/* Reusable UI component styles. Depends on tokens.css. */

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: var(--target-min-height);
  padding: var(--space-3) var(--space-6);
  font-family: var(--font-family-base);
  font-size: var(--font-size-lg);
  font-weight: 700;
  color: #fff;
  background: var(--color-primary);
  border: none;
  border-radius: var(--radius-lg);
  cursor: pointer;
  transition: transform 0.08s ease, background 0.15s ease, box-shadow 0.15s ease;
  box-shadow: var(--shadow-card);
}

.btn:hover {
  background: var(--color-primary-dark);
  box-shadow: var(--shadow-card-hover);
}

.btn:active {
  transform: scale(0.97);
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
}

.btn-secondary {
  background: var(--color-surface);
  color: var(--color-primary);
  border: 2px solid var(--color-primary);
}

.btn-secondary:hover {
  background: var(--color-bg);
}

/* Cards */
.card {
  display: block;
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  box-shadow: var(--shadow-card);
  text-decoration: none;
  color: inherit;
  transition: transform 0.1s ease, box-shadow 0.15s ease;
  border: 2px solid transparent;
}

a.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-card-hover);
  border-color: var(--card-accent, var(--color-primary));
}

.card[aria-disabled="true"] {
  opacity: 0.55;
  cursor: not-allowed;
}

.card[aria-disabled="true"]:hover {
  transform: none;
  box-shadow: var(--shadow-card);
  border-color: transparent;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: var(--space-4);
}

/* Hero header (landing page) */
.hero {
  text-align: center;
  padding: clamp(2rem, 4vw, 4rem) clamp(1.5rem, 3vw, 3rem);
  border-radius: var(--radius-lg);
  margin-bottom: clamp(1.5rem, 2vw, 2.5rem);
  background: linear-gradient(
    120deg,
    var(--color-rainbow-blue),
    var(--color-rainbow-teal) 35%,
    var(--color-rainbow-green) 60%,
    var(--color-rainbow-yellow) 80%,
    var(--color-rainbow-orange)
  );
  color: #fff;
}

.hero h1 {
  color: #fff;
  text-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

@media (max-width: 640px) {
  .card-grid {
    grid-template-columns: 1fr;
    gap: 1rem;
  }

  .hero {
    padding: 2rem 1.25rem;
    margin-bottom: 1.5rem;
  }

  .hero h1 {
    font-size: clamp(2.2rem, 10vw, 3rem);
  }
}

.hero p {
  color: #fff;
  opacity: 0.95;
}

/* Subject sections */
.subject-section {
  margin-bottom: var(--space-7);
}

.subject-section + .subject-section {
  border-top: 3px solid var(--color-border);
  padding-top: var(--space-6);
}

.subject-heading {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  color: var(--card-accent, var(--color-text));
}

/* Unit cards: each themed by --card-accent, a rainbow color variable */
.unit-card {
  display: flex;
  flex-direction: column;
  height: 100%;
  border-top: 6px solid var(--card-accent, var(--color-border));
}

.unit-card .progress-badge {
  margin-top: auto;
  align-self: flex-start;
}

.unit-card .unit-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 3rem;
  height: 3rem;
  font-size: var(--font-size-xl);
  border-radius: var(--radius-md);
  background: color-mix(in srgb, var(--card-accent, var(--color-bg)) 18%, white);
  margin-bottom: var(--space-3);
}

.subject-heading .unit-icon {
  background: color-mix(in srgb, var(--card-accent, var(--color-bg)) 22%, white);
  width: 2.5rem;
  height: 2.5rem;
  font-size: var(--font-size-lg);
  margin-bottom: 0;
}

.unit-card.is-locked {
  filter: grayscale(0.55);
  opacity: 0.7;
}

.unit-card.is-locked:hover {
  transform: none;
}

/* Grade cards: large menu on the top-level grade-selector page */
.grade-card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: var(--space-5);
}

