:root {
  color-scheme: light;
  --bg: #eef6f7;
  --surface: #ffffff;
  --surface-alt: #f4fbfb;
  --text: #14323d;
  --navy: #14323d;
  --muted: #5f737b;
  --line: rgba(20, 50, 61, 0.1);
  --shadow: 0 18px 50px rgba(20, 50, 61, 0.1), 0 0 0 1px rgba(20, 50, 61, 0.08);
  --radius: 26px;
  --radius-sm: 16px;
  --teal: #19a9a1;
  --teal-dark: #0e7975;
  --teal-soft: #e2f7f5;
  --yellow: #ffc857;
  --success: #1f7a41;
  --success-soft: #e8f5eb;
  --danger: #9b1c1c;
  --danger-soft: #fdecec;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

body {
  min-height: 100vh;
  font-size: 16.5px;
  line-height: 1.5;
  background:
    radial-gradient(circle at 16% 8%, rgba(25, 169, 161, 0.17), transparent 28rem),
    linear-gradient(180deg, #eef6f7 0%, #f8fbfb 55%, #eef6f7 100%);
}

button,
select,
a {
  font: inherit;
}

button {
  border: 0;
  cursor: pointer;
}

select {
  appearance: none;
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 0.85rem 1rem;
  background: var(--surface);
  color: var(--text);
}

select:disabled,
button:disabled {
  opacity: 0.55;
  cursor: not-allowed;
}

main {
  display: grid;
  gap: 1rem;
}

h1,
h2,
h3,
p {
  margin: 0;
}

ul {
  margin: 0;
  padding-left: 1.2rem;
}

.app-shell {
  width: min(1120px, calc(100vw - 1.25rem));
  margin: 0 auto;
  padding: max(0.75rem, env(safe-area-inset-top)) 0 max(1.5rem, env(safe-area-inset-bottom));
}

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 0.9rem;
  padding: 0.8rem 0.95rem;
}

.brand-lockup {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--navy);
  text-decoration: none;
}

.brand-lockup strong,
.brand-lockup small {
  display: block;
  line-height: 1.1;
}

.brand-lockup strong {
  font-size: 1rem;
  font-weight: 900;
}

.brand-lockup small {
  color: var(--muted);
  font-size: 0.78rem;
  margin-top: 0.12rem;
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border-radius: 16px;
  color: #fff;
  background: var(--teal);
  border: 3px solid #fff;
  box-shadow: 0 8px 20px rgba(25, 169, 161, 0.28);
  font-weight: 900;
  letter-spacing: -0.06em;
}

.menu-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border-radius: 16px;
  background: var(--surface-alt);
  color: var(--navy);
  border: 1px solid var(--line);
  font-weight: 900;
}

.card,
.topic-card,
.subcard,
.metric-card,
.flashcard,
.quiz-question-card,
.results-panel,
.review-card,
.coach-readiness-card,
.coach-action-card {
  background: var(--surface);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.card,
.section-card {
  padding: 1.1rem;
}

.hero {
  display: grid;
  gap: 1rem;
  overflow: hidden;
  background: linear-gradient(135deg, #ffffff 0%, #ffffff 48%, #e8f8f6 100%);
  border: 1px solid rgba(20, 50, 61, 0.08);
}

.hero-illustration {
  display: grid;
  place-items: center;
  min-height: 220px;
  border-radius: 22px;
  background: linear-gradient(160deg, #dff6f3, #ffffff);
  border: 1px solid rgba(25, 169, 161, 0.18);
}

.hero-illustration svg {
  width: min(100%, 360px);
  height: auto;
  filter: drop-shadow(0 20px 30px rgba(20, 50, 61, 0.12));
}

.hero-copy {
  display: grid;
  gap: 0.95rem;
  align-content: center;
}

.hero h1 {
  max-width: 780px;
  font-size: clamp(2.35rem, 7vw, 4.9rem);
  line-height: 0.95;
  letter-spacing: -0.06em;
  color: var(--navy);
}

.hero-text,
.muted,
.topic-quicktake,
.footer-note,
.explanation,
.review-card p,
.empty-state,
.plain-list {
  color: var(--muted);
  line-height: 1.55;
}

.hero-actions,
.button-row,
.flashcard-meta,
.quiz-toolbar,
.topic-card-head,
.result-row,
.section-heading,
.hero-stats,
.chip-row,
.metric-grid,
.trust-grid {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.trust-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.trust-card {
  display: grid;
  gap: 0.2rem;
  padding: 0.85rem;
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.78);
  border: 1px solid rgba(25, 169, 161, 0.18);
}

.trust-card strong {
  display: block;
  color: var(--navy);
  font-size: 0.95rem;
}

