:root {
  --kanji-primary: #4fcf66;
  --kanji-primary-dark: #2ea94a;
  --kanji-primary-soft: #edf9ef;
  --kanji-primary-pale: #fbfff3;
  --kanji-blue: #3b82f6;
  --kanji-red: #ef4444;
  --kanji-yellow: #f2b824;
  --kanji-purple: #8b5cf6;
  --kanji-ink: #172033;
  --kanji-muted: #6f7788;
  --kanji-line: #e7eaf0;
  --kanji-card: #ffffff;
  --kanji-page: #f8f9fc;
  --kanji-shadow: 0 18px 45px rgba(31, 41, 55, 0.08);
}

* { box-sizing: border-box; }

.n4-kanji-page [hidden] { display: none !important; }

body.n4-kanji-page {
  min-height: 100vh;
  margin: 0;
  overflow-x: hidden;
  color: var(--kanji-ink);
  background:
    radial-gradient(circle at 11% 7%, rgba(126, 219, 122, 0.15), transparent 25%),
    radial-gradient(circle at 94% 16%, rgba(185, 244, 191, 0.24), transparent 23%),
    var(--kanji-page);
  font-family: "Poppins", "Noto Sans JP", sans-serif;
}

.n4-kanji-page button,
.n4-kanji-page input { font: inherit; }

.n4-kanji-page .level-new-header {
  position: sticky;
  top: 0;
  z-index: 1200;
}

.visually-hidden {
  position: absolute !important;
  width: 1px !important;
  height: 1px !important;
  padding: 0 !important;
  margin: -1px !important;
  overflow: hidden !important;
  clip: rect(0 0 0 0) !important;
  white-space: nowrap !important;
  border: 0 !important;
}

.kanji-page-shell {
  width: min(1480px, calc(100% - 44px));
  margin: 0 auto;
  padding: 28px 0 56px;
  display: grid;
  grid-template-columns: 252px minmax(0, 1fr) 306px;
  gap: 22px;
  align-items: start;
  transition: grid-template-columns .24s ease;
}

.kanji-left-sidebar,
.kanji-right-sidebar {
  position: sticky;
  top: 104px;
  min-width: 0;
}

.kanji-left-sidebar {
  display: grid;
  gap: 14px;
  max-height: calc(100vh - 126px);
  overflow: visible;
}

.lesson-sidebar-toggle {
  position: absolute;
  z-index: 8;
  top: 18px;
  right: -16px;
  display: grid;
  width: 34px;
  height: 34px;
  place-items: center;
  padding: 0;
  border: 1px solid #cfe8d3;
  border-radius: 50%;
  color: #387947;
  background: #fff;
  box-shadow: 0 7px 18px rgba(40, 89, 52, .15);
  cursor: pointer;
  transition: transform .22s ease, background .22s ease, color .22s ease;
}

.lesson-sidebar-toggle:hover { transform: translateY(-1px); color: #fff; background: var(--kanji-primary); }
.lesson-sidebar-toggle svg { width: 18px; height: 18px; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; transition: transform .24s ease; }

.kanji-sidebar-card,
.kanji-side-card,
.kanji-workspace {
  border: 1px solid rgba(221, 226, 235, .94);
  background: rgba(255, 255, 255, .95);
  box-shadow: var(--kanji-shadow);
  backdrop-filter: blur(18px);
}

.kanji-sidebar-card { padding: 15px; border-radius: 23px; }

.kanji-sidebar-heading {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 4px 4px 15px;
  border-bottom: 1px solid #edf0f4;
}

.kanji-sidebar-heading.is-compact { padding-bottom: 12px; }
.kanji-sidebar-heading-icon {
  display: grid;
  width: 44px;
  height: 44px;
  flex: 0 0 44px;
  place-items: center;
  border-radius: 14px;
  color: #fff;
  background: linear-gradient(145deg, #86e58b, var(--kanji-primary));
  box-shadow: 0 9px 20px rgba(79, 207, 102, .22);
}
.kanji-sidebar-heading-icon svg { width: 23px; height: 23px; fill: none; stroke: currentColor; stroke-width: 1.9; stroke-linecap: round; stroke-linejoin: round; }
.kanji-sidebar-heading span { color: var(--kanji-primary-dark); font-size: 10px; font-weight: 800; letter-spacing: .07em; text-transform: uppercase; }
.kanji-sidebar-heading h2 { margin: 2px 0 0; font-size: 16px; }

.kanji-lesson-list { display: grid; gap: 8px; padding-top: 12px; }

/* Cuộn toàn bộ khung sidebar, không thay đổi kích thước/cấu trúc các card submenu. */
.kanji-lesson-card {
  max-height: calc(100vh - 126px);
  overflow-x: hidden;
  overflow-y: auto;
  overscroll-behavior: contain;
  scrollbar-width: thin;
  scrollbar-color: #b8ddc0 transparent;
  touch-action: pan-y;
}

