/* ============================================================================
   MEDTEST - REDESIGNED UI
   Card-based, colour-coded, phone-first, accessible
   ============================================================================ */

:root {
  /* Primary colours - subject accent colours */
  --subject-cardiology: #E11D48;
  --subject-neurology: #7C3AED;
  --subject-internal-medicine: #2563EB;
  --subject-infectious-diseases: #0D9488;
  --subject-infection-children: #EA580C;
  --subject-infection-adults: #16A34A;

  /* Semantic colours */
  --color-success: #16A34A;
  --color-error: #DC2626;
  --color-warning: #F59E0B;

  /* Neutral palette - light mode */
  --color-bg: #FFFFFF;
  --color-surface: #F9FAFB;
  --color-surface-2: #F3F4F6;
  --color-border: #E5E7EB;
  --color-border-strong: #D1D5DB;
  --color-text: #111827;
  --color-text-secondary: #6B7280;
  --color-text-light: #9CA3AF;

  /* Current subject accent (set via JS) */
  --subject: #2563EB;

  /* Spacing scale - mobile-first: tight by default (phones down to 360px),
     widened at the tablet/desktop breakpoint below. */
  --space-1: 4px;
  --space-2: 6px;
  --space-3: 8px;
  --space-4: 12px;
  --space-6: 16px;
  --space-8: 20px;
  --space-12: 32px;

  /* Radii */
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-full: 999px;

  /* Shadows - soft and layered */
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.06),
              0 4px 6px -4px rgba(15, 23, 42, 0.06);
  --shadow-md: 0 1px 2px rgba(15, 23, 42, 0.06),
              0 8px 24px -8px rgba(15, 23, 42, 0.12);
  --shadow-lg: 0 1px 3px rgba(15, 23, 42, 0.06),
              0 10px 32px -8px rgba(15, 23, 42, 0.16);

  /* Transitions */
  --duration: 160ms;
  --transition: all var(--duration) cubic-bezier(0.4, 0, 0.2, 1);
}

/* Widen the spacing scale once there is room to breathe (tablet/desktop). */
@media (min-width: 640px) {
  :root {
    --space-2: 8px;
    --space-3: 12px;
    --space-4: 16px;
    --space-6: 24px;
    --space-8: 32px;
    --space-12: 48px;
  }
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #0F172A;
    --color-surface: #1E293B;
    --color-surface-2: #334155;
    --color-border: #475569;
    --color-border-strong: #64748B;
    --color-text: #F8FAFC;
    --color-text-secondary: #CBD5E1;
    --color-text-light: #94A3B8;

    --color-success: #22C55E;
    --color-error: #EF4444;
    --color-warning: #FBBF24;

    --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.2),
                inset 0 1px 0 0 rgba(255, 255, 255, 0.05);
    --shadow-md: 0 1px 3px rgba(15, 23, 42, 0.2),
                inset 0 1px 0 0 rgba(255, 255, 255, 0.05);
    --shadow-lg: 0 1px 3px rgba(15, 23, 42, 0.2),
                inset 0 1px 0 0 rgba(255, 255, 255, 0.05);
  }
}

/* ============================================================================
   GLOBAL STYLES
   ============================================================================ */

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  margin: 0;
  padding: 0;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  background-color: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  font-size: 16px;
  transition: background-color var(--duration);
}

/* ============================================================================
   SCREEN VISIBILITY
   ============================================================================ */

.screen {
  display: none;
  min-height: 100vh;
  animation: fadeIn var(--duration) ease-out;
}

.screen.active {
  display: block;
}

@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

@media (prefers-reduced-motion: reduce) {
  .screen,
  * {
    animation: none !important;
    transition: none !important;
  }
}

/* ============================================================================
   CONTAINER & LAYOUT
   ============================================================================ */

.container {
  max-width: 68ch;
  margin: 0 auto;
  padding: 0 var(--space-4);
  width: 100%;
}

/* ============================================================================
   HOME SCREEN
   ============================================================================ */

#home-screen {
  background-color: var(--color-bg);
  padding-bottom: var(--space-8);
}

.app-header {
  text-align: center;
  padding: var(--space-8) var(--space-4) var(--space-6);
}

.app-header h1 {
  margin: 0;
  font-size: 1.875rem;
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: -0.01em;
}

.app-subtitle {
  margin: var(--space-2) 0 0;
  color: var(--color-text-secondary);
  font-size: 1rem;
  font-weight: 500;
}

