:root{color-scheme:light;--accent:#5539de;--bg:#f8fafc;--ink:#1e293b;--muted:#64748b}*{box-sizing:border-box}body{margin:0;min-height:100vh;font-family:Inter,ui-rounded,system-ui,sans-serif;color:var(--ink);background:radial-gradient(circle at 15% 0%,color-mix(in srgb,var(--accent) 6%,transparent),transparent 34%),var(--bg)}.shell{width:100%;min-height:100dvh;padding:max(16px,env(safe-area-inset-top)) max(16px,env(safe-area-inset-right)) max(16px,env(safe-area-inset-bottom)) max(16px,env(safe-area-inset-left))}header{display:flex;align-items:start;justify-content:space-between;gap:20px;flex-wrap:wrap}.eyebrow{text-transform:uppercase;letter-spacing:.15em;color:var(--accent);font-weight:800;font-size:.72rem;margin:0 0 8px}h1{font-size:clamp(1.6rem,6vw,2.8rem);line-height:.95;letter-spacing:-.03em;margin:0;max-width:760px;color:#0f172a}.pitch{color:var(--muted);font-size:1.05rem;max-width:620px}.stats{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;margin:25px 0 14px}.stats div{background:#f8fafc;border:1px solid #e2e8f0;border-radius:16px;padding:12px 16px;text-align:center}.stats span{display:block;color:var(--muted);font-size:.72rem;text-transform:uppercase;letter-spacing:.1em}.stats strong{font-size:1.5rem}
#game,.game{--accent:#6cf2c2;--ink:#f6f8ff;--muted:#a8b3c8;position:relative;background:linear-gradient(160deg,#16223c,#0a1120);border:1px solid #ffffff14;border-radius:22px;padding:14px;display:flex;justify-content:center}
.grid{display:grid;gap:4px;width:min(420px,84vw,62vh);aspect-ratio:1/1}
.pipe-cell{position:relative;border-radius:8px;background:linear-gradient(155deg,#121c30,#0a1120);cursor:pointer;overflow:hidden;border:1px solid #ffffff12;touch-action:manipulation;-webkit-tap-highlight-color:transparent;transition:transform .1s ease,border-color .2s ease}
.pipe-cell:active:not(:disabled){transform:scale(.93)}
.pipe-cell.source,.pipe-cell.target{cursor:default}
.pipe-icon{position:absolute;inset:0;transition:transform .15s}
.arm{position:absolute;background:linear-gradient(155deg,#4b5f7d,#33445c);border-radius:3px}
.arm.n{left:41%;top:0;width:18%;height:55%}
.arm.e{top:41%;right:0;height:18%;width:55%}
.arm.s{left:41%;bottom:0;width:18%;height:55%}
.arm.w{top:41%;left:0;height:18%;width:55%}
.hub{position:absolute;left:32%;top:32%;width:36%;height:36%;border-radius:50%;background:radial-gradient(circle at 35% 30%,#5a7093,#33445c 70%)}
.pipe-cell.connected .arm{background:linear-gradient(155deg,color-mix(in srgb,var(--accent) 85%,white),var(--accent));box-shadow:0 0 8px color-mix(in srgb,var(--accent) 60%,transparent)}
.pipe-cell.connected .hub{background:radial-gradient(circle at 35% 30%,#fff,var(--accent) 65%);box-shadow:0 0 10px color-mix(in srgb,var(--accent) 70%,transparent)}
.pipe-cell.source .hub{background:radial-gradient(circle at 35% 30%,#fff,var(--accent) 60%);box-shadow:0 0 14px var(--accent);animation:sourcePulse 1.8s ease-in-out infinite}
@keyframes sourcePulse{0%,100%{box-shadow:0 0 10px var(--accent)}50%{box-shadow:0 0 20px var(--accent)}}
/* Target cells read as an actual diamond gem, not a generic pipe hub */
.pipe-cell.target .hub{border-radius:0;width:44%;height:44%;left:28%;top:28%;background:none;clip-path:polygon(50% 4%,90% 38%,74% 96%,26% 96%,10% 38%);background:linear-gradient(155deg,#ffe6a0,#ffd166 55%,#c98f1f);box-shadow:0 0 10px #ffd16699}
