/* =============================================================
   Learnfyra — Solve Page Styles v2.0
   File: frontend/css/solve.css
   Extends: styles.css (CSS custom properties reused)
   Audience: Students aged 6–16 — large, readable, energetic
   ============================================================= */

/* ---------------------------------------------------------------
   Screen-reader utility
   --------------------------------------------------------------- */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* ---------------------------------------------------------------
   Mode Selection Screen — big, inviting choice cards
   --------------------------------------------------------------- */
.mode-selection {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-4);
  margin-top: var(--space-4);
}

.mode-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-3);
  padding: 2.25rem var(--space-6);
  border-radius: var(--radius-lg);
  border: 2.5px solid transparent;
  cursor: pointer;
  font-family: var(--font);
  text-align: center;
  transition:
    transform var(--transition-md),
    box-shadow var(--transition-md),
    background-color var(--transition),
    border-color var(--transition);
  position: relative;
  overflow: hidden;
}

/* Subtle texture overlay on mode buttons */
.mode-btn::before {
  content: '';
  position: absolute;
  inset: 0;
  background: repeating-linear-gradient(
    45deg,
    transparent,
    transparent 8px,
    rgb(255 255 255 / 0.05) 8px,
    rgb(255 255 255 / 0.05) 9px
  );
  pointer-events: none;
}

.mode-btn:hover {
  transform: translateY(-4px) scale(1.01);
  box-shadow: var(--shadow-hover);
}

.mode-btn:active {
  transform: scale(0.98);
}

.mode-btn--timed {
  background: linear-gradient(145deg, var(--color-sky) 0%, var(--color-sky-dark) 100%);
  color: #fff;
  box-shadow: var(--shadow-btn);
}

.mode-btn--timed:hover {
  background: linear-gradient(145deg, #2563EB 0%, #1E40AF 100%);
  box-shadow: 0 12px 28px rgb(59 130 246 / 0.45);
}

.mode-btn--untimed {
  background: var(--color-white);
  color: var(--color-ink);
  border-color: var(--color-cloud);
  box-shadow: var(--shadow-sm);
}

.mode-btn--untimed:hover {
  background: var(--color-sky-soft);
  border-color: var(--color-sky);
}

.mode-btn__icon {
  font-size: 2.5rem;
  line-height: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 3.5rem;
  height: 3.5rem;
  border-radius: var(--radius-md);
  background: rgb(255 255 255 / 0.2);
}

.mode-btn--untimed .mode-btn__icon {
  background: var(--color-sky-soft);
}

.mode-btn__label {
  display: block;
  font-family: var(--font-display);
  font-size: 1.2rem;
  font-weight: 800;
  letter-spacing: -0.01em;
}

.mode-btn__desc {
  display: block;
  font-size: 0.875rem;
  font-weight: 600;
  opacity: 0.85;
}

/* ---------------------------------------------------------------
   Timer Bar — Prominent, changes color as urgency increases
   --------------------------------------------------------------- */
.timer-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--color-sky-soft);
  border: 2px solid rgb(59 130 246 / 0.25);
  border-radius: var(--radius-md);
  padding: var(--space-3) var(--space-5);
  margin-bottom: var(--space-5);
  transition: background-color var(--transition-md), border-color var(--transition-md);
}

.timer-bar--warning {
  background: var(--color-sun-soft);
  border-color: rgb(251 191 36 / 0.40);
}

.timer-bar--urgent {
  background: var(--color-error-bg);
  border-color: var(--color-error-border);
}

.timer-label {
  font-size: 0.8rem;
  font-weight: 800;
  color: var(--color-sky-dark);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.timer-bar--warning .timer-label {
  color: var(--color-sun-dark);
}

.timer-bar--urgent .timer-label {
  color: var(--color-error);
}

.timer-display {
  font-family: var(--font-display);
  font-size: 2rem;
  font-weight: 800;
  color: var(--color-sky-dark);
  letter-spacing: 0.04em;
  transition: color var(--transition-md);
  /* Monospace digits so they don't shift */
  font-variant-numeric: tabular-nums;
}

.timer-display--warning {
  color: var(--color-sun-dark);
}

.timer-display--urgent {
  color: var(--color-error);
  animation: timerPulse 0.9s ease-in-out infinite;
}

