:root {
  --bg: #f6f8fb;
  --panel: #ffffff;
  --text: #1f2937;
  --muted: #6b7280;
  --border: #e5e7eb;
  --accent: #2563eb;
  --soft: #eef2ff;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: Inter, Segoe UI, Roboto, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: #fff;
  border-bottom: 1px solid var(--border);
}
.topbar {
  width: 80%;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 14px 0;
}
.brand { font-weight: 800; }
nav { display: flex; gap: 14px; }
.layout {
  width: 80%;
  margin: 18px auto;
  padding: 0;
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: 16px;
}
.home-layout {
  width: 80%;
  margin: 18px auto;
  padding: 0;
}
.box {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px;
}
.hero {
  background: var(--soft);
  border: 1px solid #c7d2fe;
  border-radius: 12px;
  padding: 20px;
  margin-bottom: 14px;
}
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 12px;
}
.category-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 12px;
}
.card {
  border: 1px solid var(--border);
  border-radius: 10px;
  background: #fff;
  padding: 14px;
}
.mcq-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.mcq-card h3 { margin-top: 0; }
.mcq-options {
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.mcq-option {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: 8px;
}
.mcq-option.ok {
  border-color: #16a34a;
  background: #f0fdf4;
}
.mcq-option.bad {
  border-color: #dc2626;
  background: #fef2f2;
}
.mcq-feedback {
  margin-top: 10px;
  padding: 8px 10px;
  border-radius: 8px;
  border: 1px solid var(--border);
}
.mcq-answer,
.mcq-explanation {
  margin-top: 8px;
}
.mcq-feedback.ok {
  color: #166534;
  background: #f0fdf4;
  border-color: #bbf7d0;
}
.mcq-feedback.bad {
  color: #991b1b;
  background: #fef2f2;
  border-color: #fecaca;
}
.search {
  width: 100%;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px 12px;
  margin: 8px 0 14px;
}
ol, ul { padding-left: 20px; }
.sidebar-group {
  margin: 10px 0;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 6px 10px;
  background: #fff;
}
.sidebar-group summary {
  cursor: pointer;
  font-weight: 600;
}
.sidebar-group ul {
  margin-top: 8px;
}
.muted { color: var(--muted); }
.active { font-weight: 700; }
.hide { display: none !important; }
footer {
  width: 80%;
  margin: 22px auto 28px;
  padding: 0;
  color: var(--muted);
  font-size: 14px;
}
.mcq-more-links {
  margin: 20px 0 4px;
  padding: 12px 16px;
  background: var(--soft);
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 14px;
  line-height: 2;
}
.mcq-more-links a {
  color: var(--accent);
  font-weight: 500;
}
.mcq-more-links a:hover { text-decoration: underline; }
.mcq-pagination {
  display: flex;
  gap: 12px;
  align-items: center;
  margin: 24px 0 8px;
  flex-wrap: wrap;
}
.mcq-pagination a {
  display: inline-block;
  padding: 8px 18px;
  border: 1px solid var(--accent);
  border-radius: 6px;
  font-weight: 600;
  color: var(--accent);
  background: var(--soft);
  text-decoration: none;
}
.mcq-pagination a:hover {
  background: var(--accent);
  color: #fff;
}
.mcq-pagination .pg-info {
  color: var(--muted);
  font-size: 14px;
}
@media (max-width: 860px) {
  .layout { grid-template-columns: 1fr; }
}