:root {
  --paper: #f8f7f2;
  --ink: #202124;
  --muted: #686b72;
  --line: #d9d5c8;
  --blue: #2269a8;
  --green: #2f7d62;
  --red: #a94035;
  --gold: #d6a642;
  --panel: #ffffff;
  --shadow: 0 10px 30px rgba(34, 38, 42, .08);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.45;
}

button,
input,
textarea,
select {
  font: inherit;
}

button {
  border: 0;
  cursor: pointer;
}

.app {
  min-height: 100svh;
}

.shell {
  width: min(1180px, 100%);
  margin: 0 auto;
  padding: 16px;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(248, 247, 242, .94);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(12px);
}

.topbar-inner {
  width: min(1180px, 100%);
  margin: 0 auto;
  padding: 12px 16px;
  display: flex;
  gap: 12px;
  align-items: center;
  justify-content: space-between;
}

.brand {
  min-width: 0;
  overflow: hidden;
}

.brand h1 {
  margin: 0;
  font-size: 1.05rem;
  letter-spacing: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.brand p {
  margin: 2px 0 0;
  color: var(--muted);
  font-size: .86rem;
}

.userbar {
  display: flex;
  align-items: center;
  gap: 8px;
  white-space: nowrap;
  min-width: 0;
}

.account-pill {
  max-width: 9.5rem;
  overflow: hidden;
  text-overflow: ellipsis;
}

.pill {
  display: inline-flex;
  align-items: center;
  min-height: 34px;
  padding: 6px 10px;
  border-radius: 999px;
  background: #ebe7dc;
  color: #3b3a35;
  font-size: .86rem;
}

.button {
  min-height: 42px;
  padding: 10px 14px;
  border-radius: 8px;
  background: var(--blue);
  color: #fff;
  font-weight: 700;
}

.button.secondary {
  background: #e8e5dc;
  color: var(--ink);
}

.button.ghost {
  background: transparent;
  color: var(--blue);
  padding-inline: 8px;
}

.button:disabled {
  opacity: .5;
  cursor: default;
}

.auth-screen {
  min-height: 100svh;
  display: grid;
  place-items: center;
  padding: 18px;
}

.auth-card {
  width: min(440px, 100%);
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 22px;
  box-shadow: var(--shadow);
}

.auth-card h1 {
  margin: 0 0 8px;
  font-size: clamp(1.6rem, 8vw, 2.35rem);
  line-height: 1.05;
  letter-spacing: 0;
}

.auth-card p {
  margin: 0 0 18px;
  color: var(--muted);
}

.field {
  display: grid;
  gap: 6px;
  margin: 12px 0;
}

.field span {
  font-size: .86rem;
  color: var(--muted);
  font-weight: 700;
}

.field input,
.field textarea {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  color: var(--ink);
  padding: 11px 12px;
  min-height: 44px;
}

.field textarea {
  min-height: 160px;
  resize: vertical;
}

.auth-actions,
.row-actions {
  display: flex;
  gap: 8px;
  align-items: center;
  flex-wrap: wrap;
}

.notice {
  min-height: 24px;
  margin: 10px 0 0;
  color: var(--red);
  font-weight: 700;
}

.layout {
  display: grid;
  gap: 16px;
}

.dashboard {
  display: grid;
  gap: 12px;
}

.progress-band {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 14px;
}

.meter {
  overflow: hidden;
  height: 12px;
  border-radius: 999px;
  background: #e2ded2;
}

.meter span {
  display: block;
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, var(--green), var(--gold));
}

.lesson-list {
  display: grid;
  gap: 10px;
}

.lesson-button {
  display: grid;
  gap: 4px;
  width: 100%;
  text-align: left;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 14px;
  color: var(--ink);
}

.lesson-button.active {
  border-color: var(--blue);
  outline: 2px solid rgba(34, 105, 168, .15);
}

.lesson-button strong {
  font-size: 1rem;
}

.lesson-button span {
  color: var(--muted);
  font-size: .88rem;
}

.lesson-work {
  display: grid;
  gap: 14px;
}

.lesson-head {
  display: grid;
  gap: 6px;
}

.lesson-head h2 {
  margin: 0;
  font-size: 1.5rem;
  letter-spacing: 0;
}

.lesson-head p {
  margin: 0;
  color: var(--muted);
}

.activity-grid {
  display: grid;
  gap: 10px;
  order: 3;
}

.activity-button {
  width: 100%;
  min-height: 58px;
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: 10px;
  text-align: left;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  color: var(--ink);
  padding: 12px;
}

