/* 循环复习 + 平均掌握度样式（只在章节页使用；views.css 不动）。
 * index.html 里在 views.css 之后加载，因此可以覆盖 .chaptertabs 的 3 等分为 4 等分。 */

/* ---------------- 4 个 tab 等分（390px 不挤、不折行） ---------------- */
.chaptertabs {
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 6px;
}
.chaptertab {
  min-width: 0;
  min-height: 78px;
  padding: 9px 6px;
  gap: 0;
}
.chaptertab-ic { font-size: 15px; margin-bottom: 2px; }
.chaptertab-label {
  font-size: 13px;
  line-height: 1.3;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 100%;
}
.chaptertab-hint {
  font-size: 10px;
  line-height: 1.3;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 100%;
}
.chaptertab[aria-selected="true"] .chaptertab-label { font-size: 13px; }
@media (min-width: 720px) {
  .chaptertab { padding: 10px 10px; min-height: 84px; }
  .chaptertab-label { font-size: 14.5px; }
  .chaptertab-hint { font-size: 11px; }
}

/* ---------------- 章节顶部：平均掌握度 ---------------- */
.chapterhead-mastery { margin-top: 8px; }
.chapterhead-mastery .bar { height: 5px; margin-top: 4px; }
.chapterhead-mastery .bar > i {
  background: linear-gradient(90deg, #34d399, #0ea5e9 60%, #1d4ed8);
}
.chapterhead-mastery.is-empty .bar > i { background: #cbd5e1; }

/* ================= 循环复习组件 ================= */
.loop { display: block; }
.loop + .loop,
.loop > * + * { margin-top: 12px; }
.loop-card {
  background: var(--card, #fff);
  border: 1px solid var(--line, #e6e9f0);
  border-radius: 16px;
  box-shadow: 0 1px 2px rgba(15, 23, 42, .05), 0 8px 24px rgba(15, 23, 42, .06);
  padding: 16px;
}
.loop-muted { color: var(--ink-3, #94a3b8); font-size: 12.5px; line-height: 1.6; }
.loop-note {
  margin-top: 12px;
  color: var(--ink-2, #475569);
  font-size: 12.5px;
  line-height: 1.7;
  background: #f8fafc;
  border-radius: 10px;
  padding: 9px 11px;
}
.loop-foot-note { text-align: center; color: var(--ink-3, #94a3b8); font-size: 12px; margin-top: 8px; }

/* 进度条 */
.loop-bar {
  position: relative;
  height: 10px;
  margin-top: 10px;
  border-radius: 999px;
  background: #eef1f6;
  overflow: hidden;
}
.loop-bar > i {
  display: block;
  height: 100%;
  border-radius: 999px;
  transition: width .35s ease;
  background: linear-gradient(90deg, #fca5a5, #fcd34d 40%, #60a5fa 70%, #34d399);
}
.loop-bar-small { height: 6px; margin-top: 6px; }
.loop-bar-miss > i { background: #f87171; }
.loop-bar-fuzzy > i { background: linear-gradient(90deg, #fb923c, #fbbf24); }
.loop-bar-know > i { background: linear-gradient(90deg, #60a5fa, #3b82f6); }
.loop-bar-solid > i { background: linear-gradient(90deg, #34d399, #059669); }

/* -------- 概览 -------- */
.loop-overview { padding-top: 18px; }
.loop-ov-label { font-size: 12.5px; font-weight: 700; color: var(--ink-2, #475569); letter-spacing: .04em; }
.loop-ov-big {
  display: flex;
  align-items: baseline;
  gap: 3px;
  margin-top: 2px;
  color: var(--ink, #0f172a);
}
.loop-ov-big b { font-size: 46px; line-height: 1; font-weight: 900; letter-spacing: -.02em; font-variant-numeric: tabular-nums; }
.loop-ov-big i { font-style: normal; font-size: 17px; font-weight: 700; color: var(--ink-2, #475569); }
.loop-ov-big.tone-solid b { color: #047857; }
.loop-ov-big.tone-know b { color: #1d4ed8; }
.loop-ov-big.tone-fuzzy b { color: #b45309; }
.loop-ov-big.tone-miss b { color: #b91c1c; }
.loop-ov-sub { margin-top: 4px; font-size: 13px; color: var(--ink-2, #475569); }
.loop-chips { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 12px; }
.loop-chip {
  font-size: 12px;
  font-weight: 600;
  color: var(--ink-2, #475569);
  background: #f1f5f9;
  border-radius: 999px;
  padding: 4px 10px;
}
.loop-chip.miss { background: #fef2f2; color: #b91c1c; }
.loop-chip.muted { color: var(--ink-3, #94a3b8); }
.loop-ov-actions { display: grid; gap: 8px; margin-top: 14px; }
.loop-start { min-height: 50px; font-size: 15.5px; }

