:root {
  --bg: #f7f8fc;
  --surface: #ffffff;
  --surface-soft: #f1f5f9;
  --ink: #111827;
  --muted: #667085;
  --line: #e6e9f2;
  --primary: #5546e8;
  --primary-dark: #3525bd;
  --success: #099268;
  --success-soft: #ddfbe8;
  --warning: #f5a524;
  --warning-soft: #fff4d6;
  --danger: #e5484d;
  --danger-soft: #ffe5e8;
  --cyan: #0ea5b7;
  --pink: #d9468b;
  --navy: #070b24;
  --shadow: 0 12px 32px rgba(15, 23, 42, 0.08);
  --radius: 8px;
  --container: 1180px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 12px;
  line-height: 1.5;
}

body.viewer-locked {
  user-select: none;
  -webkit-user-select: none;
}

button,
input,
select,
textarea {
  font: inherit;
}

button {
  cursor: pointer;
}

a {
  color: inherit;
  text-decoration: none;
}

.boot-screen {
  min-height: 100vh;
  display: grid;
  place-items: center;
  align-content: center;
  gap: 14px;
  color: var(--muted);
}

.brand-mark {
  width: 48px;
  height: 48px;
  display: grid;
  place-items: center;
  color: #492d8f;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 50%;
  font-weight: 800;
  letter-spacing: 0;
  box-shadow: var(--shadow);
}

.brand-logo {
  width: 54px;
  height: 54px;
  display: block;
  object-fit: contain;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
  flex: 0 0 auto;
}

.boot-logo {
  width: 118px;
  height: 118px;
  border-radius: 14px;
}

.page-shell {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(247, 248, 252, 0.92);
  border-bottom: 1px solid rgba(230, 233, 242, 0.72);
  backdrop-filter: blur(18px);
}

.topbar-inner {
  width: min(var(--container), calc(100% - 28px));
  height: 72px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 18px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-width: 145px;
}

.header-brand {
  width: 54px;
  min-width: 54px;
  flex: 0 0 54px;
}

.brand-name {
  display: grid;
  line-height: 1.05;
}

.brand-name strong {
  font-size: 16px;
}

.brand-name span {
  color: var(--muted);
  font-size: 12px;
}

.nav-pills {
  display: flex;
  justify-content: center;
  gap: 6px;
  min-width: 0;
}

.nav-pills a {
  min-height: 34px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 14px;
  border: 1px solid rgba(203, 213, 225, 0.72);
  border-radius: 999px;
  color: #344054;
  background: #eef2f7;
  font-size: 13px;
  white-space: nowrap;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.7);
  transition: background 0.16s ease, border-color 0.16s ease, color 0.16s ease, box-shadow 0.16s ease;
}

.admin-topbar .nav-pills {
  gap: 0;
}

.announcement-ticker {
  position: relative;
  z-index: 12;
  width: 100%;
  overflow: hidden;
  border-bottom: 1px solid rgba(230, 233, 242, 0.92);
  background: linear-gradient(90deg, #fff7ed, #eef7ff 48%, #f4f0ff);
  color: #172033;
}

.announcement-track {
  display: inline-flex;
  width: max-content;
  min-width: 100%;
  gap: 34px;
  padding: 8px 0;
  white-space: nowrap;
  animation: announcement-scroll 32s linear infinite;
}

.announcement-line {
  display: inline-flex;
  align-items: center;
  gap: 20px;
  padding-left: 34px;
  font-size: 14px;
  font-weight: 700;
}

.announcement-line a {
  color: inherit;
  text-decoration: none;
  max-width: 680px;
  overflow: hidden;
  text-overflow: ellipsis;
}

.announcement-line a:hover {
  color: var(--primary-dark);
}

.announcement-line strong {
  color: var(--primary);
}

.announcement-line i {
  color: #f59e0b;
  font-style: normal;
}

.announcement-ticker:hover .announcement-track {
  animation-play-state: paused;
}

@keyframes announcement-scroll {
  from {
    transform: translateX(0);
  }
  to {
    transform: translateX(-50%);
  }
}

@media (prefers-reduced-motion: reduce) {
  .announcement-track {
    animation: none;
    width: 100%;
    overflow-x: auto;
  }
}

.nav-pills a:hover {
  background: #e2e8f0;
  border-color: #cbd5e1;
  color: #172033;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.78), 0 8px 18px rgba(15, 23, 42, 0.06);
}

.nav-pills a.active {
  background: var(--primary);
  border-color: var(--primary);
  color: #fff;
  font-weight: 800;
  box-shadow: 0 10px 22px rgba(85, 70, 232, 0.24);
}

.top-actions {
  display: inline-flex;
  align-items: center;
  justify-content: flex-end;
  gap: 10px;
}

.container {
  width: min(var(--container), calc(100% - 28px));
  margin: 0 auto;
}

.main {
  flex: 1;
}

.section {
  padding: 44px 0;
}

.section.tight {
  padding: 28px 0;
}

.eyebrow {
  color: var(--primary);
  font-size: 12px;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.page-title {
  margin: 0 0 8px;
  color: var(--ink);
  font-size: 34px;
  line-height: 1.08;
}

.page-title .accent,
.hero-title .accent {
  color: var(--primary);
}

.page-subtitle {
  margin: 0;
  color: var(--muted);
  max-width: 680px;
}

.toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  margin: 24px 0;
}

.toolbar.wrap {
  flex-wrap: wrap;
}

.toolbar-left,
.toolbar-right,
.actions {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.hero {
  background: radial-gradient(circle at 82% 20%, rgba(85, 70, 232, 0.28), transparent 26%),
    linear-gradient(135deg, #070b24 0%, #0d1638 56%, #06111f 100%);
  color: #fff;
}

.home-hero {
  position: relative;
  overflow: hidden;
  isolation: isolate;
  background: #07111f;
}

.hero-interactive-canvas {
  position: absolute;
  inset: 0;
  z-index: 0;
  width: 100%;
  height: 100%;
  display: block;
  pointer-events: none;
}

.home-hero .hero-grid {
  position: relative;
  z-index: 1;
}

.compact-hero .section {
  padding: 26px 0;
}

.compact-hero .page-title {
  margin-bottom: 6px;
  font-size: 30px;
}

.compact-hero .page-subtitle {
  margin-bottom: 0;
  font-size: 15px;
}

.compact-hero .pill {
  padding: 8px 14px;
}

.compact-hero + .section {
  padding-top: 18px;
}

.hero-grid {
  width: min(var(--container), calc(100% - 28px));
  min-height: 510px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(360px, 0.86fr);
  gap: 40px;
  align-items: center;
  padding: 46px 0 42px;
}

.hero-title {
  margin: 12px 0 16px;
  max-width: 640px;
  font-size: 54px;
  line-height: 1.02;
  letter-spacing: 0;
}

.hero-copy {
  max-width: 570px;
  color: #d7deef;
  font-size: 16px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.hero-media {
  position: relative;
  min-height: 318px;
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: var(--radius);
  overflow: hidden;
  display: grid;
  place-items: center;
  background: linear-gradient(160deg, rgba(238, 242, 255, 0.96) 0%, rgba(248, 250, 255, 0.98) 100%);
  box-shadow: 0 30px 80px rgba(0, 0, 0, 0.36);
}

.hero-media::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.02), rgba(13, 22, 56, 0.08));
  pointer-events: none;
}

.hero-media-image {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  z-index: 1;
}

.hero-media-frame {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: 0;
  background: #fff;
  z-index: 1;
}

.site-media-preview {
  min-height: 220px;
  border: 1px solid var(--line);
  border-radius: 14px;
  overflow: hidden;
  display: grid;
  place-items: center;
  background: #f8fafc;
}

.site-media-preview img,
.site-media-preview iframe {
  width: 100%;
  height: 100%;
  min-height: 220px;
  border: 0;
  object-fit: contain;
  background: #fff;
}

.hero-chip {
  position: absolute;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 34px;
  padding: 0 12px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.92);
  color: #1d2939;
  font-size: 12px;
  font-weight: 700;
  z-index: 2;
}

.hero-chip.one {
  top: 28px;
  left: 24px;
}

.hero-chip.two {
  right: 20px;
  bottom: 54px;
}

.stats-band {
  margin-top: -24px;
}

.stat-strip {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--line);
  box-shadow: var(--shadow);
}

.stat-item {
  padding: 22px;
  background: #fff;
  text-align: center;
}

.stat-item strong {
  display: block;
  font-size: 24px;
}

.stat-item span {
  color: var(--muted);
  font-size: 12px;
}

.feature-grid,
.book-grid,
.admin-grid,
.class-grid,
.group-grid {
  display: grid;
  gap: 18px;
}

.feature-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.book-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.admin-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.class-grid,
.group-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.blog-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.blog-grid.admin {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.blog-grid.compact {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.category-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.registration-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(320px, 0.85fr);
  gap: 18px;
  align-items: start;
}

.recommended-band {
  margin: 10px 0 24px;
  padding: 18px;
  border: 1px solid #d8ddff;
  border-radius: var(--radius);
  background: #f7f8ff;
}

.book-grid.compact {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.cart-list {
  display: grid;
  gap: 14px;
}

.cart-row {
  display: grid;
  grid-template-columns: 128px minmax(0, 1fr) auto;
  gap: 16px;
  align-items: center;
  padding: 14px;
}

