:root {
  --ink: #2a2118;
  --ink-soft: #6d5e4f;
  --paper: #f4eee4;
  --paper-2: #fffdf8;
  --line: #e4d5c2;
  --tomato: #c23b22;
  --tomato-deep: #8e2414;
  --gold: #d4a017;
  --gold-soft: #f3dd9a;
  --ok: #1f7a45;
  --bad: #9f1d14;
  --radius: 18px;
  --font: "PingFang TC", "Noto Sans TC", "Microsoft JhengHei", sans-serif;
  --safe-top: env(safe-area-inset-top, 0px);
  --safe-bottom: env(safe-area-inset-bottom, 0px);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  min-height: 100dvh;
  font-family: var(--font);
  color: var(--ink);
  background:
    radial-gradient(900px 420px at 8% -10%, rgba(194, 59, 34, 0.12), transparent 52%),
    linear-gradient(180deg, #fbf6ee 0%, var(--paper) 48%, #efe4d4 100%);
  line-height: 1.6;
}

button, select, input { font: inherit; }

.skip-link {
  position: absolute;
  left: 1rem;
  top: -3rem;
  background: var(--ink);
  color: #fff;
  padding: 0.4rem 0.7rem;
  z-index: 20;
}

.skip-link:focus { top: 0.6rem; }

.site-header {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  align-items: center;
  padding: calc(0.7rem + var(--safe-top)) 1rem 0.7rem;
  background: rgba(255, 253, 248, 0.94);
  border-bottom: 1px solid var(--line);
  position: sticky;
  top: 0;
  z-index: 5;
}

.brand {
  display: flex;
  gap: 0.7rem;
  align-items: center;
  color: inherit;
  text-decoration: none;
  min-width: 0;
}

.brand img { width: 40px; height: 40px; border-radius: 12px; }
.brand strong { display: block; font-size: 0.98rem; }

.mode-tabs { display: flex; gap: 0.4rem; flex-shrink: 0; }

.mode-tab {
  border: 1px solid var(--line);
  background: transparent;
  border-radius: 999px;
  padding: 0.45rem 0.9rem;
  cursor: pointer;
}

.mode-tab[aria-selected="true"] {
  background: var(--tomato);
  color: #fff8ee;
  border-color: var(--tomato);
}

.banner, .hero, #learn-root { width: min(1080px, calc(100% - 2rem)); margin-inline: auto; }
.banner {
  margin-top: 1rem;
  background: #fff8ee;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 0.8rem 1rem;
  font-size: 1.05rem;
}

.hero h1 { font-size: clamp(2rem, 4vw, 3rem); margin: 0.8rem 0 0.2rem; }
.lead { margin: 0; color: var(--ink-soft); font-size: 1.15rem; }

.cards, .example-grid { display: grid; gap: 0.8rem; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }
.card, .example, .panel, .cheat {
  background: var(--paper-2);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1rem 1.1rem;
  margin-top: 0.9rem;
}
.card h2, .panel h2 { margin: 0 0 0.4rem; font-size: 1.25rem; }
.card p, .example p { margin: 0; }

.cheat summary { cursor: pointer; font-weight: 700; font-size: 1.1rem; }
.table-wrap { overflow-x: auto; }
.cheat-table { width: 100%; border-collapse: collapse; margin-top: 0.8rem; }
.cheat-table th, .cheat-table td { border-bottom: 1px solid var(--line); text-align: left; padding: 0.55rem; vertical-align: top; }
.cheat-table th { background: #f8efe2; }

.prompt, .hud-prompt { font-size: clamp(2rem, 5vw, 3.2rem); font-weight: 800; letter-spacing: 0.03em; margin: 0.2rem 0; }
.hint, .wb-label { color: var(--ink-soft); }
.digit-row { display: flex; flex-wrap: wrap; gap: 0.45rem; }
.digit-btn, .btn, .pad {
  border: 0;
  border-radius: 12px;
  background: var(--tomato);
  color: #fff8ee;
  min-width: 2.8rem;
  min-height: 2.8rem;
  font-size: 1.35rem;
  font-weight: 800;
  cursor: pointer;
}
.btn { padding: 0.65rem 1.1rem; font-size: 1.05rem; }
.btn-ghost { background: transparent; color: var(--ink); border: 1px solid var(--line); }
.digit-btn.is-ok { background: var(--ok); }
.digit-btn.is-bad { background: var(--bad); }
.digit-btn:disabled { cursor: default; }
.wb-actions { display: flex; flex-wrap: wrap; gap: 0.5rem; margin-top: 0.8rem; }
.feedback-line { min-height: 3.2rem; font-size: 1.2rem; font-weight: 700; }

.site-footer { width: 100%; padding: 1.5rem 1rem 2rem; color: var(--ink-soft); text-align: center; }
.site-footer p { margin: 0; text-align: center; }
.site-footer a { color: var(--tomato-deep); }