.grade-card {
  border-top: 8px solid var(--card-accent, var(--color-border));
  text-align: center;
  padding: var(--space-7) var(--space-5);
}

.grade-card .grade-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 5rem;
  height: 5rem;
  font-size: var(--font-size-2xl);
  border-radius: var(--radius-lg);
  background: color-mix(in srgb, var(--card-accent, var(--color-bg)) 18%, white);
  margin-bottom: var(--space-4);
}

.grade-card h2 {
  font-size: var(--font-size-xl);
  margin-bottom: var(--space-2);
}

@media (max-width: 640px) {
  .grade-card-grid {
    grid-template-columns: 1fr;
  }
}

/* CCSS badge */
.badge {
  display: inline-block;
  font-size: var(--font-size-sm);
  font-weight: 700;
  color: var(--color-primary);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 999px;
  padding: var(--space-1) var(--space-3);
}

/* Callout box — used as a text-feature example in comprehension explainers */
.callout {
  background: var(--color-bg);
  border-left: 4px solid var(--color-primary);
  border-radius: var(--radius-md);
  padding: var(--space-3) var(--space-4);
}

/* Choice tiles (multiple choice component) */
.choice-tile-group {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--space-4);
  margin: var(--space-5) 0;
}

.choice-tile {
  min-height: var(--target-min-height);
  padding: var(--space-4);
  font-family: var(--font-family-base);
  font-size: var(--font-size-lg);
  font-weight: 700;
  color: var(--color-text);
  background: var(--color-surface);
  border: 3px solid var(--color-border);
  border-radius: var(--radius-lg);
  cursor: pointer;
  transition: border-color 0.15s ease, transform 0.08s ease;
}

.choice-tile:hover:not(:disabled) {
  border-color: var(--color-primary);
}

.choice-tile:active:not(:disabled) {
  transform: scale(0.97);
}

.choice-tile:disabled {
  cursor: not-allowed;
}

.choice-tile.is-correct {
  background: var(--color-success-bg);
  border-color: var(--color-success);
  color: var(--color-success);
}

.choice-tile.is-incorrect {
  background: var(--color-error-bg);
  border-color: var(--color-error);
  color: var(--color-error);
}

/* Number line */
.number-line-track {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin: var(--space-5) 0;
  padding: var(--space-4);
  background: var(--color-surface);
  border: 3px solid var(--color-border);
  border-radius: var(--radius-lg);
  font-size: var(--font-size-lg);
  font-weight: 700;
}

.nl-point {
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-md);
  background: var(--color-bg);
}

.nl-point.nl-blank {
  background: var(--color-focus-ring);
}

.nl-arrow {
  color: var(--color-text-muted);
  font-weight: 400;
}

/* Number pad */
.number-pad-display {
  min-height: 3rem;
  font-size: var(--font-size-2xl);
  font-weight: 800;
  text-align: center;
  background: var(--color-surface);
  border: 3px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-3);
  margin: var(--space-4) 0;
}

.number-pad-keys {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-3);
  max-width: 320px;
  margin: 0 auto var(--space-5);
}

.number-pad-key {
  font-size: var(--font-size-xl);
}

.number-pad.is-correct .number-pad-display {
  border-color: var(--color-success);
}

.number-pad.is-incorrect .number-pad-display {
  border-color: var(--color-error);
}

/* Base-ten block builder */
.block-place-group {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: var(--space-4);
  margin: var(--space-5) 0;
}

.block-place {
  background: var(--color-surface);
  border: 3px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
  text-align: center;
}

.block-place-label {
  font-weight: 700;
  color: var(--color-text-muted);
  margin-bottom: var(--space-2);
}

.block-display {
  min-height: 3.5rem;
  font-size: var(--font-size-xl);
  line-height: 1.3;
  word-break: break-all;
  margin-bottom: var(--space-3);
}

.block-controls {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-3);
}

.block-btn {
  min-height: 2.5rem;
  min-width: 2.5rem;
  padding: 0 var(--space-3);
}