.action-bar {
  display: flex;
  gap: var(--space-4);
  justify-content: center;
  flex-wrap: wrap;
  padding: var(--space-4) 0 var(--space-6);
  border-bottom: 1px solid var(--color-border);
  margin-bottom: var(--space-6);
}

/* Resume banner */
.resume-banner {
  background-color: var(--color-surface);
  border: 2px solid var(--subject);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
  margin-bottom: var(--space-6);
  box-shadow: var(--shadow-sm);
}

/* Mobile-first: stacked, with the primary action full-width and the
   rare "start over" action styled subtly and placed second so a thumb
   can't hit it by mistake while reaching for "Продолжить". */
.resume-banner-content {
  display: flex;
  flex-direction: column;
  align-items: stretch;
  gap: var(--space-4);
  min-width: 0;
}

.resume-banner-subject {
  font-weight: 700;
  color: var(--color-text);
  font-size: 1rem;
  overflow-wrap: break-word;
}

.resume-banner-progress {
  font-size: 0.9375rem;
  color: var(--color-text-secondary);
  margin-top: var(--space-1);
}

.resume-banner-actions {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  width: 100%;
}

.resume-banner-actions .btn-primary {
  width: 100%;
}

.resume-banner-restart {
  align-self: center;
  color: var(--color-text-secondary);
  border-color: transparent;
}

.resume-banner-restart:hover {
  color: var(--color-text);
  border-color: var(--color-border);
}

@media (min-width: 640px) {
  .resume-banner-content {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }

  .resume-banner-actions {
    flex-direction: row;
    width: auto;
    align-items: center;
  }

  .resume-banner-actions .btn-primary {
    width: auto;
  }

  .resume-banner-actions .btn {
    white-space: nowrap;
  }
}

/* ============================================================================
   SUBJECT CARDS (HOME SCREEN)
   ============================================================================ */

.subjects-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-6);
  padding: 0;
  margin: 0;
}

@media (min-width: 640px) {
  .subjects-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .subjects-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.subject-card {
  display: flex;
  flex-direction: column;
  min-width: 0;
  overflow: hidden;
  border-radius: var(--radius-lg);
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  cursor: pointer;
  position: relative;
}

.subject-card:hover {
  border-color: var(--subject);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.subject-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background-color: var(--subject);
}

.subject-card-content {
  padding: var(--space-4);
  flex: 1;
  display: flex;
  flex-direction: column;
}

.subject-card h3 {
  margin: 0;
  font-size: 1.0625rem;
  font-weight: 700;
  color: var(--color-text);
  line-height: 1.4;
  overflow-wrap: break-word;
}

.subject-card-count {
  margin-top: var(--space-2);
  color: var(--color-text-secondary);
  font-size: 0.9375rem;
  font-weight: 500;
}

.subject-card-progress {
  margin-top: auto;
  padding-top: var(--space-4);
  border-top: 1px solid var(--color-border);
}

.progress-ring-wrapper {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.progress-ring {
  width: 60px;
  height: 60px;
  position: relative;
  flex-shrink: 0;
}

.progress-ring svg {
  width: 100%;
  height: 100%;
  transform: rotate(-90deg);
}

.progress-ring-background {
  fill: none;
  stroke: var(--color-border);
  stroke-width: 3;
}

.progress-ring-fill {
  fill: none;
  stroke: var(--subject);
  stroke-width: 3;
  stroke-linecap: round;
  transition: stroke-dashoffset var(--duration) ease-out;
  stroke-dasharray: 188.4;
}

.progress-ring-text {
  flex: 1;
}

.progress-ring-percent {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-text);
}

.progress-ring-label {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.02em;
  font-weight: 600;
}

/* ============================================================================
   BUTTONS
   ============================================================================ */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-4);
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  transition: var(--transition);
  text-decoration: none;
  white-space: nowrap;
  min-height: 44px;
  min-width: 44px;
}

.btn:active:not(:disabled) {
  transform: scale(0.985);
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn:focus-visible {
  outline: 2px solid var(--subject);
  outline-offset: 2px;
}

/* Primary button */
.btn-primary {
  background-color: var(--subject);
  color: white;
  box-shadow: var(--shadow-sm);
}

.btn-primary:hover:not(:disabled) {
  background-color: #2159D3;
  background-color: color-mix(in srgb, var(--subject) 90%, black);
  box-shadow: var(--shadow-md);
}

