:root {
  --navy-950: #071b33;
  --navy-900: #0b2f5b;
  --blue-700: #1559b7;
  --blue-600: #1f6bd1;
  --blue-100: #e9f2ff;
  --blue-50: #f4f8ff;
  --ink-900: #152235;
  --ink-700: #44546a;
  --ink-500: #718096;
  --line: #dce5f0;
  --surface: #ffffff;
  --canvas: #f3f6fa;
  --accent: #ffcc4d;
  --accent-hover: #f3b920;
  --green: #16845b;
  --green-soft: #e9f8f1;
  --red: #c9414b;
  --red-soft: #fff0f1;
  --shadow: 0 16px 45px rgba(14, 42, 79, 0.1);
  --radius-lg: 24px;
  --radius-md: 16px;
  --radius-sm: 12px;
}

* {
  box-sizing: border-box;
}

html {
  min-height: 100%;
  background: var(--canvas);
}

body {
  min-width: 320px;
  min-height: 100vh;
  margin: 0;
  color: var(--ink-900);
  background:
    radial-gradient(circle at 90% 0%, rgba(31, 107, 209, 0.11), transparent 28rem),
    var(--canvas);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 16px;
  line-height: 1.5;
}

button,
input {
  font: inherit;
}

button {
  -webkit-tap-highlight-color: transparent;
}

.app-shell {
  width: min(1180px, calc(100% - 40px));
  margin: 0 auto;
  padding-bottom: 72px;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 92px;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  padding: 0;
  color: inherit;
  background: transparent;
  border: 0;
  cursor: pointer;
  text-align: left;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 48px;
  height: 48px;
  color: #fff;
  background: var(--navy-900);
  border-radius: 14px;
  box-shadow: 0 8px 20px rgba(11, 47, 91, 0.22);
  font-size: 0.88rem;
  font-weight: 900;
  letter-spacing: 0.06em;
}

.brand-copy {
  display: grid;
  line-height: 1.25;
}

.brand-copy strong {
  font-size: 1rem;
}

.brand-copy span {
  margin-top: 3px;
  color: var(--ink-500);
  font-size: 0.82rem;
}

.question-total,
.section-heading > span,
.quiz-counter {
  flex: none;
  padding: 8px 12px;
  color: var(--navy-900);
  background: var(--blue-100);
  border-radius: 999px;
  font-size: 0.82rem;
  font-weight: 750;
}

.screen {
  padding-top: 32px;
}

.is-hidden {
  display: none !important;
}

.loading-card,
.state-card {
  display: grid;
  justify-items: center;
  max-width: 520px;
  margin: 12vh auto 0;
  padding: 48px;
  text-align: center;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
}

.loading-card p {
  margin: 18px 0 0;
  color: var(--ink-700);
}

.spinner {
  width: 34px;
  height: 34px;
  border: 4px solid var(--blue-100);
  border-top-color: var(--blue-600);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

.state-icon {
  display: grid;
  place-items: center;
  width: 52px;
  height: 52px;
  color: var(--red);
  background: var(--red-soft);
  border-radius: 50%;
  font-size: 1.5rem;
  font-weight: 900;
}

.state-card h1 {
  margin: 22px 0 8px;
  font-size: clamp(1.5rem, 4vw, 2rem);
}

.state-card p {
  margin: 0 0 24px;
  color: var(--ink-700);
}

.home-intro {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 32px;
  margin-bottom: 28px;
}

.eyebrow,
.card-kicker,
.quiz-mode {
  margin: 0 0 7px;
  color: var(--blue-700);
  font-size: 0.76rem;
  font-weight: 850;
  letter-spacing: 0.11em;
  text-transform: uppercase;
}

.home-intro h1,
.section-heading h2,
.results-summary h1 {
  margin: 0;
  color: var(--navy-950);
  line-height: 1.12;
}

.home-intro h1 {
  font-size: clamp(2rem, 5vw, 3.35rem);
  letter-spacing: -0.045em;
}

.home-note {
  max-width: 300px;
  margin: 0 0 5px;
  color: var(--ink-700);
  text-align: right;
}

.simulation-card {
  position: relative;
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 28px;
  overflow: hidden;
  padding: 30px 34px;
  color: #fff;
  background:
    linear-gradient(120deg, rgba(255, 255, 255, 0.05), transparent 40%),
    var(--navy-900);
  border-radius: var(--radius-lg);
  box-shadow: 0 22px 50px rgba(7, 27, 51, 0.2);
}

.simulation-card::after {
  position: absolute;
  right: 18%;
  bottom: -125px;
  width: 260px;
  height: 260px;
  content: "";
  border: 45px solid rgba(255, 255, 255, 0.055);
  border-radius: 50%;
  pointer-events: none;
}

