/* MMM Study — Physics Subject Architecture Styles */
@import "../design_system.css";

:root {
  --subject-accent: #0D9488;
  --subj-phys-accent: #0D9488;
  --subj-phys-light: #F0FDFA;
  --subj-phys-border: #CCFBF1;
  --subj-phys-dark: #134E4A;
  --subj-phys-hover: #0F766E;
  --subj-phys-surface: #FFFFFF;
  --subj-phys-bg: #F8FAFC;
  --subj-phys-border-subtle: #F1F5F9;
  --subj-phys-text-primary: #0F172A;
  --subj-phys-text-secondary: #475569;
  --subj-phys-text-muted: #64748B;
  --subj-phys-radius: 10px;
  --subj-phys-radius-sm: 6px;
  --subj-phys-radius-lg: 12px;
}

/* Container Layout */
main {
  max-width: 1240px;
  width: 100%;
  margin: 0 auto;
  box-sizing: border-box;
}

/* Progressive Curriculum Navigation Bar */
.curriculum-nav-bar {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 22px;
  padding: 12px 18px;
  background: var(--surface-card, #FFFFFF);
  border: 1px solid var(--border-color, #E2E8F0);
  border-radius: var(--radius-md, 12px);
  box-shadow: var(--shadow-sm, 0 1px 3px rgba(11, 30, 54, 0.05));
  width: 100%;
  box-sizing: border-box;
}

.curriculum-back-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  border-radius: var(--radius-pill, 9999px);
  background: var(--brand-navy-900, #0B1E36);
  color: #FFFFFF;
  font-size: 13.5px;
  font-weight: 600;
  border: 1px solid var(--brand-gold-border, rgba(197, 155, 39, 0.3));
  cursor: pointer;
  transition: all 0.18s ease;
  font-family: inherit;
  min-height: 38px;
}

.curriculum-back-btn:hover {
  background: var(--brand-gold, #C59B27);
  color: var(--brand-navy-950, #071324);
  transform: translateX(-2px);
  box-shadow: 0 4px 12px rgba(197, 155, 39, 0.3);
}

.curriculum-breadcrumbs {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13.5px;
  color: var(--text-secondary, #64748B);
  flex-wrap: wrap;
}

.curriculum-breadcrumbs a,
.breadcrumb-link {
  color: var(--brand-navy-800, #143058);
  text-decoration: none;
  font-weight: 600;
  cursor: pointer;
  transition: color 0.15s ease;
}

.curriculum-breadcrumbs a:hover,
.breadcrumb-link:hover {
  color: var(--subj-phys-accent, #2563EB);
}

.curriculum-breadcrumbs .crumb-sep,
.curriculum-breadcrumbs .separator {
  color: #CBD5E1;
  user-select: none;
}

.curriculum-breadcrumbs strong,
.curriculum-breadcrumbs .current {
  color: var(--subj-phys-dark, #1E3A8A);
  font-weight: 700;
}

/* Screen 1: Primary Mode Selection (Notes vs Practice) */
.subject-mode-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
  margin-top: 18px;
  margin-bottom: 32px;
}

.mode-card {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  padding: 28px 24px;
  background: var(--surface-card, #FFFFFF);
  border: 2px solid var(--border-color, #E2E8F0);
  border-radius: var(--radius-lg, 16px);
  text-decoration: none;
  color: inherit;
  transition: all 0.22s ease;
  cursor: pointer;
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-sm, 0 1px 3px rgba(11, 30, 54, 0.05));
}

.mode-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 5px;
  background: var(--subj-phys-accent, #2563EB);
  opacity: 0;
  transition: opacity 0.2s ease;
}

.mode-card:hover {
  border-color: var(--subj-phys-accent, #2563EB);
  transform: translateY(-3px);
  box-shadow: 0 10px 25px rgba(37, 99, 235, 0.12);
}

.mode-card:hover::before {
  opacity: 1;
}

.mode-icon-box {
  width: 56px;
  height: 56px;
  border-radius: 14px;
  background: var(--subj-phys-light, #EFF6FF);
  color: var(--subj-phys-dark, #1E3A8A);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 28px;
  margin-bottom: 16px;
  border: 1px solid var(--subj-phys-border, #BFDBFE);
}

.mode-title {
  font-size: 20px;
  font-weight: 700;
  color: var(--brand-navy-900, #0B1E36);
  margin: 0 0 4px 0;
}

.mode-title-burmese {
  font-size: 14px;
  font-weight: 500;
  color: var(--brand-gold, #C59B27);
  margin: 0 0 10px 0;
}

.mode-desc {
  font-size: 14px;
  line-height: 1.55;
  color: var(--text-secondary, #64748B);
  margin: 0 0 18px 0;
}

.mode-badge-wrap {
  margin-bottom: 12px;
}

.mode-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  font-weight: 700;
  color: var(--subj-phys-dark, #1E3A8A);
  background: var(--subj-phys-light, #EFF6FF);
  padding: 4px 12px;
  border-radius: var(--radius-pill, 9999px);
  border: 1px solid var(--subj-phys-border, #BFDBFE);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.mode-action-btn {
  margin-top: auto;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 18px;
  border-radius: var(--radius-md, 8px);
  background: var(--subj-phys-accent, #2563EB);
  color: #FFFFFF;
  font-size: 13.5px;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: background 0.15s ease;
}

.mode-card:hover .mode-action-btn {
  background: var(--subj-phys-hover, #1D4ED8);
}

/* Physics Chapters Grid */
.phys-chapter-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(290px, 1fr));
  gap: 16px;
  margin-top: 16px;
}

.phys-chapter-card {
  display: flex;
  flex-direction: column;
  padding: 20px;
  background: var(--surface-card, #FFFFFF);
  border: 1px solid var(--border-color, #E2E8F0);
  border-radius: var(--radius-md, 12px);
  text-decoration: none;
  color: inherit;
  transition: all 0.18s ease;
  cursor: pointer;
  min-height: 150px;
}

.phys-chapter-card:hover {
  border-color: var(--subj-phys-accent, #2563EB);
  transform: translateY(-2px);
  box-shadow: 0 6px 18px rgba(37, 99, 235, 0.1);
}

.phys-chapter-card .card-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 8px;
}

.phys-chapter-card .chapter-badge {
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--subj-phys-dark, #1E3A8A);
  background: var(--subj-phys-light, #EFF6FF);
  padding: 3px 10px;
  border-radius: var(--radius-pill, 9999px);
}

.phys-chapter-card .chapter-type-pill {
  font-size: 11.5px;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: var(--radius-pill, 9999px);
  background: #F1F5F9;
  color: #475569;
}

.phys-chapter-card .chapter-name {
  font-size: 16px;
  font-weight: 600;
  color: var(--brand-navy-900, #0B1E36);
  margin: 0 0 8px 0;
  line-height: 1.4;
}

.phys-chapter-card .chapter-preview {
  font-size: 13px;
  color: var(--text-secondary, #64748B);
  margin: 0 0 14px 0;
  line-height: 1.45;
}

.phys-chapter-card .chapter-btn {
  margin-top: auto;
  font-size: 13px;
  font-weight: 600;
  color: var(--subj-phys-accent, #2563EB);
  background: none;
  border: none;
  padding: 0;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 4px;
}

/* Physics 6 Notes Categories Filter Bar */
.notes-filter-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  overflow-x: auto;
  padding-bottom: 8px;
  margin-bottom: 18px;
  -webkit-overflow-scrolling: touch;
}

.notes-filter-pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 7px 16px;
  border-radius: var(--radius-pill, 9999px);
  font-size: 13px;
  font-weight: 600;
  background: var(--surface-card, #FFFFFF);
  color: var(--text-secondary, #64748B);
  border: 1px solid var(--border-color, #E2E8F0);
  cursor: pointer;
  white-space: nowrap;
  transition: all 0.15s ease;
  font-family: inherit;
}

.notes-filter-pill:hover {
  border-color: var(--subj-phys-accent, #2563EB);
  color: var(--subj-phys-dark, #1E3A8A);
}

.notes-filter-pill.active {
  background: var(--subj-phys-accent, #2563EB);
  color: #FFFFFF;
  border-color: var(--subj-phys-accent, #2563EB);
  box-shadow: 0 2px 8px rgba(37, 99, 235, 0.25);
}

/* Physics Practice: 5 Categories Grid */
.phys-category-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 18px;
  margin-top: 20px;
}