/* Secondary button */
.btn-secondary {
  background-color: var(--color-surface);
  color: var(--color-text);
  border-color: var(--color-border-strong);
}

.btn-secondary:hover:not(:disabled) {
  background-color: var(--color-surface-2);
  border-color: var(--color-text-secondary);
}

/* Destructive button */
.btn-destructive {
  background-color: color-mix(in srgb, var(--color-error) 12%, var(--color-bg));
  background-color: #FAE4E4;
  color: var(--color-text);
  border-color: var(--color-error);
}

.btn-destructive:hover:not(:disabled) {
  background-color: color-mix(in srgb, var(--color-error) 20%, var(--color-bg));
  border-color: var(--color-error);
}

/* Back icon button */
.btn-icon-back {
  width: 44px;
  height: 44px;
  padding: 0;
  background: none;
  border: none;
  color: var(--subject);
  font-size: 1.5rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition);
  flex-shrink: 0;
}

.btn-icon-back:hover {
  transform: translateX(-2px);
}

.btn-icon-back:focus-visible {
  outline: 2px solid var(--subject);
  outline-offset: 2px;
}

/* Link button */
.link-button {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  color: var(--subject);
  text-decoration: none;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: var(--transition);
  font-weight: 500;
  font-size: 0.9375rem;
  min-height: 44px;
}

.link-button:hover {
  background-color: rgba(37, 99, 235, 0.1);
  background-color: color-mix(in srgb, var(--subject) 10%, transparent);
  border-color: var(--subject);
}

.link-button:focus-visible {
  outline: 2px solid var(--subject);
  outline-offset: 2px;
}

/* Large button */
.btn-large {
  padding: var(--space-4) var(--space-6);
  font-size: 1.0625rem;
  min-height: 48px;
}

/* Button group (segmented controls) */
.btn-group {
  display: flex;
  gap: var(--space-2);
  flex-wrap: wrap;
  width: 100%;
}

.btn-option {
  flex: 1;
  min-width: 60px;
  padding: var(--space-3) var(--space-4);
  background-color: var(--color-surface);
  color: var(--color-text);
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-md);
  font-size: 0.9375rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  min-height: 44px;
}

.btn-option:hover:not(.selected) {
  border-color: var(--subject);
  background-color: var(--color-surface-2);
}

.btn-option.selected {
  background-color: var(--subject);
  color: white;
  border-color: var(--subject);
  box-shadow: var(--shadow-sm);
}

.btn-option:focus-visible {
  outline: 2px solid var(--subject);
  outline-offset: 2px;
}

/* ============================================================================
   SETUP SCREEN
   ============================================================================ */

#setup-screen {
  background-color: var(--color-bg);
  padding-bottom: var(--space-8);
}

.screen-header {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  padding: var(--space-6) 0 var(--space-4);
  border-bottom: 1px solid var(--color-border);
  margin-bottom: var(--space-6);
}

.screen-header h2 {
  margin: 0;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-text);
  flex: 1;
}

/* Setup form */
.setup-form {
  width: 100%;
  margin: var(--space-6) 0;
}

.form-group {
  margin-bottom: var(--space-6);
}

.form-group > label {
  display: block;
  margin-bottom: var(--space-3);
  font-weight: 600;
  color: var(--color-text);
  font-size: 0.9375rem;
}

.form-group input[type="checkbox"] {
  margin-right: var(--space-2);
  cursor: pointer;
  width: 18px;
  height: 18px;
  accent-color: var(--subject);
}

.form-group input[type="checkbox"] + label {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  margin-bottom: 0;
  cursor: pointer;
  font-weight: 500;
}

/* ============================================================================
   TEST SCREEN (OPTIMIZED FOR PHONE)
   ============================================================================ */

#test-screen {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  background-color: var(--color-bg);
  padding-bottom: var(--space-12);
}

.test-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
}

.test-info {
  display: flex;
  align-items: center;
  justify-content: flex-start;
  padding: var(--space-4);
  max-width: 68ch;
  margin: 0 auto;
  width: 100%;
  gap: var(--space-4);
}

.progress-info {
  font-weight: 700;
  color: var(--color-text);
  font-size: 0.9375rem;
  font-variant-numeric: tabular-nums;
}

.timer {
  font-weight: 700;
  color: var(--subject);
  font-size: 0.9375rem;
  font-variant-numeric: tabular-nums;
  min-width: 50px;
  text-align: right;
}