.block-count {
  font-size: var(--font-size-lg);
  font-weight: 700;
  min-width: 1.5rem;
}

.base-ten-blocks.is-correct .block-place {
  border-color: var(--color-success);
}

.base-ten-blocks.is-incorrect .block-place {
  border-color: var(--color-error);
}

/* Analog clock */
.clock-face {
  position: relative;
  width: 220px;
  height: 220px;
  margin: var(--space-5) auto;
  background: var(--color-surface);
  border: 4px solid var(--color-border);
  border-radius: 50%;
}

.clock-number {
  position: absolute;
  top: 50%;
  left: 50%;
  font-weight: 700;
  color: var(--color-text);
  transform: rotate(var(--angle)) translate(0, -92px) rotate(calc(-1 * var(--angle)));
  transform-origin: 0 0;
}

.clock-hand {
  position: absolute;
  bottom: 50%;
  left: 50%;
  background: var(--color-text);
  border-radius: 4px;
  transform-origin: bottom center;
}

.clock-hand-hour {
  width: 6px;
  height: 52px;
  margin-left: -3px;
}

.clock-hand-minute {
  width: 4px;
  height: 80px;
  margin-left: -2px;
  background: var(--color-primary);
}

.clock-center {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--color-text);
  transform: translate(-50%, -50%);
}

/* Coin / bill tray */
.coin-tray-items {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-3);
  margin: var(--space-5) 0;
}

.coin-chip {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-2) var(--space-4);
  font-size: var(--font-size-lg);
  font-weight: 700;
  background: var(--color-surface);
  border: 3px solid var(--color-border);
  border-radius: var(--radius-lg);
}

/* Data graphs (line plot / bar graph) */
.line-plot {
  display: flex;
  align-items: flex-end;
  justify-content: center;
  gap: var(--space-5);
  margin: var(--space-5) 0;
  padding: var(--space-4);
  background: var(--color-surface);
  border: 3px solid var(--color-border);
  border-radius: var(--radius-lg);
  border-bottom-width: 4px;
}

.line-plot-col {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.line-plot-marks {
  display: flex;
  flex-direction: column-reverse;
  align-items: center;
  gap: var(--space-1);
  min-height: 2rem;
}

.line-plot-mark {
  color: var(--color-primary);
  font-weight: 800;
}

.line-plot-label {
  margin-top: var(--space-2);
  font-weight: 700;
  color: var(--color-text-muted);
}

.bar-graph {
  display: flex;
  align-items: flex-end;
  justify-content: center;
  gap: var(--space-5);
  margin: var(--space-5) 0;
  padding: var(--space-4);
  background: var(--color-surface);
  border: 3px solid var(--color-border);
  border-radius: var(--radius-lg);
}

.bar-graph-col {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-end;
}

.bar-graph-count {
  font-weight: 700;
  margin-bottom: var(--space-1);
}

.bar-graph-bar {
  width: 48px;
  min-height: 4px;
  background: var(--color-rainbow-blue);
  border-radius: var(--radius-md) var(--radius-md) 0 0;
}

.bar-graph-label {
  margin-top: var(--space-2);
  font-weight: 700;
  color: var(--color-text-muted);
}

/* Array grid */
.array-grid {
  display: grid;
  gap: var(--space-2);
  max-width: 280px;
  margin: var(--space-5) auto;
  padding: var(--space-4);
  background: var(--color-surface);
  border: 3px solid var(--color-border);
  border-radius: var(--radius-lg);
}

.array-grid-cell {
  aspect-ratio: 1;
  background: var(--color-rainbow-blue);
  border-radius: 6px;
}

/* Sentence builder */
.sentence-builder-story {
  min-height: 3rem;
  margin: var(--space-5) 0;
  padding: var(--space-4);
  background: var(--color-surface);
  border: 3px solid var(--color-border);
  border-radius: var(--radius-lg);
}