.trust-card span {
  display: block;
  color: var(--muted);
  font-size: 0.84rem;
}

.handbook-strip {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin: 1rem 0;
}

.stat-pill,
.metric-card,
.subcard,
.topic-card,
.review-card,
.coach-readiness-card,
.coach-action-card {
  padding: 1rem;
}

.stat-pill {
  border-radius: 20px;
  background: rgba(255, 255, 255, 0.78);
  border: 1px solid rgba(25, 169, 161, 0.16);
}

.stat-value,
.metric-value {
  display: block;
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: -0.03em;
}

.stat-label,
.metric-label,
.face-label,
.source-ref,
.field-label,
.eyebrow,
.tap-hint {
  color: var(--muted);
  font-size: 0.85rem;
}

.eyebrow {
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-weight: 700;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0.9rem 1.1rem;
  border-radius: 16px;
  text-decoration: none;
  transition: transform 120ms ease, opacity 120ms ease;
}

.button:hover {
  transform: translateY(-1px);
}

.button-dark {
  background: var(--teal);
  color: white;
  box-shadow: 0 12px 24px rgba(25, 169, 161, 0.24);
}

.button-light {
  background: var(--surface-alt);
  color: var(--text);
  border: 1px solid var(--line);
}

.button-success {
  background: var(--success);
  color: white;
}

.tab-bar {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  padding: 0.45rem;
  gap: 0.45rem;
}

.tab-button {
  min-height: 48px;
  border-radius: 16px;
  background: transparent;
  color: var(--muted);
  font-weight: 700;
}

.tab-button.active {
  background: var(--navy);
  color: white;
}

.grid {
  display: grid;
  gap: 1rem;
}

.grid-form {
  display: grid;
  gap: 0.85rem;
}

.topic-grid {
  display: grid;
  gap: 1rem;
}

.stack-sm,
.stack-md {
  display: grid;
  gap: 0.75rem;
}

.stack-md {
  gap: 1rem;
}

.section-heading {
  align-items: flex-end;
  justify-content: space-between;
  margin-bottom: 1rem;
}

.chip,
.mini-chip,
.timer-chip {
  display: inline-flex;
  align-items: center;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: var(--surface-alt);
  color: var(--text);
}

.chip,
.timer-chip {
  min-height: 40px;
  padding: 0.55rem 0.9rem;
}

.mini-chip {
  padding: 0.35rem 0.65rem;
  font-size: 0.82rem;
}

.timer-chip {
  font-weight: 700;
}

.chip.active {
  background: var(--teal);
  color: white;
  border-color: transparent;
}

.chip.static {
  cursor: default;
}

.mode-chip-row {
  margin-bottom: 1rem;
}

.bullet-list {
  display: grid;
  gap: 0.65rem;
  color: var(--muted);
}

.bullet-list.compact {
  gap: 0.55rem;
}

.plain-list {
  padding-left: 0;
}

.source-panel {
  display: grid;
  gap: 0.85rem;
}

.source-title {
  font-size: 1.15rem;
  font-weight: 800;
}

.text-link {
  color: var(--text);
  font-weight: 700;
}

.topic-card {
  display: grid;
  gap: 0.85rem;
}

.topic-card h3,
.quiz-question-card h3,
.subcard h3,
.results-block h3 {
  font-size: 1.15rem;
  line-height: 1.3;
}

.flashcard {
  width: 100%;
  padding: 1.35rem;
  min-height: 260px;
  text-align: left;
  display: flex;
  align-items: stretch;
  margin-top: 1rem;
}

.flashcard-face {
  display: grid;
  align-content: space-between;
  gap: 1rem;
  width: 100%;
}

.flashcard-face p {
  font-size: clamp(1.2rem, 4vw, 1.55rem);
  line-height: 1.35;
  font-weight: 700;
  letter-spacing: -0.03em;
}

.flashcard-face.back p {
  font-weight: 600;
}

.tap-hint {
  justify-self: start;
}

.compact {
  gap: 0.55rem;
}

.quiz-toolbar {
  justify-content: space-between;
  align-items: end;
  margin-bottom: 1rem;
}

.field-group {
  display: grid;
  gap: 0.45rem;
  min-width: min(100%, 220px);
}

.empty-state {
  border: 1px dashed rgba(17, 17, 17, 0.15);
  border-radius: 18px;
  padding: 1rem;
  text-align: center;
}

.quiz-question-card,
.results-panel {
  padding: 1.2rem;
  display: grid;
  gap: 1rem;
}

