:root {
  --bg: #12141b; --bg2: #1a1d27; --panel: #1f2330; --panel-hi: #292e3e; --line: #343a4d;
  --fg: #eceef4; --dim: #8e95a8; --accent: #4f8cff; --accent-hi: #7aa7ff; --good: #4fd18b; --warn: #ffd24a;
  --radius: 14px; --radius-sm: 10px; --gap: 12px; --gutter: 16px; --app-max: 560px;
  --fs-sm: clamp(11px, 2.5vmin, 15px); --fs: clamp(13px, 3vmin, 18px); --fs-big: clamp(20px, 5vmin, 32px);
  --shadow: 0 8px 28px rgba(0, 0, 0, .45); --dock-size: clamp(42px, 11vw, 70px); --dock-gap: 8px; --danger: #e0443e; --paper: #f3e3c4;
}
* { box-sizing: border-box; -webkit-tap-highlight-color: transparent; }
html, body { margin: 0; height: 100%; background: radial-gradient(120% 90% at 50% 0%, var(--bg2), var(--bg)); color: var(--fg);
  font-family: system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif; font-size: var(--fs); overscroll-behavior: none; user-select: none; }
button { font: inherit; color: inherit; border: 0; cursor: pointer; }
button:focus-visible, .switch input:focus-visible + i { outline: 2px solid var(--accent-hi); outline-offset: 2px; }

/* ---- game screen ---- */
#app { height: 100%; max-width: var(--app-max); margin: 0 auto; display: flex; flex-direction: column;
  padding: max(8px, env(safe-area-inset-top)) var(--gutter) max(8px, env(safe-area-inset-bottom)); gap: 6px; }
header { display: grid; grid-template-columns: 1fr auto 1fr; align-items: center; gap: var(--gap); }
header small, .best small { display: block; color: var(--dim); font-size: var(--fs-sm); text-transform: uppercase; letter-spacing: .06em; }
header b, .best b { font-size: var(--fs-big); line-height: 1.1; font-variant-numeric: tabular-nums; }
.score { text-align: center; }
.score b { font-size: calc(var(--fs-big) * 1.5); }
.chain { justify-self: start; padding-left: var(--gap); min-width: 4em; }
.icon-btn { justify-self: start; width: 2.6em; height: 2.6em; border-radius: var(--radius-sm); background: var(--panel); border: 1px solid var(--line); font-size: 1.1em; }
.icon-btn:active { background: var(--panel-hi); }

#goal { position: relative; height: 1.7em; background: var(--panel); border: 1px solid var(--line); border-radius: 99px; overflow: hidden; display: grid; place-items: center; }
#fill { position: absolute; inset: 0 auto 0 0; width: 0; background: linear-gradient(90deg, var(--accent), var(--accent-hi)); border-radius: 99px; transition: width .35s; }
#goalTxt { position: relative; font-size: var(--fs-sm); font-weight: 600; font-variant-numeric: tabular-nums; text-shadow: 0 1px 2px rgba(0, 0, 0, .6); }

#wrap { position: relative; }
#hint { position: absolute; left: 50%; bottom: 10px; transform: translateX(-50%); max-width: 92%; background: var(--panel); border: 1px solid var(--accent);
  border-radius: 99px; padding: .45em 1em; font-size: var(--fs-sm); text-align: center; pointer-events: none; box-shadow: var(--shadow); }

#bottom { display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: var(--gap); }
.best { justify-self: start; }
.best.end { justify-self: end; text-align: right; }
#dock { display: flex; justify-content: center; gap: var(--dock-gap); padding-top: 2px; }
#dock[hidden] { display: none; }
.dock-btn { position: relative; width: var(--dock-size); height: var(--dock-size); border-radius: var(--radius); background: var(--panel);
  border: 1px solid var(--line); padding: 10px; display: grid; place-items: center; transition: transform .1s, background .15s; }
.dock-btn svg { width: 100%; height: 100%; }
.dock-btn:active:not(:disabled) { transform: scale(.94); }
.dock-btn.on { background: var(--accent); border-color: var(--accent-hi); }
.dock-btn:disabled { opacity: .35; cursor: default; }
.count { --count-scale: .5; position: absolute; top: calc(-7px * var(--count-scale)); right: calc(-7px * var(--count-scale));
  font-size: max(9px, calc(var(--fs-big) * var(--count-scale))); min-width: 1.6em; padding: .1em .35em; border-radius: 99px; background: var(--fg); color: var(--bg);
  text-align: center; line-height: 1.4; font-weight: 700; }
.dock-btn:disabled .count { background: var(--dim); }

#wrap { flex: 1; min-height: 0; background: linear-gradient(180deg, rgba(0,0,0,.18), rgba(0,0,0,.32)); border-radius: var(--radius); border: 1px solid var(--line); }
canvas { width: 100%; height: 100%; display: block; touch-action: none; }

