:root {
  --paper: #fffdf8;
  --ink: #242424;
  --muted: #68736d;
  --line: #d8dfd7;
  --accent: #0f8f83;
  --accent-strong: #096b63;
  --tomato: #da4b3f;
  --gold: #f2ba32;
  --green: #6aaa35;
  --pink: #e85b92;
  --blue: #4587a4;
  --purple: #7f4aa0;
  --black: #1d1d1d;
  --wrong: #b2322d;
  --correct: #207a44;
  --focus: #1b6f8f;
  --shadow: 0 10px 28px rgba(30, 30, 30, 0.09);
}

* {
  box-sizing: border-box;
}

html {
  min-height: 100%;
  background: #eef3ea;
}

body {
  min-height: 100%;
  margin: 0;
  color: var(--ink);
  font-family: ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.65), rgba(238, 243, 234, 0.8)),
    repeating-linear-gradient(90deg, rgba(15, 143, 131, 0.04) 0 1px, transparent 1px 46px);
}

button,
input {
  font: inherit;
}

button {
  -webkit-tap-highlight-color: transparent;
}

.app-shell {
  min-height: 100vh;
  display: grid;
  grid-template-rows: auto 1fr auto;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  display: grid;
  gap: 12px;
  padding: 14px clamp(14px, 3vw, 28px);
  background: rgba(255, 253, 248, 0.94);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(12px);
}

.topline {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.brand {
  display: grid;
  gap: 2px;
}

.brand h1 {
  margin: 0;
  font-size: clamp(1.2rem, 2.4vw, 2rem);
  letter-spacing: 0;
}

.brand span {
  color: var(--muted);
  font-size: 0.92rem;
}

.mode-pill {
  flex: 0 0 auto;
  padding: 8px 10px;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--accent-strong);
  background: #ffffff;
  font-weight: 700;
}

.progress-wrap {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 12px;
  align-items: center;
}

.progress {
  height: 10px;
  overflow: hidden;
  border-radius: 999px;
  background: #dde5dd;
}

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

.progress-label {
  color: var(--muted);
  font-size: 0.92rem;
  white-space: nowrap;
}

.main {
  width: min(1120px, 100%);
  margin: 0 auto;
  padding: clamp(16px, 3vw, 28px);
}

.page-head {
  display: grid;
  gap: 8px;
  margin-bottom: 18px;
}

.page-kicker {
  color: var(--accent-strong);
  font-weight: 800;
  text-transform: uppercase;
  font-size: 0.78rem;
  letter-spacing: 0.08em;
}

.page-title {
  margin: 0;
  font-size: clamp(1.55rem, 3.2vw, 2.4rem);
  letter-spacing: 0;
}

.page-instructions {
  max-width: 840px;
  margin: 0;
  color: #37433d;
  line-height: 1.45;
}

.test-panel,
.summary-panel {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--paper);
  box-shadow: var(--shadow);
}

.test-panel {
  padding: clamp(14px, 2.8vw, 24px);
}

.summary-panel {
  display: grid;
  gap: 14px;
  margin-bottom: 18px;
  padding: clamp(14px, 2.8vw, 22px);
}

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

.summary-stat {
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #ffffff;
}

.summary-stat b {
  display: block;
  font-size: clamp(1.35rem, 2.5vw, 2rem);
}

.summary-stat span {
  color: var(--muted);
  font-size: 0.9rem;
}

.question-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 12px;
}

.question-grid.wide {
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
}

.question {
  display: grid;
  gap: 10px;
  align-content: start;
  min-width: 0;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #ffffff;
}

.question.is-correct {
  border-color: rgba(32, 122, 68, 0.45);
  background: #f4fbf5;
}

.question.is-wrong {
  border-color: rgba(178, 50, 45, 0.45);
  background: #fff6f2;
}

.question-title {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  min-height: 28px;
  font-weight: 800;
}

.prompt-row {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  font-size: 1.15rem;
}

.answer-input {
  width: 100%;
  min-height: 48px;
  padding: 10px 12px;
  border: 2px solid #cdd8cf;
  border-radius: 8px;
  background: #ffffff;
  color: var(--ink);
}

.answer-input:focus {
  outline: 3px solid rgba(27, 111, 143, 0.22);
  border-color: var(--focus);
}

