@import url("https://fonts.googleapis.com/css2?family=Inter:wght@400;600;700&display=swap");
@import url("https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@500;700;800&display=swap");

/* =====================================================================
   Theming — every color routes through a variable so the four themes
   (circuit / blueprint / terminal / breadboard) just swap the palette.
   Gate accent colors stay constant across themes so a gate is always
   recognizable (AND is always blue, etc.).
   ===================================================================== */
:root,
[data-theme="circuit"] {
  --bg1: #08140e; --bg2: #050b08; --bg-glow: rgba(43, 255, 176, 0.08);
  --grid: rgba(43, 255, 176, 0.05);
  --panel: #0e1d16; --panel-2: #11251b; --line: #1d3a2c;
  --txt: #d8f3e6; --muted: #6f9784;
  --on: #2bffb0; --glow: rgba(43, 255, 176, 0.8); --off: #294238; --wire-none: #32463c;
  --node-bg: #0c1a13; --node-border: #2c4a3c; --node-dim: #436256;
  --slot-bg: rgba(20, 40, 30, 0.55); --slot-border: #356450; --slot-txt: #4f7c68;
  --hot-bg: rgba(43, 255, 176, 0.16);
  --bulb: #ffd24a; --bulb-glow: rgba(255, 210, 74, 0.85);
  --bulb-off-bg: #10241a; --bulb-off-border: #2c4a3c; --bulb-off-color: #3c5b4e;
  --title: #eafff5; --title-glow: rgba(43, 255, 176, 0.35);
}
[data-theme="blueprint"] {
  --bg1: #0a1838; --bg2: #060e22; --bg-glow: rgba(92, 214, 255, 0.1);
  --grid: rgba(96, 170, 255, 0.11);
  --panel: #0e1c3a; --panel-2: #12244a; --line: #244166;
  --txt: #dcebff; --muted: #7e97c6;
  --on: #5cd6ff; --glow: rgba(92, 214, 255, 0.85); --off: #243a5e; --wire-none: #2c3f63;
  --node-bg: #0c1830; --node-border: #2a4470; --node-dim: #466089;
  --slot-bg: rgba(20, 35, 65, 0.55); --slot-border: #37568c; --slot-txt: #5f7caf;
  --hot-bg: rgba(92, 214, 255, 0.16);
  --bulb: #ffd24a; --bulb-glow: rgba(255, 210, 74, 0.85);
  --bulb-off-bg: #10203c; --bulb-off-border: #2a4470; --bulb-off-color: #466089;
  --title: #eaf4ff; --title-glow: rgba(92, 214, 255, 0.4);
}
[data-theme="terminal"] {
  --bg1: #120c04; --bg2: #0a0703; --bg-glow: rgba(255, 179, 71, 0.07);
  --grid: rgba(255, 176, 71, 0.06);
  --panel: #1a1206; --panel-2: #22180a; --line: #3a2a12;
  --txt: #ffd9a3; --muted: #9c7842;
  --on: #ffb347; --glow: rgba(255, 179, 71, 0.85); --off: #3d2c12; --wire-none: #4a3717;
  --node-bg: #180f04; --node-border: #3f2c10; --node-dim: #6b4d1f;
  --slot-bg: rgba(50, 35, 12, 0.5); --slot-border: #5a401a; --slot-txt: #7a5a28;
  --hot-bg: rgba(255, 179, 71, 0.16);
  --bulb: #fff0a8; --bulb-glow: rgba(255, 224, 138, 0.9);
  --bulb-off-bg: #1a1206; --bulb-off-border: #3f2c10; --bulb-off-color: #6b4d1f;
  --title: #ffe6b8; --title-glow: rgba(255, 179, 71, 0.4);
}
[data-theme="breadboard"] {
  --bg1: #e9e3d2; --bg2: #ddd5bf; --bg-glow: rgba(255, 255, 255, 0.45);
  --grid: rgba(120, 108, 78, 0.14);
  --panel: #f2ecdc; --panel-2: #e7dfca; --line: #cabf9f;
  --txt: #2c2a20; --muted: #80795f;
  --on: #1f9d57; --glow: rgba(31, 157, 87, 0.55); --off: #bcb69d; --wire-none: #c6bfa6;
  --node-bg: #fbf7ea; --node-border: #c7bc97; --node-dim: #9a9374;
  --slot-bg: rgba(255, 255, 255, 0.55); --slot-border: #b9ad88; --slot-txt: #8a8264;
  --hot-bg: rgba(31, 157, 87, 0.16);
  --bulb: #ffcf3a; --bulb-glow: rgba(255, 196, 40, 0.8);
  --bulb-off-bg: #efe8d6; --bulb-off-border: #c7bc97; --bulb-off-color: #a89f80;
  --title: #23351f; --title-glow: rgba(31, 157, 87, 0.28);
}

