/* ============================================================
   LogicLab — light theme, CSS-variable driven
   ============================================================ */
:root {
  /* Surfaces */
  --bg-0: #eef2f9; /* app / canvas backdrop */
  --bg-1: #ffffff; /* sidebar + panels */
  --bg-2: #f3f6fc; /* chips + buttons */
  --bg-3: #e7edf7; /* hover */
  --stroke: #d5deec;
  --stroke-soft: #e4eaf3;

  /* Text */
  --text-0: #1b2436;
  --text-1: #56617a;
  --text-2: #8a94a8;

  /* Accents */
  --accent: #4f7dff;
  --accent-strong: #3765f0;
  --power: #10b981; /* "live" / logic-high signal */
  --power-glow: rgba(16, 185, 129, 0.35);
  --danger: #ef4757;
  --warn: #f0a020;

  /* Geometry */
  --radius: 14px;
  --radius-sm: 9px;
  --sidebar-w: 288px;
  --shadow: 0 12px 30px rgba(31, 45, 70, 0.12);

  color-scheme: light;
}

* {
  box-sizing: border-box;
}

/* Visually hidden, but available to screen readers. */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  border: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
}

html,
body {
  margin: 0;
  height: 100%;
  overflow: hidden;
  font-family:
    "Poppins",
    "Segoe UI",
    system-ui,
    -apple-system,
    sans-serif;
  background: var(--bg-0);
  color: var(--text-0);
  -webkit-font-smoothing: antialiased;
}

/* ---------- App shell (Flexbox) ---------- */
.app {
  display: flex;
  height: 100vh;
  width: 100vw;
}

/* ============================================================
   Sidebar
   ============================================================ */
.sidebar {
  width: var(--sidebar-w);
  flex: 0 0 var(--sidebar-w);
  display: flex;
  flex-direction: column;
  gap: 18px;
  padding: 20px 18px;
  background: linear-gradient(180deg, var(--bg-1), var(--bg-0));
  border-right: 1px solid var(--stroke-soft);
  overflow-y: auto;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
}
.brand__mark {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border-radius: 13px;
  box-shadow: 0 6px 16px rgba(79, 125, 255, 0.32);
}
.brand__mark svg {
  display: block;
}
.brand__text h1 {
  margin: 0;
  font-size: 19px;
  font-weight: 700;
  letter-spacing: 0.2px;
}
.brand__text p {
  margin: 2px 0 0;
  font-size: 12px;
  color: var(--text-2);
}

.panel {
  background: var(--bg-1);
  border: 1px solid var(--stroke-soft);
  border-radius: var(--radius);
  padding: 14px;
}
.panel__title {
  margin: 0 0 4px;
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 1.2px;
  color: var(--text-2);
}
.panel__hint {
  margin: 0 0 12px;
  font-size: 12px;
  color: var(--text-2);
  line-height: 1.4;
}

/* ---------- Component palette ---------- */
.palette {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}

.panel__hint kbd {
  padding: 1px 6px;
  border-radius: 5px;
  border: 1px solid var(--stroke);
  background: var(--bg-0);
  font-size: 11px;
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  color: var(--text-1);
}

.chip {
  display: flex;
  align-items: center;
  gap: 10px;
  width: 100%;
  padding: 9px 10px;
  border: 1px solid var(--stroke);
  border-radius: var(--radius-sm);
  background: var(--bg-2);
  color: var(--text-0);
  font-size: 14px;
  cursor: pointer;
  transition:
    transform 0.08s ease,
    border-color 0.15s ease,
    background 0.15s ease;
}
.chip:hover {
  border-color: var(--accent);
  background: var(--bg-3);
}
.chip:active {
  transform: translateY(1px);
}
.chip.is-armed {
  border-color: var(--accent-strong);
  background: rgba(79, 125, 255, 0.12);
  box-shadow: inset 0 0 0 1px var(--accent);
}
.chip__icon {
  display: grid;
  place-items: center;
  width: 28px;
  height: 28px;
  border-radius: 6px;
  background: var(--bg-0);
  border: 1px solid var(--stroke);
  font-weight: 700;
  font-size: 14px;
  color: var(--accent-strong);
  flex-shrink: 0;
}
.chip__icon svg {
  width: 18px;
  height: 18px;
}
.chip__icon--switch {
  color: var(--warn);
}
.chip__icon--led {
  color: var(--power);
}
.chip__label {
  flex: 1;
  text-align: left;
}

