/* Knowledge graph + learning module styles. */

.type-kicker {
  display: inline-flex; align-items: center; gap: 8px; color: var(--faint);
  font-size: 11.5px; letter-spacing: 0.08em; text-transform: uppercase;
}
.knowledge-hero, .domain-hero {
  padding: 30px 30px 26px; margin: 6px 0 26px; border: 1px solid var(--border);
  border-radius: 16px; background:
    radial-gradient(1200px 220px at 8% -10%, color-mix(in srgb, var(--domain, var(--accent)) 16%, transparent), transparent 62%),
    var(--surface);
  box-shadow: var(--shadow-sm);
}
.domain-hero { border-left: 4px solid var(--domain, var(--accent)); }
.domain-kicker { color: var(--domain, var(--accent)); font: 700 11px/1.5 var(--font-sans); letter-spacing: 0.1em; text-transform: uppercase; }
.knowledge-hero h1, .domain-hero h1 { margin: 10px 0 10px; font-size: clamp(26px, 3.4vw, 36px); letter-spacing: -0.02em; }
.knowledge-hero .lede, .domain-hero .lede { max-width: 76ch; color: var(--text-soft); margin: 0 0 18px; }
.knowledge-stats, .domain-stats { display: flex; flex-wrap: wrap; gap: 10px; }
.knowledge-stats > div, .domain-stats > div {
  min-width: 112px; padding: 10px 14px; border: 1px solid var(--border); border-radius: 10px;
  background: var(--bg); display: flex; flex-direction: column; gap: 1px;
}
.knowledge-stats strong, .domain-stats strong { font-size: 21px; letter-spacing: -0.02em; font-variant-numeric: tabular-nums; }
.knowledge-stats span, .domain-stats span { font-size: 11px; color: var(--muted); }

.domain-essence { margin-top: 4px; }
.domain-essence h2 { margin-top: 6px; }
.domain-points, .domain-pitfalls { padding-left: 22px; }
.domain-points li, .domain-pitfalls li { margin: 6px 0; }
.domain-pitfalls li::marker { color: var(--amber); }
.domain-learn { margin-top: 18px; }
.button-link {
  display: inline-flex; align-items: center; gap: 6px; padding: 8px 14px; margin: 4px 10px 4px 0;
  border: 1px solid var(--border-strong); border-radius: 8px; background: var(--surface);
  color: var(--accent-text); font-size: 13px; font-weight: 600; text-decoration: none;
}
.button-link:hover { border-color: var(--accent); background: var(--accent-soft); text-decoration: none; }

.graph-section { margin: 30px 0; }
.graph-toolbar { display: flex; align-items: center; gap: 14px; flex-wrap: wrap; margin: 10px 0 12px; }
.graph-toolbar h2 { margin: 0; border: 0; padding: 0; }
.graph-filter {
  min-width: 220px; flex: 0 1 300px; padding: 8px 11px; border: 1px solid var(--border-strong);
  border-radius: 8px; background: var(--surface); color: var(--text); font: 400 13px var(--font-sans);
}
.graph-legend { display: inline-flex; align-items: center; gap: 6px; color: var(--muted); font-size: 12px; }
.graph-legend span { width: 10px; height: 10px; display: inline-block; }
.graph-legend .legend-python { background: #4f7cff; border-radius: 50%; }
.graph-legend .legend-java { background: #e07a3f; border-radius: 3px; margin-left: 10px; }
.graph-canvas {
  position: relative; width: 100%; height: 480px; border: 1px solid var(--border);
  border-radius: 14px; overflow: hidden; touch-action: none; cursor: grab;
  background:
    linear-gradient(var(--border) 1px, transparent 1px) 0 0 / 32px 32px,
    linear-gradient(90deg, var(--border) 1px, transparent 1px) 0 0 / 32px 32px,
    radial-gradient(700px 340px at 50% 18%, color-mix(in srgb, var(--accent) 7%, transparent), transparent 70%),
    var(--surface);
}
.graph-canvas canvas { display: block; }
html[data-theme="dark"] .graph-canvas { background-color: var(--surface); }

