/* Approved chapter setup treatment: diffused silver fades into black.
   Scoped to the detail view; sky, sidebar, catalogue and test player stay intact. */
.portal-shell .practice-catalogue.topic-detail,
.practice-catalogue.topic-detail {
  color:#f5f6f7;
}
.practice-catalogue.topic-detail .topic-back { color:#c4cbd2; margin-bottom:20px; font-size:13px; }
.practice-catalogue.topic-detail .topic-back:hover { color:#fff; }
.practice-catalogue.topic-detail .topic-hero {
  grid-template-columns:116px minmax(0,1fr);
  min-height:168px;
  gap:28px;
  padding:25px 32px;
  border-radius:15px;
  border:1px solid #4d545b;
  background:linear-gradient(180deg,#4d5054 0%,#34393e 17%,#20262b 41%,#0e1318 71%,#050709 100%);
  box-shadow:none;
}
.practice-catalogue.topic-detail .topic-hero-art {
  width:116px;height:116px;
  background:#101821;
  border:1px solid #3d4a56;
  border-radius:13px;
}
.practice-catalogue.topic-detail .topic-hero-art svg {width:104px;height:82px}
.practice-catalogue.topic-detail .topic-hero-copy .eyebrow {
  color:#c2c9d0;font-size:11px;font-weight:700;letter-spacing:.12em;
}
.practice-catalogue.topic-detail .topic-hero-copy h1 {
  color:#f8f9fa;font-size:clamp(30px,3vw,44px);
  line-height:1.15;letter-spacing:-.045em;
}
.practice-catalogue.topic-detail .topic-hero-copy p {
  color:#c3cbd2;font-size:14px;line-height:1.6;max-width:67ch;
}
.practice-catalogue.topic-detail .topic-choice-stage {
  display:grid;
  grid-template-columns:minmax(0,1fr) minmax(0,1fr);
  margin-top:22px;
  border:1px solid #41484e;
  border-radius:15px;
  overflow:hidden;
  background:linear-gradient(180deg,#45494d 0%,#30353a 17%,#171d22 42%,#0b1014 70%,#050709 100%);
  box-shadow:none;
}
.practice-catalogue.topic-detail .topic-choice-stage > section {
  min-width:0;
  padding:31px 33px 28px;
}
.practice-catalogue.topic-detail .topic-difficulty-section {
  display:flex;flex-direction:column;justify-content:space-between;
  border-right:1px solid #475158;
}
.practice-catalogue.topic-detail .topic-difficulty-section > .topic-group-heading {
  margin:0 0 31px;
}
.practice-catalogue.topic-detail .topic-stage-eyebrow,
.practice-catalogue.topic-detail .topic-session-heading > span {
  display:block;color:#c5cdd5;font-size:10px;font-weight:750;
  letter-spacing:.15em;text-transform:uppercase;margin-bottom:9px;
}
.practice-catalogue.topic-detail .topic-difficulty-section h2,
.practice-catalogue.topic-detail .topic-session-heading h2 {
  color:#f8f9fb;font:700 clamp(21px,2vw,27px)/1.23 Manrope,Inter,sans-serif;
  letter-spacing:-.045em;margin:0;
}
.practice-catalogue.topic-detail .topic-difficulty-section > .topic-group-heading p {
  color:#c2cbd2;font-size:13px;margin-top:9px;line-height:1.5;
}
.practice-catalogue.topic-detail .topic-difficulty-section > div:last-child {
  max-width:460px!important;width:100%;
  margin:0 auto 0;
}
.practice-catalogue.topic-detail .mega-difficulty {
  --difficulty-orange:#19c5c4;
  --difficulty-ember:#148d9b;
  width:100%;min-width:0;max-width:460px;
  border:1px solid #405966;
  background:linear-gradient(180deg,#121b22,#0c1116);
  box-shadow:none;
}
.practice-catalogue.topic-detail .mega-difficulty > label { color:#b8c6cf; }
.practice-catalogue.topic-detail .mega-difficulty #practice-difficulty-value { color:#66eeee; }
.practice-catalogue.topic-detail .mega-range-track {
  border-color:#25565b;
  background:linear-gradient(180deg,#174149,#10292f);
}
.practice-catalogue.topic-detail .mega-difficulty[data-level] .mega-range-fill {
  background:linear-gradient(100deg,#148c99 0%,#1bb9c2 56%,#30e1d5 100%);
  box-shadow:inset 0 1px 0 #b1ffff70,0 0 14px #24d5ce40;
}
.practice-catalogue.topic-detail .mega-range-ticks i,
.practice-catalogue.topic-detail .mega-difficulty[data-level="1"] .mega-range-ticks i:first-child,
.practice-catalogue.topic-detail .mega-difficulty[data-level="2"] .mega-range-ticks i {background:#bcffff}
.practice-catalogue.topic-detail .mega-range-spark > i::before {
  background:linear-gradient(90deg,transparent,#bbffff50,#eaffffaa);
  box-shadow:5px 0 8px #5ff5ec77;
}
.practice-catalogue.topic-detail .mega-range-spark > i::after {background:#d8ffff}
.practice-catalogue.topic-detail .mega-range-thumb {
  border-color:#9afff8;
  background:linear-gradient(145deg,#b9ffff,#4aebe1 55%,#16b7bc);
  box-shadow:inset 0 1px 0 #fff9,0 0 0 3px #01232955,0 3px 9px #0009;
}
.practice-catalogue.topic-detail .mega-range-thumb > i {background:#10333a}