/* ---------- Action buttons ---------- */
.actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 10px 12px;
  border: 1px solid var(--stroke);
  border-radius: var(--radius-sm);
  background: var(--bg-2);
  color: var(--text-0);
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  transition:
    border-color 0.15s ease,
    background 0.15s ease,
    transform 0.08s ease;
}
.btn:hover {
  border-color: var(--accent);
  background: var(--bg-3);
}
.btn:active {
  transform: translateY(1px);
}
.btn svg {
  width: 16px;
  height: 16px;
  flex: 0 0 auto;
}
.btn--primary {
  grid-column: span 2;
  background: linear-gradient(135deg, var(--accent), #6a5cff);
  border-color: transparent;
  color: #fff;
}
.btn--primary:hover {
  filter: brightness(1.08);
}
.btn--danger:hover {
  border-color: var(--danger);
  color: var(--danger);
}
.btn--wide {
  grid-column: span 2;
}

/* ---------- Toggle rows (View panel) ---------- */
.toggle {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 8px;
  font-size: 13px;
  color: var(--text-1);
  cursor: pointer;
  user-select: none;
}
.toggle input {
  accent-color: var(--accent);
  width: 15px;
  height: 15px;
  cursor: pointer;
}

/* ---------- Right-click context menu ---------- */
.context-menu {
  position: absolute;
  z-index: 30;
  min-width: 150px;
  padding: 5px;
  display: none;
  flex-direction: column;
  gap: 1px;
  background: var(--bg-1);
  border: 1px solid var(--stroke);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow);
}
.context-menu.is-open {
  display: flex;
}
.context-menu button {
  text-align: left;
  padding: 8px 10px;
  border: none;
  border-radius: 6px;
  background: transparent;
  color: var(--text-0);
  font-size: 13px;
  font-family: inherit;
  cursor: pointer;
}
.context-menu button:hover {
  background: var(--bg-3);
}
.context-menu button.danger:hover {
  background: rgba(255, 107, 107, 0.14);
  color: var(--danger);
}
.context-menu hr {
  border: none;
  border-top: 1px solid var(--stroke-soft);
  margin: 4px 2px;
}

/* ---------- Saved-circuit gallery ---------- */
.save-row {
  display: flex;
  gap: 8px;
  margin-bottom: 10px;
}
.text-input {
  flex: 1;
  min-width: 0;
  padding: 8px 10px;
  border: 1px solid var(--stroke);
  border-radius: var(--radius-sm);
  background: var(--bg-0);
  color: var(--text-0);
  font-size: 13px;
  font-family: inherit;
}
.text-input:focus {
  outline: none;
  border-color: var(--accent);
}
.save-row .btn {
  flex: 0 0 auto;
}

.gallery {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.gallery__empty {
  font-size: 12px;
  color: var(--text-2);
  padding: 4px 2px;
}
.gallery__item {
  display: flex;
  align-items: center;
  gap: 6px;
  border: 1px solid var(--stroke-soft);
  border-radius: var(--radius-sm);
  background: var(--bg-2);
  overflow: hidden;
}
.gallery__load {
  flex: 1;
  min-width: 0;
  text-align: left;
  padding: 8px 10px;
  border: none;
  background: transparent;
  color: var(--text-0);
  font-size: 13px;
  font-family: inherit;
  cursor: pointer;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.gallery__load:hover {
  background: var(--bg-3);
}
.gallery__del {
  flex: 0 0 auto;
  width: 30px;
  align-self: stretch;
  border: none;
  border-left: 1px solid var(--stroke-soft);
  background: transparent;
  color: var(--text-2);
  cursor: pointer;
  font-size: 12px;
}
.gallery__del:hover {
  background: rgba(255, 107, 107, 0.12);
  color: var(--danger);
}

.sidebar__footer {
  margin-top: auto;
  font-size: 12px;
  color: var(--text-2);
  padding-top: 8px;
  border-top: 1px solid var(--stroke-soft);
}

/* ============================================================
   Viewport / canvas
   ============================================================ */
.viewport {
  position: relative;
  flex: 1 1 auto;
  overflow: hidden;
  background:
    radial-gradient(1200px 800px at 70% -10%, rgba(79, 140, 255, 0.08), transparent 60%), var(--bg-0);
}
#stage {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
  touch-action: none; /* let pointer events drive pan/zoom */
  cursor: crosshair;
}
#stage:focus-visible {
  outline: 2px solid var(--accent-strong);
  outline-offset: -2px;
}