.api-section { margin: 32px 0; }
.api-section > h2 { display: flex; align-items: center; gap: 10px; }
.count-badge {
  display: inline-grid; place-items: center; min-width: 30px; padding: 1px 8px; border-radius: 999px;
  background: var(--accent-soft); color: var(--accent-text); font: 600 11.5px var(--font-mono);
}
.api-group { border: 1px solid var(--border); border-radius: 10px; margin: 10px 0; background: var(--surface); overflow: hidden; }
.api-group > summary {
  display: flex; align-items: center; gap: 10px; padding: 10px 14px; cursor: pointer;
  background: var(--surface-2); font-size: 12.5px; list-style: none;
}
.api-group > summary::-webkit-details-marker { display: none; }
.api-group > summary::before { content: "▸"; color: var(--faint); font-size: 11px; transition: transform 0.15s ease; }
.api-group[open] > summary::before { transform: rotate(90deg); }
.api-group > summary code { background: none; border: 0; padding: 0; font-size: 12.5px; }
.api-group > summary .count {
  margin-left: auto; color: var(--muted); font: 600 11px var(--font-mono);
  background: var(--bg); border: 1px solid var(--border); border-radius: 999px; padding: 1px 8px;
}
.api-group .api-table { margin: 0; border-radius: 0; }
.api-group .api-table td { padding: 7px 12px; }
.api-table .name-cell { width: 32%; }
.api-table .kind-cell { width: 10%; color: var(--faint); font-size: 11.5px; }
.api-table .artifact-cell { width: 18%; color: var(--muted); font-size: 11px; overflow-wrap: anywhere; }
.api-table .summary-cell { font-size: 12.5px; }
.api-chips { display: flex; flex-wrap: wrap; gap: 7px; margin: 8px 0 2px; }
.api-chip {
  display: inline-flex; align-items: center; padding: 4px 9px; border: 1px solid var(--border);
  border-radius: 999px; background: var(--surface); font-size: 12px;
}
.api-chip code { background: none; border: 0; padding: 0; font-size: 11.5px; color: inherit; }
.api-chip:hover { border-color: var(--accent); text-decoration: none; }
.api-chip.muted { color: var(--faint); }
.compare-columns { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.compare-columns h3 { margin-top: 0; }

.domain-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); gap: 14px; margin: 16px 0 26px; }
.domain-card {
  display: flex; flex-direction: column; gap: 6px; padding: 17px 18px; border: 1px solid var(--border);
  border-top: 3px solid var(--domain, var(--accent)); border-radius: 12px; background: var(--surface);
  color: var(--text); text-decoration: none; transition: transform 0.15s ease, box-shadow 0.15s ease;
}
.domain-card:hover { transform: translateY(-2px); box-shadow: var(--shadow-md); text-decoration: none; color: var(--text); }
.domain-card-head { display: flex; align-items: center; gap: 8px; }
.domain-card-head h3 { margin: 0; font-size: 15.5px; border: 0; padding: 0; }
.domain-card p { margin: 0; color: var(--muted); font-size: 12.5px; min-height: 2.6em; }
.domain-card-stats { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 4px; }
.domain-card-stats span { padding: 1px 8px; border-radius: 999px; background: var(--surface-2); color: var(--muted); font-size: 10.5px; font-family: var(--font-mono); }
.domain-dot { display: inline-block; width: 9px; height: 9px; border-radius: 50%; background: var(--dot, var(--accent)); flex: none; }
.domain-matrix .name-cell { width: 26%; }
.domain-matrix .num { width: 9%; }
.domain-steps li { margin: 6px 0; }
.knowledge-graph-canvas { height: 520px; }

