediate > summary,
.md-typeset .exercise-hard > .admonition-title,
.md-typeset .exercise-hard > summary {
  background: transparent;
  border: none;
  padding: 0 0 0.4rem 0;
  font-weight: 400;
  font-style: italic;
  font-size: var(--rb-h3-size);
  color: var(--rb-heading);
}

/* --- Title ::before → "EXERCISE N" counter --------------------------------- */
.md-typeset .exercise-easy > .admonition-title::before,
.md-typeset .exercise-easy > summary::before,
.md-typeset .exercise-intermediate > .admonition-title::before,
.md-typeset .exercise-intermediate > summary::before,
.md-typeset .exercise-hard > .admonition-title::before,
.md-typeset .exercise-hard > summary::before {
  content: "EXERCISE " counter(exercise) "\a0\a0";
  font-size: 0.75em;
  letter-spacing: 0.1em;
  font-weight: 600;
  font-style: normal;
  /* Reset Material icon rendering */
  background-color: transparent;
  mask-image: none;
  -webkit-mask-image: none;
  position: static;
  display: inline;
  width: auto;
  height: auto;
  margin: 0;
  vertical-align: baseline;
}

/* --- Difficulty label (non-collapsible only) via ::after -------------------- */
.md-typeset .exercise-easy > .admonition-title::after {
  content: "(easy)";
  color: var(--rb-gruvbox-green);
}
.md-typeset .exercise-intermediate > .admonition-title::after {
  content: "(intermediate)";
  color: var(--rb-gruvbox-yellow-dark);
}
.md-typeset .exercise-hard > .admonition-title::after {
  content: "(hard)";
  color: var(--rb-gruvbox-red);
}

/* Shared difficulty label style */
.md-typeset .exercise-easy > .admonition-title::after,
.md-typeset .exercise-intermediate > .admonition-title::after,
.md-typeset .exercise-hard > .admonition-title::after {
  font-size: 0.8em;
  font-style: italic;
  margin-left: 0.5em;
  /* Reset Material ::after */
  background: none;
  mask-image: none;
  -webkit-mask-image: none;
  position: static;
  display: inline;
  width: auto;
  height: auto;
}

/* --- Definition list <dt> inside exercises: bold with appended colon -------- */
.md-typeset .admonition.exercise-easy dt,
.md-typeset .admonition.exercise-intermediate dt,
.md-typeset .admonition.exercise-hard dt,
.md-typeset details.exercise-easy dt,
.md-typeset details.exercise-intermediate dt,
.md-typeset details.exercise-hard dt {
  font-weight: 700;
}
.md-typeset .admonition.exercise-easy dt::after,
.md-typeset .admonition.exercise-intermediate dt::after,
.md-typeset .admonition.exercise-hard dt::after,
.md-typeset details.exercise-easy dt::after,
.md-typeset details.exercise-intermediate dt::after,
.md-typeset details.exercise-hard dt::after {
  content: ":";
}


/* For collapsible exercises, ::after is used by Material's chevron.
   Color the counter text instead to communicate difficulty. */
.md-typeset details.exercise-easy > summary::before {
  color: var(--rb-gruvbox-green);
}
.md-typeset details.exercise-intermediate > summary::before {
  color: var(--rb-gruvbox-yellow-dark);
}
.md-typeset details.exercise-hard > summary::before {
  color: var(--rb-gruvbox-red);
}

/* --- Wide screen: hints inside exercises float to margin ------------------- */
@media (min-width: 1400px) {
  .md-typeset [class*="exercise-"] .margin-note {
    position: absolute;
    right: -18rem;
    width: 15rem;
    float: none;
    margin: 0;
  }
}

/* --- Wide screen: exercises stay full-width, never float to margin --------- */
@media (min-width: 1400px) {
  .md-typeset .admonition.exercise-easy,
  .md-typeset .admonition.exercise-intermediate,
  .md-typeset .admonition.exercise-hard,
  .md-typeset details.exercise-easy,
  .md-typeset details.exercise-intermediate,
  .md-typeset details.exercise-hard {
    float: none;
    clear: both;
    width: 100%;
    margin-right: 0;
    font-size: inherit;
    background: transparent;
    border: none;
    padding: 0;
    box-shadow: none;
  }

  .md-typeset .exercise-easy > .admonition-title,
  .md-typeset .exercise-easy > summary,
  .md-typeset .exercise-intermediate > .admonition-title,
  .md-typeset .exercise-intermediate > summary,
  .md-typeset .exercise-hard > .admonition-title,
  .md-typeset .exercise-hard > summary {
    background: transparent;
    border-bottom: none;
    font-size: inherit;
    padding: 0 0 0.4rem 0;
  }
}