:root {
  --bg: #0b1020;
  --card: #121a33;
  --ink: #e8ecff;
  --muted: #9aa6cf;
  --accent: #4ea1ff;
  --good: #30d158;
  --bad: #ff453a;
  --warn: #ff9f0a;
}

* { box-sizing: border-box; }
body {
  margin: 0; padding: 24px;
  font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Noto Sans", "Helvetica Neue", Arial, "Apple Color Emoji","Segoe UI Emoji";
  color: var(--ink);
  background: radial-gradient(1200px 600px at 10% -10%, #18234c 0, transparent 60%), var(--bg);
}
h1, h2 { margin: 0 0 12px; }
header, section, footer {
  background: color-mix(in oklab, var(--card), black 12%);
  border: 1px solid color-mix(in oklab, var(--card), white 10%);
  border-radius: 16px;
  padding: 16px 16px;
  margin-bottom: 16px;
  box-shadow: 0 6px 18px rgba(0,0,0,0.25);
}
.note { color: var(--muted); margin: 8px 0 0; }
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 12px;
}
label { display: flex; flex-direction: column; gap: 6px; }
input[type="text"], input[type="password"], input[type="number"], select, input[type="file"], textarea {
  background: #0f1630;
  border: 1px solid #2b3a6b;
  color: var(--ink);
  padding: 10px 12px;
  border-radius: 10px;
}
textarea {
  font-family: ui-monospace, "SF Mono", "Monaco", "Inconsolata", "Roboto Mono", monospace;
  font-size: 13px;
  line-height: 1.4;
  resize: vertical;
}
.checkbox { flex-direction: row; align-items: center; gap: 8px; }

.actions, .actions-inline { display: flex; gap: 10px; align-items: center; }
.actions, .actions-inline { flex-wrap: wrap; }
.actions-inline { margin-top: 8px; }
.no-top-margin { margin-top: 0; }

.learning-range {
  margin-top: 16px;
  padding-top: 16px;
  border-top: 1px solid #2b3a6b;
}
.learning-range h3 { margin: 0 0 6px; }
.learning-range .actions { margin-top: 12px; align-items: flex-end; }
.learning-range label { min-width: 130px; }

button {
  border: 1px solid #2b3a6b;
  background: linear-gradient(180deg, #1a2450, #121a33);
  color: var(--ink);
  padding: 10px 14px;
  border-radius: 10px;
  cursor: pointer;
}
button:hover { border-color: var(--accent); }
button.danger { border-color: var(--bad); color: #ffdada; }
button.secondary { opacity: .8; }

.status { color: var(--muted); }
.sync .status { word-break: break-word; }

.sync .actions input[type="email"],
.sync .actions input[type="password"] {
  flex: 1 1 180px;
  min-width: 0;
}

.sync .actions #loginInfo,
.sync .actions #loginStatus {
  flex: 1 1 100%;
}

.admin-vocabulary-pdf {
  margin-top: 16px;
  padding-top: 16px;
  border-top: 1px solid #2b3a6b;
}
.admin-vocabulary-pdf h3 { margin: 0 0 8px; }
.admin-vocabulary-pdf .actions { margin-top: 12px; align-items: flex-end; }
.admin-vocabulary-pdf label { min-width: 180px; }
.admin-vocabulary-pdf #adminVocabularyPdfStatus { flex: 1 1 100%; }

.backend-pdf-preview-modal {
  position: fixed;
  inset: 0;
  z-index: 2100;
  display: grid;
  place-items: center;
  padding: 24px;
}
.backend-pdf-preview-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(3, 7, 18, .82);
}
.backend-pdf-preview-content {
  position: relative;
  width: min(1100px, 96vw);
  height: min(92vh, 1000px);
  display: flex;
  flex-direction: column;
  padding: 16px;
  border: 1px solid #2b3a6b;
  border-radius: 16px;
  background: #0b1020;
  box-shadow: 0 20px 60px rgba(0, 0, 0, .55);
}
.backend-pdf-preview-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.backend-pdf-preview-header h3 { margin: 0; }
.backend-pdf-preview-close {
  padding: 4px 12px;
  font-size: 24px;
  line-height: 1;
}
.backend-pdf-preview-scroll {
  flex: 1;
  min-height: 0;
  margin-top: 12px;
  overflow: auto;
  border-radius: 10px;
  background: #202020;
  text-align: center;
}
.backend-pdf-preview-scroll img {
  display: block;
  width: auto;
  max-width: 100%;
  margin: 0 auto;
  background: white;
}