.kanji-lesson-card::-webkit-scrollbar {
  width: 7px;
}

.kanji-lesson-card::-webkit-scrollbar-track {
  background: transparent;
}

.kanji-lesson-card::-webkit-scrollbar-thumb {
  border: 2px solid transparent;
  border-radius: 999px;
  background: #b8ddc0;
  background-clip: padding-box;
}

.kanji-lesson-card::-webkit-scrollbar-thumb:hover {
  background: #86c993;
  background-clip: padding-box;
}


.kanji-lesson-group {
  overflow: hidden;
  border: 1px solid #e5e9ee;
  border-radius: 17px;
  background: #fbfcfd;
  transition: border-color .2s ease, box-shadow .2s ease;
}
.kanji-lesson-group.is-open { border-color: #cfe8d3; box-shadow: 0 8px 18px rgba(46,169,74,.07); }
.kanji-lesson-parent {
  display: grid;
  grid-template-columns: 48px minmax(0, 1fr) 20px;
  gap: 10px;
  align-items: center;
  width: 100%;
  min-height: 64px;
  padding: 9px 11px;
  border: 0;
  color: var(--kanji-ink);
  background: transparent;
  text-align: left;
  cursor: pointer;
  transition: background .2s ease;
}
.kanji-lesson-parent:hover { background: #f4fbf5; }
.kanji-lesson-parent-number {
  display: grid;
  width: 46px;
  height: 42px;
  place-items: center;
  border-radius: 12px;
  color: #fff;
  background: linear-gradient(145deg, #79df82, var(--kanji-primary));
  font-size: 10px;
  font-weight: 900;
}
.kanji-lesson-parent-copy { min-width: 0; }
.kanji-lesson-parent-copy strong { display: block; font-size: 12px; }
.kanji-lesson-parent-copy small { display: block; margin-top: 3px; color: #8d96a3; font-size: 9px; font-weight: 600; }
.kanji-lesson-chevron {
  width: 19px;
  height: 19px;
  fill: none;
  stroke: #758090;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
  transition: transform .22s ease;
}
.kanji-lesson-group.is-open .kanji-lesson-chevron { transform: rotate(180deg); }
.kanji-lesson-submenu {
  display: grid;
  gap: 7px;
  max-height: 260px;
  padding: 8px 8px 9px 22px;
  border-top: 1px solid #edf1ee;
  opacity: 1;
  transition: max-height .24s ease, padding .24s ease, opacity .18s ease;
}
.kanji-lesson-group:not(.is-open) .kanji-lesson-submenu {
  max-height: 0;
  padding-top: 0;
  padding-bottom: 0;
  border-top-color: transparent;
  opacity: 0;
  pointer-events: none;
}
.kanji-lesson-submenu .kanji-lesson-item { min-height: 57px; }

.kanji-lesson-item {
  display: grid;
  grid-template-columns: 42px minmax(0, 1fr) auto;
  gap: 10px;
  align-items: center;
  width: 100%;
  min-height: 62px;
  padding: 9px 10px;
  border: 1px solid #e8ebf0;
  border-radius: 15px;
  color: var(--kanji-ink);
  background: #fff;
  text-align: left;
  cursor: pointer;
  transition: transform .2s ease, border-color .2s ease, background .2s ease;
}
.kanji-lesson-item:hover { transform: translateX(2px); border-color: #b9e6bf; background: #f8fff9; }
.kanji-lesson-item.is-active { border-color: #a8e0b0; background: linear-gradient(135deg, #f0fbf2, #e2f6e6); box-shadow: 0 8px 18px rgba(79, 207, 102, .1); }
.kanji-lesson-number { display: grid; width: 40px; height: 40px; place-items: center; border-radius: 12px; color: #747b88; background: #f2f4f7; font-size: 10px; font-weight: 900; }
.kanji-lesson-item.is-active .kanji-lesson-number { color: #fff; background: linear-gradient(145deg, #79df82, var(--kanji-primary)); }
.kanji-lesson-copy { min-width: 0; }
.kanji-lesson-copy strong { display: block; font-family: "Noto Sans JP", sans-serif; font-size: 13px; }
.kanji-lesson-copy small { display: block; overflow: hidden; margin-top: 3px; color: #9097a4; font-size: 9px; font-weight: 600; text-overflow: ellipsis; white-space: nowrap; }
.kanji-lesson-star { color: #f6b81f; font-size: 13px; }


