/* ===========================
   StudyEngine Design System
   "Analog Precision"
   Loads AFTER Pico.css
   =========================== */

/* --- Design Tokens --- */
:root {
  /* Spacing scale (4px base) */
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 20px;
  --space-6: 24px;
  --space-8: 32px;
  --space-10: 40px;
  --space-12: 48px;
  --space-16: 64px;

  /* Radii */
  --radius-none: 0px;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --radius-full: 999px;

  /* Shadows — cool-tinted */
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.04), 0 1px 4px rgba(0,0,0,0.03);
  --shadow-md: 0 2px 8px rgba(0,0,0,0.06), 0 1px 3px rgba(0,0,0,0.04);
  --shadow-lg: 0 4px 16px rgba(0,0,0,0.08), 0 2px 6px rgba(0,0,0,0.04);

  /* Typography */
  --font-display: 'Instrument Serif', Georgia, serif;
  --font-body: 'Manrope', system-ui, sans-serif;

  /* Buttons */
  --btn-bg: #1A1A1A;
  --btn-color: #FAFAF8;
  --btn-radius: var(--radius-sm);

  /* Mastery tiers — accent for fills/icons, text for use on light backgrounds */
  --mastered: #2BA876;
  --mastered-bg: #E4F5ED;
  --mastered-text: #0D5A3A;

  --solid: #D4952A;
  --solid-bg: #FBF0DC;
  --solid-text: #6B4408;

  --shaky: #E07347;
  --shaky-bg: #FDECE5;
  --shaky-text: #7A2E14;

  --weak: #DC4F4F;
  --weak-bg: #FCE9E9;
  --weak-text: #7C1D1D;

  --unproven: #7B8DC0;
  --unproven-bg: #EBEEF6;
  --unproven-text: #303D66;

  /* Mastery tiers — accessible text colors for use on --bg-primary (4.5:1+) */
  --mastered-on-bg: #1E8A62;
  --solid-on-bg: #A07A1A;
  --shaky-on-bg: #BA5530;
  --weak-on-bg: #C03E3E;
  --unproven-on-bg: #5A6FA0;

  /* Primary accent — copper/terracotta */
  --primary: #B86E3A;
  --primary-bg: #FDF4EC;
  --primary-text: #7A4520;
  --primary-hover: #A05E2E;
  --primary-solid: #B86E3A;
  --primary-solid-hover: #A05E2E;

  /* Info */
  --info: #4A8FCC;
  --info-bg: #EAF2FA;
  --info-text: #1A4A78;

  /* Neutrals */
  --text-primary: #1A1A1A;
  --text-secondary: #6B6B6B;
  --text-tertiary: #6E6E6C;
  --bg-primary: #FAFAF8;
  --bg-secondary: #F2F2EE;
  --bg-tertiary: #E8E8E4;
  --border-light: rgba(0, 0, 0, 0.07);
  --border-medium: rgba(0, 0, 0, 0.14);

  /* Grain overlay */
  --grain: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.03'/%3E%3C/svg%3E");
}

/* Light mode Pico overrides */
:root,
[data-theme="light"] {
  --pico-background-color: var(--bg-primary);
  --pico-color: var(--text-primary);
  --pico-card-background-color: var(--bg-secondary);
  --pico-muted-color: var(--text-tertiary);
  --pico-primary: var(--primary);
  --pico-primary-hover: var(--primary-hover);
  --pico-border-color: var(--border-light);
  --pico-form-element-border-color: var(--border-medium);
  --pico-border-radius: var(--radius-sm);
}

/* --- Dark Mode (single source of truth — applied via data-theme attribute) --- */
[data-theme="dark"] {
  --mastered: #5DCAA5;
  --mastered-bg: #0A2E22;
  --mastered-text: #9FE1CB;
  --solid: #EFA83A;
  --solid-bg: #2E1E06;
  --solid-text: #FAC775;
  --shaky: #F0997B;
  --shaky-bg: #3A1A0C;
  --shaky-text: #F5C4B3;
  --weak: #F09595;
  --weak-bg: #3A1212;
  --weak-text: #F7C1C1;
  --unproven: #9AADE0;
  --unproven-bg: #1A2240;
  --unproven-text: #C4D1F0;
  --primary: #D4955E;
  --primary-bg: #2A1C0E;
  --primary-text: #E8C09A;
  --primary-hover: #E0A572;
  --primary-solid: #C4824A;
  --primary-solid-hover: #D4955E;
  --btn-bg: #D4955E;
  --btn-color: #111113;
  --info: #7CB5E4;
  --info-bg: #0A2240;
  --info-text: #B5D4F4;
  --text-primary: #E6E6E2;
  --text-secondary: #9A9A94;
  --text-tertiary: #8E8E8A;
  --bg-primary: #111113;
  --bg-secondary: #1A1A1D;
  --bg-tertiary: #242428;
  --border-light: rgba(255, 255, 255, 0.08);
  --border-medium: rgba(255, 255, 255, 0.14);
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.2), 0 1px 4px rgba(0,0,0,0.15);
  --shadow-md: 0 2px 8px rgba(0,0,0,0.3), 0 1px 3px rgba(0,0,0,0.2);
  --shadow-lg: 0 4px 16px rgba(0,0,0,0.4), 0 2px 6px rgba(0,0,0,0.25);
  --pico-background-color: var(--bg-primary);
  --pico-color: var(--text-primary);
  --pico-card-background-color: var(--bg-secondary);
  --pico-card-sectioning-background-color: var(--bg-secondary);
  --pico-muted-color: var(--text-tertiary);
  --pico-muted-border-color: var(--border-light);
  --pico-primary: var(--primary);
  --pico-primary-hover: var(--primary-hover);
  --pico-secondary: var(--text-secondary);
  --pico-border-color: var(--border-light);
  --pico-form-element-background-color: var(--bg-secondary);
  --pico-form-element-border-color: var(--border-medium);
  --pico-form-element-color: var(--text-primary);
  --mastered-on-bg: #3DD99A;
  --solid-on-bg: #E8B04E;
  --shaky-on-bg: #F09060;
  --weak-on-bg: #F06060;
  --unproven-on-bg: #96AAD4;
}

/* --- Animations --- */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}
@keyframes scaleIn {
  from { opacity: 0; transform: scale(0.9); }
  to { opacity: 1; transform: scale(1); }
}
@keyframes shimmer {
  0% { background-position: -200% 0; }
  100% { background-position: 200% 0; }
}

/* --- Global Overrides --- */
body {
  background: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 15px;
  font-weight: 420;
  line-height: 1.55;
  min-height: 100vh;
  min-height: 100dvh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Subtle grain texture */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  background-image: var(--grain);
  background-repeat: repeat;
  background-size: 256px;
  pointer-events: none;
  z-index: 9999;
  opacity: 1;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 400;
  letter-spacing: -0.01em;
}
h1 { font-size: 28px; }
h2 { font-size: 22px; }
h3 { font-size: 18px; }
h4 { font-size: 16px; }