.hidden { display: none !important; }
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

table { width: 100%; border-collapse: collapse; }
thead th {
  text-align: left;
  font-weight: 600;
  color: var(--muted);
  border-bottom: 1px solid #2b3a6b;
  padding: 8px;
}
tbody td {
  padding: 8px;
  border-bottom: 1px dashed #2b3a6b;
}

.kanji-jump {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 1em;
  border-radius: 4px;
  cursor: pointer;
  isolation: isolate;
}

.kanji-jump:hover,
.kanji-jump:focus-visible {
  background: rgba(78, 161, 255, .18);
  outline: 1px solid rgba(78, 161, 255, .55);
}

.kanji-jump-controls {
  position: absolute;
  left: 50%;
  top: 50%;
  z-index: 20;
  display: none;
  flex-direction: column;
  align-items: center;
  gap: 24px;
  transform: translate(-50%, -50%);
  pointer-events: none;
}

.kanji-jump:hover .kanji-jump-controls,
.kanji-jump:focus-within .kanji-jump-controls {
  display: flex;
}

.kanji-jump.kanji-jump-controls-hidden .kanji-jump-controls {
  display: none;
}

.kanji-jump-btn {
  min-width: 46px;
  max-width: 76px;
  padding: 3px 6px;
  border-radius: 6px;
  border-color: rgba(120, 157, 255, .75);
  background: #101936;
  color: var(--ink);
  font-size: 11px;
  line-height: 1.2;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  pointer-events: auto;
  box-shadow: 0 4px 12px rgba(0, 0, 0, .28);
}

.kanji-jump-btn:disabled {
  opacity: .45;
  cursor: default;
}

.kanji-search-popup {
  position: fixed;
  z-index: 1000;
  display: flex;
  flex-direction: column;
  min-width: 360px;
  min-height: 320px;
  max-width: calc(100vw - 16px);
  max-height: calc(100vh - 16px);
  margin: 0;
  padding: 0;
  overflow: hidden;
  resize: none;
  border-radius: 10px;
  border: 1px solid #2b3a6b;
  background: #10172d;
  box-shadow: 0 18px 48px rgba(0, 0, 0, .48);
}

.kanji-search-popup-resize {
  position: absolute;
  right: 0;
  bottom: 0;
  width: 18px;
  height: 18px;
  cursor: nwse-resize;
  z-index: 3;
}

.kanji-search-popup-resize::after {
  content: "";
  position: absolute;
  right: 4px;
  bottom: 4px;
  width: 9px;
  height: 9px;
  border-right: 2px solid rgba(154, 166, 207, .85);
  border-bottom: 2px solid rgba(154, 166, 207, .85);
}

.kanji-search-popup-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 10px 12px;
  border-bottom: 1px solid #2b3a6b;
  background: #151f3d;
  cursor: move;
  user-select: none;
}

.kanji-search-popup-navigation {
  display: flex;
  flex: 0 0 auto;
  gap: 4px;
}

.kanji-search-popup-nav-btn {
  width: 28px;
  height: 28px;
  padding: 0;
  border-radius: 6px;
  font-size: 17px;
  line-height: 1;
}

.kanji-search-popup-nav-btn:disabled {
  opacity: .4;
  cursor: default;
}

.kanji-search-popup-title {
  flex: 1;
  min-width: 0;
  font-weight: 700;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.kanji-search-popup-close {
  width: 28px;
  height: 28px;
  padding: 0;
  border-radius: 6px;
  font-size: 18px;
  line-height: 1;
}

.kanji-search-popup-meta {
  padding: 8px 12px;
  color: var(--muted);
  font-size: 12px;
  line-height: 1.45;
  border-bottom: 1px solid rgba(43, 58, 107, .75);
}

.kanji-search-popup-body {
  flex: 1;
  min-height: 0;
  overflow: auto;
}

.kanji-search-popup-empty {
  padding: 18px 12px;
  color: var(--muted);
}

.kanji-search-result-table {
  font-size: 13px;
  table-layout: fixed;
}

.kanji-search-result-table th,
.kanji-search-result-table td {
  padding: 7px 8px;
  vertical-align: top;
  word-break: break-word;
}

.kanji-search-result-table th:first-child,
.kanji-search-result-table td:first-child {
  width: 64px;
}

.kanji-search-result-table th:nth-child(2),
.kanji-search-result-table td:nth-child(2) {
  width: 96px;
}

.kanji-search-result-table th:nth-child(3),
.kanji-search-result-table td:nth-child(3) {
  width: 112px;
}

.kanji-result-page-link {
  padding: 4px 6px;
  border-radius: 6px;
  font-size: 12px;
}

.kanji-result-preview-btn {
  margin-left: 4px;
  padding: 4px 6px;
  border-radius: 6px;
  font-size: 12px;
}

