:root {
  --ink: #f5f5f0;
  --muted: #b8b4aa;
  --line: #4a4842;
  --paper: #302e2c;
  --panel: #262522;
  --panel-strong: #3c3a35;
  --board: #f0d9b5;
  --board-dark: #b58863;
  --green: #81b64c;
  --green-dark: #5f8f2f;
  --green-hover: #95c85a;
  --green-soft: #2f3f24;
  --brown: #b58863;
  --brown-soft: #40382f;
  --red: #e07070;
  --red-soft: #4a2d2d;
  --blue: #81b64c;
  font-family: "Segoe UI", system-ui, sans-serif;
}

* {
  box-sizing: border-box;
}

.hidden {
  display: none !important;
}

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

button,
input,
select {
  font: inherit;
}

button {
  min-height: 42px;
  border: 1px solid var(--green-dark);
  border-radius: 7px;
  background: var(--green);
  color: #ffffff;
  cursor: pointer;
  font-weight: 700;
  padding: 0 14px;
}

button:hover:not(:disabled) {
  background: var(--green-hover);
  border-color: var(--green-hover);
}

button:active {
  transform: translateY(1px);
}

button:disabled {
  cursor: not-allowed;
  opacity: 0.55;
}

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

h1 {
  font-size: clamp(28px, 5vw, 48px);
  line-height: 1.05;
}

h2 {
  font-size: 22px;
  line-height: 1.15;
}

.app-shell {
  min-height: 100vh;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 3;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  border-bottom: 1px solid var(--line);
  background: rgba(38, 37, 34, 0.95);
  padding: 12px 18px;
  backdrop-filter: blur(10px);
}

.auth-status {
  display: flex;
  align-items: center;
  gap: 8px;
}

body:not([data-view="home"]) .auth-status {
  display: none;
}

body[data-view="home"] .topnav {
  display: none;
}

#userLabel {
  color: var(--muted);
  font-size: 13px;
  max-width: 220px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.brand-button {
  min-height: 40px;
  border: 0;
  background: transparent;
  font-size: 24px;
  font-weight: 800;
  padding: 0;
}

.brand-button:hover:not(:disabled) {
  background: transparent;
  color: var(--green-hover);
}

.topnav {
  display: flex;
  gap: 8px;
}

.topnav button.active,
.set-tabs button.active,
#sandboxBtn.active {
  border-color: var(--blue);
  background: var(--green-soft);
  color: var(--green-dark);
  font-weight: 700;
}

.view {
  width: min(1180px, 100%);
  margin: 0 auto;
  padding: 28px 18px;
}

.view.hidden {
  display: none;
}

.home-view,
.auth-view,
.setup-view {
  display: grid;
  align-content: center;
  min-height: calc(100vh - 65px);
}

.home-header,
.section-heading,
.setup-panel {
  max-width: 780px;
}

.auth-panel {
  width: min(560px, 100%);
  margin: 0 auto;
}

.auth-controls {
  display: grid;
  gap: 12px;
  margin-top: 22px;
}

.meta,
.turn-label,
.session-progress {
  color: var(--muted);
  font-size: 14px;
}

.home-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
  margin-top: 28px;
}

.mode-card {
  display: grid;
  align-content: start;
  min-height: 150px;
  text-align: left;
  background: linear-gradient(180deg, var(--green) 0%, var(--green-dark) 100%);
  border-color: var(--green-dark);
  color: #ffffff;
  padding: 20px;
}

.mode-card strong {
  display: block;
  font-size: 24px;
}

.mode-card span {
  display: block;
  margin-top: 12px;
  color: rgba(255, 255, 255, 0.84);
  line-height: 1.4;
}

.set-summary {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
  margin-top: 24px;
}

.home-progress-panel {
  display: grid;
  gap: 10px;
  margin-top: 18px;
}

.home-progress-heading {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 12px;
}

.home-progress {
  width: 100%;
  height: auto;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
}

.contact-panel {
  display: grid;
  gap: 12px;
  margin-top: 18px;
}

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

.contact-card {
  display: grid;
  gap: 7px;
  min-height: 84px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  color: var(--ink);
  padding: 14px;
  text-decoration: none;
}

.contact-card span {
  color: var(--muted);
  font-size: 12px;
  font-weight: 800;
  text-transform: uppercase;
}

.contact-card strong {
  overflow-wrap: anywhere;
  font-size: 18px;
}

.contact-card:hover {
  border-color: var(--green-dark);
  background: var(--green-soft);
}

.copy-card {
  cursor: text;
  user-select: all;
}

.copy-card:hover {
  border-color: var(--line);
  background: var(--panel);
}

.set-summary-item,
.stat {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  padding: 12px;
}

.set-summary-item strong,
.stat strong,
.stat span {
  display: block;
}

.set-summary-item {
  display: grid;
  gap: 10px;
}

.metric-row,
.set-info {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.metric-chip {
  display: inline-grid;
  min-width: 82px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel-strong);
  color: var(--ink);
  padding: 8px 10px;
}