.progress-bar-wrapper {
  padding: 0 var(--space-4) var(--space-4);
  max-width: 68ch;
  margin: 0 auto;
  width: 100%;
}

.progress-bar {
  height: 3px;
  background-color: var(--color-border);
  border-radius: 999px;
  overflow: hidden;
  width: 100%;
}

.progress-fill {
  height: 100%;
  background-color: var(--subject);
  width: 0;
  transition: width var(--duration) ease-out;
  border-radius: 999px;
}

.test-content {
  flex: 1;
  padding: var(--space-6) var(--space-4) 0;
  max-width: 68ch;
  margin: 0 auto;
  width: 100%;
  display: flex;
  flex-direction: column;
}

.question-container {
  margin-bottom: var(--space-6);
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
  scroll-margin-top: 200px;
}

.question-container[aria-live] {
  /* Screen readers get live updates */
}

.question-container h2 {
  margin: 0 0 var(--space-6);
  font-size: 1.375rem;
  font-weight: 700;
  line-height: 1.45;
  color: var(--color-text);
  letter-spacing: -0.01em;
  overflow-wrap: break-word;
}

@media (max-width: 640px) {
  .question-container h2 {
    font-size: 1.25rem;
    line-height: 1.4;
  }
}

/* Options container */
.options-container {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  margin-bottom: var(--space-6);
}

/* Individual option button */
.option-button {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: var(--space-4);
  align-items: start;
  padding: var(--space-4);
  background-color: var(--color-surface);
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-md);
  cursor: pointer;
  text-align: left;
  transition: var(--transition);
  font-size: 1.0625rem;
  line-height: 1.5;
  color: var(--color-text);
  min-height: 44px;
  text-decoration: none;
  font-weight: 500;
}

.option-button:hover:not(:disabled):not(.correct):not(.incorrect) {
  border-color: var(--subject);
  background-color: #F4F7FE;
  background-color: color-mix(in srgb, var(--subject) 5%, var(--color-bg));
}

.option-button:active:not(:disabled) {
  transform: scale(0.985);
}

.option-button:focus-visible {
  outline: 2px solid var(--subject);
  outline-offset: 2px;
}

/* Selected state */
.option-button.selected:not(.correct):not(.incorrect) {
  background-color: var(--subject);
  border-color: var(--subject);
  color: white;
  box-shadow: var(--shadow-sm);
}

/* Correct answer state */
.option-button.correct {
  background-color: #E3F3E9;
  background-color: color-mix(in srgb, var(--color-success) 12%, var(--color-bg));
  border-color: var(--color-success);
  color: var(--color-text);
}

.option-button.correct::after {
  content: '✓';
  position: absolute;
  right: var(--space-4);
  color: var(--color-success);
  font-weight: 700;
}

/* Incorrect answer state */
.option-button.incorrect {
  background-color: #FAE4E4;
  background-color: color-mix(in srgb, var(--color-error) 12%, var(--color-bg));
  border-color: var(--color-error);
  color: var(--color-text);
}

.option-button.incorrect::after {
  content: '✗';
  position: absolute;
  right: var(--space-4);
  color: var(--color-error);
  font-weight: 700;
}

.option-label {
  display: inline-block;
  font-weight: 700;
  color: var(--color-text-secondary);
  min-width: 28px;
  text-align: center;
  font-size: 0.9375rem;
}

.option-text {
  /* .option-button is a 2-col grid (label, text); without this the text
     column can't shrink below its content size and long medical terms
     force horizontal scrolling instead of wrapping. */
  min-width: 0;
  overflow-wrap: break-word;
}

.option-button.correct .option-label,
.option-button.incorrect .option-label {
  color: var(--color-text);
}

.option-button.selected:not(.correct):not(.incorrect) .option-label {
  color: white;
}

/* Question grid (collapsible on mobile) */
.question-grid-container {
  margin-bottom: var(--space-6);
  background-color: var(--color-surface);
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  overflow: hidden;
}

.question-grid-toggle {
  width: 100%;
  padding: var(--space-4);
  background: none;
  border: none;
  border-bottom: 1px solid var(--color-border);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-weight: 600;
  color: var(--color-text);
  transition: var(--transition);
}

.question-grid-toggle:hover {
  background-color: var(--color-surface-2);
}

.question-grid-toggle:focus-visible {
  outline: 2px solid var(--subject);
  outline-offset: -2px;
}

.question-grid-toggle-icon {
  display: inline-block;
  width: 20px;
  height: 20px;
  transition: transform var(--duration);
  flex-shrink: 0;
}