.kanji-result-mark {
  padding: 1px 2px;
  border-radius: 3px;
  color: #07101f;
}

.kanji-result-mark-pinyin {
  background: #ffd166;
}

.kanji-result-mark-kana,
.kanji-result-mark-reading {
  background: #7ae7c7;
}

.kanji-result-mark-kana-rendaku {
  background: #a9d7ff;
}

.kanji-result-mark-reading-rendaku {
  background: #a9d7ff;
}

.kanji-result-mark-pinyin-soft {
  background: rgba(255, 209, 102, .5);
  color: var(--ink);
}

.quick-memory-cell {
  min-width: 120px;
  max-width: 240px;
  white-space: normal;
  word-break: break-word;
  line-height: 1.5;
}

.section-heading {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: flex-start;
}

.word-association-row td {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.6;
  padding: 8px 8px 10px 44px;
  background: rgba(74, 163, 255, .055);
  border-bottom: 1px dashed #2b3a6b;
}

.word-association-content {
  max-width: min(760px, 78%);
  margin-left: auto;
  text-align: right;
}

.word-association-review-row td {
  color: var(--ink);
  line-height: 1.7;
  padding: 12px;
  background: rgba(255, 255, 255, .035);
  border-left: 3px solid var(--accent);
}

.quiz-panel.hidden { display: none; }

/* 测验面板布局 */
.quiz-panel {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.quiz-header {
  text-align: center;
}

.quiz-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  max-width: 600px;
  margin: 0 auto;
  padding: 20px;
  background: color-mix(in oklab, var(--card), black 8%);
  border-radius: 12px;
  border: 1px solid color-mix(in oklab, var(--card), white 5%);
}

.quiz-q { 
  font-size: 20px; 
  text-align: center;
  font-weight: 500;
  line-height: 1.4;
}

.hint { 
  color: var(--muted); 
  text-align: center;
  font-size: 14px;
  margin-top: 8px;
}

.quiz-a {
  display: flex;
  gap: 12px;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
}

.quiz-a input {
  min-width: 200px;
  text-align: center;
  font-size: 16px;
}

.result { 
  margin-top: 12px; 
  min-height: 24px; 
  text-align: center;
  font-weight: 500;
}

.good { color: var(--good); }
.bad { color: var(--bad); }
.warn { color: var(--warn); }

/* 答题记录样式 */
.quiz-results {
  max-width: 800px;
  margin: 0 auto;
}

.quiz-results h3 {
  margin: 0 0 12px;
  color: var(--muted);
  font-size: 16px;
  text-align: center;
}

.quiz-history {
  max-height: 200px;
  overflow-y: auto;
  background: color-mix(in oklab, var(--card), black 8%);
  border-radius: 8px;
  border: 1px solid color-mix(in oklab, var(--card), white 5%);
}

.quiz-history-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 8px 12px;
  border-bottom: 1px dashed #2b3a6b;
  font-size: 14px;
}

.quiz-history-item:last-child {
  border-bottom: none;
}

.quiz-history-item .question {
  flex: 1;
  color: var(--ink);
}

.quiz-history-item .answer {
  flex: 1;
  color: var(--muted);
}

.quiz-history-item .result {
  flex: 0 0 auto;
  font-weight: 500;
  min-width: 60px;
  text-align: center;
}

.quiz-history-item.correct .result {
  color: var(--good);
}

.pdf-preview {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 0;
  border: none;
  background: transparent;
}

.pdf-preview-info {
  font-size: 12px;
  color: var(--muted);
}

.pdf-preview-info:empty {
  display: none;
}

.pdf-preview-container {
  min-height: 30px;
}

.pdf-preview-container.has-thumb {
  width: 30px;
}

.pdf-preview-container:not(.has-thumb) {
  width: auto;
}

.pdf-preview-message {
  color: var(--muted);
  font-size: 13px;
  padding: 0;
  display: inline-block;
}

.pdf-preview-thumb {
  width: 30px;
  border-radius: 4px;
  border: none;
  overflow: hidden;
  cursor: pointer;
  background: transparent;
  display: block;
  transition: transform 0.2s ease;
}

.pdf-preview-thumb img {
  width: 100%;
  height: auto;
  display: block;
}

.pdf-preview-thumb.active {
  transform: scale(1.05);
}

.pdf-preview-thumb:hover {
  transform: scale(1.08);
}

.page-link,
.page-preview-btn {
  background: transparent;
  border: none;
  color: var(--accent);
  cursor: pointer;
  font-size: 13px;
  padding: 0 4px 0 0;
}

