:root {
  --color-primary: #3454d1;
  --color-primary-container: #e7ecff;
  --color-on-primary-container: #1b2c6b;
  --color-secondary: #b45309;
  --color-secondary-container: #fef3c7;
  --color-on-secondary-container: #78350f;
  --color-surface: #fafaf9;
  --color-surface-container: #f1f1f4;
  --color-surface-container-high: #e7e7ec;
  --color-outline-variant: #dcdce3;
  --color-on-surface: #1c1c22;
  --color-on-surface-variant: #5b5b66;
  --color-success: #15803d;
  --color-success-container: #dcfce7;
  --color-on-success-container: #14532d;
  --color-error: #b3261e;
  --color-error-container: #fce8e6;
  --color-on-error-container: #7a1b15;
  --radius-card: 14px;
  --font-display: "Space Grotesk", sans-serif;
  --font-body: "Inter", sans-serif;
  --font-mono: "JetBrains Mono", monospace;
}
[data-theme="dark"] {
  --color-primary: #8fa6ff;
  --color-primary-container: #26326e;
  --color-on-primary-container: #dde4ff;
  --color-secondary: #f5b84e;
  --color-secondary-container: #4a3410;
  --color-on-secondary-container: #fde9c4;
  --color-surface: #131316;
  --color-surface-container: #1c1c21;
  --color-surface-container-high: #26262d;
  --color-outline-variant: #35353e;
  --color-on-surface: #ededf2;
  --color-on-surface-variant: #a6a6b2;
  --color-success: #4ade80;
  --color-success-container: #123b23;
  --color-on-success-container: #bbf7d0;
  --color-error: #f2867d;
  --color-error-container: #3f1613;
  --color-on-error-container: #fbd5d0;
}
* {
  box-sizing: border-box;
}
html,
body {
  margin: 0;
  padding: 0;
}
body {
  background: var(--color-surface);
  color: var(--color-on-surface);
  font-family: var(--font-body);
  min-height: 100vh;
  transition:
    background 0.25s ease,
    color 0.25s ease;
}
.wrap {
  max-width: 1120px;
  margin: 0 auto;
  padding: 28px 20px 80px;
}
.text-headline-sm {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: -0.01em;
}
.text-body-md {
  font-size: 0.95rem;
  line-height: 1.55;
}
.text-xs {
  font-size: 0.72rem;
}
.font-bold {
  font-weight: 700;
}
.font-medium {
  font-weight: 500;
}
.mono {
  font-family: var(--font-mono);
}
.muted {
  color: var(--color-on-surface-variant);
}

.topbar {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 22px;
  flex-wrap: wrap;
}
.brand-eyebrow {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-primary);
  font-weight: 700;
  margin-bottom: 4px;
}
.brand-sub {
  margin-top: 4px;
  max-width: 46ch;
}
.stat-cluster {
  display: flex;
  gap: 10px;
  align-items: center;
  flex-wrap: wrap;
}
.stat-chip {
  background: var(--color-surface-container);
  border: 1px solid var(--color-outline-variant);
  border-radius: 10px;
  padding: 8px 14px;
  text-align: center;
  min-width: 76px;
}
.stat-chip .num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 1.05rem;
  display: block;
}
.stat-chip .lbl {
  font-size: 0.62rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-on-surface-variant);
}
.icon-btn {
  border: 1px solid var(--color-outline-variant);
  background: var(--color-surface-container);
  color: var(--color-on-surface);
  border-radius: 10px;
  width: 38px;
  height: 38px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 1rem;
}
.icon-btn:hover {
  background: var(--color-surface-container-high);
}