/* --- Pico Form/Button Overrides --- */
input:not([type="checkbox"]):not([type="radio"]),
select,
textarea {
  padding: var(--space-2) var(--space-3);
  font-size: 14px;
  border-radius: var(--radius-sm);
  margin-bottom: var(--space-3);
}
select {
  background-size: 12px;
}
label {
  font-size: 13px;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: var(--space-1);
  letter-spacing: 0.01em;
}

/* All buttons */
button,
[role="button"],
input[type="submit"],
input[type="button"] {
  font-family: var(--font-body);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.02em;
  border-radius: var(--btn-radius);
  padding: var(--space-2) var(--space-4);
  transition: all 0.2s ease;
}

main.container {
  max-width: 720px;
  margin-left: auto;
  margin-right: auto;
  animation: fadeInUp 0.35s ease-out;
}

/* --- Tier Utility Classes --- */
.tier-unproven .topic-score { color: var(--unproven); }
.tier-weak .topic-score { color: var(--weak); }
.tier-shaky .topic-score { color: var(--shaky); }
.tier-solid .topic-score { color: var(--solid); }
.tier-mastered .topic-score { color: var(--mastered); }

.tier-unproven .mastery-bar-fill { background: var(--unproven); }
.tier-weak .mastery-bar-fill { background: var(--weak); }
.tier-shaky .mastery-bar-fill { background: var(--shaky); }
.tier-solid .mastery-bar-fill { background: var(--solid); }
.tier-mastered .mastery-bar-fill { background: var(--mastered); }

/* --- Scorecard Header --- */
.scorecard-header {
  display: flex;
  gap: var(--space-6);
  align-items: flex-end;
  margin-bottom: var(--space-6);
}
.hero-stat {
  flex-shrink: 0;
}
.hero-number {
  font-family: var(--font-display);
  font-size: 56px;
  font-weight: 400;
  line-height: 1;
  letter-spacing: -0.02em;
}
.hero-pct {
  font-size: 22px;
  color: var(--text-tertiary);
  font-weight: 400;
}
.hero-label {
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-tertiary);
  margin-top: var(--space-1);
}

/* --- Mastery Tooltip --- */
.mastery-tooltip {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
}
.mastery-tooltip-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 14px;
  height: 14px;
  border-radius: var(--radius-full);
  border: 1px solid var(--text-tertiary);
  font-size: 9px;
  font-weight: 700;
  font-style: normal;
  color: var(--text-tertiary);
  cursor: help;
  line-height: 1;
  flex-shrink: 0;
  outline: none;
  /* Reset Pico [role="button"] overrides */
  background: none;
  padding: 0;
  box-shadow: none;
  --pico-background-color: transparent;
}
.mastery-tooltip-icon:focus,
.mastery-tooltip-icon:focus-visible {
  border-color: var(--text-primary);
  color: var(--text-primary);
  box-shadow: none;
}
.mastery-tooltip-text {
  visibility: hidden;
  opacity: 0;
  position: absolute;
  bottom: calc(100% + 8px);
  left: 50%;
  transform: translateX(-50%);
  width: 260px;
  padding: var(--space-3);
  background: var(--bg-primary);
  border: 1px solid var(--border-medium);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  font-size: 12px;
  line-height: 1.55;
  color: var(--text-secondary);
  z-index: 10;
  transition: opacity 0.15s, visibility 0.15s;
  pointer-events: none;
}
.mastery-tooltip-icon:hover + .mastery-tooltip-text,
.mastery-tooltip-icon:focus + .mastery-tooltip-text {
  visibility: visible;
  opacity: 1;
}
@media (max-width: 600px) {
  .mastery-tooltip-text {
    bottom: auto;
    top: calc(100% + 8px);
    left: 0;
    transform: none;
    width: 240px;
  }
}

@media (max-width: 600px) {
  .scorecard-header { flex-direction: column; gap: var(--space-3); align-items: stretch; }
}

/* --- Metric Cards (scorecard summary) --- */
.metric-cards {
  display: flex;
  gap: 1px;
  margin-bottom: var(--space-6);
  flex: 1;
  border-radius: var(--radius-md);
  overflow: hidden;
}
.scorecard-header .metric-cards {
  margin-bottom: 0;
}
.metric-card {
  flex: 1;
  background: var(--bg-secondary);
  padding: var(--space-3);
}
.metric-card .label {
  font-size: 9px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-tertiary);
  margin-bottom: 2px;
}
.metric-card .value {
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 400;
  margin: 0;
}

@media (max-width: 600px) {
  .metric-cards { flex-wrap: wrap; }
  .metric-card { flex: 1 1 30%; }
}

/* --- Mastery Bars --- */
.mastery-bar {
  width: 80px;
  height: 3px;
  background: var(--border-light);
  border-radius: var(--radius-full);
  overflow: hidden;
}
.mastery-bar-fill {
  height: 100%;
  border-radius: var(--radius-full);
  transition: width 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

/* --- Topic Rows (scorecard) --- */
.topic-row {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-2) 0;
  border-bottom: 1px solid var(--border-light);
  cursor: pointer;
  transition: background 0.15s;
  border-radius: var(--radius-sm);
  margin: 0 calc(-1 * var(--space-2));
  padding-left: var(--space-2);
  padding-right: var(--space-2);
  /* Reset Pico [role="button"] overrides */
  background: none;
  color: inherit;
  border-top: none;
  border-left: none;
  border-right: none;
  font-weight: inherit;
  text-align: left;
  line-height: inherit;
  box-shadow: none;
  --pico-background-color: transparent;
}
.topic-row:hover {
  background: var(--bg-secondary);
  --pico-background-color: var(--bg-secondary);
}
.topic-name {
  flex: 1;
  font-size: 14px;
  font-weight: 520;
}
.topic-units {
  font-size: 12px;
  color: var(--text-secondary);
  min-width: 70px;
}
.topic-score {
  font-size: 14px;
  font-weight: 600;
  min-width: 44px;
  text-align: right;
  font-variant-numeric: tabular-nums;
}
.subtopic-count {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-tertiary);
  color: var(--text-tertiary);
  font-size: 10px;
  font-weight: 600;
  width: 18px;
  height: 18px;
  border-radius: var(--radius-full);
  margin-left: var(--space-1);
  vertical-align: middle;
}
.recognition-recall-gap {
  font-size: 10px;
  font-weight: 600;
  color: var(--shaky-on-bg);
  border: 1px solid var(--shaky);
  border-radius: var(--radius-sm);
  padding: 0 4px;
  cursor: help;
}

.topic-trend {
  font-size: 12px;
  min-width: 20px;
  text-align: center;
}

@media (max-width: 600px) {
  .topic-row { gap: var(--space-2); }
  .topic-name {
    min-width: 0;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }
  .topic-units { display: none; }
}

/* --- Trend Arrows --- */
.trend-up { color: var(--mastered); }
.trend-down { color: var(--weak); }
.trend-flat { color: var(--text-tertiary); }

