/* ===== 문장나무 SentenceTree ===== */
* { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg: #f4f7fb;
  --card: #ffffff;
  --ink: #1e293b;
  --ink-soft: #64748b;
  --line: #dbe3ee;
  --accent: #2563eb;
  --accent-soft: #dbeafe;
  --warn-bg: #fff7ed;
  --warn-ink: #9a3412;
  --radius: 12px;
  --fs-base: 18px;
}

html, body { height: 100%; }
body {
  font-family: "Apple SD Gothic Neo", "Malgun Gothic", "Noto Sans KR",
               -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: var(--fs-base);
  background: var(--bg);
  color: var(--ink);
  display: flex;
  flex-direction: column;
}

button { font: inherit; cursor: pointer; }
input, select { font: inherit; }
.hidden { display: none !important; }

/* ===== 상단 바 ===== */
#topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
  padding: 10px 16px;
  background: var(--card);
  border-bottom: 2px solid var(--line);
}
.brand { font-size: 1.3em; font-weight: 800; white-space: nowrap; }
.topbar-controls { display: flex; align-items: center; flex-wrap: wrap; gap: 8px; }

.chip-btn, .icon-btn {
  border: 1.5px solid var(--line);
  background: var(--card);
  border-radius: 999px;
  padding: 8px 14px;
  font-size: 0.9em;
}
.chip-btn:hover, .icon-btn:hover { background: var(--accent-soft); }

.seg {
  display: inline-flex;
  align-items: center;
  border: 1.5px solid var(--line);
  border-radius: 999px;
  overflow: hidden;
  background: var(--card);
}
.seg-label { padding: 0 8px 0 12px; font-size: 0.8em; color: var(--ink-soft); }
.seg-btn {
  border: none;
  background: transparent;
  padding: 8px 14px;
  font-size: 0.9em;
  color: var(--ink-soft);
}
.seg-btn.active { background: var(--accent); color: #fff; font-weight: 700; }

/* ===== 메인 ===== */
#mainArea {
  flex: 1;
  display: flex;
  flex-direction: column;
  padding: 12px 16px 20px;
  gap: 10px;
  max-width: 1400px;
  width: 100%;
  margin: 0 auto;
}

/* 입력 영역 */
#inputArea {
  background: var(--card);
  border: 1.5px solid var(--line);
  border-radius: var(--radius);
  padding: 14px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.input-row { display: flex; gap: 8px; }
#sentenceInput {
  flex: 1;
  font-size: 1.1em;
  padding: 12px 16px;
  border: 2px solid var(--line);
  border-radius: var(--radius);
  min-width: 0;
}
#sentenceInput:focus { outline: none; border-color: var(--accent); }

.primary-btn {
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: var(--radius);
  padding: 12px 22px;
  font-size: 1.05em;
  font-weight: 700;
  white-space: nowrap;
}
.primary-btn:hover { filter: brightness(1.1); }
.primary-btn.small { padding: 8px 16px; font-size: 0.95em; }

.chips { display: flex; flex-wrap: wrap; gap: 8px; }
.chips .chip {
  border: 1.5px dashed var(--line);
  background: #f8fafc;
  border-radius: 999px;
  padding: 7px 14px;
  font-size: 0.9em;
  color: var(--ink);
}
.chips .chip:hover { background: var(--accent-soft); border-style: solid; }
.chips .more-chip {
  border-style: solid;
  border-color: var(--accent);
  color: var(--accent);
  font-weight: 700;
  background: var(--accent-soft);
}

.mode-row { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; }
.tool-btn {
  border: 1.5px solid var(--line);
  background: #f8fafc;
  border-radius: 10px;
  padding: 8px 14px;
  font-size: 0.9em;
}
.tool-btn:hover { background: var(--accent-soft); }
.tool-btn.active { background: var(--accent); color: #fff; border-color: var(--accent); }
.ai-btn { border-color: #c4b5fd; background: #f5f3ff; }
.ai-btn:hover { background: #ede9fe; }
.compare { font-size: 0.9em; display: inline-flex; align-items: center; gap: 6px; }