.filter-bar {
  background: var(--color-surface-container);
  border: 1px solid var(--color-outline-variant);
  border-radius: 12px;
  padding: 14px 16px;
  margin-bottom: 20px;
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  align-items: flex-end;
}
.filter-group label {
  display: block;
  margin-bottom: 5px;
  color: var(--color-on-surface-variant);
}
.filter-group select {
  background: var(--color-surface);
  border: 1px solid var(--color-outline-variant);
  border-radius: 8px;
  padding: 8px 10px;
  font-size: 0.85rem;
  color: var(--color-on-surface);
  min-width: 140px;
  font-family: var(--font-body);
}
.segmented {
  display: flex;
  border: 1px solid var(--color-outline-variant);
  border-radius: 8px;
  overflow: hidden;
}
.segmented button {
  border: none;
  background: var(--color-surface);
  color: var(--color-on-surface);
  padding: 8px 14px;
  font-size: 0.82rem;
  cursor: pointer;
  font-family: var(--font-body);
  font-weight: 500;
  border-right: 1px solid var(--color-outline-variant);
}
.segmented button:last-child {
  border-right: none;
}
.segmented button.active {
  background: var(--color-primary-container);
  color: var(--color-on-primary-container);
}
.filter-count {
  margin-left: auto;
  font-size: 0.8rem;
  color: var(--color-on-surface-variant);
  white-space: nowrap;
  align-self: center;
}
.reset-btn {
  border: 1px solid var(--color-outline-variant);
  background: transparent;
  color: var(--color-on-surface-variant);
  border-radius: 8px;
  padding: 8px 12px;
  font-size: 0.8rem;
  cursor: pointer;
  font-family: var(--font-body);
}
.reset-btn:hover {
  background: var(--color-surface-container-high);
  color: var(--color-on-surface);
}
.topic-multiselect {
  position: relative;
}
.topic-dd-btn {
  background: var(--color-surface);
  border: 1px solid var(--color-outline-variant);
  border-radius: 8px;
  padding: 8px 10px;
  font-size: 0.85rem;
  cursor: pointer;
  min-width: 150px;
  text-align: left;
  color: var(--color-on-surface);
  font-family: var(--font-body);
}
.topic-dd-panel {
  position: absolute;
  top: calc(100% + 6px);
  left: 0;
  background: var(--color-surface);
  border: 1px solid var(--color-outline-variant);
  border-radius: 10px;
  padding: 8px;
  z-index: 20;
  min-width: 220px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
  max-height: 260px;
  overflow-y: auto;
}
.topic-dd-panel label {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 6px;
  border-radius: 6px;
  font-size: 0.83rem;
  cursor: pointer;
  color: var(--color-on-surface);
}
.topic-dd-panel label:hover {
  background: var(--color-surface-container);
}

.main-grid {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 22px;
  align-items: start;
}
@media (max-width: 860px) {
  .main-grid {
    grid-template-columns: 1fr;
  }
}

.palette-card {
  background: var(--color-surface-container);
  border: 1px solid var(--color-outline-variant);
  border-radius: var(--radius-card);
  padding: 14px;
  position: sticky;
  top: 16px;
}
.palette-title {
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-on-surface-variant);
  margin-bottom: 10px;
  font-weight: 700;
}
.palette-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 6px;
}
.pal-btn {
  aspect-ratio: 1;
  border-radius: 7px;
  border: 1px solid var(--color-outline-variant);
  background: var(--color-surface);
  color: var(--color-on-surface-variant);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
}
.pal-btn.current {
  outline: 2px solid var(--color-primary);
  outline-offset: 1px;
}
.pal-btn.answered-correct {
  background: var(--color-success-container);
  color: var(--color-on-success-container);
  border-color: transparent;
}
.pal-btn.answered-incorrect {
  background: var(--color-error-container);
  color: var(--color-on-error-container);
  border-color: transparent;
}
.pal-btn.flagged::after {
  content: "●";
  color: var(--color-secondary);
  font-size: 0.5rem;
  position: relative;
  top: -8px;
  left: 8px;
}
.palette-legend {
  margin-top: 12px;
  display: flex;
  flex-direction: column;
  gap: 5px;
  font-size: 0.68rem;
  color: var(--color-on-surface-variant);
}
.legend-dot {
  display: inline-block;
  width: 9px;
  height: 9px;
  border-radius: 3px;
  margin-right: 6px;
  vertical-align: middle;
}

.progress-track {
  height: 6px;
  background: var(--color-surface-container-high);
  border-radius: 4px;
  overflow: hidden;
  margin: 16px 0 0;
}
.progress-fill {
  height: 100%;
  background: var(--color-primary);
  border-radius: 4px;
  transition: width 0.3s ease;
}