.kanji-workspace {
  min-width: 0;
  padding: 26px;
  border-radius: 24px;
}

.kanji-page-heading {
  display: flex;
  align-items: center;
  gap: 15px;
  margin-bottom: 22px;
}
.kanji-level-badge {
  display: grid;
  width: 64px;
  height: 64px;
  flex: 0 0 64px;
  place-items: center;
  border-radius: 21px;
  color: #fff;
  background: linear-gradient(145deg, #8be890, var(--kanji-primary));
  box-shadow: 0 14px 28px rgba(79, 207, 102, .25), inset 0 1px 0 rgba(255,255,255,.5);
  font-size: 20px;
  font-weight: 900;
}
.kanji-page-heading h1 { margin: 0; font-size: clamp(24px, 3vw, 34px); line-height: 1.2; }
.kanji-page-heading p { margin: 5px 0 0; color: var(--kanji-muted); font-size: 13px; }

#kanjiStudySection,
#kanjiReviewSection { scroll-margin-top: 96px; }

.kanji-study-card,
.kanji-reading-section,
.kanji-review-section {
  overflow: hidden;
  border: 1px solid #dce9de;
  border-radius: 24px;
  background: linear-gradient(180deg, #fff, #fbfefb);
  box-shadow: 0 15px 35px rgba(47, 92, 57, .07);
}

.kanji-progress-row {
  display: grid;
  grid-template-columns: auto minmax(100px, 1fr) 48px;
  gap: 18px;
  align-items: center;
  min-height: 72px;
  padding: 0 24px;
  border-bottom: 1px solid #e9eee9;
}
.kanji-progress-row strong { font-size: 12px; }
.kanji-progress-row strong span:last-child { color: var(--kanji-primary-dark); }
.kanji-progress-row > span { color: #344054; font-size: 11px; font-weight: 900; text-align: right; }
.kanji-progress-track { height: 9px; overflow: hidden; border-radius: 999px; background: #e5e7eb; }
.kanji-progress-track span { display: block; width: 0; height: 100%; border-radius: inherit; background: linear-gradient(90deg, #7edb7a, var(--kanji-primary)); transition: width .35s ease; }

.kanji-review-launch {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 14px;
  align-items: center;
  width: calc(100% - 40px);
  min-height: 72px;
  margin: 18px 20px 0;
  padding: 13px 18px;
  border: 1px solid #a8e0b0;
  border-radius: 18px;
  color: #17652d;
  background: linear-gradient(135deg, #effaf1, #dcf4e1);
  text-align: left;
  cursor: pointer;
  box-shadow: 0 10px 24px rgba(79, 207, 102, .13);
}
.kanji-review-launch:hover { transform: translateY(-1px); }
.kanji-review-launch-jp { display: grid; width: 48px; height: 48px; place-items: center; border-radius: 15px; color: #fff; background: var(--kanji-primary-dark); font-family: "Noto Sans JP", sans-serif; font-size: 15px; font-weight: 900; }
.kanji-review-launch > span:nth-child(2) { font-size: 14px; font-weight: 800; }
.kanji-review-launch svg { width: 22px; height: 22px; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }

.kanji-card-stage { padding: 30px 28px 20px; }
.kanji-learning-card {
  position: relative;
  width: min(700px, 100%);
  min-height: 455px;
  margin: 0 auto;
  padding: 24px 30px 28px;
  border: 1px solid #cfe8d3;
  border-radius: 28px;
  background:
    radial-gradient(circle at 12% 8%, rgba(126,219,122,.13), transparent 27%),
    radial-gradient(circle at 92% 86%, rgba(185,244,191,.23), transparent 24%),
    #fff;
  box-shadow: 0 22px 45px rgba(31, 70, 39, .12), 0 7px 0 #e2f6e6;
}
.kanji-card-topline { display: flex; justify-content: space-between; gap: 14px; align-items: center; padding-right: 55px; }
.kanji-card-unit { display: inline-flex; align-items: center; min-height: 32px; padding: 0 12px; border-radius: 999px; color: #267d3c; background: #e8f8eb; font-size: 10px; font-weight: 800; }
.kanji-stroke-count { color: #7b8492; font-size: 10px; }
.kanji-stroke-count strong { color: #394150; font-size: 13px; }

.kanji-difficult-toggle {
  position: absolute;
  z-index: 3;
  top: 20px;
  right: 22px;
  display: grid;
  width: 42px;
  height: 42px;
  place-items: center;
  padding: 0;
  border: 1px solid #e4e7ec;
  border-radius: 13px;
  color: #9aa2af;
  background: #fff;
  cursor: pointer;
  transition: .2s ease;
}
.kanji-difficult-toggle:hover { color: #ef4444; border-color: #fecaca; background: #fff7f7; }
.kanji-difficult-toggle.is-active { color: #ef4444; border-color: #fecaca; background: #fff1f2; box-shadow: 0 7px 18px rgba(239,68,68,.12); }
.kanji-difficult-toggle svg { width: 22px; height: 22px; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linejoin: round; }
.kanji-difficult-toggle.is-active svg { fill: currentColor; }