@keyframes timerPulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50%       { opacity: 0.7; transform: scale(0.97); }
}

/* ---------------------------------------------------------------
   Question Cards — Large, airy, kid-friendly
   --------------------------------------------------------------- */
.question-card {
  background: var(--color-white);
  border: 2px solid var(--color-cloud);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  padding: var(--space-6) 1.75rem;
  margin-bottom: var(--space-4);
  animation: fadeRise 300ms ease both;
  transition: border-color var(--transition), box-shadow var(--transition);
  position: relative;
}

.question-card:focus-within {
  border-color: var(--color-sky);
  box-shadow: 0 0 0 4px rgb(59 130 246 / 0.10), var(--shadow-sm);
}

/* Colorful question number accent strip */
.question-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-sky) 0%, var(--color-berry) 100%);
  border-radius: var(--radius-lg) var(--radius-lg) 0 0;
  opacity: 0;
  transition: opacity var(--transition);
}

.question-card:focus-within::before {
  opacity: 1;
}

.question-header {
  display: flex;
  align-items: flex-start;
  gap: var(--space-4);
  margin-bottom: var(--space-4);
  flex-wrap: wrap;
}

.question-badge {
  flex-shrink: 0;
  width: 2.25rem;
  height: 2.25rem;
  background: linear-gradient(135deg, var(--color-sky) 0%, var(--color-berry) 100%);
  color: #fff;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-display);
  font-size: 0.9rem;
  font-weight: 800;
  box-shadow: 0 2px 8px rgb(59 130 246 / 0.30);
}

.question-text {
  flex: 1;
  font-size: 1.0625rem;
  font-weight: 600;
  color: var(--color-ink);
  line-height: 1.6;
  /* Larger text for readability — kids audience */
}

.question-points {
  flex-shrink: 0;
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-sky-dark);
  background: var(--color-sky-soft);
  border: 1.5px solid rgb(59 130 246 / 0.25);
  border-radius: var(--radius-pill);
  padding: 0.2rem 0.65rem;
  align-self: flex-start;
}

.question-input-area {
  padding-left: 3.25rem;
}

/* ---------------------------------------------------------------
   Radio / Option Groups — Touch-friendly large targets
   --------------------------------------------------------------- */
.question-options {
  border: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.option-label {
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
  cursor: pointer;
  font-size: 1rem;
  font-weight: 500;
  color: var(--color-ink);
  padding: 0.75rem var(--space-4);
  border-radius: var(--radius-md);
  border: 2px solid var(--color-cloud);
  background: var(--surface-soft);
  transition:
    background-color var(--transition),
    border-color var(--transition),
    transform 100ms ease;
  user-select: none;
  min-height: 48px; /* touch target */
}

.option-label:hover {
  background: var(--color-sky-soft);
  border-color: var(--color-sky);
  transform: translateX(3px);
}

/* Highlight selected option */
.option-label:has(.option-radio:checked) {
  background: var(--color-sky-soft);
  border-color: var(--color-sky);
  font-weight: 700;
}

.option-radio {
  position: absolute;
  width: 1px;
  height: 1px;
  opacity: 0;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
}

.option-custom {
  flex-shrink: 0;
  width: 1.25rem;
  height: 1.25rem;
  border: 2px solid var(--color-cloud-dark);
  border-radius: 50%;
  background: var(--color-white);
  display: flex;
  align-items: center;
  justify-content: center;
  transition:
    background-color var(--transition),
    border-color var(--transition),
    transform 120ms ease;
}

.option-radio:checked + .option-custom {
  background: var(--color-sky);
  border-color: var(--color-sky);
  transform: scale(1.1);
}

.option-radio:checked + .option-custom::after {
  content: '';
  display: block;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: #fff;
}

.option-radio:focus-visible + .option-custom {
  outline: 3px solid var(--color-sky);
  outline-offset: 2px;
}

.option-radio:checked ~ .option-text {
  font-weight: 700;
}

/* ---------------------------------------------------------------
   Text Inputs in Questions — Notebook-rule style
   --------------------------------------------------------------- */
.fill-input {
  max-width: 28rem;
}