.phys-cat-card {
  display: flex;
  flex-direction: column;
  padding: 14px 16px;
  background: var(--surface-card, #FFFFFF);
  border: 1px solid var(--border-color, #E2E8F0);
  border-radius: var(--radius-md, 14px);
  text-decoration: none;
  color: inherit;
  transition: all 0.2s ease;
  cursor: pointer;
  position: relative;
}

.phys-cat-card:hover:not(.card-future-version) {
  border-color: var(--subj-phys-accent, #2563EB);
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(37, 99, 235, 0.12);
}

.phys-cat-card .qtype-header-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  margin-bottom: 8px;
  width: 100%;
}

.phys-cat-card .qtype-label-group {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-width: 0;
}

.phys-cat-card .qtype-icon {
  font-size: 18px;
  line-height: 1;
}

.phys-cat-card .qtype-title {
  font-size: 15px;
  font-weight: 700;
  color: var(--brand-navy-900, #0B1E36);
  margin: 0;
}

.phys-cat-pill {
  display: inline-flex;
  align-items: center;
  padding: 2px 8px;
  border-radius: var(--radius-pill, 9999px);
  font-size: 11px;
  font-weight: 700;
  width: fit-content;
  white-space: nowrap;
}

.cat-tf { background: #FEF3C7; color: #92400E; border: 1px solid #FDE68A; }
.cat-mcq { background: #ECFDF5; color: #065F46; border: 1px solid #A7F3D0; }
.cat-blank { background: #EFF6FF; color: #1E40AF; border: 1px solid #BFDBFE; }
.cat-review { background: #FDF4FF; color: #86198F; border: 1px solid #F0ABFC; }
.cat-structured { background: #FFFBEB; color: #B45309; border: 1.5px dashed #F59E0B; }

.phys-cat-card p, .phys-cat-card .qtype-desc {
  font-size: 12px;
  color: var(--text-secondary, #64748B);
  line-height: 1.4;
  margin: 0 0 12px 0;
}

.phys-cat-card .btn-start {
  margin-top: auto;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 8px 14px;
  background: var(--subj-phys-accent, #2563EB);
  color: #FFFFFF;
  font-size: 12.5px;
  font-weight: 700;
  border-radius: var(--radius-sm, 8px);
  text-decoration: none;
  transition: background 0.15s ease;
  border: none;
  cursor: pointer;
  font-family: inherit;
}

.phys-cat-card:hover:not(.card-future-version) .btn-start {
  background: var(--subj-phys-hover, #1D4ED8);
}

/* Structured Questions: Honest Future-Version Styling */
.card-future-version {
  background: #FCFDFE;
  border: 1.5px dashed #CBD5E1;
  opacity: 0.95;
}

.future-badge {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 11px;
  font-weight: 700;
  color: #B45309;
  background: #FEF3C7;
  padding: 3px 10px;
  border-radius: var(--radius-pill, 9999px);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin-bottom: 10px;
  width: fit-content;
}

.btn-future-version {
  margin-top: auto;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 9px 16px;
  background: #F1F5F9;
  color: #64748B;
  font-size: 12.5px;
  font-weight: 600;
  border-radius: var(--radius-md, 8px);
  border: 1px solid #E2E8F0;
  cursor: pointer;
}

/* Future-Version Interactive Modal / Notice */
.future-notice-banner {
  padding: 14px 18px;
  background: #FFFBEB;
  border: 1px solid #FDE68A;
  border-radius: var(--radius-md, 10px);
  margin-top: 14px;
  font-size: 13px;
  color: #92400E;
  line-height: 1.5;
  display: none;
}

.future-notice-banner.show {
  display: block;
}

/* Notes Reader & Resources */
.notes-reader-container {
  display: flex;
  flex-direction: column;
  gap: 18px;
  margin-top: 16px;
}

.resource-detail-card {
  padding: 22px;
  background: var(--surface-card, #FFFFFF);
  border: 1px solid var(--border-color, #E2E8F0);
  border-radius: var(--radius-lg, 14px);
  box-shadow: var(--shadow-sm, 0 1px 3px rgba(11, 30, 54, 0.05));
}

.resource-card-header {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 12px;
}

.resource-tag {
  font-size: 11.5px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--subj-phys-dark, #1E3A8A);
  background: var(--subj-phys-light, #EFF6FF);
  padding: 3px 10px;
  border-radius: var(--radius-pill, 9999px);
  border: 1px solid var(--subj-phys-border, #BFDBFE);
}

.resource-heading {
  font-size: 17px;
  font-weight: 700;
  color: var(--brand-navy-900, #0B1E36);
  margin: 0;
}

.resource-text {
  font-size: 14px;
  color: var(--text-secondary, #64748B);
  line-height: 1.5;
  margin: 0 0 14px 0;
}

.resource-body {
  font-size: 14.5px;
  line-height: 1.65;
  color: var(--brand-navy-900, #0B1E36);
  background: #F8FAFC;
  padding: 16px;
  border-radius: 8px;
  border: 1px solid #E2E8F0;
  overflow-x: auto;
  margin-bottom: 14px;
}

.resource-image-wrap {
  width: 100%;
  max-width: 600px;
  margin: 12px auto;
  text-align: center;
}

.resource-responsive-image {
  max-width: 100%;
  height: auto;
  border-radius: 8px;
  box-shadow: var(--shadow-sm, 0 1px 4px rgba(0,0,0,0.1));
}

.resource-attachment {
  margin-top: 12px;
}

.resource-download-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 9px 16px;
  border-radius: var(--radius-md, 8px);
  background: var(--subj-phys-light, #EFF6FF);
  color: var(--subj-phys-dark, #1E3A8A);
  font-size: 13px;
  font-weight: 600;
  border: 1px solid var(--subj-phys-border, #BFDBFE);
  text-decoration: none;
  transition: all 0.15s ease;
}

.resource-download-link:hover {
  background: var(--subj-phys-accent, #2563EB);
  color: #FFFFFF;
}

/* Polished Empty & Error States */
.empty-notes-card {
  text-align: center;
  padding: 48px 24px;
  background: var(--surface-card, #FFFFFF);
  border: 1px solid var(--border-color, #E2E8F0);
  border-radius: var(--radius-lg, 16px);
  margin-top: 20px;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.empty-notes-icon {
  font-size: 48px;
  margin-bottom: 16px;
}

.empty-notes-title {
  font-size: 19px;
  font-weight: 700;
  color: var(--brand-navy-900, #0B1E36);
  margin: 0 0 10px 0;
}

.empty-notes-desc {
  font-size: 14px;
  color: var(--text-secondary, #64748B);
  line-height: 1.55;
  margin: 0 0 24px 0;
}

.empty-notes-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
}

.btn-phys-primary {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 20px;
  border-radius: var(--radius-md, 8px);
  background: var(--subj-phys-accent, #2563EB);
  color: #FFFFFF;
  font-size: 13.5px;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: background 0.15s ease;
  font-family: inherit;
}

.btn-phys-primary:hover {
  background: var(--subj-phys-hover, #1D4ED8);
}

.btn-phys-secondary {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 18px;
  border-radius: var(--radius-md, 8px);
  background: #F1F5F9;
  color: #475569;
  font-size: 13.5px;
  font-weight: 600;
  border: 1px solid #E2E8F0;
  cursor: pointer;
  transition: background 0.15s ease;
  font-family: inherit;
}

.btn-phys-secondary:hover {
  background: #E2E8F0;
  color: var(--brand-navy-900, #0B1E36);
}

.notes-loading-state {
  text-align: center;
  padding: 48px;
  color: var(--text-secondary, #64748B);
  font-size: 15px;
}

@media (max-width: 768px) {
  .subject-mode-grid {
    grid-template-columns: 1fr;
  }
  .phys-chapter-grid {
    grid-template-columns: 1fr;
  }
  .phys-category-grid {
    grid-template-columns: 1fr;
  }
  .empty-notes-actions {
    flex-direction: column;
    width: 100%;
  }
  .empty-notes-actions button {
    width: 100%;
    justify-content: center;
  }
}


/* ==========================================================================
   PHYSICS REVIEW QUESTIONS — DIGITAL TEXTBOOK / ACADEMIC STYLING
   Natural, Minimal, Academic, Readable, Calm, Professional, Mobile-friendly
   ========================================================================== */

