:root {
  color-scheme: light;
  --bg: #f4f6f8;
  --panel: #ffffff;
  --panel-2: #eef3f7;
  --text: #15202b;
  --muted: #657487;
  --line: #d8e0e8;
  --accent: #0f766e;
  --accent-2: #0b5f59;
  --danger: #b42318;
  --ok: #18794e;
  --warn: #b54708;
  --shadow: 0 18px 55px rgba(31, 41, 55, 0.12);
  --radius: 8px;
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    sans-serif;
}

[data-theme="dark"] {
  color-scheme: dark;
  --bg: #101418;
  --panel: #171d22;
  --panel-2: #202832;
  --text: #edf2f7;
  --muted: #a7b2c1;
  --line: #303a45;
  --accent: #2dd4bf;
  --accent-2: #14b8a6;
  --danger: #fb7185;
  --ok: #65d48d;
  --warn: #fbbf24;
  --shadow: 0 18px 55px rgba(0, 0, 0, 0.28);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--text);
}

button,
select,
input {
  font: inherit;
}

button {
  min-height: 42px;
  border: 0;
  border-radius: var(--radius);
  cursor: pointer;
  transition:
    transform 150ms ease,
    background 150ms ease,
    border-color 150ms ease;
}

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

button:disabled {
  cursor: not-allowed;
  opacity: 0.55;
  transform: none;
}

.app-shell {
  display: grid;
  grid-template-columns: 320px minmax(0, 1fr);
  min-height: 100vh;
}

.sidebar {
  display: flex;
  flex-direction: column;
  gap: 20px;
  padding: 24px;
  border-right: 1px solid var(--line);
  background: var(--panel);
}

.brand {
  display: flex;
  gap: 12px;
  align-items: center;
}

.brand-mark {
  display: grid;
  width: 42px;
  height: 42px;
  place-items: center;
  border-radius: var(--radius);
  background: var(--accent);
  color: #fff;
  font-weight: 800;
}

.brand h1,
.topbar h2,
.setup-panel h3 {
  margin: 0;
  letter-spacing: 0;
}

.brand h1 {
  font-size: 1.05rem;
}

.eyebrow {
  margin: 0 0 4px;
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 750;
  text-transform: uppercase;
}

.session-card,
.setup-panel,
.feedback-panel,
.result-summary,
.review-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel);
  box-shadow: var(--shadow);
}

.session-card {
  padding: 16px;
  box-shadow: none;
}

.session-row {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 10px;
  color: var(--muted);
  font-size: 0.92rem;
}

.session-row strong {
  color: var(--text);
}

.progress-track {
  height: 9px;
  overflow: hidden;
  border-radius: 999px;
  background: var(--panel-2);
}

.progress-bar {
  width: 0;
  height: 100%;
  background: var(--accent);
  transition: width 200ms ease;
}

.question-nav {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 8px;
  overflow: auto;
  padding-right: 2px;
}

.nav-dot {
  min-height: 38px;
  border: 1px solid var(--line);
  background: var(--panel-2);
  color: var(--text);
  font-weight: 700;
}

.nav-dot.current {
  border-color: var(--accent);
  background: color-mix(in srgb, var(--accent) 20%, var(--panel));
}

.nav-dot.correct {
  border-color: color-mix(in srgb, var(--ok) 65%, var(--line));
}

.nav-dot.wrong {
  border-color: color-mix(in srgb, var(--danger) 70%, var(--line));
}

.nav-dot.answered:not(.correct):not(.wrong) {
  background: color-mix(in srgb, var(--warn) 14%, var(--panel));
}

.sidebar-actions {
  display: flex;
  gap: 10px;
  margin-top: auto;
}

.icon-button {
  width: 46px;
  border: 1px solid var(--line);
  background: var(--panel-2);
  color: var(--text);
}

.ghost-button {
  border: 1px solid var(--line);
  background: var(--panel);
  color: var(--text);
  padding: 0 16px;
}

.primary-button {
  background: var(--accent);
  color: #03201d;
  font-weight: 800;
  padding: 0 18px;
}

[data-theme="light"] .primary-button,
:root:not([data-theme="dark"]) .primary-button {
  color: #fff;
}

.danger-button {
  border: 1px solid color-mix(in srgb, var(--danger) 50%, var(--line));
  background: color-mix(in srgb, var(--danger) 12%, var(--panel));
  color: var(--danger);
  font-weight: 800;
  padding: 0 16px;
}

