/* ============ Reset & Base ============ */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

.hidden {
  display: none !important;
}

:root {
  --primary: #4f46e5;
  --primary-light: #818cf8;
  --primary-dark: #3730a3;
  --primary-bg: #eef2ff;
  --success: #16a34a;
  --success-bg: #f0fdf4;
  --danger: #dc2626;
  --danger-bg: #fef2f2;
  --warning: #d97706;
  --warning-bg: #fffbeb;
  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-300: #d1d5db;
  --gray-400: #9ca3af;
  --gray-500: #6b7280;
  --gray-600: #4b5563;
  --gray-700: #374151;
  --gray-800: #1f2937;
  --gray-900: #111827;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 1px 3px rgba(0,0,0,0.08), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -2px rgba(0,0,0,0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.1), 0 4px 6px -4px rgba(0,0,0,0.05);
  --transition: all 0.2s ease;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans SC", sans-serif;
  background: var(--gray-50);
  color: var(--gray-800);
  line-height: 1.6;
  min-height: 100vh;
}

/* ============ Navbar ============ */
.navbar {
  background: white;
  border-bottom: 1px solid var(--gray-200);
  padding: 0 24px;
  height: 60px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow);
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 18px;
  font-weight: 700;
  color: var(--primary);
}

.logo {
  font-size: 24px;
}

.nav-tabs {
  display: flex;
  gap: 4px;
}

.nav-tab {
  padding: 8px 16px;
  border: none;
  background: transparent;
  color: var(--gray-500);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  border-radius: var(--radius-sm);
  transition: var(--transition);
}

.nav-tab:hover {
  background: var(--gray-100);
  color: var(--gray-700);
}

.nav-tab.active {
  background: var(--primary-bg);
  color: var(--primary);
}

.btn-logout {
  margin-left: 12px;
  padding: 6px 14px;
  border: 1px solid var(--gray-400);
  border-radius: 8px;
  background: transparent;
  color: var(--gray-400);
  font-size: 13px;
  cursor: pointer;
  white-space: nowrap;
}
.btn-logout:hover {
  border-color: var(--danger);
  color: var(--danger);
}

/* ============ Content & Views ============ */
.content {
  max-width: 960px;
  margin: 0 auto;
  padding: 32px 24px;
}

.view {
  display: none;
  animation: fadeIn 0.3s ease;
}

.view.active {
  display: block;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ============ Dashboard ============ */
.stats-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  margin-bottom: 32px;
}

.stat-card {
  background: white;
  border-radius: var(--radius);
  padding: 20px;
  text-align: center;
  box-shadow: var(--shadow);
  border: 1px solid var(--gray-200);
}

.stat-card.highlight {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
  color: white;
  border: none;
}

.stat-value {
  font-size: 32px;
  font-weight: 700;
  margin-bottom: 4px;
}

.stat-label {
  font-size: 13px;
  color: var(--gray-500);
}

.stat-card.highlight .stat-label {
  color: rgba(255,255,255,0.85);
}

/* ============ Study Panel ============ */
.study-panel {
  background: white;
  border-radius: var(--radius);
  padding: 32px;
  box-shadow: var(--shadow);
  border: 1px solid var(--gray-200);
  margin-bottom: 24px;
}

.study-panel h2 {
  font-size: 22px;
  margin-bottom: 20px;
}

.study-overview {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.overview-info {
  flex: 1;
}

.overview-text {
  font-size: 16px;
  color: var(--gray-600);
}

.overview-text strong {
  color: var(--primary);
  font-size: 20px;
}

/* ============ Buttons ============ */
.btn {
  padding: 10px 20px;
  border: none;
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn-primary {
  background: var(--primary);
  color: white;
}

.btn-primary:hover:not(:disabled) {
  background: var(--primary-dark);
}

.btn-secondary {
  background: var(--gray-100);
  color: var(--gray-700);
}

.btn-secondary:hover {
  background: var(--gray-200);
}

.btn-large {
  padding: 10px 28px;
  font-size: 15px;
}

.btn-danger {
  background: var(--danger-bg);
  color: var(--danger);
}

.btn-danger:hover {
  background: #fee2e2;
}

.btn-link {
  background: none;
  border: none;
  color: var(--gray-400);
  font-size: 13px;
  cursor: pointer;
  padding: 4px 8px;
  margin-top: 6px;
  text-decoration: underline;
}
.btn-link:hover {
  color: var(--danger);
}

/* ============ Recent Words ============ */
.recent-words h3 {
  font-size: 16px;
  margin-bottom: 12px;
  color: var(--gray-700);
}

.word-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.word-chip {
  background: white;
  border: 1px solid var(--gray-200);
  border-radius: 20px;
  padding: 6px 14px;
  font-size: 13px;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: 6px;
}

.word-chip:hover {
  border-color: var(--primary-light);
  background: var(--primary-bg);
}

.word-chip .chip-status {
  width: 8px;
  height: 8px;
  border-radius: 50%;
}

.status-new { background: var(--gray-400); }
.status-learning { background: var(--warning); }
.status-review { background: var(--primary-light); }
.status-mastered { background: var(--success); }

/* ============ Add Word ============ */
.add-word-panel {
  background: white;
  border-radius: var(--radius);
  padding: 32px;
  box-shadow: var(--shadow);
  border: 1px solid var(--gray-200);
}

