:root {
  --font-body: "Satoshi", "Inter", sans-serif;
  --font-display: "Cabinet Grotesk", "Satoshi", sans-serif;
  --text-xs: clamp(0.75rem, 0.7rem + 0.25vw, 0.875rem);
  --text-sm: clamp(0.875rem, 0.8rem + 0.35vw, 1rem);
  --text-base: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
  --text-lg: clamp(1.125rem, 1rem + 0.75vw, 1.5rem);
  --text-xl: clamp(1.5rem, 1.2rem + 1.25vw, 2.25rem);
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-full: 999px;
  --transition: 180ms cubic-bezier(0.16, 1, 0.3, 1);
}

:root,
[data-theme="light"] {
  --color-bg: #eef5f4;
  --color-surface: #f8fbfa;
  --color-surface-2: #ffffff;
  --color-surface-offset: #e2eeec;
  --color-border: #c7d8d5;
  --color-text: #18302f;
  --color-muted: #637572;
  --color-faint: #8fa09d;
  --color-primary: #056a72;
  --color-primary-hover: #074e55;
  --color-primary-soft: #d6eeee;
  --color-warning: #9a4f18;
  --color-error: #a13544;
  --color-success: #356f3a;
  --shadow-sm: 0 1px 2px rgba(14, 49, 47, 0.06);
  --shadow-md: 0 10px 30px rgba(14, 49, 47, 0.1);
}

[data-theme="dark"] {
  --color-bg: #101819;
  --color-surface: #162223;
  --color-surface-2: #1c2b2c;
  --color-surface-offset: #213334;
  --color-border: #314648;
  --color-text: #dbe8e6;
  --color-muted: #94a7a4;
  --color-faint: #708582;
  --color-primary: #63c1c8;
  --color-primary-hover: #8ad7dc;
  --color-primary-soft: #203b3e;
  --color-warning: #e1a063;
  --color-error: #e47885;
  --color-success: #88c987;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.25);
  --shadow-md: 0 10px 32px rgba(0, 0, 0, 0.32);
}

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

* {
  min-width: 0;
}

html {
  -webkit-text-size-adjust: none;
  text-size-adjust: none;
  scroll-behavior: smooth;
}

body {
  min-height: 100dvh;
  font-family: var(--font-body);
  font-size: var(--text-base);
  line-height: 1.55;
  color: var(--color-text);
  background: var(--color-bg);
  overflow-x: hidden;
}

button,
input,
select {
  font: inherit;
  color: inherit;
}

button,
select {
  cursor: pointer;
}

button,
input,
select,
a {
  transition:
    border-color var(--transition),
    background var(--transition),
    color var(--transition),
    box-shadow var(--transition),
    transform var(--transition);
}

:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 3px;
}

.skip-link {
  position: fixed;
  top: var(--space-3);
  left: var(--space-3);
  z-index: 10;
  transform: translateY(-150%);
  background: var(--color-primary);
  color: white;
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-md);
}

.skip-link:focus {
  transform: translateY(0);
}

.app-shell {
  display: grid;
  grid-template-columns: 286px minmax(0, 1fr);
  min-height: 100dvh;
  max-width: 100vw;
  overflow-x: hidden;
}

body[data-current-view="home"] .app-shell {
  grid-template-columns: minmax(0, 1fr);
}

body[data-current-view="home"] .sidebar {
  display: none;
}

.sidebar {
  position: sticky;
  top: 0;
  height: 100dvh;
  display: flex;
  flex-direction: column;
  gap: var(--space-8);
  padding: var(--space-6);
  border-right: 1px solid var(--color-border);
  background: color-mix(in srgb, var(--color-surface) 92%, transparent);
}

.brand {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.brand-mark {
  width: 44px;
  height: 44px;
  color: var(--color-primary);
  fill: none;
  stroke: currentColor;
  stroke-width: 2.6;
  stroke-linecap: round;
  stroke-linejoin: round;
  flex: 0 0 auto;
}