.card {
  background: var(--color-surface);
  border: 1px solid var(--color-outline-variant);
  border-radius: var(--radius-card);
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.04);
}
.card-level-1 {
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
}
.p-6 {
  padding: 26px;
}
.space-y-6 > * + * {
  margin-top: 22px;
}

.q-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 12px;
  flex-wrap: wrap;
}
.q-number {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 0.78rem;
  color: var(--color-primary);
  letter-spacing: 0.04em;
}
.q-meta-row {
  display: flex;
  gap: 8px;
  align-items: center;
  flex-wrap: wrap;
  margin-top: 6px;
}
.badge {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 4px 10px;
  border-radius: 999px;
  font-size: 0.68rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  background: var(--color-secondary-container);
  color: var(--color-on-secondary-container);
}
.badge-diff-Easy {
  background: var(--color-success-container);
  color: var(--color-on-success-container);
}
.badge-diff-Medium {
  background: var(--color-secondary-container);
  color: var(--color-on-secondary-container);
}
.badge-diff-Hard {
  background: var(--color-error-container);
  color: var(--color-on-error-container);
}
.badge-outline {
  background: transparent;
  border: 1px solid var(--color-outline-variant);
  color: var(--color-on-surface-variant);
}
.flag-btn {
  border: 1px solid var(--color-outline-variant);
  background: transparent;
  border-radius: 8px;
  padding: 6px 10px;
  font-size: 0.75rem;
  cursor: pointer;
  color: var(--color-on-surface-variant);
  display: flex;
  gap: 6px;
  align-items: center;
}
.flag-btn.active {
  background: var(--color-secondary-container);
  color: var(--color-on-secondary-container);
  border-color: transparent;
}

.question-text {
  font-size: 1.05rem;
  line-height: 1.65;
  font-weight: 500;
}

.options {
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.option-row {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 13px 15px;
  border-radius: 10px;
  border: 1.5px solid var(--color-outline-variant);
  cursor: pointer;
  background: var(--color-surface);
  transition:
    border-color 0.15s ease,
    background 0.15s ease;
}
.option-row:hover {
  background: var(--color-surface-container);
}
.option-row.selected {
  border-color: var(--color-primary);
  background: var(--color-primary-container);
}
.option-row.correct {
  border-color: var(--color-success);
  background: var(--color-success-container);
}
.option-row.incorrect {
  border-color: var(--color-error);
  background: var(--color-error-container);
}
.option-row.disabled {
  cursor: default;
}
.radio-circle {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  border: 2px solid var(--color-outline-variant);
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
}
.option-row.selected .radio-circle {
  border-color: var(--color-primary);
}
.option-row.selected .radio-circle::after {
  content: "";
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--color-primary);
}
.option-row.correct .radio-circle {
  border-color: var(--color-success);
}
.option-row.correct .radio-circle::after {
  content: "✓";
  color: var(--color-success);
  font-size: 13px;
  font-weight: 700;
}
.option-row.incorrect .radio-circle {
  border-color: var(--color-error);
}
.option-row.incorrect .radio-circle::after {
  content: "✕";
  color: var(--color-error);
  font-size: 12px;
  font-weight: 700;
}
.option-letter {
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--color-on-surface-variant);
  width: 16px;
}
.option-label {
  font-size: 0.94rem;
  line-height: 1.45;
}

.action-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}
.btn {
  border: none;
  border-radius: 10px;
  padding: 11px 20px;
  font-size: 0.88rem;
  font-weight: 600;
  cursor: pointer;
  font-family: var(--font-body);
}
.btn-primary {
  background: var(--color-primary);
  color: #fff;
}
.btn-primary:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}
.btn-ghost {
  background: transparent;
  border: 1px solid var(--color-outline-variant);
  color: var(--color-on-surface);
}
.nav-btns {
  display: flex;
  gap: 8px;
}

.feedback-banner {
  border-radius: 10px;
  padding: 12px 16px;
  font-weight: 600;
  font-size: 0.9rem;
  display: flex;
  align-items: center;
  gap: 8px;
}
.feedback-banner.correct {
  background: var(--color-success-container);
  color: var(--color-on-success-container);
}
.feedback-banner.incorrect {
  background: var(--color-error-container);
  color: var(--color-on-error-container);
}

