/* ============================================
   CppLearner · 错题本视图
   ============================================ */

/* 主布局 */
.wb-layout {
  max-width: 860px;
  margin: 0 auto;
  padding: calc(var(--header-h) + 40px) 32px 80px;
  min-height: 100vh;
}

/* ---- 页头 ---- */
.wb-header {
  margin-bottom: 32px;
  padding-bottom: 24px;
  border-bottom: 2px solid var(--paper-line);
}
.wb-title {
  font-family: var(--font-serif);
  font-size: 28px;
  font-weight: 700;
  color: var(--ink-deep);
  margin-bottom: 6px;
  display: flex;
  align-items: center;
  gap: 12px;
}
.wb-title-icon {
  font-size: 22px;
}
.wb-subtitle {
  font-size: 14px;
  color: var(--ink-mute);
}
.wb-stats {
  display: flex;
  gap: 24px;
  margin-top: 16px;
  flex-wrap: wrap;
}
.wb-stat {
  display: flex;
  flex-direction: column;
  align-items: center;
  background: var(--paper-warm);
  border: 1px solid var(--paper-line);
  border-radius: 4px;
  padding: 10px 20px;
  min-width: 80px;
}
.wb-stat-num {
  font-family: var(--font-serif);
  font-size: 26px;
  font-weight: 700;
  color: var(--vermilion);
  line-height: 1;
}
.wb-stat-label {
  font-size: 12px;
  color: var(--ink-mute);
  margin-top: 4px;
}

/* ---- 工具栏 ---- */
.wb-toolbar {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 24px;
  flex-wrap: wrap;
}
.wb-filter-label {
  font-size: 13px;
  color: var(--ink-mute);
  white-space: nowrap;
}
.wb-filter-btn {
  height: 30px;
  padding: 0 14px;
  border: 1.5px solid var(--paper-line);
  border-radius: 20px;
  background: transparent;
  font-family: var(--font-sans);
  font-size: 13px;
  color: var(--ink-soft);
  cursor: pointer;
  transition: all 0.15s;
  white-space: nowrap;
}
.wb-filter-btn:hover {
  border-color: var(--jade);
  color: var(--jade);
}
.wb-filter-btn.active {
  background: var(--jade);
  border-color: var(--jade);
  color: #fff;
  font-weight: 600;
}
.wb-clear-btn {
  height: 30px;
  padding: 0 14px;
  border: 1.5px solid var(--paper-line);
  border-radius: 3px;
  background: transparent;
  font-size: 13px;
  color: var(--ink-mute);
  cursor: pointer;
  transition: all 0.15s;
  margin-left: auto;
}
.wb-clear-btn:hover {
  border-color: var(--vermilion);
  color: var(--vermilion);
}

/* ---- 空状态 ---- */
.wb-empty {
  text-align: center;
  padding: 80px 20px;
  color: var(--ink-mute);
}
.wb-empty-icon {
  font-size: 48px;
  margin-bottom: 16px;
  opacity: 0.4;
}
.wb-empty-title {
  font-family: var(--font-serif);
  font-size: 20px;
  color: var(--ink-soft);
  margin-bottom: 8px;
}
.wb-empty-text {
  font-size: 14px;
  line-height: 1.8;
}

/* ---- 章节分组标题 ---- */
.wb-group-header {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 28px 0 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--paper-line);
}
.wb-group-title {
  font-family: var(--font-serif);
  font-size: 15px;
  font-weight: 700;
  color: var(--jade);
  flex: 1;
}
.wb-group-count {
  font-size: 12px;
  color: var(--ink-mute);
  background: var(--paper-warm);
  border: 1px solid var(--paper-line);
  border-radius: 20px;
  padding: 2px 10px;
}

/* ---- 错题卡片 ---- */
.wb-card {
  background: var(--paper);
  border: 1.5px solid var(--paper-line);
  border-radius: 4px;
  margin-bottom: 14px;
  overflow: hidden;
  transition: border-color 0.15s, box-shadow 0.15s;
}
.wb-card:hover {
  border-color: #c8bfaa;
  box-shadow: 0 2px 12px rgba(26,41,37,0.06);
}
.wb-card.redo-mode {
  border-color: var(--jade);
  box-shadow: 0 0 0 3px rgba(45,90,74,0.1);
}

/* 卡片头部 */
.wb-card-head {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 16px 18px 14px;
  background: var(--paper-warm);
  border-bottom: 1px solid var(--paper-line);
}
.wb-card-meta {
  flex: 1;
  min-width: 0;
}
.wb-card-tags {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-bottom: 8px;
  flex-wrap: wrap;
}
.wb-tag {
  font-size: 11px;
  padding: 2px 8px;
  border-radius: 3px;
  font-weight: 600;
  letter-spacing: 0.3px;
}
.wb-tag-chapter {
  background: var(--jade-glow);
  color: var(--jade);
}
.wb-tag-topic {
  background: var(--paper-deep);
  color: var(--ink-soft);
}
.wb-tag-wrong-count {
  background: var(--vermilion-bg);
  color: var(--vermilion);
}
.wb-tag-multi {
  background: var(--gold-bg);
  color: var(--gold);
}
.wb-card-question {
  font-size: 15px;
  color: var(--ink-deep);
  line-height: 1.65;
  font-weight: 500;
}
.wb-card-actions {
  display: flex;
  gap: 8px;
  flex-shrink: 0;
  align-items: flex-start;
}
.wb-action-btn {
  height: 30px;
  padding: 0 12px;
  border-radius: 3px;
  border: 1.5px solid var(--paper-line);
  background: var(--paper);
  font-family: var(--font-sans);
  font-size: 12px;
  cursor: pointer;
  transition: all 0.15s;
  white-space: nowrap;
  font-weight: 500;
}
.wb-action-btn.redo {
  color: var(--jade);
  border-color: var(--jade);
}
.wb-action-btn.redo:hover {
  background: var(--jade);
  color: #fff;
}
.wb-action-btn.remove {
  color: var(--ink-mute);
}
.wb-action-btn.remove:hover {
  border-color: var(--vermilion);
  color: var(--vermilion);
}
.wb-action-btn.cancel {
  color: var(--ink-mute);
}
.wb-action-btn.cancel:hover {
  border-color: var(--ink-soft);
  color: var(--ink-soft);
}