.sentence-builder-story p {
  margin: 0 0 var(--space-2);
}

.sentence-builder-story p:last-child {
  margin-bottom: 0;
}

.choice-tile.is-picked {
  opacity: 0.4;
}

.sentence-builder.is-correct .sentence-builder-story {
  border-color: var(--color-success);
}

.sentence-builder.is-incorrect .sentence-builder-story {
  border-color: var(--color-error);
}

/* Feedback banner */
.feedback-banner {
  padding: var(--space-4) var(--space-5);
  border-radius: var(--radius-md);
  font-size: var(--font-size-lg);
  font-weight: 700;
  margin: var(--space-4) 0;
}

.feedback-banner.is-correct {
  background: var(--color-success-bg);
  color: var(--color-success);
}

.feedback-banner.is-incorrect {
  background: var(--color-error-bg);
  color: var(--color-error);
}

.feedback-banner .explanation {
  display: block;
  font-weight: 500;
  font-size: var(--font-size-base);
  margin-top: var(--space-2);
  color: var(--color-text);
}

/* Progress badges */
.progress-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  font-size: var(--font-size-sm);
  font-weight: 700;
  border-radius: 999px;
  padding: var(--space-1) var(--space-3);
}

.progress-badge.not-started {
  background: var(--color-bg);
  color: var(--color-text-muted);
  border: 1px solid var(--color-border);
}

/* Home-level cards (subject/unit list, grade picker) get a bigger, vibrant
   "Start" pill in the card's own accent color instead of the muted default —
   locked cards stay muted via the parent's grayscale filter. */
.unit-card .progress-badge.not-started,
.grade-card .progress-badge.not-started {
  background: var(--card-accent, var(--color-primary));
  color: #fff;
  border: none;
  padding: var(--space-2) var(--space-6);
  font-size: var(--font-size-base);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.18);
}

.progress-badge.in-progress {
  background: #fff5e0;
  color: #a26a00;
  border: 1px solid #f2d18a;
}

.progress-badge.mastered {
  background: var(--color-success-bg);
  color: var(--color-success);
  border: 1px solid var(--color-success);
}

/* Exercise session UI */
.session-progress {
  font-size: var(--font-size-base);
  color: var(--color-text-muted);
  font-weight: 700;
  margin-bottom: var(--space-3);
}

.mastery-result {
  text-align: center;
  padding: var(--space-6);
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
}

.mastery-result .stars {
  font-size: var(--font-size-display);
  margin-bottom: var(--space-3);
}

/* Mastery celebration confetti */
.confetti-burst {
  position: relative;
  height: 0;
  overflow: visible;
  pointer-events: none;
}

.confetti-piece {
  position: absolute;
  top: -1rem;
  font-size: 1.5rem;
  animation: confetti-fall 1.6s ease-in forwards;
}

@keyframes confetti-fall {
  0% {
    transform: translateY(0) rotate(0deg);
    opacity: 1;
  }
  100% {
    transform: translateY(120px) rotate(360deg);
    opacity: 0;
  }
}

.celebration-toggle {
  margin-top: var(--space-3);
}

/* Parent dashboard */
.dashboard-stats {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-5);
  margin: var(--space-5) 0;
}

.dashboard-stat {
  flex: 1;
  min-width: 160px;
  text-align: center;
  background: var(--color-surface);
  border: 3px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
}

.dashboard-stat-value {
  font-size: var(--font-size-2xl);
  font-weight: 800;
  color: var(--color-primary);
}

.dashboard-stat-label {
  margin-top: var(--space-1);
  font-weight: 700;
  color: var(--color-text-muted);
}

.dashboard-subject {
  margin: var(--space-6) 0;
}

.dashboard-unit-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.dashboard-unit {
  background: var(--color-surface);
  border: 3px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
}

.dashboard-unit-header {
  display: flex;
  justify-content: space-between;
  font-weight: 700;
  margin-bottom: var(--space-2);
}

.progress-track {
  height: 12px;
  background: var(--color-bg);
  border-radius: 999px;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: var(--color-success);
  border-radius: 999px;
  transition: width 0.3s ease;
}