.explain {
  border-top: 1px dashed var(--color-outline-variant);
  padding-top: 16px;
}
.explain-title {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-primary);
  font-weight: 700;
  margin-bottom: 8px;
}

.empty-state {
  text-align: center;
  padding: 60px 20px;
  color: var(--color-on-surface-variant);
}
.empty-state .glyph {
  font-family: var(--font-mono);
  font-size: 2rem;
  margin-bottom: 10px;
  color: var(--color-outline-variant);
}

.skeleton {
  background: linear-gradient(
    90deg,
    var(--color-surface-container) 25%,
    var(--color-surface-container-high) 37%,
    var(--color-surface-container) 63%
  );
  background-size: 400% 100%;
  animation: skeleton-loading 1.4s ease infinite;
  border-radius: 8px;
}
@keyframes skeleton-loading {
  0% {
    background-position: 100% 50%;
  }
  100% {
    background-position: 0 50%;
  }
}
.skeleton-line {
  height: 14px;
  margin-bottom: 10px;
}
.skeleton-block {
  height: 180px;
}

@media (max-width: 520px) {
  .p-6 {
    padding: 18px;
  }
  .filter-bar {
    flex-direction: column;
    align-items: stretch;
  }
  .filter-count {
    margin-left: 0;
  }
}
/* ===== POWERED BY MINIMAL ===== */
.powered-by-minimal {
  font-family: var(--font-body);
  font-size: 11px;
  font-weight: 500;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 6px;
  margin-bottom: 12px;
}

/* The glowing green dot */
.status-dot {
  width: 6px;
  height: 6px;
  background-color: var(--color-secondary); /* Action Green */
  border-radius: 50%;
  box-shadow: 0 0 8px var(--color-secondary);
  animation: pulseOpacity 2s infinite; /* Reuses your existing animation! */
}

.powered-by-minimal a {
  color: var(--text);
  text-decoration: none;
  font-weight: 700;
  border-bottom: 1px dashed var(--color-outline-variant);
  transition: all 0.2s ease;
}

.powered-by-minimal a:hover {
  color: var(--color-primary);
  border-bottom-color: var(--color-primary);
}
/* =========================================
   MOBILE RESPONSIVENESS FIXES
   ========================================= */

/* 1. Fix the Main Grid & Sticky Palette on Mobile */
@media (max-width: 860px) {
  .main-grid {
    grid-template-columns: 1fr;
  }

  /* Move the question area ABOVE the palette on mobile */
  #questionArea {
    order: -1;
  }

  /* Disable sticky positioning so the palette doesn't block the screen */
  .palette-card {
    position: static;
    margin-top: 24px;
  }
}

/* 2. Stack the Filter Bar cleanly on small screens */
@media (max-width: 640px) {
  .filter-bar {
    flex-direction: column;
    align-items: stretch;
    gap: 12px;
  }

  .filter-group {
    width: 100%;
  }

  /* Make inputs and buttons take full width */
  .filter-group select,
  .topic-dd-btn,
  .reset-btn {
    width: 100%;
    min-width: 0;
    text-align: left;
  }

  .reset-btn {
    text-align: center;
  }

  /* Make the segmented control stretch evenly */
  .segmented {
    width: 100%;
  }
  .segmented button {
    flex: 1;
    text-align: center;
  }

  /* Center the filter count at the bottom */
  .filter-count {
    margin-left: 0;
    width: 100%;
    text-align: center;
    padding-top: 12px;
    border-top: 1px solid var(--color-outline-variant);
  }
}

/* 3. Fix Multi-line Option Alignment */
.option-row {
  align-items: flex-start; /* Aligns radio button to the top line of text */
}

.radio-circle {
  margin-top: 2px; /* Fine-tune alignment with the first line of text */
}

/* 4. Prevent Topic Dropdown from Overflowing the Screen */
.topic-dd-panel {
  max-width: calc(100vw - 40px); /* Prevents horizontal scrolling */
  left: auto;
  right: 0; /* Anchors to the right side of the button */
}