.brand strong {
  display: block;
  font-family: var(--font-display);
  font-size: var(--text-lg);
  line-height: 1.1;
}

.brand span,
.eyebrow,
.stat-label,
.score-label,
.card-kicker {
  display: block;
  color: var(--color-muted);
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.primary-nav {
  display: grid;
  gap: var(--space-2);
}

.nav-button,
.theme-toggle,
button,
select {
  border: 1px solid var(--color-border);
  background: var(--color-surface-2);
  border-radius: var(--radius-md);
}

.nav-button {
  min-height: 44px;
  text-align: left;
  padding: var(--space-3) var(--space-4);
  color: var(--color-muted);
}

.nav-button:hover,
.nav-button.active {
  color: var(--color-text);
  background: var(--color-primary-soft);
  border-color: color-mix(in srgb, var(--color-primary) 45%, var(--color-border));
}

.sidebar-footer {
  margin-top: auto;
}

.theme-toggle {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  min-height: 44px;
  width: 100%;
  padding: var(--space-3) var(--space-4);
}

.main {
  width: min(100%, 1440px);
  padding: var(--space-8);
}

body[data-current-view="home"] .main {
  width: min(100%, 1280px);
  margin-inline: auto;
  padding: clamp(var(--space-5), 4vw, var(--space-12));
}

.topbar {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(280px, 520px);
  gap: var(--space-8);
  align-items: end;
  margin-bottom: var(--space-8);
}

h1,
h2,
h3 {
  font-family: var(--font-display);
  line-height: 1.12;
  text-wrap: balance;
}

h1 {
  font-size: var(--text-xl);
}

h2 {
  font-size: var(--text-lg);
}

h3 {
  font-size: var(--text-base);
}

.search-wrap {
  display: grid;
  gap: var(--space-2);
}

.search-wrap label {
  color: var(--color-muted);
  font-size: var(--text-xs);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

input,
select {
  min-height: 44px;
  width: 100%;
  padding: var(--space-3) var(--space-4);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-surface-2);
}

.stats-grid {
  display: none;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: var(--space-4);
  margin-bottom: var(--space-6);
}

body[data-current-view="dashboard"] .stats-grid {
  display: grid;
}

.stat-card,
.notice,
.reader,
.flashcard,
.trainer-panel,
.quiz-card,
.score-panel,
.source-card {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background: var(--color-surface);
  box-shadow: var(--shadow-sm);
}

.stat-card {
  padding: var(--space-5);
}

.stat-value,
.score-value {
  display: block;
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: 700;
  line-height: 1;
}

.notice {
  display: none;
  gap: var(--space-2);
  align-items: baseline;
  margin-bottom: var(--space-8);
  padding: var(--space-4) var(--space-5);
  color: var(--color-warning);
  background: color-mix(in srgb, var(--color-warning) 12%, var(--color-surface));
}

.notice.visible {
  display: flex;
}

body[data-current-view="home"] .topbar {
  grid-template-columns: 1fr;
}

body[data-current-view="home"] .search-wrap,
body[data-current-view="home"] #blank-notice {
  display: none;
}

.view {
  display: none;
}

.view.active {
  display: block;
}

.license-hero {
  min-height: 320px;
  display: grid;
  align-items: end;
  margin-bottom: var(--space-6);
  padding: var(--space-10);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  background:
    radial-gradient(circle at top right, color-mix(in srgb, var(--color-primary) 18%, transparent), transparent 42%),
    linear-gradient(135deg, color-mix(in srgb, var(--color-primary) 8%, transparent), transparent),
    var(--color-surface-2);
  box-shadow: var(--shadow-sm);
}

.license-hero h2 {
  max-width: 820px;
  margin-block: var(--space-2) var(--space-4);
  font-size: clamp(2.25rem, 4.8vw, 5.5rem);
  letter-spacing: -0.055em;
}

.license-hero p {
  max-width: 76ch;
  color: var(--color-muted);
  font-size: var(--text-lg);
}

