/* ============================================================
   COURSE DETAIL — Page-specific styles
   ============================================================ */

/* BREADCRUMB */
.crumbs {
  padding: 16px 24px 0;
  font-size: var(--step--1);
  color: var(--muted);
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  max-width: 1180px;
  margin: 0 auto;
}
.crumbs a:hover { color: var(--accent-2) }

/* HERO KHOÁ HỌC */
.chero {
  position: relative;
  padding: 22px 24px 40px;
  overflow: hidden;
}
.chero::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(
    120% 100% at 15% 0%,
    var(--accent-tint),
    transparent 55%
  );
  z-index: -1;
}
.chero-inner {
  max-width: 1180px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.5fr 1fr;
  gap: 40px;
  align-items: start;
}
.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 11px;
  border-radius: 999px;
  background: var(--surface-2);
  border: 1px solid var(--line);
  color: var(--text-2);
  font-size: var(--step--1);
}
.chip--accent {
  background: var(--accent-tint);
  color: var(--accent-2);
  border-color: transparent;
  font-weight: 700;
}
.chero h1 {
  font-size: clamp(2.1rem, 1.7rem + 2vw, 3rem);
  line-height: 1.14;
  letter-spacing: -.03em;
  font-weight: 800;
  margin: 14px 0 12px;
}
.chero .lede {
  color: var(--text-2);
  font-size: var(--step-1);
  max-width: 60ch;
  margin: 0 0 18px;
}
.meta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  align-items: center;
  font-size: var(--step--1);
  color: var(--text-2);
  margin-bottom: 6px;
}
.meta-row b { color: var(--text) }
.rating-inline {
  display: flex;
  align-items: center;
  gap: 6px;
  color: var(--star);
  font-weight: 800;
}
.rating-inline a {
  color: var(--muted);
  font-weight: 500;
  text-decoration: underline;
}
.instr-row {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-top: 16px;
}
.instr-row small {
  display: block;
  color: var(--muted);
  font-size: .78rem;
}
.instr-row b { font-size: var(--step--1) }

/* BUY CARD */
.buy-card {
  position: sticky;
  top: calc(var(--topbar-h) + 20px);
  border: 1px solid var(--line);
  border-radius: 16px;
  background: var(--surface);
  box-shadow: var(--shadow);
  overflow: hidden;
}
.buy-card__preview {
  aspect-ratio: 16/9;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  position: relative;
  display: grid;
  place-items: center;
  cursor: pointer;
}
.buy-card__preview svg { color: #fff; width: 52px; height: 52px }
.buy-card__preview span {
  position: absolute;
  bottom: 10px;
  left: 12px;
  background: rgba(0, 0, 0, .55);
  color: #fff;
  font-size: .7rem;
  font-weight: 700;
  padding: 3px 9px;
  border-radius: 999px;
}
.buy-card__body { padding: 20px }
.price-row {
  display: flex;
  align-items: baseline;
  gap: 10px;
  margin-bottom: 4px;
}
.price-now {
  font-size: var(--step-3);
  font-weight: 800;
  letter-spacing: -.02em;
}
.price-old {
  color: var(--muted);
  text-decoration: line-through;
  font-size: var(--step-0);
}
.price-pct {
  color: var(--ok);
  font-weight: 700;
  font-size: var(--step--1);
}
.price-timer {
  font-size: var(--step--1);
  color: var(--danger);
  font-weight: 600;
  margin-bottom: 16px;
}
.buy-card__actions {
  display: grid;
  gap: 10px;
  margin-bottom: 16px;
}
.buy-card__guarantee {
  text-align: center;
  font-size: .75rem;
  color: var(--muted);
  margin-bottom: 16px;
}
.incl-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 9px;
  border-top: 1px solid var(--line-soft);
  padding-top: 16px;
}
.incl-list li {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  font-size: var(--step--1);
  color: var(--text-2);
}
.incl-list svg { flex: none; margin-top: 2px; color: var(--accent-2) }