/* --- Tier Sections (scorecard groupings) --- */
.tier-section { margin-bottom: var(--space-6); }
.tier-header {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin-bottom: var(--space-2);
}
.tier-dot {
  width: 8px;
  height: 8px;
  border-radius: var(--radius-full);
  flex-shrink: 0;
}
.tier-name {
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 400;
  font-style: italic;
}
.tier-count {
  font-size: 12px;
  color: var(--text-tertiary);
  font-weight: 500;
}

/* --- Suggestion Card --- */
.suggestion-card {
  padding: var(--space-4);
  border-left: 3px solid var(--primary);
  margin-bottom: var(--space-6);
  background: var(--primary-bg);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}
.suggestion-card .suggestion-label {
  font-size: 10px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--primary);
  margin-bottom: var(--space-1);
}
.suggestion-card .suggestion-text {
  font-size: 14px;
  color: var(--primary-text);
  line-height: 1.6;
}
.suggestion-card .suggestion-text a {
  color: var(--primary);
  font-weight: 600;
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 2px;
}

/* --- Secondary Suggestions --- */
.secondary-row {
  display: flex;
  gap: var(--space-2);
  margin-bottom: var(--space-6);
}
.secondary-item {
  flex: 1;
  padding: var(--space-3);
  border-left: 2px solid var(--border-medium);
  font-size: 13px;
  position: relative;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  background: var(--bg-secondary);
  transition: background 0.15s;
}
.secondary-item:hover {
  background: var(--bg-tertiary);
}
.secondary-item .sec-text {
  display: block;
  color: var(--text-secondary);
  line-height: 1.4;
}
.secondary-item a {
  font-size: 12px;
  color: var(--primary);
  font-weight: 600;
  text-decoration: none;
  transition: color 0.15s ease;
}
.secondary-item a:hover {
  color: var(--primary-hover);
}
.secondary-item a::after {
  content: '';
  position: absolute;
  inset: 0;
}
@media (max-width: 600px) {
  .secondary-row {
    flex-direction: column;
    gap: var(--space-2);
  }
}

/* --- Session Tier Picker --- */
.tier-picker { display: flex; flex-direction: column; gap: var(--space-2); }
.tier-option {
  background: var(--bg-primary);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  padding: var(--space-4) var(--space-5);
  cursor: pointer;
  transition: border-color 0.15s, background 0.15s, box-shadow 0.15s;
}
.tier-option:hover {
  border-color: var(--border-medium);
  background: var(--bg-secondary);
}
.tier-option.selected {
  border-left: 3px solid var(--primary);
  background: var(--primary-bg);
  box-shadow: var(--shadow-sm);
}
.tier-option-top {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: var(--space-1);
}
.tier-option-name {
  font-size: 15px;
  font-weight: 600;
}
.tier-option-time {
  font-size: 13px;
  color: var(--text-secondary);
}
.tier-option-desc {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* --- Quiz-Taking UI --- */
.quiz-container {
  max-width: 640px;
  margin: 0 auto;
}
.quiz-progress {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin-bottom: var(--space-8);
  font-size: 13px;
  color: var(--text-secondary);
  font-weight: 500;
  font-variant-numeric: tabular-nums;
}
.quiz-progress-bar {
  flex: 1;
  height: 3px;
  background: var(--border-light);
  border-radius: var(--radius-full);
  overflow: hidden;
}
.quiz-progress-fill {
  height: 100%;
  background: var(--primary);
  border-radius: var(--radius-full);
  transition: width 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}
.quiz-question-text {
  font-size: 16px;
  line-height: 1.7;
  margin-bottom: var(--space-6);
}

.quiz-options { display: flex; flex-direction: column; gap: var(--space-2); }
.quiz-option {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-4);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: border-color 0.15s, background 0.15s, box-shadow 0.15s;
  font-size: 14px;
  min-height: 48px;
}
.quiz-option:hover {
  background: var(--bg-secondary);
  border-color: var(--border-medium);
}
.quiz-option.selected,
.htmx-request .quiz-option {
  border-left: 3px solid var(--primary);
  background: var(--primary-bg);
  box-shadow: var(--shadow-sm);
}
.quiz-option.correct {
  border-color: var(--mastered);
  background: var(--mastered-bg);
}
.quiz-option.wrong {
  border-color: var(--weak);
  background: var(--weak-bg);
}
.quiz-option-letter {
  width: 26px;
  height: 26px;
  border-radius: var(--radius-full);
  border: 1.5px solid var(--border-medium);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  font-weight: 600;
  flex-shrink: 0;
  color: var(--text-secondary);
  transition: all 0.15s;
}
.quiz-option.selected .quiz-option-letter { background: var(--primary-solid); color: white; border-color: var(--primary-solid); }
.quiz-option.correct .quiz-option-letter { background: var(--mastered); color: white; border-color: var(--mastered); }
.quiz-option.wrong .quiz-option-letter { background: var(--weak); color: white; border-color: var(--weak); }

.quiz-textarea {
  width: 100%;
  min-height: 100px;
  padding: var(--space-3);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  font-size: 14px;
  line-height: 1.6;
  resize: vertical;
  transition: border-color 0.15s;
}
.quiz-textarea:focus {
  border-color: var(--primary);
  outline: none;
  box-shadow: 0 0 0 3px rgba(184, 110, 58, 0.1);
}

.quiz-skip {
  font-size: 13px;
  color: var(--text-tertiary);
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-2) 0;
  margin-top: var(--space-2);
}
.quiz-skip:hover { color: var(--text-secondary); }

.quiz-nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: var(--space-8);
  padding-top: var(--space-4);
  border-top: 1px solid var(--border-light);
}

/* --- Results Page --- */
.results-score {
  text-align: center;
  margin-bottom: var(--space-8);
}
.results-score .score-number {
  font-family: var(--font-display);
  font-size: 52px;
  font-weight: 400;
  letter-spacing: -0.02em;
  animation: scaleIn 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}
.results-score .score-label {
  font-size: 14px;
  color: var(--text-secondary);
  margin-top: var(--space-1);
}

.result-topic {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-2) 0;
  border-bottom: 1px solid var(--border-light);
  font-size: 13px;
}
.result-topic:last-child { border-bottom: none; }
.result-topic-name { flex: 1; }
.result-topic-score { font-weight: 600; min-width: 50px; text-align: right; font-variant-numeric: tabular-nums; }

/* --- Review Cards --- */
.review-card {
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-light);
  padding: var(--space-4) var(--space-5);
  margin-bottom: var(--space-4);
  border-left: 3px solid var(--weak);
}
.review-card.tier-shaky { border-left-color: var(--shaky); }
.review-card.tier-solid { border-left-color: var(--solid); }
.review-card-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: var(--space-3);
}
.review-card-topic {
  font-size: 15px;
  font-weight: 600;
}
.review-card-mastery {
  font-size: 13px;
  color: var(--text-secondary);
}

.review-explanation {
  font-size: 14px;
  line-height: 1.7;
  margin-bottom: var(--space-4);
}