.pipe-cell.target.connected .hub{background:linear-gradient(155deg,#eafff6,var(--accent) 55%,#2b9d82);box-shadow:0 0 14px color-mix(in srgb,var(--accent) 80%,transparent)}
/* Key targets read as a distinct gold gem so they stand out from ordinary
   diamonds - they're the one target that must be solved first. */
.pipe-cell.target.key .hub{background:linear-gradient(155deg,#fff6d8,#ffcc33 55%,#b8860b);box-shadow:0 0 12px #ffcc3399}
.pipe-cell.target.key.connected .hub{background:linear-gradient(155deg,#fff,var(--accent) 55%,#2b9d82);box-shadow:0 0 16px color-mix(in srgb,var(--accent) 85%,transparent)}
.key-mark{position:absolute;top:2px;right:2px;font-size:.55rem;line-height:1;filter:drop-shadow(0 1px 1px #00000080)}
/* Locked targets stay visually dimmed/greyed until a key target opens them -
   the padlock overlay is the main cue, dimming reinforces "not reachable yet". */
.pipe-cell.target.locked-target:not(.connected) .hub{background:linear-gradient(155deg,#8a93a3,#4a5568 55%,#2d3341);box-shadow:none;opacity:.55}
.pipe-cell.target.locked-target.connected .hub{background:linear-gradient(155deg,#eafff6,var(--accent) 55%,#2b9d82);box-shadow:0 0 14px color-mix(in srgb,var(--accent) 80%,transparent)}
.lock-mark{position:absolute;top:2px;right:2px;font-size:.55rem;line-height:1;filter:drop-shadow(0 1px 1px #00000080)}
.pipe-cell.target.locked-target.connected .lock-mark{display:none}
.pipe-cell.obstacle{cursor:not-allowed;background:linear-gradient(155deg,#2a2622,#17140f);border-color:#00000030}
.pipe-cell.obstacle .rock{position:absolute;inset:18%;border-radius:20% 40% 30% 45%/40% 25% 45% 30%;background:linear-gradient(155deg,#6b5f4f,#3a3226);box-shadow:inset 0 0 0 1px #00000040,0 2px 4px #00000060}
.header-btns{display:flex;gap:8px;flex-wrap:wrap}
.stats strong.score-pop{animation:scorepop .5s ease}
@keyframes scorepop{0%{transform:scale(1.4);color:var(--accent)}100%{transform:scale(1)}}
:focus-visible{outline:3px solid var(--accent);outline-offset:2px}
.actions{display:flex;align-items:center;gap:18px;margin-top:14px;flex-wrap:wrap}.actions p{color:var(--muted);margin:0;min-width:0;flex:1 1 100%}button,a{font:inherit}#start{border:0;border-radius:999px;background:var(--accent);color:#fff;font-weight:850;padding:12px 20px;cursor:pointer;transition:background .15s}#start:hover:not(:disabled){background:color-mix(in srgb,var(--accent) 88%,black)}.quiet{background:#f1f5f9;color:#334155;white-space:nowrap;border:0;border-radius:999px;padding:12px 20px;cursor:pointer;transition:background .15s}.quiet:hover:not(:disabled){background:#e2e8f0}footer{display:flex;justify-content:space-between;gap:20px;color:var(--muted);font-size:.84rem;margin-top:28px}a{color:var(--accent);text-decoration:none}dialog{max-width:440px;max-height:88vh;overflow-y:auto;border:1px solid #e2e8f0;border-radius:22px;background:#fff;color:var(--ink);padding:28px;box-shadow:0 30px 100px rgba(15,23,42,.18)}dialog::backdrop{background:rgba(15,23,42,.45)}dialog button{margin-top:12px;min-height:44px}@media(max-width:600px){.shell{padding:max(10px,env(safe-area-inset-top)) max(10px,env(safe-area-inset-right)) max(10px,env(safe-area-inset-bottom)) max(10px,env(safe-area-inset-left))}header{display:block}.quiet{margin-top:8px}.stats strong{font-size:1.15rem}}@media(prefers-reduced-motion:reduce){.pipe-icon{transition:none}.stats strong.score-pop{animation:none}}
footer a:first-child{color:var(--ink);font-weight:700}
footer a.quiet-link{color:var(--muted)}