.phys-textbook-section,
.phys-short-q-section {
  display: flex;
  flex-direction: column;
  gap: 20px;
  margin-top: 16px;
  width: 100%;
  max-width: 900px;
  margin-left: auto;
  margin-right: auto;
  box-sizing: border-box;
}

/* Academic Section Header */
.phys-textbook-header,
.short-q-header {
  background: #FFFFFF;
  border: 1px solid #E2E8F0;
  border-radius: 6px;
  padding: 22px 28px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  box-shadow: 0 1px 2px rgba(15, 23, 42, 0.03);
  box-sizing: border-box;
}

.phys-textbook-kicker,
.short-q-subtitle {
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: #1E40AF;
}

.phys-textbook-title,
.short-q-title {
  font-size: 22px;
  font-weight: 700;
  color: #0F172A;
  margin: 0;
  letter-spacing: -0.01em;
  line-height: 1.3;
}

.phys-textbook-meta {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  font-size: 13px;
  color: #475569;
  margin-top: 2px;
}

.phys-meta-sep {
  color: #CBD5E1;
}

.phys-meta-count,
.short-q-count-badge {
  display: inline-flex;
  align-items: center;
  font-size: 12px;
  font-weight: 600;
  color: #334155;
  background: #F1F5F9;
  border: 1px solid #E2E8F0;
  padding: 2px 10px;
  border-radius: 4px;
  width: fit-content;
}

/* Question List & Items */
.phys-textbook-list-container,
.phys-short-q-list {
  display: flex;
  flex-direction: column;
  gap: 20px;
  width: 100%;
  box-sizing: border-box;
}

.phys-textbook-item,
.phys-short-q-card {
  background: #FFFFFF;
  border: 1px solid #E2E8F0;
  border-radius: 6px;
  padding: 24px 28px;
  box-shadow: 0 1px 2px rgba(15, 23, 42, 0.03);
  display: flex;
  flex-direction: column;
  gap: 12px;
  transition: border-color 0.15s ease;
  box-sizing: border-box;
  width: 100%;
}

.phys-textbook-item:hover,
.phys-short-q-card:hover {
  border-color: #CBD5E1;
}

.phys-q-top,
.phys-sq-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

/* Question Number (Academic style) */
.phys-q-num,
.phys-sq-badge {
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: #1D4ED8;
  background: transparent !important;
  border: none !important;
  padding: 0 !important;
  display: inline-block;
  box-shadow: none !important;
}

/* Question Text */
.phys-q-text,
.phys-sq-question {
  font-size: 16.5px;
  font-weight: 600;
  color: #0F172A;
  line-height: 1.6;
}

.phys-q-text p,
.phys-sq-question p {
  margin: 0 0 10px 0;
}

.phys-q-text p:last-child,
.phys-sq-question p:last-child {
  margin-bottom: 0;
}

.phys-q-sublist,
.phys-sq-subq-list {
  margin-top: 10px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding-left: 4px;
}

.phys-q-subitem,
.phys-sq-subq-item {
  font-size: 15px;
  font-weight: 600;
  color: #1E293B;
  line-height: 1.55;
}

/* Answer Callout (Textbook Style) */
.phys-a-block,
.phys-sq-answer-block {
  background: #F8FAFC;
  border: 1px solid #E2E8F0;
  border-left: 3px solid #2563EB;
  border-radius: 4px;
  padding: 16px 20px;
  margin-top: 4px;
  box-sizing: border-box;
}

.phys-a-label,
.phys-sq-answer-label {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: #1E40AF;
  margin-bottom: 8px;
}

.phys-a-content,
.phys-sq-answer-content {
  font-size: 15px;
  color: #1E293B;
  line-height: 1.65;
}

.phys-a-content p,
.phys-sq-answer-content p {
  margin: 0 0 10px 0;
}

.phys-a-content p:last-child,
.phys-sq-answer-content p:last-child {
  margin-bottom: 0;
}

/* Textbook Numbered List for Applications & Forces */
.phys-textbook-list {
  margin: 8px 0 10px 0;
  padding-left: 22px;
  color: #1E293B;
  font-size: 15px;
  line-height: 1.65;
}

.phys-textbook-list li {
  margin-bottom: 6px;
}

.phys-textbook-list li:last-child {
  margin-bottom: 0;
}

/* Multi-part Answers (i, ii, iii) */
.phys-sq-part {
  display: flex;
  gap: 10px;
  margin-bottom: 14px;
}

.phys-sq-part:last-child {
  margin-bottom: 0;
}

.phys-sq-part-label {
  font-size: 14.5px;
  font-weight: 700;
  color: #1D4ED8;
  flex-shrink: 0;
  padding-top: 1px;
}

.phys-sq-part-body {
  flex-grow: 1;
}

.phys-sq-part-body p {
  margin: 0 0 8px 0;
}

.phys-sq-part-body p:last-child {
  margin-bottom: 0;
}

/* Clean Math Formatting */
.phys-math-lead,
.phys-math-where {
  font-weight: 600;
  color: #334155;
  margin: 6px 0 4px 0 !important;
}

.phys-math-equation {
  display: inline-block;
  font-size: 15.5px;
  color: #0F172A;
  background: #FFFFFF;
  border: 1px solid #CBD5E1;
  border-radius: 6px;
  padding: 4px 12px;
  margin: 4px 0;
  max-width: 100%;
  box-sizing: border-box;
  vertical-align: middle;
}

div.phys-math-equation,
.phys-math-equation.phys-math-block {
  display: block;
  text-align: center;
  overflow-x: auto;
  overflow-y: hidden;
  -webkit-overflow-scrolling: touch;
  padding: 8px 14px;
  margin: 8px 0 10px 0;
  background: #F8FAFC;
  border-color: #CBD5E1;
}

@media (max-width: 600px) {
  .phys-math-equation {
    font-size: 14px;
    padding: 3px 8px;
  }
  div.phys-math-equation,
  .phys-math-equation.phys-math-block {
    padding: 6px 10px;
    font-size: 14px;
  }
}

.phys-math-defs {
  list-style: none;
  padding: 0 0 0 4px;
  margin: 4px 0 10px 0;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.phys-math-defs li {
  font-size: 14px;
  color: #334155;
  line-height: 1.5;
}

.phys-math-defs .var {
  font-weight: 700;
  color: #0F172A;
}

/* ==========================================================================
   COMPARISON TABLE (QUESTION 07)
   Responsive, Clean Academic Two-Column Design
   ========================================================================== */

.phys-comparison-wrapper {
  width: 100%;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  margin: 12px 0 6px 0;
  border: 1px solid #CBD5E1;
  border-radius: 4px;
  background: #FFFFFF;
  box-sizing: border-box;
}

.phys-comparison-table {
  width: 100%;
  min-width: 520px;
  border-collapse: collapse;
  text-align: left;
  font-size: 14.5px;
  line-height: 1.6;
}

.phys-comparison-table th {
  background: #F1F5F9;
  color: #0F172A;
  font-weight: 700;
  font-size: 14px;
  letter-spacing: 0.02em;
  padding: 12px 18px;
  border-bottom: 2px solid #CBD5E1;
  border-right: 1px solid #E2E8F0;
  width: 50%;
  box-sizing: border-box;
}

.phys-comparison-table th:last-child {
  border-right: none;
}

.phys-comparison-table td {
  padding: 14px 18px;
  border-bottom: 1px solid #E2E8F0;
  border-right: 1px solid #E2E8F0;
  color: #1E293B;
  vertical-align: top;
  width: 50%;
  box-sizing: border-box;
}

.phys-comparison-table td:last-child {
  border-right: none;
}

.phys-comparison-table tr:last-child td {
  border-bottom: none;
}

.phys-comparison-table tr:nth-child(even) td {
  background: #FAFAFC;
}

.phys-point-tag {
  font-weight: 700;
  color: #1D4ED8;
  margin-right: 6px;
  display: inline-block;
}

/* Review Questions Navigation Footer */
.review-q-footer {
  margin-top: 24px;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: flex-start;
  padding-top: 16px;
  border-top: 1px solid #E2E8F0;
  width: 100%;
  box-sizing: border-box;
}

.review-q-footer .btn-phys-primary,
.review-q-footer .btn-phys-secondary {
  padding: 9px 16px;
  font-size: 13.5px;
  font-weight: 600;
  border-radius: 4px;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