.add-word-panel h2 {
  margin-bottom: 20px;
}

.input-group {
  display: flex;
  gap: 12px;
}

.input-group input {
  flex: 1;
  padding: 12px 16px;
  border: 2px solid var(--gray-200);
  border-radius: var(--radius-sm);
  font-size: 16px;
  transition: var(--transition);
}

.input-group input:focus {
  outline: none;
  border-color: var(--primary);
}

.hint {
  margin-top: 8px;
  font-size: 13px;
  color: var(--gray-400);
}

/* Generation Status */
.gen-status {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 24px;
  margin-top: 20px;
  background: var(--primary-bg);
  border-radius: var(--radius-sm);
}

.spinner {
  width: 24px;
  height: 24px;
  border: 3px solid var(--primary-light);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* Word Preview */
.word-preview {
  margin-top: 24px;
  background: var(--gray-50);
  border-radius: var(--radius);
  padding: 24px;
  border: 1px solid var(--gray-200);
}

.preview-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
}

.preview-word {
  font-size: 28px;
  font-weight: 700;
}

.preview-phonetic {
  color: var(--gray-500);
  font-size: 16px;
}

.preview-meaning {
  font-size: 16px;
  color: var(--primary);
  font-weight: 600;
  margin-bottom: 16px;
}

/* 中文释义 + 词性标签 */
.meaning-item {
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
  line-height: 1.7;
}
/* 详情/预览/弹窗里每条释义独占一行 */
.preview-meaning .meaning-item,
.modal-meaning .meaning-item,
.result-meaning .meaning-item {
  display: flex;
}
.pos-badge {
  display: inline-block;
  flex: 0 0 auto;
  font-size: 11px;
  font-weight: 700;
  line-height: 1.5;
  padding: 1px 7px;
  border-radius: 999px;
  color: #fff;
  background: var(--gray-400);
  white-space: nowrap;
  transform: translateY(-1px);
}
/* 词性配色 */
.pos-verb  { background: #2f80ed; } /* 动词 */
.pos-noun  { background: #27ae60; } /* 名词 */
.pos-adj   { background: #eb9b16; } /* 形容词 */
.pos-adv   { background: #9b51e0; } /* 副词 */
.pos-prep  { background: #00a3a3; } /* 介词 */
.pos-conj  { background: #d35400; } /* 连词 */
.pos-pron  { background: #c2185b; } /* 代词 */
.pos-int   { background: #8e44ad; } /* 感叹词 */
.pos-num   { background: #607d8b; } /* 数词 */
.pos-art   { background: #795548; } /* 冠词 */
.pos-other { background: var(--gray-400); }

.preview-section {
  margin-bottom: 16px;
}

.preview-section h4 {
  font-size: 13px;
  color: var(--gray-500);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 8px;
}

.preview-section .item {
  background: white;
  padding: 10px 14px;
  border-radius: var(--radius-sm);
  margin-bottom: 6px;
  font-size: 14px;
  border: 1px solid var(--gray-200);
}

.preview-section .item .item-meaning {
  color: var(--gray-500);
  font-size: 13px;
}

.preview-example {
  background: white;
  padding: 14px;
  border-radius: var(--radius-sm);
  border-left: 3px solid var(--primary);
  font-size: 15px;
  line-height: 1.8;
}

.preview-example .translation {
  color: var(--gray-500);
  font-size: 14px;
  margin-top: 4px;
}

.preview-example .highlight-word {
  background: var(--warning-bg);
  color: var(--warning);
  padding: 1px 6px;
  border-radius: 4px;
  font-weight: 600;
}

.preview-actions {
  margin-top: 20px;
  display: flex;
  gap: 12px;
}

/* Batch preview cards */
.preview-card {
  background: white;
  border-radius: var(--radius-sm);
  padding: 20px;
  margin-bottom: 16px;
  border: 1px solid var(--gray-200);
}

.preview-card.error-card {
  border-color: var(--danger);
  background: var(--danger-bg);
}

.preview-card.reset-card {
  border-color: var(--warning);
  background: var(--warning-bg);
}

.batch-summary {
  display: flex;
  gap: 16px;
  padding: 12px 16px;
  background: var(--gray-100);
  border-radius: var(--radius-sm);
  margin-bottom: 16px;
  font-size: 14px;
  font-weight: 600;
}

.batch-ok { color: var(--success); }
.batch-fail { color: var(--danger); }
.batch-reset { color: var(--warning); }

.hint code {
  background: var(--gray-100);
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 13px;
  color: var(--primary);
}

.badge-ai {
  background: var(--success-bg);
  color: var(--success);
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 11px;
  font-weight: 600;
}

.badge-manual {
  background: var(--warning-bg);
  color: var(--warning);
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 11px;
  font-weight: 600;
}

.badge-reset {
  background: var(--warning-bg);
  color: var(--warning);
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 11px;
  font-weight: 600;
}

/* ============ Word Bank ============ */
.bank-panel {
  background: white;
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow);
  border: 1px solid var(--gray-200);
}

