:root {
  color-scheme: light;
  --ink: #142943;
  --muted: #637181;
  --line: #d7e1e6;
  --surface: #ffffff;
  --soft: #f3f7f9;
  --navy: #17345a;
  --teal: #078c8c;
  --blue: #1f6f9f;
  --orange: #f08a20;
  --green: #2f9861;
  --red: #c64747;
  --shadow: 0 18px 46px rgba(20, 41, 67, 0.13);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  min-height: 100vh;
  margin: 0;
  color: var(--ink);
  background: linear-gradient(180deg, #f8fbfd 0%, #eaf2f4 100%);
}

button,
input {
  font: inherit;
}

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

h1 {
  max-width: 820px;
  font-size: clamp(1.5rem, 3vw, 2.55rem);
  line-height: 1.08;
  letter-spacing: 0;
}

h2 {
  font-size: 1.2rem;
  line-height: 1.2;
  letter-spacing: 0;
}

h3 {
  font-size: 1rem;
  line-height: 1.25;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 5;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 22px;
  padding: 20px clamp(18px, 4vw, 48px);
  border-bottom: 1px solid var(--line);
  background: rgba(248, 251, 253, 0.94);
  backdrop-filter: blur(14px);
}

.eyebrow {
  margin-bottom: 7px;
  color: var(--teal);
  font-size: 0.72rem;
  font-weight: 900;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.tabs {
  display: grid;
  grid-template-columns: repeat(5, minmax(92px, 1fr));
  gap: 4px;
  padding: 4px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
}

.tab,
.text-button,
.icon-button {
  min-height: 38px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  color: var(--ink);
  font-weight: 850;
  cursor: pointer;
}

.tab {
  border: 0;
  padding: 0 12px;
  color: var(--muted);
}

.tab.is-active {
  background: var(--navy);
  color: #fff;
}

.text-button {
  padding: 0 14px;
}

.text-button.primary {
  border-color: var(--teal);
  background: var(--teal);
  color: #fff;
}

.install-button[hidden] {
  display: none;
}

.icon-button {
  display: inline-grid;
  place-items: center;
  width: 38px;
  padding: 0;
}

main {
  padding: 28px clamp(18px, 4vw, 48px) 44px;
}

.view {
  display: none;
}

.view.is-active {
  display: block;
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(300px, 390px);
  gap: 20px;
  align-items: stretch;
  margin-bottom: 20px;
}

.hero-copy,
.priority-panel,
.theme-card,
.section-bar,
.source-graphic,
.mini-card,
.flashcard,
.question-card,
.evidence-card {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  box-shadow: var(--shadow);
}

.hero-copy {
  display: grid;
  gap: 18px;
  padding: clamp(22px, 4vw, 42px);
}

.hero-copy > p,
.priority-panel p,
.theme-card p,
.mini-card p,
.evidence-card p,
.question-card p {
  color: var(--muted);
  line-height: 1.55;
}

.priority-panel {
  display: grid;
  align-content: start;
  gap: 14px;
  padding: 22px;
}

.metric-row {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
}

.metric-row div {
  min-height: 94px;
  padding: 14px;
  border-radius: 8px;
  background: var(--soft);
}

.metric-row strong {
  display: block;
  color: var(--orange);
  font-size: 2.1rem;
  line-height: 1;
}

.metric-row span {
  display: block;
  margin-top: 8px;
  color: var(--muted);
  font-size: 0.86rem;
  font-weight: 750;
}

.theme-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
}

.theme-card {
  display: grid;
  gap: 10px;
  padding: 16px;
  box-shadow: none;
}

.theme-card .number {
  display: grid;
  place-items: center;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: color-mix(in srgb, var(--accent) 16%, #fff);
  color: var(--accent);
  font-weight: 950;
}

.section-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 18px;
  padding: 18px;
}

.search {
  display: grid;
  gap: 6px;
  min-width: min(360px, 100%);
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 900;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.search input {
  min-height: 42px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 0 12px;
  color: var(--ink);
  letter-spacing: 0;
  text-transform: none;
}

.infograph-layout {
  display: grid;
  grid-template-columns: minmax(0, 0.95fr) minmax(360px, 1.05fr);
  gap: 18px;
  align-items: start;
}

.source-graphic {
  overflow: hidden;
}

.source-graphic img {
  display: block;
  width: 100%;
  height: auto;
}

.mini-graphics {
  display: grid;
  gap: 14px;
}

.mini-card {
  display: grid;
  grid-template-columns: 74px 1fr;
  gap: 14px;
  padding: 16px;
}