/* Mobile Responsiveness */
@media (max-width: 640px) {
  .phys-textbook-header,
  .short-q-header {
    padding: 16px 18px;
    border-radius: 6px;
  }
  .phys-textbook-title,
  .short-q-title {
    font-size: 19px;
  }
  .phys-textbook-item,
  .phys-short-q-card {
    padding: 18px 18px;
    border-radius: 6px;
    gap: 10px;
  }
  .phys-q-text,
  .phys-sq-question {
    font-size: 15.5px;
  }
  .phys-a-block,
  .phys-sq-answer-block {
    padding: 14px 16px;
    border-radius: 4px;
  }
  .phys-a-content,
  .phys-sq-answer-content {
    font-size: 14px;
  }
  .phys-comparison-table {
    min-width: 480px;
    font-size: 13.5px;
  }
  .phys-comparison-table th,
  .phys-comparison-table td {
    padding: 10px 14px;
  }
}
/* ==========================================================================
   PHYSICS NOTES: THREE-SECTION ARCHITECTURE
   1. Definitions
   2. Units and Formulae
   3. Diagrams
   ========================================================================== */

/* Three-Section Menu Grid */
.phys-section-menu-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 16px;
  margin-top: 14px;
  margin-bottom: 28px;
}

.phys-section-card {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  padding: 22px 20px;
  background: var(--surface-card, #FFFFFF);
  border: 1.5px solid var(--border-color, #E2E8F0);
  border-radius: 12px;
  text-decoration: none;
  color: inherit;
  transition: all 0.18s ease;
  cursor: pointer;
  position: relative;
  overflow: hidden;
  box-shadow: 0 1px 3px rgba(11, 30, 54, 0.04);
}

.phys-section-card:hover {
  border-color: var(--subj-phys-accent, #2563EB);
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(37, 99, 235, 0.1);
}

.phys-section-card:focus-visible {
  outline: 2px solid var(--subj-phys-accent, #2563EB);
  outline-offset: 2px;
}

.phys-section-card-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  margin-bottom: 14px;
}

.phys-section-icon-box {
  width: 44px;
  height: 44px;
  border-radius: 10px;
  background: var(--subj-phys-light, #EFF6FF);
  color: var(--subj-phys-dark, #1E3A8A);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
}

.phys-section-badge {
  font-size: 11.5px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  padding: 4px 9px;
  border-radius: 6px;
  background: #F1F5F9;
  color: #475569;
  border: 1px solid #E2E8F0;
}

.phys-section-title {
  font-size: 17px;
  font-weight: 700;
  color: var(--brand-navy-900, #0B1E36);
  margin: 0 0 4px 0;
  line-height: 1.35;
}

.phys-section-subtitle-my {
  font-size: 13.5px;
  color: #475569;
  margin: 0 0 8px 0;
  font-family: 'Pyidaungsu', 'Noto Sans Myanmar', sans-serif;
  line-height: 1.4;
}

.phys-section-desc {
  font-size: 13px;
  color: #64748B;
  line-height: 1.5;
  margin: 0 0 16px 0;
  flex-grow: 1;
}

.phys-section-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  font-weight: 600;
  color: var(--subj-phys-accent, #2563EB);
  background: transparent;
  border: none;
  padding: 0;
  cursor: pointer;
  margin-top: auto;
}

.phys-section-card:hover .phys-section-btn {
  color: var(--subj-phys-dark, #1E3A8A);
  text-decoration: underline;
}

/* Dedicated Reading Modes (Definitions, Units & Formulae) */
.phys-reading-container {
  display: flex;
  flex-direction: column;
  gap: 18px;
  margin-bottom: 32px;
}

.phys-reading-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: 12px;
  padding: 18px 22px;
  background: #FFFFFF;
  border: 1px solid #E2E8F0;
  border-radius: 10px;
}

.phys-reading-header-left {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.phys-reading-tag-row {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.phys-reading-ch-tag {
  font-size: 11px;
  font-weight: 700;
  color: var(--subj-phys-accent, #2563EB);
  background: var(--subj-phys-light, #EFF6FF);
  padding: 3px 8px;
  border-radius: 4px;
  text-transform: uppercase;
}

.phys-reading-sec-tag {
  font-size: 11px;
  font-weight: 700;
  color: #334155;
  background: #F1F5F9;
  padding: 3px 8px;
  border-radius: 4px;
  text-transform: uppercase;
}

.phys-reading-title {
  font-size: 20px;
  font-weight: 700;
  color: var(--brand-navy-900, #0B1E36);
  margin: 0;
  line-height: 1.3;
}

.phys-reading-subtitle {
  font-size: 13.5px;
  color: #64748B;
  margin: 0;
}

/* Friendly Placeholder / Coming Soon State */
.phys-notes-placeholder {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: 44px 24px;
  background: #FFFFFF;
  border: 1px solid #E2E8F0;
  border-radius: 12px;
  margin: 12px 0;
}

.phys-notes-placeholder-icon {
  width: 58px;
  height: 58px;
  border-radius: 50%;
  background: #EFF6FF;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 26px;
  margin-bottom: 16px;
}

.phys-notes-placeholder-title {
  font-size: 19px;
  font-weight: 700;
  color: #0F172A;
  margin: 0 0 8px 0;
}

.phys-notes-placeholder-desc {
  font-size: 14.5px;
  color: #475569;
  line-height: 1.6;
  max-width: 560px;
  margin: 0 0 24px 0;
}

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

/* Structured Content Lists & Tables */
.phys-def-card {
  background: #FFFFFF;
  border: 1px solid #E2E8F0;
  border-radius: 8px;
  padding: 18px 22px;
  margin-bottom: 12px;
}

.phys-def-term {
  font-size: 16px;
  font-weight: 700;
  color: #0F172A;
  margin: 0 0 6px 0;
}

.phys-def-body {
  font-size: 14.5px;
  color: #334155;
  line-height: 1.65;
  margin: 0;
}

.phys-table-responsive {
  width: 100%;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  background: #FFFFFF;
  border: 1px solid #E2E8F0;
  border-radius: 8px;
  margin: 14px 0;
}

.phys-formulae-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 14px;
}

.phys-formulae-table th {
  background: #F8FAFC;
  color: #1E293B;
  font-weight: 700;
  padding: 12px 16px;
  border-bottom: 1px solid #CBD5E1;
  font-size: 12.5px;
  letter-spacing: 0.3px;
  text-transform: uppercase;
}

.phys-formulae-table td {
  padding: 12px 16px;
  border-bottom: 1px solid #E2E8F0;
  color: #334155;
  vertical-align: middle;
}

.phys-formulae-table tr:last-child td {
  border-bottom: none;
}

/* Reading Navigation Footer */
.phys-reading-nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  padding: 16px 0;
  margin-top: 12px;
  border-top: 1px solid #E2E8F0;
}

.phys-reading-nav-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  font-size: 13.5px;
  font-weight: 600;
  border-radius: 6px;
  background: #F1F5F9;
  color: #334155;
  border: 1px solid #CBD5E1;
  cursor: pointer;
  transition: all 0.15s ease;
  font-family: inherit;
  text-decoration: none;
}

.phys-reading-nav-btn:hover {
  background: #E2E8F0;
  color: #0F172A;
}

.phys-reading-nav-btn.primary {
  background: var(--subj-phys-accent, #2563EB);
  color: #FFFFFF;
  border-color: var(--subj-phys-accent, #2563EB);
}

.phys-reading-nav-btn.primary:hover {
  background: var(--subj-phys-hover, #1D4ED8);
}

/* ==========================================================================
   PHYSICS DIAGRAMS — FULL-PAGE TEXTBOOK READING STREAM & ZOOM VIEWER
   ========================================================================== */

.phys-diagram-page-stream {
  display: flex;
  flex-direction: column;
  gap: 28px;
  max-width: 840px;
  margin: 16px auto 32px auto;
  width: 100%;
  box-sizing: border-box;
}

.phys-diagram-page-card {
  display: flex;
  flex-direction: column;
  background: #FFFFFF;
  border: 1.5px solid #E2E8F0;
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 2px 8px rgba(11, 30, 54, 0.05);
  transition: border-color 0.18s ease, box-shadow 0.18s ease;
}

.phys-diagram-page-card:hover {
  border-color: var(--subj-phys-accent, #2563EB);
  box-shadow: 0 6px 18px rgba(37, 99, 235, 0.10);
}