/* --- Pills / Tags --- */
.pill {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: 3px var(--space-3);
  border-radius: var(--radius-full);
  font-size: 12px;
  font-weight: 600;
  background: var(--primary-bg);
  color: var(--primary-text);
  letter-spacing: 0.01em;
}
.pill-sm {
  font-size: 11px;
  padding: 2px var(--space-2);
}
.pill-remove {
  cursor: pointer;
  opacity: 0.6;
  font-size: 12px;
  background: none;
  border: none;
  color: inherit;
  min-height: auto;
  padding: 0;
}
.pill-remove:hover { opacity: 1; }
.pills { display: flex; flex-wrap: wrap; gap: var(--space-1); }

/* --- Loading States --- */
.loading-dots::after {
  content: '';
  animation: dots 1.5s steps(4, end) infinite;
}
@keyframes dots {
  0% { content: ''; }
  25% { content: '.'; }
  50% { content: '..'; }
  75% { content: '...'; }
}
.loading-pulse {
  animation: pulse 1.5s ease-in-out infinite;
}
@keyframes pulse {
  0%, 100% { opacity: 0.4; }
  50% { opacity: 1; }
}

.streaming-placeholder {
  height: 1em;
  width: 60%;
  background: linear-gradient(90deg, var(--bg-secondary) 25%, var(--bg-tertiary) 50%, var(--bg-secondary) 75%);
  background-size: 200% 100%;
  border-radius: var(--radius-sm);
  animation: shimmer 1.5s ease-in-out infinite;
}

/* --- Expandable Detail (scorecard drill-down) --- */
.expandable-detail {
  background: var(--bg-secondary);
  border-radius: var(--radius-sm);
  font-size: 13px;
  line-height: 1.6;
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  padding: 0 var(--space-3);
  margin-top: 0;
  transition: max-height 0.3s ease, opacity 0.2s ease, padding 0.3s ease, margin-top 0.3s ease;
}
.expandable-detail.open {
  max-height: 1200px;
  opacity: 1;
  padding: var(--space-3);
  margin-top: var(--space-1);
}
.attempt-row {
  display: flex;
  justify-content: space-between;
  padding: var(--space-1) 0;
  border-bottom: 1px solid var(--border-light);
}
.attempt-row:last-child { border-bottom: none; }
.attempt-date { color: var(--text-secondary); }
.attempt-source { color: var(--text-secondary); font-size: 12px; }
.attempt-score { font-weight: 600; }

/* --- Buttons --- */
button[type="submit"],
input[type="submit"] {
  --pico-primary: var(--btn-bg);
  --pico-primary-hover: var(--btn-bg);
}

.btn-primary {
  background: var(--btn-bg);
  color: var(--btn-color);
  border: none;
  padding: var(--space-2) var(--space-5);
  cursor: pointer;
  border-radius: var(--btn-radius);
  transition: transform 0.15s, opacity 0.15s;
}
.btn-primary:hover {
  opacity: 0.88;
  transform: translateY(-1px);
}
.btn-primary:active {
  transform: translateY(0);
}
.btn-disabled { pointer-events: none; opacity: 0.4; }
.verification-widget:has(.htmx-request) .quiz-option { pointer-events: none; opacity: 0.6; }
.verification-widget:has(.htmx-request) .htmx-request .quiz-option { opacity: 1; }

.btn-outline {
  background: transparent;
  border: 1px solid var(--border-medium);
  padding: var(--space-2) var(--space-5);
  cursor: pointer;
  color: var(--text-primary);
  border-radius: var(--btn-radius);
  transition: all 0.15s;
}
.btn-outline:hover {
  background: var(--bg-secondary);
  color: var(--text-primary);
  border-color: var(--text-tertiary);
}

.btn-small {
  padding: var(--space-1) var(--space-3);
  font-size: 12px;
}

.btn-danger {
  color: var(--weak);
  border-color: var(--weak);
}

a.btn-primary,
a.btn-outline {
  text-decoration: none;
  display: inline-block;
}

/* --- Upload Zone --- */
.upload-zone {
  border: 2px dashed var(--border-medium);
  border-radius: var(--radius-md);
  padding: var(--space-8);
  text-align: center;
  color: var(--text-secondary);
  transition: border-color 0.2s, background 0.2s;
}
.upload-zone:hover,
.upload-zone.dragover {
  border-color: var(--primary);
  background: var(--primary-bg);
}

/* --- Generic Card --- */
.card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  padding: var(--space-4) var(--space-5);
  transition: background 0.15s;
}
.card-link:hover .card {
  background: var(--bg-tertiary);
}

/* --- Tier Option Stats --- */
.tier-option-stats {
  display: flex;
  gap: var(--space-4);
  margin-top: var(--space-2);
  font-size: 12px;
  color: var(--text-tertiary);
}
.tier-option-stats span {
  font-weight: 600;
  color: var(--text-secondary);
}

/* --- Section Label --- */
.section-label {
  font-family: var(--font-body);
  font-size: 10px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-tertiary);
  margin: var(--space-10) 0 var(--space-4);
  padding-bottom: var(--space-2);
  border-bottom: 1px solid var(--border-light);
}

/* --- Layout Utilities --- */
.page-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--space-6);
}
.page-header h2 { margin: 0; }

.back-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  font-size: 13px;
  font-weight: 500;
  color: var(--text-tertiary);
  text-decoration: none;
  margin-bottom: var(--space-3);
  transition: color 0.15s;
}
.back-link:hover { color: var(--text-primary); }

.card-link {
  text-decoration: none;
  color: inherit;
  display: block;
}

.card-title-row {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: var(--space-2);
}

.card-title {
  font-size: 16px;
  font-weight: 600;
}

.card-description {
  font-size: 13px;
  color: var(--text-secondary);
  margin-bottom: var(--space-2);
}

.card-stats {
  font-size: 12px;
  color: var(--text-tertiary);
}

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

.breadcrumb {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-3) var(--space-4);
  font-size: 13px;
  font-weight: 500;
  color: var(--text-secondary);
  border-bottom: 1px solid var(--border-light);
}
.breadcrumb a {
  color: var(--text-tertiary);
  text-decoration: none;
  transition: color 0.15s;
}
.breadcrumb a:hover { color: var(--text-primary); }
.breadcrumb-utils {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}
.breadcrumb-utils .theme-toggle {
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-1);
  color: var(--text-tertiary);
  display: flex;
  align-items: center;
  min-height: auto;
  border-radius: var(--radius-sm);
  transition: color 0.15s, background 0.15s;
}
.breadcrumb-utils .theme-toggle:hover {
  color: var(--text-primary);
  background: var(--bg-secondary);
}
.breadcrumb-signout {
  color: var(--text-tertiary);
  padding: var(--space-1);
  display: flex;
  align-items: center;
  border-radius: var(--radius-sm);
  transition: color 0.15s, background 0.15s;
}
.breadcrumb-signout:hover {
  color: var(--text-primary);
  background: var(--bg-secondary);
}