.short-answer-input,
.work-area {
  resize: vertical;
  width: 100%;
  /* Ruled-line background for student work areas */
  background-image: linear-gradient(
    transparent calc(100% - 1px),
    rgb(59 130 246 / 0.12) calc(100% - 1px)
  );
  background-size: 100% 2.25rem;
}

.final-answer-label {
  margin-top: var(--space-3);
  margin-bottom: var(--space-2);
}

.final-answer-input {
  max-width: 28rem;
}

/* ---------------------------------------------------------------
   Matching Questions
   --------------------------------------------------------------- */
.matching-wrap {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.matching-row {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  padding: var(--space-3) var(--space-4);
  background: var(--surface-soft);
  border: 2px solid var(--color-cloud);
  border-radius: var(--radius-md);
  transition: border-color var(--transition);
}

.matching-row:focus-within {
  border-color: var(--color-sky);
  background: var(--color-sky-soft);
}

.matching-left {
  flex: 0 0 40%;
  font-weight: 700;
  color: var(--color-ink);
  font-size: 1rem;
}

/* Arrow connector */
.matching-left::after {
  content: ' →';
  color: var(--color-sky);
  font-weight: 800;
}

.matching-right-input {
  flex: 1;
  max-width: 20rem;
}

/* ---------------------------------------------------------------
   Submit / Solve Actions
   --------------------------------------------------------------- */
.solve-actions {
  justify-content: flex-end;
  padding: var(--space-4) 0 var(--space-8);
}

/* Large submit button — full visual weight */
.solve-actions .btn--primary {
  padding: 0.9375rem 2.5rem;
  font-size: 1.0625rem;
  border-radius: var(--radius-lg);
}

/* ---------------------------------------------------------------
   Results — Score Header (prominent celebration)
   --------------------------------------------------------------- */
.results-score-header {
  display: flex;
  align-items: center;
  gap: var(--space-6);
  padding: var(--space-8) var(--space-8);
  border-radius: var(--radius-lg);
  margin-bottom: var(--space-6);
  flex-wrap: wrap;
  position: relative;
  overflow: hidden;
}

/* Confetti-dots CSS background on results header */
.results-score-header::after {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    radial-gradient(circle, rgb(255 255 255 / 0.35) 1px, transparent 1px),
    radial-gradient(circle, rgb(255 255 255 / 0.20) 1px, transparent 1px);
  background-size: 20px 20px, 40px 40px;
  background-position: 0 0, 10px 10px;
  pointer-events: none;
}

.results-score-header--great {
  background: linear-gradient(145deg, #ECFDF5 0%, #D1FAE5 100%);
  border: 2px solid #6EE7B7;
}

.results-score-header--ok {
  background: linear-gradient(145deg, #FFFBEB 0%, #FEF3C7 100%);
  border: 2px solid #FCD34D;
}

.results-score-header--poor {
  background: linear-gradient(145deg, var(--color-error-bg) 0%, #FEE2E2 100%);
  border: 2px solid var(--color-error-border);
}

/* Score circle — large, prominent */
.score-circle {
  flex-shrink: 0;
  width: 6rem;
  height: 6rem;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-display);
  font-weight: 900;
  box-shadow: 0 4px 20px rgb(0 0 0 / 0.15);
  animation: popIn 500ms cubic-bezier(0.34, 1.56, 0.64, 1) both;
  position: relative;
  z-index: 1;
}

/* Outer ring decoration */
.score-circle::before {
  content: '';
  position: absolute;
  inset: -5px;
  border-radius: 50%;
  border: 3px dashed rgb(255 255 255 / 0.6);
  animation: spin 12s linear infinite;
}

.score-circle--great {
  background: linear-gradient(135deg, var(--color-leaf) 0%, #0d9488 100%);
  color: #fff;
}

.score-circle--ok {
  background: linear-gradient(135deg, var(--color-sun) 0%, var(--color-sun-dark) 100%);
  color: #fff;
}

.score-circle--poor {
  background: linear-gradient(135deg, var(--color-error) 0%, #C03030 100%);
  color: #fff;
}

.score-pct {
  font-size: 1.4rem;
  font-weight: 900;
  letter-spacing: -0.03em;
  line-height: 1;
}