.bank-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
}

.bank-header h2 {
  font-size: 20px;
}

.bank-controls {
  display: flex;
  gap: 12px;
}

.bank-action-bar {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 12px 0;
  margin-bottom: 8px;
  border-bottom: 1px solid var(--gray-100);
}

.select-all-label {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 14px;
  color: var(--gray-600);
  cursor: pointer;
  user-select: none;
}

.select-all-label input[type="checkbox"] {
  width: 16px;
  height: 16px;
  cursor: pointer;
  accent-color: var(--primary);
}

.select-count {
  font-size: 13px;
  color: var(--gray-500);
}

.btn-export {
  margin-left: auto;
  font-size: 13px;
  padding: 8px 16px;
}

.search-input, .filter-select {
  padding: 8px 14px;
  border: 1px solid var(--gray-300);
  border-radius: var(--radius-sm);
  font-size: 14px;
}

.search-input:focus, .filter-select:focus {
  outline: none;
  border-color: var(--primary);
}

.word-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.word-row {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 14px 16px;
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: var(--transition);
  flex-wrap: wrap;
}

.word-row:hover {
  background: var(--gray-50);
  border-color: var(--primary-light);
}

.word-row .word-checkbox {
  width: 16px;
  height: 16px;
  cursor: pointer;
  accent-color: var(--primary);
  flex-shrink: 0;
}

.word-row .word-text {
  font-size: 16px;
  font-weight: 600;
  min-width: 120px;
}

.word-row .word-phonetic {
  font-size: 13px;
  color: var(--gray-400);
  min-width: 100px;
}

.word-row .word-meaning {
  flex: 1;
  font-size: 14px;
  color: var(--gray-600);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.word-row .word-status {
  font-size: 12px;
  padding: 3px 10px;
  border-radius: 12px;
  font-weight: 500;
}

.word-row .word-delete {
  opacity: 0;
  background: none;
  border: none;
  color: var(--danger);
  cursor: pointer;
  font-size: 18px;
  padding: 4px;
  transition: var(--transition);
}

.word-row:hover .word-delete {
  opacity: 0.6;
}

.word-row .word-delete:hover {
  opacity: 1;
}

.word-row .word-example {
  flex-basis: 100%;
  font-size: 13px;
  color: var(--gray-500);
  line-height: 1.5;
  padding-top: 6px;
  border-top: 1px dashed var(--gray-100);
  margin-top: 2px;
}

.word-row .word-example-cn {
  display: block;
  font-size: 12px;
  color: var(--gray-400);
  margin-top: 2px;
}

.btn-regen {
  font-size: 13px;
  padding: 6px 14px;
}

.btn-regen:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.empty-state {
  text-align: center;
  padding: 48px 24px;
  color: var(--gray-400);
  font-size: 15px;
}

/* ============ Stats ============ */
.stats-panel {
  background: white;
  border-radius: var(--radius);
  padding: 32px;
  box-shadow: var(--shadow);
  border: 1px solid var(--gray-200);
}

.stats-panel h2 {
  margin-bottom: 24px;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-bottom: 32px;
}

.stat-card-large {
  background: var(--gray-50);
  border-radius: var(--radius);
  padding: 24px;
  text-align: center;
  border: 1px solid var(--gray-200);
}

.stat-card-large.highlight {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
  color: white;
  border: none;
}

.stat-value-large {
  font-size: 40px;
  font-weight: 700;
}

.stat-label-large {
  font-size: 14px;
  color: var(--gray-500);
  margin-top: 4px;
}

.stat-card-large.highlight .stat-label-large {
  color: rgba(255,255,255,0.85);
}

.status-distribution h3 {
  font-size: 16px;
  margin-bottom: 16px;
}

.progress-bars {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.progress-bar-item {
  display: flex;
  align-items: center;
  gap: 12px;
}

.progress-bar-item .label {
  width: 80px;
  font-size: 14px;
  color: var(--gray-600);
}

.progress-bar-item .bar-container {
  flex: 1;
  height: 24px;
  background: var(--gray-100);
  border-radius: 12px;
  overflow: hidden;
}

.progress-bar-item .bar {
  height: 100%;
  border-radius: 12px;
  transition: width 0.5s ease;
}

.progress-bar-item .count {
  width: 40px;
  text-align: right;
  font-size: 14px;
  font-weight: 600;
}

/* ============ Settings ============ */
.settings-panel {
  background: white;
  border-radius: var(--radius);
  padding: 32px;
  box-shadow: var(--shadow);
  border: 1px solid var(--gray-200);
  max-width: 640px;
}

.settings-panel h2 {
  margin-bottom: 24px;
}

.settings-section {
  margin-bottom: 32px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--gray-100);
}

.settings-section:last-of-type {
  border-bottom: none;
}

.settings-section h3 {
  font-size: 16px;
  margin-bottom: 12px;
}

.setting-desc {
  font-size: 13px;
  color: var(--gray-400);
  margin-bottom: 16px;
}

.setting-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
}

.setting-item label {
  font-size: 14px;
  color: var(--gray-600);
}

.setting-input {
  padding: 8px 12px;
  border: 1px solid var(--gray-300);
  border-radius: var(--radius-sm);
  font-size: 14px;
  width: 240px;
}