.metric-chip strong {
  font-size: 20px;
  line-height: 1;
}

.metric-chip small {
  margin-top: 4px;
  color: var(--muted);
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
}

.metric-chip.due {
  border-color: #79a940;
  background: var(--green-soft);
}

.metric-chip.new {
  border-color: var(--brown);
  background: var(--brown-soft);
}

.metric-chip.total {
  background: var(--panel-strong);
}

.set-summary-item span,
.stat span {
  color: var(--muted);
  font-size: 12px;
}

.setup-panel {
  width: min(560px, 100%);
  margin: 0 auto;
}

.session-controls {
  display: grid;
  gap: 12px;
  margin-top: 22px;
}

.session-controls label {
  display: grid;
  gap: 6px;
  color: var(--muted);
  font-size: 13px;
}

.session-controls input,
.session-controls select,
.stats-search {
  width: 100%;
  min-height: 42px;
  border: 1px solid var(--line);
  border-radius: 7px;
  background: var(--panel-strong);
  color: var(--ink);
  padding: 0 10px;
}

.primary-action {
  border-color: var(--green-dark);
  background: var(--green);
  color: #ffffff;
  font-weight: 700;
}

.session-view {
  display: grid;
  grid-template-rows: auto minmax(260px, 1fr) auto;
  gap: 14px;
  min-height: calc(100vh - 65px);
}

body[data-view="session"] .topnav,
body[data-view="session"] .auth-status {
  display: none;
}

body[data-view="session"] .topbar {
  justify-content: flex-start;
  min-height: 52px;
  padding: 8px 16px;
}

body[data-view="session"] .brand-button {
  min-height: 36px;
  font-size: 20px;
}

body[data-view="session"] .session-view {
  width: min(900px, 100%);
  min-height: calc(100vh - 52px);
  grid-template-rows: auto minmax(0, 1fr) auto;
  gap: 6px;
  padding: 6px 12px 8px;
  justify-items: center;
}

.study-header,
.move-panel,
.header-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

.study-header,
.move-panel {
  justify-content: space-between;
}

body[data-view="session"] .study-header {
  display: grid;
  gap: 6px;
  justify-content: center;
  justify-items: center;
  width: min(100%, 680px);
}

body[data-view="session"] .study-header > div:first-child {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  width: 100%;
}

body[data-view="session"] #problemMeta,
body[data-view="session"] #problemTitle,
body[data-view="session"] #statusPill {
  display: none;
}

body[data-view="session"] .session-progress,
body[data-view="session"] .turn-heading {
  display: inline-flex;
  align-items: center;
  min-height: 34px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel-strong);
  color: var(--ink);
  font-size: 14px;
  font-weight: 800;
  padding: 0 12px;
}

body[data-view="session"] .turn-heading {
  margin-top: 0;
}

body[data-view="session"] .header-actions {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 8px;
  justify-self: center;
  margin-inline: auto;
  width: min(100%, 280px);
}

body[data-view="session"] .header-actions button {
  min-height: 38px;
}

.study-header h1 {
  margin-top: 4px;
  font-size: clamp(24px, 4vw, 38px);
}

.status-pill {
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  margin-top: 8px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--panel-strong);
  color: var(--muted);
  font-size: 13px;
  font-weight: 700;
  padding: 0 10px;
}

.status-pill.good {
  border-color: var(--green-dark);
  background: var(--green-soft);
  color: var(--green);
}

.status-pill.bad {
  border-color: var(--red);
  background: var(--red-soft);
  color: var(--red);
}

.status-pill.hint,
.status-pill.sandbox,
.status-pill.done {
  border-color: var(--brown);
  background: var(--brown-soft);
  color: #7a583b;
}

.review-forecast {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 8px;
}

.forecast-pill {
  display: inline-flex;
  align-items: center;
  min-height: 34px;
  border: 1px solid var(--line);
  border-radius: 7px;
  font-size: 13px;
  font-weight: 800;
  padding: 0 11px;
}

.forecast-pill.wrong {
  border-color: var(--red);
  background: var(--red-soft);
  color: #8f2d2d;
}

.forecast-pill.correct {
  border-color: var(--green-dark);
  background: var(--green-soft);
  color: var(--green-dark);
}

.turn-heading {
  margin-top: 8px;
  font-size: 20px;
  font-weight: 800;
}

.board-stage {
  display: grid;
  place-items: center;
  min-height: 0;
}

body[data-view="session"] .board-stage {
  width: 100%;
  justify-items: center;
  min-height: 0;
}

#board {
  display: block;
  width: min(100%, calc(100vh - 230px));
  max-width: 760px;
  aspect-ratio: 1;
  height: auto;
  border: 1px solid var(--board-dark);
  border-radius: 8px;
  background: var(--board);
  box-shadow: 0 18px 48px rgba(54, 34, 8, 0.18);
  touch-action: manipulation;
}

body[data-view="session"] #board {
  width: min(100%, calc(100vh - 286px));
  max-width: min(680px, 100%);
}