.page-link:hover {
  text-decoration: underline;
}

.page-preview-btn {
  color: var(--muted);
  padding-left: 2px;
}

.page-preview-btn:hover {
  color: var(--accent);
}

.pdf-modal {
  position: fixed;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
}

.pdf-modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.7);
}

.pdf-modal-content {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  max-width: 90%;
  max-height: 90%;
  background: #0f1630;
  border-radius: 12px;
  padding: 16px;
  border: 1px solid #2b3a6b;
  overflow: auto;
  cursor: default;
}

.pdf-modal-viewer {
  width: 100%;
  display: flex;
  flex-direction: column;
  gap: 12px;
  align-items: center;
}

.pdf-modal-canvas-wrapper {
  position: relative;
  width: 100%;
}

.pdf-modal-canvas-wrapper canvas {
  width: 100%;
  height: auto;
  display: block;
  background: #fff;
  border-radius: 4px;
}

.textLayer {
  position: absolute;
  inset: 0;
  overflow: hidden;
  opacity: 1;
  line-height: 1;
  pointer-events: none;
}

.textLayer > span {
  position: absolute;
  transform-origin: 0 0;
  white-space: pre;
  cursor: text;
  color: transparent;
  text-shadow: none;
  pointer-events: all;
  user-select: text;
  -webkit-user-select: text;
}

.textLayer > span::selection {
  background: rgba(77, 140, 255, 0.35);
}

.textLayer > span::-moz-selection {
  background: rgba(77, 140, 255, 0.35);
}

.pdf-modal-loading {
  font-size: 14px;
  color: var(--muted);
  width: 100%;
  text-align: center;
}

.pdf-modal-resize-handle {
  position: absolute;
  width: 16px;
  height: 16px;
  border: 2px solid rgba(117, 150, 255, 0.6);
  background: rgba(17, 27, 52, 0.9);
  border-radius: 6px;
  box-shadow: 0 0 6px rgba(35, 82, 210, 0.3);
  z-index: 5;
  pointer-events: auto;
}

.pdf-modal-resize-handle-nw {
  top: 6px;
  left: 6px;
  cursor: nwse-resize;
}

.pdf-modal-resize-handle-ne {
  top: 6px;
  right: 6px;
  cursor: nesw-resize;
}

.pdf-modal-resize-handle-sw {
  bottom: 6px;
  left: 6px;
  cursor: nesw-resize;
}

.pdf-modal-resize-handle-se {
  bottom: 6px;
  right: 6px;
  cursor: nwse-resize;
}

.pdf-modal-close {
  position: absolute;
  top: 8px;
  right: 8px;
  background: transparent;
  border: none;
  font-size: 24px;
  line-height: 1;
  color: var(--ink);
  cursor: pointer;
  z-index: 10;
}

.quiz-history-item.incorrect .result {
  color: var(--bad);
}

.quiz-history-item.skipped .result {
  color: var(--warn);
}

.quiz-footer {
  text-align: center;
}

/* 考试历史样式 */
.exam-history {
  margin-top: 20px;
}

.exam-history h3 {
  margin: 0 0 12px;
  color: var(--muted);
  font-size: 16px;
  text-align: center;
}

.exam-history-list {
  max-height: 300px;
  overflow-y: auto;
  background: color-mix(in oklab, var(--card), black 8%);
  border-radius: 8px;
  border: 1px solid color-mix(in oklab, var(--card), white 5%);
}

.no-history {
  padding: 20px;
  text-align: center;
  color: var(--muted);
  font-style: italic;
}

.exam-history-item {
  display: grid;
  grid-template-columns: 60px 1fr 100px 80px 120px;
  gap: 12px;
  align-items: center;
  padding: 12px 16px;
  border-bottom: 1px dashed #2b3a6b;
  font-size: 14px;
}

.exam-history-item:last-child {
  border-bottom: none;
}

.exam-history-item .page {
  font-weight: 600;
  color: var(--accent);
  text-align: center;
}

.exam-history-item .type {
  color: var(--ink);
  font-weight: 500;
}

.exam-history-item .result {
  text-align: center;
  font-weight: 600;
}

.exam-history-item .accuracy {
  text-align: center;
  font-weight: 500;
}

.page-title {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}

.link-button {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  text-decoration: none;
  border: 1px solid #2b3a6b;
  background: linear-gradient(180deg, #1a2450, #121a33);
  color: var(--ink);
  padding: 10px 14px;
  border-radius: 10px;
}

.prompt-box {
  margin-top: 12px;
  padding: 12px;
  background: #0f1630;
  border: 1px solid #2b3a6b;
  border-radius: 10px;
  color: var(--ink);
  font-size: 12px;
  line-height: 1.5;
  white-space: pre-wrap;
}