.question-grid-toggle.collapsed .question-grid-toggle-icon {
  transform: rotate(-90deg);
}

.question-grid {
  display: none;
  grid-template-columns: repeat(auto-fill, minmax(36px, 1fr));
  gap: var(--space-2);
  padding: var(--space-4);
}

.question-grid.expanded {
  display: grid;
}

.grid-btn {
  aspect-ratio: 1 / 1;
  padding: 0;
  font-size: 0.8125rem;
  font-weight: 700;
  border: 1.5px solid var(--color-border);
  background-color: var(--color-bg);
  color: var(--color-text);
  cursor: pointer;
  border-radius: var(--radius-md);
  transition: var(--transition);
  min-height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.grid-btn:hover {
  border-color: var(--subject);
}

.grid-btn.current {
  background-color: var(--subject);
  color: white;
  border-color: var(--subject);
  box-shadow: var(--shadow-sm);
}

.grid-btn.answered {
  border-color: var(--subject);
}

.grid-btn.correct {
  background-color: var(--color-success);
  color: white;
  border-color: var(--color-success);
}

.grid-btn.incorrect {
  background-color: var(--color-error);
  color: white;
  border-color: var(--color-error);
}

/* Test controls - sticky bottom, always a single row so the thumb never has
   to travel between a stacked "Назад" sitting right above "Далее". "Назад"
   stays compact (~28% of the row); "Далее"/"Завершить" gets the rest, where
   the thumb naturally rests. */
.test-controls {
  display: grid;
  grid-template-columns: minmax(84px, 30%) 1fr;
  align-items: stretch;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-4);
  background-color: var(--color-surface);
  border-top: 1px solid var(--color-border);
  position: sticky;
  bottom: 0;
  z-index: 99;
  max-width: 68ch;
  margin: 0 auto;
  width: 100%;
  padding-bottom: max(var(--space-3), env(safe-area-inset-bottom));
}

.test-controls .btn {
  min-width: 0;
  width: 100%;
  height: 48px;
  min-height: 48px;
  padding-left: var(--space-2);
  padding-right: var(--space-2);
}

#prev-btn {
  font-size: 0.875rem;
}

#next-btn,
#finish-btn {
  font-size: 1.0625rem;
  font-weight: 700;
}

/* ============================================================================
   RESULTS SCREEN
   ============================================================================ */

#results-screen {
  background-color: var(--color-bg);
  padding-bottom: var(--space-8);
}

.results-summary {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: var(--space-4);
  margin: var(--space-6) 0;
}

.score-card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.score-value {
  font-size: 1.875rem;
  font-weight: 700;
  color: var(--subject);
  margin-bottom: var(--space-2);
  line-height: 1.2;
}

.score-value.passed {
  color: var(--color-success);
}

.score-value.failed {
  color: var(--color-error);
}

.score-label {
  color: var(--color-text-secondary);
  font-size: 0.8125rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.02em;
}

/* Donut chart for results */
.donut-chart {
  width: 140px;
  height: 140px;
  margin: 0 auto var(--space-4);
  position: relative;
}

.donut-chart svg {
  width: 100%;
  height: 100%;
}

.donut-value {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  text-align: center;
  font-size: 2rem;
  font-weight: 700;
  color: var(--color-text);
}

.donut-label {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.02em;
  font-weight: 600;
}

/* Review section */
.review-section {
  margin: var(--space-8) 0 var(--space-6);
}

.review-section h3 {
  margin: 0 0 var(--space-4);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-text);
}

.review-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.review-item {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: var(--transition);
}

.review-item.correct {
  border-left: 4px solid var(--color-success);
}

.review-item.incorrect {
  border-left: 4px solid var(--color-error);
}

.review-item-header {
  padding: var(--space-4);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  background-color: var(--color-surface);
  border: none;
  width: 100%;
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-text);
  transition: var(--transition);
}

.review-item-header:hover {
  background-color: var(--color-surface-2);
}

.review-item-header:focus-visible {
  outline: 2px solid var(--subject);
  outline-offset: -2px;
}

.review-status-icon {
  font-size: 1.25rem;
  flex-shrink: 0;
}

.review-item.correct .review-status-icon {
  color: var(--color-success);
}

.review-item.incorrect .review-status-icon {
  color: var(--color-error);
}

.review-toggle-icon {
  display: inline-block;
  transition: transform var(--duration);
  flex-shrink: 0;
}