.main-panel {
  min-width: 0;
  padding: 28px;
}

.view {
  display: none;
  max-width: 1100px;
  margin: 0 auto;
}

.view.active {
  display: block;
}

.topbar {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 18px;
  margin-bottom: 22px;
}

.topbar h2 {
  font-size: clamp(1.5rem, 2.4vw, 2.25rem);
  line-height: 1.1;
}

.setup-grid {
  display: grid;
  grid-template-columns: minmax(280px, 420px) 1fr;
  gap: 18px;
}

.setup-panel {
  padding: 20px;
}

.setup-panel h3 {
  margin-bottom: 16px;
  font-size: 1.05rem;
}

.field,
.check-row {
  display: grid;
  gap: 8px;
  margin-bottom: 14px;
  color: var(--muted);
  font-weight: 650;
}

.check-row {
  grid-template-columns: 18px 1fr;
  align-items: center;
}

select,
input[type="text"] {
  width: 100%;
  min-height: 44px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel-2);
  color: var(--text);
  padding: 0 12px;
}

.topic-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}

.topic-chip {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 12px;
  background: var(--panel-2);
  font-weight: 700;
}

.quiz-topbar {
  align-items: flex-start;
}

.pill-row {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 8px;
}

.pill {
  border: 1px solid color-mix(in srgb, var(--accent) 45%, var(--line));
  border-radius: 999px;
  padding: 7px 10px;
  background: color-mix(in srgb, var(--accent) 12%, var(--panel));
  color: var(--text);
  font-size: 0.82rem;
  font-weight: 800;
}

.pill.muted {
  border-color: var(--line);
  background: var(--panel-2);
  color: var(--muted);
}

.answer-area {
  display: grid;
  gap: 12px;
}

.answer-card {
  display: grid;
  grid-template-columns: 24px 1fr;
  gap: 12px;
  align-items: start;
  width: 100%;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 14px;
  background: var(--panel);
}

.answer-card input {
  margin-top: 4px;
}

.answer-card.selected {
  border-color: var(--accent);
  background: color-mix(in srgb, var(--accent) 10%, var(--panel));
}

.answer-card.correct {
  border-color: color-mix(in srgb, var(--ok) 70%, var(--line));
}

.answer-card.wrong {
  border-color: color-mix(in srgb, var(--danger) 72%, var(--line));
}

.answer-text {
  font-weight: 720;
  line-height: 1.45;
}

.answer-explanation {
  margin-top: 6px;
  color: var(--muted);
  font-size: 0.95rem;
  line-height: 1.45;
}

.fill-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 16px;
  background: var(--panel);
}

.feedback-panel {
  margin-top: 18px;
  padding: 18px;
}

.feedback-panel.correct {
  border-color: color-mix(in srgb, var(--ok) 70%, var(--line));
}

.feedback-panel.wrong {
  border-color: color-mix(in srgb, var(--danger) 70%, var(--line));
}

.feedback-panel h3 {
  margin: 0 0 8px;
}

.feedback-panel p {
  margin: 8px 0;
  color: var(--muted);
  line-height: 1.5;
}

.quiz-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 20px;
}

.result-summary {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  overflow: hidden;
  margin-bottom: 18px;
}

.result-summary div {
  display: grid;
  gap: 4px;
  padding: 18px;
  background: var(--panel);
}

.result-summary span {
  color: var(--muted);
  font-weight: 700;
}

.result-summary strong {
  font-size: 1.9rem;
}

.review-list {
  display: grid;
  gap: 14px;
}

.review-card {
  padding: 18px;
}

.review-card h3 {
  margin: 0 0 10px;
  font-size: 1.05rem;
}

.review-card p {
  margin: 7px 0;
  color: var(--muted);
  line-height: 1.5;
}

.review-card.correct {
  border-color: color-mix(in srgb, var(--ok) 70%, var(--line));
}

.review-card.wrong {
  border-color: color-mix(in srgb, var(--danger) 70%, var(--line));
}

.hidden {
  display: none !important;
}

@media (max-width: 900px) {
  .app-shell {
    grid-template-columns: 1fr;
  }

  .sidebar {
    position: static;
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  .question-nav {
    grid-template-columns: repeat(10, minmax(34px, 1fr));
  }

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

@media (max-width: 620px) {
  .main-panel,
  .sidebar {
    padding: 16px;
  }

  .topbar {
    display: grid;
  }

  .pill-row {
    justify-content: flex-start;
  }

  .topic-list,
  .result-summary {
    grid-template-columns: 1fr;
  }

  .question-nav {
    grid-template-columns: repeat(5, minmax(34px, 1fr));
  }
}