:root {
  --bg: #f7f8fb;
  --panel: #ffffff;
  --text: #20232a;
  --muted: #5f6775;
  --border: #d9dde7;
  --accent: #1f6feb;
  --correct-bg: #e9f8ee;
  --correct-border: #2f8f46;
  --wrong-bg: #fff0f0;
  --wrong-border: #c73a3a;
  --anchor-bg: #eff5ff;
}

* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: Inter, system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
}

.app-shell { min-height: 100vh; }
.topbar {
  border-bottom: 1px solid var(--border);
  background: var(--panel);
  padding: 1rem 1.25rem;
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  align-items: center;
}
.topbar h1 { margin: 0; font-size: 1.2rem; }

.layout {
  display: grid;
  grid-template-columns: 260px minmax(0, 1fr);
  min-height: calc(100vh - 72px);
}

.sidebar {
  border-right: 1px solid var(--border);
  background: var(--panel);
  padding: 0.75rem;
  display: grid;
  gap: 0.5rem;
  align-content: start;
}
.sidebar button {
  text-align: left;
  border: 1px solid var(--border);
  background: #fff;
  padding: 0.55rem 0.65rem;
  border-radius: 0.5rem;
  cursor: pointer;
}
.sidebar button.active,
.sidebar button:hover,
button.primary {
  border-color: var(--accent);
  color: var(--accent);
}

.content {
  padding: 1rem;
  max-width: 1200px;
}
.card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1rem;
  margin-bottom: 1rem;
}

.domain-header { display: flex; align-items: center; gap: 0.8rem; }
.badge {
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 0.15rem 0.6rem;
  font-size: 0.82rem;
  color: var(--muted);
}
.anchor-box {
  border: 1px solid #bcd2ff;
  background: var(--anchor-bg);
  border-radius: 10px;
  padding: 0.8rem;
}
.small { color: var(--muted); font-size: 0.9rem; }

label, select, button, input { font: inherit; }
input[type="url"] {
  width: 100%;
  padding: 0.45rem 0.5rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  margin-top: 0.25rem;
}

.quiz-header { display: flex; flex-wrap: wrap; gap: 0.55rem; align-items: center; }
.quiz-progress {
  width: 100%;
  height: 12px;
  background: #eef1f5;
  border-radius: 999px;
  overflow: hidden;
}
.quiz-progress > span { display: block; height: 100%; background: var(--accent); }

.filters {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(170px, 1fr));
  gap: 0.75rem;
}
.choice {
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 0.6rem;
  display: block;
  cursor: pointer;
}
.choice.correct { background: var(--correct-bg); border-color: var(--correct-border); }
.choice.incorrect { background: var(--wrong-bg); border-color: var(--wrong-border); }
.choice:focus-within { outline: 2px solid var(--accent); }

.feedback { margin-top: 0.8rem; padding: 0.7rem; border-radius: 8px; }
.feedback.good { background: var(--correct-bg); border: 1px solid var(--correct-border); }
.feedback.bad { background: var(--wrong-bg); border: 1px solid var(--wrong-border); }

.stats-pills { display: flex; gap: 0.5rem; flex-wrap: wrap; }
.actions-row { display: flex; gap: 0.6rem; flex-wrap: wrap; }
.bridge-panel {
  border: 1px dashed var(--border);
  border-radius: 10px;
  padding: 0.8rem;
  margin: 0.9rem 0;
  display: grid;
  gap: 0.6rem;
}

.sticky-actions {
  position: sticky;
  bottom: 0;
  background: linear-gradient(transparent, #fff 30%);
  padding-top: 0.6rem;
}

@media (max-width: 900px) {
  .layout { grid-template-columns: 1fr; }
  .sidebar {
    border-right: none;
    border-bottom: 1px solid var(--border);
    grid-template-columns: repeat(auto-fit, minmax(170px, 1fr));
  }
}

@media (max-width: 640px) {
  .topbar {
    padding: 0.8rem;
    align-items: flex-start;
    flex-direction: column;
  }

  .sidebar button,
  .actions-row button,
  .sticky-actions button {
    min-height: 44px;
  }

  .content {
    padding: 0.75rem;
  }
}

.verbatim-guide {
  white-space: pre-wrap;
  line-height: 1.45;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1rem;
  background: #fbfcfe;
  max-height: 70vh;
  overflow: auto;
}

.markdown-guide {
  line-height: 1.55;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1rem;
  background: #fbfcfe;
  overflow: auto;
}

.markdown-guide h1,
.markdown-guide h2,
.markdown-guide h3,
.markdown-guide h4,
.markdown-guide h5,
.markdown-guide h6 {
  margin: 1rem 0 0.6rem;
}

.markdown-guide h1:first-child,
.markdown-guide h2:first-child,
.markdown-guide h3:first-child {
  margin-top: 0;
}

.markdown-guide p,
.markdown-guide ul,
.markdown-guide ol,
.markdown-guide pre {
  margin: 0.65rem 0;
}

.markdown-guide code {
  background: #eef2f8;
  border: 1px solid #dfe6f2;
  border-radius: 4px;
  padding: 0.05rem 0.3rem;
}

.markdown-guide pre {
  background: #f3f6fb;
  border: 1px solid #dfe6f2;
  border-radius: 8px;
  padding: 0.7rem;
}

.markdown-guide pre code {
  background: transparent;
  border: none;
  padding: 0;
}