.phys-diagram-page-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 18px;
  background: #F8FAFC;
  border-bottom: 1px solid #E2E8F0;
  flex-wrap: wrap;
  gap: 8px;
}

.phys-diagram-page-meta {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.phys-diagram-page-badge {
  font-size: 12px;
  font-weight: 700;
  color: #FFFFFF;
  background: var(--subj-phys-accent, #2563EB);
  padding: 4px 10px;
  border-radius: 6px;
  letter-spacing: 0.3px;
  white-space: nowrap;
}

.phys-diagram-page-topic {
  font-size: 14.5px;
  font-weight: 600;
  color: #0F172A;
}

.phys-diagram-zoom-pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  border-radius: 9999px;
  background: #EFF6FF;
  color: #1D4ED8;
  border: 1px solid #BFDBFE;
  font-size: 12.5px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s ease;
}

.phys-diagram-zoom-pill:hover {
  background: #DBEAFE;
  color: #1E40AF;
  border-color: #93C5FD;
}

.phys-diagram-page-display {
  width: 100%;
  background: #FAFAFA;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 12px;
  box-sizing: border-box;
  cursor: zoom-in;
  position: relative;
}

.phys-diagram-full-page-img {
  width: 100%;
  height: auto;
  max-width: 100%;
  display: block;
  object-fit: contain;
  border-radius: 4px;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.08);
}

/* Diagrams Gallery Grid (Preserved for compatibility) */
.phys-diagram-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 18px;
  margin-top: 14px;
  margin-bottom: 24px;
}

.phys-diagram-card {
  display: flex;
  flex-direction: column;
  background: #FFFFFF;
  border: 1.5px solid #E2E8F0;
  border-radius: 10px;
  overflow: hidden;
  cursor: pointer;
  transition: all 0.18s ease;
  box-shadow: 0 1px 3px rgba(11, 30, 54, 0.04);
}

.phys-diagram-card:hover {
  border-color: var(--subj-phys-accent, #2563EB);
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(37, 99, 235, 0.12);
}

.phys-diagram-card:focus-visible {
  outline: 2px solid var(--subj-phys-accent, #2563EB);
  outline-offset: 2px;
}

.phys-diagram-thumb-wrap {
  width: 100%;
  aspect-ratio: 4 / 3;
  background: #F8FAFC;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
  border-bottom: 1px solid #E2E8F0;
}

.phys-diagram-thumb-img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  transition: transform 0.2s ease;
  padding: 8px;
  box-sizing: border-box;
}

.phys-diagram-card:hover .phys-diagram-thumb-img {
  transform: scale(1.03);
}

.phys-diagram-thumb-overlay {
  position: absolute;
  inset: 0;
  background: rgba(11, 30, 54, 0.35);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transition: opacity 0.18s ease;
}

.phys-diagram-card:hover .phys-diagram-thumb-overlay {
  opacity: 1;
}

.phys-diagram-view-pill {
  padding: 6px 14px;
  border-radius: 9999px;
  background: #FFFFFF;
  color: #0B1E36;
  font-size: 12.5px;
  font-weight: 700;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

.phys-diagram-info {
  padding: 12px 14px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.phys-diagram-number {
  font-size: 11px;
  font-weight: 700;
  color: var(--subj-phys-accent, #2563EB);
  text-transform: uppercase;
  letter-spacing: 0.3px;
}

.phys-diagram-card-title {
  font-size: 14.5px;
  font-weight: 600;
  color: #0F172A;
  margin: 0;
  line-height: 1.35;
}

/* Diagram Viewer Full Screen / Large View */
.phys-diagram-viewer {
  display: flex;
  flex-direction: column;
  background: #FFFFFF;
  border: 1px solid #E2E8F0;
  border-radius: 12px;
  overflow: hidden;
  margin-bottom: 28px;
}

.phys-diagram-viewer-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 14px 20px;
  border-bottom: 1px solid #E2E8F0;
  background: #F8FAFC;
  flex-wrap: wrap;
  gap: 10px;
}

.phys-diagram-viewer-title-group {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.phys-diagram-viewer-badge {
  font-size: 12px;
  font-weight: 700;
  color: #FFFFFF;
  background: var(--subj-phys-accent, #2563EB);
  padding: 3px 8px;
  border-radius: 4px;
}

.phys-diagram-viewer-title {
  font-size: 16px;
  font-weight: 700;
  color: #0B1E36;
  margin: 0;
}

.phys-diagram-viewport {
  position: relative;
  min-height: 480px;
  max-height: 72vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: #0B1E36;
  overflow: hidden;
  user-select: none;
}

.phys-diagram-img-wrap {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
  box-sizing: border-box;
}

.phys-diagram-viewer-img {
  max-width: 100%;
  max-height: 68vh;
  object-fit: contain;
  transition: transform 0.15s ease-out;
  transform-origin: center center;
}

/* Zoom Toolbar */
.phys-zoom-bar {
  position: absolute;
  bottom: 16px;
  right: 16px;
  display: flex;
  align-items: center;
  gap: 4px;
  background: rgba(11, 30, 54, 0.88);
  backdrop-filter: blur(4px);
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 8px;
  padding: 4px 6px;
  z-index: 10;
}

.phys-zoom-btn {
  width: 32px;
  height: 32px;
  border: none;
  background: transparent;
  color: #FFFFFF;
  font-size: 16px;
  font-weight: 700;
  border-radius: 4px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.12s ease;
}

.phys-zoom-btn:hover {
  background: rgba(255, 255, 255, 0.18);
}

.phys-zoom-badge {
  font-size: 12px;
  font-weight: 600;
  color: #E2E8F0;
  padding: 0 6px;
  min-width: 44px;
  text-align: center;
}

/* Viewer Nav Footer */
.phys-diagram-nav-toolbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 18px;
  background: #F8FAFC;
  border-top: 1px solid #E2E8F0;
  flex-wrap: wrap;
  gap: 10px;
}


/* ==========================================================================
   PHYSICS UNITS & FORMULAE TOPIC-BASED TEXTBOOK READING EXPERIENCE
   ========================================================================== */

.phys-formulae-topics-container {
  display: flex;
  flex-direction: column;
  gap: 20px;
  margin-bottom: 24px;
}

.phys-formula-card {
  background: #FFFFFF;
  border: 1px solid #E2E8F0;
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.phys-formula-card:hover {
  border-color: #CBD5E1;
  box-shadow: 0 3px 8px rgba(0, 0, 0, 0.07);
}

.phys-formula-topic-header {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 20px;
  background: #F8FAFC;
  border-bottom: 1px solid #E2E8F0;
}

.phys-topic-badge {
  display: inline-flex;
  align-items: center;
  padding: 3px 9px;
  border-radius: 6px;
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  background: #EFF6FF;
  color: #1D4ED8;
  border: 1px solid #DBEAFE;
  flex-shrink: 0;
}

.phys-formula-topic-title {
  margin: 0;
  font-size: 16px;
  font-weight: 600;
  color: #0F172A;
  line-height: 1.4;
}

.phys-formula-card-body {
  padding: 18px 20px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.phys-formula-lead {
  margin: 0;
  font-size: 14px;
  font-weight: 500;
  color: #334155;
  line-height: 1.5;
}

.phys-formula-math-block {
  padding: 12px 16px;
  background: #F8FAFC;
  border: 1px solid #E2E8F0;
  border-radius: 8px;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  text-align: center;
}

.phys-formula-math-block .katex-display {
  margin: 6px 0;
}

.phys-formula-bullet-list {
  list-style: none;
  padding: 0;
  margin: 4px 0;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.phys-formula-bullet-list li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 14px;
  color: #334155;
  line-height: 1.5;
}

.phys-bullet-symbol {
  color: #2563EB;
  font-weight: bold;
  flex-shrink: 0;
}

.phys-bullet-text {
  flex: 1;
}

.phys-formula-vars-wrap {
  background: #F8FAFC;
  border: 1px solid #E2E8F0;
  border-radius: 8px;
  padding: 12px 16px;
}

.phys-formula-vars-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 6px;
  font-size: 13.5px;
  color: #334155;
}

.phys-formula-vars-list li {
  line-height: 1.5;
}

.phys-formulae-custom-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13.5px;
  text-align: left;
}

.phys-formulae-custom-table th {
  background: #F1F5F9;
  color: #1E293B;
  font-weight: 600;
  padding: 10px 14px;
  border: 1px solid #E2E8F0;
}