.cart-row .book-cover {
  height: 104px;
  border-radius: var(--radius);
}

.cart-row h3 {
  margin: 4px 0 6px;
}

.cart-summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-top: 16px;
}

.categories-section {
  background: #ffffff;
}

.category-card {
  display: grid;
  grid-template-columns: 78px 1fr;
  gap: 14px;
  padding: 16px;
  align-items: start;
}

.category-card.active {
  border-color: #5546e8;
  box-shadow: 0 0 0 3px rgba(85, 70, 232, 0.12), var(--shadow);
}

.category-visual {
  width: 78px;
  height: 78px;
  display: grid;
  place-items: center;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #eef7ff;
  color: #1f3d8a;
  font-weight: 900;
  overflow: hidden;
}

.category-visual img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.category-card h3 {
  margin: 0 0 6px;
  font-size: 17px;
}

.category-card p {
  margin: 0 0 12px;
  color: var(--muted);
  font-size: 13px;
}

.category-chip-list {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
}

.category-chip {
  min-height: 32px;
  padding: 6px 10px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: #fff;
  color: #344054;
  font-size: 12px;
  font-weight: 800;
}

.category-chip:hover {
  border-color: #5546e8;
  color: #3525bd;
}

.category-flow {
  margin: 12px 0 18px;
  padding: 12px 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #f8fbff;
  color: #344054;
  font-size: 13px;
  font-weight: 800;
}

.admin-category-panel {
  margin: 18px 0 24px;
  padding: 16px;
}

.category-table {
  margin-top: 12px;
  min-width: 920px;
}

.data-table.compact th,
.data-table.compact td {
  padding: 11px 12px;
}

.module-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.module-list {
  display: grid;
  gap: 14px;
}

.admin-test-row-list {
  display: grid;
  gap: 12px;
}

.module-card {
  display: grid;
  grid-template-columns: 68px 1fr;
  gap: 14px;
  padding: 16px;
  align-items: start;
}

.admin-test-card {
  grid-template-columns: 1fr;
  align-items: center;
  padding: 18px 22px;
}

.admin-test-content {
  min-width: 0;
}

.admin-test-content .book-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.admin-test-content .actions {
  margin-top: 10px;
}

.module-card h3,
.test-card h3,
.plan-card h3,
.certificate-card h3,
.formula-card h3 {
  margin: 0 0 6px;
}

.module-icon {
  width: 68px;
  height: 68px;
  display: grid;
  place-items: center;
  border-radius: var(--radius);
  background: #eef7ff;
  color: #1f3d8a;
  font-weight: 900;
  text-align: center;
}

.test-card {
  padding: 18px;
}

.test-list-layout {
  display: grid;
  gap: 16px;
}

.test-row-list {
  gap: 10px;
}

.test-row-card {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 14px 16px;
  cursor: pointer;
  transition: border-color 0.2s ease, box-shadow 0.2s ease, transform 0.2s ease;
}

.test-row-card:hover,
.test-row-card.selected {
  border-color: #c9c4ff;
  box-shadow: 0 14px 34px rgba(85, 70, 232, 0.12);
  transform: translateY(-1px);
}

.test-row-card h3 {
  margin-bottom: 4px;
}

.test-row-meta {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.selected-test-panel {
  display: grid;
}

.selected-test-panel.focused {
  max-width: 100%;
}

.math-content {
  max-width: 100%;
  overflow-x: auto;
  overflow-y: hidden;
  line-height: 1.65;
  overflow-wrap: anywhere;
}

.math-content p {
  margin: 0 0 8px;
}

.math-content img,
.math-content svg,
.math-content canvas,
.math-content video {
  max-width: 100%;
  height: auto;
}

.math-content mjx-container,
.math-content .MathJax,
.math-preview-panel mjx-container,
.quiz-question mjx-container,
.answer-key-card mjx-container {
  max-width: 100%;
  overflow-x: auto;
  overflow-y: hidden;
}

.latex-rendered {
  display: grid;
  gap: 6px;
  max-width: 100%;
  overflow-x: auto;
  padding-bottom: 2px;
  color: var(--primary-dark);
  font-family: Cambria Math, STIX Two Math, Times New Roman, serif;
  font-size: clamp(1.05rem, 1rem + 0.25vw, 1.34rem);
  font-weight: 700;
  line-height: 1.7;
  white-space: nowrap;
}

.latex-line {
  min-width: max-content;
}

.latex-frac {
  display: inline-grid;
  grid-template-rows: auto auto;
  align-items: center;
  justify-items: center;
  min-width: 1.35em;
  margin: 0 0.16em;
  vertical-align: middle;
  line-height: 1.05;
}

.latex-frac > span:first-child {
  width: 100%;
  padding: 0 0.18em 0.12em;
  border-bottom: 1.8px solid currentColor;
  text-align: center;
}

.latex-frac > span:last-child {
  padding: 0.12em 0.18em 0;
  text-align: center;
}

.latex-root {
  display: inline-flex;
  align-items: flex-start;
  gap: 0.04em;
}

.latex-root > span {
  border-top: 1.6px solid currentColor;
  padding: 0.02em 0.12em 0;
}

.latex-rendered sup,
.latex-rendered sub {
  font-size: 0.72em;
  line-height: 0;
}

.question-text {
  color: var(--ink);
  font-size: 1.18rem;
  font-weight: 800;
}

.test-start-panel {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  margin-top: 16px;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fbfcff;
}

.test-start-panel strong {
  color: var(--ink);
}

.test-detail-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(120px, 1fr));
  gap: 10px;
  margin-top: 14px;
}

.test-detail-grid span {
  display: grid;
  gap: 4px;
  padding: 10px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #fff;
  color: var(--muted);
  font-size: 0.92rem;
}

.test-detail-grid strong {
  color: var(--ink);
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.02em;
}

.test-instruction-panel {
  display: grid;
  gap: 14px;
  margin-top: 16px;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fbfcff;
}

.test-instruction-panel h4 {
  margin: 4px 0 8px;
  color: var(--ink);
  font-size: 1.25rem;
}

.instruction-list {
  margin: 10px 0 0;
  padding-left: 20px;
  color: var(--muted);
}

.declaration-check {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px;
  border: 1px solid #c9c4ff;
  border-radius: var(--radius);
  background: #f7f6ff;
  color: var(--ink);
  font-weight: 800;
}

.test-status-cluster {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.test-security-notice {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
  margin-top: 14px;
  padding: 12px;
  border: 1px solid #c9c4ff;
  border-radius: var(--radius);
  background: #f7f6ff;
  color: #344054;
}

.test-security-notice strong {
  color: var(--primary-dark);
}

.question-jump-row {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.question-jump {
  width: 38px;
  height: 38px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #fff;
  color: var(--ink);
  font-weight: 900;
  cursor: pointer;
}

.question-jump.active {
  background: var(--primary);
  border-color: var(--primary);
  color: #fff;
}

.question-jump.answered:not(.active) {
  background: #eafaf1;
  border-color: #b7efd0;
  color: #057a48;
}

.question-jump.visited:not(.active) {
  background: #fff7ed;
  border-color: #fed7aa;
  color: #b45309;
}

.question-jump.review:not(.active) {
  background: #faf5ff;
  border-color: #d8b4fe;
  color: #7e22ce;
}

.question-jump.answered-review:not(.active) {
  background: #eef2ff;
  border-color: #a5b4fc;
  color: #3730a3;
}

.question-legend {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  align-items: center;
  color: var(--muted);
  font-size: 0.9rem;
}

.question-legend span {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.legend-box {
  width: 14px;
  height: 14px;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: #fff;
}

.legend-box.visited {
  background: #fff7ed;
  border-color: #fed7aa;
}

.legend-box.answered {
  background: #eafaf1;
  border-color: #b7efd0;
}

.legend-box.review {
  background: #faf5ff;
  border-color: #d8b4fe;
}

.legend-box.answered-review {
  background: #eef2ff;
  border-color: #a5b4fc;
}

.quiz-form {
  display: grid;
  gap: 14px;
  margin-top: 14px;
}

.quiz-question {
  padding: 18px;
  border: 1px solid #d9dcff;
  border-radius: var(--radius);
  background: linear-gradient(180deg, #ffffff, #fbfcff);
  box-shadow: 0 12px 30px rgba(15, 23, 42, 0.05);
}

.quiz-options {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px;
  margin: 10px 0;
}

.quiz-options label {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 9px 10px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
  cursor: pointer;
}

.quiz-options input {
  margin-top: 5px;
}

.option-label {
  flex: 0 0 auto;
  color: var(--primary-dark);
  font-weight: 900;
}

.option-math {
  flex: 1 1 auto;
  min-width: 0;
}

.quiz-options label.selected {
  border-color: var(--primary);
  background: #f1f0ff;
  color: var(--primary-dark);
  font-weight: 900;
}

.question-head {
  display: grid;
  gap: 10px;
}

.question-image {
  max-width: min(100%, 680px);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.formula-chip {
  width: fit-content;
  max-width: 100%;
  padding: 8px 10px;
  border: 1px solid #c9c4ff;
  border-radius: 10px;
  background: #f7f6ff;
  color: var(--primary-dark);
  font-weight: 800;
  overflow-wrap: anywhere;
}

.math-editor-toolbar {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin: 8px 0 10px;
}

