:root {
  color-scheme: dark;
  font-family:
    Inter,
    ui-sans-serif,
    system-ui,
    -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    sans-serif;
  --ink: #f5f7fb;
  --muted: #9cabc0;
  --panel: #101a2b;
  --panel-light: #17243a;
  --line: #2c3b55;
  --cyan: #53d9e8;
  --cyan-dark: #102f3c;
  --gold: #f4c95d;
  --red: #ff7284;
  --red-dark: #361b2a;
  --green: #62e6a6;
  --green-dark: #15352d;
}

* {
  box-sizing: border-box;
}

html,
body {
  min-width: 320px;
  min-height: 100%;
  margin: 0;
  background:
    radial-gradient(circle at 90% 0%, rgb(43 100 123 / 24%), transparent 34rem),
    #08101e;
  color: var(--ink);
}

body {
  min-height: 100vh;
}

button {
  font: inherit;
}

.app-shell {
  width: min(1100px, 100%);
  min-height: 100vh;
  margin: 0 auto;
  padding: clamp(1.25rem, 3.5vw, 2.75rem);
}

.lab-header {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: start;
  gap: 2rem;
  margin-bottom: clamp(1.4rem, 3vw, 2.4rem);
}

.eyebrow,
.round-label,
.feedback-kicker {
  margin: 0 0 0.45rem;
  color: var(--cyan);
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

h1,
h2,
p {
  margin-top: 0;
}

h1 {
  margin-bottom: 0.55rem;
  font-size: clamp(2.1rem, 6vw, 4.3rem);
  line-height: 0.98;
  letter-spacing: -0.055em;
}

.lab-intro {
  max-width: 44rem;
  margin-bottom: 0;
  color: var(--muted);
  font-size: clamp(0.95rem, 1.6vw, 1.08rem);
  line-height: 1.6;
}

.progress {
  min-width: 7.6rem;
  padding: 0.85rem 1rem 0.9rem;
  border: 1px solid var(--line);
  background: rgb(16 26 43 / 78%);
  box-shadow: 0.4rem 0.4rem 0 #050a13;
}

.progress > span {
  display: block;
  margin-bottom: 0.25rem;
  color: var(--muted);
  font-size: 0.7rem;
  font-weight: 800;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.progress strong {
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  font-size: 1.55rem;
}

.progress small {
  color: var(--muted);
  font-size: 0.82rem;
  font-weight: 500;
}

.round-heading {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 0.9rem;
}

.round-heading h2 {
  margin: 0;
  font-size: clamp(1.18rem, 2.4vw, 1.65rem);
}

.score {
  margin: 0;
  color: var(--muted);
  white-space: nowrap;
}

.score span {
  color: var(--gold);
  font-weight: 800;
}

.choices {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 1rem;
}

.choice-card {
  min-width: 0;
  min-height: 10.25rem;
  padding: 1.1rem;
  border: 1px solid var(--line);
  border-radius: 0;
  background: linear-gradient(145deg, var(--panel-light), var(--panel));
  box-shadow: 0.45rem 0.45rem 0 #050a13;
  color: var(--ink);
  cursor: pointer;
  text-align: left;
  transition:
    border-color 150ms ease,
    background 150ms ease,
    transform 150ms ease;
}

.choice-card:hover:not(:disabled) {
  border-color: var(--cyan);
  background: linear-gradient(145deg, #1b3045, #122235);
  transform: translateY(-2px);
}

.choice-card:focus-visible,
.primary-action:focus-visible,
.secondary-action:focus-visible {
  outline: 3px solid var(--gold);
  outline-offset: 3px;
}

.choice-card:disabled {
  cursor: default;
  opacity: 1;
}

.choice-heading {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 2.25rem;
}

.choice-label {
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.choice-badge {
  padding: 0.3rem 0.45rem;
  border: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.66rem;
  font-weight: 750;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.choice-card code {
  display: block;
  overflow-wrap: anywhere;
  color: var(--ink);
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  font-size: clamp(0.8rem, 1.5vw, 1rem);
  font-weight: 700;
  line-height: 1.75;
  letter-spacing: 0.045em;
}

.choice-card.is-correct {
  border-color: var(--green);
  background: linear-gradient(145deg, var(--green-dark), #10251f);
}

.choice-card.is-correct .choice-badge {
  border-color: var(--green);
  color: var(--green);
}

.choice-card.is-ciphertext {
  opacity: 0.68;
}

.choice-card.is-wrong {
  border-color: var(--red);
  background: linear-gradient(145deg, var(--red-dark), #241421);
}

.choice-card.is-wrong .choice-badge {
  border-color: var(--red);
  color: var(--red);
}

.versus {
  position: absolute;
  z-index: 2;
  top: 50%;
  left: 50%;
  display: grid;
  width: 2.2rem;
  height: 2.2rem;
  place-items: center;
  border: 1px solid var(--line);
  background: #08101e;
  color: var(--muted);
  font-size: 0.68rem;
  font-weight: 800;
  text-transform: uppercase;
  transform: translate(-50%, -50%);
}