.map-toolbar { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; margin: 14px 0; }
.map-toolbar input, .map-toolbar select {
  padding: 8px 11px; border: 1px solid var(--border-strong); border-radius: 8px;
  background: var(--surface); color: var(--text); font: 400 13px var(--font-sans);
}
.map-toolbar input { flex: 1 1 280px; max-width: 420px; }
.map-count { font: 600 12px var(--font-mono); color: var(--muted); }
.map-table-wrap { overflow-x: auto; border: 1px solid var(--border); border-radius: 10px; }
.api-map-table { min-width: 780px; }
.api-map-table .name-cell { width: 34%; }
.api-map-table .lang-cell { width: 8%; color: var(--muted); font-size: 11.5px; }
.api-map-table .kind-cell { width: 9%; }
.api-map-table .domain-cell { width: 16%; white-space: nowrap; }
.api-map-table .domain-cell a { display: inline-flex; align-items: center; gap: 6px; color: var(--text-soft); }
.api-map-table tr[hidden] { display: none; }

/* Learning module */
.learn-hero {
  padding: 30px; margin: 6px 0 24px; border: 1px solid var(--border); border-radius: 16px;
  background:
    radial-gradient(900px 240px at 88% -20%, color-mix(in srgb, var(--purple) 18%, transparent), transparent 65%),
    radial-gradient(700px 200px at 8% -30%, color-mix(in srgb, var(--accent) 16%, transparent), transparent 60%),
    var(--surface);
  box-shadow: var(--shadow-sm);
}
.learn-hero h1 { margin: 10px 0; font-size: clamp(27px, 3.6vw, 38px); letter-spacing: -0.02em; }
.learn-hero .lede { max-width: 76ch; color: var(--text-soft); }
.learn-stats { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 18px; }
.learn-stat { min-width: 118px; padding: 10px 14px; border: 1px solid var(--border); border-radius: 10px; background: var(--bg); }
.learn-stat strong { display: block; font-size: 22px; font-variant-numeric: tabular-nums; letter-spacing: -0.02em; }
.learn-stat span { font-size: 11px; color: var(--muted); }
.learn-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 18px; }

.path-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(290px, 1fr)); gap: 14px; margin: 16px 0 28px; }
.unit-card {
  position: relative; display: flex; flex-direction: column; gap: 7px; padding: 17px 18px;
  border: 1px solid var(--border); border-radius: 12px; background: var(--surface); color: var(--text);
  text-decoration: none; transition: transform 0.15s ease, box-shadow 0.15s ease, border-color 0.15s ease;
}
.unit-card:hover { transform: translateY(-2px); box-shadow: var(--shadow-md); border-color: var(--border-strong); text-decoration: none; color: var(--text); }
.unit-card.done { border-color: color-mix(in srgb, var(--green) 55%, var(--border)); }
.unit-index {
  position: absolute; top: 14px; right: 16px; font: 700 11px var(--font-mono); color: var(--faint);
  background: var(--surface-2); border: 1px solid var(--border); border-radius: 999px; padding: 1px 8px;
}
.unit-card h3 { margin: 0 34px 0 0; font-size: 15.5px; border: 0; padding: 0; }
.unit-card p { margin: 0; color: var(--muted); font-size: 12.5px; }
.unit-domain { display: inline-flex; align-items: center; gap: 6px; font-size: 11px; color: var(--faint); }
.unit-progress { margin-top: 4px; }
.progress-bar { height: 5px; border-radius: 999px; background: var(--bg-code); overflow: hidden; }
.progress-bar > i { display: block; height: 100%; border-radius: inherit; background: linear-gradient(90deg, var(--accent), var(--purple)); transition: width 0.25s ease; }
.progress-label { display: flex; justify-content: space-between; margin-top: 4px; font-size: 10.5px; color: var(--faint); font-family: var(--font-mono); }