/* gate accent colors (constant across themes) */
:root {
  --AND: #4aa3ff; --OR: #45d39a; --XOR: #b88cff;
  --NAND: #ff9f45; --NOR: #2dd4bf; --XNOR: #ff7ab0;
}

* { box-sizing: border-box; }
html, body {
  margin: 0;
  min-height: 100vh;
  color: var(--txt);
  font-family: "Inter", sans-serif;
  background:
    radial-gradient(circle at 50% -10%, var(--bg-glow), transparent 55%),
    linear-gradient(var(--bg1), var(--bg2));
  background-attachment: fixed;
}
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  opacity: 0.6;
  background-image:
    linear-gradient(var(--grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid) 1px, transparent 1px);
  background-size: 26px 26px;
}

.wrap {
  position: relative;
  z-index: 1;
  max-width: 920px;
  margin: 0 auto;
  padding: 4.25rem 1rem 3rem;
}

/* back button — true top-left, matches other games */
.back-link {
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 99999;
  font: 700 13px/1 "JetBrains Mono", monospace;
  color: var(--txt);
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 9px 13px;
  text-decoration: none;
  -webkit-tap-highlight-color: transparent;
}
.back-link:hover { background: var(--panel-2); }

/* header */
.lg-header { text-align: center; margin-bottom: 1.1rem; }
.lg-title {
  font-family: "JetBrains Mono", monospace;
  font-weight: 800;
  font-size: 2rem;
  letter-spacing: 2px;
  margin: 0;
  color: var(--title);
  text-shadow: 0 0 18px var(--title-glow);
}
.lg-title b { color: var(--on); }
.subtitle {
  color: var(--muted);
  font-size: 0.9rem;
  margin: 0.35rem auto 0;
  max-width: 560px;
}

/* mode picker (segmented) */
.mode-bar {
  display: flex;
  gap: 0;
  justify-content: center;
  margin: 0 auto 0.9rem;
  width: fit-content;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 4px;
}
.mode-btn {
  cursor: pointer;
  font-family: "JetBrains Mono", monospace;
  font-weight: 700;
  font-size: 0.82rem;
  color: var(--muted);
  background: transparent;
  border: none;
  border-radius: 999px;
  padding: 0.5rem 1.1rem;
  transition: 0.15s;
}
.mode-btn:hover { color: var(--txt); }
.mode-btn.active {
  color: #06120d;
  background: var(--on);
  box-shadow: 0 0 12px var(--glow);
}

/* toggle-able inputs (Set-Inputs mode) */
.node.input.toggle { cursor: pointer; transition: box-shadow 0.12s, transform 0.1s; }
.node.input.toggle:hover { box-shadow: 0 0 0 2px var(--on); }
.node.input.toggle:active { transform: translate(-50%, -50%) scale(0.92); }
.node.gate.fixed { cursor: default; }

/* hud */
.hud {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-bottom: 0.6rem;
}
#levelName {
  font-family: "JetBrains Mono", monospace;
  font-weight: 700;
  font-size: 1rem;
}
#status { font-size: 0.9rem; font-weight: 600; color: var(--muted); }
#status.win { color: var(--on); text-shadow: 0 0 12px var(--glow); }

/* board */
#board {
  position: relative;
  width: 100%;
  background:
    radial-gradient(circle at 50% 50%, var(--bg-glow), transparent 70%),
    var(--panel);
  border: 1px solid var(--line);
  border-radius: 16px;
  overflow: hidden;
}
#wires { position: absolute; inset: 0; z-index: 1; }
.wire { fill: none; stroke-width: 4; stroke-linecap: round; }
.wire.w-on { stroke: var(--on); filter: drop-shadow(0 0 5px var(--glow)); }
.wire.w-off { stroke: var(--off); }
.wire.w-none { stroke: var(--wire-none); stroke-width: 3; stroke-dasharray: 5 7; }

#nodes { position: absolute; inset: 0; z-index: 2; }

.node {
  position: absolute;
  transform: translate(-50%, -50%);
  display: flex;
  align-items: center;
  justify-content: center;
  user-select: none;
}