.score-title {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 800;
  margin-bottom: var(--space-2);
  color: var(--color-ink);
  letter-spacing: -0.02em;
  position: relative;
  z-index: 1;
}

.score-detail {
  font-size: 1rem;
  color: var(--text-muted);
  font-weight: 600;
  position: relative;
  z-index: 1;
}

.score-summary {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  position: relative;
  z-index: 1;
}

/* ---------------------------------------------------------------
   Results — Per-question Breakdown
   --------------------------------------------------------------- */
.results-breakdown {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  margin-bottom: var(--space-6);
}

.result-item {
  border-radius: var(--radius-md);
  padding: var(--space-4) var(--space-5);
  border: 2px solid transparent;
  background: var(--surface-soft);
  transition: transform 100ms ease;
}

.result-item:hover {
  transform: translateX(3px);
}

.result-item--correct {
  border-color: #6EE7B7;
  background: linear-gradient(135deg, #F0FDF4 0%, #ECFDF5 100%);
  border-left: 5px solid var(--color-leaf);
}

.result-item--incorrect {
  border-color: var(--color-error-border);
  background: linear-gradient(135deg, #FFF5F5 0%, var(--color-error-bg) 100%);
  border-left: 5px solid var(--color-error);
}

.result-item-header {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  margin-bottom: var(--space-2);
  flex-wrap: wrap;
}

.result-icon {
  font-size: 1.2rem;
  line-height: 1;
  flex-shrink: 0;
}

.result-qnum {
  font-weight: 700;
  font-size: 0.9375rem;
  color: var(--color-ink);
  flex: 1;
}

.result-points {
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text-muted);
  background: var(--color-cloud);
  border-radius: var(--radius-pill);
  padding: 0.15rem 0.6rem;
  border: 1px solid var(--color-cloud-dark);
}

.result-points--earned {
  color: #065f46;
  background: var(--color-leaf-soft);
  border-color: #6EE7B7;
}

.result-student-answer,
.result-correct-answer {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: var(--space-1);
  display: flex;
  gap: var(--space-2);
  flex-wrap: wrap;
  font-weight: 500;
}

.result-student-label,
.result-correct-label {
  font-weight: 700;
  color: var(--color-ink);
  flex-shrink: 0;
}

.result-correct-value {
  color: var(--color-leaf-dark);
  font-weight: 700;
}

.result-student-value {
  color: var(--color-ink);
  font-weight: 700;
}

.result-explanation {
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-top: var(--space-2);
  font-style: italic;
  line-height: 1.55;
  padding: var(--space-2) var(--space-3);
  background: rgb(59 130 246 / 0.06);
  border-radius: var(--radius-xs);
  border-left: 3px solid var(--color-sky);
}

/* ---------------------------------------------------------------
   Responsive
   --------------------------------------------------------------- */
@media (max-width: 640px) {
  .mode-selection {
    grid-template-columns: 1fr;
  }

  .mode-btn {
    padding: var(--space-6) var(--space-5);
    flex-direction: row;
    text-align: left;
    gap: var(--space-4);
  }

  .mode-btn__icon {
    width: 3rem;
    height: 3rem;
    font-size: 1.75rem;
    flex-shrink: 0;
  }

  .question-text {
    font-size: 1rem;
  }

  .question-input-area {
    padding-left: 0;
    margin-top: var(--space-3);
  }

  .matching-row {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-2);
  }

  .matching-left {
    flex: none;
  }

  .matching-left::after {
    content: ' ↓';
  }

  .results-score-header {
    flex-direction: column;
    align-items: center;
    text-align: center;
    padding: var(--space-6) var(--space-5);
  }

  .score-circle {
    width: 5rem;
    height: 5rem;
  }

  .score-pct {
    font-size: 1.2rem;
  }

  .timer-display {
    font-size: 1.5rem;
  }

  .solve-actions {
    justify-content: stretch;
  }

  .solve-actions .btn {
    width: 100%;
    justify-content: center;
  }

  .result-item {
    padding: var(--space-3) var(--space-4);
  }
}

@media (min-width: 641px) {
  /* Larger question text on bigger screens */
  .question-text {
    font-size: 1.125rem;
  }

  .option-label {
    font-size: 1.0625rem;
  }
}