.learn-layout { display: grid; grid-template-columns: minmax(0, 1fr); gap: 24px; }
.unit-header { padding: 24px 26px; border: 1px solid var(--border); border-radius: 14px; background: var(--surface); margin-bottom: 22px; }
.unit-header h1 { margin: 6px 0 8px; font-size: clamp(24px, 3vw, 32px); }
.unit-header .lede { color: var(--text-soft); margin: 0; }
.unit-meta { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 12px; }
.unit-meta span { padding: 2px 9px; border: 1px solid var(--border); border-radius: 999px; background: var(--surface-2); color: var(--muted); font-size: 11px; }
.lesson-section { margin: 26px 0; }
.lesson-section h2 { font-size: 20px; margin-bottom: 10px; }
.lesson-section h3 { font-size: 15.5px; }
.goal-list, .concept-list { padding-left: 22px; }
.goal-list li, .concept-list li { margin: 5px 0; color: var(--text-soft); }
.key-api-grid { display: flex; flex-wrap: wrap; gap: 8px; }
.key-api-grid a {
  display: inline-flex; flex-direction: column; gap: 2px; padding: 8px 12px; border: 1px solid var(--border);
  border-radius: 9px; background: var(--surface); color: var(--text); text-decoration: none; font-size: 12.5px;
}
.key-api-grid a:hover { border-color: var(--accent); background: var(--accent-soft); text-decoration: none; }
.key-api-grid a code { background: none; border: 0; padding: 0; color: var(--accent-text); font-size: 12px; }
.key-api-grid a span { color: var(--faint); font-size: 10.5px; }

.flashcard-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); gap: 12px; }
.flashcard {
  display: block; width: 100%; height: 168px; perspective: 900px; border: 0; padding: 0;
  background: none; color: inherit; font: inherit; cursor: pointer; text-align: left;
}
.flashcard-inner {
  display: block; position: relative; width: 100%; height: 100%;
  transition: transform 0.45s cubic-bezier(0.2, 0.7, 0.2, 1); transform-style: preserve-3d;
}
.flashcard.flipped .flashcard-inner { transform: rotateY(180deg); }
.flashcard-face {
  position: absolute; inset: 0; display: flex; flex-direction: column; justify-content: center; gap: 7px;
  padding: 15px 17px; border: 1px solid var(--border); border-radius: 12px; background: var(--surface);
  backface-visibility: hidden; -webkit-backface-visibility: hidden; box-shadow: var(--shadow-sm);
  overflow: hidden; transition: border-color 0.15s ease, box-shadow 0.15s ease;
}
.flashcard:hover .flashcard-face { border-color: var(--border-strong); box-shadow: var(--shadow-md); }
.flashcard-face strong { font-size: 13px; font-family: var(--font-mono); letter-spacing: -0.01em; }
.flashcard-face p { margin: 0; color: var(--muted); font-size: 11.8px; line-height: 1.5; }
.flashcard-face .fc-hint { position: absolute; right: 12px; bottom: 8px; font-size: 10px; color: var(--faint); }
.flashcard-back { transform: rotateY(180deg); background: linear-gradient(160deg, var(--accent-soft), var(--surface)); border-color: color-mix(in srgb, var(--accent) 40%, var(--border)); }
.flashcard-back strong { color: var(--accent-text); }