.kanji-character-wrap { display: grid; place-items: center; min-height: 230px; padding: 18px 0 10px; }
.kanji-character { font-family: "Noto Sans JP", sans-serif; font-size: clamp(112px, 13vw, 170px); font-weight: 800; line-height: 1; letter-spacing: .02em; }
.kanji-speaker-button {
  display: grid;
  width: 50px;
  height: 50px;
  place-items: center;
  margin-top: 14px;
  padding: 0;
  border: 1px solid #a8e0b0;
  border-radius: 50%;
  color: var(--kanji-primary-dark);
  background: #f5fcf6;
  cursor: pointer;
  transition: .2s ease;
}
.kanji-speaker-button:hover { color: #fff; background: var(--kanji-primary); transform: translateY(-1px); }
.kanji-speaker-button svg { width: 23px; height: 23px; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }

.kanji-reading-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 14px; }
.kanji-reading-panel { min-height: 112px; padding: 17px 18px; border: 1px solid #e2e8e3; border-radius: 18px; }
.kanji-reading-panel.is-on { background: linear-gradient(135deg, #f2f7ff, #fbfdff); border-color: #d7e4fa; }
.kanji-reading-panel.is-kun { background: linear-gradient(135deg, #f1fbf3, #fbfffc); border-color: #cfe9d3; }
.kanji-reading-label { display: flex; align-items: baseline; gap: 8px; }
.kanji-reading-label strong { font-family: "Noto Sans JP", sans-serif; font-size: 13px; }
.kanji-reading-label small { color: #8992a1; font-size: 9px; font-weight: 700; }
.kanji-reading-values { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 14px; }
.kanji-reading-value { display: inline-flex; align-items: center; min-height: 32px; padding: 0 11px; border-radius: 10px; font-family: "Noto Sans JP", sans-serif; font-size: 15px; font-weight: 800; }
.is-on .kanji-reading-value { color: #2c66b8; background: #eaf2ff; }
.is-kun .kanji-reading-value { color: #24733a; background: #e7f7ea; }
.kanji-reading-empty { color: #9aa2af; font-size: 12px; font-style: italic; }
.kanji-card-counter { position: absolute; right: 27px; bottom: 17px; color: #838b98; font-size: 11px; font-weight: 800; }

.kanji-primary-actions { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 13px; padding: 0 28px 28px; }
.kanji-answer-button {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  min-height: 57px;
  padding: 0 16px;
  border-radius: 16px;
  font-size: 12px;
  font-weight: 800;
  cursor: pointer;
  transition: transform .2s ease, box-shadow .2s ease;
}
.kanji-answer-button:hover { transform: translateY(-2px); }
.kanji-answer-button.is-review { color: #d23838; border: 1px solid #fecaca; background: #fff5f5; }
.kanji-answer-button.is-remembered { color: #fff; border: 1px solid var(--kanji-primary-dark); background: linear-gradient(145deg, #6edb78, var(--kanji-primary-dark)); box-shadow: 0 10px 20px rgba(46,169,74,.18); }
.kanji-answer-button.is-next { color: #17652d; border: 1px solid #b9e6bf; background: #effaf1; }
.kanji-answer-button svg { width: 19px; height: 19px; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }
.kanji-answer-button:disabled { opacity: .46; cursor: not-allowed; transform: none; box-shadow: none; }

.kanji-reading-section { margin-top: 20px; }
.kanji-section-heading {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  align-items: center;
  padding: 19px 22px;
  border-bottom: 1px solid #e8eee9;
}
.kanji-section-heading > div { display: flex; align-items: center; gap: 12px; }
.kanji-section-icon { display: grid; width: 43px; height: 43px; place-items: center; border-radius: 14px; color: #fff; background: linear-gradient(145deg, #7edb7a, var(--kanji-primary)); font-family: "Noto Sans JP", sans-serif; font-weight: 900; }
.kanji-section-heading h2 { margin: 0; font-family: "Noto Sans JP", sans-serif; font-size: 18px; }
.kanji-section-heading p { margin: 3px 0 0; color: var(--kanji-muted); font-size: 10px; }
.kanji-reading-hint { color: #7d8796; font-size: 9px; font-weight: 700; }
.kanji-reading-practice-list { display: grid; gap: 9px; padding: 18px 20px 22px; }
.kanji-reading-row {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr) auto;
  gap: 12px;
  align-items: center;
  width: 100%;
  min-height: 57px;
  padding: 10px 13px;
  border: 1px solid #e6eae7;
  border-radius: 14px;
  color: var(--kanji-ink);
  background: #fff;
  text-align: left;
  cursor: pointer;
  transition: .2s ease;
}
.kanji-reading-row:hover { border-color: #b9e6bf; background: #f9fdfa; }
.kanji-reading-index { display: grid; width: 30px; height: 30px; place-items: center; border-radius: 10px; color: #267d3c; background: #e8f8eb; font-size: 10px; font-weight: 900; }
.kanji-reading-sentence { font-family: "Noto Sans JP", sans-serif; font-size: 13px; line-height: 1.75; }
.kanji-reading-sentence mark,
.kanji-review-sentence mark { padding: 1px 2px; color: inherit; background: transparent; border-bottom: 2px solid var(--kanji-primary); font-weight: 800; }
.kanji-reading-answer { min-width: 120px; padding: 7px 10px; border-radius: 10px; color: #8b94a1; background: #f4f6f8; font-family: "Noto Sans JP", sans-serif; font-size: 11px; font-weight: 700; text-align: center; }
.kanji-reading-row.is-revealed .kanji-reading-answer { color: #24733a; background: #e7f7ea; }