.activity-button.active {
  border-color: var(--blue);
  background: #f2f7fb;
}

.activity-button.done .status-dot {
  background: var(--green);
}

.status-dot {
  width: 12px;
  height: 12px;
  border-radius: 99px;
  background: #c8c2b4;
}

.activity {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 16px;
  box-shadow: var(--shadow);
  order: 2;
  scroll-margin-top: 112px;
}

.lesson-head {
  order: 1;
}

.activity-nav {
  position: sticky;
  top: 92px;
  z-index: 4;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 8px;
  margin: 12px 0;
  padding: 8px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255, 255, 255, .94);
}

.activity-nav span {
  color: var(--muted);
  font-weight: 800;
}

.activity h3 {
  margin: 0 0 4px;
  font-size: 1.3rem;
  letter-spacing: 0;
}

.source {
  color: var(--muted);
  font-size: .84rem;
  margin-bottom: 14px;
}

.block,
.question,
.card,
.match-row,
.sort-item {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
}

.block {
  padding: 12px;
  margin: 10px 0;
}

.block h4 {
  margin: 0 0 8px;
  font-size: 1rem;
}

.block ul {
  margin: 0;
  padding-left: 18px;
}

.table-wrap {
  overflow-x: auto;
}

table {
  width: 100%;
  border-collapse: collapse;
  min-width: 430px;
}

td,
th {
  border: 1px solid var(--line);
  padding: 8px;
  text-align: left;
  vertical-align: top;
}

.cards {
  display: grid;
  gap: 10px;
}

.card {
  min-height: 88px;
  padding: 13px;
  display: grid;
  align-content: center;
  gap: 8px;
}

.card button {
  width: 100%;
  text-align: left;
  background: transparent;
  color: inherit;
}

.cz {
  font-weight: 800;
  font-size: 1.08rem;
}

.en {
  color: var(--muted);
}

.question {
  padding: 12px;
  margin: 10px 0;
}

.option-grid {
  display: grid;
  gap: 8px;
  margin-top: 10px;
}

.option {
  min-height: 42px;
  border-radius: 8px;
  background: #ece8de;
  color: var(--ink);
  padding: 9px 10px;
  text-align: left;
}

.option.selected {
  background: #dbeaf6;
  outline: 2px solid var(--blue);
}

.option.correct {
  background: #dff0e8;
}

.option.wrong {
  background: #f3ddd9;
}

.match-board,
.sort-board {
  display: grid;
  gap: 10px;
}

.match-row {
  display: grid;
  gap: 8px;
  padding: 10px;
}

.match-row select {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 8px;
  min-height: 42px;
  background: #fff;
  color: var(--ink);
  padding: 8px;
}

.sort-item {
  display: grid;
  gap: 8px;
  padding: 10px;
}

.sort-item select {
  border: 1px solid var(--line);
  border-radius: 8px;
  min-height: 42px;
  background: #fff;
}

.fill-line {
  margin: 8px 0;
}

.fill-select {
  display: inline-block;
  min-width: min(270px, 100%);
  margin: 2px 3px;
  border: 1px solid var(--line);
  border-radius: 8px;
  min-height: 38px;
  padding: 6px 8px;
  background: #fff;
}

.score {
  margin: 12px 0 0;
  font-weight: 800;
  color: var(--blue);
}

.result-text {
  margin-top: 6px;
  font-size: .88rem;
  font-weight: 800;
}

.checklist {
  display: grid;
  gap: 6px;
  margin: 12px 0;
}

.checklist label {
  display: flex;
  gap: 8px;
  align-items: start;
}

.footer-space {
  height: 24px;
}

@media (min-width: 860px) {
  .shell {
    padding: 22px;
  }

  .layout {
    grid-template-columns: 320px 1fr;
    align-items: start;
  }

  .dashboard {
    position: sticky;
    top: 76px;
  }

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

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