.math-editor-toolbar .btn {
  min-height: 38px;
  padding: 7px 12px;
}

.math-preview-panel {
  margin-top: 12px;
  padding: 14px;
  border: 1px solid #d9dcff;
  border-radius: var(--radius);
  background: #fbfcff;
}

.math-preview-question {
  display: grid;
  gap: 10px;
}

.math-preview-question > strong {
  color: var(--ink);
}

.preview-options {
  margin: 0;
}

.math-question-builder {
  display: grid;
  gap: 14px;
}

.question-builder-list {
  display: grid;
  gap: 16px;
}

.question-builder-card {
  display: grid;
  gap: 14px;
  padding: 16px;
  border: 1px solid #d9dcff;
  border-radius: var(--radius);
  background: #fbfcff;
}

.question-builder-card h4 {
  margin: 0;
  color: var(--ink);
}

.question-builder-part {
  display: grid;
  gap: 8px;
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: #fff;
}

.question-builder-part-row {
  display: grid;
  grid-template-columns: 100px 112px minmax(220px, 1fr) 190px;
  align-items: center;
  gap: 10px;
}

.question-builder-part-row label {
  margin: 0;
  color: var(--ink);
  font-weight: 900;
}

.compact-select {
  width: 100%;
  min-height: 40px;
  padding: 8px 10px;
}

.question-builder-part-row textarea {
  min-height: 52px;
  resize: vertical;
}

.compact-file-input {
  min-height: 52px;
  padding: 10px;
}

.math-editor-toolbar.compact {
  margin: 0;
}

.math-editor-toolbar.compact .btn {
  min-height: 32px;
  padding: 5px 9px;
  font-size: 0.86rem;
}

.question-part-preview {
  min-height: 58px;
  padding: 10px;
  border: 1px dashed #c9c4ff;
  border-radius: 10px;
  background: #f7f6ff;
}

.question-option-builder-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.legacy-question-format {
  padding: 12px;
  border: 1px dashed var(--line);
  border-radius: var(--radius);
  background: #fff;
}

.legacy-question-format summary {
  cursor: pointer;
  color: var(--primary-dark);
  font-weight: 900;
}

.test-nav-actions {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.test-locked {
  user-select: none;
}

.test-submit-summary {
  display: grid;
  gap: 12px;
}

.test-focus-banner,
.solution-locked {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
  margin-bottom: 16px;
  padding: 12px 14px;
  border: 1px solid #fed7aa;
  border-radius: var(--radius);
  background: #fff7ed;
  color: #9a3412;
}

.test-focus-banner strong,
.solution-locked strong {
  color: #7c2d12;
}

.solution-locked {
  display: grid;
  align-items: start;
  margin: 12px 0 0;
}

.solution-locked p {
  margin: 0;
}

.test-result-view {
  display: grid;
  gap: 16px;
}

.answer-key-title {
  margin: 4px 0 0;
  color: var(--ink);
}

.answer-key-list {
  display: grid;
  gap: 12px;
  max-height: min(58vh, 620px);
  overflow: auto;
  padding-right: 4px;
}

.test-result-modal {
  width: min(1180px, calc(100vw - 24px));
}

.test-result-body {
  flex: 1 1 auto;
  min-height: 0;
}

.test-result-modal.test-result-maximized {
  width: calc(100vw - 16px);
  height: calc(100vh - 16px);
  max-height: none;
  border-radius: 12px;
}

.test-result-modal.test-result-maximized .test-result-body,
.test-result-modal:fullscreen .test-result-body {
  overflow: auto;
}

.test-result-modal.test-result-maximized .answer-key-list,
.test-result-modal:fullscreen .answer-key-list {
  max-height: none;
  overflow: visible;
}

.test-result-modal:fullscreen {
  width: 100vw;
  height: 100vh;
  max-height: none;
  border-radius: 0;
}

.test-result-modal:fullscreen .modal-header,
.test-result-modal:fullscreen .modal-footer {
  flex: 0 0 auto;
}

.answer-key-card {
  display: grid;
  gap: 10px;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
}

.answer-key-card.correct {
  border-color: #b7efd0;
}

.answer-key-card.wrong {
  border-color: #fecaca;
}

.answer-key-head {
  display: flex;
  gap: 10px;
  align-items: flex-start;
}

.answer-comparison {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 8px;
}

.answer-comparison span {
  display: grid;
  gap: 3px;
  padding: 9px;
  border-radius: 10px;
  background: #f8fafc;
  color: var(--muted);
}

.answer-comparison strong,
.solution-box strong {
  color: var(--ink);
}

.solution-box {
  padding: 10px;
  border-radius: 10px;
  background: #f7f6ff;
  color: #344054;
}

.solution-box p {
  margin: 6px 0 0;
}

.solution-box.muted {
  background: #f8fafc;
  color: var(--muted);
}

.progress-bar {
  height: 10px;
  margin: 10px 0 14px;
  overflow: hidden;
  border-radius: 999px;
  background: #e9edf7;
}

.progress-bar span {
  display: block;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, #0ea5b7, #5546e8);
}

.lms-two-col {
  display: grid;
  grid-template-columns: minmax(320px, 0.9fr) minmax(0, 1.1fr);
  gap: 18px;
  align-items: start;
}

.plan-grid {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 16px;
}

.plan-card,
.certificate-card,
.formula-card {
  padding: 18px;
}

.plan-card ul {
  margin: 12px 0;
  padding-left: 18px;
  color: var(--muted);
}

.formula-card code {
  display: block;
  margin: 10px 0;
  padding: 12px;
  border-radius: var(--radius);
  background: #f8fbff;
  color: var(--primary-dark);
  font-weight: 900;
  white-space: normal;
}

.formula-card .toolbar.compact {
  align-items: center;
  gap: 10px;
}

.formula-display,
.formula-example {
  margin: 12px 0;
  padding: 14px;
  border-radius: var(--radius);
  background: #f8fbff;
  border: 1px solid #e3e9f6;
}

.formula-display {
  color: var(--primary-dark);
  font-weight: 900;
  overflow-x: auto;
}

.formula-example {
  background: #fbfbff;
  color: var(--muted);
}

.formula-example strong {
  display: block;
  color: var(--text);
  margin-bottom: 8px;
}

.formula-display img,
.formula-example img,
.formula-live-preview img {
  max-width: 100%;
  height: auto;
}

.formula-editor-block {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 14px;
  background: #fbfcff;
}

.formula-part-row {
  display: grid;
  grid-template-columns: 180px 180px minmax(280px, 1fr) minmax(220px, 0.6fr);
  gap: 12px;
  align-items: start;
}

.formula-live-preview {
  margin-top: 12px;
  min-height: 72px;
  padding: 12px;
  border-radius: var(--radius);
  border: 1px dashed #c9cef8;
  background: white;
  overflow-x: auto;
}

.free-resource-list {
  display: grid;
  gap: 12px;
  margin-top: 16px;
}

.free-resource-list > .card {
  box-shadow: 0 8px 22px rgba(15, 23, 42, 0.04);
}

.free-resource-list .module-card {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
  align-items: center;
  min-height: 116px;
  padding: 16px 18px;
}

.free-resource-list .module-icon {
  display: none;
}

.free-resource-list .book-meta {
  align-items: center;
  justify-content: flex-start;
  gap: 10px;
  margin-bottom: 6px;
}

.free-resource-list .module-card h3,
.free-resource-list .formula-card h3 {
  margin: 0 0 4px;
  font-size: 1.08rem;
}

.free-resource-list .module-card p {
  max-width: 760px;
  margin-bottom: 8px;
}

.free-resource-list .actions {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.free-resource-list .formula-card {
  display: grid;
  grid-template-columns: minmax(220px, 0.55fr) minmax(260px, 1fr) auto;
  gap: 16px;
  align-items: center;
  padding: 16px 18px;
}

.free-resource-list .formula-card .toolbar.compact {
  display: grid;
  gap: 6px;
}

.free-resource-list .formula-display {
  margin: 0;
  min-width: 0;
}

.free-resource-list .formula-example,
.free-resource-list .formula-card p {
  grid-column: 2 / -1;
  margin: 0;
}

.free-resource-list .formula-card .actions {
  justify-content: flex-end;
}

.formula-sheet-row {
  display: grid;
  align-content: start;
  gap: 28px;
  min-height: 150px;
  padding: 26px 28px;
  cursor: pointer;
}

.formula-sheet-row:hover {
  border-color: #c9c4ff;
  box-shadow: 0 12px 28px rgba(85, 70, 232, 0.09);
}

.formula-sheet-row-main {
  display: grid;
  min-width: 0;
}

.formula-sheet-row-main h3 {
  margin: 0;
  color: var(--ink);
  font-size: 1rem;
}

.formula-sheet-row-main p {
  max-width: 760px;
  margin: 0;
}

.formula-sheet-row .actions {
  flex: 0 0 auto;
  justify-content: flex-start;
}

.formula-sheet-detail {
  display: grid;
  gap: 18px;
}

.formula-sheet-title {
  display: grid;
  gap: 8px;
}

.formula-sheet-detail h2 {
  margin: 8px 0 0;
  color: var(--ink);
}

.formula-sheet-panel {
  display: grid;
  gap: 14px;
  padding: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
  overflow: hidden;
}

.formula-sheet-panel .math-content {
  padding: 22px 24px;
}

.formula-file-frame {
  width: 100%;
  min-height: 480px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
}