.practice-catalogue.topic-detail .mega-range:has(input:focus-visible) {outline-color:#5df4ed}
.practice-catalogue.topic-detail .mega-range:has(input:hover) .mega-range-thumb,
.practice-catalogue.topic-detail .mega-range:has(input:focus-visible) .mega-range-thumb {
  box-shadow:inset 0 1px 0 #fffa,0 0 0 4px #26ddd544,0 3px 11px #000a;
}
.practice-catalogue.topic-detail .mega-difficulty .mega-range-labels .text-link {color:#b6c5cc}
.practice-catalogue.topic-detail .mega-difficulty .mega-range-labels .text-link:hover {color:#edffff}
.practice-catalogue.topic-detail .mega-difficulty .mega-range-labels [aria-pressed="true"] {
  color:#b2ffff;background:#21c6c31b;border-color:#62e9e866;
}
.practice-catalogue.topic-detail #chapter-selected-panel {min-width:0}
.practice-catalogue.topic-detail .topic-session-heading {margin:0 0 23px}
.practice-catalogue.topic-detail .topic-detail-stats {
  grid-template-columns:1.1fr .95fr 1.2fr;
  padding:0 0 26px;
  margin:0 0 23px;
  border-bottom:1px solid #465058;
}
.practice-catalogue.topic-detail .topic-detail-stats > div {
  min-width:0;padding:0 13px;border-color:#455058;
}
.practice-catalogue.topic-detail .topic-detail-stats > div:first-child {padding-left:0}
.practice-catalogue.topic-detail .topic-detail-stats > div:last-child {padding-right:0}
.practice-catalogue.topic-detail .topic-detail-stats > div > span {
  color:#c1cbd3;font-size:11px;line-height:1.45;margin:0;
}
.practice-catalogue.topic-detail .topic-detail-stats strong {
  color:#f7f9fa;font-size:clamp(22px,2.5vw,38px);
  line-height:1.25;font-weight:740;letter-spacing:-.045em;
  margin-top:9px;font-variant-numeric:tabular-nums;
}
.practice-catalogue.topic-detail .topic-detail-stats strong[style] {
  font-size:clamp(18px,1.85vw,24px)!important;letter-spacing:-.045em;
  margin-top:15px;white-space:nowrap;
}
.practice-catalogue.topic-detail .topic-detail-stats > div > small {
  color:#b8c3cc;font-size:10px;line-height:1.45;margin-top:1px;
}
.practice-catalogue.topic-detail .topic-hero-actions {
  flex-direction:row-reverse;align-items:flex-end;justify-content:space-between;gap:18px;
}
.practice-catalogue.topic-detail .topic-hero-actions > span {
  max-width:200px;color:#c4cbd0;text-align:left;font-size:11px;line-height:1.55;
}
.practice-catalogue.topic-detail .topic-hero-actions .btn.primary {
  width:auto;min-width:178px;min-height:47px;padding:11px 19px;
  border:1px solid #dce5ee;border-radius:8px;
  color:#19212b;background:#e8eef4;box-shadow:none;
  font-size:13px;font-weight:700;
}
.practice-catalogue.topic-detail .topic-hero-actions .btn.primary:hover {
  color:#090f15;background:#fff;border-color:#fff;
}
.practice-catalogue.topic-detail .topic-format-note {
  margin:22px 0 0;padding:18px 2px;
  background:transparent;border:0;border-top:1px solid #394249;
  border-radius:0;color:#b6c1c9;font-size:11px;
}
.practice-catalogue.topic-detail .topic-format-note strong {
  color:#e4e9ee;font-size:12px;
}
@media (max-width:1180px) {
  .practice-catalogue.topic-detail .topic-choice-stage > section {padding:26px 24px}
  .practice-catalogue.topic-detail .topic-detail-stats > div {padding:0 9px}
}
@media (max-width:830px) {
  .practice-catalogue.topic-detail .topic-choice-stage {grid-template-columns:1fr}
  .practice-catalogue.topic-detail .topic-difficulty-section {border-right:0;border-bottom:1px solid #465058;gap:25px}
  .practice-catalogue.topic-detail .topic-difficulty-section > div:last-child {margin:0;max-width:460px}
  .practice-catalogue.topic-detail .topic-choice-stage > section {padding:26px 24px}
  .practice-catalogue.topic-detail .topic-hero {grid-template-columns:85px 1fr;gap:18px;padding:22px}
  .practice-catalogue.topic-detail .topic-hero-art {width:85px;height:85px}
  .practice-catalogue.topic-detail .topic-hero-art svg {width:79px;height:63px}
}
@media (max-width:470px) {
  .practice-catalogue.topic-detail .topic-hero {grid-template-columns:1fr}
  .practice-catalogue.topic-detail .topic-detail-stats {gap:8px;grid-template-columns:1fr 1fr 1fr}
  .practice-catalogue.topic-detail .topic-detail-stats strong[style] {font-size:16px!important;white-space:normal;margin-top:13px}
  .practice-catalogue.topic-detail .topic-hero-actions {align-items:stretch;flex-direction:column}
  .practice-catalogue.topic-detail .topic-hero-actions .btn.primary {width:100%}
  .practice-catalogue.topic-detail .topic-hero-actions > span {max-width:none}
}