.phys-formulae-custom-table td {
  padding: 10px 14px;
  border: 1px solid #E2E8F0;
  color: #334155;
  vertical-align: middle;
}

.phys-truth-table {
  text-align: center;
}

.phys-truth-table th,
.phys-truth-table td {
  text-align: center;
  padding: 8px 10px;
}

.phys-boolean-rules-table td {
  padding: 8px 14px;
  font-size: 14px;
}

.phys-boxed-formula-card {
  border: 2px solid #2563EB;
  border-radius: 8px;
  padding: 12px 16px;
  background: #EFF6FF;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.phys-boxed-formula-label {
  font-size: 12px;
  font-weight: 700;
  color: #1D4ED8;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.phys-boxed-formula-card .phys-formula-math-block {
  background: #FFFFFF;
  border-color: #BFDBFE;
}

.phys-academic-note {
  font-size: 12px;
  color: #64748B;
  background: #F8FAFC;
  padding: 6px 12px;
  border-left: 3px solid #94A3B8;
  border-radius: 0 4px 4px 0;
  margin-top: 4px;
}

@media (max-width: 640px) {
  .phys-formula-topic-header {
    flex-direction: column;
    align-items: flex-start;
    gap: 6px;
    padding: 12px 14px;
  }
  
  .phys-formula-card-body {
    padding: 14px;
  }
  
  .phys-formula-math-block {
    padding: 8px 10px;
  }

  .phys-diagram-page-stream {
    gap: 18px;
    margin-top: 10px;
    margin-bottom: 24px;
  }

  .phys-diagram-page-header {
    padding: 10px 14px;
  }

  .phys-diagram-page-topic {
    font-size: 13.5px;
  }

  .phys-diagram-zoom-pill {
    padding: 5px 12px;
    font-size: 11.5px;
  }

  .phys-diagram-page-display {
    padding: 8px;
  }

  .phys-diagram-grid {
    grid-template-columns: 1fr;
    gap: 14px;
  }

  .phys-diagram-viewport {
    min-height: 320px;
    max-height: 52vh;
  }

  .phys-diagram-viewer-header {
    padding: 10px 14px;
  }

  .phys-diagram-nav-toolbar {
    padding: 10px 12px;
  }
}

.phys-diagram-card-desc {
  font-size: 12px;
  color: #64748B;
  margin: 2px 0 0 0;
  line-height: 1.4;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.phys-diagram-viewer-caption-box {
  padding: 14px 20px;
  background: #F8FAFC;
  border-top: 1px solid #E2E8F0;
}

.phys-diagram-viewer-caption-label {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: #64748B;
  margin-bottom: 4px;
}

.phys-diagram-viewer-caption-text {
  font-size: 14px;
  color: #1E293B;
  line-height: 1.5;
  margin: 0;
}




/* ========================================================================= */
/* MMM STUDY — PHASE 3.2 PHYSICS ACADEMIC DESIGN BENCHMARK SPECIFICATION     */
/* ========================================================================= */

/* Surface & Body Hierarchy */
body {
  background-color: var(--subj-phys-bg, #F8FAFC) !important;
  color: var(--subj-phys-text-primary, #0F172A);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, "Myanmar Text", "Padauk", sans-serif;
  line-height: 1.5;
}

/* Headings & Descriptions */
#physics-heading {
  font-size: 24px;
  font-weight: 700;
  color: var(--subj-phys-text-primary, #0F172A);
  letter-spacing: -0.01em;
  margin: 0 0 6px 0;
}

#physics-desc {
  font-size: 14.5px;
  color: var(--subj-phys-text-secondary, #475569);
  line-height: 1.55;
  margin: 0;
}

/* Curriculum Navigation & Breadcrumbs */
.curriculum-nav-bar {
  display: flex;
  align-items: center;
  gap: 12px;
  background: var(--subj-phys-surface, #FFFFFF);
  border: 1px solid #E2E8F0;
  border-radius: 10px;
  padding: 10px 16px;
  margin-bottom: 20px;
  box-shadow: 0 1px 2px rgba(15, 23, 42, 0.04);
}

.curriculum-back-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: #F1F5F9;
  color: var(--subj-phys-text-primary, #0F172A);
  border: 1px solid #E2E8F0;
  border-radius: 8px;
  padding: 6px 14px;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s ease;
}

.curriculum-back-btn:hover {
  background: #E2E8F0;
  color: #0F172A;
  transform: translateX(-2px);
  box-shadow: none;
}

.curriculum-breadcrumbs {
  font-size: 13px;
  color: var(--subj-phys-text-secondary, #475569);
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 6px;
}

.curriculum-breadcrumbs a {
  color: var(--subj-phys-accent, #0D9488);
  text-decoration: none;
  font-weight: 500;
}

.curriculum-breadcrumbs a:hover {
  text-decoration: underline;
}

.curriculum-breadcrumbs strong {
  color: var(--subj-phys-text-primary, #0F172A);
  font-weight: 600;
}

/* Screen 1: Dual-Track Academic Layout */
.phys-dual-track {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 22px;
  margin-top: 18px;
  margin-bottom: 32px;
}

.phys-dual-track .mode-card {
  display: flex;
  flex-direction: column;
  padding: 24px;
  background: var(--subj-phys-surface, #FFFFFF);
  border: 1px solid #E2E8F0;
  border-radius: 12px;
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  box-shadow: 0 1px 3px rgba(15, 23, 42, 0.04);
  position: relative;
  overflow: hidden;
}

.phys-dual-track .mode-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--subj-phys-accent, #0D9488);
  opacity: 0;
  transition: opacity 0.2s ease;
}

.phys-dual-track .mode-card:hover {
  border-color: #99F6E4;
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(13, 148, 136, 0.08);
}

.phys-dual-track .mode-card:hover::before {
  opacity: 1;
}

.phys-dual-track .mode-card:focus-visible {
  outline: 2px solid var(--subj-phys-accent, #0D9488);
  outline-offset: 2px;
}

.mode-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
}

.mode-icon-box {
  width: 46px;
  height: 46px;
  border-radius: 10px;
  background: var(--subj-phys-light, #F0FDFA);
  color: var(--subj-phys-accent, #0D9488);
  border: 1px solid var(--subj-phys-border, #CCFBF1);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  transition: transform 0.2s ease;
}

.mode-card:hover .mode-icon-box {
  transform: scale(1.05);
}

.mode-badge-wrap .mode-badge {
  font-size: 11.5px;
  font-weight: 600;
  padding: 3px 10px;
  border-radius: 6px;
  background: #F1F5F9;
  color: #334155;
  border: 1px solid #E2E8F0;
  letter-spacing: 0.02em;
}

.mode-card-body {
  margin-top: 16px;
  flex-grow: 1;
}

.mode-title {
  font-size: 19px;
  font-weight: 700;
  color: var(--subj-phys-text-primary, #0F172A);
  margin: 0;
  line-height: 1.35;
}

.mode-title-burmese {
  font-size: 14.5px;
  font-weight: 500;
  color: var(--subj-phys-text-secondary, #475569);
  margin: 4px 0 0 0;
  line-height: 1.6;
}

.mode-desc {
  font-size: 13.5px;
  color: var(--subj-phys-text-secondary, #475569);
  line-height: 1.6;
  margin: 8px 0 0 0;
}

.mode-card-footer {
  margin-top: 20px;
  padding-top: 16px;
  border-top: 1px solid #F1F5F9;
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  gap: 12px;
}

.mode-meta-indicator {
  font-size: 12px;
  color: var(--subj-phys-text-muted, #64748B);
  font-weight: 500;
}

.mode-action-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--subj-phys-accent, #0D9488);
  color: #FFFFFF;
  border: none;
  padding: 8px 16px;
  border-radius: 8px;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s ease;
}

.mode-card:hover .mode-action-btn {
  background: var(--subj-phys-hover, #0F766E);
  box-shadow: 0 4px 12px rgba(13, 148, 136, 0.25);
}

/* Chapter Grids (Notes & Practice) */
.phys-chapter-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-top: 18px;
  margin-bottom: 32px;
}