.kanji-review-section { margin-top: 0; }
.kanji-review-header { display: flex; align-items: center; justify-content: space-between; gap: 20px; padding: 24px; border-bottom: 1px solid #e6ece7; background: linear-gradient(135deg, #f3fcf4, #fff); }
.kanji-review-header > div > span { color: var(--kanji-primary-dark); font-family: "Noto Sans JP", sans-serif; font-size: 25px; font-weight: 900; }
.kanji-review-header h2 { margin: 3px 0 0; font-size: 22px; }
.kanji-review-header p { margin: 5px 0 0; color: var(--kanji-muted); font-size: 11px; }
.kanji-review-header button { min-height: 42px; padding: 0 14px; border: 1px solid #cfe8d3; border-radius: 12px; color: #267d3c; background: #fff; font-size: 10px; font-weight: 800; cursor: pointer; }
.kanji-review-summary { display: grid; grid-template-columns: auto minmax(80px,1fr) 45px; gap: 15px; align-items: center; padding: 16px 22px; border-bottom: 1px solid #edf0ee; }
.kanji-review-summary span { font-size: 11px; font-weight: 800; }
.kanji-review-summary-track { height: 8px; overflow: hidden; border-radius: 999px; background: #e6e9ec; }
.kanji-review-summary-track i { display: block; width: 0; height: 100%; border-radius: inherit; background: var(--kanji-primary); transition: width .3s ease; }
.kanji-review-table { display: grid; gap: 1px; padding: 16px 18px; background: #edf0ee; }
.kanji-review-group-title { padding: 11px 13px; color: #267d3c; background: #edf9ef; font-size: 10px; font-weight: 900; letter-spacing: .04em; }
.kanji-review-row {
  display: grid;
  grid-template-columns: 38px minmax(0, 1fr) minmax(180px, 240px) 34px;
  gap: 12px;
  align-items: center;
  min-height: 66px;
  padding: 10px 12px;
  background: #fff;
}
.kanji-review-number { display: grid; width: 32px; height: 32px; place-items: center; border-radius: 10px; color: #677080; background: #f3f5f7; font-size: 10px; font-weight: 900; }
.kanji-review-sentence { font-family: "Noto Sans JP", sans-serif; font-size: 13px; line-height: 1.75; }
.kanji-review-input { width: 100%; min-height: 42px; padding: 0 12px; border: 1px solid #d9dfe2; border-radius: 11px; color: var(--kanji-ink); background: #fff; font-family: "Noto Sans JP", sans-serif; font-size: 13px; outline: none; transition: .2s ease; }
.kanji-review-input:focus { border-color: #7edb7a; box-shadow: 0 0 0 3px rgba(79,207,102,.13); }
.kanji-review-row.is-correct .kanji-review-input { border-color: #77d286; background: #f3fcf4; }
.kanji-review-row.is-wrong .kanji-review-input { border-color: #f3a2a2; background: #fff7f7; }
.kanji-review-status { display: grid; width: 30px; height: 30px; place-items: center; border-radius: 50%; color: #a5adb8; background: #f4f6f8; font-size: 14px; font-weight: 900; }
.kanji-review-row.is-correct .kanji-review-status { color: #fff; background: var(--kanji-primary-dark); }
.kanji-review-row.is-wrong .kanji-review-status { color: #fff; background: var(--kanji-red); }
.kanji-review-actions { display: flex; justify-content: center; padding: 4px 18px 24px; }
.kanji-review-reset { display: flex; align-items: center; justify-content: center; gap: 9px; min-width: 180px; min-height: 48px; border: 0; border-radius: 15px; color: #fff; background: linear-gradient(145deg, #6edb78, var(--kanji-primary-dark)); font-size: 12px; font-weight: 800; cursor: pointer; box-shadow: 0 10px 22px rgba(46,169,74,.2); }
.kanji-review-reset svg { width: 19px; height: 19px; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }

.kanji-right-sidebar { display: grid; gap: 15px; }
.kanji-side-card { overflow: hidden; border-radius: 22px; }
.kanji-side-card-title { display: flex; align-items: center; gap: 10px; padding: 17px 18px; border-bottom: 1px solid #edf0f2; }
.kanji-side-card-title svg { width: 21px; height: 21px; fill: none; stroke: var(--kanji-primary-dark); stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }
.kanji-side-card-title h2 { margin: 0; font-size: 13px; }
.kanji-stats-list { padding: 7px 17px 13px; }
.kanji-stats-list > div { display: grid; grid-template-columns: 32px 1fr auto; gap: 8px; align-items: center; min-height: 51px; border-bottom: 1px solid #f0f2f4; }
.kanji-stats-list > div:last-child { border-bottom: 0; }
.kanji-stats-list span:nth-child(2) { color: #697283; font-size: 10px; }
.kanji-stats-list strong { font-size: 14px; }
.kanji-stat-icon { display: grid; width: 27px; height: 27px; place-items: center; border-radius: 50%; font-size: 11px; font-weight: 900; }
.kanji-stat-icon.is-learned { color: #3479da; background: #eaf2ff; }
.kanji-stat-icon.is-remembered { color: #2a9d45; background: #e6f8e9; }
.kanji-stat-icon.is-review { color: #e36a31; background: #fff0e8; }
.kanji-stat-icon.is-accuracy { color: #8653d4; background: #f1eaff; }

.kanji-goal-card { text-align: center; }
.kanji-goal-ring {
  --goal-progress: 0deg;
  position: relative;
  display: grid;
  width: 155px;
  height: 155px;
  place-items: center;
  margin: 24px auto 15px;
  border-radius: 50%;
  background: conic-gradient(var(--kanji-primary) var(--goal-progress), #edf0ef 0);
}
.kanji-goal-ring::before { content: ""; position: absolute; inset: 13px; border-radius: 50%; background: #fff; }
.kanji-goal-ring > div { position: relative; z-index: 1; display: grid; }
.kanji-goal-ring strong { font-size: 24px; }
.kanji-goal-ring span { color: #7a8492; font-size: 10px; }
.kanji-goal-card > p { margin: 0; padding: 0 17px 21px; color: #717b89; font-size: 10px; line-height: 1.6; }

.kanji-tip-bulb { font-size: 20px; }
.kanji-tip-content { display: grid; grid-template-columns: 106px minmax(0,1fr); gap: 10px; align-items: end; padding: 13px 14px 15px; }
.kanji-tip-mascot { position: relative; width: 106px; height: 132px; overflow: hidden; border-radius: 16px; background: #fff9e9; }
.kanji-tip-mascot img { display: block; width: 100%; height: 100%; object-fit: contain; object-position: center bottom; }
.kanji-tip-content p { margin: 0; padding: 11px; border: 1px solid #f0e5c7; border-radius: 13px; color: #6f6653; background: #fffdf7; font-size: 9px; line-height: 1.75; }

.kanji-toast { position: fixed; z-index: 2200; left: 50%; bottom: 28px; transform: translateX(-50%); min-width: 220px; max-width: calc(100% - 32px); padding: 12px 17px; border-radius: 13px; color: #fff; background: rgba(23,32,51,.94); box-shadow: 0 12px 30px rgba(0,0,0,.2); font-size: 11px; font-weight: 700; text-align: center; }

.kanji-page-shell.is-lesson-sidebar-collapsed { grid-template-columns: 76px minmax(0,1fr) 306px; }
.is-lesson-sidebar-collapsed .kanji-left-sidebar { width: 76px; }
.is-lesson-sidebar-collapsed .lesson-sidebar-toggle { right: -13px; }
.is-lesson-sidebar-collapsed .lesson-sidebar-toggle svg { transform: rotate(180deg); }
.is-lesson-sidebar-collapsed .kanji-sidebar-card { padding: 11px 8px; }
.is-lesson-sidebar-collapsed .kanji-sidebar-heading { justify-content: center; padding: 3px 0 11px; }
.is-lesson-sidebar-collapsed .kanji-sidebar-heading > div { display: none; }
.is-lesson-sidebar-collapsed .kanji-sidebar-heading-icon { width: 42px; height: 42px; flex-basis: 42px; }
.is-lesson-sidebar-collapsed .kanji-lesson-group { border-color: transparent; background: transparent; box-shadow: none; }
.is-lesson-sidebar-collapsed .kanji-lesson-parent { display: flex; min-height: 50px; justify-content: center; padding: 5px; border-radius: 13px; }
.is-lesson-sidebar-collapsed .kanji-lesson-parent-number { width: 46px; height: 38px; font-size: 9px; }
.is-lesson-sidebar-collapsed .kanji-lesson-parent-copy,
.is-lesson-sidebar-collapsed .kanji-lesson-chevron { display: none; }
.is-lesson-sidebar-collapsed .kanji-lesson-submenu { gap: 6px; padding: 6px 0 0; border-top: 0; }
.is-lesson-sidebar-collapsed .kanji-lesson-item { display: flex; min-height: 50px; justify-content: center; padding: 6px; }
.is-lesson-sidebar-collapsed .kanji-lesson-number { width: 42px; height: 38px; }
.is-lesson-sidebar-collapsed .kanji-lesson-copy,
.is-lesson-sidebar-collapsed .kanji-lesson-star { display: none; }

