:root {
  --bg: #0f1115;
  --panel: #171a21;
  --panel-2: #1e222b;
  --text: #e7eaf0;
  --muted: #8b93a5;
  --accent: #7c9cff;
  --good: #5fd39a;
  --bad: #ff7a7a;
  --border: #262b36;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--text);
  font: 15px/1.5 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

main {
  max-width: 760px;
  margin: 0 auto;
  padding: 32px 20px 60px;
}

[v-cloak] {
  visibility: hidden;
}

h1 {
  margin: 0;
  font-size: 26px;
  letter-spacing: -0.01em;
}

h2 {
  margin: 0 0 4px;
  font-size: 18px;
}

h3 {
  margin: 0 0 2px;
  font-size: 14px;
  color: var(--accent);
}

p {
  margin: 0;
}

.screen,
.brand,
.card,
.stack {
  display: flex;
  flex-direction: column;
}

.screen {
  gap: 16px;
}

.brand {
  gap: 2px;
}

.card {
  gap: 12px;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 18px;
}

.sub,
.muted {
  color: var(--muted);
}

.small {
  font-size: 13px;
}

.eyebrow {
  color: var(--muted);
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.error {
  color: var(--bad);
}

/* --- формы --- */

.field {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.field > span {
  color: var(--muted);
  font-size: 13px;
}

input,
select {
  width: 100%;
  background: var(--panel-2);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 10px;
  padding: 11px 14px;
  font: inherit;
}

input:focus,
select:focus {
  outline: none;
  border-color: var(--accent);
}

input[type="range"] {
  padding: 0;
  border: none;
  background: transparent;
  accent-color: var(--accent);
}

button {
  background: var(--accent);
  color: #0f1115;
  border: 1px solid transparent;
  border-radius: 10px;
  padding: 11px 18px;
  font: inherit;
  font-weight: 600;
  cursor: pointer;
  white-space: nowrap;
}

button:disabled {
  opacity: 0.45;
  cursor: default;
}

button.ghost {
  background: transparent;
  color: var(--muted);
  border-color: var(--border);
  font-weight: 500;
}

/* --- шапка тренировки --- */

.topbar {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
  justify-content: space-between;
}

.who {
  display: flex;
  flex-direction: column;
}

.who .muted {
  font-size: 13px;
}

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

.chip {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 5px 12px;
  font-size: 13px;
  color: var(--muted);
}

.chip.ok {
  color: var(--good);
  border-color: color-mix(in srgb, var(--good) 40%, var(--border));
}

.chip.fail {
  color: var(--bad);
  border-color: color-mix(in srgb, var(--bad) 40%, var(--border));
}

/* --- полоса задач --- */

.dots {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.dot {
  min-width: 34px;
  padding: 5px 8px;
  font-size: 13px;
  font-weight: 500;
  background: var(--panel);
  color: var(--muted);
  border: 1px solid var(--border);
}

.dot.ok {
  color: var(--good);
  border-color: color-mix(in srgb, var(--good) 45%, var(--border));
}

.dot.fail {
  color: var(--bad);
  border-color: color-mix(in srgb, var(--bad) 45%, var(--border));
}

.dot.hinted {
  border-style: dashed;
}

.dot.current {
  background: var(--accent);
  color: #0f1115;
  border-color: var(--accent);
}

/* --- задание и решение --- */

.task-card {
  align-items: center;
}

.expression {
  display: flex;
  align-items: baseline;
  justify-content: center;
  gap: 14px;
  font-size: 46px;
  font-weight: 600;
  letter-spacing: -0.02em;
  font-variant-numeric: tabular-nums;
}

.expression .op {
  color: var(--muted);
  font-weight: 400;
}

.expression .qmark {
  color: var(--accent);
}

.solve-row {
  display: flex;
  gap: 10px;
}

.answer {
  flex: 1;
  min-width: 0;
  font-size: 20px;
  font-weight: 600;
  text-align: center;
}

.verdict {
  font-weight: 600;
}

.verdict.ok {
  color: var(--good);
}

.verdict.fail {
  color: var(--bad);
}

/* --- кнопки перехода --- */

.nav {
  display: flex;
  gap: 10px;
}

.nav button {
  flex: 1;
}

/* Кнопки перехода в навигации — обычного цвета, «ghost» их делал похожими на выключенные. */
.nav button.ghost {
  color: var(--text);
}

.hint-btn {
  background: var(--panel-2);
  color: var(--accent);
  border-color: color-mix(in srgb, var(--accent) 45%, var(--border));
}

/* --- окно подсказок --- */

.overlay {
  position: fixed;
  inset: 0;
  background: rgb(6 8 12 / 70%);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  z-index: 10;
}

.modal {
  width: min(560px, 100%);
  max-height: 90vh;
  overflow: auto;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 18px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.modal-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.modal-head h2 {
  margin: 0;
  font-size: 16px;
}

.hints {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.hints > li {
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 12px 14px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.mini-table {
  list-style: none;
  margin: 4px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
  gap: 4px;
  font-variant-numeric: tabular-nums;
}

.mini-table li {
  padding: 3px 8px;
  border-radius: 7px;
  color: var(--muted);
  font-size: 14px;
}

.mini-table li.hit {
  background: color-mix(in srgb, var(--accent) 22%, transparent);
  color: var(--text);
}

.modal-foot {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 12px;
}

.reveal {
  font-size: 20px;
  font-weight: 600;
  font-variant-numeric: tabular-nums;
}

/* --- итоги --- */

.summary {
  align-items: center;
  text-align: center;
  gap: 4px;
}

.score {
  font-size: 40px;
  font-weight: 600;
  font-variant-numeric: tabular-nums;
}

.review {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.review li {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  background: var(--panel);
  border: 1px solid var(--border);
  border-left-width: 3px;
  border-radius: 10px;
  padding: 9px 14px;
}

.review li.ok {
  border-left-color: var(--good);
}

.review li.fail {
  border-left-color: var(--bad);
}

.review li.skipped {
  border-left-color: var(--border);
  color: var(--muted);
}

.review .expr {
  font-variant-numeric: tabular-nums;
  font-weight: 600;
}

.review .given {
  color: var(--muted);
  font-size: 13px;
}