:root {
  --ink: #173026;
  --leaf: #145c38;
  --leaf-soft: #e7f6df;
  --sun: #f0c14a;
  --cream: #fffdf8;
  --line: #d5e6cc;
  --hint: #fff6e4;
  --hint-ink: #5c3b16;
  --shadow: 0 14px 36px rgba(40, 70, 40, 0.08);
  color: var(--ink);
  font-family: "Segoe UI", "Trebuchet MS", "Gill Sans", sans-serif;
  font-size: 1.2rem;
  line-height: 1.45;
  background:
    radial-gradient(900px 420px at 8% -10%, #fff1c2 0%, transparent 60%),
    radial-gradient(800px 480px at 110% 0%, #d9f5c6 0%, transparent 55%),
    linear-gradient(180deg, #f3fbe8 0%, #e7f4ea 42%, #f8f1e4 100%);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
}

button, input { font: inherit; color: inherit; }

button, .organ { touch-action: manipulation; }

button {
  min-height: 52px;
  border-radius: 999px;
  border: 3px solid var(--line);
  background: white;
  padding: 0.55rem 1.1rem;
  cursor: pointer;
}

button:hover { border-color: var(--leaf); }

.primary {
  background: var(--leaf);
  color: white;
  border-color: var(--leaf);
  font-weight: 700;
}

.primary:disabled {
  background: #9bb5a6;
  border-color: #9bb5a6;
  cursor: not-allowed;
}

.texty {
  background: none;
  border: none;
  color: var(--leaf);
  text-decoration: underline;
  padding-left: 0;
  padding-right: 0;
}

:focus-visible {
  outline: 4px solid var(--leaf);
  outline-offset: 3px;
}

.skip {
  position: absolute;
  left: 0.8rem;
  top: -4rem;
  background: white;
  padding: 0.6rem 1rem;
  z-index: 6;
}

.skip:focus { top: 0.8rem; }

.shell {
  max-width: 1120px;
  margin: 0 auto;
  padding: 1rem 1rem 2.5rem;
}

.topbar {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 0.55rem 1rem;
  align-items: center;
  margin-bottom: 0.8rem;
}

.mark {
  margin: 0;
  font-weight: 800;
  letter-spacing: 0.01em;
}

.mark::before {
  content: "";
  display: inline-block;
  width: 0.85rem;
  height: 0.85rem;
  margin-right: 0.45rem;
  border-radius: 50%;
  background: var(--sun);
  box-shadow: 0 0 0 6px rgba(240, 193, 74, 0.28);
}

.tools { display: flex; flex-wrap: wrap; gap: 0.45rem; justify-content: flex-end; }

.where {
  grid-column: 1 / -1;
  margin: 0;
  font-weight: 700;
}

.steps {
  grid-column: 1 / -1;
  list-style: none;
  display: flex;
  gap: 0.4rem;
  margin: 0;
  padding: 0 0 0.2rem;
  overflow-x: auto;
}

.steps li {
  padding: 0.35rem 0.75rem;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.75);
  white-space: nowrap;
}

.steps li.is-now { background: var(--leaf); color: white; }

.steps li.is-done { background: var(--leaf-soft); }

.layout {
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(280px, 0.85fr);
  gap: 1rem;
  align-items: start;
}

.layout-text { grid-template-columns: minmax(0, 46rem); }

.scene {
  background: radial-gradient(circle at 50% 42%, #ffffff 0%, rgba(255, 255, 255, 0.2) 68%);
  border-radius: 32px;
  padding: 0.4rem;
}

.card {
  background: rgba(255, 253, 248, 0.94);
  border-radius: 28px;
  padding: 1.15rem 1.2rem 1.3rem;
  box-shadow: var(--shadow);
}

.card-alone { max-width: 52rem; margin: 0 auto; }

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

h1 { font-size: clamp(1.7rem, 3vw, 2.6rem); line-height: 1.15; margin-bottom: 0.7rem; }

h2 { font-size: 1.45rem; margin-bottom: 0.35rem; }

.eyebrow, .progress, .help-line { color: #3d5a48; }

.lead { font-weight: 700; }

.choice {
  display: flex;
  width: 100%;
  justify-content: space-between;
  align-items: center;
  gap: 0.8rem;
  text-align: left;
  border-radius: 18px;
  margin: 0.55rem 0;
  padding: 0.85rem 1rem;
}