html.dark body.n4-kanji-page {
  --kanji-ink: #edf2f7;
  --kanji-muted: #a7b0be;
  --kanji-line: #2c333d;
  --kanji-card: #171b22;
  --kanji-page: #0f1115;
  background: radial-gradient(circle at 11% 7%, rgba(79,207,102,.08), transparent 25%), #0f1115;
}
html.dark .kanji-sidebar-card,
html.dark .kanji-side-card,
html.dark .kanji-workspace,
html.dark .kanji-study-card,
html.dark .kanji-reading-section,
html.dark .kanji-review-section { border-color: #2c333d; background: rgba(23,27,34,.96); }
html.dark .kanji-lesson-group { border-color: #343c47; background: #191e25; }
html.dark .kanji-lesson-group.is-open { border-color: #34583d; }
html.dark .kanji-lesson-parent { color: #edf2f7; }
html.dark .kanji-lesson-parent:hover { background: #1d2b21; }
html.dark .kanji-lesson-submenu { border-top-color: #2d353f; }
html.dark .kanji-lesson-item,
html.dark .kanji-learning-card,
html.dark .kanji-reading-row,
html.dark .kanji-review-row,
html.dark .kanji-review-input { color: #edf2f7; border-color: #353d48; background: #1b2028; }
html.dark .kanji-lesson-item.is-active { background: linear-gradient(135deg,#1d3323,#20392a); }
html.dark .kanji-progress-row,
html.dark .kanji-sidebar-heading,
html.dark .kanji-side-card-title,
html.dark .kanji-section-heading,
html.dark .kanji-review-header,
html.dark .kanji-review-summary { border-color: #2d343e; }
html.dark .kanji-learning-card { background: radial-gradient(circle at 12% 8%, rgba(79,207,102,.08), transparent 27%), #1b2028; }
html.dark .kanji-reading-panel.is-on { background: #192435; border-color: #2b4160; }
html.dark .kanji-reading-panel.is-kun { background: #192a20; border-color: #31533a; }
html.dark .kanji-difficult-toggle,
html.dark .lesson-sidebar-toggle,
html.dark .kanji-review-header button { color: #c9d1db; border-color: #3b444f; background: #202630; }
html.dark .kanji-goal-ring::before { background: #171b22; }
html.dark .kanji-tip-content p { color: #d5c9ae; border-color: #4d4536; background: #25221b; }
html.dark .kanji-review-table { background: #303640; }
html.dark .kanji-review-group-title { color: #9ae6a7; background: #1c3022; }
html.dark .kanji-reading-answer,
html.dark .kanji-review-number,
html.dark .kanji-review-status { color: #b6bfcc; background: #252b34; }

@media (max-width: 1250px) {
  .kanji-page-shell { grid-template-columns: 232px minmax(0,1fr); }
  .kanji-right-sidebar { position: static; grid-column: 1 / -1; grid-template-columns: repeat(3, minmax(0,1fr)); }
  .kanji-page-shell.is-lesson-sidebar-collapsed { grid-template-columns: 76px minmax(0,1fr); }
}

@media (max-width: 900px) {
  .kanji-page-shell,
  .kanji-page-shell.is-lesson-sidebar-collapsed { width: min(100% - 24px, 760px); grid-template-columns: 1fr; }
  .kanji-left-sidebar,
  .kanji-right-sidebar { position: static; width: auto !important; max-height: none; }
  .kanji-lesson-card { max-height: none; overflow: visible; }

  .lesson-sidebar-toggle { display: none; }
  .kanji-right-sidebar { grid-column: auto; grid-template-columns: 1fr 1fr; }
  .kanji-tip-card { grid-column: 1 / -1; }
  .is-lesson-sidebar-collapsed .kanji-sidebar-heading > div,
  .is-lesson-sidebar-collapsed .kanji-lesson-parent-copy,
  .is-lesson-sidebar-collapsed .kanji-lesson-copy,
  .is-lesson-sidebar-collapsed .kanji-lesson-star { display: initial; }
  .is-lesson-sidebar-collapsed .kanji-lesson-parent { display: grid; grid-template-columns: 48px minmax(0,1fr) 20px; justify-content: initial; padding: 9px 11px; }
  .is-lesson-sidebar-collapsed .kanji-lesson-chevron { display: block; }
  .is-lesson-sidebar-collapsed .kanji-lesson-submenu { padding: 8px 8px 9px 22px; border-top: 1px solid #edf1ee; }
  .is-lesson-sidebar-collapsed .kanji-lesson-item { display: grid; justify-content: initial; }
}