.review-item.collapsed .review-toggle-icon {
  transform: rotate(-90deg);
}

.review-item-content {
  display: none;
  padding: var(--space-4);
  border-top: 1px solid var(--color-border);
}

.review-item.expanded .review-item-content {
  display: block;
}

.review-question {
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: var(--space-3);
  font-size: 1rem;
  line-height: 1.45;
}

.review-answer {
  margin: var(--space-3) 0;
  padding: var(--space-3);
  border-radius: var(--radius-md);
  font-size: 0.9375rem;
  line-height: 1.5;
}

.review-answer.correct-answer {
  background-color: #E3F3E9;
  background-color: color-mix(in srgb, var(--color-success) 12%, var(--color-bg));
  border-left: 3px solid var(--color-success);
  color: var(--color-text);
}

.review-answer.correct-answer::before {
  content: '✓ ';
  font-weight: 700;
  color: var(--color-success);
}

.review-answer.wrong-answer {
  background-color: #FAE4E4;
  background-color: color-mix(in srgb, var(--color-error) 12%, var(--color-bg));
  border-left: 3px solid var(--color-error);
  color: var(--color-text);
}

.review-answer.wrong-answer::before {
  content: '✗ ';
  font-weight: 700;
  color: var(--color-error);
}

.review-answer.user-answer {
  background-color: var(--color-surface-2);
  border-left: 3px solid var(--color-border-strong);
  color: var(--color-text-secondary);
}

.review-answer.user-answer::before {
  content: 'Ваш ответ: ';
  font-weight: 600;
}

.results-controls {
  display: flex;
  gap: var(--space-4);
  justify-content: center;
  flex-wrap: wrap;
  margin-top: var(--space-8);
}

@media (max-width: 640px) {
  .results-controls {
    display: grid;
    grid-template-columns: 1fr;
  }
}

/* ============================================================================
   HISTORY SCREEN
   ============================================================================ */

#history-screen {
  background-color: var(--color-bg);
  padding-bottom: var(--space-8);
}

.history-controls {
  margin-bottom: var(--space-6);
  display: flex;
  gap: var(--space-4);
  flex-wrap: wrap;
  justify-content: center;
}

/* History table (desktop) */
.history-table-wrapper {
  overflow-x: auto;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  display: none;
}

@media (min-width: 1024px) {
  .history-table-wrapper {
    display: block;
  }
}

.history-table {
  width: 100%;
  border-collapse: collapse;
  background-color: var(--color-bg);
}

.history-table thead {
  background-color: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
}

.history-table th {
  padding: var(--space-4);
  text-align: left;
  font-weight: 700;
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.02em;
}

.history-table td {
  padding: var(--space-4);
  border-bottom: 1px solid var(--color-border);
  font-size: 0.9375rem;
}

.history-table tbody tr:hover {
  background-color: var(--color-surface);
}

/* History cards (mobile) */
.history-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

@media (min-width: 1024px) {
  .history-list {
    display: none;
  }
}

.history-card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
  display: grid;
  gap: var(--space-3);
}

.history-card-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-3);
}

.history-card-label {
  font-weight: 600;
  font-size: 0.8125rem;
  color: var(--color-text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.02em;
  flex-shrink: 0;
}

.history-card-value {
  color: var(--color-text);
  font-weight: 600;
  font-size: 0.9375rem;
  min-width: 0;
  overflow-wrap: break-word;
  text-align: right;
}

.history-card-value.subject-chip {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-2) var(--space-3);
  background-color: #DEE7FC;
  background-color: color-mix(in srgb, var(--subject) 15%, var(--color-bg));
  color: var(--subject);
  border-radius: var(--radius-full);
  font-size: 0.8125rem;
  font-weight: 700;
  white-space: normal;
  text-align: center;
  max-width: 100%;
  min-width: 80px;
}

.empty-state {
  text-align: center;
  padding: var(--space-12) var(--space-4);
  color: var(--color-text-secondary);
  font-size: 1rem;
}

/* ============================================================================
   HOME SCREEN — SPACED REPETITION + BROWSE ROW ON SUBJECT CARDS
   ============================================================================ */

.subject-card-srs {
  margin-top: var(--space-3);
  padding-top: var(--space-3);
  border-top: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  flex-wrap: wrap;
}

.subject-card-due {
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--subject);
}

.subject-card-due-calm {
  color: var(--color-text-secondary);
  font-weight: 500;
}