.feedback {
  margin-top: 5px;
  max-width: 68ch;
  line-height: 1.35;
}

body[data-view="session"] .move-panel {
  display: grid;
  grid-template-columns: 1fr;
  justify-items: center;
  gap: 8px;
  width: min(100%, 760px);
}

body[data-view="session"] .move-panel > div {
  display: grid;
  justify-items: center;
  gap: 6px;
  width: 100%;
}

body[data-view="session"] .turn-label {
  display: none;
}

body[data-view="session"] .review-forecast {
  justify-content: center;
  margin-top: 0;
}

body[data-view="session"] .feedback {
  min-height: 20px;
  margin-top: 0;
  font-size: 13px;
  text-align: center;
}

body[data-view="session"] #nextBtn {
  width: min(100%, 220px);
  min-height: 48px;
  font-size: 18px;
}

.feedback.good {
  color: var(--green);
}

.feedback.bad {
  color: var(--red);
}

.feedback.hint,
.feedback.sandbox {
  color: #d9bc8c;
}

.feedback.done {
  color: var(--green-dark);
  font-weight: 700;
}

.stats-view,
.browse-view {
  display: grid;
  gap: 18px;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 10px;
}

.stats-panel {
  display: grid;
  gap: 12px;
}

.browser-layout {
  display: grid;
  grid-template-columns: minmax(250px, 360px) minmax(0, 1fr);
  gap: 16px;
  align-items: start;
}

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

.problem-list,
.stats-problem-list {
  display: grid;
  gap: 7px;
  max-height: 55vh;
  overflow: auto;
}

.problem-list {
  margin-top: 10px;
}

.problem-item,
.stats-problem-item {
  width: 100%;
  min-height: 48px;
  text-align: left;
  background: transparent;
}

.problem-item.active,
.stats-problem-item.active {
  border-color: var(--blue);
  background: var(--green-soft);
}

.problem-title {
  display: block;
  font-weight: 700;
}

.problem-due {
  display: block;
  color: var(--muted);
  font-size: 13px;
  margin-top: 3px;
}

.import-btn {
  width: 100%;
  margin-top: 12px;
}

.selected-problem-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px;
}

.trend {
  width: 100%;
  height: auto;
  margin-top: 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
}

.history-list {
  display: grid;
  gap: 7px;
  margin-top: 10px;
}

.history-item {
  border-bottom: 1px solid var(--line);
  padding-bottom: 7px;
  font-size: 13px;
  line-height: 1.35;
}

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

.history-item span {
  color: var(--muted);
}

@media (max-width: 860px) {
  .topbar {
    min-height: 54px;
    padding: 8px 12px;
  }

  .topnav,
  .auth-status {
    display: none;
  }

  .home-grid,
  .set-summary,
  .contact-grid,
  .stats-grid,
  .browser-layout,
  .selected-problem-stats {
    grid-template-columns: 1fr;
  }

  .home-progress-heading {
    align-items: start;
    flex-direction: column;
  }

  .home-view,
  .auth-view,
  .setup-view,
  .session-view {
    min-height: calc(100vh - 54px);
  }

  .home-view {
    display: flex;
    flex-direction: column;
    gap: 14px;
  }

  .home-grid {
    display: contents;
  }

  .home-header {
    order: 1;
  }

  #homeTrainingBtn {
    order: 2;
  }

  .home-progress-panel {
    order: 3;
    margin-top: 0;
  }

  #homeStatsBtn {
    order: 4;
  }

  #homeBrowseBtn {
    order: 5;
  }

  .set-summary {
    order: 6;
    margin-top: 0;
  }

  .contact-panel {
    order: 7;
    margin-top: 0;
  }

  body[data-view="session"] .session-view {
    width: 100%;
    min-height: calc(100dvh - 54px);
    grid-template-rows: 1fr;
    gap: 0;
    padding: 0 8px 126px;
  }

  body[data-view="session"] .study-header {
    display: block;
  }

  body[data-view="session"] .study-header > div:first-child {
    display: none;
  }

  body[data-view="session"] .header-actions {
    position: fixed;
    right: 8px;
    bottom: 68px;
    left: 8px;
    z-index: 5;
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 8px;
  }

  body[data-view="session"] .header-actions button {
    min-height: 46px;
    padding: 0 8px;
  }

  body[data-view="session"] .board-stage {
    min-height: calc(100dvh - 180px);
    padding: 6px 0 10px;
  }

  body[data-view="session"] .move-panel {
    position: fixed;
    right: 8px;
    bottom: 8px;
    left: 8px;
    z-index: 5;
    display: block;
  }

  body[data-view="session"] .move-panel > div {
    display: grid;
    gap: 6px;
  }

  body[data-view="session"] #nextBtn {
    width: 100%;
    min-height: 52px;
    font-size: 18px;
  }

  body[data-view="session"] .turn-label {
    display: none;
  }

  body[data-view="session"] .feedback {
    display: block;
    min-height: 0;
    font-size: 12px;
  }

  body[data-view="session"] .review-forecast {
    justify-content: center;
  }

  body[data-view="session"] #board {
    width: min(100%, 94vw, calc(100dvh - 216px));
    max-width: none;
  }
}