.answer-input:disabled {
  color: #515151;
  background: #f6f7f4;
}

.hint {
  color: var(--muted);
  font-size: 0.9rem;
}

.fraction {
  display: inline-grid;
  grid-template-rows: auto 2px auto;
  align-items: center;
  min-width: 1.6em;
  text-align: center;
  line-height: 1;
  font-weight: 800;
  vertical-align: middle;
}

.fraction .bar {
  display: block;
  width: 100%;
  height: 2px;
  background: currentColor;
}

.mixed {
  display: inline-flex;
  align-items: center;
  gap: 0.25em;
  font-weight: 800;
}

.operator {
  font-weight: 900;
  font-size: 1.45em;
}

.review-note {
  display: grid;
  gap: 6px;
  padding: 10px 12px;
  border-left: 4px solid var(--line);
  background: rgba(255, 255, 255, 0.72);
  color: #303732;
  line-height: 1.4;
}

.review-note.correct {
  border-left-color: var(--correct);
}

.review-note.wrong {
  border-left-color: var(--wrong);
}

.status-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 28px;
  height: 28px;
  padding: 0 8px;
  border-radius: 999px;
  color: #ffffff;
  font-size: 0.82rem;
}

.status-mark.correct {
  background: var(--correct);
}

.status-mark.wrong {
  background: var(--wrong);
}

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

.odd-row {
  display: grid;
  gap: 10px;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #ffffff;
}

.odd-options {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 10px;
}

.shape-option {
  position: relative;
  display: grid;
  place-items: center;
  min-height: 92px;
  padding: 12px;
  border: 0;
  background: #ffffff;
  color: var(--shape-color, var(--accent));
  cursor: pointer;
}

.shape-option:disabled,
.swatch:disabled,
.paint-tile:disabled,
.rank-chip:disabled {
  cursor: default;
}

.shape-option[data-selected="true"] {
  outline: 4px solid rgba(242, 186, 50, 0.45);
}

.shape-option:focus-visible {
  outline: 4px solid rgba(27, 111, 143, 0.25);
}

.shape-option::before,
.shape-option::after {
  content: "";
  position: absolute;
  z-index: 0;
  inset: 8px;
  background: currentColor;
}

.shape-option::after {
  inset: 11px;
  background: #ffffff;
}

.shape-option[data-selected="true"]::after {
  background: #fff8d8;
}

.shape-option.circle::before,
.shape-option.circle::after {
  border-radius: 999px;
}

.shape-option.hexagon::before,
.shape-option.hexagon::after {
  clip-path: polygon(25% 5%, 75% 5%, 100% 50%, 75% 95%, 25% 95%, 0 50%);
}

.shape-option.triangle::before,
.shape-option.triangle::after {
  clip-path: polygon(50% 0, 100% 92%, 0 92%);
}

.shape-option.triangle {
  min-height: 108px;
}

.shape-option span {
  position: relative;
  z-index: 1;
  color: var(--ink);
}

.addition-problem {
  display: grid;
  gap: 12px;
}

.grid-expression {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
}

.box-grid {
  display: grid;
  grid-template-columns: repeat(3, 24px);
  grid-template-rows: repeat(3, 24px);
  gap: 2px;
}

.mini-box {
  border: 1.5px solid #202020;
  border-radius: 5px;
  background: #ffffff;
}

.mini-box.filled {
  background: #fa3568;
}

.steer-note {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 12px;
  margin-bottom: 14px;
  color: var(--muted);
}

.steer-note span {
  display: inline-flex;
  align-items: center;
  min-height: 34px;
  padding: 6px 10px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: #ffffff;
}

.plants-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 16px;
}

.plant-group {
  display: grid;
  gap: 12px;
  padding: 14px;
  border: 2px solid var(--plant-line, var(--line));
  border-radius: 8px;
  background: #ffffff;
}

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

.swatch {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 40px;
  padding: 7px 10px;
  border: 2px solid #cfd8d0;
  border-radius: 999px;
  background: #ffffff;
  cursor: pointer;
}

.swatch::before {
  content: "";
  width: 18px;
  height: 18px;
  border: 1px solid rgba(0, 0, 0, 0.22);
  border-radius: 50%;
  background: var(--swatch-color);
}