#view-game { scroll-margin-top: 4.75rem; }

.game-shell {
  position: relative;
  height: calc(100dvh - 8.5rem);
  min-height: 520px;
  margin: 0.8rem;
  border-radius: 20px;
  overflow: hidden;
  background: #17141c;
}

#game-canvas { width: 100%; height: 100%; display: block; cursor: none; }

#crosshair {
  position: absolute;
  left: 50%;
  top: 50%;
  width: 22px;
  height: 22px;
  transform: translate(-50%, -50%);
  pointer-events: none;
  border: 2px solid #fff8ee;
  border-radius: 50%;
  box-shadow: 0 0 0 2px rgba(0, 0, 0, 0.45);
}

#crosshair::before, #crosshair::after {
  content: "";
  position: absolute;
  background: #fff8ee;
}

#crosshair::before { left: 50%; top: -8px; width: 2px; height: 38px; transform: translateX(-50%); }
#crosshair::after { top: 50%; left: -8px; height: 2px; width: 38px; transform: translateY(-50%); }

.hud {
  position: absolute;
  inset: 0;
  pointer-events: none;
  color: #fff8ee;
  text-shadow: 0 2px 0 rgba(0, 0, 0, 0.35);
}

.hud-top, .hud-stats, .boss-wrap, .hud-kicker, .hud-prompt {
  pointer-events: none;
}

.hud-top {
  display: flex;
  justify-content: space-between;
  gap: 0.6rem;
  align-items: center;
  padding: 0.7rem 0.8rem;
}

.hud-top p { margin: 0; font-size: 1.15rem; font-weight: 800; }
.hud-top .btn { pointer-events: auto; background: rgba(255, 248, 238, 0.92); }

.hud-kicker {
  text-align: center;
  margin: 0;
  font-size: 1.05rem;
  letter-spacing: 0.12em;
}

.hud-prompt { text-align: center; }

.hud-stats {
  display: flex;
  justify-content: center;
  gap: 1.2rem;
  margin: 0;
  font-size: 1.25rem;
}

.hud-stats p { margin: 0; background: rgba(20, 14, 12, 0.72); padding: 0.25rem 0.7rem; border-radius: 999px; }
.boss-wrap { width: min(420px, 80%); margin: 0.6rem auto 0; text-align: center; }
.boss-track { height: 16px; background: rgba(255,255,255,0.25); border-radius: 999px; overflow: hidden; }
#boss-fill { height: 100%; width: 100%; background: #e15a45; }
#boss-label { margin: 0.25rem 0 0; font-weight: 800; }

.score-pop {
  position: absolute;
  left: 50%;
  top: 42%;
  transform: translate(-50%, 8px);
  opacity: 0;
  font-size: 2rem;
  font-weight: 800;
  color: var(--gold-soft);
}

.score-pop.is-on { animation: pop 0.7s ease; }

@keyframes pop {
  0% { opacity: 0; transform: translate(-50%, 10px); }
  20% { opacity: 1; transform: translate(-50%, 0); }
  100% { opacity: 0; transform: translate(-50%, -24px); }
}

.move-pad {
  position: absolute;
  left: 0;
  right: 0;
  bottom: calc(0.6rem + var(--safe-bottom));
  display: none;
  justify-content: space-between;
  padding: 0 0.6rem;
  pointer-events: none;
}

.pad { pointer-events: auto; min-width: 5.5rem; background: rgba(255, 248, 238, 0.9); color: var(--ink); }

@media (pointer: coarse) {
  .move-pad { display: flex; }
}

.overlay {
  position: absolute;
  inset: auto 4% 8% 4%;
  background: rgba(255, 253, 248, 0.96);
  color: var(--ink);
  border-radius: 20px;
  padding: 1rem 1.1rem 1.1rem;
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.28);
  max-height: 78%;
  overflow: auto;
}

.overlay h2 { margin: 0 0 0.3rem; font-size: 1.8rem; }
.help { margin: 0.6rem 0; padding-left: 1.2rem; }
.help li { margin: 0.25rem 0; }
.settings { display: grid; gap: 0.55rem; margin: 0.8rem 0; }
.settings label { display: grid; gap: 0.2rem; font-weight: 700; }
.settings select, .settings input[type="range"] { width: 100%; }
.check { display: flex !important; align-items: center; gap: 0.4rem; }
.overlay-feedback { inset: auto 6% 18% 6%; text-align: center; }
#feedback-text { margin: 0; font-size: clamp(1.35rem, 3vw, 2rem); font-weight: 800; line-height: 1.45; }
#feedback-text.is-ok { color: var(--ok); }
#feedback-text.is-bad { color: var(--bad); }
#summary-body, #final-stats { font-size: 1.25rem; font-weight: 700; }

@media (max-width: 720px) {
  .site-header { flex-wrap: wrap; }
  .game-shell { height: calc(100dvh - 11rem); margin: 0.4rem; }
}