* {
  box-sizing: border-box;
}

:root {
  color-scheme: light;
  --ink: #121826;
  --navy: #17206a;
  --muted: #5d6675;
  --paper: #ffffff;
  --canvas: #fbfaf7;
  --wash: #f6f2ea;
  --line: #e1ded6;
  --line-strong: #c5c0b5;
  --blue: #2d5fa8;
  --blue-dark: #214783;
  --green: #0f766e;
  --green-soft: #dff5ed;
  --gold: #b68020;
  --gold-soft: #fff2c7;
  --red: #b2343f;
  --violet: #6b55b6;
  --teal: #087b86;
  --cell: 52px;
  --shadow: 0 18px 50px rgba(18, 24, 38, 0.07);
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: Inter, "Helvetica Neue", Arial, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: var(--canvas);
  color: var(--ink);
  font-feature-settings: "tnum";
}

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

button {
  min-height: 42px;
  border: 1px solid transparent;
  border-radius: 7px;
  cursor: pointer;
  font-weight: 700;
  letter-spacing: 0.01em;
}

button:disabled {
  cursor: not-allowed;
  opacity: 0.42;
}

.site-nav {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  justify-content: space-between;
  gap: 18px;
  align-items: center;
  padding: 18px max(22px, calc((100vw - 1180px) / 2 + 22px));
  border-bottom: 1px solid var(--line);
  background: rgba(251, 250, 247, 0.92);
  backdrop-filter: blur(14px);
}

.site-nav a {
  color: var(--navy);
  text-decoration: none;
  font-size: 0.84rem;
  font-weight: 650;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.site-nav a:hover {
  text-decoration: underline;
  text-underline-offset: 4px;
}

.site-nav div {
  display: flex;
  gap: 22px;
  align-items: center;
}

.site-nav .brand-link {
  color: var(--ink);
  font-size: 0.95rem;
  font-weight: 750;
  letter-spacing: 0;
  text-transform: none;
}

body.study-active .site-nav .brand-link {
  pointer-events: none;
  cursor: default;
  text-decoration: none;
}

.formal-admin-test-link {
  display: none;
}

body.formal-mode .site-nav div,
body.formal-mode .designer-panel,
body.formal-mode #refreshListBtn,
body.formal-mode #exportBtn,
body.formal-mode #downloadBtn,
body.formal-mode #restartBtn {
  display: none;
}

body.tester-mode .site-nav div {
  display: flex;
}

body.formal-mode .formal-admin-test-link {
  display: none;
  align-items: center;
  color: rgba(93, 102, 117, 0.68);
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

body.formal-mode .formal-admin-test-link:hover {
  color: var(--navy);
}

body.tester-mode .formal-admin-test-link {
  display: none;
}

body.study-active .formal-admin-test-link {
  display: none;
}

.shell {
  width: min(1180px, 100%);
  margin: 0 auto;
  padding: 30px 18px 56px;
}

.panel {
  border: 1px solid var(--line);
  background: var(--paper);
  box-shadow: 0 12px 32px rgba(18, 24, 38, 0.04);
  padding: 26px;
  border-radius: 8px;
}

.hidden {
  display: none;
}

.setup-panel {
  box-shadow: var(--shadow);
}

.setup-layout {
  display: grid;
  grid-template-columns: minmax(0, 0.88fr) minmax(430px, 1.12fr);
  gap: 28px;
  align-items: start;
}

.setup-primary {
  display: grid;
  gap: 14px;
  padding: 8px 0;
}

.eyebrow {
  margin: 0 0 16px;
  color: var(--navy);
  font-size: 0.74rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

h1,
h2,
p {
  margin-top: 0;
}

h1 {
  max-width: 600px;
  margin-bottom: 6px;
  color: var(--navy);
  font-size: clamp(1.55rem, 3vw, 2.35rem);
  font-weight: 760;
  letter-spacing: 0;
  line-height: 1.08;
  text-wrap: balance;
}

h2 {
  margin-bottom: 9px;
  color: var(--ink);
  font-size: 1.02rem;
  font-weight: 750;
}

.intro {
  max-width: 590px;
  margin-bottom: 0;
  color: var(--muted);
  line-height: 1.65;
}

.setup-grid,
.designer-grid {
  display: grid;
  gap: 12px;
}

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

.formal-info {
  display: grid;
  gap: 10px;
  padding: 16px;
  border: 1px solid var(--line);
  border-left: 4px solid var(--navy);
  background: #fffefa;
  border-radius: 8px;
}