/* ---------- Onboarding overlay banner ---------- */
.onboarding {
  position: absolute;
  top: 18px;
  left: 18px;
  max-width: 340px;
  padding: 16px 18px 14px;
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.9);
  border: 1px solid var(--stroke);
  backdrop-filter: blur(10px);
  box-shadow: var(--shadow);
  transition:
    opacity 0.35s ease,
    transform 0.35s ease;
}
.onboarding.is-hidden {
  opacity: 0;
  transform: translateY(-8px);
  pointer-events: none;
}
.onboarding h3 {
  margin: 0 0 10px;
  font-size: 14px;
  letter-spacing: 0.4px;
}
.onboarding ul {
  margin: 0;
  padding-left: 18px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  font-size: 12.5px;
  color: var(--text-1);
  line-height: 1.45;
}
.onboarding b {
  color: var(--text-0);
}
.onboarding i {
  color: var(--accent-strong);
  font-style: normal;
}
.onboarding kbd {
  padding: 1px 6px;
  border-radius: 5px;
  border: 1px solid var(--stroke);
  background: var(--bg-0);
  font-size: 11px;
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
}
.onboarding__close {
  position: absolute;
  top: 10px;
  right: 10px;
  width: 24px;
  height: 24px;
  border-radius: 6px;
  border: 1px solid transparent;
  background: transparent;
  color: var(--text-2);
  cursor: pointer;
  font-size: 12px;
}
.onboarding__close:hover {
  border-color: var(--stroke);
  color: var(--text-0);
}

/* ---------- Truth-table modal ---------- */
.modal {
  position: absolute;
  inset: 0;
  display: none;
  align-items: center;
  justify-content: center;
  padding: 24px;
  background: rgba(27, 36, 54, 0.38);
  backdrop-filter: blur(3px);
  z-index: 20;
}
.modal.is-open {
  display: flex;
}
.modal__card {
  width: min(92%, 560px);
  max-height: 82%;
  overflow: auto;
  background: var(--bg-1);
  border: 1px solid var(--stroke);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}
.modal__head {
  position: sticky;
  top: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 16px;
  background: var(--bg-1);
  border-bottom: 1px solid var(--stroke-soft);
}
.modal__head h3 {
  margin: 0;
  font-size: 15px;
  letter-spacing: 0.3px;
}
.modal__close {
  width: 26px;
  height: 26px;
  border-radius: 6px;
  border: 1px solid transparent;
  background: transparent;
  color: var(--text-2);
  cursor: pointer;
  font-size: 13px;
}
.modal__close:hover {
  border-color: var(--stroke);
  color: var(--text-0);
}
.modal__body {
  padding: 12px 16px 18px;
}
.modal__note {
  margin: 0 0 10px;
  font-size: 12px;
  color: var(--text-2);
}

.ttable {
  border-collapse: collapse;
  width: 100%;
  font-size: 13px;
}
.ttable th,
.ttable td {
  padding: 6px 10px;
  text-align: center;
  border-bottom: 1px solid var(--stroke-soft);
}
.ttable th {
  color: var(--text-2);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.6px;
  font-size: 11px;
}
.ttable .sep {
  border-left: 1px solid var(--stroke);
}
.ttable td.one {
  color: var(--power);
  font-weight: 700;
}
.ttable td.zero {
  color: var(--text-2);
}
.ttable tbody tr:hover {
  background: rgba(79, 140, 255, 0.06);
}

/* ---------- Toast notifications ---------- */
.toast-host {
  position: absolute;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  gap: 8px;
  align-items: center;
  pointer-events: none;
}
.toast {
  padding: 10px 16px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.97);
  border: 1px solid var(--stroke);
  color: var(--text-0);
  font-size: 13px;
  box-shadow: var(--shadow);
  animation:
    toast-in 0.25s ease,
    toast-out 0.3s ease forwards;
  animation-delay: 0s, 2.4s;
}
.toast--good {
  border-color: var(--power);
}
.toast--bad {
  border-color: var(--danger);
}
@keyframes toast-in {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}
@keyframes toast-out {
  to {
    opacity: 0;
    transform: translateY(-6px);
  }
}

/* ---------- Reduced motion ---------- */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
  .toast {
    animation: none;
  }
}