.mini-icon {
  display: grid;
  place-items: center;
  width: 72px;
  height: 72px;
  border-radius: 50%;
  background: color-mix(in srgb, var(--accent) 14%, #fff);
  color: var(--accent);
  font-size: 1.4rem;
  font-weight: 950;
}

.mini-card div:last-child {
  display: grid;
  gap: 8px;
}

.mini-card ul {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  padding: 0;
  margin: 0;
  list-style: none;
}

.mini-card li {
  padding: 5px 8px;
  border-radius: 999px;
  background: var(--soft);
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 850;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.flashcard {
  display: grid;
  align-content: center;
  min-height: 370px;
  max-width: 880px;
  margin: 0 auto 14px;
  padding: clamp(24px, 5vw, 54px);
  cursor: pointer;
}

.flashcard .face {
  display: grid;
  gap: 16px;
}

.flashcard .label {
  color: var(--teal);
  font-size: 0.78rem;
  font-weight: 950;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.flashcard .prompt {
  font-size: clamp(1.35rem, 3vw, 2.1rem);
  line-height: 1.18;
  font-weight: 900;
}

.flashcard .answer {
  color: var(--muted);
  font-size: 1.06rem;
  line-height: 1.65;
}

.progress-track {
  max-width: 880px;
  height: 10px;
  margin: 0 auto;
  overflow: hidden;
  border-radius: 999px;
  background: #dfe8eb;
}

.progress-track div {
  height: 100%;
  width: 0;
  border-radius: inherit;
  background: var(--teal);
}

.score-pill {
  display: inline-grid;
  place-items: center;
  min-height: 38px;
  padding: 0 14px;
  border-radius: 999px;
  background: var(--soft);
  color: var(--muted);
  font-weight: 950;
}

.exam-form,
.evidence-grid {
  display: grid;
  gap: 14px;
}

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

.question-card,
.evidence-card {
  display: grid;
  gap: 12px;
  padding: 18px;
  box-shadow: none;
}

.question-card fieldset {
  display: grid;
  gap: 8px;
  padding: 0;
  margin: 0;
  border: 0;
}

.question-card legend {
  padding: 0;
  font-weight: 900;
  line-height: 1.35;
}

.choice {
  display: grid;
  grid-template-columns: 18px 1fr;
  gap: 10px;
  align-items: start;
  padding: 11px 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--soft);
  color: var(--muted);
  cursor: pointer;
}

.choice input {
  margin-top: 3px;
}

.rationale {
  display: none;
  padding: 12px;
  border-radius: 8px;
  background: #ecf6f4;
  color: var(--muted);
  line-height: 1.5;
}

.question-card.is-scored .rationale {
  display: block;
}

.question-card.correct {
  border-color: color-mix(in srgb, var(--green) 55%, #fff);
}

.question-card.incorrect {
  border-color: color-mix(in srgb, var(--red) 55%, #fff);
}

.exam-actions {
  margin-top: 18px;
}

.evidence-card .tag {
  color: var(--teal);
  font-size: 0.78rem;
  font-weight: 950;
}

.evidence-card cite {
  color: var(--ink);
  font-style: normal;
  font-weight: 900;
  line-height: 1.35;
}

.source-link {
  justify-self: start;
  color: var(--blue);
  font-weight: 900;
  text-decoration: none;
}

.source-link:hover {
  text-decoration: underline;
}

.image-dialog {
  width: min(980px, calc(100vw - 32px));
  max-height: calc(100vh - 32px);
  padding: 0;
  border: 0;
  border-radius: 8px;
  background: #fff;
  box-shadow: 0 24px 80px rgba(0, 0, 0, 0.35);
}

.image-dialog::backdrop {
  background: rgba(10, 20, 34, 0.74);
}

.image-dialog img {
  display: block;
  width: 100%;
  height: auto;
}

.image-dialog .close {
  position: absolute;
  top: 10px;
  right: 10px;
}

@media (max-width: 1160px) {
  .topbar,
  .section-bar {
    align-items: stretch;
    flex-direction: column;
  }

  .install-button {
    width: 100%;
  }

  .hero-grid,
  .infograph-layout {
    grid-template-columns: 1fr;
  }

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

@media (max-width: 760px) {
  .tabs {
    width: 100%;
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .metric-row,
  .theme-grid,
  .evidence-grid {
    grid-template-columns: 1fr;
  }

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