.formal-info p {
  margin: 0;
  color: var(--muted);
  line-height: 1.55;
}

.tester-login {
  display: grid;
  gap: 12px;
  padding: 16px;
  border: 1px solid #ead7a4;
  border-left: 4px solid var(--gold);
  background: #fffaf0;
  border-radius: 8px;
}

.tester-login p {
  margin: 4px 0 0;
  line-height: 1.45;
}

.tester-login.hidden {
  display: none;
}

.consent-check {
  display: flex;
  gap: 9px;
  align-items: flex-start;
  line-height: 1.4;
}

.consent-check input {
  width: auto;
  margin-top: 2px;
}

.designer-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
  margin-bottom: 12px;
}

label {
  display: block;
  color: var(--ink);
  font-size: 0.9rem;
  font-weight: 700;
}

input,
select,
textarea {
  width: 100%;
  margin-top: 7px;
  padding: 11px 12px;
  border: 1px solid var(--line-strong);
  border-radius: 6px;
  background: #fff;
  color: var(--ink);
}

input:focus,
select:focus,
textarea:focus,
button:focus-visible {
  outline: 3px solid rgba(23, 32, 106, 0.18);
  outline-offset: 2px;
}

input:invalid {
  border-color: var(--red);
}

input[readonly] {
  background: #f4f1e9;
  color: var(--muted);
}

.designer-panel,
.overview-panel,
.prompt-card,
.answer-card,
.trial-sidebar,
.visual-area {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--paper);
}

.designer-panel {
  padding: 0 14px 14px;
}

.designer-panel summary {
  padding: 14px 0;
  cursor: pointer;
  color: var(--navy);
  font-weight: 750;
}

.hidden-control {
  display: none;
}

.overview-panel {
  padding: 18px;
  background: #fffefa;
  border-radius: 8px;
}

.overview-header {
  display: flex;
  justify-content: space-between;
  gap: 14px;
  align-items: flex-start;
}

.overview-header h2 {
  margin-bottom: 4px;
}

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

.count-row,
.type-picker,
.setup-actions,
.actions,
.number-pad,
.operator-pad,
.edit-pad,
.maze-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
}

.count-row {
  margin: 18px 0;
}

.count-chip {
  padding: 7px 10px;
  border: 1px solid var(--line);
  background: #ffffff;
  color: #435061;
  font-size: 0.86rem;
  font-weight: 700;
  border-radius: 999px;
}

.type-picker {
  margin: 0;
  padding: 12px;
  border: 1px solid var(--line);
  background: #fffefa;
  border-radius: 8px;
}

.type-picker legend {
  padding: 0 8px;
  color: var(--muted);
  font-weight: 700;
}

.type-picker label {
  display: inline-flex;
  gap: 7px;
  min-height: 34px;
  align-items: center;
  padding: 7px 10px;
  border: 1px solid var(--line);
  background: #ffffff;
  border-radius: 999px;
}

.type-picker input {
  width: auto;
  margin: 0;
}

.setup-actions,
.actions {
  margin-top: 4px;
}

.primary,
.secondary {
  padding: 10px 18px;
  transition: background 140ms ease, color 140ms ease, border-color 140ms ease, transform 140ms ease;
}

.primary {
  background: var(--navy);
  color: #fff;
}

.primary:hover:not(:disabled) {
  background: #0f174f;
  transform: translateY(-1px);
}

.secondary {
  border-color: var(--navy);
  background: transparent;
  color: var(--navy);
}

.secondary:hover:not(:disabled) {
  background: var(--blue-soft, #eef1fb);
  transform: translateY(-1px);
}

.trial-panel {
  display: grid;
  gap: 16px;
}

.trial-panel.hidden {
  display: none;
}

.study-progress {
  display: grid;
  gap: 8px;
}

.progress-copy,
.topbar,
.answer-topline {
  display: flex;
  justify-content: space-between;
  gap: 14px;
  align-items: center;
}

progress {
  width: 100%;
  height: 10px;
  overflow: hidden;
  border: 0;
  border-radius: 999px;
  background: #e4e1d8;
}

progress::-webkit-progress-bar {
  background: #e4e1d8;
  border-radius: 999px;
}

progress::-webkit-progress-value {
  background: var(--navy);
  border-radius: 999px;
}

progress::-moz-progress-bar {
  background: var(--navy);
  border-radius: 999px;
}

.progress-breakdown {
  font-size: 0.9rem;
}

.completion-code {
  margin: 14px 0;
  padding: 14px;
  border: 1px solid var(--navy);
  background: #fffefa;
  color: var(--navy);
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-weight: 800;
}