/* inputs */
.node.input {
  width: 46px;
  height: 40px;
  border-radius: 9px;
  flex-direction: column;
  font-family: "JetBrains Mono", monospace;
  border: 2px solid var(--node-border);
  background: var(--node-bg);
}
.node.input .lbl { font-size: 9px; color: var(--muted); line-height: 1; margin-top: 3px; }
.node.input .bit { font-size: 18px; font-weight: 800; line-height: 1; }
.node.input.on { border-color: var(--on); box-shadow: 0 0 13px var(--glow); }
.node.input.on .bit { color: var(--on); }
.node.input.off .bit { color: var(--node-dim); }
.node.input.inactive {
  border-style: dashed;
  border-color: var(--slot-border);
  background: var(--slot-bg);
}
.node.input.inactive .bit { color: var(--slot-txt); }

/* gates */
.node.gate {
  width: 82px;
  height: 46px;
  border-radius: 11px;
  font-family: "JetBrains Mono", monospace;
  touch-action: none;
}
.node.gate.slot {
  border: 2px dashed var(--slot-border);
  background: var(--slot-bg);
  color: var(--slot-txt);
  cursor: copy;
}
.node.gate.slot .qmark { font-size: 22px; font-weight: 800; }
.node.gate.slot.hot {
  border-color: var(--on);
  background: var(--hot-bg);
  box-shadow: 0 0 16px var(--glow);
}
.node.gate.filled {
  position: absolute;
  flex-direction: column;
  gap: 1px;
  cursor: grab;
  color: #06120d;
  border: 2px solid rgba(255, 255, 255, 0.85);
  box-shadow: 0 3px 0 rgba(0, 0, 0, 0.35);
}
.node.gate.filled:active { cursor: grabbing; }
.node.gate.filled.hot { box-shadow: 0 0 0 3px var(--on), 0 0 16px var(--glow); }
.node.gate .gname { font-size: 14px; font-weight: 800; letter-spacing: 0.5px; }
.node.gate .gout {
  font-size: 10px;
  font-weight: 800;
  background: rgba(0, 0, 0, 0.28);
  border-radius: 5px;
  padding: 0 5px;
  line-height: 13px;
}

/* gate colors */
.g-AND { background: var(--AND); }
.g-OR { background: var(--OR); }
.g-XOR { background: var(--XOR); }
.g-NAND { background: var(--NAND); }
.g-NOR { background: var(--NOR); }
.g-XNOR { background: var(--XNOR); }

/* bulb */
.node.bulb {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: var(--bulb-off-bg);
  border: 2px solid var(--bulb-off-border);
  color: var(--bulb-off-color);
}
.node.bulb svg { fill: currentColor; }
.node.bulb.lit {
  background: radial-gradient(circle at 50% 40%, #fff6d6, var(--bulb));
  border-color: #fff0b8;
  color: #7a5a00;
  box-shadow: 0 0 26px var(--bulb-glow), 0 0 60px var(--bulb-glow);
  animation: bulbpop 0.3s ease;
}
@keyframes bulbpop { from { transform: translate(-50%, -50%) scale(1.25); } to { transform: translate(-50%, -50%) scale(1); } }

/* palette */
#palette {
  display: flex;
  gap: 0.55rem;
  flex-wrap: wrap;
  justify-content: center;
  margin: 1rem 0 0.4rem;
  min-height: 52px;
}
.chip {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  font-family: "JetBrains Mono", monospace;
  font-weight: 800;
  color: #06120d;
  border: 2px solid rgba(255, 255, 255, 0.85);
  border-radius: 11px;
  padding: 0.5rem 0.8rem;
  cursor: grab;
  touch-action: none;
  box-shadow: 0 3px 0 rgba(0, 0, 0, 0.35);
  transition: transform 0.1s ease, opacity 0.15s ease;
}
.chip:active { cursor: grabbing; transform: translateY(2px); }
.chip .ccount { font-size: 11px; background: rgba(0, 0, 0, 0.28); border-radius: 6px; padding: 1px 6px; }
.chip.empty { opacity: 0.28; pointer-events: none; filter: grayscale(0.6); }
.pal-empty { color: var(--muted); font-size: 0.85rem; align-self: center; }

.drag-ghost {
  position: fixed !important;
  transform: translate(-50%, -50%) scale(1.05);
  z-index: 100000;
  pointer-events: none;
  opacity: 0.95;
}

