:root {
  --bg: #f6f7f4;
  --card-bg: #ffffff;
  --border: #d8dcd3;
  --text: #23291f;
  --text-muted: #6b7266;
  --accent: #3d6b3d;
  --accent-bg: #e9f0e6;
  --ok: #2e7d32;
  --ok-bg: #e6f4e6;
  --pending: #a3792f;
  --pending-bg: #f7edd9;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  font-size: 15px;
  line-height: 1.5;
}

.topbar {
  background: var(--card-bg);
  border-bottom: 1px solid var(--border);
  padding: 14px 24px;
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 8px;
}

.brand {
  font-weight: 700;
  font-size: 1.1em;
  color: var(--text);
  text-decoration: none;
}
.brand-sub {
  font-weight: 400;
  color: var(--text-muted);
  font-size: 0.85em;
  margin-left: 8px;
}

.methodology-link {
  color: var(--accent);
  text-decoration: none;
  font-size: 0.9em;
}
.methodology-link:hover { text-decoration: underline; }

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 20px 16px 60px;
}

.filters {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  align-items: end;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 16px;
  margin-bottom: 16px;
}
.filter-field { display: flex; flex-direction: column; gap: 4px; }
.filter-field label { font-size: 0.78em; color: var(--text-muted); }
.filter-field select, .filter-field input {
  padding: 7px 8px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 0.9em;
  background: white;
  min-width: 160px;
}
.filter-field-search input { min-width: 200px; }
.filters button {
  padding: 8px 16px;
  background: var(--accent);
  color: white;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  font-size: 0.9em;
}
.reset-link { font-size: 0.85em; color: var(--text-muted); align-self: center; }

.result-count { color: var(--text-muted); font-size: 0.9em; }

.q-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  overflow: hidden;
}
.q-table th, .q-table td {
  padding: 10px 12px;
  text-align: left;
  border-bottom: 1px solid var(--border);
  font-size: 0.9em;
}
.q-table th { background: #eef1ea; font-weight: 600; }
.q-table tr:last-child td { border-bottom: none; }
.q-table a { color: var(--accent); text-decoration: none; font-weight: 600; }
.q-table a:hover { text-decoration: underline; }

.badge {
  display: inline-block;
  background: var(--accent-bg);
  color: var(--accent);
  border-radius: 5px;
  padding: 2px 7px;
  font-size: 0.78em;
  margin: 2px 3px 2px 0;
  white-space: nowrap;
}
.badge-task { background: #e5eef7; color: #2b5f8a; }
.badge-grouped { background: #f2ecf7; color: #6a4b8a; }

.status { font-size: 0.85em; font-weight: 600; }
.status-ok { color: var(--ok); }
.status-pending { color: var(--pending); }

.pager {
  display: flex;
  justify-content: center;
  gap: 20px;
  margin-top: 20px;
  align-items: center;
}
.pager a { color: var(--accent); text-decoration: none; font-weight: 600; }

.back-link { display: inline-block; margin-bottom: 14px; color: var(--accent); text-decoration: none; }

.detail-header h1 { margin-bottom: 6px; }
.detail-badges { margin-bottom: 18px; }

.problem-card, .answer-card, .solution-card, .verify-card, .meta-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 18px 20px;
  margin-bottom: 16px;
}
.problem-card img { max-width: 100%; height: auto; }
.problem-card table { border-collapse: collapse; }
.problem-card td { padding: 4px 8px; }

.answer-verified { border-color: var(--ok); background: var(--ok-bg); }
.answer-pending { border-color: var(--pending); background: var(--pending-bg); }
.answer-card h2 { margin: 0 0 8px; font-size: 1em; }
.final-answer { font-size: 1.6em; font-weight: 700; margin: 0 0 6px; }
.answer-meta { font-size: 0.8em; color: var(--text-muted); margin: 0; }

.solution-card h2 { font-size: 1em; margin-top: 0; }
.solution-steps { padding-left: 20px; }
.solution-steps li { margin-bottom: 6px; }

.verify-link {
  display: inline-block;
  background: var(--accent);
  color: white;
  text-decoration: none;
  padding: 9px 16px;
  border-radius: 6px;
  font-weight: 600;
  font-size: 0.9em;
}
.verify-note { color: var(--text-muted); font-size: 0.82em; margin: 8px 0 0; }

.meta-card table { width: 100%; }
.meta-card td { padding: 4px 8px; font-size: 0.85em; }
.meta-card td:first-child { color: var(--text-muted); width: 160px; }

.methodology { background: var(--card-bg); border: 1px solid var(--border); border-radius: 10px; padding: 20px 28px; }
.methodology table { border-collapse: collapse; width: 100%; margin: 12px 0; }
.methodology th, .methodology td { border: 1px solid var(--border); padding: 6px 10px; font-size: 0.85em; text-align: left; }
.methodology th { background: #eef1ea; }
.methodology code { background: #eef1ea; padding: 1px 5px; border-radius: 4px; }

@media (max-width: 640px) {
  .filters { flex-direction: column; align-items: stretch; }
  .filter-field select, .filter-field input { min-width: 0; width: 100%; }
  .q-table { display: block; overflow-x: auto; }
}