.trial-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 294px;
  gap: 18px;
  align-items: start;
}

.trial-main {
  display: grid;
  gap: 14px;
  min-width: 0;
}

.trial-sidebar {
  position: sticky;
  top: 76px;
  max-height: calc(100vh - 92px);
  overflow: hidden;
  padding: 14px;
}

.trial-sidebar h2 {
  margin-bottom: 4px;
}

#metaText {
  display: block;
  color: var(--muted);
  margin-top: 4px;
}

.prompt-card,
.answer-card {
  padding: 15px;
  border-radius: 8px;
}

.prompt-card p {
  margin-bottom: 0;
  color: #2d3849;
  line-height: 1.5;
  white-space: pre-line;
}

.visual-area {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 320px;
  padding: 20px;
  background: var(--wash);
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.55);
}

.puzzle-list {
  display: grid;
  gap: 6px;
  overflow: auto;
  padding-right: 4px;
}

.setup-list {
  max-height: 560px;
  grid-template-columns: repeat(auto-fill, minmax(198px, 1fr));
}

.trial-list {
  max-height: calc(100vh - 206px);
}

.puzzle-list-item {
  display: grid;
  grid-template-columns: 38px minmax(74px, 1fr) 34px;
  align-items: center;
  gap: 7px;
  min-height: 34px;
  padding: 6px 7px;
  border: 1px solid var(--line);
  background: #ffffff;
  border-radius: 6px;
}

.puzzle-list-item.current {
  border-color: var(--navy);
  box-shadow: inset 3px 0 0 var(--navy);
}

.puzzle-list-item.answered {
  border-color: #93c7b5;
  background: #ecf8f2;
}

.puzzle-list-item.skipped {
  border-color: #dfbf7f;
  background: #fff8e7;
}

.puzzle-list-item.pending {
  color: var(--muted);
}

.list-number {
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 800;
}

.list-id {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.8rem;
  font-weight: 760;
  white-space: nowrap;
}

.list-type {
  display: inline-grid;
  min-width: 30px;
  min-height: 22px;
  place-items: center;
  border-radius: 999px;
  color: #fff;
  font-size: 0.72rem;
  font-weight: 850;
}

.list-type.arithmetic24 { background: var(--blue); }
.list-type.maze { background: var(--green); }
.list-type.grid_placement { background: var(--violet); }
.list-type.minesweeper_lite { background: var(--red); }
.list-type.mini_sudoku { background: var(--teal); }

.answer-preview {
  min-height: 48px;
  margin: 10px 0 12px;
  padding: 12px;
  overflow-x: auto;
  white-space: pre-wrap;
  border: 1px solid var(--line);
  background: #fffefa;
  color: var(--ink);
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  border-radius: 6px;
}

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

.status {
  min-height: 22px;
  margin: 10px 0 0;
  color: var(--muted);
  font-weight: 700;
}

.status.ok { color: var(--green); }
.status.warn { color: var(--gold); }

.number-pad,
.operator-pad,
.edit-pad,
.maze-controls {
  justify-content: center;
}

.number-chip {
  min-width: 74px;
  min-height: 66px;
  padding: 12px 16px;
  border-color: #b8c7e4;
  background: #f1f6ff;
  color: #193b72;
  font-size: 1.55rem;
}

.operator-button,
.move-button {
  width: 48px;
  height: 48px;
  border-color: var(--line-strong);
  background: #ffffff;
  color: var(--ink);
  font-size: 1.3rem;
}

.operator-button:hover,
.move-button:hover {
  border-color: var(--blue);
}

.maze-grid,
.placement-grid,
.single-cell-grid {
  display: grid;
  gap: 5px;
  width: fit-content;
  max-width: 100%;
}

.sudoku-grid {
  gap: 0;
  border: 3px solid #182238;
  border-radius: 7px;
  overflow: hidden;
  background: #182238;
  box-shadow: 0 10px 26px rgba(18, 24, 38, 0.08);
}

.grid-cell {
  width: var(--cell);
  height: var(--cell);
  display: grid;
  place-items: center;
  border: 1px solid #aeb8b1;
  border-radius: 6px;
  background: #ffffff;
  color: var(--ink);
  font-size: 1.05rem;
}

.maze-cell.wall,
.placement-cell.blocked {
  border-color: #293447;
  background: #293447;
  color: #fff;
}

.maze-cell.wall:disabled,
.placement-cell.blocked:disabled,
.mine-cell.clue:disabled,
.sudoku-cell.fixed:disabled {
  opacity: 1;
}