/* Campaign mode: tabs, level select, objective bar, dialogs */
.mode-tabs{display:flex;gap:8px;margin-top:18px}
.tab{flex:1;border:1px solid #e2e8f0;background:#f8fafc;color:var(--muted);border-radius:999px;padding:10px 14px;font-weight:800;cursor:pointer;font-size:.92rem}
.tab.active{background:var(--accent);color:#fff;border-color:transparent}
.level-select{margin-top:16px;display:flex;flex-direction:column;gap:16px}
.chapter-title{font-size:.95rem;margin:0 0 8px;color:var(--ink);letter-spacing:.02em;display:flex;align-items:center;gap:8px}
.difficulty-chip{display:inline-block;padding:2px 8px;border-radius:999px;font-size:.65rem;font-weight:800;text-transform:uppercase;letter-spacing:.05em}
.diff-easy{background:rgba(52,211,153,.18);color:#0f9d68}
.diff-medium{background:rgba(96,165,250,.18);color:#2563eb}
.diff-hard{background:rgba(251,191,36,.18);color:#b45309}
.diff-expert{background:rgba(251,146,60,.18);color:#c2410c}
.diff-master{background:rgba(244,63,94,.18);color:#be123c}
.level-row{display:grid;grid-template-columns:repeat(auto-fill,minmax(84px,1fr));gap:10px}
.level-btn{display:flex;flex-direction:column;align-items:center;gap:4px;border:1px solid #e2e8f0;background:#f8fafc;color:var(--ink);border-radius:16px;padding:12px 8px;cursor:pointer;min-height:76px;transition:transform .12s,background .12s}
.level-btn:hover:not(:disabled){transform:translateY(-2px);background:#eef2ff}
.level-btn.cleared{border-color:color-mix(in srgb,var(--accent) 55%,transparent)}
.level-btn.locked{opacity:.45;cursor:not-allowed}
.level-num{font-size:1.15rem;font-weight:900}
.level-kind{font-size:.68rem;color:var(--muted)}
.level-stars{font-size:.85rem;letter-spacing:.05em;color:#d99a1f}
.objective{margin-top:14px;background:#f8fafc;border:1px solid #e2e8f0;border-radius:16px;padding:12px 16px}
.obj-row{display:flex;justify-content:space-between;align-items:center;font-size:.9rem;gap:10px}
.objective p#obj-text{margin:6px 0;color:var(--muted);font-size:.85rem}
.obj-help{flex-shrink:0;width:26px;height:26px;border-radius:50%;border:1px solid #e2e8f0;background:#f1f5f9;color:var(--ink);font-weight:800;font-size:.8rem;cursor:pointer;padding:0;line-height:1;touch-action:manipulation}
.obj-help:hover,.obj-help[aria-expanded="true"]{background:var(--accent);color:#fff;border-color:transparent}
.obj-help-text{margin:2px 0 6px;color:var(--muted);font-size:.8rem;line-height:1.4;background:#f1f5f9;border-radius:10px;padding:8px 10px}
.progress-bar{height:8px;border-radius:999px;background:#e2e8f0;overflow:hidden}
.progress-bar .fill{height:100%;background:var(--accent);width:0;transition:width .25s ease}
/* Victory & Level-Up Popup Redesign System */
dialog#levelup, dialog#level-failed, dialog.victory-modal {
  max-width: 440px;
  width: min(92vw, 440px);
  border: 1px solid color-mix(in srgb, var(--ink, #fff) 15%, transparent);
  border-radius: 24px;
  background: var(--panel-bg, #0f172a);
  color: var(--ink, #f8fafc);
  padding: 24px;
  box-shadow: 0 30px 90px rgba(0, 0, 0, 0.6), 0 0 1px rgba(255, 255, 255, 0.2);
}