.formula-html-frame {
  min-height: 560px;
}

.protected-inline-preview,
.protected-inline-card {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #f8fafc;
}

.protected-inline-preview {
  justify-content: flex-start;
  flex-wrap: wrap;
}

.protected-inline-card strong,
.protected-inline-preview strong {
  display: block;
  color: var(--ink);
}

.protected-inline-card span,
.protected-inline-preview span {
  display: block;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.5;
}

.formula-sheet-panel p {
  margin: 0;
}

.formula-sheet-modal .modal-body {
  position: relative;
}

.formula-sheet-modal:fullscreen {
  width: 100vw;
  height: 100vh;
  max-height: none;
  border-radius: 0;
}

.formula-sheet-modal:fullscreen .modal-body {
  overflow: auto;
}

.formula-sheet-modal:fullscreen .formula-sheet-detail {
  min-height: 100%;
  align-content: start;
  padding: 8px;
}

.formula-sheet-modal:fullscreen .formula-sheet-panel {
  padding: 24px;
}

.formula-sheet-modal:fullscreen .latex-rendered {
  font-size: clamp(1.45rem, 1rem + 1.4vw, 2.4rem);
}

@media (max-width: 900px) {
  .formula-part-row {
    grid-template-columns: 1fr;
  }

  .free-resource-list .module-card,
  .free-resource-list .formula-card {
    grid-template-columns: 1fr;
    align-items: start;
  }

  .free-resource-list .formula-example,
  .free-resource-list .formula-card p {
    grid-column: auto;
  }

  .free-resource-list .formula-card .actions {
    justify-content: flex-start;
  }

  .formula-sheet-row {
    gap: 22px;
    min-height: 132px;
    padding: 22px;
  }

  .formula-sheet-row .actions {
    justify-content: flex-start;
  }
}

.admin-grid.two {
  grid-template-columns: minmax(0, 1fr) 430px;
  align-items: start;
}

.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: 0 10px 28px rgba(15, 23, 42, 0.05);
}

.card-pad {
  padding: 20px;
}

.feature-card {
  padding: 20px;
  min-height: 170px;
}

.feature-card h3,
.card h3,
.class-card h3,
.group-card h3 {
  margin: 12px 0 6px;
  font-size: 17px;
}

.feature-card p,
.card p,
.class-card p,
.group-card p {
  color: var(--muted);
  margin: 0;
}

.icon-box {
  width: 38px;
  height: 38px;
  display: inline-grid;
  place-items: center;
  border-radius: var(--radius);
  font-weight: 800;
}

.icon-blue {
  background: #e8efff;
  color: #335cff;
}

.icon-green {
  background: #e5fbef;
  color: var(--success);
}

.icon-pink {
  background: #ffedf5;
  color: var(--pink);
}

.icon-yellow {
  background: var(--warning-soft);
  color: #b76a00;
}

.btn {
  min-height: 38px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 0 16px;
  border: 1px solid transparent;
  border-radius: 999px;
  background: #fff;
  color: var(--ink);
  font-weight: 800;
  font-size: 13px;
  white-space: nowrap;
  transition: transform 0.18s ease, box-shadow 0.18s ease, border-color 0.18s ease;
}

.btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 10px 22px rgba(15, 23, 42, 0.09);
}

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

.btn-primary:hover {
  background: var(--primary-dark);
}

.btn-outline {
  border-color: #c9c8e9;
  color: var(--primary-dark);
}

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

.btn-success {
  background: var(--success);
  color: #fff;
}

.btn-dark {
  background: #101828;
  color: #fff;
}

.icon-btn {
  width: 38px;
  min-width: 38px;
  height: 38px;
  padding: 0;
}

.pill,
.tab {
  min-height: 30px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 12px;
  border: 1px solid #c9c8e9;
  border-radius: 999px;
  background: #fff;
  color: #4b4a72;
  font-size: 12px;
  font-weight: 800;
}

.pill.success {
  background: var(--success-soft);
  border-color: transparent;
  color: var(--success);
}

.pill.warning {
  background: var(--warning-soft);
  border-color: transparent;
  color: #9b5b00;
}

.pill.danger {
  background: var(--danger-soft);
  border-color: transparent;
  color: var(--danger);
}

.tab.active {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

.tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 22px 0;
}

.input,
.select,
.textarea {
  width: 100%;
  min-height: 44px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
  color: var(--ink);
  padding: 0 14px;
  outline: none;
}

.textarea {
  min-height: 92px;
  padding-top: 12px;
  resize: vertical;
}

.input:focus,
.select:focus,
.textarea:focus {
  border-color: #a9a4ff;
  box-shadow: 0 0 0 4px rgba(85, 70, 232, 0.12);
}

.search-row {
  display: grid;
  grid-template-columns: 1fr 220px 220px 190px;
  gap: 12px;
  align-items: end;
  margin: 24px 0;
}

.input-with-button {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 8px;
  align-items: center;
}

.input-with-button .btn {
  min-height: 44px;
  white-space: nowrap;
  border-radius: var(--radius);
}

.field label {
  display: block;
  margin: 0 0 7px;
  color: #344054;
  font-size: 12px;
  font-weight: 800;
}

.form-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.form-grid .span-2 {
  grid-column: 1 / -1;
}

.toggle-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}

.check-row {
  display: flex;
  align-items: center;
  gap: 8px;
  min-height: 42px;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #f8fafc;
  color: var(--text);
  font-weight: 800;
}

.check-row input {
  width: 18px;
  height: 18px;
  accent-color: var(--primary);
}

.book-editor-index {
  margin-top: 8px;
  padding-top: 18px;
  border-top: 1px solid var(--line);
}

.book-editor-index h3 {
  margin: 0 0 4px;
}

.book-index-list {
  display: grid;
  gap: 12px;
  margin-top: 14px;
}

.book-index-topic,
.book-editor-subtopic,
.book-editor-preview {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
}

.book-index-topic-header,
.book-editor-subtopic-head {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
  justify-content: space-between;
  padding: 14px;
}

.book-index-topic-header strong,
.book-editor-subtopic-head strong {
  flex: 1 1 260px;
  color: var(--ink);
  font-size: 16px;
}

.book-index-topic-body {
  padding: 0 14px 14px;
}

.compact-editor-grid {
  gap: 10px;
}

.book-editor-section-title {
  margin: 14px 0 8px;
  color: var(--primary);
  font-size: 13px;
  font-weight: 900;
  letter-spacing: .06em;
  text-transform: uppercase;
}

.book-editor-files {
  display: grid;
  gap: 8px;
}

.book-editor-file-row {
  display: grid;
  grid-template-columns: 54px minmax(180px, 1fr) 170px 80px 130px minmax(120px, auto) auto auto;
  gap: 8px;
  align-items: center;
  padding: 10px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #f8fafc;
}

.book-editor-file-icon {
  display: grid;
  place-items: center;
  min-height: 42px;
  border-radius: 8px;
  background: #eef6ff;
  color: #133f8a;
  font-size: 12px;
  font-weight: 900;
}

.book-editor-file-meta,
.compact-note {
  color: var(--muted);
  font-size: 13px;
}

.mini-input {
  min-width: 74px;
}

.book-editor-file-picker {
  display: inline-flex;
  align-items: center;
  width: fit-content;
  cursor: pointer;
}

.book-editor-file-picker input {
  position: absolute;
  width: 1px;
  height: 1px;
  opacity: 0;
  pointer-events: none;
}

.book-editor-subtopics {
  display: grid;
  gap: 10px;
}

.book-editor-subtopic {
  background: #fbfcff;
}

.book-editor-preview {
  margin-top: 16px;
  padding: 16px;
  background: #f8fafc;
}

.preview-topic {
  margin-top: 10px;
}

.preview-subtopic {
  margin: 8px 0 0 20px;
}

.book-card {
  overflow: hidden;
}

.book-cover-link {
  position: relative;
  display: block;
  color: inherit;
  text-decoration: none;
  cursor: pointer;
}

.book-cover-link:focus-visible {
  outline: 3px solid rgba(79, 70, 229, 0.45);
  outline-offset: -3px;
}

.book-cover-link .book-cover {
  transition: transform 0.18s ease, filter 0.18s ease;
}

.book-cover-link:hover .book-cover {
  filter: brightness(0.98);
  transform: scale(1.01);
}

.book-cover-click-layer {
  position: absolute;
  inset: 0;
  z-index: 2;
}

.book-cover {
  height: 174px;
  display: grid;
  place-items: center;
  padding: 18px;
  background: linear-gradient(135deg, #f1f7ff, #ffe6ef);
  color: #4f46e5;
  font-weight: 900;
  text-align: center;
  white-space: pre-line;
}

.book-cover-image,
.book-cover-html {
  padding: 0;
  overflow: hidden;
  background: #f8fafc;
}

.book-cover-image img,
.book-cover-html iframe {
  width: 100%;
  height: 100%;
  display: block;
  border: 0;
}

.book-cover-image img {
  object-fit: cover;
}

.book-cover.dark {
  color: #fff;
}

.book-body {
  padding: 16px;
}

.book-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 8px;
}

.book-title {
  margin: 0 0 4px;
  font-size: 16px;
}

.book-desc {
  min-height: 42px;
  color: var(--muted);
  font-size: 13px;
}

.book-commercial-row {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-top: 14px;
}