.quiz { display: flex; flex-direction: column; gap: 14px; }
.quiz-q { border: 1px solid var(--border); border-radius: 12px; padding: 16px 18px; background: var(--surface); }
.quiz-stem { display: flex; gap: 10px; font-weight: 600; font-size: 14px; margin-bottom: 10px; }
.quiz-stem .q-no { flex: none; color: var(--faint); font: 700 11px var(--font-mono); padding-top: 3px; }
.quiz-options { display: grid; gap: 7px; }
.quiz-option {
  display: flex; align-items: flex-start; gap: 9px; width: 100%; padding: 9px 12px; border: 1px solid var(--border);
  border-radius: 8px; background: var(--bg); color: var(--text-soft); font: 400 13px/1.55 var(--font-sans);
  text-align: left; cursor: pointer; transition: border-color 0.12s ease, background 0.12s ease;
}
.quiz-option:hover:not(:disabled) { border-color: var(--accent); background: var(--accent-soft); }
.quiz-option:disabled { cursor: default; }
.quiz-option .opt-key { flex: none; width: 20px; height: 20px; display: inline-grid; place-items: center; border-radius: 5px; background: var(--surface-2); border: 1px solid var(--border); font: 600 10.5px var(--font-mono); color: var(--muted); }
.quiz-option.correct { border-color: color-mix(in srgb, var(--green) 60%, var(--border)); background: var(--green-soft); color: var(--text); }
.quiz-option.correct .opt-key { background: var(--green); border-color: var(--green); color: #fff; }
.quiz-option.wrong { border-color: color-mix(in srgb, var(--red) 55%, var(--border)); background: var(--red-soft); color: var(--text); }
.quiz-option.wrong .opt-key { background: var(--red); border-color: var(--red); color: #fff; }
.quiz-option.selected { border-color: var(--accent); background: var(--accent-soft); color: var(--text); box-shadow: inset 0 0 0 1px var(--accent); }
.quiz-option.selected .opt-key { background: var(--accent); border-color: var(--accent); color: #fff; }
.quiz-q.mastered { border-color: color-mix(in srgb, var(--green) 45%, var(--border)); }
.quiz-explain { margin-top: 10px; padding: 10px 12px; border-left: 3px solid var(--accent); border-radius: 0 8px 8px 0; background: var(--accent-soft); font-size: 12.5px; color: var(--text-soft); }
.quiz-explain strong { color: var(--accent-text); }
.quiz-result { display: flex; align-items: center; gap: 12px; padding: 14px 16px; border: 1px solid var(--border); border-radius: 10px; background: var(--surface-2); font-size: 13px; }
.quiz-result strong { font-size: 18px; color: var(--accent-text); font-variant-numeric: tabular-nums; }
.quiz-result span { color: var(--text-soft); }
.unit-side-no { display: inline-block; min-width: 15px; margin-right: 5px; font: 600 9.5px var(--font-mono); color: var(--faint); }

.unit-nav { display: flex; justify-content: space-between; gap: 12px; margin: 30px 0; }
.unit-nav a { flex: 1; max-width: 48%; padding: 12px 14px; border: 1px solid var(--border); border-radius: 10px; background: var(--surface); text-decoration: none; color: var(--text); font-size: 12.5px; }
.unit-nav a:hover { border-color: var(--accent); text-decoration: none; }
.unit-nav a.next { text-align: right; margin-left: auto; }
.unit-nav small { display: block; color: var(--faint); font-size: 10.5px; margin-bottom: 2px; }

.scenario-toolbar { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; margin: 14px 0; }
.scenario-toolbar input, .scenario-toolbar select {
  padding: 8px 11px; border: 1px solid var(--border-strong); border-radius: 8px; background: var(--surface);
  color: var(--text); font: 400 13px var(--font-sans);
}
.scenario-toolbar input { flex: 1 1 260px; max-width: 380px; }
.scenario-list { display: flex; flex-direction: column; gap: 14px; }
.scenario[hidden] { display: none; }
.scenario { border: 1px solid var(--border); border-left: 4px solid var(--sev, var(--amber)); border-radius: 12px; background: var(--surface); overflow: hidden; }
.scenario[data-severity="P0"] { --sev: var(--red); }
.scenario[data-severity="P1"] { --sev: #d97706; }
.scenario[data-severity="P2"] { --sev: #2f7fb0; }
.scenario-head { display: flex; flex-wrap: wrap; align-items: center; gap: 9px; padding: 14px 18px; background: var(--surface-2); }
.scenario-head h3 { margin: 0; font-size: 15.5px; border: 0; padding: 0; flex: 1 1 320px; }
.sev-badge { padding: 1px 8px; border-radius: 999px; background: color-mix(in srgb, var(--sev) 16%, transparent); color: var(--sev); font: 700 10px var(--font-mono); }
.scenario-tags { display: flex; flex-wrap: wrap; gap: 6px; }
.scenario-tags span { padding: 1px 7px; border: 1px solid var(--border); border-radius: 999px; color: var(--muted); font-size: 10.5px; background: var(--bg); }
.scenario-body { padding: 4px 18px 16px; }
.scenario-block { margin: 12px 0; }
.scenario-block > h4 { margin: 0 0 4px; font-size: 12px; color: var(--faint); letter-spacing: 0.06em; text-transform: uppercase; }
.scenario-block p, .scenario-block li { color: var(--text-soft); font-size: 13px; }
.scenario-block ul, .scenario-block ol { margin: 0; padding-left: 20px; }
.scenario-code { margin: 8px 0 0; padding: 10px 12px; border: 1px solid var(--border); border-radius: 8px; background: var(--bg-code); overflow-x: auto; }
.scenario-code code { background: none; border: 0; padding: 0; font-size: 11.5px; }
.scenario-api { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 10px; }