.license-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--space-4);
}

.license-card {
  min-height: 260px;
  display: grid;
  align-content: start;
  gap: var(--space-3);
  padding: var(--space-6);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  background: var(--color-surface-2);
  box-shadow: var(--shadow-sm);
}

.license-card.available {
  border-color: color-mix(in srgb, var(--color-primary) 42%, var(--color-border));
  background:
    linear-gradient(180deg, color-mix(in srgb, var(--color-primary) 9%, transparent), transparent 55%),
    var(--color-surface-2);
}

.license-card.coming-soon {
  opacity: 0.78;
}

.license-card h3 {
  font-size: var(--text-xl);
  letter-spacing: -0.025em;
}

.license-card p {
  color: var(--color-muted);
}

.license-card button {
  width: fit-content;
  margin-top: auto;
}

.license-card button:disabled {
  cursor: not-allowed;
  opacity: 0.62;
  transform: none;
}

.landing-hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 340px;
  gap: var(--space-5);
  align-items: stretch;
  margin-bottom: var(--space-6);
}

.landing-copy,
.landing-panel,
.quick-card {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  background: var(--color-surface-2);
  box-shadow: var(--shadow-sm);
}

.landing-copy {
  padding: var(--space-10);
  background:
    radial-gradient(circle at top right, color-mix(in srgb, var(--color-primary) 16%, transparent), transparent 42%),
    var(--color-surface-2);
}

.landing-copy h2 {
  max-width: 760px;
  margin-block: var(--space-2) var(--space-4);
  font-size: clamp(2rem, 4vw, 4.75rem);
  letter-spacing: -0.045em;
}

.landing-copy p {
  max-width: 78ch;
  color: var(--color-muted);
  font-size: var(--text-lg);
}

.landing-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  margin-top: var(--space-6);
}

.landing-panel {
  display: grid;
  align-content: end;
  gap: var(--space-3);
  padding: var(--space-6);
  background:
    linear-gradient(160deg, color-mix(in srgb, var(--color-primary) 16%, transparent), transparent),
    var(--color-surface);
}

.landing-panel strong {
  display: block;
  font-family: var(--font-display);
  font-size: var(--text-lg);
  line-height: 1.1;
}

.landing-panel p,
.quick-card p {
  color: var(--color-muted);
}

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

.quick-card {
  display: grid;
  gap: var(--space-3);
  align-content: start;
  padding: var(--space-5);
}

.quick-card button {
  margin-top: var(--space-2);
  width: fit-content;
}

.view-header {
  display: flex;
  justify-content: space-between;
  gap: var(--space-4);
  align-items: end;
  margin-bottom: var(--space-5);
}

.view-header select {
  max-width: 240px;
}

.content-layout {
  display: grid;
  grid-template-columns: 360px minmax(0, 1fr);
  gap: var(--space-5);
  align-items: start;
}

.content-layout.focused {
  grid-template-columns: minmax(0, 1fr);
}

.content-layout.focused .document-list {
  display: none;
}

.document-list {
  display: grid;
  gap: var(--space-3);
  max-height: calc(100dvh - 312px);
  overflow: auto;
  padding-right: var(--space-1);
}

.doc-button {
  width: 100%;
  text-align: left;
  padding: var(--space-4);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background: var(--color-surface-2);
}

.doc-button:hover,
.doc-button.active {
  transform: translateY(-1px);
  border-color: color-mix(in srgb, var(--color-primary) 45%, var(--color-border));
  box-shadow: var(--shadow-md);
}

.doc-button strong {
  display: block;
  margin-bottom: var(--space-2);
}

.doc-meta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  align-items: center;
  color: var(--color-muted);
  font-size: var(--text-xs);
}

.badge {
  display: inline-flex;
  align-items: center;
  min-height: 24px;
  padding: 0 var(--space-2);
  border-radius: var(--radius-full);
  background: var(--color-primary-soft);
  color: var(--color-primary);
  font-size: var(--text-xs);
  font-weight: 700;
}