.setting-input:focus {
  outline: none;
  border-color: var(--primary);
}

.setting-actions {
  display: flex;
  gap: 12px;
}

.setting-status {
  margin-top: 8px;
  font-size: 13px;
}

.setting-status.ok { color: var(--success); }
.setting-status.error { color: var(--danger); }

/* Model profile manager */
.profiles-block { margin-top: 18px; border-top: 1px dashed var(--gray-200); padding-top: 14px; }
.profiles-list { margin-top: 10px; display: flex; flex-direction: column; gap: 8px; }
.profile-empty { font-size: 12px; color: var(--gray-400); padding: 8px 0; }
.profile-row {
  display: flex; align-items: center; justify-content: space-between;
  gap: 10px; padding: 8px 10px; border: 1px solid var(--gray-200);
  border-radius: 8px; background: #fff;
}
.profile-row.active { border-color: var(--primary); background: #f0f7ff; }
.profile-meta { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.profile-name { font-weight: 600; color: var(--gray-800); }
.profile-model { font-size: 12px; color: var(--gray-500); }
.profile-badge {
  font-size: 11px; color: #fff; background: var(--primary);
  padding: 1px 8px; border-radius: 999px;
}
.profile-actions { display: flex; gap: 6px; }
.btn-tiny { padding: 4px 10px; font-size: 12px; border-radius: 6px; }
.setting-inline { display: flex; gap: 8px; align-items: center; }
.setting-inline .setting-input { flex: 1; }

.setting-hint {
  font-size: 12px;
  color: var(--gray-400);
  line-height: 1.5;
  margin: 0;
  padding: 6px 10px;
  background: var(--gray-50);
  border-radius: var(--radius-sm);
  border-left: 3px solid var(--primary-light);
}

#model-hint-row {
  justify-content: flex-start;
}

/* ============ Study Overlay ============ */
.study-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: white;
  z-index: 1000;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  animation: fadeIn 0.3s ease;
  overflow-y: auto;
}

.study-overlay.hidden {
  display: none;
}

.study-container {
  width: 100%;
  max-width: 640px;
  padding: 24px;
  height: 100%;
  display: flex;
  flex-direction: column;
  overflow-y: auto;
}

.study-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 20px;
}

.study-nav {
  display: flex;
  gap: 6px;
}

.btn-nav {
  padding: 4px 10px;
  font-size: 12px;
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-sm);
  background: white;
  color: var(--gray-600);
  cursor: pointer;
  transition: var(--transition);
  white-space: nowrap;
}

.btn-nav:hover:not(:disabled) {
  border-color: var(--primary-light);
  background: var(--primary-bg);
  color: var(--primary);
}

.btn-nav:disabled {
  opacity: 0.35;
  cursor: not-allowed;
}

.study-progress {
  font-size: 14px;
  color: var(--gray-500);
  white-space: nowrap;
}

.progress-bar-container {
  flex: 1;
  height: 6px;
  background: var(--gray-100);
  border-radius: 3px;
  overflow: hidden;
}

.progress-bar {
  height: 100%;
  background: var(--primary);
  border-radius: 3px;
  transition: width 0.3s ease;
  width: 0%;
}

.btn-close {
  background: none;
  border: none;
  font-size: 20px;
  cursor: pointer;
  color: var(--gray-400);
  padding: 4px 8px;
  border-radius: var(--radius-sm);
  transition: var(--transition);
}

.btn-close:hover {
  background: var(--gray-100);
  color: var(--gray-700);
}

/* Study Card */
.study-card {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: min-content;
  padding-bottom: 20px;
}

.study-phase {
  width: 100%;
  text-align: center;
}

.study-phase.hidden {
  display: none;
}

.word-display {
  margin-bottom: 20px;
}

.study-word {
  font-size: 40px;
  font-weight: 700;
  color: var(--gray-900);
  margin-bottom: 4px;
}

.study-phonetic {
  font-size: 16px;
  color: var(--gray-400);
}

.btn-pronounce {
  background: var(--primary-bg);
  border: none;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  font-size: 20px;
  cursor: pointer;
  transition: var(--transition);
  margin-top: 12px;
}

.btn-pronounce:hover {
  background: var(--primary-light);
  transform: scale(1.1);
}

.btn-pronounce-sm {
  width: 34px;
  height: 34px;
  font-size: 15px;
  margin-top: 0;
  flex-shrink: 0;
}

.word-with-speaker {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
}

.example-with-speaker {
  display: flex;
  align-items: flex-start;
  gap: 8px;
}

.example-with-speaker .example-sentence {
  flex: 1;
}

/* Dual 英/美 speaker pair on the study result (example) page */
.speaker-pair {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  flex-shrink: 0;
}

.speaker-pair .btn-accent {
  border: 1px solid var(--border, #d1d5db);
  background: var(--card, #fff);
  color: var(--text, #1f2937);
  border-radius: 999px;
  padding: 4px 10px;
  font-size: 13px;
  line-height: 1;
  cursor: pointer;
  transition: var(--transition, all 0.15s ease);
  white-space: nowrap;
}

.speaker-pair .btn-accent:hover {
  transform: translateY(-1px);
  border-color: var(--primary, #6366f1);
}

.speaker-pair .btn-accent.is-active {
  background: var(--primary, #6366f1);
  border-color: var(--primary, #6366f1);
  color: #fff;
  font-weight: 600;
}