@media (max-width: 660px) {
  .kanji-page-shell { width: calc(100% - 16px); padding-top: 14px; }
  .kanji-workspace { padding: 15px; border-radius: 19px; }
  .kanji-page-heading { align-items: flex-start; }
  .kanji-level-badge { width: 50px; height: 50px; flex-basis: 50px; border-radius: 16px; font-size: 16px; }
  .kanji-page-heading h1 { font-size: 23px; }
  .kanji-progress-row { grid-template-columns: 1fr auto; gap: 8px; padding: 13px 16px; }
  .kanji-progress-track { grid-column: 1 / -1; grid-row: 2; }
  .kanji-card-stage { padding: 20px 13px 15px; }
  .kanji-learning-card { min-height: 430px; padding: 19px 18px 25px; border-radius: 22px; }
  .kanji-character { font-size: 112px; }
  .kanji-reading-grid { grid-template-columns: 1fr; }
  .kanji-primary-actions { grid-template-columns: 1fr; padding: 0 13px 20px; }
  .kanji-section-heading { align-items: flex-start; }
  .kanji-reading-hint { display: none; }
  .kanji-reading-row { grid-template-columns: 30px minmax(0,1fr); }
  .kanji-reading-answer { grid-column: 2; min-width: 0; }
  .kanji-review-header { align-items: flex-start; flex-direction: column; }
  .kanji-review-row { grid-template-columns: 32px minmax(0,1fr) 30px; }
  .kanji-review-input { grid-column: 2 / 3; }
  .kanji-review-status { grid-column: 3; grid-row: 1 / 3; }
  .kanji-right-sidebar { grid-template-columns: 1fr; }
  .kanji-tip-card { grid-column: auto; }
}


/* Bài test tổng hợp được đặt giữa Bài 4 và Bài 5. */
.kanji-summary-test-link {
  display: grid;
  grid-template-columns: 46px minmax(0, 1fr) 20px;
  gap: 10px;
  align-items: center;
  min-height: 64px;
  padding: 9px 11px;
  border: 1px solid #b9e6bf;
  border-radius: 17px;
  color: var(--kanji-ink);
  background: linear-gradient(135deg, #f4fff5, #e8f9eb);
  text-decoration: none;
  box-shadow: 0 8px 18px rgba(46,169,74,.08);
  transition: transform .2s ease, border-color .2s ease, box-shadow .2s ease;
}
.kanji-summary-test-link:hover { transform: translateY(-1px); border-color: #83d890; box-shadow: 0 11px 23px rgba(46,169,74,.14); }
.kanji-summary-test-link.is-active { border-color: var(--kanji-primary); background: linear-gradient(135deg, #e7f9ea, #d9f3de); }
.kanji-summary-test-icon { display: grid; width: 44px; height: 42px; place-items: center; border-radius: 12px; color: #fff; background: linear-gradient(145deg, #54c968, #269e42); font-family: "Noto Sans JP", sans-serif; font-size: 17px; font-weight: 900; }
.kanji-summary-test-copy { min-width: 0; }
.kanji-summary-test-copy strong { display: block; font-size: 12px; }
.kanji-summary-test-copy small { display: block; overflow: hidden; margin-top: 3px; color: #74817a; font-size: 9px; font-weight: 600; text-overflow: ellipsis; white-space: nowrap; }
.kanji-summary-test-link > svg { width: 19px; height: 19px; fill: none; stroke: #4e7f59; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }
.is-lesson-sidebar-collapsed .kanji-summary-test-link { display: flex; min-height: 50px; justify-content: center; padding: 5px; }
.is-lesson-sidebar-collapsed .kanji-summary-test-icon { width: 46px; height: 38px; font-size: 14px; }
.is-lesson-sidebar-collapsed .kanji-summary-test-copy,
.is-lesson-sidebar-collapsed .kanji-summary-test-link > svg { display: none; }
html.dark .kanji-summary-test-link { color: #edf2f7; border-color: #34583d; background: linear-gradient(135deg,#1d3323,#20392a); }
html.dark .kanji-summary-test-copy small { color: #9fb0a3; }
@media (max-width: 900px) {
  .is-lesson-sidebar-collapsed .kanji-summary-test-link { display: grid; grid-template-columns: 46px minmax(0, 1fr) 20px; justify-content: initial; padding: 9px 11px; }
  .is-lesson-sidebar-collapsed .kanji-summary-test-copy,
  .is-lesson-sidebar-collapsed .kanji-summary-test-link > svg { display: initial; }
}