/* ---------- Design tokens ---------- */
:root {
  --bg: #0b1020;
  --panel: #131a2e;
  --panel-2: #1b2440;
  --border: #2a3352;
  --text: #f4f6fb;
  --text-dim: #a7b0cc;
  --accent: #ffcc33;
  --accent-2: #4fd1c5;
  --accent-3: #ff6b6b;
  --accent-4: #7c9bff;
  --radius: 18px;
  --shadow: 0 10px 30px rgba(0,0,0,0.35);
  --space-1: 0.5rem;
  --space-2: 1rem;
  --space-3: 1.75rem;
  --space-4: 3rem;
}

* { box-sizing: border-box; }

html, body {
  height: 100%;
}

body {
  margin: 0;
  background: radial-gradient(circle at top, #171f38 0%, var(--bg) 60%);
  color: var(--text);
  font-family: -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  font-size: clamp(16px, 1.3vw, 22px);
  min-height: 100vh;
}

h1, h2, h3 { margin: 0; }

a { color: var(--accent-2); }

/* ---------- Buttons & controls ---------- */
.btn {
  font: inherit;
  font-weight: 700;
  color: var(--text);
  background: var(--panel-2);
  border: 2px solid var(--border);
  border-radius: 999px;
  padding: 0.7em 1.4em;
  cursor: pointer;
  transition: transform 0.08s ease, background 0.15s ease, border-color 0.15s ease;
  -webkit-tap-highlight-color: transparent;
}
.btn:hover { border-color: var(--accent-2); }
.btn:active { transform: scale(0.96); }
.btn:focus-visible { outline: 3px solid var(--accent-2); outline-offset: 2px; }

.btn-primary {
  background: linear-gradient(135deg, var(--accent-4), var(--accent-2));
  border-color: transparent;
  color: #04101f;
  font-size: 1.15em;
  padding: 0.75em 1.8em;
}

.btn-big {
  font-size: 1.4em;
  padding: 0.6em 1.6em;
  border-radius: var(--radius);
}

.btn-ghost {
  background: transparent;
  opacity: 0.75;
}
.btn-ghost:hover { opacity: 1; }

.btn-group {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  align-items: center;
  justify-content: center;
}

select, input[type="number"], input[type="range"] {
  font: inherit;
  color: var(--text);
  background: var(--panel-2);
  border: 2px solid var(--border);
  border-radius: 12px;
  padding: 0.5em 0.8em;
}

label.field {
  display: flex;
  flex-direction: column;
  gap: 0.3em;
  font-size: 0.85em;
  color: var(--text-dim);
  font-weight: 600;
}

.checkbox-field {
  display: flex;
  align-items: center;
  gap: 0.5em;
  font-size: 0.85em;
  color: var(--text-dim);
  font-weight: 600;
}
.checkbox-field input { width: 1.3em; height: 1.3em; }

/* ---------- Home page ---------- */
.home {
  max-width: 1100px;
  margin: 0 auto;
  padding: var(--space-4) var(--space-3) var(--space-4);
  text-align: center;
}

.home-title {
  font-size: clamp(2.2rem, 5vw, 3.5rem);
  letter-spacing: -0.02em;
}

.home-subtitle {
  color: var(--text-dim);
  max-width: 46em;
  margin: var(--space-2) auto var(--space-4);
  font-size: 1.1em;
}

.category-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: var(--space-3);
  text-align: left;
}

.card {
  display: block;
  background: var(--panel);
  border: 2px solid var(--border);
  border-radius: var(--radius);
  padding: var(--space-3);
  text-decoration: none;
  color: var(--text);
  box-shadow: var(--shadow);
  transition: transform 0.15s ease, border-color 0.15s ease;
}
.card:hover {
  transform: translateY(-4px);
  border-color: var(--accent-2);
}
.card .emoji {
  font-size: 2.6rem;
  display: block;
  margin-bottom: 0.4em;
}
.card h2 {
  font-size: 1.35rem;
  margin-bottom: 0.3em;
}
.card p {
  color: var(--text-dim);
  margin: 0;
  font-size: 0.95em;
  line-height: 1.4;
}

footer.site-footer {
  color: var(--text-dim);
  text-align: center;
  padding: var(--space-3);
  font-size: 0.85em;
}

/* ---------- Activity page shell ---------- */
.activity-page {
  height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-y: auto;
}

.top-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  border-bottom: 1px solid var(--border);
}

.top-bar .page-title {
  font-size: 1.3rem;
  text-align: center;
  flex: 1;
}

.home-link {
  color: var(--text-dim);
  text-decoration: none;
  font-weight: 700;
  white-space: nowrap;
}
.home-link:hover { color: var(--accent-2); }

.activity-main {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: var(--space-3);
  gap: var(--space-3);
  width: 100%;
}

.controls-bar {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  align-items: flex-end;
  justify-content: center;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: var(--space-2) var(--space-3);
  width: 100%;
  max-width: 1100px;
}

.stage {
  flex: 1;
  width: 100%;
  max-width: 1200px;
  min-height: 48vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: var(--space-3);
  position: relative;
  text-align: center;
}

.stage.blank {
  background: #05070f;
}

.big-number {
  font-size: clamp(3rem, 12vw, 9rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1;
}

.big-text {
  font-size: clamp(1.8rem, 6vw, 4.5rem);
  font-weight: 700;
  line-height: 1.2;
}

.faint {
  color: var(--text-dim);
  font-size: 0.6em;
  font-weight: 600;
}

.badge {
  display: inline-block;
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 0.3em 1em;
  font-size: 0.8em;
  color: var(--text-dim);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.progress-dots {
  display: flex;
  gap: 0.5em;
  justify-content: center;
}
.progress-dots span {
  width: 0.8em;
  height: 0.8em;
  border-radius: 50%;
  background: var(--border);
}
.progress-dots span.active {
  background: var(--accent);
}

.hint {
  color: var(--text-dim);
  font-size: 0.85em;
  text-align: center;
}

.curriculum-badge {
  text-align: center;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  color: var(--text-dim);
  padding: 0.4em;
  cursor: help;
}

.card-badge {
  display: inline-block;
  font-size: 0.7em;
  font-weight: 700;
  letter-spacing: 0.02em;
  text-transform: uppercase;
  color: var(--text-dim);
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 0.25em 0.8em;
  margin-top: 0.7em;
}

kbd {
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 0.1em 0.5em;
  font-family: inherit;
  font-size: 0.9em;
}

/* fullscreen tweaks: hide chrome, let stage breathe */
.activity-page:fullscreen .top-bar,
.activity-page:-webkit-full-screen .top-bar {
  opacity: 0.35;
}
.activity-page:fullscreen .top-bar:hover,
.activity-page:-webkit-full-screen .top-bar:hover {
  opacity: 1;
}
.activity-page:fullscreen,
.activity-page:-webkit-full-screen {
  background: var(--bg);
}

@media (max-width: 640px) {
  .top-bar { flex-wrap: wrap; }
  .top-bar .page-title { order: -1; flex-basis: 100%; }
}