.simulation-number {
  position: relative;
  z-index: 1;
  display: grid;
  place-items: center;
  width: 92px;
  height: 92px;
  color: var(--navy-950);
  background: var(--accent);
  border-radius: 24px;
  font-size: 2.15rem;
  font-weight: 950;
  letter-spacing: -0.06em;
  transform: rotate(-3deg);
}

.simulation-copy {
  position: relative;
  z-index: 1;
}

.simulation-copy .card-kicker {
  color: var(--accent);
}

.simulation-copy h2 {
  margin: 0;
  font-size: clamp(1.35rem, 3vw, 1.85rem);
}

.simulation-copy p {
  margin: 8px 0 0;
  color: #cedcef;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  gap: 10px;
  padding: 11px 18px;
  border: 1px solid transparent;
  border-radius: 13px;
  font-weight: 800;
  cursor: pointer;
  transition: transform 150ms ease, box-shadow 150ms ease, background 150ms ease, border-color 150ms ease;
}

.button:hover:not(:disabled) {
  transform: translateY(-1px);
}

.button:focus-visible,
.brand:focus-visible,
.icon-button:focus-visible,
.module-card:focus-visible,
.option-label:has(input:focus-visible) {
  outline: 3px solid rgba(31, 107, 209, 0.3);
  outline-offset: 3px;
}

.button:disabled {
  cursor: not-allowed;
  opacity: 0.45;
}

.button--accent {
  position: relative;
  z-index: 1;
  color: var(--navy-950);
  background: var(--accent);
  box-shadow: 0 9px 24px rgba(255, 204, 77, 0.18);
}

.button--accent:hover {
  background: var(--accent-hover);
}

.button--primary {
  color: #fff;
  background: var(--blue-700);
  box-shadow: 0 8px 20px rgba(21, 89, 183, 0.18);
}

.button--primary:hover:not(:disabled) {
  background: var(--navy-900);
}

.button--secondary {
  color: var(--navy-900);
  background: var(--surface);
  border-color: var(--line);
}

.button--secondary:hover:not(:disabled) {
  border-color: #adc2dd;
  box-shadow: 0 7px 18px rgba(14, 42, 79, 0.07);
}

.section-heading {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 24px;
  margin: 54px 0 20px;
}

.section-heading h2 {
  font-size: clamp(1.45rem, 3vw, 2rem);
  letter-spacing: -0.025em;
}

.module-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.module-card {
  display: grid;
  grid-template-columns: auto 1fr;
  align-items: start;
  min-height: 174px;
  gap: 17px;
  padding: 22px;
  color: inherit;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  box-shadow: 0 4px 16px rgba(14, 42, 79, 0.035);
  cursor: pointer;
  text-align: left;
  transition: transform 160ms ease, box-shadow 160ms ease, border-color 160ms ease;
}

.module-card:hover {
  border-color: #a8c2e4;
  box-shadow: var(--shadow);
  transform: translateY(-3px);
}

.module-number {
  display: grid;
  place-items: center;
  min-width: 45px;
  height: 45px;
  padding: 0 9px;
  color: var(--blue-700);
  background: var(--blue-100);
  border-radius: 12px;
  font-size: 0.84rem;
  font-weight: 900;
}

.module-content {
  display: flex;
  min-width: 0;
  min-height: 126px;
  flex-direction: column;
}

.module-content h3 {
  margin: 1px 0 18px;
  font-size: 1rem;
  line-height: 1.38;
}

.module-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: auto;
  color: var(--ink-500);
  font-size: 0.84rem;
  font-weight: 650;
}

.module-arrow {
  color: var(--blue-700);
  font-size: 1.15rem;
}

.quiz-screen {
  width: min(840px, 100%);
  margin: 0 auto;
}

.quiz-toolbar {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 16px;
}

.icon-button {
  display: grid;
  place-items: center;
  width: 46px;
  height: 46px;
  color: var(--navy-900);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 13px;
  cursor: pointer;
  font-size: 1.35rem;
}

.quiz-title-wrap {
  min-width: 0;
}

.quiz-mode {
  margin-bottom: 2px;
  font-size: 0.7rem;
}

.quiz-title-wrap h1 {
  overflow: hidden;
  margin: 0;
  font-size: 1rem;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.progress-track {
  height: 7px;
  overflow: hidden;
  margin: 23px 0 20px;
  background: #dce7f5;
  border-radius: 999px;
}

.progress-fill {
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--blue-600), #42a4e8);
  border-radius: inherit;
  transition: width 230ms ease;
}

