/* Interview Q&A drills — DevNinja theme */
.interview-drill {
  margin-top: 2.75rem;
  padding-top: 1.75rem;
  border-top: 1px solid var(--border);
}

.interview-drill > h2 {
  margin-top: 0 !important;
}

.drill-intro {
  color: var(--text-secondary);
  margin: 0.5rem 0 1.25rem !important;
}

.qa {
  border: 1px solid var(--border);
  background: var(--surface);
  margin: 0.75rem 0;
  overflow: hidden;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
}

.qa + .qa {
  margin-top: 0.65rem;
}

.qa summary {
  cursor: pointer;
  list-style: none;
  padding: 0.95rem 1rem;
  font-weight: 650;
  color: var(--text-primary);
  display: flex;
  gap: 0.65rem;
  align-items: flex-start;
}

.qa summary::-webkit-details-marker {
  display: none;
}

.qa summary::before {
  content: "+";
  font-family: var(--font-mono);
  color: var(--primary-600);
  flex: 0 0 auto;
  margin-top: 0.05rem;
}

.qa[open] summary::before {
  content: "–";
}

.qa summary:hover {
  background: var(--primary-50);
}

.qa-body {
  padding: 0 1rem 1.1rem;
  border-top: 1px solid var(--border-light);
}

.qa-body > * + * {
  margin-top: 0.85rem;
}

.qa-label {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--primary-700);
  font-weight: 700;
  margin-bottom: 0.25rem;
}

.qa-meta {
  font-size: 0.86rem;
  color: var(--text-muted);
  margin: 0 !important;
}

.lab-hero-note {
  margin: 0.75rem 0 0;
  color: var(--text-secondary);
}

.qa-body ul {
  margin: 0.35rem 0 0;
  padding-left: 1.2rem;
}

.qa-body li {
  margin: 0.3rem 0;
}

.qa-body strong {
  font-weight: 650;
}

.qa-steps {
  margin: 0.35rem 0 0;
  padding-left: 1.35rem;
}

.qa-steps > li {
  margin: 0.55rem 0;
  padding-left: 0.25rem;
}

.qa-diagram {
  margin: 1rem 0 0.35rem !important;
  background: #fbfcfd;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
}

.qa-diagram img {
  width: 100%;
  height: auto;
  display: block;
  background: #fbfcfd;
}

.qa-callout {
  margin-top: 0.85rem;
  padding: 0.85rem 1rem;
  background: var(--primary-50);
  border-left: 3px solid var(--primary-500);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
}

.qa-callout .qa-label {
  margin-bottom: 0.35rem;
}

.lab-toc {
  margin: 1rem 0 1.5rem;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0.35rem;
}

.lab-toc a {
  color: var(--text-primary);
  text-decoration: none;
  font-weight: 550;
}

.lab-toc a:hover {
  color: var(--primary-700);
}

.lab-toc span {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--primary-600);
  margin-right: 0.45rem;
}

.chapter-page .part a {
  color: inherit;
  text-decoration: none;
}

.chapter-page .part a:hover {
  color: var(--primary-700);
}

.page-meta-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem 1.1rem;
  margin: 0.85rem 0 1.15rem;
  padding: 0.7rem 0.9rem;
  background: var(--primary-50);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  font-size: 0.86rem;
  color: var(--text-secondary);
}

.page-meta-bar strong {
  color: var(--text-primary);
  font-weight: 650;
  margin-right: 0.25rem;
}

.level-table caption {
  caption-side: top;
  text-align: left;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--primary-700);
  font-weight: 700;
  margin-bottom: 0.4rem;
}

.level-table th[scope="row"] {
  white-space: nowrap;
  width: 6.5rem;
  color: var(--text-primary);
  font-weight: 650;
}

.learn-box {
  margin: 1rem 0 1.35rem;
  padding: 0.9rem 1rem;
  border-left: 3px solid var(--primary-500);
  background: var(--primary-50);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
}

.learn-box-next {
  border-left-color: var(--gray-800);
  background: var(--surface-muted);
}

.learn-box .qa-label {
  margin-bottom: 0.4rem;
}

.learn-box ul,
.next-topics {
  margin: 0.25rem 0 0;
  padding-left: 1.2rem;
}

.progress-bar-wrap {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin: 0.5rem 0 1.25rem;
}

.progress-bar {
  flex: 1;
  min-width: 140px;
  height: 0.55rem;
  background: var(--gray-200);
  border-radius: 999px;
  overflow: hidden;
}

.progress-bar > span {
  display: block;
  height: 100%;
  width: 0%;
  background: var(--primary-600);
  transition: width 0.25s ease;
}

.progress-label {
  font-size: 0.84rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

.qa.done > summary {
  background: var(--primary-50);
}

.mark-done {
  margin-top: 0.75rem;
  font-size: 0.86rem;
}

.mark-done button {
  font: inherit;
  cursor: pointer;
  border: 1px solid var(--border);
  background: #fff;
  border-radius: var(--radius-md);
  padding: 0.35rem 0.7rem;
  color: var(--text-primary);
}

.mark-done button:hover {
  border-color: var(--primary-500);
  color: var(--primary-700);
  background: var(--primary-50);
}

.toc-item .num.guide {
  color: #b45309;
}