.page-meta {
  margin-bottom: 12px;
}

.page-meta-card {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 12px;
  background: color-mix(in oklab, var(--card), black 8%);
  border-radius: 12px;
  border: 1px solid color-mix(in oklab, var(--card), white 5%);
}

.meta-title {
  font-weight: 600;
  font-size: 18px;
}

.meta-sub {
  color: var(--muted);
  font-size: 13px;
  margin-top: 4px;
}

.grammar-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.grammar-card {
  padding: 14px;
  border-radius: 12px;
  background: color-mix(in oklab, var(--card), black 6%);
  border: 1px solid color-mix(in oklab, var(--card), white 6%);
}

.grammar-header {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  margin-bottom: 10px;
}

.grammar-index {
  min-width: 38px;
  height: 38px;
  border-radius: 12px;
  background: #162047;
  border: 1px solid #2b3a6b;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  color: var(--accent);
}

.grammar-title {
  font-size: 16px;
  font-weight: 600;
}

.grammar-expl {
  color: var(--muted);
  margin-top: 6px;
  line-height: 1.5;
}

.grammar-block h4 {
  margin: 10px 0 6px;
  color: var(--muted);
  font-size: 14px;
}

.example-list,
.note-list,
.extra-list {
  margin: 0;
  padding-left: 20px;
}

.example-list li,
.note-list li,
.extra-list li {
  margin-bottom: 8px;
}

.example-jp {
  font-size: 15px;
  line-height: 1.5;
}

.example-cn {
  color: var(--muted);
  font-size: 13px;
  margin-top: 4px;
}

.example-source {
  color: var(--muted);
  font-size: 12px;
  margin-top: 2px;
}

.underline {
  border-bottom: 2px solid var(--accent);
  padding-bottom: 1px;
}

.exam-panel {
  margin-top: 12px;
  padding: 14px;
  border-radius: 12px;
  background: color-mix(in oklab, var(--card), black 8%);
  border: 1px solid color-mix(in oklab, var(--card), white 5%);
}

.exam-header {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  color: var(--muted);
  font-size: 13px;
  margin-bottom: 10px;
}

.exam-question {
  font-size: 18px;
  line-height: 1.6;
  margin-bottom: 12px;
}

.exam-sentence {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  align-items: center;
}

.exam-blank {
  min-width: 120px;
  padding: 6px 10px;
  border-radius: 8px;
  border: 1px solid #2b3a6b;
  background: #0f1630;
  color: var(--ink);
  font-size: 15px;
}

.exam-hint {
  margin-top: 8px;
  color: var(--muted);
  font-size: 13px;
}

.exam-history-item .time {
  text-align: center;
  color: var(--muted);
  font-size: 12px;
}

.exam-history-item .count {
  position: absolute;
  top: 4px;
  right: 8px;
  background: var(--accent);
  color: white;
  border-radius: 10px;
  padding: 2px 6px;
  font-size: 10px;
  font-weight: 600;
}

.exam-history-item {
  position: relative;
}

/* 考试类型颜色标识 */
.exam-history-item.type-seq .type::before {
  content: "📝 ";
}

.exam-history-item.type-shuffle .type::before {
  content: "🔀 ";
}

.exam-history-item.type-reading .type::before {
  content: "📖 ";
}

.exam-history-item.type-fuzzy .type::before {
  content: "🎯 ";
}

/* 正确率颜色 */
.exam-history-item .accuracy.high {
  color: var(--good);
}

.exam-history-item .accuracy.medium {
  color: var(--warn);
}

.exam-history-item .accuracy.low {
  color: var(--bad);
}

/* 响应式调整 */
@media (max-width: 768px) {
  .exam-history-item {
    grid-template-columns: 50px 1fr 80px 60px 100px;
    gap: 8px;
    padding: 10px 12px;
    font-size: 13px;
  }
  
  .exam-history-item .time {
    font-size: 11px;
  }
}

/* 选项卡样式 */
.tab-container {
  margin-top: 16px;
}

.tab-buttons {
  display: flex;
  gap: 8px;
  margin-bottom: 16px;
  border-bottom: 1px solid #2b3a6b;
  padding-bottom: 8px;
}

.tab-btn {
  background: transparent;
  border: none;
  color: var(--muted);
  padding: 8px 16px;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.2s ease;
}

.tab-btn:hover {
  background: color-mix(in oklab, var(--card), white 5%);
  color: var(--ink);
}

.tab-btn.active {
  background: var(--accent);
  color: white;
}

.tab-panel {
  display: none;
}

.tab-panel.active {
  display: block;
}