.book-action-row {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-top: 14px;
}

.book-action-row .share-row {
  display: contents;
}

.book-action-row .btn {
  min-height: 44px;
}

.course-detail-section {
  padding-top: 24px;
}

.course-detail-hero {
  display: grid;
  grid-template-columns: minmax(260px, 360px) 1fr;
  gap: 24px;
  align-items: stretch;
  margin: 18px 0 22px;
}

.course-cover-wrap .book-cover {
  height: 100%;
  min-height: 330px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
}

.course-detail-main {
  display: grid;
  align-content: center;
  gap: 14px;
  padding: 24px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: #fff;
  box-shadow: var(--shadow);
}

.course-rating-line,
.course-action-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px;
}

.course-rating-line {
  color: var(--muted);
}

.course-rating-line strong {
  color: var(--ink);
  font-size: 22px;
}

.course-detail-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.course-wide {
  grid-column: 1 / -1;
}

.course-feature-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.course-feature,
.course-preview-item,
.course-topic-row,
.course-subtopic-row {
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #f8fafc;
}

.course-feature {
  padding: 12px;
}

.course-feature strong {
  display: block;
  color: var(--muted);
  font-size: 12px;
  text-transform: uppercase;
}

.course-feature.enabled strong {
  color: var(--success);
}

.course-preview-list,
.course-topic-list,
.course-faq {
  display: grid;
  gap: 10px;
}

.course-preview-item,
.course-topic-row,
.course-subtopic-row {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  align-items: center;
  padding: 12px;
}

.course-preview-free {
  background: #ecfdf3;
  border-color: #bbf7d0;
}

.course-preview-item p,
.course-topic-row p {
  margin: 4px 0 0;
  color: var(--muted);
  font-size: 13px;
}

.course-subtopic-row {
  margin-left: 18px;
  background: #fff;
}

.course-faq details {
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 12px;
  background: #fff;
}

.course-faq summary {
  cursor: pointer;
  font-weight: 900;
}

.course-faq p {
  margin: 8px 0 0;
  color: var(--muted);
}

.subscriber-count-badge {
  display: inline-flex;
  min-width: 40px;
  height: 34px;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
  background: #eef2ff;
  color: var(--accent);
  font-weight: 900;
  font-size: 16px;
}

.book-counts-table {
  min-width: 760px;
}

.book-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-top: 16px;
}

.blog-card {
  overflow: hidden;
}

.blog-image {
  width: 100%;
  height: 176px;
  display: block;
  object-fit: cover;
  background: #fff;
  border-bottom: 1px solid var(--line);
}

.blog-body {
  padding: 16px;
}

.blog-title {
  margin: 0 0 6px;
  font-size: 18px;
  line-height: 1.25;
}

.blog-desc {
  min-height: 54px;
  color: var(--muted);
  font-size: 13px;
}

.narrow {
  max-width: 900px;
}

.blog-detail-head {
  display: grid;
  gap: 12px;
  margin-bottom: 22px;
}

.blog-hero-image {
  width: 100%;
  max-height: 420px;
  object-fit: contain;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.blog-content {
  margin-top: 22px;
  padding: 24px;
  color: #1f2937;
  font-size: 16px;
}

.blog-content p {
  margin: 0 0 16px;
}

.blog-panel {
  margin-top: 22px;
}

.blog-panel h3 {
  margin: 0 0 12px;
  font-size: 20px;
}

.formula-list {
  display: grid;
  gap: 10px;
}

.formula-list code {
  display: block;
  padding: 12px 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
  color: var(--primary-dark);
  font-weight: 800;
  white-space: normal;
}

.blog-gallery {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.blog-gallery img {
  width: 100%;
  height: 220px;
  object-fit: cover;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
}

.blog-video {
  width: 100%;
  aspect-ratio: 16 / 9;
  border: 0;
  border-radius: var(--radius);
  background: #000;
}

.blog-blocks {
  display: grid;
  gap: 18px;
  margin-top: 18px;
}

.blog-flow-block {
  border-top: 1px solid var(--line);
  padding-top: 18px;
}

.blog-flow-block h3 {
  margin: 0 0 10px;
  font-size: 20px;
}

.blog-flow-block p:last-child {
  margin-bottom: 0;
}

.blog-rich-html {
  display: grid;
  gap: 12px;
  color: var(--ink);
  line-height: 1.75;
}

.blog-rich-html img,
.blog-rich-html video,
.blog-rich-html iframe,
.blog-rich-html canvas,
.blog-rich-html svg,
.blog-rich-html table {
  max-width: 100%;
}

.blog-rich-html table {
  border-collapse: collapse;
}

.blog-rich-html td,
.blog-rich-html th {
  border: 1px solid var(--line);
  padding: 10px 12px;
}

.blog-html-frame {
  width: 100%;
  min-height: 420px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
}

.blog-block-image {
  width: 100%;
  max-height: 430px;
  object-fit: contain;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.blog-audio {
  width: 100%;
}

.blog-file-card {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fbfcff;
}

.blog-file-meta {
  min-width: 0;
  flex: 1;
}

.blog-file-meta strong {
  display: block;
  color: var(--ink);
}

.blog-file-meta p {
  margin: 4px 0;
  color: var(--muted);
}

.blog-file-meta small {
  display: block;
  overflow-wrap: anywhere;
  color: #64748b;
}

.share-row {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.share-row.compact .btn {
  padding: 8px 12px;
  font-size: 13px;
}

.actions > .share-row.compact {
  display: contents;
}

.resource-inline-actions {
  display: inline-flex;
  gap: 8px;
  flex-wrap: wrap;
}

.compact-textarea {
  min-height: 96px;
}

.tall-textarea {
  min-height: 220px;
}

.blog-category-card {
  padding: 16px;
}

.price {
  font-size: 20px;
  font-weight: 900;
}

.book-price-block {
  display: flex;
  align-items: center;
  gap: 10px;
  min-width: 112px;
  flex-wrap: wrap;
}

.book-price-block.compact {
  min-width: 0;
}

.book-price-row {
  display: flex;
  align-items: baseline;
  gap: 10px;
  flex-wrap: wrap;
}

.price-original {
  color: var(--muted);
  font-size: 15px;
  font-weight: 800;
  text-decoration: line-through;
  text-decoration-thickness: 2px;
}

.discount-deadline {
  width: fit-content;
  border-radius: 999px;
  background: #fff4dd;
  color: #9a5600;
  font-size: 12px;
  font-weight: 900;
  padding: 7px 12px;
  line-height: 1.2;
}

.admin-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 22px;
  width: min(var(--container), calc(100% - 28px));
  margin: 26px auto 52px;
}

.admin-layout.menu-hidden,
.admin-layout-full {
  grid-template-columns: minmax(0, 1fr);
}

.admin-sidebar {
  position: sticky;
  top: 92px;
  height: fit-content;
  padding: 14px;
}

.admin-layout > .admin-sidebar,
.admin-menu-restore {
  display: none !important;
}

.admin-sidebar-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 6px 4px 12px;
  color: var(--ink);
}

.icon-btn {
  width: 34px;
  height: 34px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #ffffff;
  color: var(--muted);
  display: inline-grid;
  place-items: center;
  font-weight: 900;
  cursor: pointer;
}

.icon-btn:hover {
  color: var(--primary-dark);
  border-color: #c9c4ff;
  background: #f7f6ff;
}

.admin-menu-restore {
  position: sticky;
  top: 92px;
  z-index: 15;
  width: fit-content;
  margin-bottom: -6px;
}

.admin-content {
  min-width: 0;
}

.side-nav a,
.side-link {
  min-height: 40px;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 0 12px;
  border-radius: var(--radius);
  color: #344054;
  font-weight: 800;
  font-size: 13px;
}

.side-nav a.active,
.side-nav a:hover,
.side-link.active,
.side-link:hover {
  background: #f0efff;
  color: var(--primary-dark);
}

.stat-card {
  display: flex;
  align-items: center;
  gap: 14px;
  min-height: 98px;
  padding: 18px;
}

.stat-card strong {
  display: block;
  font-size: 22px;
}

.stat-card span {
  color: var(--muted);
  font-size: 12px;
}

.quick-actions {
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  gap: 12px;
}

.quick-card {
  min-height: 78px;
  display: grid;
  place-items: center;
  align-content: center;
  gap: 6px;
  border: 0;
  border-radius: var(--radius);
  color: #fff;
  font-weight: 900;
}

.quick-card small {
  font-size: 11px;
  opacity: 0.9;
}

.quick-card.blue { background: #5066e8; }
.quick-card.yellow { background: #d89b18; }
.quick-card.pink { background: #e94c84; }
.quick-card.green { background: #0cb981; }
.quick-card.purple { background: #7361f2; }
.quick-card.coral { background: #ef6a56; }

.payment-tabs {
  align-items: stretch;
  gap: 8px;
}

.payment-tabs .tab {
  min-height: 40px;
}

.payment-summary-grid,
.settings-grid,
.report-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
  margin: 18px 0;
}

.payment-chart,
.setting-card,
.report-card {
  padding: 16px;
}

.payment-chart h3,
.setting-card strong,
.report-card strong {
  margin: 0 0 12px;
  display: block;
}

.chart-bars {
  display: grid;
  gap: 10px;
}

.chart-row {
  display: grid;
  grid-template-columns: minmax(92px, 1fr) minmax(120px, 2fr) auto;
  align-items: center;
  gap: 10px;
  font-size: 12px;
  color: var(--muted);
}