.badge.warning {
  color: var(--color-warning);
  background: color-mix(in srgb, var(--color-warning) 14%, var(--color-surface));
}

.reader {
  min-height: 560px;
  padding: var(--space-8);
  background: var(--color-surface-2);
}

.reader-header {
  display: flex;
  justify-content: space-between;
  gap: var(--space-5);
  margin-bottom: var(--space-6);
}

.reader-tools,
.reader-actions {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: var(--space-3);
  flex-wrap: wrap;
}

.reader-tools {
  flex-shrink: 0;
}

.reader-actions {
  display: contents;
}

.reader-header p {
  color: var(--color-muted);
  margin-top: var(--space-2);
  max-width: 72ch;
}

.pdf-link {
  white-space: nowrap;
  color: var(--color-primary);
  font-weight: 700;
}

.section-block {
  padding-block: var(--space-5);
  border-top: 1px solid var(--color-border);
}

.section-block h3 {
  margin-bottom: var(--space-3);
}

.section-block ul {
  display: grid;
  gap: var(--space-2);
  padding-left: var(--space-5);
}

.section-block li {
  max-width: 80ch;
}

.empty-state {
  display: grid;
  place-items: start;
  gap: var(--space-2);
  color: var(--color-muted);
}

.guide-empty {
  min-height: 360px;
  align-content: center;
}

.trainer-layout,
.quiz-layout,
.math-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 320px;
  gap: var(--space-5);
}

.flashcard {
  min-height: 360px;
  display: grid;
  place-items: center;
  padding: var(--space-8);
  text-align: center;
  background:
    linear-gradient(145deg, color-mix(in srgb, var(--color-primary) 8%, transparent), transparent),
    var(--color-surface-2);
}

.flashcard:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.card-face {
  max-width: 680px;
}

.card-face h3 {
  margin-block: var(--space-4);
  font-size: var(--text-lg);
}

.card-hint {
  color: var(--color-muted);
  font-size: var(--text-sm);
}

.trainer-panel,
.score-panel {
  padding: var(--space-5);
}

.button-row,
.controls-inline {
  display: flex;
  gap: var(--space-3);
  flex-wrap: wrap;
}

button,
.secondary {
  min-height: 44px;
  padding: var(--space-3) var(--space-4);
  font-weight: 700;
}

button:hover {
  border-color: var(--color-primary);
}

.deck-list {
  display: grid;
  gap: var(--space-2);
  margin-top: var(--space-5);
}

.deck-pill {
  justify-content: space-between;
  width: 100%;
  text-align: left;
}

.deck-pill.active {
  border-color: var(--color-primary);
  background: color-mix(in oklab, var(--color-primary-highlight) 74%, var(--color-surface-2));
  color: var(--color-primary);
}

.quiz-card {
  padding: var(--space-8);
  background: var(--color-surface-2);
}

.quiz-card h3 {
  margin-bottom: var(--space-5);
}

.math-card,
.formula-panel {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background: var(--color-surface-2);
  box-shadow: var(--shadow-sm);
}

.math-card {
  padding: var(--space-8);
}

.math-card h3 {
  margin-block: var(--space-2) var(--space-4);
  font-size: var(--text-lg);
}

.problem-text {
  max-width: 78ch;
  margin-bottom: var(--space-5);
}

.answer-form {
  display: grid;
  grid-template-columns: minmax(160px, 240px) auto auto;
  gap: var(--space-3);
  align-items: end;
  margin-block: var(--space-5);
}

.answer-form label {
  display: grid;
  gap: var(--space-2);
  color: var(--color-muted);
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.answer-form input {
  color: var(--color-text);
  font-size: var(--text-base);
  font-weight: 700;
}

.math-feedback {
  min-height: 48px;
  padding: var(--space-4);
  border-radius: var(--radius-md);
  background: var(--color-surface-offset);
}

.math-feedback.correct {
  color: var(--color-success);
  background: color-mix(in srgb, var(--color-success) 12%, var(--color-surface));
}