/* 卡片内容（答案区）*/
.wb-card-body {
  padding: 14px 18px 16px;
}

/* 选项 (只读展示) */
.wb-option {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 8px 12px;
  border-radius: 3px;
  margin-bottom: 6px;
  font-size: 14px;
  border: 1.5px solid transparent;
}
.wb-option.correct {
  background: rgba(45,90,74,0.06);
  border-color: var(--jade);
  color: var(--jade);
}
.wb-option.my-wrong {
  background: var(--vermilion-bg);
  border-color: var(--vermilion);
  color: var(--vermilion);
}
.wb-option.neutral {
  color: var(--ink-soft);
}
.wb-option-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  border: 1.5px solid currentColor;
  font-size: 12px;
  font-weight: 700;
  flex-shrink: 0;
  margin-top: 1px;
}
.wb-option.correct .wb-option-mark { background: var(--jade); color: #fff; border-color: var(--jade); }
.wb-option.my-wrong .wb-option-mark { background: var(--vermilion); color: #fff; border-color: var(--vermilion); }
.wb-option-label { display: inline; }

/* 解析框 */
.wb-explanation {
  margin-top: 12px;
  padding: 12px 14px;
  background: var(--jade-glow);
  border-left: 3px solid var(--jade);
  border-radius: 0 3px 3px 0;
  font-size: 13.5px;
  color: var(--ink-soft);
  line-height: 1.75;
}
.wb-explanation-label {
  font-weight: 700;
  color: var(--jade);
  margin-bottom: 4px;
  font-size: 12px;
  letter-spacing: 0.5px;
}

/* ---- 重做模式中的交互选项 ---- */
.wb-redo-option {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 9px 14px;
  border-radius: 3px;
  margin-bottom: 6px;
  cursor: pointer;
  border: 1.5px solid var(--paper-line);
  font-size: 14px;
  color: var(--ink-soft);
  transition: all 0.15s;
}
.wb-redo-option:hover { border-color: var(--jade-soft); color: var(--ink-deep); }
.wb-redo-option.selected { border-color: var(--jade); background: var(--jade-glow); color: var(--jade); }
.wb-redo-option.disabled { pointer-events: none; }
.wb-redo-option.result-correct { border-color: var(--jade); background: rgba(45,90,74,0.08); color: var(--jade); }
.wb-redo-option.result-wrong { border-color: var(--vermilion); background: var(--vermilion-bg); color: var(--vermilion); }
.wb-redo-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 22px; height: 22px;
  border-radius: 3px;
  border: 1.5px solid currentColor;
  font-size: 12px;
  font-weight: 700;
  flex-shrink: 0;
  margin-top: 1px;
}
.wb-redo-option.selected .wb-redo-mark { background: var(--jade); color: #fff; }
.wb-redo-option.result-correct .wb-redo-mark { background: var(--jade); color: #fff; border-radius: 50%; }
.wb-redo-option.result-wrong .wb-redo-mark { background: var(--vermilion); color: #fff; border-radius: 50%; }

.wb-redo-hint {
  font-size: 12px;
  color: var(--ink-mute);
  margin-bottom: 8px;
  font-style: italic;
}
.wb-redo-submit {
  height: 36px;
  padding: 0 20px;
  background: var(--jade);
  color: #fff;
  border: none;
  border-radius: 3px;
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  margin-top: 4px;
  transition: background 0.15s;
}
.wb-redo-submit:hover { background: var(--jade-soft); }
.wb-redo-submit:disabled { opacity: 0.4; cursor: not-allowed; }

.wb-redo-result {
  margin-top: 12px;
  padding: 10px 14px;
  border-radius: 3px;
  font-size: 13px;
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 8px;
}
.wb-redo-result.correct { background: rgba(45,90,74,0.1); color: var(--jade); }
.wb-redo-result.wrong   { background: var(--vermilion-bg); color: var(--vermilion); }

/* 最后答题时间 */
.wb-last-time {
  font-size: 12px;
  color: var(--ink-mute);
  margin-top: 10px;
  text-align: right;
}

/* 加载旋转动画 */
@keyframes wb-spin {
  from { transform: rotate(0deg); }
  to   { transform: rotate(360deg); }
}
.wb-loading-spinner {
  width: 36px;
  height: 36px;
  border: 3px solid var(--paper-line);
  border-top-color: var(--jade);
  border-radius: 50%;
  animation: wb-spin 0.8s linear infinite;
  margin: 0 auto;
}

@media (max-width: 700px) {
  .wb-layout { padding: calc(var(--header-h) + 24px) 16px 80px; }
  .wb-title { font-size: 22px; }
  .wb-card-head { flex-direction: column; gap: 10px; }
  .wb-card-actions { flex-direction: row; }
}