/* --- Feedback / Answer Display --- */
.feedback-box {
  padding: var(--space-3);
  border-radius: var(--radius-sm);
  background: var(--bg-secondary);
  margin-bottom: var(--space-6);
  font-size: 14px;
  line-height: 1.65;
}

.answer-label {
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-secondary);
  margin-bottom: var(--space-1);
}

.answer-display {
  padding: var(--space-3);
  border-radius: var(--radius-sm);
  font-size: 14px;
}
.answer-display.correct {
  background: var(--mastered-bg);
  border: 1px solid var(--mastered);
}
.answer-display.incorrect {
  background: var(--weak-bg);
  border: 1px solid var(--weak);
}

.result-actions {
  display: flex;
  gap: var(--space-2);
  flex-wrap: wrap;
}

/* --- Detail Panel --- */
.detail-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--space-2);
}
.detail-header span { font-weight: 600; }

.subtopic-label {
  font-weight: 600;
  margin-bottom: var(--space-1);
  font-size: 12px;
  color: var(--text-secondary);
}

.low-confidence-note {
  font-size: 12px;
  color: var(--text-tertiary);
  font-style: italic;
}

.recent-attempts-label {
  font-weight: 600;
  margin-bottom: var(--space-1);
  font-size: 12px;
  color: var(--text-secondary);
}

/* --- Login --- */
.login-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 80vh;
  min-height: 80dvh;
}

.login-google-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-3);
  width: 100%;
  padding: var(--space-3) var(--space-5);
  border-radius: var(--btn-radius);
  border: 1px solid var(--border-medium);
  background: var(--bg-primary);
  color: var(--text-primary);
  font-size: 14px;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: all 0.15s;
}
.login-google-btn:hover {
  background: var(--bg-secondary);
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}

.login-magic-btn {
  width: 100%;
  padding: var(--space-3) var(--space-5);
  border-radius: var(--btn-radius);
  border: 1px solid var(--border-light);
  background: transparent;
  color: var(--text-secondary);
  font-size: 13px;
  cursor: pointer;
  transition: all 0.15s;
}
.login-magic-btn:hover {
  background: var(--bg-secondary);
  color: var(--text-primary);
}

/* --- Study Actions --- */
.study-actions {
  display: flex;
  gap: var(--space-2);
  margin-bottom: var(--space-6);
}
.study-action {
  flex: 1;
  margin: 0;
  min-width: 0;
}
@media (max-width: 600px) {
  .study-actions { flex-direction: column; }
}

.study-btn {
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  padding: var(--space-3) var(--space-4);
  border-radius: var(--btn-radius);
  background: var(--bg-secondary);
  color: var(--text-primary);
  border: 1px solid var(--primary);
  cursor: pointer;
  text-align: left;
  transition: all 0.15s;
  min-height: auto;
}
.study-btn:hover {
  background: var(--bg-tertiary);
  transform: translateY(-1px);
}
.study-btn:disabled {
  opacity: 0.6;
  transform: none;
  cursor: wait;
}


.study-btn-title {
  font-size: 15px;
  font-weight: 600;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 100%;
}
.study-btn-detail {
  font-size: 12px;
  color: var(--text-secondary);
  margin-top: 2px;
}

/* --- Empty States --- */
.empty-state {
  text-align: center;
  padding: var(--space-16) var(--space-4);
}
.empty-state-icon {
  color: var(--text-tertiary);
  opacity: 0.2;
  margin-bottom: var(--space-4);
}
.empty-state-icon svg {
  width: 48px;
  height: 48px;
}
.empty-state p {
  color: var(--text-secondary);
  font-size: 15px;
  line-height: 1.6;
  margin-bottom: var(--space-4);
}

/* --- Error Page --- */
.error-page {
  text-align: center;
  padding: var(--space-16) var(--space-4);
}
.error-code {
  font-family: var(--font-display);
  font-size: 72px;
  font-weight: 400;
  color: var(--text-tertiary);
  margin-bottom: var(--space-1);
  opacity: 0.3;
  letter-spacing: -0.02em;
}
.error-page h2 { margin-bottom: var(--space-2); }
.error-page p {
  color: var(--text-secondary);
  margin-bottom: var(--space-6);
}

/* --- Exam Prep Unit Selector --- */
.exam-unit-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  margin-bottom: var(--space-4);
}
.exam-unit-option {
  display: block;
  cursor: pointer;
}
.exam-unit-option input { display: none; }
.exam-unit-card {
  padding: var(--space-4) var(--space-5);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  transition: all 0.15s;
}
.exam-unit-card:hover {
  border-color: var(--border-medium);
}
.exam-unit-option input:checked + .exam-unit-card {
  border: 2px solid var(--primary);
  background: var(--primary-bg);
  box-shadow: var(--shadow-sm);
}

/* --- Upload Zone Icon --- */
.upload-zone-icon {
  color: var(--text-tertiary);
  opacity: 0.3;
  margin-bottom: var(--space-3);
  transition: all 0.2s;
}
.upload-zone-icon svg {
  width: 32px;
  height: 32px;
}
.upload-zone:hover .upload-zone-icon,
.upload-zone.dragover .upload-zone-icon {
  opacity: 0.7;
  transform: translateY(-2px);
  color: var(--primary);
}

/* --- Focus Styles --- */
.tab:focus-visible,
.btn-primary:focus-visible,
.btn-outline:focus-visible,
.tier-option:focus-visible,
.topic-row:focus-visible,
button.breadcrumb-signout:focus-visible,
.theme-toggle:focus-visible,
.study-btn:focus-visible,
.quiz-skip:focus-visible,
.rating-btn:focus-visible,
.card-link:focus-visible,
.unit-mastery-row:focus-visible,
.back-link:focus-visible,
.login-google-btn:focus-visible,
.login-magic-btn:focus-visible,
.mastery-toggle-btn:focus-visible,
.secondary-item a:focus-visible,
details summary:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}
.quiz-option:focus-within {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

/* --- Quiz Feedback Accents --- */
.quiz-feedback-correct .feedback-box {
  border-left: 3px solid var(--mastered);
}
.quiz-feedback-incorrect .feedback-box {
  border-left: 3px solid var(--weak);
}

/* --- Loading Steps (quiz generation) --- */
.loading-steps {
  max-width: 320px;
  margin: 0 auto;
}
.loading-step {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-2) 0;
  color: var(--text-tertiary);
  font-size: 14px;
  transition: color 0.3s;
}
.loading-step.active {
  color: var(--text-primary);
}
.loading-step.done {
  color: var(--mastered);
}
.step-dot {
  width: 8px;
  height: 8px;
  border-radius: var(--radius-full);
  background: var(--border-medium);
  flex-shrink: 0;
  transition: background 0.3s;
}
.loading-step.active .step-dot {
  background: var(--primary);
  animation: pulse 1.5s ease-in-out infinite;
}
.loading-step.done .step-dot {
  background: var(--mastered);
}