.hint,
.feedback {
  display: grid;
  align-items: center;
  gap: 1rem;
  margin-top: 1rem;
  border: 1px solid var(--line);
  background: rgb(16 26 43 / 82%);
}

.hint {
  grid-template-columns: auto 1fr;
  padding: 1rem 1.1rem;
}

.hint p,
.feedback p {
  margin-bottom: 0;
  color: var(--muted);
  line-height: 1.5;
}

.hint strong {
  color: var(--ink);
}

.hint-icon {
  display: grid;
  width: 1.8rem;
  height: 1.8rem;
  place-items: center;
  border: 1px solid var(--cyan);
  color: var(--cyan);
  font-family: Georgia, serif;
  font-weight: 800;
}

.feedback {
  grid-template-columns: minmax(0, 1.35fr) minmax(15rem, 1fr) auto;
  padding: 1rem;
}

.feedback h2 {
  margin-bottom: 0.25rem;
  font-size: 1.05rem;
}

.feedback.is-success {
  border-color: #287657;
  background: rgb(19 48 40 / 88%);
}

.feedback.is-error {
  grid-template-columns: 1fr auto;
  border-color: #7b3042;
  background: rgb(52 25 39 / 90%);
}

.feedback.is-error .feedback-kicker {
  color: var(--red);
}

.reveal {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.65rem;
}

.reveal span {
  min-width: 0;
  padding: 0.65rem 0.75rem;
  background: rgb(5 16 15 / 48%);
}

.reveal small {
  display: block;
  margin-bottom: 0.3rem;
  color: #8fb9aa;
  font-size: 0.62rem;
  font-weight: 800;
  letter-spacing: 0.09em;
  text-transform: uppercase;
}

.reveal code,
.reveal strong {
  display: block;
  overflow: hidden;
  color: var(--green);
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  font-size: 0.8rem;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.primary-action,
.secondary-action {
  min-height: 2.8rem;
  padding: 0.7rem 0.9rem;
  border-radius: 0;
  cursor: pointer;
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.04em;
  white-space: nowrap;
}

.primary-action {
  border: 1px solid var(--cyan);
  background: var(--cyan);
  color: #07131a;
}

.primary-action:hover {
  background: #91edf5;
}

.secondary-action {
  border: 1px solid var(--red);
  background: transparent;
  color: var(--red);
}

.secondary-action:hover {
  background: var(--red-dark);
}

.results-card,
.loading-card {
  width: min(42rem, 100%);
  margin: clamp(3rem, 12vh, 8rem) auto 0;
  padding: clamp(1.4rem, 4vw, 2.5rem);
  border: 1px solid var(--line);
  background: rgb(16 26 43 / 90%);
  box-shadow: 0.65rem 0.65rem 0 #050a13;
}

.results-card h1,
.loading-card h1 {
  font-size: clamp(2rem, 6vw, 3.6rem);
}

.results-card > p:not(.eyebrow),
.loading-card > p:not(.eyebrow) {
  color: var(--muted);
  line-height: 1.65;
}

.results-card dl {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  margin: 1.5rem 0;
  background: var(--line);
}

.results-card dl div {
  padding: 1rem;
  background: var(--panel);
}

.results-card dt {
  color: var(--muted);
  font-size: 0.7rem;
  font-weight: 800;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.results-card dd {
  margin: 0.3rem 0 0;
  color: var(--gold);
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 1.4rem;
  font-weight: 800;
}

.loading-card {
  display: grid;
  justify-items: center;
  text-align: center;
}

.loading-mark {
  width: 2.2rem;
  height: 2.2rem;
  margin-bottom: 1rem;
  border: 2px solid var(--line);
  border-top-color: var(--cyan);
  animation: spin 800ms linear infinite;
}

.loading-card p {
  margin-bottom: 0;
}

.error-card {
  justify-items: start;
  text-align: left;
}

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

@media (max-width: 780px) {
  .app-shell {
    padding: 1.25rem;
  }

  .lab-header {
    grid-template-columns: 1fr;
    gap: 1rem;
  }

  .progress {
    min-width: 0;
    width: fit-content;
  }

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

  .versus {
    top: 50%;
  }

  .feedback,
  .feedback.is-error {
    grid-template-columns: 1fr;
  }

  .primary-action,
  .secondary-action {
    width: 100%;
  }
}

@media (max-width: 480px) {
  .round-heading {
    display: block;
  }

  .score {
    margin-top: 0.45rem;
  }

  .choice-card {
    min-height: 8.5rem;
  }

  .choice-heading {
    margin-bottom: 1.3rem;
  }

  .reveal,
  .results-card dl {
    grid-template-columns: 1fr;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition: none !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }
}