.choice small { color: var(--hint-ink); font-weight: 700; }

.choice.is-tried { background: var(--hint); border-style: dashed; }

.choice.is-right { border-color: var(--leaf); background: var(--leaf-soft); }

.feedback {
  border-radius: 16px;
  padding: 0.8rem 0.9rem;
}

.feedback.hint, .feedback.reveal { background: var(--hint); }

.feedback.correct, .feedback.neutral { background: var(--leaf-soft); }

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
  margin-top: 0.9rem;
}

.name-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  justify-content: center;
  padding: 0.2rem 0.4rem 0.7rem;
}

.name.met { background: var(--leaf-soft); }

.name.on { border-color: var(--leaf); font-weight: 800; }

.plant-cell { width: 100%; height: auto; display: block; }

.organ { cursor: pointer; }

.plant-cell[data-selected="wall"] .shape-wall,
.plant-cell:has(.organ[data-choice="wall"]:hover) .shape-wall,
.plant-cell:has(.organ[data-choice="wall"]:focus-visible) .shape-wall {
  filter: drop-shadow(0 0 7px rgba(176, 120, 60, 0.95));
}

.plant-cell[data-selected="membrane"] .shape-membrane,
.plant-cell:has(.organ[data-choice="membrane"]:hover) .shape-membrane,
.plant-cell:has(.organ[data-choice="membrane"]:focus-visible) .shape-membrane {
  stroke-width: 12;
  filter: drop-shadow(0 0 6px rgba(108, 76, 134, 0.95));
}

.plant-cell[data-selected="cytoplasm"] .shape-cytoplasm,
.plant-cell:has(.organ[data-choice="cytoplasm"]:hover) .shape-cytoplasm,
.plant-cell:has(.organ[data-choice="cytoplasm"]:focus-visible) .shape-cytoplasm {
  stroke: var(--leaf);
  stroke-width: 6;
}

.plant-cell[data-selected="vacuole"] .shape-vacuole,
.plant-cell:has(.organ[data-choice="vacuole"]:hover) .shape-vacuole,
.plant-cell:has(.organ[data-choice="vacuole"]:focus-visible) .shape-vacuole,
.plant-cell[data-selected="nucleus"] .shape-nucleus,
.plant-cell:has(.organ[data-choice="nucleus"]:hover) .shape-nucleus,
.plant-cell:has(.organ[data-choice="nucleus"]:focus-visible) .shape-nucleus,
.plant-cell[data-selected="chloroplast"] .shape-chloroplast,
.plant-cell:has(.organ[data-choice="chloroplast"]:hover) .shape-chloroplast,
.plant-cell:has(.organ[data-choice="chloroplast"]:focus-visible) .shape-chloroplast {
  filter: drop-shadow(0 0 8px rgba(20, 92, 56, 0.85));
}

.plant-cell.tried-wall .shape-wall,
.plant-cell.tried-membrane .shape-membrane,
.plant-cell.tried-cytoplasm .shape-cytoplasm,
.plant-cell.tried-vacuole .shape-vacuole,
.plant-cell.tried-nucleus .shape-nucleus,
.plant-cell.tried-chloroplast .shape-chloroplast {
  stroke: #8a5a32;
  stroke-dasharray: 10 8;
}

.fx, .marker { opacity: 0; }

.plant-cell[data-selected="wall"] .fx-wall,
.plant-cell[data-selected="membrane"] .fx-membrane,
.plant-cell[data-selected="nucleus"] .fx-nucleus,
.plant-cell[data-selected="vacuole"] .fx-vacuole,
.plant-cell[data-selected="cytoplasm"] .fx-cytoplasm,
.plant-cell[data-selected="chloroplast"] .fx-chloroplast {
  opacity: 1;
  animation: pulse 1.6s ease-in-out infinite;
}

.plant-cell[data-hint="outside"] .marker-outside,
.plant-cell[data-hint="rim"] .marker-rim,
.plant-cell[data-hint="center"] .marker-center,
.plant-cell[data-hint="side"] .marker-side,
.plant-cell[data-hint="jelly"] .marker-jelly,
.plant-cell[data-hint="ovals"] .marker-ovals {
  opacity: 1;
  animation: bob 1.1s ease-in-out infinite;
}