.victory-header {
  text-align: center;
  margin-bottom: 12px;
}

.victory-badge-icon {
  font-size: 2.8rem;
  line-height: 1;
  margin-bottom: 6px;
  filter: drop-shadow(0 4px 12px var(--accent-glow, rgba(56, 189, 248, 0.4)));
}

#levelup-title, #level-failed-title {
  margin: 0;
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--ink, #f8fafc);
  letter-spacing: -0.01em;
  text-align: center;
}

.stars-display {
  font-size: 2rem;
  letter-spacing: 0.2em;
  color: #fbbf24;
  text-align: center;
  margin: 8px 0 14px;
  filter: drop-shadow(0 0 12px rgba(251, 191, 36, 0.4));
}

.levelup-msg-card {
  background: color-mix(in srgb, var(--ink, #fff) 6%, transparent);
  border: 1px solid color-mix(in srgb, var(--ink, #fff) 10%, transparent);
  border-radius: 16px;
  padding: 14px 16px;
  margin-bottom: 18px;
  text-align: center;
}

.levelup-msg-card p, #levelup-msg, #level-failed-msg {
  margin: 0;
  color: var(--muted, #cbd5e1);
  font-size: 0.92rem;
  line-height: 1.5;
}

.dialog-actions {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-top: 16px;
  width: 100%;
}

.btn-next-level, .dialog-actions button#levelup-next, .dialog-actions button#level-failed-retry {
  width: 100%;
  min-height: 48px;
  border: 0;
  border-radius: 999px;
  background: var(--accent, #38bdf8);
  color: #ffffff;
  font-weight: 800;
  font-size: 1rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  box-shadow: 0 4px 20px var(--accent-glow, rgba(56, 189, 248, 0.35));
  transition: transform 0.15s ease, background 0.15s ease;
}

.btn-next-level:hover, .dialog-actions button#levelup-next:hover, .dialog-actions button#level-failed-retry:hover {
  transform: translateY(-2px);
  filter: brightness(1.08);
}

.secondary-actions-row {
  display: flex;
  gap: 8px;
  width: 100%;
}

.secondary-actions-row button,
.btn-secondary {
  flex: 1;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 10px 14px;
  border-radius: 999px;
  border: 1px solid color-mix(in srgb, var(--ink, #fff) 14%, transparent);
  background: color-mix(in srgb, var(--ink, #fff) 8%, transparent);
  color: var(--ink, #f8fafc);
  font-weight: 700;
  font-size: 0.88rem;
  cursor: pointer;
  white-space: nowrap;
  transition: background 0.15s ease, transform 0.15s ease;
}

.secondary-actions-row button:hover,
.btn-secondary:hover {
  background: color-mix(in srgb, var(--ink, #fff) 16%, transparent);
  transform: translateY(-1px);
}

.btn-more-games {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  min-height: 44px;
  padding: 10px 16px;
  border-radius: 999px;
  border: 1px solid color-mix(in srgb, var(--accent, #38bdf8) 35%, transparent);
  background: color-mix(in srgb, var(--accent, #38bdf8) 12%, transparent);
  color: var(--accent, #38bdf8);
  font-weight: 800;
  font-size: 0.88rem;
  text-decoration: none;
  transition: background 0.15s ease, transform 0.15s ease;
}

.btn-more-games:hover {
  background: color-mix(in srgb, var(--accent, #38bdf8) 22%, transparent);
  transform: translateY(-1px);
}
.pipe-cell.just-connected{animation:pipeConnect .4s ease}
@keyframes pipeConnect{0%{transform:scale(1)}40%{transform:scale(1.18)}100%{transform:scale(1)}}
.pipe-cell.hinted{animation:hintFlash 1s ease}
@keyframes hintFlash{0%,100%{box-shadow:none}30%{box-shadow:0 0 0 3px #ffd166}}
@media(prefers-reduced-motion:reduce){.pipe-cell.hinted{animation:none;box-shadow:0 0 0 3px #ffd166}}
.level-btn{touch-action:manipulation;-webkit-tap-highlight-color:transparent}
.level-btn:active:not(:disabled){transform:scale(.96)}
@media(max-width:600px){.level-row{grid-template-columns:repeat(auto-fill,minmax(72px,1fr))}.mode-tabs{flex-direction:column}}
@media(prefers-reduced-motion:reduce){.level-btn{transition:none}.pipe-cell.just-connected{animation:none}.progress-bar .fill{transition:none}}