.word-with-speaker .speaker-pair {
  margin-top: 12px;
}

.phase-hint {
  font-size: 14px;
  color: var(--gray-400);
  margin-bottom: 16px;
}

/* Options Grid */
.options-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  max-width: 500px;
  margin: 0 auto;
}

.option-btn {
  padding: 12px 20px;
  border: 2px solid var(--gray-200);
  border-radius: var(--radius);
  font-size: 15px;
  cursor: pointer;
  transition: var(--transition);
  background: white;
  text-align: center;
}

.option-btn:hover {
  border-color: var(--primary-light);
  background: var(--primary-bg);
}

.option-btn.correct {
  border-color: var(--success);
  background: var(--success-bg);
  color: var(--success);
}

.option-btn.wrong {
  border-color: var(--danger);
  background: var(--danger-bg);
  color: var(--danger);
}

.option-btn.disabled {
  pointer-events: none;
  opacity: 0.5;
}

/* Result Phase */
.result-nav {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  width: 100%;
  margin-bottom: 12px;
}

.btn-nav-arrow {
  padding: 6px 16px;
  font-size: 14px;
  font-weight: 600;
  border: 1px solid var(--gray-200);
  border-radius: var(--radius);
  background: white;
  color: var(--gray-600);
  cursor: pointer;
  transition: var(--transition);
  white-space: nowrap;
}

.btn-nav-arrow:hover:not(:disabled) {
  border-color: var(--primary);
  background: var(--primary);
  color: white;
}

.btn-nav-arrow:disabled {
  opacity: 0.3;
  cursor: not-allowed;
}

.result-badge {
  display: inline-block;
  padding: 4px 16px;
  border-radius: 20px;
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 0;
}

.result-badge.correct {
  background: var(--success-bg);
  color: var(--success);
}

.result-badge.wrong {
  background: var(--danger-bg);
  color: var(--danger);
}

.result-meaning {
  font-size: 16px;
  color: var(--primary);
  font-weight: 600;
  margin-top: 4px;
}

.example-section {
  background: var(--gray-50);
  border-radius: var(--radius);
  padding: 14px 16px;
  margin: 12px 0;
  text-align: left;
  width: 100%;
  max-width: 500px;
}

.example-label-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 8px;
}

.example-label {
  font-size: 12px;
  color: var(--gray-400);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.btn-regenerate {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 3px 10px;
  font-size: 12px;
  border: 1px solid var(--gray-300);
  border-radius: 6px;
  background: var(--gray-100);
  color: var(--gray-600);
  cursor: pointer;
  transition: all 0.2s;
  white-space: nowrap;
}

.btn-regenerate:hover {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

.btn-regenerate:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn-regenerate.loading {
  animation: spin 1s linear infinite;
}

@keyframes spin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

.example-sentence {
  font-size: 15px;
  line-height: 1.6;
  color: var(--gray-800);
}

.example-sentence .highlight-word {
  background: var(--warning-bg);
  color: var(--warning);
  padding: 1px 6px;
  border-radius: 4px;
  font-weight: 600;
  cursor: pointer;
  text-decoration: underline;
  text-decoration-style: dotted;
  text-underline-offset: 3px;
  transition: all 0.2s;
}

.example-sentence .highlight-word:hover {
  background: var(--warning);
  color: #fff;
}

.example-translation-wrapper {
  margin-top: 6px;
  display: flex;
  align-items: flex-start;
  gap: 8px;
  flex-wrap: wrap;
}

.btn-mastered {
  position: absolute;
  right: 0;
  top: 50%;
  transform: translateY(-50%);
  background: var(--success-bg, #ecfdf5);
  color: var(--success, #16a34a);
  border: 1.5px solid var(--success, #16a34a);
  border-radius: 999px;
  padding: 5px 14px;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  box-shadow: 0 1px 3px rgba(22, 163, 74, 0.15);
  white-space: nowrap;
}

.btn-mastered:hover:not(:disabled) {
  background: var(--success, #16a34a);
  color: #fff;
  box-shadow: 0 4px 12px rgba(22, 163, 74, 0.3);
}

.btn-mastered:disabled {
  cursor: default;
  opacity: 0.85;
}

.btn-mastered.is-done {
  background: var(--success, #16a34a);
  color: #fff;
  border-color: var(--success, #16a34a);
}

.btn-translation-toggle {
  display: inline-flex;
  align-items: center;
  padding: 3px 12px;
  font-size: 13px;
  border: 1px solid var(--gray-300);
  border-radius: 6px;
  background: var(--gray-100);
  color: var(--gray-600);
  cursor: pointer;
  transition: all 0.2s;
  white-space: nowrap;
}

.btn-translation-toggle:hover {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

.example-translation {
  font-size: 14px;
  color: var(--gray-500);
  margin-top: 4px;
  width: 100%;
}

.related-words {
  margin-top: 12px;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.related-word-tag {
  background: var(--warning-bg);
  color: var(--warning);
  padding: 2px 10px;
  border-radius: 12px;
  font-size: 12px;
  font-weight: 500;
}

.word-details {
  width: 100%;
  max-width: 500px;
  margin-bottom: 16px;
}

.word-details .detail-section {
  text-align: left;
  margin-bottom: 10px;
}

.word-details .detail-label {
  font-size: 12px;
  color: var(--gray-400);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 4px;
}