.phys-chapter-card {
  display: flex;
  flex-direction: column;
  padding: 16px 18px;
  background: var(--subj-phys-surface, #FFFFFF);
  border: 1px solid #E2E8F0;
  border-radius: 10px;
  cursor: pointer;
  transition: all 0.18s ease;
  box-shadow: 0 1px 2px rgba(15, 23, 42, 0.03);
  position: relative;
  min-height: 128px;
}

.phys-chapter-card:hover {
  border-color: #99F6E4;
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(15, 23, 42, 0.06);
}

.phys-chapter-card:focus-visible {
  outline: 2px solid var(--subj-phys-accent, #0D9488);
  outline-offset: 2px;
}

.phys-chapter-card .card-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 10px;
}

.phys-chapter-card .chapter-badge {
  font-size: 11.5px;
  font-weight: 700;
  color: #334155;
  background: #F1F5F9;
  border: 1px solid #E2E8F0;
  padding: 2px 7px;
  border-radius: 5px;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  letter-spacing: 0.03em;
}

.phys-chapter-card .chapter-type-pill {
  font-size: 11px;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 999px;
  background: var(--subj-phys-light, #F0FDFA);
  color: var(--subj-phys-accent, #0D9488);
  border: 1px solid var(--subj-phys-border, #CCFBF1);
}

.phys-chapter-card .chapter-name {
  font-size: 15px;
  font-weight: 600;
  color: var(--subj-phys-text-primary, #0F172A);
  margin: 0;
  line-height: 1.4;
  flex-grow: 1;
}

.card-bottom-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 12px;
  padding-top: 10px;
  border-top: 1px solid #F8FAFC;
  gap: 8px;
}

.chapter-sub-meta {
  font-size: 11.5px;
  color: var(--subj-phys-text-muted, #64748B);
}

.chapter-btn {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 12.5px;
  font-weight: 600;
  color: var(--subj-phys-accent, #0D9488);
  background: none;
  border: none;
  padding: 0;
  cursor: pointer;
  transition: transform 0.15s ease;
}

.phys-chapter-card:hover .chapter-btn {
  transform: translateX(2px);
  color: var(--subj-phys-hover, #0F766E);
}

/* Three-Section Notes Hub */
.phys-section-menu-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-top: 18px;
  margin-bottom: 32px;
}

.phys-section-card {
  display: flex;
  flex-direction: column;
  padding: 22px 20px;
  background: var(--subj-phys-surface, #FFFFFF);
  border: 1px solid #E2E8F0;
  border-radius: 12px;
  cursor: pointer;
  transition: all 0.18s ease;
  box-shadow: 0 1px 3px rgba(15, 23, 42, 0.04);
}

.phys-section-card:hover {
  border-color: #99F6E4;
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(13, 148, 136, 0.08);
}

.phys-section-card:focus-visible {
  outline: 2px solid var(--subj-phys-accent, #0D9488);
  outline-offset: 2px;
}

.phys-section-card-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 14px;
}

.phys-section-icon-box {
  width: 42px;
  height: 42px;
  border-radius: 10px;
  background: var(--subj-phys-light, #F0FDFA);
  color: var(--subj-phys-accent, #0D9488);
  border: 1px solid var(--subj-phys-border, #CCFBF1);
  display: flex;
  align-items: center;
  justify-content: center;
}

.phys-section-badge {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  padding: 3px 8px;
  border-radius: 6px;
  background: #F1F5F9;
  color: #475569;
  border: 1px solid #E2E8F0;
}

.phys-section-title {
  font-size: 17px;
  font-weight: 700;
  color: var(--subj-phys-text-primary, #0F172A);
  margin: 0 0 4px 0;
  line-height: 1.35;
}

.phys-section-subtitle-my {
  font-size: 13.5px;
  font-weight: 500;
  color: var(--subj-phys-text-secondary, #475569);
  line-height: 1.6;
  margin-bottom: 8px;
}

.phys-section-desc {
  font-size: 13px;
  color: var(--subj-phys-text-muted, #64748B);
  line-height: 1.6;
  flex-grow: 1;
  margin: 0 0 16px 0;
}

.phys-section-btn {
  display: inline-flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  background: #F8FAFC;
  color: var(--subj-phys-text-primary, #0F172A);
  border: 1px solid #E2E8F0;
  padding: 8px 14px;
  border-radius: 8px;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s ease;
}

.phys-section-card:hover .phys-section-btn {
  background: var(--subj-phys-accent, #0D9488);
  color: #FFFFFF;
  border-color: var(--subj-phys-accent, #0D9488);
}

/* Question-Type Selection Grid */
.phys-category-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 18px;
  margin-top: 18px;
  margin-bottom: 32px;
}

.phys-cat-card {
  display: flex;
  flex-direction: column;
  padding: 18px 20px;
  background: var(--subj-phys-surface, #FFFFFF);
  border: 1px solid #E2E8F0;
  border-radius: 10px;
  cursor: pointer;
  transition: all 0.18s ease;
  box-shadow: 0 1px 3px rgba(15, 23, 42, 0.03);
}

.phys-cat-card:hover:not(.card-future-version) {
  border-color: #99F6E4;
  transform: translateY(-2px);
  box-shadow: 0 6px 18px rgba(13, 148, 136, 0.08);
}

.phys-cat-card:focus-visible {
  outline: 2px solid var(--subj-phys-accent, #0D9488);
  outline-offset: 2px;
}

.qtype-header-row {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 10px;
}

.qtype-label-group {
  display: flex;
  align-items: center;
  gap: 10px;
}

.qtype-icon-box {
  width: 38px;
  height: 38px;
  border-radius: 8px;
  background: var(--subj-phys-light, #F0FDFA);
  color: var(--subj-phys-accent, #0D9488);
  border: 1px solid var(--subj-phys-border, #CCFBF1);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.qtype-title {
  font-size: 15.5px;
  font-weight: 700;
  color: var(--subj-phys-text-primary, #0F172A);
  margin: 0;
  line-height: 1.3;
}

.qtype-subtitle {
  font-size: 12px;
  color: var(--subj-phys-text-muted, #64748B);
  font-weight: 500;
  display: block;
  margin-top: 1px;
}

.phys-cat-pill {
  font-size: 11.5px;
  font-weight: 600;
  padding: 3px 9px;
  border-radius: 999px;
  white-space: nowrap;
}

.phys-cat-pill.cat-tf,
.phys-cat-pill.cat-mcq,
.phys-cat-pill.cat-blank {
  background: var(--subj-phys-light, #F0FDFA);
  color: var(--subj-phys-accent, #0D9488);
  border: 1px solid var(--subj-phys-border, #CCFBF1);
}

.phys-cat-pill.cat-review {
  background: #EFF6FF;
  color: #1D4ED8;
  border: 1px solid #DBEAFE;
}

.future-badge {
  font-size: 11.5px;
  font-weight: 600;
  padding: 3px 9px;
  border-radius: 999px;
  background: #F8FAFC;
  color: var(--subj-phys-text-muted, #64748B);
  border: 1px solid #E2E8F0;
  white-space: nowrap;
}

.qtype-desc {
  font-size: 13px;
  color: var(--subj-phys-text-secondary, #475569);
  line-height: 1.6;
  flex-grow: 1;
  margin: 0 0 16px 0;
}

.btn-start {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  background: var(--subj-phys-accent, #0D9488);
  color: #FFFFFF;
  text-decoration: none;
  padding: 8px 16px;
  border-radius: 8px;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s ease;
  border: none;
  width: 100%;
  box-sizing: border-box;
}

.btn-start:hover {
  background: var(--subj-phys-hover, #0F766E);
  box-shadow: 0 4px 12px rgba(13, 148, 136, 0.25);
}

.btn-future-version {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  background: #F8FAFC;
  color: #475569;
  border: 1px solid #E2E8F0;
  padding: 8px 14px;
  border-radius: 8px;
  font-size: 12.5px;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.15s ease;
  width: 100%;
}

.btn-future-version:hover {
  background: #F1F5F9;
  color: #0F172A;
}

.future-notice-banner {
  display: none;
  margin-top: 12px;
  padding: 10px 14px;
  background: #F8FAFC;
  border: 1px solid #E2E8F0;
  border-radius: 8px;
  font-size: 12px;
  color: #475569;
  line-height: 1.5;
}

/* Notes Reading View & Formula Layout */
.phys-reading-container {
  max-width: 900px;
  margin: 0 auto 40px auto;
}