/* 학습 도우미 바 */
#helperBar { display: flex; flex-wrap: wrap; gap: 10px; }
.helper-item { flex: 1; min-width: 260px; }
.helper-btn {
  width: 100%;
  text-align: left;
  border: 1.5px solid var(--line);
  background: var(--card);
  border-radius: var(--radius);
  padding: 10px 14px;
  font-size: 0.95em;
  font-weight: 600;
}
.helper-btn:hover { background: var(--accent-soft); }
.helper-box {
  margin-top: 6px;
  background: var(--card);
  border: 1.5px solid var(--line);
  border-radius: var(--radius);
  padding: 12px 14px;
  font-size: 0.95em;
  line-height: 1.6;
  white-space: pre-wrap;
}

/* ===== 트리 영역 ===== */
#treeArea {
  position: relative;
  background: var(--card);
  border: 1.5px solid var(--line);
  border-radius: var(--radius);
  min-height: 55vh;
  overflow: hidden;
  flex: 1;
}
#treeSvg { width: 100%; height: 100%; min-height: 55vh; display: block; touch-action: none; }

.tree-empty {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--ink-soft);
  font-size: 1.2em;
  pointer-events: none;
  text-align: center;
  padding: 20px;
}

.legend {
  position: absolute;
  top: 10px;
  right: 10px;
  background: rgba(255, 255, 255, 0.95);
  border: 1.5px solid var(--line);
  border-radius: 10px;
  padding: 10px 12px;
  font-size: 0.82em;
  display: flex;
  flex-direction: column;
  gap: 5px;
  max-width: 180px;
}
.legend .lg-row { display: flex; align-items: center; gap: 7px; }
.legend .lg-dot { width: 14px; height: 14px; border-radius: 4px; flex: none; }

.step-controls {
  position: absolute;
  bottom: 12px;
  left: 12px;
  display: flex;
  align-items: center;
  gap: 10px;
  background: rgba(255, 255, 255, 0.95);
  border: 1.5px solid var(--line);
  border-radius: 10px;
  padding: 8px 12px;
  font-size: 0.9em;
}

.popover {
  position: absolute;
  z-index: 30;
  background: #1e293b;
  color: #f8fafc;
  border-radius: 10px;
  padding: 10px 14px;
  font-size: 0.9em;
  max-width: 300px;
  line-height: 1.5;
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.25);
}
.popover .pop-word { font-weight: 800; font-size: 1.1em; }
.popover .pop-roman { color: #93c5fd; font-size: 0.85em; }
.popover .pop-meaning { margin-top: 4px; white-space: pre-wrap; }

/* SVG 노드 */
.node { cursor: grab; }
.node:active { cursor: grabbing; }
.node rect { transition: opacity 0.25s; }
.node-appear { animation: nodePop 0.35s ease-out; }
@keyframes nodePop {
  from { opacity: 0; }
  to { opacity: 1; }
}

/* ===== 연습 패널 ===== */
.practice-panel {
  background: var(--card);
  border: 2px solid var(--accent);
  border-radius: var(--radius);
  padding: 14px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.practice-head { display: flex; justify-content: space-between; align-items: center; }
.practice-actions { display: flex; gap: 8px; }

.order-cards {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  min-height: 64px;
  padding: 10px;
  background: #f8fafc;
  border: 2px dashed var(--line);
  border-radius: var(--radius);
}
.order-card {
  background: var(--card);
  border: 2px solid var(--accent);
  border-radius: 10px;
  padding: 12px 18px;
  font-size: 1.15em;
  font-weight: 700;
  cursor: grab;
  user-select: none;
  touch-action: none;
}
.order-card.selected { background: var(--accent); color: #fff; }
.order-card.dragging { opacity: 0.5; }
.order-card.correct { border-color: #16a34a; background: #dcfce7; }
.order-card.wrong { border-color: #dc2626; background: #fee2e2; }