.question-card {
  padding: clamp(24px, 5vw, 44px);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
}

.question-meta {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 8px 16px;
  margin-bottom: 18px;
  color: var(--ink-500);
  font-size: 0.8rem;
  font-weight: 700;
}

.question-meta span:first-child {
  color: var(--blue-700);
}

.question-card h2 {
  margin: 0 0 28px;
  color: var(--navy-950);
  font-size: clamp(1.3rem, 3.4vw, 1.75rem);
  line-height: 1.38;
  letter-spacing: -0.018em;
}

.options-list {
  display: grid;
  gap: 12px;
  padding: 0;
  margin: 0;
  border: 0;
}

.option-label {
  display: grid;
  grid-template-columns: auto 1fr;
  align-items: start;
  gap: 14px;
  min-height: 58px;
  padding: 15px 17px;
  background: var(--blue-50);
  border: 1.5px solid transparent;
  border-radius: var(--radius-sm);
  cursor: pointer;
  line-height: 1.45;
  transition: background 140ms ease, border-color 140ms ease, transform 140ms ease;
}

.option-label:hover {
  border-color: #a9c8ed;
}

.option-label:has(input:checked) {
  background: #e6f0ff;
  border-color: var(--blue-600);
  transform: translateX(3px);
}

.option-label input {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  opacity: 0;
}

.option-letter {
  display: grid;
  place-items: center;
  width: 30px;
  height: 30px;
  color: var(--navy-900);
  background: #fff;
  border: 1px solid #c8d8eb;
  border-radius: 9px;
  font-size: 0.83rem;
  font-weight: 900;
  text-transform: uppercase;
}

.option-label:has(input:checked) .option-letter {
  color: #fff;
  background: var(--blue-700);
  border-color: var(--blue-700);
}

.option-text {
  padding-top: 3px;
}

.quiz-navigation {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 18px;
  margin-top: 20px;
}

.quiz-navigation .button:first-child {
  justify-self: start;
}

.quiz-navigation .button:last-child {
  justify-self: end;
}

.answered-status {
  color: var(--ink-500);
  font-size: 0.83rem;
  font-weight: 650;
  text-align: center;
}

.results-screen {
  width: min(940px, 100%);
  margin: 0 auto;
}

.results-hero {
  display: grid;
  grid-template-columns: auto 1fr;
  align-items: center;
  gap: 42px;
  padding: clamp(28px, 6vw, 52px);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
}

.score-ring {
  display: grid;
  place-items: center;
  width: 172px;
  height: 172px;
  padding: 14px;
  background: conic-gradient(var(--blue-600) 0%, #dfe8f3 0%);
  border-radius: 50%;
}

.score-ring > div {
  display: grid;
  place-items: center;
  width: 100%;
  height: 100%;
  align-content: center;
  background: #fff;
  border-radius: 50%;
}

.score-ring strong {
  color: var(--navy-950);
  font-size: 2.3rem;
  line-height: 1;
  letter-spacing: -0.055em;
}

.score-ring span {
  margin-top: 4px;
  color: var(--ink-500);
  font-size: 0.8rem;
  font-weight: 700;
}

.results-summary h1 {
  font-size: clamp(2rem, 4.5vw, 2.8rem);
  letter-spacing: -0.04em;
}

.results-summary > p:not(.eyebrow) {
  margin: 10px 0 24px;
  color: var(--ink-700);
}

.result-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  max-width: 480px;
  gap: 10px;
}

.stat {
  display: grid;
  padding: 12px 14px;
  background: var(--canvas);
  border-radius: 12px;
}

.stat strong {
  font-size: 1.25rem;
}

.stat span {
  color: var(--ink-500);
  font-size: 0.77rem;
  font-weight: 700;
}

.stat--correct strong {
  color: var(--green);
}

.stat--wrong strong {
  color: var(--red);
}

.result-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 24px;
}

.review-heading {
  margin-top: 48px;
}

.review-list {
  display: grid;
  gap: 16px;
}

.review-card {
  padding: 24px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
}

.review-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 8px 14px;
  margin-bottom: 12px;
  color: var(--ink-500);
  font-size: 0.78rem;
  font-weight: 750;
}

.review-index {
  color: var(--red);
}

.review-card h3 {
  margin: 0 0 18px;
  color: var(--navy-950);
  font-size: 1.05rem;
  line-height: 1.5;
}

.review-options {
  display: grid;
  gap: 8px;
}

.review-option {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: start;
  gap: 11px;
  padding: 11px 12px;
  color: var(--ink-700);
  background: var(--canvas);
  border: 1px solid transparent;
  border-radius: 10px;
}