.word-details .detail-item {
  font-size: 14px;
  color: var(--gray-600);
  padding: 3px 0;
}

/* Study Complete */
.study-complete {
  text-align: center;
}

.study-complete.hidden {
  display: none;
}

.complete-icon {
  font-size: 64px;
  margin-bottom: 16px;
}

.study-complete h2 {
  font-size: 28px;
  margin-bottom: 24px;
}

.complete-stats {
  display: flex;
  gap: 32px;
  justify-content: center;
  margin-bottom: 32px;
}

.complete-stat {
  text-align: center;
}

.complete-stat .num {
  font-size: 36px;
  font-weight: 700;
  color: var(--primary);
}

.complete-stat .label {
  font-size: 14px;
  color: var(--gray-500);
}

.complete-actions {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}

/* ============ Modal ============ */
.modal {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 999;
  display: flex;
  align-items: center;
  justify-content: center;
}

.modal.hidden {
  display: none;
}

.modal-overlay {
  position: absolute;
  width: 100%;
  height: 100%;
  background: rgba(0,0,0,0.4);
}

.modal-content {
  position: relative;
  z-index: 1; /* keep content above the dim .modal-overlay backdrop */
  background: white;
  border-radius: var(--radius);
  padding: 32px;
  max-width: 600px;
  width: 90%;
  max-height: 80vh;
  overflow-y: auto;
  box-shadow: var(--shadow-lg);
}

.modal-close {
  position: absolute;
  top: 16px;
  right: 16px;
  background: none;
  border: none;
  font-size: 20px;
  cursor: pointer;
  color: var(--gray-400);
}

/* Confirm Modal */
#confirm-modal {
  z-index: 1100;
}
.confirm-content {
  max-width: 360px;
  text-align: center;
  padding: 28px 24px 20px;
}
.confirm-content h3 {
  margin: 0 0 12px;
  font-size: 18px;
  color: var(--gray-800);
}
.confirm-content p {
  margin: 0 0 20px;
  font-size: 14px;
  line-height: 1.6;
  color: var(--gray-600);
}
.confirm-actions {
  display: flex;
  gap: 12px;
  justify-content: center;
}
.confirm-actions .btn {
  min-width: 96px;
}

.modal-word {
  font-size: 28px;
  font-weight: 700;
  margin-bottom: 4px;
}

.modal-phonetic {
  color: var(--gray-400);
  margin-bottom: 16px;
}

.modal-meaning {
  font-size: 16px;
  color: var(--primary);
  font-weight: 600;
  margin-bottom: 20px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--gray-100);
}

.modal-section {
  margin-bottom: 20px;
}

.modal-section h4 {
  font-size: 13px;
  color: var(--gray-500);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 8px;
}

.modal-section .item {
  background: var(--gray-50);
  padding: 10px 14px;
  border-radius: var(--radius-sm);
  margin-bottom: 6px;
  font-size: 14px;
}

/* ============ Toast ============ */
.toast {
  position: fixed;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--gray-900);
  color: white;
  padding: 12px 24px;
  border-radius: var(--radius-sm);
  font-size: 14px;
  z-index: 2000;
  box-shadow: var(--shadow-lg);
  animation: toastIn 0.3s ease;
}

.toast.hidden {
  display: none;
}

.toast.error {
  background: var(--danger);
}

.toast.success {
  background: var(--success);
}

@keyframes toastIn {
  from { transform: translate(-50%, 20px); opacity: 0; }
  to { transform: translate(-50%, 0); opacity: 1; }
}

/* ============ Responsive ============ */
@media (max-width: 768px) {
  .navbar {
    padding: 0 12px;
  }

  .nav-tabs {
    gap: 0;
  }

  .nav-tab {
    padding: 8px 10px;
    font-size: 13px;
  }

  .content {
    padding: 16px 12px;
  }

  .stats-row {
    grid-template-columns: repeat(2, 1fr);
  }

  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .study-overview {
    flex-direction: column;
    text-align: center;
  }

  .bank-header {
    flex-direction: column;
    align-items: stretch;
    gap: 12px;
  }

  .bank-controls {
    flex-direction: column;
  }

  .bank-action-bar {
    flex-wrap: wrap;
  }

  .options-grid {
    grid-template-columns: 1fr;
  }

  .study-word {
    font-size: 30px;
  }

  .input-group {
    flex-direction: column;
  }

  .word-row {
    flex-wrap: wrap;
  }

  .word-row .word-text {
    min-width: auto;
  }

  .word-row .word-phonetic {
    min-width: auto;
  }
}

/* ============ Lookup Autocomplete & Spell-check ============ */
.lookup-input-group {
  position: relative;
}

.suggestions {
  position: absolute;
  top: calc(100% + 6px);
  left: 0;
  right: 0;
  background: #fff;
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-sm);
  box-shadow: 0 10px 28px rgba(15, 23, 42, 0.16);
  max-height: 264px;
  overflow-y: auto;
  z-index: 60;
  padding: 4px;
}

.suggestion-item {
  padding: 9px 12px;
  cursor: pointer;
  font-size: 15px;
  color: var(--gray-800);
  border-radius: 8px;
  line-height: 1.3;
}

