/* ─────────────────────────────────────────────
   Base Reset
───────────────────────────────────────────── */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

/* ─────────────────────────────────────────────
     Root Variables
  ───────────────────────────────────────────── */
:root {
  --bg: #0b0b14;
  --ui-bg: rgba(10, 10, 20, 0.85);
  --ui-border: #2a2a4a;
  --ui-text: #a0a0d0;
  --ui-text-dim: #44446a;
  --accent: #5e60ce;
  --sidebar-w: 220px;
  --font-pixel: "Courier New", monospace;
}

/* ─────────────────────────────────────────────
     Page Layout
  ───────────────────────────────────────────── */
html,
body {
  width: 100%;
  height: 100%;
  background: var(--bg);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

/* Canvas + sidebar sit side by side */
#layout {
  display: flex;
  gap: 16px;
}

/* ─────────────────────────────────────────────
     Canvas
  ───────────────────────────────────────────── */
#game-canvas {
  display: block;
  image-rendering: pixelated;
  image-rendering: crisp-edges;
  border: 2px solid var(--ui-border);
  box-shadow: 0 0 40px rgba(94, 96, 206, 0.2);
}

/* ─────────────────────────────────────────────
     Sidebar
  ───────────────────────────────────────────── */
#sidebar {
  width: var(--sidebar-w);
  min-height: 196px;
  background: rgba(12, 12, 24, 0.95);
  border: 1px solid var(--ui-border);
  padding: 14px 12px;
  font-family: var(--font-pixel);
  display: flex;
  flex-direction: column;
  gap: 10px;
}

#sidebar-title {
  font-size: 10px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: #5a5a8a;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--ui-border);
}

#sidebar-empty {
  font-size: 10px;
  color: var(--ui-text-dim);
  letter-spacing: 0.05em;
}

/* Rule list */
#rule-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

/* Individual rule card */
.rule-card {
  border: 1px solid var(--ui-border);
  padding: 8px 10px;
  display: flex;
  flex-direction: column;
  gap: 4px;
  transition: border-color 0.2s, background 0.2s;
  position: relative;
  overflow: hidden;
}

/* ── Inactive (not yet collected) ── */
.rule-card.inactive {
  background: rgba(20, 20, 35, 0.6);
  opacity: 0.5;
}

.rule-card.inactive .rule-name {
  color: #5a5a7a;
}

/* ── Active (collected) ── */
.rule-card.active {
  background: rgba(20, 20, 40, 0.9);
}

.rule-card.active::before {
  content: "";
  position: absolute;
  inset: 0;
  opacity: 0.06;
  background: var(--rule-color, #5e60ce);
  pointer-events: none;
}

.rule-card.active {
  border-color: var(--rule-color, #5e60ce);
  box-shadow: 0 0 10px -2px var(--rule-color, #5e60ce);
}

/* Rule icon + name row */
.rule-header {
  display: flex;
  align-items: center;
  gap: 7px;
}

.rule-icon {
  font-size: 14px;
  font-weight: bold;
  line-height: 1;
  font-family: var(--font-pixel);
  min-width: 14px;
  text-align: center;
}

.rule-name {
  font-size: 10px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ui-text);
  font-weight: bold;
}

/* Description */
.rule-desc {
  font-size: 9px;
  color: var(--ui-text-dim);
  letter-spacing: 0.05em;
  line-height: 1.5;
}

.rule-card.active .rule-desc {
  color: #8080aa;
}

/* Status badge */
.rule-status {
  font-size: 8px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin-top: 2px;
}

.rule-card.active .rule-status {
  color: var(--rule-color, #5e60ce);
}
.rule-card.inactive .rule-status {
  color: var(--ui-text-dim);
}

/* ─────────────────────────────────────────────
     UI Overlay (top bar)
  ───────────────────────────────────────────── */
#ui-overlay {
  position: fixed;
  bottom: 8px;
  left: calc(100vw - 116px);
  transform: translateX(-50%);
  display: flex;
  gap: 32px;
  background: var(--ui-bg);
  font-family: var(--font-pixel);
  font-size: 12px;
  color: var(--ui-text);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  pointer-events: none;
  z-index: 10;
  align-items: center;
  justify-content: space-around;
  height: 30px;
  width: 200px;
}

#level-name {
  color: var(--ui-text-dim);
}

/* ─────────────────────────────────────────────
     Controls Hint
  ───────────────────────────────────────────── */
#controls-hint {
  position: fixed;
  bottom: 16px;
  left: 50%;
  transform: translateX(-50%);
  font-family: var(--font-pixel);
  font-size: 11px;
  color: #3a3a5a;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  pointer-events: none;
}
/* ─────────────────────────────────────────────
     Screen Overlay
  ───────────────────────────────────────────── */
.screen {
  position: fixed;
  inset: 0;
  background: rgba(7, 7, 16, 0.92);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
  backdrop-filter: blur(3px);
  animation: screen-fade-in 0.3s ease;
}

.screen.hidden {
  display: none;
}

@keyframes screen-fade-in {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

.screen-panel {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  text-align: center;
  font-family: var(--font-pixel);
  animation: panel-rise 0.4s cubic-bezier(0.22, 1, 0.36, 1);
}

.screen-panel.hidden {
  display: none;
}

@keyframes panel-rise {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.screen-eyebrow {
  font-size: 10px;
  letter-spacing: 0.25em;
  text-transform: uppercase;
  color: #4a4a7a;
}

.screen-title {
  font-size: 42px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: #d0d0f0;
  line-height: 1.1;
  text-shadow: 0 0 40px rgba(94, 96, 206, 0.5), 0 2px 0 rgba(0, 0, 0, 0.6);
}

.screen-body {
  font-size: 11px;
  color: #5a5a8a;
  letter-spacing: 0.08em;
  line-height: 1.9;
  max-width: 340px;
}

.screen-btn {
  margin-top: 8px;
  padding: 10px 36px;
  background: transparent;
  border: 1px solid var(--accent);
  color: var(--accent);
  font-family: var(--font-pixel);
  font-size: 12px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  cursor: pointer;
  transition: background 0.15s, color 0.15s, box-shadow 0.15s;
}

.screen-btn:hover {
  background: var(--accent);
  color: #0b0b14;
  box-shadow: 0 0 20px rgba(94, 96, 206, 0.5);
}

.screen-hint {
  font-size: 10px;
  color: #2e2e4e;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

/* ── Restart level button (in UI overlay) ── */
#btn-restart-level {
  pointer-events: all;
  background: transparent;
  border: 1px solid #2a2a4a;
  color: #5a5a8a;
  font-family: var(--font-pixel);
  font-size: 10px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  padding: 3px 10px;
  cursor: pointer;
  transition: border-color 0.15s, color 0.15s;
}
#btn-restart-level:hover {
  border-color: var(--accent);
  color: var(--accent);
}