/* Home page lessons by the book: Tập 1 / Tập 2 tabs, chapters and lesson cards. */

.bk-home {
  margin: 8px 0 40px;
}

.bk-tabs {
  position: sticky;
  top: 0;
  z-index: 5;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin: 0 0 20px;
  padding: 8px 0;
  background: var(--bg, #fff7ea);
}

.bk-tab {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0;
  padding: 10px 12px;
  border: 2px solid var(--line);
  border-radius: 18px;
  background: var(--surface);
  box-shadow: 0 4px 0 var(--line);
  color: var(--ink);
  font: inherit;
  font-size: 1.35rem;
  font-weight: 800;
  line-height: 1.15;
  cursor: pointer;
}

.bk-tab small {
  color: var(--ink-soft);
  font-size: 0.8rem;
  font-weight: 700;
}

.bk-tab[aria-selected="true"] {
  border-color: var(--brand-deep);
  background: var(--brand);
  box-shadow: 0 4px 0 var(--brand-deep);
  color: #fff;
}

.bk-tab[aria-selected="true"] small {
  color: rgba(255, 255, 255, 0.9);
}

.bk-tab:focus-visible {
  outline: 3px solid var(--brand-deep);
  outline-offset: 3px;
}

.bk-home-lead {
  margin: 0 0 18px;
  color: var(--ink-soft);
}

.bk-extra h3 {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 4px 10px;
  margin: 8px 0 12px;
  font-size: 1.15rem;
}

.bk-extra h3 span {
  padding: 2px 10px;
  border-radius: 999px;
  background: var(--good-deep, #2e8b57);
  color: #fff;
  font-size: 0.8rem;
}

.bk-chapter {
  margin-bottom: 26px;
}

.bk-chapter h3 {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 4px 10px;
  margin: 0 0 12px;
  font-size: 1.15rem;
  line-height: 1.25;
}

.bk-chapter h3 span {
  padding: 2px 10px;
  border-radius: 999px;
  background: var(--brand);
  color: #fff;
  font-size: 0.8rem;
}

.bk-cards {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 12px;
}

.bk-card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 14px;
  border: 2px solid var(--line);
  border-radius: 18px;
  background: var(--surface);
  box-shadow: 0 4px 0 var(--line);
}

.bk-card.is-started {
  border-color: var(--good);
  box-shadow: 0 4px 0 var(--good-deep);
}

.bk-card-main {
  display: flex;
  flex-direction: column;
  gap: 2px;
  text-decoration: none;
}

.bk-card-main:hover .bk-card-title {
  color: var(--brand-deep);
}

.bk-card-no {
  color: var(--brand-deep);
  font-size: 0.85rem;
  font-weight: 800;
}

.bk-card-title {
  font-weight: 700;
  line-height: 1.25;
}

.bk-card-pages {
  color: var(--ink-soft);
  font-size: 0.8rem;
}

.bk-parts {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin: auto 0 0;
  padding: 0;
  list-style: none;
}

.bk-part {
  display: inline-block;
  padding: 3px 10px;
  border: 2px solid var(--line);
  border-radius: 999px;
  color: var(--ink-soft);
  font-size: 0.78rem;
  font-weight: 700;
  text-decoration: none;
}

.bk-part:hover {
  border-color: var(--brand);
  color: var(--ink);
}

.bk-part.is-done {
  border-color: var(--good);
  background: var(--good);
  color: #fff;
}

.bk-card-stars {
  position: absolute;
  top: 12px;
  right: 12px;
  display: inline-flex;
  gap: 1px;
}

.bk-card-stars .star {
  width: 16px;
  height: 16px;
}

@media (prefers-color-scheme: dark) {
  .bk-card-no {
    color: var(--brand);
  }
}