.pause-anim .fx, .pause-anim .marker { animation: none; }

.scope { padding: 0.4rem 0 0.8rem; }

.lens {
  width: min(86vw, 460px);
  aspect-ratio: 1;
  margin: 0 auto;
  border-radius: 50%;
  overflow: hidden;
  position: relative;
  background: #10210f;
  border: 16px solid #d08945;
  box-shadow: inset 0 0 48px rgba(0, 0, 0, 0.35), 0 16px 36px rgba(90, 50, 10, 0.16);
}

.tissue-wrap, .lens-cell { position: absolute; inset: 0; }

.tissue-wrap {
  filter: blur(var(--blur, 8px));
  transform: scale(var(--scale, 1));
  transform-origin: center center;
  transition: transform 0.2s linear, filter 0.2s linear, opacity 0.25s ease;
}

.lens-cell {
  opacity: 0;
  display: grid;
  place-items: center;
  background: #f4fbe9;
  padding: 7%;
  transition: opacity 0.25s ease;
}

.lens.is-revealed .tissue-wrap { opacity: 0; }

.lens.is-revealed .lens-cell { opacity: 1; }

.tissue-wrap svg, .lens-cell svg { width: 100%; height: 100%; }

.slider-block { margin: 0.8rem 0 0.4rem; }

.slider-ends, label {
  display: flex;
  justify-content: space-between;
  gap: 0.5rem;
  font-weight: 700;
}

input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 48px;
  background: transparent;
  margin: 0.2rem 0;
}

input[type="range"]::-webkit-slider-runnable-track {
  height: 14px;
  background: #d7edcf;
  border-radius: 999px;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 36px;
  height: 36px;
  margin-top: -11px;
  border-radius: 50%;
  background: var(--leaf);
  border: 3px solid white;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.2);
}

input[type="range"]::-moz-range-track {
  height: 14px;
  background: #d7edcf;
  border-radius: 999px;
  border: none;
}

input[type="range"]::-moz-range-thumb {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--leaf);
  border: 3px solid white;
}

.slides {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.8rem;
  margin-bottom: 0.8rem;
}

figure {
  margin: 0;
  background: white;
  border-radius: 20px;
  padding: 0.5rem 0.5rem 0.2rem;
  box-shadow: var(--shadow);
}

figcaption { font-weight: 800; text-align: center; padding-bottom: 0.4rem; }

figure svg { width: 100%; height: auto; display: block; }

.plain { padding-left: 1.1rem; }

.plain li { margin: 0.45rem 0; }

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

table {
  width: 100%;
  border-collapse: collapse;
  background: white;
  font-size: 1rem;
}

caption { text-align: left; font-weight: 700; margin-bottom: 0.4rem; }

th, td {
  text-align: left;
  vertical-align: top;
  padding: 0.55rem;
  border-bottom: 1px solid var(--line);
}

textarea {
  width: 100%;
  min-height: 12rem;
  margin-top: 0.8rem;
  border-radius: 16px;
  border: 3px solid var(--line);
  padding: 0.7rem;
  font: 0.95rem/1.4 ui-monospace, Consolas, monospace;
}

.scrim {
  position: fixed;
  inset: 0;
  background: rgba(23, 48, 38, 0.46);
  display: grid;
  place-items: center;
  z-index: 5;
  padding: 1rem;
}

.dialog {
  background: var(--cream);
  border-radius: 24px;
  max-width: 34rem;
  padding: 1.2rem;
  box-shadow: var(--shadow);
}

@keyframes pulse {
  0%, 100% { opacity: 0.45; }
  50% { opacity: 1; }
}

@keyframes bob {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-8px); }
}

@media (max-width: 860px) {
  .topbar { grid-template-columns: 1fr; }
  .tools { justify-content: flex-start; }
  .mark { white-space: nowrap; }
  .layout { grid-template-columns: 1fr; }
  .layout .scene { order: 2; }
  .layout .card { order: 1; }
  .slides { grid-template-columns: 1fr; }
}

@media (min-width: 900px) {
  :root { font-size: 1.28rem; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation: none !important;
    transition: none !important;
  }
}