.phys-reading-header {
  background: var(--subj-phys-surface, #FFFFFF);
  border: 1px solid #E2E8F0;
  border-radius: 12px;
  padding: 20px 24px;
  margin-bottom: 20px;
  box-shadow: 0 1px 2px rgba(15, 23, 42, 0.03);
}

.phys-reading-tag-row {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 8px;
}

.phys-reading-ch-tag {
  font-size: 11.5px;
  font-weight: 700;
  color: #334155;
  background: #F1F5F9;
  border: 1px solid #E2E8F0;
  padding: 2px 8px;
  border-radius: 5px;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
}

.phys-reading-sec-tag {
  font-size: 11.5px;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 999px;
  background: var(--subj-phys-light, #F0FDFA);
  color: var(--subj-phys-accent, #0D9488);
  border: 1px solid var(--subj-phys-border, #CCFBF1);
}

.phys-reading-title {
  font-size: 22px;
  font-weight: 700;
  color: var(--subj-phys-text-primary, #0F172A);
  margin: 0 0 4px 0;
}

.phys-reading-subtitle {
  font-size: 14px;
  color: var(--subj-phys-text-secondary, #475569);
  margin: 0;
}

.phys-def-card,
.phys-boxed-formula-card {
  background: var(--subj-phys-surface, #FFFFFF);
  border: 1px solid #E2E8F0;
  border-radius: 10px;
  padding: 18px 20px;
  margin-bottom: 14px;
  box-shadow: 0 1px 2px rgba(15, 23, 42, 0.03);
}

.phys-def-term {
  font-size: 15.5px;
  font-weight: 700;
  color: var(--subj-phys-text-primary, #0F172A);
  margin: 0 0 8px 0;
}

.phys-def-body {
  font-size: 14px;
  color: var(--subj-phys-text-secondary, #475569);
  line-height: 1.6;
}

/* KaTeX Formula Overflow Protection */
.katex-display {
  overflow-x: auto !important;
  overflow-y: hidden !important;
  padding: 6px 0 !important;
  margin: 8px 0 !important;
  max-width: 100% !important;
  -webkit-overflow-scrolling: touch;
}

.phys-formula-math-block {
  max-width: 100%;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

/* Diagrams Viewer Stage */
.phys-viewer-container {
  background: var(--subj-phys-surface, #FFFFFF);
  border: 1px solid #E2E8F0;
  border-radius: 12px;
  padding: 16px;
  box-shadow: 0 1px 3px rgba(15, 23, 42, 0.04);
}

.chem-viewer-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-bottom: 12px;
  border-bottom: 1px solid #E2E8F0;
  margin-bottom: 14px;
}

.chem-viewer-btn,
.chem-zoom-btn {
  background: #F1F5F9;
  color: #0F172A;
  border: 1px solid #CBD5E1;
  border-radius: 6px;
  padding: 6px 12px;
  font-size: 12.5px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s ease;
}

.chem-viewer-btn:hover,
.chem-zoom-btn:hover {
  background: #E2E8F0;
}

.chem-zoom-badge {
  font-size: 12px;
  font-weight: 600;
  padding: 4px 8px;
  background: #F8FAFC;
  border: 1px solid #E2E8F0;
  border-radius: 4px;
}

/* ========================================================================= */
/* RESPONSIVE SPECIFICATIONS (1280px, 768px, 412px, 375px, 360px)           */
/* ========================================================================= */

@media (max-width: 1024px) {
  .phys-chapter-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .phys-dual-track {
    grid-template-columns: 1fr;
    gap: 16px;
  }
  .phys-chapter-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
  }
  .phys-section-menu-grid {
    grid-template-columns: 1fr;
    gap: 14px;
  }
  .phys-category-grid {
    grid-template-columns: 1fr;
    gap: 14px;
  }
}

@media (max-width: 480px) {
  .phys-chapter-grid {
    grid-template-columns: 1fr;
    gap: 10px;
  }
  .phys-dual-track .mode-card {
    padding: 18px 16px;
  }
  .mode-title {
    font-size: 17px;
  }
  .mode-desc {
    font-size: 13px;
  }
  .curriculum-nav-bar {
    padding: 8px 12px;
  }
  .chem-viewer-toolbar {
    flex-wrap: wrap;
    gap: 8px;
  }
}

@media (max-width: 360px) {
  .phys-chapter-card {
    padding: 14px;
  }
  .phys-cat-card {
    padding: 14px;
  }
  .btn-start {
    font-size: 12px;
    padding: 7px 12px;
  }
}



/* ========================================================================= */
/* Non-blocking in-situ loading placeholder & error states (Phase 3.2.1)     */
/* ========================================================================= */

.phys-loading-placeholder {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 240px;
  background: var(--subj-phys-surface, #FFFFFF);
  border: 1px solid var(--subj-phys-border, #E2E8F0);
  border-radius: var(--subj-phys-radius-lg, 12px);
  margin-top: 18px;
  padding: 36px 20px;
  text-align: center;
  box-shadow: 0 1px 2px rgba(15, 23, 42, 0.03);
}

.phys-loading-spinner-wrap {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
}

.phys-loading-spinner {
  width: 32px;
  height: 32px;
  border: 3px solid #F1F5F9;
  border-top-color: var(--subj-phys-accent, #0D9488);
  border-radius: 50%;
  animation: physSpin 0.75s linear infinite;
}

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

.phys-loading-text {
  font-size: 15px;
  font-weight: 600;
  color: var(--subj-phys-text-primary, #0F172A);
  margin: 0;
}

.phys-loading-subtext {
  font-size: 13px;
  color: var(--subj-phys-text-secondary, #475569);
  margin: 0;
}

.phys-error-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 240px;
  background: var(--subj-phys-surface, #FFFFFF);
  border: 1px solid #FECACA;
  border-radius: var(--subj-phys-radius-lg, 12px);
  margin-top: 18px;
  padding: 32px 24px;
  text-align: center;
  box-shadow: 0 1px 3px rgba(239, 68, 68, 0.05);
}

.phys-error-icon-box {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: #FEF2F2;
  color: #DC2626;
  border: 1px solid #FCA5A5;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 12px;
}

.phys-error-title {
  font-size: 16.5px;
  font-weight: 700;
  color: #0F172A;
  margin: 0 0 6px 0;
}

.phys-error-desc {
  font-size: 13.5px;
  color: #475569;
  line-height: 1.55;
  max-width: 440px;
  margin: 0 0 18px 0;
}

.btn-phys-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  background: var(--subj-phys-accent, #0D9488);
  color: #FFFFFF;
  border: none;
  padding: 9px 18px;
  border-radius: 8px;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s ease;
}

.btn-phys-primary:hover {
  background: var(--subj-phys-hover, #0F766E);
  box-shadow: 0 4px 12px rgba(13, 148, 136, 0.25);
}



/* ========================================================================= */
/* Phase 3.3 Reusable Academic Accessibility & Typography Refinements        */
/* ========================================================================= */

/* Focus Visible Rings for Keyboard Accessibility (WCAG 2.1 AA) */
.mode-card:focus-visible,
.phys-chapter-card:focus-visible,
.phys-section-card:focus-visible,
.phys-cat-card:focus-visible,
.curriculum-back-btn:focus-visible,
.mode-action-btn:focus-visible,
.btn-start:focus-visible,
.btn-phys-primary:focus-visible,
.btn-future-version:focus-visible,
.chem-viewer-btn:focus-visible,
.chem-zoom-btn:focus-visible,
.phys-reading-nav-btn:focus-visible {
  outline: 2px solid var(--subj-phys-accent, #0D9488) !important;
  outline-offset: 2px !important;
}

/* Reduced Motion Compatibility */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
  .phys-loading-spinner {
    animation: none !important;
    border-top-color: var(--subj-phys-accent, #0D9488);
  }
}

/* Burmese Font Rendering & Diacritic Collision Safeguard */
[lang="my"],
.mode-title-burmese,
.phys-section-subtitle-my,
.phys-loading-subtext {
  font-family: "Noto Sans Myanmar", "Padauk", "Pyidaungsu", -apple-system, sans-serif !important;
  line-height: 1.65 !important;
}

/* Minimum Touch Target Sizes (44px) for Mobile Controls */
@media (max-width: 768px) {
  .mode-action-btn,
  .btn-start,
  .curriculum-back-btn,
  .btn-phys-primary,
  .phys-section-btn {
    min-height: 44px;
    box-sizing: border-box;
  }
}