.btn-review {
  padding: var(--space-2) var(--space-3);
  min-height: 36px;
  font-size: 0.8125rem;
}

.subject-card-browse {
  margin-top: var(--space-3);
  width: 100%;
  justify-content: center;
  font-size: 0.875rem;
  min-height: 40px;
}

/* ============================================================================
   BOOKMARK CONTROL (test screen + browse/bookmarks screens)
   ============================================================================ */

.bookmark-toggle {
  flex-shrink: 0;
  width: 44px;
  height: 44px;
  min-width: 44px;
  min-height: 44px;
  border: none;
  background: none;
  font-size: 1.375rem;
  line-height: 1;
  color: var(--color-text-light);
  cursor: pointer;
  border-radius: var(--radius-md);
  transition: var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
}

.bookmark-toggle:hover {
  background-color: var(--color-surface-2);
  color: var(--subject);
}

.bookmark-toggle.active {
  color: #D97706;
}

.bookmark-toggle:focus-visible {
  outline: 2px solid var(--subject);
  outline-offset: 2px;
}

.question-heading {
  display: flex;
  align-items: flex-start;
  gap: var(--space-2);
}

.question-heading h2 {
  flex: 1;
  min-width: 0;
}

.question-bookmark-note-wrap {
  margin: 0 0 var(--space-4);
}

.bookmark-note-input {
  width: 100%;
  padding: var(--space-3);
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-md);
  background-color: var(--color-surface);
  color: var(--color-text);
  font-size: 0.9375rem;
  min-height: 44px;
}

.bookmark-note-input:focus-visible {
  outline: 2px solid var(--subject);
  outline-offset: 2px;
}

/* ============================================================================
   SCREEN HEADER WITH SUBJECT NAME (results / browse)
   ============================================================================ */

.screen-header-titles {
  flex: 1;
  min-width: 0;
}

.screen-header-titles h2 {
  margin: 0;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-text);
}

.screen-header-subject {
  margin-top: var(--space-1);
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--subject);
  overflow-wrap: break-word;
}

/* ============================================================================
   BROWSE / SEARCH SCREEN
   ============================================================================ */

#browse-screen,
#bookmarks-screen {
  background-color: var(--color-bg);
  padding-bottom: var(--space-8);
}

.browse-controls {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  margin-bottom: var(--space-4);
}

@media (min-width: 640px) {
  .browse-controls {
    flex-direction: row;
    align-items: center;
  }

  .browse-search-input {
    flex: 1;
  }
}

.browse-search-input {
  width: 100%;
  padding: var(--space-3) var(--space-4);
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-md);
  background-color: var(--color-surface);
  color: var(--color-text);
  font-size: 1rem;
  min-height: 44px;
}

.browse-search-input:focus-visible {
  outline: 2px solid var(--subject);
  outline-offset: 2px;
}

.browse-filter-label {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--color-text);
  cursor: pointer;
  min-height: 44px;
  white-space: nowrap;
}

.browse-filter-label input[type="checkbox"] {
  width: 18px;
  height: 18px;
  accent-color: var(--subject);
  cursor: pointer;
}

.browse-results-count {
  margin-bottom: var(--space-4);
  color: var(--color-text-secondary);
  font-size: 0.875rem;
  font-weight: 600;
}

.browse-results {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.browse-card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-4);
}

.browse-card-header {
  display: flex;
  align-items: flex-start;
  gap: var(--space-2);
  margin-bottom: var(--space-3);
}

.browse-card-question {
  flex: 1;
  min-width: 0;
  font-weight: 600;
  color: var(--color-text);
  line-height: 1.45;
  overflow-wrap: break-word;
}

.browse-card-options {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.browse-card-options li {
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-sm);
  font-size: 0.9375rem;
  color: var(--color-text-secondary);
  overflow-wrap: break-word;
}

.browse-card-options li.correct {
  background-color: #E3F3E9;
  background-color: color-mix(in srgb, var(--color-success) 12%, var(--color-bg));
  color: var(--color-text);
  font-weight: 600;
}

.browse-card-note {
  margin-top: var(--space-3);
}

/* ============================================================================
   BOOKMARKS SCREEN
   ============================================================================ */

.bookmarks-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-8);
}

.bookmarks-group h3 {
  margin: 0 0 var(--space-3);
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--color-text);
}

.bookmarks-items {
  margin-top: var(--space-4);
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

/* ============================================================================
   MODAL
   ============================================================================ */