.math-feedback.incorrect {
  color: var(--color-error);
  background: color-mix(in srgb, var(--color-error) 12%, var(--color-surface));
}

.worked-solution {
  display: none;
  margin-top: var(--space-5);
  padding-top: var(--space-5);
  border-top: 1px solid var(--color-border);
}

.worked-solution.visible {
  display: block;
}

.worked-solution ol {
  display: grid;
  gap: var(--space-2);
  padding-left: var(--space-5);
}

.formula-panel {
  padding: var(--space-5);
}

.formula-panel ul {
  display: grid;
  gap: var(--space-2);
  margin-top: var(--space-4);
  padding-left: var(--space-5);
}

.formula-note {
  color: var(--color-muted);
  font-size: var(--text-sm);
  margin-top: var(--space-5);
}

.choice-list {
  display: grid;
  gap: var(--space-3);
}

.choice {
  width: 100%;
  text-align: left;
  padding: var(--space-4);
  border-radius: var(--radius-md);
}

.choice.correct {
  border-color: var(--color-success);
  background: color-mix(in srgb, var(--color-success) 12%, var(--color-surface));
}

.choice.incorrect {
  border-color: var(--color-error);
  background: color-mix(in srgb, var(--color-error) 12%, var(--color-surface));
}

.explanation {
  margin-top: var(--space-5);
  padding: var(--space-4);
  border-radius: var(--radius-md);
  background: var(--color-surface-offset);
}

.score-panel p {
  color: var(--color-muted);
  margin-top: var(--space-4);
}

.source-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--space-4);
}

.source-card,
.exam-source-card {
  padding: var(--space-5);
  display: grid;
  gap: var(--space-3);
}

.source-card a,
.exam-source-card a {
  color: var(--color-primary);
  font-weight: 700;
}

.exam-source-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: var(--space-4);
}

.exam-source-card {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background: var(--color-surface);
  box-shadow: var(--shadow-sm);
}

.exam-source-card ul {
  display: grid;
  gap: var(--space-2);
  padding-left: var(--space-5);
}

.exam-additions {
  margin-top: var(--space-6);
  padding: var(--space-5);
  border: 1px solid color-mix(in srgb, var(--color-primary) 30%, var(--color-border));
  border-radius: var(--radius-lg);
  background: color-mix(in srgb, var(--color-primary) 7%, var(--color-surface));
}

.exam-additions h3 {
  margin-bottom: var(--space-3);
}

.exam-addition-card {
  display: grid;
  gap: var(--space-3);
  padding-block: var(--space-4);
  border-top: 1px solid var(--color-border);
}

.exam-addition-card:first-of-type {
  border-top: 0;
}

.exam-addition-card ul {
  display: grid;
  gap: var(--space-2);
  padding-left: var(--space-5);
}

mark {
  background: color-mix(in srgb, var(--color-primary) 24%, transparent);
  color: inherit;
  border-radius: var(--radius-sm);
}

@media (max-width: 980px) {
  .app-shell {
    grid-template-columns: 1fr;
  }

  .sidebar {
    position: static;
    height: auto;
    padding: var(--space-4);
    border-right: 0;
    border-bottom: 1px solid var(--color-border);
    overflow: hidden;
  }

  .primary-nav {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    overflow-x: visible;
    max-width: 100%;
  }

  .nav-button {
    width: 100%;
    white-space: nowrap;
  }

  .topbar,
  .content-layout,
  .trainer-layout,
  .quiz-layout,
  .math-layout,
  .landing-hero {
    grid-template-columns: 1fr;
  }

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

  .document-list {
    max-height: none;
  }
}

@media (max-width: 560px) {
  .main {
    padding: var(--space-4);
  }

  .stats-grid {
    grid-template-columns: 1fr;
  }

  .reader,
  .quiz-card,
  .flashcard,
  .math-card,
  .landing-copy {
    padding: var(--space-5);
  }

  .answer-form {
    grid-template-columns: 1fr;
  }

  .view-header,
  .reader-header {
    display: grid;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}