.suggestion-item:hover,
.suggestion-item.active {
  background: var(--primary-bg);
  color: var(--primary-dark);
}

.suggestion-item mark {
  background: transparent;
  color: var(--primary);
  font-weight: 700;
}

.lookup-hint {
  margin-top: 10px;
  font-size: 14px;
  color: #92400e;
  background: #fffbeb;
  border: 1px solid #fde68a;
  border-radius: var(--radius-sm);
  padding: 9px 12px;
}

.lookup-warn {
  margin-bottom: 14px;
  font-size: 14px;
  color: #b91c1c;
  background: #fef2f2;
  border: 1px solid #fecaca;
  border-radius: var(--radius-sm);
  padding: 11px 14px;
  line-height: 1.5;
}

.lookup-hint b,
.lookup-warn b {
  color: var(--primary);
  cursor: pointer;
  text-decoration: underline;
  text-underline-offset: 2px;
}

.lookup-hint b:hover,
.lookup-warn b:hover {
  color: var(--primary-dark);
}

/* ============ Admin summary cards ============ */
.admin-summary {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
  margin-bottom: 22px;
}
.summary-card {
  background: linear-gradient(135deg, #eef4ff, #f7faff);
  border: 1px solid var(--border, #e3e8f0);
  border-radius: 12px;
  padding: 16px 14px;
  text-align: center;
}
.summary-value {
  font-size: 26px;
  font-weight: 700;
  color: var(--primary, #2563eb);
  line-height: 1.1;
}
.summary-label {
  margin-top: 6px;
  font-size: 13px;
  color: #64748b;
}

/* ============ User stats modal ============ */
/* NOTE: must NOT reuse the generic `.modal-overlay` class — that one is also
   the dim backdrop inside #word-modal / #confirm-modal, and a later same-
   specificity rule here would override it, pushing the backdrop (z-index:1000)
   ABOVE the modal content (z-index:auto) and making confirm/cancel unclickable. */
.stats-modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.55);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1200;
  padding: 20px;
}
.stats-modal-overlay.hidden { display: none; }
.modal-box {
  background: #fff;
  width: min(760px, 96vw);
  max-height: 90vh;
  overflow-y: auto;
  border-radius: 16px;
  box-shadow: 0 24px 60px rgba(15, 23, 42, 0.3);
}
.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 22px;
  border-bottom: 1px solid var(--border, #e3e8f0);
  position: sticky;
  top: 0;
  background: #fff;
  z-index: 2;
}
.modal-header h3 { margin: 0; }
.modal-close {
  border: none;
  background: transparent;
  font-size: 28px;
  line-height: 1;
  color: #94a3b8;
  cursor: pointer;
}
.modal-close:hover { color: #475569; }
.modal-body { padding: 18px 22px 26px; }
.usm-totals {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin-bottom: 18px;
}
.usm-totals .t {
  background: #f1f5f9;
  border-radius: 10px;
  padding: 12px;
  text-align: center;
}
.usm-totals .t b { display: block; font-size: 22px; color: var(--primary, #2563eb); }
.usm-totals .t span { font-size: 12px; color: #64748b; }
.usm-chart-block { margin-top: 18px; }
.usm-chart-block h4 {
  margin: 0 0 8px;
  font-size: 14px;
  color: #334155;
}
.usm-chart {
  width: 100%;
  overflow-x: auto;
  background: #fafbfc;
  border: 1px solid var(--border, #e3e8f0);
  border-radius: 10px;
  padding: 10px;
}
.usm-chart svg { display: block; }
.usm-chart .axis-label { font-size: 10px; fill: #94a3b8; }
.usm-chart .bar-val { font-size: 10px; fill: #475569; font-weight: 600; }
.usm-chart .line-label { font-size: 11px; fill: var(--primary, #2563eb); font-weight: 600; }

/* ============ Admin: system log viewer ============ */
.log-filters {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
  margin: 14px 0 10px;
}
.log-input {
  width: auto !important;
  min-width: 120px;
  padding: 8px 10px !important;
  font-size: 13px;
}
#log-user, #log-q { min-width: 140px; }
.log-auto {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  color: #475569;
  cursor: pointer;
  user-select: none;
}
.log-auto input { cursor: pointer; }
.log-summary {
  font-size: 13px;
  color: #475569;
  margin-bottom: 10px;
}
.log-summary b { color: #1e293b; }
.badge-err, .badge-warn {
  display: inline-block;
  padding: 1px 9px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 600;
  margin-left: 4px;
}
.badge-err { background: #fef2f2; color: #b91c1c; }
.badge-warn { background: #fffbeb; color: #b45309; }