#quizChoices .chip { font-size: 1em; padding: 10px 18px; font-weight: 700; }

/* ===== AI 패널 ===== */
#aiPanel {
  background: var(--card);
  border: 1.5px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}
.ai-panel-toggle {
  width: 100%;
  text-align: left;
  border: none;
  background: linear-gradient(90deg, #eef2ff, #faf5ff);
  padding: 12px 16px;
  font-size: 1.05em;
  font-weight: 700;
}
.ai-panel-body { padding: 14px; display: flex; flex-direction: column; gap: 10px; }
.ai-quick-btns { display: flex; flex-wrap: wrap; gap: 8px; }
.ai-output {
  min-height: 40px;
  background: #f8fafc;
  border: 1.5px solid var(--line);
  border-radius: 10px;
  padding: 12px 14px;
  font-size: 0.95em;
  line-height: 1.65;
  white-space: pre-wrap;
}
.ai-output:empty { display: none; }
.ai-output .quiz-q { margin-bottom: 10px; }
.ai-output .quiz-choice {
  display: block;
  margin: 4px 0;
  padding: 8px 12px;
  border: 1.5px solid var(--line);
  border-radius: 8px;
  background: var(--card);
  width: 100%;
  text-align: left;
}
.ai-output .quiz-choice.correct { background: #dcfce7; border-color: #16a34a; }
.ai-output .quiz-choice.wrong { background: #fee2e2; border-color: #dc2626; }
.ai-ask-row { display: flex; gap: 8px; }
#aiAskInput {
  flex: 1;
  padding: 10px 14px;
  border: 1.5px solid var(--line);
  border-radius: 10px;
  min-width: 0;
}
.fine-print { font-size: 0.78em; color: var(--ink-soft); }
.warn-note {
  background: var(--warn-bg);
  color: var(--warn-ink);
  border-radius: 10px;
  padding: 10px 12px;
  font-size: 0.88em;
  line-height: 1.5;
}

/* ===== 모달 ===== */
.modal {
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
  padding: 16px;
}
.modal-card {
  background: var(--card);
  border-radius: 16px;
  padding: 22px;
  width: min(520px, 100%);
  max-height: 85vh;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.modal-card h2 { font-size: 1.2em; }
.field { display: flex; flex-direction: column; gap: 6px; font-weight: 600; }
.field input, .field select {
  padding: 10px 14px;
  border: 1.5px solid var(--line);
  border-radius: 10px;
  font-weight: 400;
}
.modal-actions { display: flex; gap: 8px; justify-content: flex-end; }

.lib-save-row { display: flex; gap: 8px; }
#libNameInput {
  flex: 1;
  padding: 10px 14px;
  border: 1.5px solid var(--line);
  border-radius: 10px;
  min-width: 0;
}
.lib-list { list-style: none; display: flex; flex-direction: column; gap: 8px; }
.lib-list li {
  display: flex;
  align-items: center;
  gap: 8px;
  border: 1.5px solid var(--line);
  border-radius: 10px;
  padding: 10px 12px;
}
.lib-list .lib-info { flex: 1; min-width: 0; }
.lib-list .lib-name { font-weight: 700; }
.lib-list .lib-sentence {
  font-size: 0.85em;
  color: var(--ink-soft);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.lib-empty { color: var(--ink-soft); text-align: center; padding: 16px; }

/* ===== 수업(발표) 모드 ===== */
body.presentation { --fs-base: 24px; }
body.presentation #topbar { padding: 14px 20px; }
body.presentation #treeArea { min-height: 65vh; }
body.presentation #helperBar,
body.presentation .chips { font-size: 1.05em; }
body.presentation {
  --ink: #0f172a;
  --line: #94a3b8;
}

/* ===== 반응형 ===== */
@media (max-width: 760px) {
  :root { --fs-base: 16px; }
  #topbar { justify-content: center; }
  .input-row { flex-direction: column; }
  .legend { position: static; max-width: none; flex-direction: row; flex-wrap: wrap; margin: 8px; }
  #treeArea { min-height: 45vh; }
}