.review-option .option-letter {
  width: 27px;
  height: 27px;
  font-size: 0.76rem;
}

.review-option.is-correct {
  color: #075a3b;
  background: var(--green-soft);
  border-color: #9bd5bd;
}

.review-option.is-selected-wrong {
  color: #982a34;
  background: var(--red-soft);
  border-color: #edb8bd;
}

.review-option.is-correct .option-letter {
  color: #fff;
  background: var(--green);
  border-color: var(--green);
}

.review-option.is-selected-wrong .option-letter {
  color: #fff;
  background: var(--red);
  border-color: var(--red);
}

.answer-badge {
  align-self: center;
  padding: 4px 7px;
  border-radius: 999px;
  font-size: 0.68rem;
  font-weight: 850;
  white-space: nowrap;
}

.answer-badge--correct {
  color: #075a3b;
  background: #c9ebdc;
}

.answer-badge--wrong {
  color: #982a34;
  background: #f7cfd3;
}

.blank-answer {
  margin: 12px 0 0;
  color: var(--red);
  font-size: 0.82rem;
  font-weight: 750;
}

.perfect-card {
  display: flex;
  align-items: center;
  gap: 18px;
  margin-top: 32px;
  padding: 24px;
  color: #075a3b;
  background: var(--green-soft);
  border: 1px solid #9bd5bd;
  border-radius: var(--radius-md);
}

.perfect-card > span {
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  flex: none;
  color: #fff;
  background: var(--green);
  border-radius: 50%;
  font-size: 1.3rem;
  font-weight: 900;
}

.perfect-card h2,
.perfect-card p {
  margin: 0;
}

.perfect-card h2 {
  font-size: 1.1rem;
}

.perfect-card p {
  margin-top: 4px;
  font-size: 0.9rem;
}

.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;
}

@media (max-width: 900px) {
  .module-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .simulation-card {
    grid-template-columns: auto 1fr;
  }

  .simulation-card .button {
    grid-column: 1 / -1;
    width: 100%;
  }
}

@media (max-width: 640px) {
  .app-shell {
    width: min(100% - 24px, 1180px);
    padding-bottom: 36px;
  }

  .topbar {
    min-height: 74px;
  }

  .brand-mark {
    width: 42px;
    height: 42px;
    border-radius: 12px;
  }

  .brand-copy span {
    display: none;
  }

  .question-total {
    font-size: 0.76rem;
  }

  .screen {
    padding-top: 20px;
  }

  .home-intro {
    display: block;
  }

  .home-note {
    margin-top: 12px;
    text-align: left;
  }

  .simulation-card {
    grid-template-columns: 1fr;
    gap: 19px;
    padding: 25px;
  }

  .simulation-number {
    width: 72px;
    height: 72px;
    border-radius: 19px;
    font-size: 1.7rem;
  }

  .simulation-card .button {
    grid-column: auto;
  }

  .section-heading {
    margin-top: 40px;
  }

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

  .module-card {
    min-height: 0;
  }

  .module-content {
    min-height: 112px;
  }

  .quiz-toolbar {
    gap: 11px;
  }

  .quiz-counter {
    padding: 7px 10px;
  }

  .question-card {
    padding: 23px 18px;
    border-radius: 18px;
  }

  .question-meta {
    display: grid;
  }

  .question-card h2 {
    margin-bottom: 22px;
  }

  .option-label {
    padding: 14px;
  }

  .quiz-navigation {
    position: sticky;
    bottom: 10px;
    z-index: 5;
    grid-template-columns: 1fr 1fr;
    gap: 10px;
    margin: 14px -2px 0;
    padding: 10px;
    background: rgba(243, 246, 250, 0.94);
    border: 1px solid rgba(220, 229, 240, 0.92);
    border-radius: 16px;
    box-shadow: 0 12px 26px rgba(14, 42, 79, 0.12);
    backdrop-filter: blur(12px);
  }

  .quiz-navigation .button {
    width: 100%;
  }

  .answered-status {
    grid-column: 1 / -1;
    grid-row: 1;
  }

  .quiz-navigation .button:first-child,
  .quiz-navigation .button:last-child {
    grid-row: 2;
  }

  .results-hero {
    grid-template-columns: 1fr;
    justify-items: center;
    gap: 27px;
    padding: 28px 20px;
    text-align: center;
  }

  .score-ring {
    width: 148px;
    height: 148px;
  }

  .result-stats {
    width: 100%;
  }

  .result-actions {
    justify-content: center;
  }

  .review-card {
    padding: 19px 16px;
  }

  .review-option {
    grid-template-columns: auto 1fr;
  }

  .answer-badge {
    grid-column: 2;
    justify-self: start;
  }
}

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