/* controls */
.controls {
  display: flex;
  gap: 0.5rem;
  justify-content: center;
  flex-wrap: wrap;
  margin-top: 0.8rem;
}
.btn {
  cursor: pointer;
  font-family: "JetBrains Mono", monospace;
  font-weight: 700;
  font-size: 0.85rem;
  color: var(--txt);
  background: var(--panel-2);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 0.55rem 1rem;
  transition: background 0.15s, border-color 0.15s, opacity 0.15s;
}
.btn:hover:not(:disabled) { background: var(--panel); border-color: var(--on); }
.btn:disabled { opacity: 0.35; cursor: not-allowed; }
.btn.active { border-color: var(--bulb); color: var(--bulb); }
.btn.primary { background: var(--on); color: #06120d; border-color: var(--on); }

#hint {
  text-align: center;
  color: var(--bulb);
  font-size: 0.85rem;
  max-width: 560px;
  margin: 0.7rem auto 0;
  opacity: 0;
  transition: opacity 0.2s;
}
#hint.show { opacity: 1; }

/* theme picker */
.theme-bar {
  display: flex;
  gap: 0.4rem;
  justify-content: center;
  align-items: center;
  flex-wrap: wrap;
  margin-top: 0.9rem;
}
.theme-bar .tlabel {
  font-family: "JetBrains Mono", monospace;
  font-size: 0.75rem;
  color: var(--muted);
  margin-right: 0.1rem;
}
.theme-btn {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  cursor: pointer;
  font-family: "JetBrains Mono", monospace;
  font-weight: 700;
  font-size: 0.74rem;
  color: var(--muted);
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 0.3rem 0.65rem;
  transition: 0.15s;
}
.theme-btn .sw {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  border: 1px solid rgba(255, 255, 255, 0.45);
}
.theme-btn:hover { border-color: var(--on); }
.theme-btn.active { color: var(--txt); border-color: var(--on); box-shadow: 0 0 10px var(--glow); }

/* level dots */
#levelDots {
  display: flex;
  gap: 0.4rem;
  justify-content: center;
  flex-wrap: wrap;
  margin-top: 1.1rem;
}
.dot {
  width: 30px;
  height: 30px;
  border-radius: 8px;
  font-family: "JetBrains Mono", monospace;
  font-weight: 800;
  font-size: 0.8rem;
  cursor: pointer;
  color: var(--muted);
  background: var(--panel);
  border: 1px solid var(--line);
  transition: 0.15s;
}
.dot.cur { color: #06120d; background: var(--on); border-color: var(--on); }
.dot.done { color: var(--on); border-color: var(--on); }
.dot.locked { opacity: 0.3; cursor: not-allowed; }
.dot:hover:not(.locked):not(.cur) { background: var(--panel-2); }

/* help panel */
#helpPanel {
  display: none;
  margin: 1rem auto 0;
  max-width: 560px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 1rem 1.2rem;
}
#helpPanel.show { display: block; }
#helpPanel h3 { margin: 0 0 0.6rem; font-family: "JetBrains Mono", monospace; }
.leg {
  display: grid;
  grid-template-columns: 64px 1fr;
  gap: 0.5rem;
  align-items: center;
  margin-bottom: 0.4rem;
  font-size: 0.85rem;
}
.leg b {
  text-align: center;
  font-family: "JetBrains Mono", monospace;
  color: #06120d;
  border-radius: 7px;
  padding: 3px 0;
}
.leg span { color: var(--muted); }
.leg.g-AND b { background: var(--AND); }
.leg.g-OR b { background: var(--OR); }
.leg.g-XOR b { background: var(--XOR); }
.leg.g-NAND b { background: var(--NAND); }
.leg.g-NOR b { background: var(--NOR); }
.leg.g-XNOR b { background: var(--XNOR); }
.leg-foot { color: var(--muted); font-size: 0.8rem; margin: 0.6rem 0 0; }

/* win banner */
#winBanner {
  position: fixed;
  left: 50%;
  bottom: 24px;
  transform: translateX(-50%) translateY(160%);
  z-index: 200;
  background: var(--panel);
  border: 2px solid var(--on);
  border-radius: 14px;
  padding: 0.8rem 1.1rem;
  display: flex;
  align-items: center;
  gap: 0.9rem;
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.6), 0 0 24px var(--glow);
  transition: transform 0.35s cubic-bezier(0.2, 0.8, 0.3, 1);
}
#winBanner.show { transform: translateX(-50%) translateY(0); }
#winMsg { font-family: "JetBrains Mono", monospace; font-weight: 700; color: var(--on); }

@media (max-width: 560px) {
  .lg-title { font-size: 1.6rem; }
  .node.gate { width: 70px; height: 42px; }
  .node.gate .gname { font-size: 12px; }
}