.swatch[data-active="true"] {
  border-color: var(--focus);
  box-shadow: 0 0 0 3px rgba(27, 111, 143, 0.16);
}

.paint-grid {
  display: grid;
  grid-template-columns: repeat(var(--cols, 3), minmax(52px, 1fr));
  gap: 8px;
}

.paint-tile {
  position: relative;
  display: grid;
  place-items: center;
  aspect-ratio: 1;
  min-height: 58px;
  border: 2px solid #202020;
  border-radius: 6px;
  background: var(--tile-fill, #ffffff);
  color: #222222;
  cursor: pointer;
}

.paint-tile svg {
  width: 72%;
  height: 72%;
  fill: transparent;
  stroke: currentColor;
  stroke-width: 7;
  stroke-linecap: round;
  stroke-linejoin: round;
  pointer-events: none;
}

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

.rank-row {
  display: grid;
  gap: 12px;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #ffffff;
}

.rank-options,
.rank-answer {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
}

.rank-chip {
  min-width: 78px;
  min-height: 54px;
  display: inline-grid;
  place-items: center;
  padding: 8px 10px;
  border: 2px solid var(--blue);
  border-radius: 8px;
  background: #ffffff;
  cursor: pointer;
}

.rank-chip[data-used="true"] {
  opacity: 0.42;
}

.rank-slot {
  min-width: 78px;
  min-height: 54px;
  display: inline-grid;
  place-items: center;
  padding: 8px 10px;
  border: 2px dashed #bcc9c0;
  border-radius: 8px;
  background: #fbfcfa;
}

.secondary-action {
  width: fit-content;
  min-height: 40px;
  padding: 8px 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #ffffff;
  color: #2f3833;
  cursor: pointer;
}

.bottom-nav {
  position: sticky;
  bottom: 0;
  z-index: 9;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 12px clamp(14px, 3vw, 28px);
  border-top: 1px solid var(--line);
  background: rgba(255, 253, 248, 0.95);
  backdrop-filter: blur(12px);
}

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

.primary-btn,
.plain-btn,
.danger-btn {
  min-height: 46px;
  padding: 10px 14px;
  border-radius: 8px;
  border: 1px solid transparent;
  cursor: pointer;
  font-weight: 800;
}

.primary-btn {
  background: var(--accent);
  color: #ffffff;
}

.primary-btn:hover {
  background: var(--accent-strong);
}

.plain-btn {
  background: #ffffff;
  border-color: var(--line);
  color: #2f3833;
}

.danger-btn {
  background: #ffffff;
  border-color: rgba(178, 50, 45, 0.35);
  color: var(--wrong);
}

.primary-btn:disabled,
.plain-btn:disabled {
  cursor: not-allowed;
  opacity: 0.48;
}

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

.page-dot {
  min-width: 34px;
  height: 34px;
  padding: 0 8px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: #ffffff;
  color: #36403a;
  cursor: pointer;
}

.page-dot[data-active="true"] {
  color: #ffffff;
  background: var(--accent);
  border-color: var(--accent);
}

.page-dot[data-page-correct="true"] {
  border-color: rgba(32, 122, 68, 0.55);
}

.page-dot[data-page-wrong="true"] {
  border-color: rgba(178, 50, 45, 0.55);
}

.empty-answer {
  color: var(--muted);
  font-style: italic;
}

.screen-reader {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
}

@media (max-width: 760px) {
  .topline,
  .bottom-nav {
    align-items: stretch;
    flex-direction: column;
  }

  .progress-wrap {
    grid-template-columns: 1fr;
  }

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

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

  .shape-option {
    min-height: 82px;
  }

  .question-grid,
  .question-grid.wide,
  .plants-grid {
    grid-template-columns: 1fr;
  }

  .paint-grid {
    grid-template-columns: repeat(var(--cols, 3), minmax(44px, 1fr));
  }
}

@media (max-width: 440px) {
  .summary-grid {
    grid-template-columns: 1fr;
  }

  .nav-group,
  .primary-btn,
  .plain-btn,
  .danger-btn {
    width: 100%;
  }

  .primary-btn,
  .plain-btn,
  .danger-btn {
    justify-content: center;
  }
}