/* SECTIONS (course detail override) */
.section {
  padding: 44px 24px;
  max-width: 1180px;
  margin: 0 auto;
}
.section h2 {
  font-size: var(--step-2);
  font-weight: 800;
  letter-spacing: -.02em;
  margin: 0 0 20px;
}
.dgrid {
  display: grid;
  grid-template-columns: 1.5fr 1fr;
  gap: 40px;
  align-items: start;
}

/* LEARN GRID */
.learn-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px;
  background: var(--surface-2);
}
.learn-item {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  font-size: var(--step--1);
  color: var(--text-2);
}
.learn-item svg { flex: none; margin-top: 2px; color: var(--ok) }

/* CURRICULUM ACCORDION */
.curr-summary {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  align-items: center;
  margin-bottom: 14px;
  font-size: var(--step--1);
  color: var(--text-2);
}
.curr-summary button {
  margin-left: auto;
  font-weight: 700;
  color: var(--accent-2);
}
.curr-summary button:hover { text-decoration: underline }
.curr {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}
.curr__group + .curr__group { border-top: 1px solid var(--line) }
.curr__toggle {
  width: 100%;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px 18px;
  background: var(--surface-2);
  text-align: left;
  font-weight: 700;
}
.curr__toggle .chev {
  margin-left: auto;
  transition: transform .2s;
  color: var(--muted);
  flex: none;
}
.curr__group[data-open="true"] .chev { transform: rotate(180deg) }
.curr__toggle small {
  display: block;
  font-weight: 400;
  color: var(--muted);
  font-size: .78rem;
  margin-top: 2px;
}
.curr__items {
  list-style: none;
  margin: 0;
  padding: 0;
  display: none;
}
.curr__group[data-open="true"] .curr__items { display: block }
.curr__item {
  display: flex;
  align-items: center;
  gap: 11px;
  padding: 12px 18px;
  border-top: 1px solid var(--line-soft);
  font-size: var(--step--1);
  color: var(--text-2);
}
.curr__item svg { flex: none; color: var(--muted) }
.curr__item.is-preview svg { color: var(--accent-2) }
.curr__item b {
  margin-left: 2px;
  font-weight: 600;
  color: var(--text);
}
.curr__item .dur {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: .75rem;
  color: var(--muted);
}
.curr__item .preview-tag {
  color: var(--accent-2);
  font-weight: 700;
  font-size: .72rem;
  text-transform: uppercase;
  letter-spacing: .05em;
  margin-left: 8px;
}

/* REQUIREMENTS / AUDIENCE */
.plain-list { margin: 0; padding-left: 20px; color: var(--text-2) }
.plain-list li { margin-bottom: 8px }
.plain-list li::marker { color: var(--accent) }

/* TEACHER CARD */
.teacher-card {
  display: flex;
  gap: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px;
  background: var(--surface);
}
.teacher-card__stats {
  display: flex;
  gap: 18px;
  flex-wrap: wrap;
  margin: 10px 0 12px;
  font-size: .78rem;
  color: var(--muted);
}
.teacher-card__stats b {
  color: var(--text);
  display: block;
  font-size: var(--step-0);
}
.teacher-card p {
  color: var(--text-2);
  font-size: var(--step--1);
  margin: 0;
}