.chart-row div {
  height: 9px;
  overflow: hidden;
  border-radius: 999px;
  background: #eef2ff;
}

.chart-row i {
  display: block;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, #4f46e5, #0ea5e9);
}

.chart-row strong {
  color: var(--ink);
  font-size: 12px;
}

.payment-toolbar {
  display: grid;
  gap: 14px;
  margin-bottom: 16px;
}

.setting-card span,
.report-card p {
  color: var(--muted);
  font-size: 13px;
}

.settings-grid .span-2 {
  grid-column: 1 / -1;
}

.table-card {
  overflow-x: auto;
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  min-width: 680px;
}

.data-table th,
.data-table td {
  padding: 14px 16px;
  border-bottom: 1px solid var(--line);
  text-align: left;
  vertical-align: middle;
}

.data-table th {
  color: #475467;
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.empty-state {
  min-height: 260px;
  display: grid;
  place-items: center;
  text-align: center;
  color: var(--muted);
  padding: 36px;
}

.empty-state strong {
  display: block;
  color: var(--ink);
  margin-bottom: 4px;
}

.group-card,
.class-card {
  padding: 18px;
}

.group-head,
.class-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
}

.group-actions,
.class-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 18px;
}

.class-thumb {
  height: 150px;
  display: grid;
  place-items: center;
  color: #d9468b;
  background: linear-gradient(135deg, #fff1f6, #f2eaff);
  border-radius: var(--radius);
  margin-bottom: 14px;
  font-size: 26px;
  font-weight: 900;
}

.book-access {
  display: grid;
  grid-template-columns: 120px 1fr auto;
  gap: 22px;
  align-items: center;
  background: #f3f0ff;
  border-color: #b6a7ff;
  padding: 18px;
}

.book-access .book-cover {
  width: 112px;
  height: 112px;
  border-radius: var(--radius);
  font-size: 16px;
}

.topic-list {
  display: grid;
  gap: 12px;
}

.topic-row,
.subtopic-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  gap: 12px;
  min-height: 56px;
  padding: 0 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
}

.topic-row {
  font-weight: 900;
}

.subtopic-row {
  margin-left: 18px;
}

.resource-actions {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.resource-actions.inline-files {
  justify-content: flex-start;
  margin-top: 8px;
}

.resource-admin-actions {
  display: inline-flex;
  gap: 4px;
  align-items: center;
  flex-wrap: wrap;
}

.resource-chip {
  min-height: 28px;
  padding: 0 10px;
  border: 0;
  border-radius: 999px;
  background: #f0efff;
  color: var(--primary-dark);
  font-size: 11px;
  font-weight: 900;
}

.resource-chip:hover {
  background: var(--primary);
  color: #fff;
}

.resource-chip-add {
  background: #e8fbf2;
  color: var(--success);
}

.resource-chip-danger {
  background: var(--danger-soft);
  color: var(--danger);
}

.resource-chip-preview {
  background: #ecfdf3;
  color: var(--success);
}

.cta-band {
  color: #fff;
  background: radial-gradient(circle at 48% 10%, rgba(85, 70, 232, 0.36), transparent 24%),
    linear-gradient(135deg, #070b24, #0b1438 60%, #050816);
  text-align: center;
  padding: 70px 0;
}

.cta-band h2 {
  margin: 0 auto 12px;
  max-width: 620px;
  font-size: 34px;
  line-height: 1.12;
}

.cta-band p {
  margin: 0 auto 24px;
  max-width: 560px;
  color: #d7deef;
}

.footer {
  background: #060a20;
  color: #dbe2f2;
  padding: 42px 0 24px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 0.8fr 1fr 1fr;
  gap: 28px;
}

.footer h4 {
  margin: 0 0 12px;
  color: #fff;
}

.footer p,
.footer a {
  color: #b7c1d9;
  font-size: 13px;
}

.footer-links {
  display: grid;
  gap: 8px;
}

.socials {
  display: flex;
  gap: 8px;
  margin-top: 16px;
}

.socials a {
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: 50%;
}

.socials-compact {
  margin-top: 0;
  margin-right: 10px;
}

.socials-compact a {
  width: 30px;
  height: 30px;
}

.floating-whatsapp {
  position: fixed;
  right: 18px;
  bottom: 18px;
  z-index: 30;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 12px 16px;
  border-radius: 999px;
  border: 1px solid #a7f3d0;
  background: #10b981;
  color: #fff;
  box-shadow: 0 18px 36px rgba(16, 185, 129, 0.26);
}

.floating-whatsapp.left {
  right: auto;
  left: 18px;
}

.floating-whatsapp span {
  width: 28px;
  height: 28px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.18);
}

.checkbox-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
}

.check-chip {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fbfcff;
}

.social-admin-icon {
  width: 34px;
  height: 34px;
  display: inline-grid;
  place-items: center;
  border-radius: 50%;
  background: #eef2ff;
  color: var(--primary);
  font-weight: 800;
}

.newsletter {
  display: flex;
  gap: 8px;
  margin-top: 10px;
}

.newsletter input {
  min-width: 0;
  flex: 1;
  min-height: 38px;
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.08);
  color: #fff;
  padding: 0 12px;
}

.footer-bottom {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  margin-top: 30px;
  padding-top: 18px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-bottom nav {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.modal-backdrop {
  position: fixed;
  inset: 0;
  z-index: 80;
  display: grid;
  place-items: center;
  padding: 20px;
  background: rgba(5, 8, 22, 0.62);
}

.modal {
  width: min(720px, 100%);
  max-height: min(88vh, 820px);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  background: #fff;
  border-radius: var(--radius);
  box-shadow: 0 30px 90px rgba(0, 0, 0, 0.28);
}

.modal-header,
.modal-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 16px 18px;
  border-bottom: 1px solid var(--line);
}

.modal-footer {
  justify-content: flex-end;
  border-top: 1px solid var(--line);
  border-bottom: 0;
}

.modal-header h2 {
  margin: 0;
  font-size: 20px;
}

.modal-body {
  overflow: auto;
  padding: 18px;
}

.fullscreen-modal {
  width: min(1480px, calc(100vw - 16px));
  height: calc(100vh - 16px);
  max-height: none;
  border-radius: 12px;
}

.fullscreen-modal .modal-header {
  flex: 0 0 auto;
  padding: 18px 26px;
}

.fullscreen-modal .modal-header h2 {
  font-size: 26px;
}

.fullscreen-modal .modal-body {
  flex: 1 1 auto;
  min-height: 0;
  padding: 18px 26px 28px;
}

.fullscreen-modal .modal-footer {
  flex: 0 0 auto;
  padding: 14px 26px;
}

.fullscreen-modal .form-grid {
  grid-template-columns: repeat(4, minmax(210px, 1fr));
  gap: 16px 18px;
}

.fullscreen-modal .form-grid .span-2,
.fullscreen-modal .math-question-builder,
.fullscreen-modal .legacy-question-format {
  grid-column: 1 / -1;
}

.fullscreen-modal .question-option-builder-grid {
  grid-template-columns: 1fr;
}

.viewer-modal {
  width: min(1320px, calc(100vw - 20px));
  height: min(860px, calc(100dvh - 20px));
  max-height: none;
  background: #080d23;
  color: #fff;
}

.viewer-modal .modal-header {
  border-bottom-color: rgba(255, 255, 255, 0.12);
}

.viewer-body {
  position: relative;
  flex: 1;
  min-height: 0;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  padding: clamp(10px, 2vw, 20px) clamp(10px, 2.4vw, 24px) clamp(12px, 2.4vw, 24px);
}

.viewer-security-strip {
  position: absolute;
  top: 14px;
  left: 18px;
  right: 18px;
  z-index: 4;
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 8px;
}

.viewer-security-strip span {
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: 999px;
  padding: 6px 10px;
  background: rgba(8, 13, 35, 0.76);
  color: #fff;
  font-size: 11px;
  font-weight: 900;
}

.viewer-toolbar {
  position: relative;
  z-index: 4;
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 8px;
  margin: 6px 0 10px;
}

.viewer-scale-chip {
  min-width: 72px;
  height: 38px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.1);
  color: #fff;
  font-weight: 900;
}

.viewer-scroll-area {
  position: relative;
  z-index: 2;
  flex: 1;
  min-height: 0;
  width: 100%;
  overflow: auto;
  padding: clamp(8px, 1.8vw, 14px) 4px clamp(12px, 2vw, 18px);
  display: grid;
  align-items: start;
  justify-items: center;
  -webkit-overflow-scrolling: touch;
  overscroll-behavior: contain;
}

.viewer-capture-shield {
  position: absolute;
  inset: 0;
  z-index: 8;
  display: none;
  place-items: center;
  align-content: center;
  gap: 12px;
  padding: 28px;
  text-align: center;
  color: #fff;
  background: rgba(2, 6, 23, 0.92);
  pointer-events: none;
}

.viewer-capture-shield strong {
  font-size: clamp(24px, 4vw, 42px);
  line-height: 1.1;
}