/* --- Wrong Answer Review (results page) --- */
.wrong-answer-item {
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  margin-bottom: var(--space-2);
  overflow: hidden;
}
.wrong-answer-summary {
  padding: var(--space-3);
  cursor: pointer;
  display: flex;
  flex-direction: column;
  gap: 2px;
  font-size: 14px;
  list-style: none;
}
.wrong-answer-summary::-webkit-details-marker { display: none; }
.wrong-answer-summary::marker { display: none; }
.wrong-answer-topic {
  font-size: 11px;
  font-weight: 600;
  color: var(--text-tertiary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.wrong-answer-prompt { font-weight: 600; }
.wrong-answer-detail {
  padding: 0 var(--space-3) var(--space-3);
  font-size: 14px;
  line-height: 1.6;
}
.wrong-answer-choices {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  margin-bottom: var(--space-2);
}
.wrong-answer-choice {
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-sm);
  font-size: 13px;
}
.wrong-answer-choice.correct { background: var(--mastered-bg); color: var(--mastered-text); }
.wrong-answer-choice.wrong { background: var(--weak-bg); color: var(--weak-text); }
.wrong-answer-pair {
  font-size: 13px;
  margin-bottom: var(--space-2);
  line-height: 1.8;
}
.wrong-answer-feedback {
  margin-top: var(--space-2);
  font-size: 13px;
  color: var(--text-secondary);
  font-style: italic;
}

/* --- Flashcard Drill --- */
.flashcard {
  background: var(--bg-secondary);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: var(--space-8) var(--space-6);
  cursor: pointer;
  min-height: 200px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s;
  margin-bottom: var(--space-6);
  outline: none;
  box-shadow: var(--shadow-sm);
}
.flashcard:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}
.flashcard:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}
.flashcard-front,
.flashcard-back {
  text-align: center;
  width: 100%;
}
.flashcard-back {
  display: none;
}
.flashcard.flipped .flashcard-front {
  display: none;
}
.flashcard.flipped .flashcard-back {
  display: block;
}
.flashcard.flipped {
  cursor: default;
}
.flashcard.flipped:hover {
  transform: none;
}
.flashcard-label {
  font-size: 10px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-tertiary);
  margin-bottom: var(--space-3);
}
.flashcard-text {
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 400;
  line-height: 1.45;
  color: var(--text-primary);
}
.flashcard-hint {
  font-size: 12px;
  color: var(--text-tertiary);
  margin-top: var(--space-6);
}

.flashcard-ratings {
  display: flex;
  gap: var(--space-2);
  justify-content: center;
}
.rating-btn {
  flex: 1;
  max-width: 120px;
  padding: var(--space-2) var(--space-3);
  border-radius: var(--btn-radius);
  border: 1px solid var(--border-light);
  background: var(--bg-secondary);
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s;
}
.rating-btn:hover {
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}
.rating-key {
  display: inline-block;
  font-size: 10px;
  font-weight: 700;
  background: var(--bg-tertiary);
  border-radius: 3px;
  padding: 1px 5px;
  margin-right: var(--space-1);
  vertical-align: middle;
}
.rating-again { border-color: var(--weak); color: var(--weak-text); }
.rating-again:hover { background: var(--weak-bg); }
.rating-hard { border-color: var(--shaky); color: var(--shaky-text); }
.rating-hard:hover { background: var(--shaky-bg); }
.rating-good { border-color: var(--mastered); color: var(--mastered-text); }
.rating-good:hover { background: var(--mastered-bg); }
.rating-easy { border-color: var(--primary); color: var(--primary-text); }
.rating-easy:hover { background: var(--primary-bg); }

@media (max-width: 600px) {
  .flashcard-ratings { flex-wrap: wrap; }
  .rating-btn { max-width: none; flex: 1 1 40%; }
}

/* --- Mastery View Toggle --- */
.mastery-toggle {
  display: inline-flex;
  gap: 1px;
  margin-bottom: var(--space-6);
  background: var(--border-light);
  border-radius: var(--radius-sm);
  overflow: hidden;
}
.mastery-toggle-btn {
  padding: var(--space-2) var(--space-4);
  font-size: 13px;
  font-weight: 600;
  background: var(--bg-secondary);
  color: var(--text-tertiary);
  border: none;
  cursor: pointer;
  transition: all 0.15s;
  min-height: 36px;
}
@media (hover: none) {
  .mastery-toggle-btn {
    min-height: 44px;
  }
}
.mastery-toggle-btn.active {
  background: var(--bg-primary);
  color: var(--text-primary);
}
.mastery-toggle-btn:hover:not(.active) {
  color: var(--text-secondary);
}

/* --- Unit Mastery Row --- */
.unit-mastery-row {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-2);
  border-bottom: 1px solid var(--border-light);
  text-decoration: none;
  color: inherit;
  transition: background 0.15s;
  border-radius: var(--radius-sm);
  margin: 0 calc(-1 * var(--space-2));
}
.unit-mastery-row:hover {
  background: var(--bg-secondary);
}
.unit-mastery-name {
  flex: 1;
  font-size: 14px;
  font-weight: 520;
}
.unit-mastery-topics {
  font-size: 12px;
  color: var(--text-tertiary);
  white-space: nowrap;
}

/* --- Mastery Ring --- */
.mastery-ring {
  position: relative;
  width: 48px;
  height: 48px;
  flex-shrink: 0;
}
.mastery-ring svg {
  transform: rotate(-90deg);
  width: 48px;
  height: 48px;
}
.mastery-ring-label {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

/* --- Materials Footnote --- */
.materials-footnote {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-1);
  font-size: 12px;
  color: var(--text-tertiary);
  margin-top: var(--space-8);
  padding-top: var(--space-4);
  border-top: 1px solid var(--border-light);
}
.materials-label {
  font-weight: 600;
  color: var(--text-secondary);
}
.material-pill {
  display: inline-flex;
  align-items: center;
  gap: 3px;
  padding: 1px var(--space-2);
  background: var(--bg-secondary);
  border-radius: var(--radius-full);
  font-size: 12px;
  white-space: nowrap;
}
.material-pill-x {
  background: none;
  border: none;
  color: var(--text-tertiary);
  cursor: pointer;
  padding: 0 2px;
  font-size: 14px;
  line-height: 1;
  min-height: auto;
  transition: color 0.15s;
}
.material-pill-x:hover {
  color: var(--weak);
}
.materials-add {
  display: inline-flex;
  align-items: center;
  color: var(--text-tertiary);
  transition: color 0.15s;
}
.materials-add:hover {
  color: var(--text-primary);
}

/* --- Drag Handle --- */
.drag-handle {
  cursor: grab;
  color: var(--text-tertiary);
  font-size: 18px;
  line-height: 1;
  padding: var(--space-1) 2px;
  user-select: none;
  touch-action: none;
  flex-shrink: 0;
  transition: color 0.15s;
}
.drag-handle:hover {
  color: var(--text-secondary);
}
.drag-handle:active {
  cursor: grabbing;
}

/* --- Unit Card --- */
.unit-card {
  display: block;
  text-decoration: none;
  color: inherit;
  margin-bottom: var(--space-3);
}
.unit-card .card-title-row {
  align-items: center;
}