/* -------- 复习中 -------- */
.loop-progresscard {
  background: var(--card, #fff);
  border: 1px solid var(--line, #e6e9f0);
  border-radius: 14px;
  padding: 10px 14px;
  box-shadow: 0 1px 2px rgba(15, 23, 42, .05);
}
.loop-progress-top { display: flex; align-items: center; justify-content: space-between; gap: 8px; }
.loop-progress-label { font-size: 13.5px; font-weight: 800; color: var(--ink, #0f172a); font-variant-numeric: tabular-nums; }
.loop-backbtn {
  min-height: 38px;
  padding: 0 10px;
  border: 1px solid var(--line, #e6e9f0);
  border-radius: 9px;
  background: #fff;
  color: var(--ink-2, #475569);
  font-size: 12.5px;
  font-weight: 700;
  cursor: pointer;
}
.loop-backbtn:active { background: #f8fafc; }
.loop-progressbar {
  height: 6px;
  margin-top: 8px;
  border-radius: 999px;
  background: #eef1f6;
  overflow: hidden;
}
.loop-progressbar > i {
  display: block;
  height: 100%;
  border-radius: 999px;
  background: linear-gradient(90deg, #1d4ed8, #0ea5e9);
  transition: width .3s ease;
}

.loop-review { padding: 18px 16px; }
.loop-card-top { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.loop-kind {
  font-size: 11.5px;
  font-weight: 800;
  border-radius: 6px;
  padding: 2px 8px;
  background: #eef2ff;
  color: #3730a3;
}
.loop-kind-concept { background: #ecfeff; color: #0e7490; }
.loop-kind-term { background: #f0fdf4; color: #15803d; }
.loop-kind-short { background: #fff7ed; color: #c2410c; }
.loop-kind-case { background: #fdf2f8; color: #a21caf; }
.loop-page-tag { font-size: 11.5px; color: var(--ink-3, #94a3b8); }
.loop-mastery-tag {
  margin-left: auto;
  font-size: 11.5px;
  font-weight: 700;
  border-radius: 999px;
  padding: 2px 9px;
  background: #f1f5f9;
  color: var(--ink-2, #475569);
}
.loop-mastery-tag.tone-solid { background: #ecfdf5; color: #047857; }
.loop-mastery-tag.tone-know { background: #eff6ff; color: #1d4ed8; }
.loop-mastery-tag.tone-fuzzy { background: #fffbeb; color: #b45309; }
.loop-mastery-tag.tone-miss { background: #fef2f2; color: #b91c1c; }

.loop-front {
  margin: 14px 0 4px;
  font-size: 17px;
  font-weight: 800;
  line-height: 1.55;
  color: var(--ink, #0f172a);
  word-break: break-word;
}
.loop-reveal {
  width: 100%;
  min-height: 46px;
  margin-top: 12px;
  border: 1px dashed #c7d2fe;
  border-radius: 12px;
  background: #f8faff;
  color: #1e3a8a;
  font-size: 14px;
  font-weight: 700;
  cursor: pointer;
}
.loop-reveal:active { background: #eef2ff; }
.loop-answer { margin-top: 12px; }
.loop-answer[hidden] { display: none !important; }
.loop-section {
  background: #f8fafc;
  border: 1px solid #eef1f6;
  border-radius: 12px;
  padding: 10px 12px;
}
.loop-section + .loop-section { margin-top: 8px; }
.loop-section-label {
  margin: 0 0 4px;
  font-size: 12px;
  font-weight: 800;
  color: var(--ink-2, #475569);
}
.loop-section-label::before { content: "▪ "; color: var(--brand, #1d4ed8); }
.loop-section-text { font-size: 14.5px; line-height: 1.75; color: var(--ink, #1f2937); white-space: pre-wrap; word-break: break-word; }
.loop-back { font-size: 14.5px; line-height: 1.75; color: var(--ink, #1f2937); white-space: pre-wrap; word-break: break-word; }
.loop-page-link { display: inline-block; margin-top: 8px; font-size: 12.5px; font-weight: 600; color: var(--brand, #1d4ed8); }