/* REVIEWS */
.rev-summary {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 36px;
  align-items: center;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-2);
  margin-bottom: 22px;
}
.rev-score { text-align: center }
.rev-score b {
  display: block;
  font-size: clamp(2.1rem, 1.7rem + 2vw, 3rem);
  font-weight: 800;
  line-height: 1;
}
.rev-score .stars {
  color: var(--star);
  margin: 6px 0;
  font-size: 1.1rem;
}
.rev-score span { font-size: .78rem; color: var(--muted) }
.rev-bars { display: grid; gap: 6px }
.rev-bar-row {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: .78rem;
  color: var(--text-2);
}
.rev-bar-row .track {
  flex: 1;
  height: 8px;
  border-radius: 8px;
  background: var(--surface-3);
  overflow: hidden;
}
.rev-bar-row .track i {
  display: block;
  height: 100%;
  background: var(--star);
  width: 0;
  transition: width .5s ease;
}
.rev-bar-row .n {
  width: 34px;
  text-align: right;
  color: var(--muted);
}
.rev-filters {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 16px;
}
.rev-list { display: grid; gap: 18px }
.rev {
  border-bottom: 1px solid var(--line-soft);
  padding-bottom: 18px;
}
.rev__top {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 8px;
}
.rev__name { font-weight: 700; font-size: var(--step--1) }
.rev__time { color: var(--muted); font-size: .74rem }
.rev__stars {
  color: var(--star);
  font-size: .8rem;
  margin-left: auto;
}
.rev p {
  margin: 0;
  color: var(--text-2);
  font-size: var(--step--1);
  line-height: 1.7;
}
.rev-more { margin: 6px auto 0; display: block }

/* FAQ */
.faq {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}
.faq__item + .faq__item { border-top: 1px solid var(--line) }
.faq__q {
  width: 100%;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px 18px;
  text-align: left;
  font-weight: 700;
  background: var(--surface);
}
.faq__q .chev {
  margin-left: auto;
  transition: transform .2s;
  color: var(--muted);
  flex: none;
}
.faq__item[data-open="true"] .chev { transform: rotate(180deg) }
.faq__a {
  display: none;
  padding: 0 18px 18px;
  color: var(--text-2);
  font-size: var(--step--1);
  max-width: 70ch;
}
.faq__item[data-open="true"] .faq__a { display: block }

/* COURSE GRID (course detail) */
.course-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 20px;
}

/* STEP HEADERS (unified course) */
.curr__step-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 14px 20px;
  margin-top: 16px;
  background: linear-gradient(135deg,
    var(--accent) 0%, var(--accent-2) 100%);
  border-radius: var(--radius);
  color: #fff;
}
.curr__step-header:first-child { margin-top: 0; }
.curr__step-header h3 {
  margin: 0;
  font-size: var(--step-0);
  font-weight: 700;
}
.curr__step-header span {
  font-size: var(--step--1);
  opacity: .9;
}

/* MOBILE STICKY CTA */
.mobile-cta {
  display: none;
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 90;
  padding: 12px 16px;
  background: var(--surface);
  border-top: 1px solid var(--line);
  box-shadow: 0 -8px 20px rgba(0, 0, 0, .08);
  gap: 12px;
  align-items: center;
}
.mobile-cta b { font-size: var(--step-1) }
.mobile-cta .btn { flex: 1 }

/* LIGHTBOX PREVIEW */
.lightbox {
  position: fixed;
  inset: 0;
  z-index: 250;
  background: rgba(10, 9, 19, .82);
  display: none;
  align-items: center;
  justify-content: center;
  padding: 24px;
}
.lightbox.is-on { display: flex }
.lightbox__panel {
  max-width: 760px;
  width: 100%;
  background: var(--surface);
  border-radius: 16px;
  overflow: hidden;
  box-shadow: var(--shadow);
}
.lightbox__bar {
  display: flex;
  align-items: center;
  padding: 12px 16px;
  border-bottom: 1px solid var(--line-soft);
}
.lightbox__bar b { font-size: var(--step--1) }
.lightbox__close { margin-left: auto }
.lightbox__body {
  aspect-ratio: 16/9;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  display: grid;
  place-items: center;
  color: #fff;
  text-align: center;
  padding: 24px;
}

footer.foot { margin-top: 20px }

@media (max-width: 920px) {
  .chero-inner { grid-template-columns: 1fr }
  .dgrid { grid-template-columns: 1fr }
  .buy-card { position: static; display: none }
  .learn-grid { grid-template-columns: 1fr }
  .mobile-cta { display: flex }
  body { padding-bottom: 76px }
}