#toast { position: fixed; left: 50%; top: max(10px, env(safe-area-inset-top)); transform: translate(-50%, -8px); background: var(--panel); border: 2px solid var(--accent);
  border-radius: var(--radius); padding: .6em 1.1em; font-size: var(--fs); text-align: center; box-shadow: var(--shadow);
  opacity: 0; pointer-events: none; transition: opacity .3s, transform .3s; z-index: 5; max-width: 90vw; }
#toast.show { opacity: 1; transform: translate(-50%, 0); }

/* ---- overlay screens (menu, how to play, game over) ---- */
.screen { position: fixed; inset: 0; z-index: 4; display: none; align-items: flex-start; justify-content: center; overflow-y: auto;
  background: rgba(10, 11, 16, .86); backdrop-filter: blur(6px); padding: max(16px, env(safe-area-inset-top)) var(--gutter) max(16px, env(safe-area-inset-bottom)); }
.screen.show { display: flex; }
.card { width: 100%; max-width: 460px; margin: auto; background: var(--panel); border: 1px solid var(--line); border-radius: calc(var(--radius) * 1.4);
  padding: calc(var(--gutter) * 1.4); box-shadow: var(--shadow); display: flex; flex-direction: column; gap: var(--gap); }
.card h1 { margin: 0; font-size: calc(var(--fs-big) * 1.5); text-align: center; letter-spacing: -.02em;
  background: linear-gradient(90deg, var(--accent-hi), var(--good)); -webkit-background-clip: text; background-clip: text; color: transparent; }
.card h2 { margin: 0; font-size: var(--fs-big); text-align: center; }
.card h3 { margin: .4em 0 0; font-size: var(--fs-sm); color: var(--dim); text-transform: uppercase; letter-spacing: .08em; }
.tag { margin: 0; text-align: center; color: var(--dim); }
.chips { display: flex; justify-content: center; gap: 8px; padding: 4px 0; }
.chip { min-width: 2.4em; padding: .55em .4em; border-radius: var(--radius-sm); text-align: center; font-weight: 700; box-shadow: 0 3px 0 rgba(0,0,0,.35); }

.btn { display: block; width: 100%; padding: .85em 1em; border-radius: var(--radius-sm); background: var(--panel-hi); border: 1px solid var(--line); font-weight: 600; text-align: center; }
.btn:active { filter: brightness(1.15); }
.btn.primary { background: linear-gradient(180deg, var(--accent-hi), var(--accent)); border-color: var(--accent-hi); font-size: 1.15em; }
.row { display: flex; gap: 8px; }
.row > * { flex: 1; }

.seg { display: flex; background: var(--bg); border-radius: var(--radius-sm); padding: 4px; gap: 4px; }
.seg button { flex: 1; padding: .6em 0; border-radius: calc(var(--radius-sm) - 3px); background: transparent; color: var(--dim); font-weight: 600; }
.seg button.on { background: var(--accent); color: #fff; }
#blurb { margin: 0; color: var(--dim); font-size: var(--fs-sm); min-height: 2.6em; }

.rule { display: flex; align-items: center; gap: var(--gap); padding: .5em 0; border-top: 1px solid var(--line); cursor: pointer; }
.rule:first-of-type { border-top: 0; }
.rule span { flex: 1; }
.rule small { display: block; color: var(--dim); font-size: var(--fs-sm); }
.switch { position: relative; width: 2.8em; height: 1.6em; flex: none; }
.switch input { position: absolute; opacity: 0; inset: 0; margin: 0; cursor: pointer; }
.switch i { position: absolute; inset: 0; background: var(--bg); border: 1px solid var(--line); border-radius: 99px; transition: background .2s; }
.switch i::after { content: ''; position: absolute; top: 2px; left: 2px; width: calc(1.6em - 6px); height: calc(1.6em - 6px); background: var(--dim); border-radius: 50%; transition: transform .2s, background .2s; }
.switch input:checked + i { background: color-mix(in srgb, var(--accent) 55%, var(--bg)); border-color: var(--accent); }
.switch input:checked + i::after { transform: translateX(1.2em); background: #fff; }
#note { margin: 0; color: var(--warn); font-size: var(--fs-sm); text-align: center; min-height: 1.2em; }

.how { margin: 0; padding-left: 1.2em; display: flex; flex-direction: column; gap: .6em; }
.how li::marker { color: var(--accent-hi); }
.how b { color: var(--fg); }
.big { text-align: center; font-size: calc(var(--fs-big) * 1.8); font-weight: 800; font-variant-numeric: tabular-nums; line-height: 1; }
.badge { align-self: center; background: var(--warn); color: #222; border-radius: 99px; padding: .2em .8em; font-weight: 700; font-size: var(--fs-sm); }
[hidden] { display: none !important; }