.maze-cell.start {
  border-color: #0d6c55;
  background: #dff5e8;
  color: #064e3b;
  font-weight: 900;
}

.maze-cell.goal {
  border-color: #a22c32;
  background: #fde7e5;
  color: #7f1d1d;
  font-weight: 900;
}

.maze-cell.path {
  border-color: var(--gold);
  background: #f5d77b;
  color: #563a09;
  font-weight: 900;
}

.maze-cell.current,
.chosen-cell {
  outline: 3px solid rgba(23, 32, 106, 0.34);
  outline-offset: 2px;
}

.move-pad {
  display: grid;
  grid-template-columns: repeat(3, 48px);
  grid-template-areas:
    ". up ."
    "left . right"
    ". down .";
  gap: 7px;
}

.move-pad button:nth-child(1) { grid-area: up; }
.move-pad button:nth-child(2) { grid-area: left; }
.move-pad button:nth-child(3) { grid-area: right; }
.move-pad button:nth-child(4) { grid-area: down; }

.placement-wrap {
  display: grid;
  gap: 12px;
  justify-items: center;
}

.placement-cell.blocked { font-weight: 900; }

.placement-cell.token {
  border-color: #0f766e;
  background: #ccfbf1;
  color: #134e4a;
  font-size: 1.35rem;
  font-weight: 900;
}

.placement-cell.line-used {
  background: #eef3f1;
  color: var(--muted);
}

.mine-cell.clue,
.sudoku-cell.fixed {
  border-color: var(--line-strong);
  background: #e8eeec;
  color: var(--ink);
  font-weight: 900;
}

.mine-cell.known-mine {
  background: #293447;
  border-color: #293447;
  color: #fff;
}

.mine-cell.zero-clue {
  color: #8a94a3;
  background: #f4f6f5;
}

.mine-cell:not(.clue) {
  background: #fff2e4;
  color: #9a3412;
  font-weight: 900;
}

.sudoku-cell {
  border-radius: 0;
  border-color: #c9d1cf;
  font-size: 1.12rem;
}

.sudoku-cell:not(.fixed) {
  background: #fffdf8;
}

.sudoku-cell.fixed {
  background: #e6ecec;
}

.sudoku-cell.sudoku-box-odd:not(.fixed) {
  background: #f7fbfa;
}

.sudoku-cell.sudoku-box-odd.fixed {
  background: #dde7e6;
}

.sudoku-cell.box-top {
  border-top-width: 3px;
  border-top-color: #182238;
}

.sudoku-cell.box-bottom {
  border-bottom-width: 3px;
  border-bottom-color: #182238;
}

.sudoku-cell.box-left {
  border-left-width: 3px;
  border-left-color: #182238;
}

.sudoku-cell.box-right {
  border-right-width: 3px;
  border-right-color: #182238;
}

.chosen-cell {
  border-color: var(--navy);
  background: #dce8ff !important;
  color: #1f3c73 !important;
  font-size: 1.28rem;
  font-weight: 900;
}

.cue-cell:not(.chosen-cell) {
  border-color: var(--gold);
  outline: 3px solid var(--gold);
  outline-offset: -4px;
  box-shadow: none;
}

.cue-note {
  color: var(--muted);
  font-size: 0.88rem;
  font-weight: 700;
}

.placement-legend {
  color: var(--muted);
  font-weight: 800;
}

.done-panel textarea {
  min-height: 260px;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

.break-panel {
  display: grid;
  justify-items: start;
  gap: 12px;
  max-width: 620px;
  margin: 80px auto 0;
  padding: 34px;
}

.break-panel.hidden {
  display: none;
}

.break-panel p {
  max-width: 520px;
  margin-bottom: 0;
  color: var(--muted);
  line-height: 1.65;
}

@media (max-width: 980px) {
  .setup-layout,
  .trial-layout {
    grid-template-columns: 1fr;
  }

  .trial-sidebar {
    position: static;
    max-height: none;
  }

  .trial-list {
    max-height: 220px;
  }
}

@media (max-width: 720px) {
  .site-nav,
  .topbar,
  .answer-topline,
  .overview-header,
  .progress-copy {
    align-items: flex-start;
    flex-direction: column;
  }

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

  h1 {
    font-size: 1.75rem;
  }

  .panel {
    padding: 18px;
  }

  .formal-info p {
    font-size: 0.98rem;
  }

  .visual-area {
    justify-content: flex-start;
    overflow-x: auto;
  }

  .grid-cell {
    width: 42px;
    height: 42px;
  }
}