/* --- Drag-and-Drop States --- */
.unit-card.dragging {
  opacity: 0.4;
}
.unit-card.drag-over {
  border-top: 2px solid var(--primary);
}
.drag-ghost {
  position: fixed;
  pointer-events: none;
  z-index: 1000;
  opacity: 0.85;
  transform: rotate(1.5deg);
  box-shadow: var(--shadow-lg);
  max-width: calc(100vw - 2rem);
}
.drag-ghost .card {
  margin: 0;
}

/* --- Conversation messages --- */
.review-message {
  padding: var(--space-3);
  border-radius: var(--radius-md);
  margin-bottom: var(--space-2);
  font-size: 14px;
  line-height: 1.6;
}
.review-message-student {
  background: var(--primary-bg);
  margin-left: var(--space-8);
}
.review-message-tutor {
  background: var(--bg-secondary);
  margin-right: var(--space-8);
}

/* --- Question Bank --- */
.question-card {
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  margin-bottom: var(--space-2);
  overflow: hidden;
}
.question-card[open] {
  border-color: var(--border-medium);
  box-shadow: var(--shadow-sm);
}
.question-summary {
  padding: var(--space-3);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-2);
  font-size: 14px;
  list-style: none;
}
.question-summary::-webkit-details-marker { display: none; }
.question-summary::marker { content: ""; }
.question-summary::after {
  content: "\25B8";
  color: var(--text-tertiary);
  font-size: 12px;
  flex-shrink: 0;
  transition: transform 0.15s ease;
}
.question-card[open] .question-summary::after {
  transform: rotate(90deg);
}
.question-summary:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}
.question-prompt {
  flex: 1;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.question-edit-form {
  padding: 0 var(--space-3) var(--space-3);
}
.question-edit-form textarea,
.question-edit-form input[type="text"] {
  font-size: 14px;
  margin-bottom: var(--space-2);
}
.question-choice-row {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  margin-bottom: var(--space-1);
  cursor: pointer;
  min-height: 44px;
  transition: background 0.15s;
}
.question-choice-row:hover,
.question-choice-row:focus-within {
  background: var(--bg-secondary);
}
.question-choice-row input[type="radio"] {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
}
.question-choice-correct {
  border-left: 3px solid var(--mastered);
}
@media (max-width: 600px) {
  .question-filters {
    flex-direction: column;
  }
  .question-filters select {
    width: 100%;
  }
  .question-summary {
    flex-direction: column;
    align-items: flex-start;
  }
  .question-prompt {
    white-space: normal;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
  }
}

/* --- Confidence slider --- */
input[type="range"].unset {
  opacity: 0.4;
}
input[type="range"].unset::-webkit-slider-thumb {
  opacity: 1;
}
input[type="range"].unset::-moz-range-thumb {
  opacity: 1;
}

/* --- Skip link (accessibility) --- */
.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  z-index: 200;
  padding: var(--space-2) var(--space-4);
  background: var(--btn-bg);
  color: var(--btn-color);
  font-size: 14px;
  text-decoration: none;
  border-radius: 0 0 var(--radius-sm) 0;
}
.skip-link:focus {
  left: 0;
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

/* --- Sign-out button --- */
button.breadcrumb-signout {
  background: none;
  border: none;
  padding: 0;
  cursor: pointer;
  color: inherit;
  display: flex;
  align-items: center;
  line-height: 1;
}
button.breadcrumb-signout:hover {
  opacity: 0.7;
}

/* --- Visually Hidden (accessible hiding for form inputs) --- */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* --- Priority Stack Action Cards --- */
.action-card {
  display: block;
  padding: var(--space-4);
  margin-bottom: var(--space-2);
  background: var(--bg-secondary);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  text-decoration: none;
  color: var(--text-primary);
  transition: background 0.15s, transform 0.15s;
  cursor: pointer;
}
.action-card:hover {
  background: var(--bg-tertiary);
  transform: translateY(-1px);
}
.action-card-hero {
  background: var(--bg-secondary);
  border-left: 3px solid var(--primary);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  padding: var(--space-5) var(--space-4);
  margin-bottom: var(--space-4);
}
.action-card-hero:hover {
  background: var(--bg-tertiary);
}
.action-time {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-tertiary);
  display: block;
  margin-bottom: var(--space-1);
}
.action-card-hero .action-time {
  color: var(--primary-text);
}
.action-text {
  font-size: 14px;
  line-height: 1.5;
}
.action-card-hero .action-text {
  font-size: 15px;
  font-weight: 500;
  color: var(--text-primary);
}
.action-arrow {
  float: right;
  color: var(--text-tertiary);
  font-size: 14px;
}
.mastery-summary {
  font-size: 13px;
  color: var(--text-tertiary);
  margin-top: var(--space-4);
  text-align: center;
}
.mastery-summary a {
  color: var(--text-secondary);
  text-decoration: none;
}
.mastery-summary a:hover {
  color: var(--primary);
}

/* --- Collapsible Scorecard on Units --- */
.scorecard-collapse {
  margin-bottom: var(--space-6);
  border-bottom: 1px solid var(--border-light);
  padding-bottom: var(--space-4);
}
.scorecard-collapse-summary {
  display: flex;
  align-items: baseline;
  cursor: pointer;
  list-style: none;
  padding: var(--space-2) 0;
}
.scorecard-collapse-summary::-webkit-details-marker {
  display: none;
}
.scorecard-collapse-summary::marker {
  content: "";
}
.scorecard-collapse-summary::after {
  content: '';
  border: none;
  border-right: 2px solid var(--text-tertiary);
  border-bottom: 2px solid var(--text-tertiary);
  display: inline-block;
  padding: 3px;
  transform: rotate(45deg);
  transition: transform 0.15s;
  margin-left: auto;
}
.scorecard-collapse[open] .scorecard-collapse-summary::after {
  transform: rotate(-135deg);
}
.scorecard-collapse-body {
  padding-top: var(--space-2);
}

/* --- Landing page --- */
*, *::before, *::after { box-sizing: border-box; }

.landing-nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px 24px;
  max-width: 720px;
  margin: 0 auto;
}
.landing-logo {
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 700;
  color: var(--text-primary);
  text-decoration: none;
}
.landing-signin {
  font-size: 13px;
  font-weight: 600;
  padding: 8px 18px;
  border-radius: var(--radius-sm);
  background: var(--btn-bg);
  color: var(--btn-color);
  text-decoration: none;
  transition: opacity 0.15s;
}
.landing-signin:hover { opacity: 0.85; }

.landing-hero {
  text-align: center;
  padding: 56px 24px 40px;
  max-width: 600px;
  margin: 0 auto;
}
.landing-eyebrow {
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--primary);
  font-weight: 600;
  margin-bottom: 12px;
}
.landing-headline {
  font-family: var(--font-display);
  font-size: 36px;
  line-height: 1.15;
  color: var(--text-primary);
  margin-bottom: 16px;
}
.landing-subtext {
  font-size: 16px;
  line-height: 1.6;
  color: var(--text-secondary);
  max-width: 480px;
  margin: 0 auto;
}