.loop-grades {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 6px;
  margin-top: 16px;
}
.loop-grades[hidden] { display: none !important; }
.loop-grade {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1px;
  min-height: 58px;
  padding: 8px 4px;
  border-radius: 12px;
  border: 1.5px solid #e6e9f0;
  background: #fff;
  cursor: pointer;
}
.loop-grade:active { transform: scale(.97); }
.loop-grade b { font-size: 14.5px; font-weight: 800; }
.loop-grade span { font-size: 10.5px; color: var(--ink-3, #94a3b8); }
.loop-grade-miss { border-color: #fecaca; background: #fff5f5; }
.loop-grade-miss b { color: #b91c1c; }
.loop-grade-fuzzy { border-color: #fde68a; background: #fffbeb; }
.loop-grade-fuzzy b { color: #b45309; }
.loop-grade-know { border-color: #bfdbfe; background: #eff6ff; }
.loop-grade-know b { color: #1d4ed8; }
.loop-grade-solid { border-color: #a7f3d0; background: #ecfdf5; }
.loop-grade-solid b { color: #047857; }

.loop-reviewfoot { display: flex; align-items: center; justify-content: space-between; gap: 10px; }
.loop-skip {
  min-height: 44px;
  padding: 0 8px;
  border: 0;
  background: transparent;
  color: var(--ink-2, #475569);
  font-size: 13px;
  font-weight: 700;
  cursor: pointer;
  text-decoration: underline;
  text-underline-offset: 3px;
}
.loop-kbdhint { font-size: 11px; color: var(--ink-3, #94a3b8); }

/* -------- 本轮结束 -------- */
.loop-done { padding: 20px 16px; text-align: center; }
.loop-done-emoji { font-size: 34px; line-height: 1; }
.loop-done-title { margin-top: 8px; font-size: 19px; font-weight: 900; color: var(--ink, #0f172a); }
.loop-done .loop-muted { margin-top: 6px; }
.loop-stats { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; margin-top: 14px; }
.loop-stat {
  border-radius: 12px;
  padding: 10px 4px;
  background: #f8fafc;
  border: 1px solid #eef1f6;
}
.loop-stat b { display: block; font-size: 22px; font-weight: 900; line-height: 1.15; font-variant-numeric: tabular-nums; }
.loop-stat span { font-size: 11.5px; color: var(--ink-3, #94a3b8); }
.loop-stat.tone-solid b { color: #047857; }
.loop-stat.tone-fuzzy b { color: #b45309; }
.loop-stat.tone-miss b { color: #b91c1c; }
.loop-done-avg { margin-top: 14px; text-align: left; }
.loop-done-row {
  display: flex;
  align-items: baseline;
  gap: 8px;
  font-size: 13.5px;
  color: var(--ink-2, #475569);
  padding: 4px 0;
}
.loop-done-row b { margin-left: auto; font-size: 15px; color: var(--ink, #0f172a); font-variant-numeric: tabular-nums; }
.loop-done-row b.tone-solid { color: #047857; }
.loop-done-row b.tone-know { color: #1d4ed8; }
.loop-delta { font-style: normal; font-size: 12px; font-weight: 800; }
.loop-delta.up { color: #047857; }
.loop-delta.down { color: #b91c1c; }
.loop-savehint { margin-top: 10px; }
.loop-saverow { display: flex; align-items: center; justify-content: center; gap: 10px; margin-top: 10px; }
.loop-done-actions { display: grid; gap: 8px; margin-top: 16px; }
.loop-done-actions .btn.wide { min-height: 46px; }

/* -------- 空状态 / 加载 -------- */
.loop-empty { text-align: center; padding: 24px 16px; }
.loop-empty-ic { font-size: 30px; color: var(--ink-3, #94a3b8); }
.loop-empty h3 { margin-top: 6px; font-size: 16.5px; color: var(--ink, #0f172a); }
.loop-empty .loop-muted { margin-top: 6px; }
.loop-empty-actions { display: grid; gap: 8px; margin-top: 14px; }
.loop-loading { text-align: center; padding: 26px 16px; }
.loop-skeleton {
  height: 54px;
  border-radius: 12px;
  background: linear-gradient(90deg, #eef1f6, #e2e8f0, #eef1f6);
  animation: loop-sk 1.3s ease-in-out infinite;
}
@keyframes loop-sk {
  0%, 100% { opacity: .55; }
  50% { opacity: 1; }
}

@media (max-width: 360px) {
  .chaptertab-label { font-size: 12.5px; }
  .chaptertab-hint { font-size: 9.5px; }
  .loop-ov-big b { font-size: 40px; }
  .loop-grade b { font-size: 13.5px; }
  .loop-grade span { display: none; }
}