.viewer-capture-shield span {
  max-width: 640px;
  color: rgba(255, 255, 255, 0.82);
  font-weight: 800;
  line-height: 1.5;
}

body.viewer-capture-active .viewer-capture-shield {
  display: grid;
}

body.viewer-capture-active .viewer-stage {
  filter: blur(16px) brightness(0.35);
  user-select: none;
}

body.viewer-capture-active .formula-sheet-detail {
  filter: blur(16px) brightness(0.4);
  user-select: none;
}

body.viewer-capture-active .viewer-watermark {
  z-index: 9;
  opacity: 0.32;
}

body.viewer-locked .viewer-stage,
body.viewer-locked .formula-sheet-detail {
  -webkit-user-select: none;
  user-select: none;
}

body.viewer-locked .viewer-stage img,
body.viewer-locked .formula-sheet-detail img {
  -webkit-user-drag: none;
  user-drag: none;
}

@media print {
  body.viewer-locked * {
    visibility: hidden !important;
  }

  body.viewer-locked::before {
    content: "Printing is restricted for protected RSN Edu content.";
    visibility: visible;
    display: block;
    padding: 36px;
    color: #111827;
    font: 700 18px/1.5 system-ui, sans-serif;
  }
}

.viewer-fullscreen-actions {
  position: absolute;
  top: 14px;
  right: 14px;
  z-index: 5;
  display: none;
  align-items: center;
  gap: 0;
  overflow: hidden;
  border-radius: 0;
  background: #fff2d6;
  border: 1px solid rgba(148, 113, 58, 0.18);
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.12);
}

[data-viewer-scroll]:fullscreen .viewer-fullscreen-actions {
  display: flex;
  position: fixed;
  top: 10px;
  right: 10px;
}

[data-viewer-scroll]:fullscreen {
  width: 100vw;
  height: 100dvh;
  padding: 56px 12px 18px;
  background: #080d23;
  overflow: auto;
}

.viewer-window-btn {
  width: 46px;
  height: 34px;
  display: inline-grid;
  place-items: center;
  border: 0;
  border-radius: 0;
  background: transparent;
  color: #6c5634;
  font-size: 24px;
  line-height: 1;
  font-weight: 400;
  cursor: pointer;
}

.viewer-window-btn:hover,
.viewer-window-btn:focus-visible {
  background: rgba(246, 174, 61, 0.18);
  outline: 0;
}

.viewer-window-close {
  font-size: 28px;
}

.viewer-window-close:hover,
.viewer-window-close:focus-visible {
  background: #f9d8d4;
  color: #9f2f24;
}

.viewer-watermark {
  position: absolute;
  inset: 0;
  pointer-events: none;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  grid-auto-rows: 140px;
  opacity: 0.12;
  transform: rotate(-18deg) scale(1.08);
  color: #fff;
  font-weight: 900;
  font-size: 13px;
}

.viewer-watermark-moving {
  animation: watermarkDrift 18s linear infinite alternate;
}

.viewer-watermark span {
  display: grid;
  place-items: center;
  text-align: center;
}

@keyframes watermarkDrift {
  from {
    transform: rotate(-18deg) scale(1.08) translate3d(-24px, -16px, 0);
  }
  to {
    transform: rotate(-18deg) scale(1.08) translate3d(28px, 22px, 0);
  }
}

.viewer-stage {
  --viewer-scale: 1;
  position: relative;
  z-index: 2;
  width: min(980px, 100%);
  min-height: clamp(320px, 62dvh, 680px);
  display: grid;
  place-items: center;
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: var(--radius);
  background: #fff;
  color: #111827;
  overflow: visible;
  transform: scale(var(--viewer-scale));
  transform-origin: top center;
  transition: transform 120ms ease;
}

.viewer-stage.video,
.viewer-stage.audio {
  background: linear-gradient(135deg, #111827, #1f2a44);
  color: #fff;
}

.viewer-content {
  width: min(920px, calc(100% - 18px));
  text-align: center;
}

.viewer-zoom-target {
  width: 100%;
}

.viewer-content h3 {
  margin: 0 0 10px;
  font-size: clamp(20px, 2.4vw, 28px);
  line-height: 1.15;
}

.viewer-meta-strip {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 14px;
}

.viewer-meta-strip span {
  padding: 7px 11px;
  border-radius: 999px;
  background: #eef2ff;
  color: #3730a3;
  font-size: 13px;
  font-weight: 900;
}

.viewer-controls {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 18px;
}

.progress-track {
  width: min(520px, 100%);
  height: 8px;
  margin: 20px auto 0;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.18);
  overflow: hidden;
}

.progress-track span {
  display: block;
  width: 46%;
  height: 100%;
  background: #7cddc4;
}

.viewer-stage-document {
  padding: clamp(12px, 2.4vw, 26px) 0;
}

.viewer-pdf-stack,
.viewer-html-flow {
  width: min(900px, calc(100% - 18px));
  margin: 0 auto;
}

.viewer-html-frame-wrap {
  width: min(1040px, calc(100% - 18px));
  margin: 0 auto;
}

.secure-content-frame {
  width: 100%;
  height: clamp(360px, 66dvh, 760px);
  min-height: 360px;
  margin-top: 18px;
  border: 1px solid #d0d5dd;
  border-radius: 8px;
  background: #fff;
}

.viewer-pdf-page,
.viewer-reading-block {
  padding: clamp(16px, 3vw, 28px);
  margin-bottom: 18px;
  border-radius: 8px;
  background: #fff;
  border: 1px solid #d0d5dd;
  box-shadow: 0 18px 40px rgba(15, 23, 42, 0.08);
  text-align: left;
}

.viewer-pdf-page {
  min-height: clamp(420px, 68dvh, 760px);
}

.viewer-source-block {
  margin-top: 18px;
  padding: 14px;
  border: 1px solid #d0d5dd;
  border-radius: 8px;
  background: #f8fafc;
  text-align: left;
}

.viewer-source-block summary {
  cursor: pointer;
  font-weight: 900;
}

.viewer-source-block pre,
.viewer-reading-block pre {
  overflow: auto;
  max-width: 100%;
  padding: 14px;
  border-radius: 8px;
  background: #0f172a;
  color: #e2e8f0;
  white-space: pre-wrap;
}

.viewer-image-stage {
  width: min(960px, calc(100% - 18px));
}

.viewer-visual-frame {
  display: grid;
  place-items: center;
  min-height: clamp(300px, 60dvh, 680px);
  padding: 18px;
  border: 1px solid #d0d5dd;
  border-radius: 8px;
  background: #f8fafc;
  overflow: auto;
}

.viewer-visual-frame img,
.viewer-visual-frame svg {
  max-width: 100%;
  max-height: min(72dvh, 760px);
  height: auto;
}

.viewer-image-placeholder {
  display: grid;
  place-items: center;
  width: 100%;
  min-height: 320px;
  border-radius: 8px;
  background: linear-gradient(135deg, #eef2ff, #ecfeff);
  color: var(--primary);
  font-size: 30px;
  font-weight: 900;
}

.viewer-pdf-page h4,
.viewer-reading-block h4 {
  margin: 0 0 10px;
}

.viewer-media-panel {
  width: min(760px, 100%);
  margin: 18px auto 0;
  padding: 20px;
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.14);
}

.video-stage-screen {
  min-height: 280px;
  border-radius: 10px;
  display: grid;
  place-items: center;
  background: linear-gradient(135deg, rgba(255,255,255,0.08), rgba(124,221,196,0.12));
  color: #fff;
  font-size: 28px;
  font-weight: 900;
}

.audio-waveform {
  min-height: 160px;
  display: flex;
  align-items: end;
  justify-content: center;
  gap: 8px;
}

.audio-waveform i {
  width: 10px;
  border-radius: 999px;
  background: linear-gradient(180deg, #7cddc4, #4c7cf0);
  display: block;
}

.security-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.security-grid .span-2 {
  grid-column: 1 / -1;
}

.security-rule-grid {
  display: grid;
  gap: 8px;
}

.security-rule {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 10px 12px;
  background: #f8fafc;
  color: #344054;
  font-weight: 800;
}

.inline-table {
  max-height: 360px;
  overflow: auto;
}

#toast-root {
  position: fixed;
  right: 18px;
  bottom: 18px;
  z-index: 100;
  display: grid;
  gap: 10px;
}

.toast {
  min-width: min(360px, calc(100vw - 36px));
  padding: 14px 16px;
  border-radius: var(--radius);
  background: #101828;
  color: #fff;
  box-shadow: var(--shadow);
  font-weight: 800;
}

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

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

.policy-block {
  display: grid;
  gap: 18px;
}

.policy-block h3 {
  margin: 0 0 6px;
}

.policy-block ul {
  margin: 0;
  padding-left: 20px;
  color: var(--muted);
}

.support-page-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.support-card,
.support-inquiry-card {
  align-content: start;
}

.support-card h2,
.support-wide h2 {
  margin: 8px 0 10px;
}

.support-highlight-list,
.support-contact-list {
  display: grid;
  gap: 10px;
  margin-top: 16px;
}

.support-highlight-list span,
.support-contact-list div {
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #f8fbff;
  padding: 11px 12px;
}

.support-contact-list div {
  display: grid;
  gap: 4px;
}

.support-contact-list span {
  color: var(--muted);
  overflow-wrap: anywhere;
}

.support-wide {
  grid-column: 1 / -1;
}

.sitemap-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.sitemap-card h3 {
  margin: 0 0 12px;
}