.option-list {
  display: grid;
  gap: 0.75rem;
}

.option-card {
  display: flex;
  align-items: flex-start;
  gap: 0.85rem;
  padding: 1rem;
  border-radius: 18px;
  border: 1px solid var(--line);
  background: var(--surface-alt);
}

.option-card.selected {
  border-color: rgba(17, 17, 17, 0.25);
}

.option-card.correct {
  background: var(--success-soft);
  border-color: rgba(31, 122, 65, 0.25);
}

.option-card.incorrect {
  background: var(--danger-soft);
  border-color: rgba(155, 28, 28, 0.2);
}

.option-card input {
  margin-top: 0.15rem;
}

.explanation {
  padding: 0.9rem 1rem;
  border-radius: 16px;
  background: var(--surface-alt);
  border: 1px solid var(--line);
  display: grid;
  gap: 0.5rem;
}

.quiz-feedback-status {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: fit-content;
  padding: 0.3rem 0.7rem;
  border-radius: 999px;
  font-weight: 800;
  letter-spacing: 0.01em;
}

.quiz-feedback-status.correct {
  background: var(--success-soft);
  color: var(--success);
}

.quiz-feedback-status.incorrect {
  background: var(--danger-soft);
  color: var(--danger);
}

.exam-outcome {
  display: grid;
  gap: 0.45rem;
  padding: 1rem;
  border-radius: 18px;
  border: 1px solid var(--line);
}

.exam-outcome.pass {
  background: var(--success-soft);
}

.exam-outcome.fail {
  background: var(--danger-soft);
}

.exam-outcome-badge {
  font-size: 1.1rem;
  font-weight: 800;
}

.exam-outcome-text {
  font-weight: 700;
}

.exam-outcome-subtext {
  color: var(--muted);
}

.metric-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.metric-grid.compact {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.progress-detail-grid {
  margin-top: 1rem;
}

.subcard {
  display: grid;
  gap: 0.9rem;
}

.result-row {
  justify-content: space-between;
  align-items: center;
  padding: 0.85rem 0.95rem;
  border-radius: 16px;
  background: var(--surface-alt);
  border: 1px solid var(--line);
}

.study-coach-section {
  background: linear-gradient(135deg, #ffffff 0%, #f8f8f7 58%, #eef7f0 100%);
}

.study-coach-grid {
  display: grid;
  gap: 1rem;
}

.coach-readiness-card,
.coach-action-card {
  display: grid;
  gap: 0.85rem;
  border: 1px solid var(--line);
}

.readiness-score {
  display: block;
  font-size: clamp(2.5rem, 9vw, 4.5rem);
  line-height: 0.95;
  font-weight: 900;
  letter-spacing: -0.07em;
}

.readiness-meter {
  height: 12px;
  overflow: hidden;
  border-radius: 999px;
  background: rgba(17, 17, 17, 0.08);
}

.readiness-meter span {
  display: block;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--success), #66c77a);
}

.compact-row {
  padding: 0.65rem 0.75rem;
}

.coach-action {
  display: grid;
  gap: 0.2rem;
  width: 100%;
  text-align: left;
  padding: 0.9rem 1rem;
  border-radius: 16px;
  background: var(--surface-alt);
  border: 1px solid var(--line);
  color: var(--text);
}

.coach-action span {
  color: var(--muted);
  font-size: 0.92rem;
}

.review-card {
  display: grid;
  gap: 0.45rem;
}

.results-block {
  display: grid;
  gap: 0.85rem;
}

.footer-note {
  text-align: center;
  padding: 0.5rem 0 0.75rem;
}

.hidden {
  display: none !important;
}

@media (min-width: 760px) {
  .hero {
    grid-template-columns: 0.9fr 1.35fr;
    align-items: stretch;
  }

  .two-up {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .topic-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .metric-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .study-coach-grid {
    grid-template-columns: 1.1fr 1fr 1fr;
  }

  .grid-form {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (max-width: 759px) {
  .tab-bar {
    position: sticky;
    top: max(0.5rem, env(safe-area-inset-top));
    z-index: 10;
  }

  .tab-bar,
  .hero,
  .card,
  .topic-card,
  .flashcard,
  .quiz-question-card,
  .results-panel,
  .subcard,
  .coach-readiness-card,
  .coach-action-card {
    border-radius: 22px;
  }

  .tab-button {
    font-size: 0.92rem;
  }

  .hero-actions .button,
  .button-row .button,
  .mobile-wrap .button {
    flex: 1 1 100%;
  }

  .button-row {
    display: flex;
    flex-direction: column;
  }

  .section-heading {
    align-items: flex-start;
  }

  .hero-stats,
  .metric-grid,
  .metric-grid.compact,
  .trust-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .field-group {
    min-width: 100%;
  }
}