.exam-toolbar { display: flex; flex-wrap: wrap; align-items: center; gap: 12px; padding: 14px 16px; border: 1px solid var(--border); border-radius: 12px; background: var(--surface); margin: 16px 0; }
.exam-timer { font: 700 15px var(--font-mono); color: var(--accent-text); }
.exam-timer.low { color: var(--red); }
.exam-progress { color: var(--muted); font-size: 12.5px; }
.exam-submit { margin-left: auto; padding: 8px 18px; border: 1px solid var(--accent); border-radius: 8px; background: var(--accent); color: #fff; font: 600 13px var(--font-sans); cursor: pointer; }
.exam-submit:hover { background: var(--accent-hover); }
.exam-best { margin: -4px 0 14px; color: var(--muted); font-size: 12.5px; }
.exam-score { padding: 22px; border: 1px solid var(--border); border-radius: 12px; background: var(--surface); text-align: center; }
.exam-score strong { display: block; font-size: 38px; letter-spacing: -0.03em; color: var(--accent-text); }
.exam-score p { margin: 10px 0 0; color: var(--text-soft); }
.exam-score .exam-submit { display: inline-block; margin: 16px auto 0; }
.wrongbook-list { display: flex; flex-direction: column; gap: 10px; }
.wrong-item { padding: 14px 16px; border: 1px solid var(--border); border-radius: 10px; background: var(--surface); }
.wrong-item.mastered { border-color: color-mix(in srgb, var(--green) 55%, var(--border)); }
.wrong-item h3 { margin: 0 0 6px; font-size: 14px; border: 0; padding: 0; }
.wrong-item .wrong-meta { color: var(--faint); font-size: 11px; }
.wrong-item .quiz-options { margin-top: 8px; }
.wrong-item .wrong-answer { margin-top: 6px; font-size: 12.5px; }
.wrong-item .wrong-answer p { margin: 2px 0; color: var(--text-soft); }
.wrong-item .wrong-answer .ok { color: var(--green); }
.wrong-item .wrong-answer .bad { color: var(--red); }
.wrong-actions { display: flex; gap: 8px; margin-top: 8px; }
.wrong-actions button { padding: 4px 10px; border: 1px solid var(--border-strong); border-radius: 6px; background: var(--surface); color: var(--text-soft); font-size: 11.5px; cursor: pointer; }
.wrong-actions button:hover { border-color: var(--accent); color: var(--accent-text); }
.empty-state { padding: 34px 20px; text-align: center; color: var(--muted); border: 1px dashed var(--border-strong); border-radius: 12px; }

@media (max-width: 760px) {
  .compare-columns { grid-template-columns: 1fr; }
  .graph-canvas { height: 380px; }
  .knowledge-graph-canvas { height: 420px; }
  .unit-nav { flex-direction: column; }
  .unit-nav a, .unit-nav a.next { max-width: none; text-align: left; }
  .flashcard-grid { grid-template-columns: 1fr; }
}