/* Hold-the-finished-board celebration before the level-complete popup */
.grid.solved-glow .pipe-cell.connected{animation:solvedShimmer 1.1s ease-in-out infinite}
@keyframes solvedShimmer{0%,100%{filter:brightness(1)}50%{filter:brightness(1.45)}}
.solved-banner{position:absolute;left:50%;top:10px;transform:translateX(-50%);background:color-mix(in srgb,var(--accent) 22%,#0a1120);border:1px solid color-mix(in srgb,var(--accent) 55%,transparent);color:var(--ink);font-weight:900;font-size:1rem;padding:8px 18px;border-radius:999px;box-shadow:0 10px 30px #0007;animation:bannerPop .35s ease;pointer-events:none;z-index:2}
@keyframes bannerPop{0%{opacity:0;transform:translateX(-50%) translateY(-8px) scale(.9)}100%{opacity:1;transform:translateX(-50%) translateY(0) scale(1)}}
@media(prefers-reduced-motion:reduce){.grid.solved-glow .pipe-cell.connected{animation:none}.solved-banner{animation:none}}
[hidden]{display:none!important}

/* Guided tutorial: a glowing ring pinned over a live game element via JS
   (getBoundingClientRect), plus a callout bubble - no full dark backdrop
   blocking clicks, so the spotlighted element stays interactive underneath. */
.guided-tutorial{position:fixed;inset:0;z-index:50;pointer-events:none}
.guided-tutorial[hidden]{display:none}
.tutorial-spotlight{position:absolute;border-radius:16px;box-shadow:0 0 0 4px var(--accent),0 0 0 999px rgba(15,23,42,.55),0 0 26px var(--accent);transition:top .25s ease,left .25s ease,width .25s ease,height .25s ease;animation:tutorialPulse 1.3s ease-in-out infinite}
@keyframes tutorialPulse{0%,100%{box-shadow:0 0 0 4px var(--accent),0 0 0 999px rgba(15,23,42,.55),0 0 26px var(--accent)}50%{box-shadow:0 0 0 6px var(--accent),0 0 0 999px rgba(15,23,42,.55),0 0 40px var(--accent)}}
.tutorial-callout{position:absolute;width:min(320px,calc(100vw - 32px));padding:16px;border:1px solid #e2e8f0;border-radius:16px;background:#fff;box-shadow:0 20px 60px rgba(15,23,42,.22);pointer-events:auto;transition:top .25s ease,left .25s ease}
.tutorial-callout-step{display:block;margin-bottom:6px;color:var(--accent);font-size:.68rem;font-weight:900;letter-spacing:.12em;text-transform:uppercase}
.tutorial-callout p{margin:0 0 12px;color:var(--ink);line-height:1.45;font-size:.92rem}
.tutorial-callout button{min-height:40px;padding:0 16px;font-size:.85rem}
.tutorial-callout #tutorial-callout-next{margin-right:8px}
@media(prefers-reduced-motion:reduce){.tutorial-spotlight{animation:none}}

button, .actions button, .header-btns button, .icon-button {
  min-height: 44px;
  min-width: 44px;
}

.share-icons {
  display: flex;
  gap: 8px;
}

.game-area {
  position: relative;
}

.fullscreen-toggle {
  position: absolute;
  top: 8px;
  right: 8px;
  z-index: 5;
  width: 40px;
  height: 40px;
  min-width: 40px;
  min-height: 40px;
  border: 0;
  border-radius: 999px;
  background: rgba(15, 23, 42, 0.55);
  color: #fff;
  font-size: 17px;
  line-height: 1;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  backdrop-filter: blur(6px);
  transition: background 0.15s;
}

.fullscreen-toggle:hover {
  background: rgba(15, 23, 42, 0.75);
}

.fullscreen-toggle[aria-pressed="true"] {
  background: color-mix(in srgb, var(--accent, #5539de) 70%, rgba(15, 23, 42, 0.6));
}

.game-area:fullscreen,
.game-area:-webkit-full-screen {
  display: flex;
  align-items: center;
  justify-content: center;
  background: #0a1120;
  padding: max(16px, env(safe-area-inset-top)) max(16px, env(safe-area-inset-right))
    max(16px, env(safe-area-inset-bottom)) max(16px, env(safe-area-inset-left));
}

.game-area:fullscreen #game,
.game-area:-webkit-full-screen #game {
  width: min(92vw, 92vh, 720px);
  max-height: 92vh;
}

@media (prefers-reduced-motion: reduce) {
  .fullscreen-toggle {
    transition: none;
  }
}

.icon-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 44px;
  min-height: 44px;
  padding: 0;
}