.log-list {
  max-height: 62vh;
  overflow-y: auto;
  border: 1px solid var(--border, #e3e8f0);
  border-radius: 12px;
  background: #fff;
}
.log-row {
  border-bottom: 1px solid #f1f5f9;
  cursor: pointer;
}
.log-row:last-child { border-bottom: none; }
.log-row:hover { background: #f8fafc; }
.log-head {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 8px 12px;
  font-size: 13px;
  line-height: 1.5;
}
.log-time {
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  color: #94a3b8;
  white-space: nowrap;
  flex: 0 0 auto;
}
.log-level {
  flex: 0 0 auto;
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  padding: 1px 8px;
  border-radius: 6px;
  letter-spacing: .03em;
}
.log-level-error { background: #fef2f2; color: #dc2626; }
.log-level-warn { background: #fffbeb; color: #d97706; }
.log-level-info { background: #eff6ff; color: #2563eb; }
.log-cat {
  flex: 0 0 auto;
  color: #64748b;
  background: #f1f5f9;
  border-radius: 6px;
  padding: 1px 8px;
  font-size: 12px;
}
.log-msg {
  flex: 1 1 auto;
  color: #1e293b;
  word-break: break-word;
}
.log-meta {
  display: none;
  margin: 0;
  padding: 10px 14px 12px 86px;
  background: #0f172a;
  color: #e2e8f0;
  font-size: 12px;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  white-space: pre-wrap;
  word-break: break-word;
  border-radius: 0 0 8px 8px;
}

/* ============ Admin: per-user daily study detail ============ */
.addm-days { margin-bottom: 16px; }
.addm-detail { margin-top: 8px; border-top: 1px solid #e2e8f0; padding-top: 14px; }
.addm-detail h4 { margin: 0 0 12px; font-size: 15px; color: #1e293b; }
.addm-cols { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.addm-col { background: #f8fafc; border: 1px solid #e2e8f0; border-radius: 10px; padding: 12px 14px; }
.addm-col-title { font-size: 13px; font-weight: 700; color: #334155; margin-bottom: 8px; }
.addm-words { margin: 0; padding-left: 18px; max-height: 320px; overflow-y: auto; }
.addm-words li { font-size: 13px; line-height: 1.7; color: #1e293b; }
@media (max-width: 640px) {
  .addm-cols { grid-template-columns: 1fr; }
}

/* ============ Today study: 检验 ============ */
.btn-sm {
  padding: 5px 12px;
  font-size: 13px;
  border: 1px solid var(--gray-200, #e2e8f0);
  background: #fff;
  color: var(--gray-700, #334155);
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.15s ease;
}
.btn-sm:hover { background: var(--gray-100, #f1f5f9); }
.btn-sm.active-ok {
  background: #dcfce7;
  border-color: #16a34a;
  color: #15803d;
  font-weight: 600;
}
.btn-sm.active-no {
  background: #fee2e2;
  border-color: #dc2626;
  color: #b91c1c;
  font-weight: 600;
}
.muted { color: var(--gray-400, #94a3b8); }

.check-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 4px;
}
.check-hide-label {
  font-size: 13px;
  color: #475569;
  display: flex;
  align-items: center;
  gap: 6px;
  cursor: pointer;
  user-select: none;
}
.check-summary { font-size: 13px; color: #475569; }
.check-summary b { font-size: 14px; }
.check-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
  max-height: 60vh;
  overflow-y: auto;
  padding-right: 4px;
}
.check-card {
  background: #f8fafc;
  border: 1px solid #e2e8f0;
  border-radius: 12px;
  padding: 14px 16px;
}
.check-en {
  font-size: 16px;
  line-height: 1.6;
  font-weight: 600;
  color: #1e293b;
  margin-bottom: 4px;
}
.check-zh {
  font-size: 14px;
  color: #64748b;
  line-height: 1.5;
  margin-bottom: 10px;
}
.check-actions { display: flex; gap: 10px; }

/* ============ Inline quick-lookup popup (tap a word in an example) ============ */
.quick-lookup-overlay {
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.55);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1300; /* above study-overlay (z-index:1000) */
  padding: 16px;
}
.quick-lookup-overlay.hidden { display: none; }
.quick-lookup-box {
  background: var(--card, #fff);
  border-radius: 16px;
  width: 100%;
  max-width: 460px;
  max-height: 85vh;
  overflow-y: auto;
  padding: 18px 20px 22px;
  position: relative;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
}
.quick-lookup-box .modal-close {
  position: absolute;
  top: 8px;
  right: 10px;
  background: transparent;
  border: none;
  font-size: 20px;
  line-height: 1;
  color: #94a3b8;
  cursor: pointer;
  padding: 4px 8px;
}
.quick-lookup-box .modal-close:hover { color: #475569; }
.ql-loading, .ql-error { padding: 22px 6px; font-size: 14px; color: var(--gray-500, #64748b); }
.ql-error { color: var(--danger, #e53e3e); }
.ql-card { text-align: center; padding: 10px 0; }
.ql-word { font-size: 22px; font-weight: 700; color: #1e293b; margin-bottom: 6px; }
.ql-note { color: #16a34a; font-size: 14px; margin-bottom: 16px; }
.ql-actions { display: flex; gap: 10px; justify-content: center; flex-wrap: wrap; }

/* Tappable words inside example sentences (any word, not just old words) */
.tap-word { cursor: pointer; }
.example-sentence .tap-word:not(.highlight-word),
.preview-example .tap-word:not(.highlight-word) {
  border-bottom: 1px dotted #94a3b8;
}
.example-sentence .tap-word:hover,
.preview-example .tap-word:hover,
.example-sentence .tap-word:focus,
.preview-example .tap-word:focus {
  background: rgba(99, 102, 241, 0.12);
  border-radius: 3px;
  outline: none;
}