.landing-contrast {
  padding: 32px 24px;
  background: var(--bg-secondary);
}
.landing-contrast-grid {
  display: flex;
  gap: 20px;
  max-width: 600px;
  margin: 0 auto;
}
.landing-card {
  flex: 1;
  padding: 20px;
  background: var(--bg-primary);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
}
.landing-card-label {
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 8px;
}
.landing-card-label--problem { color: var(--weak); }
.landing-card-label--fix { color: var(--mastered); }
.landing-card p {
  font-size: 14px;
  line-height: 1.6;
  color: var(--text-secondary);
}

.landing-steps {
  padding: 48px 24px;
  max-width: 520px;
  margin: 0 auto;
}
.landing-steps h2 {
  font-family: var(--font-display);
  font-size: 22px;
  text-align: center;
  margin-bottom: 28px;
  color: var(--text-primary);
}
.landing-step {
  display: flex;
  gap: 14px;
  align-items: flex-start;
  margin-bottom: 22px;
}
.landing-step-num {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
  background: var(--primary-bg);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 14px;
  flex-shrink: 0;
}
.landing-step strong {
  display: block;
  font-size: 15px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 2px;
}
.landing-step span {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.5;
}

.landing-science {
  padding: 32px 24px;
  background: var(--bg-secondary);
  text-align: center;
}
.landing-science h3 {
  font-family: var(--font-display);
  font-size: 18px;
  color: var(--text-primary);
  margin-bottom: 8px;
}
.landing-science p {
  font-size: 13px;
  color: var(--text-secondary);
  max-width: 440px;
  margin: 0 auto;
  line-height: 1.6;
}

.landing-cta {
  padding: 48px 24px;
  text-align: center;
}
.landing-cta h2 {
  font-family: var(--font-display);
  font-size: 22px;
  color: var(--text-primary);
  margin-bottom: 8px;
}
.landing-cta p {
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: 24px;
}
.landing-form {
  display: flex;
  gap: 8px;
  max-width: 380px;
  margin: 0 auto;
}
.landing-form input[type="email"] {
  flex: 1;
  padding: 10px 14px;
  border: 1px solid var(--border-medium);
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-family: var(--font-body);
  background: var(--bg-primary);
  color: var(--text-primary);
}
.landing-form input[type="email"]::placeholder {
  color: var(--text-tertiary);
}
.landing-form button {
  padding: 10px 20px;
  background: var(--primary-solid);
  color: #fff;
  border: none;
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-weight: 600;
  font-family: var(--font-body);
  cursor: pointer;
  white-space: nowrap;
  transition: background 0.15s;
}
.landing-form button:hover {
  background: var(--primary-solid-hover);
}

@media (max-width: 540px) {
  .landing-headline { font-size: 28px; }
  .landing-contrast-grid { flex-direction: column; }
  .landing-form { flex-direction: column; }
  .landing-form button { width: 100%; }
}

/* --- Utility classes --- */
.hint-text {
  font-size: 13px;
  color: var(--text-secondary);
}
.info-box {
  padding: var(--space-3) var(--space-4);
  background: var(--bg-secondary);
  border-radius: var(--radius-sm);
}
.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;
}
.score-historical {
  text-decoration: line-through;
  opacity: 0.5;
  font-size: 12px;
}

/* --- Shared scorecard layout --- */
.shared-scorecard {
  max-width: 720px;
  padding-top: var(--space-8);
}
.shared-scorecard-subtitle {
  font-size: 13px;
  color: var(--text-tertiary);
}
.shared-scorecard-metrics {
  margin-bottom: var(--space-6);
}
.shared-scorecard-empty {
  color: var(--text-secondary);
}
.shared-scorecard-footer {
  margin-top: var(--space-12);
  padding-top: var(--space-4);
  border-top: 1px solid var(--border-light);
  font-size: 12px;
  color: var(--text-tertiary);
  text-align: center;
}

/* --- Reduced motion --- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* --- Quiz gate (weak-topic interstitial) --- */
.gate-topic-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  margin-bottom: var(--space-6);
}
.gate-topic-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-3) var(--space-4);
  background: var(--bg-secondary);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
}
.gate-topic-info {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  min-width: 0;
}
.gate-topic-name {
  font-size: 14px;
  font-weight: 520;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.gate-topic-score {
  font-size: 13px;
  font-weight: 600;
  font-variant-numeric: tabular-nums;
  flex-shrink: 0;
}
.gate-actions {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  margin-top: var(--space-6);
  padding-top: var(--space-5);
  border-top: 1px solid var(--border-light);
}
.gate-override-btn {
  color: var(--text-tertiary);
  border-color: var(--border-light);
  font-size: 13px;
}

/* --- Calibration badge --- */
.calibration-badge {
  font-size: 11px;
  font-weight: 600;
  padding: 0 4px;
  border-radius: var(--radius-full);
  cursor: help;
}
.calibration-badge.overconfident {
  background: var(--shaky-bg);
  color: var(--shaky-on-bg);
}
.calibration-badge.underconfident {
  background: var(--mastered-bg);
  color: var(--mastered-on-bg);
}

/* --- Analytics Page --- */
.analytics-page-title {
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 400;
  margin-bottom: var(--space-1);
}
.analytics-page-subtitle {
  font-size: 13px;
  color: var(--text-secondary);
  margin-bottom: var(--space-6);
}
.analytics-section {
  margin-bottom: var(--space-8);
}
.analytics-section-title {
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 400;
  margin-bottom: var(--space-3);
  color: var(--text-primary);
}
.analytics-bar-chart,
.analytics-tier-bars,
.analytics-accuracy-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}
.analytics-bar-row,
.analytics-accuracy-row {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}
.analytics-bar-label {
  font-size: 12px;
  color: var(--text-secondary);
  min-width: 72px;
  display: flex;
  align-items: center;
  gap: var(--space-2);
}
.analytics-bar-value-group {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  flex: 1;
}
.analytics-bar-track {
  flex: 1;
  height: 6px;
  background: var(--border-light);
  border-radius: var(--radius-full);
  overflow: hidden;
}
.analytics-bar-fill {
  height: 100%;
  background: var(--primary);
  transition: width 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  min-width: 2px;
}
.analytics-bar-value {
  font-size: 12px;
  font-weight: 600;
  min-width: 32px;
  text-align: right;
  font-variant-numeric: tabular-nums;
}
.analytics-accuracy-date {
  font-size: 11px;
  color: var(--text-secondary);
  min-width: 48px;
}
.analytics-untested {
  margin-top: var(--space-3);
}
.analytics-untested-label {
  font-size: 12px;
  color: var(--text-secondary);
  margin-bottom: var(--space-2);
}
.analytics-untested-pills {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}
.metric-unit {
  font-size: 13px;
  font-family: var(--font-body);
}
.pill--unproven {
  background: var(--unproven-bg);
  color: var(--unproven-text);
}
.card-stats-warning {
  color: var(--weak-text);
}