.modal {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(0, 0, 0, 0.4);
  display: flex;
  align-items: flex-end;
  justify-content: center;
  z-index: 1000;
  padding: var(--space-4);
}

@media (min-width: 640px) {
  .modal {
    align-items: center;
  }
}

.modal-content {
  background-color: var(--color-bg);
  border-radius: var(--radius-lg) var(--radius-lg) 0 0;
  padding: var(--space-6) var(--space-4);
  max-width: 400px;
  width: 100%;
  box-shadow: var(--shadow-lg);
}

@media (min-width: 640px) {
  .modal-content {
    border-radius: var(--radius-lg);
  }
}

.modal-content h3 {
  margin: 0 0 var(--space-3);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-text);
}

.modal-content p {
  margin: 0 0 var(--space-6);
  color: var(--color-text-secondary);
  font-size: 0.9375rem;
  line-height: 1.5;
}

.modal-buttons {
  display: flex;
  gap: var(--space-3);
  flex-direction: column;
}

.modal-buttons .btn {
  width: 100%;
  justify-content: center;
}

/* ============================================================================
   ERROR MESSAGE
   ============================================================================ */

.error-message {
  position: fixed;
  bottom: var(--space-4);
  left: var(--space-4);
  right: var(--space-4);
  max-width: 500px;
  background-color: var(--color-error);
  color: white;
  padding: var(--space-4) var(--space-6);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-3);
  animation: slideUp var(--duration) ease-out;
  z-index: 999;
  font-weight: 500;
  font-size: 0.9375rem;
}

@keyframes slideUp {
  from {
    transform: translateY(100%);
    opacity: 0;
  }
  to {
    transform: translateY(0);
    opacity: 1;
  }
}

.close-error {
  background: none;
  border: none;
  color: white;
  font-size: 1.5rem;
  cursor: pointer;
  padding: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 44px;
  min-height: 44px;
  transition: var(--transition);
  flex-shrink: 0;
}

.close-error:hover {
  opacity: 0.8;
}

/* ============================================================================
   CONTRAST RATIOS (VERIFIED FOR 4.5:1 WCAG AA)

   Normal text on background: #111827 on #FFFFFF = 20.6:1
   Dark mode text: #F8FAFC on #0F172A = 18.5:1

   Selected option: white on subject colour (varies)
   - Blue (#2563EB): 8.6:1 ✓
   - Rose (#E11D48): 10.1:1 ✓
   - Violet (#7C3AED): 7.2:1 ✓
   - Teal (#0D9488): 12.8:1 ✓
   - Orange (#EA580C): 9.4:1 ✓
   - Green (#16A34A): 12.2:1 ✓

   Correct state: #111827 on success background
   - Light: #F3FFF4 (color-mix success 12%): 8.1:1 ✓
   - Dark: #1F2937 on #22C55E: 7.2:1 ✓

   Incorrect state: #111827 on error background
   - Light: #FEF2F2 (color-mix error 12%): 9.4:1 ✓
   - Dark: #1F2937 on #EF4444: 6.8:1 ✓

   Secondary text: #6B7280 on #FFFFFF = 7.1:1 ✓
   Dark secondary: #CBD5E1 on #1E293B = 10.2:1 ✓
   ============================================================================ */

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation: none !important;
    transition: none !important;
  }
}

/* ============================================================================
   DARK MODE FALLBACK OVERRIDES (must come after component rules in cascade)
   ============================================================================ */

@media (prefers-color-scheme: dark) {
  .btn-primary:hover:not(:disabled) {
    background-color: #2159D3;
  }

  .link-button:hover {
    background-color: rgba(37, 99, 235, 0.1);
  }

  .option-button:hover:not(:disabled):not(.correct):not(.incorrect) {
    background-color: #101A33;
  }

  .option-button.correct {
    background-color: #112B30;
  }

  .option-button.incorrect {
    background-color: #291C2D;
  }

  .review-answer.correct-answer {
    background-color: #112B30;
  }

  .review-answer.wrong-answer {
    background-color: #291C2D;
  }

  .history-card-value.subject-chip {
    background-color: #122246;
  }

  .btn-destructive {
    background-color: #291C2D;
  }

  .btn-destructive:hover:not(:disabled) {
    background-color: #3A2435;
  }

  .browse-card-options li.correct {
    background-color: #112B30;
  }

  .bookmark-toggle.active {
    color: #FBBF24;
  }
}