.sitemap-links {
  display: grid;
  gap: 8px;
}

.sitemap-links a {
  color: var(--primary-dark);
  font-weight: 800;
}

@media (max-width: 980px) {
  .viewer-modal {
    width: calc(100vw - 14px);
    height: calc(100dvh - 14px);
  }

  .viewer-stage {
    width: 100%;
    min-height: clamp(320px, 64dvh, 680px);
  }

  .viewer-content {
    width: calc(100% - 12px);
  }

  .viewer-pdf-stack,
  .viewer-html-flow,
  .viewer-html-frame-wrap,
  .viewer-image-stage {
    width: calc(100% - 12px);
  }

  .fullscreen-modal .form-grid,
  .fullscreen-modal .question-option-builder-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .fullscreen-modal .question-option-builder-grid {
    grid-template-columns: 1fr;
  }

  .question-builder-part-row {
    grid-template-columns: 90px 110px minmax(180px, 1fr);
  }

  .compact-file-input {
    grid-column: 3;
  }

  .topbar-inner {
    height: auto;
    grid-template-columns: 1fr;
    padding: 14px 0;
  }

  .brand,
  .top-actions {
    justify-content: center;
  }

  .nav-pills {
    justify-content: flex-start;
    overflow-x: auto;
    padding-bottom: 2px;
  }

  .hero-grid {
    grid-template-columns: 1fr;
    min-height: auto;
  }

  .hero-title {
    font-size: 40px;
  }

  .hero-media {
    min-height: 280px;
  }

  .stat-strip,
  .feature-grid,
  .book-grid,
  .blog-grid,
  .category-grid,
  .module-grid,
  .plan-grid,
  .blog-grid.admin,
  .blog-grid.compact,
  .admin-grid,
  .quick-actions,
  .footer-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .admin-grid.two {
    grid-template-columns: 1fr;
  }

  .payment-summary-grid,
  .registration-layout,
  .settings-grid,
  .report-grid {
    grid-template-columns: 1fr;
  }

  .lms-two-col {
    grid-template-columns: 1fr;
  }

  .admin-test-card {
    padding: 16px;
  }

  .course-detail-hero,
  .course-detail-grid {
    grid-template-columns: 1fr;
  }

  .course-wide {
    grid-column: auto;
  }

  .course-cover-wrap .book-cover {
    min-height: 260px;
  }

  .admin-layout {
    grid-template-columns: 1fr;
  }

  .admin-sidebar {
    position: static;
  }

  .side-nav {
    display: flex;
    overflow-x: auto;
    gap: 8px;
  }

  .side-link {
    white-space: nowrap;
  }

  .search-row {
    grid-template-columns: 1fr 1fr;
  }

  .book-access {
    grid-template-columns: 90px 1fr;
  }

  .cart-row {
    grid-template-columns: 104px minmax(0, 1fr);
  }

  .cart-row .btn {
    grid-column: 1 / -1;
    justify-self: start;
  }

  .book-access .actions {
    grid-column: 1 / -1;
  }
}

@media (max-width: 640px) {
  .modal-backdrop {
    padding: 0;
  }

  .viewer-modal {
    width: 100vw;
    height: 100dvh;
    border-radius: 0;
  }

  .viewer-modal .modal-header {
    padding: 10px 12px;
  }

  .viewer-modal .modal-header h2 {
    max-width: calc(100vw - 80px);
    overflow: hidden;
    font-size: 17px;
    line-height: 1.2;
    text-overflow: ellipsis;
    white-space: nowrap;
  }

  .viewer-body {
    padding: 8px 8px 12px;
  }

  .viewer-toolbar {
    justify-content: flex-start;
    gap: 6px;
    overflow-x: auto;
    padding-bottom: 2px;
  }

  .viewer-toolbar .btn {
    min-height: 34px;
    padding: 0 10px;
    white-space: nowrap;
  }

  .viewer-scale-chip {
    min-width: 58px;
    height: 34px;
  }

  .viewer-scroll-area {
    padding: 8px 0 12px;
  }

  .viewer-stage {
    width: 100%;
    min-height: calc(100dvh - 156px);
    border-radius: 8px;
  }

  .viewer-stage-document {
    padding: 10px 0;
  }

  .viewer-content {
    width: calc(100% - 8px);
  }

  .viewer-meta-strip {
    justify-content: flex-start;
    gap: 6px;
  }

  .viewer-meta-strip span {
    padding: 6px 8px;
    font-size: 11px;
  }

  .viewer-pdf-stack,
  .viewer-html-flow,
  .viewer-html-frame-wrap,
  .viewer-image-stage {
    width: calc(100% - 8px);
  }

  .viewer-pdf-page,
  .viewer-reading-block {
    min-height: calc(100dvh - 190px);
    padding: 14px;
  }

  .secure-content-frame {
    height: calc(100dvh - 210px);
    min-height: 360px;
  }

  .viewer-visual-frame {
    min-height: calc(100dvh - 210px);
    padding: 10px;
  }

  .viewer-media-panel {
    padding: 14px;
  }

  .viewer-controls {
    justify-content: flex-start;
  }

  .viewer-watermark {
    grid-template-columns: repeat(2, 1fr);
    grid-auto-rows: 110px;
    font-size: 10px;
  }

  [data-viewer-scroll]:fullscreen {
    padding: 48px 6px 10px;
  }

  [data-viewer-scroll]:fullscreen .viewer-stage {
    min-height: calc(100dvh - 70px);
  }

  [data-viewer-scroll]:fullscreen .secure-content-frame,
  [data-viewer-scroll]:fullscreen .viewer-visual-frame,
  [data-viewer-scroll]:fullscreen .viewer-pdf-page,
  [data-viewer-scroll]:fullscreen .viewer-reading-block {
    min-height: calc(100dvh - 92px);
    height: calc(100dvh - 92px);
  }

  .fullscreen-modal {
    width: 100vw;
    height: 100dvh;
    border-radius: 0;
  }

  .fullscreen-modal .form-grid,
  .fullscreen-modal .question-option-builder-grid {
    grid-template-columns: 1fr;
  }

  .question-builder-part-row {
    grid-template-columns: 1fr;
  }

  .compact-file-input {
    grid-column: auto;
  }

  body {
    font-size: 14px;
  }

  .container,
  .topbar-inner,
  .hero-grid,
  .admin-layout {
    width: min(100% - 20px, var(--container));
  }

  .section {
    padding: 34px 0;
  }

  .hero-title,
  .page-title {
    font-size: 32px;
  }

  .stat-strip,
  .feature-grid,
  .book-grid,
  .blog-grid,
  .category-grid,
  .module-grid,
  .support-page-grid,
  .registration-layout,
  .book-grid.compact,
  .course-feature-grid,
  .plan-grid,
  .blog-grid.admin,
  .blog-grid.compact,
  .admin-grid,
  .quick-actions,
  .class-grid,
  .group-grid,
  .blog-gallery,
  .footer-grid,
  .search-row,
  .form-grid,
  .security-grid {
    grid-template-columns: 1fr;
  }

  .module-card {
    grid-template-columns: 1fr;
  }

  .test-start-panel,
  .test-row-card,
  .test-nav-actions {
    align-items: stretch;
    flex-direction: column;
  }

  .test-row-meta {
    justify-content: flex-start;
  }

  .test-detail-grid {
    grid-template-columns: 1fr;
  }

  .answer-comparison {
    grid-template-columns: 1fr;
  }

  .test-nav-actions .btn {
    width: 100%;
  }

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

  .question-option-builder-grid {
    grid-template-columns: 1fr;
  }

  .chart-row {
    grid-template-columns: 1fr;
  }

  .toolbar {
    align-items: flex-start;
    flex-direction: column;
  }

  .book-access {
    grid-template-columns: 1fr;
  }

  .cart-row,
  .cart-summary {
    grid-template-columns: 1fr;
    align-items: stretch;
  }

  .cart-summary {
    flex-direction: column;
  }

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

  .support-wide {
    grid-column: auto;
  }

  .category-card {
    grid-template-columns: 1fr;
  }

  .category-visual {
    width: 100%;
  }

  .book-access .book-cover {
    width: 100%;
  }

  .subtopic-row,
  .topic-row {
    grid-template-columns: 1fr;
    align-items: start;
    padding: 12px;
  }

  .subtopic-row {
    margin-left: 0;
  }

  .resource-actions {
    justify-content: flex-start;
  }

  .book-index-topic-header,
  .book-editor-subtopic-head {
    align-items: stretch;
    flex-direction: column;
  }

  .book-editor-file-row {
    grid-template-columns: 1fr;
  }

  .book-editor-file-icon {
    justify-content: start;
    padding: 0 12px;
  }

  .input-with-button {
    grid-template-columns: 1fr;
  }

  .input-with-button .btn {
    width: 100%;
  }

  .blog-file-card {
    align-items: flex-start;
    flex-direction: column;
  }

  .footer-bottom {
    flex-direction: column;
  }

  .newsletter {
    flex-direction: column;
  }

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

@media (max-width: 720px) {
  .toggle-grid {
    grid-template-columns: 1fr;
  }

  .secure-content-frame {
    min-height: min(420px, calc(100dvh - 190px));
  }

  .viewer-meta-strip {
    justify-content: flex-start;
  }

  .viewer-content h3 {
    font-size: clamp(19px, 4.8vw, 22px);
  }

  .viewer-visual-frame {
    min-height: min(360px, calc(100dvh - 190px));
  }
}