/* ==========================================================================
   Semantic Network & Prolog Studio — design system
   ========================================================================== */

:root {
  --ink-900: #13293d;
  --ink-700: #2c4a63;
  --ink-500: #5b7b9a;
  --ink-300: #9db4c0;
  --ink-100: #eaf2f8;

  --brand-600: #3454d1;
  --brand-500: #4C6FFF;
  --brand-400: #7b93ff;
  --brand-100: #e8ecff;

  --accent-teal: #0f9b8e;
  --accent-teal-100: #e3f7f5;
  --accent-amber: #e2920f;
  --accent-amber-100: #fdf1dd;
  --accent-rose: #d64550;
  --accent-rose-100: #fbe9ea;
  --accent-violet: #8450c7;
  --accent-violet-100: #f1e9fb;

  --surface-0: #ffffff;
  --surface-1: #f6f8fc;
  --surface-2: #eef1f8;
  --border: #dbe2ee;
  --border-strong: #c3cee0;

  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;

  --shadow-sm: 0 1px 2px rgba(19, 41, 61, 0.06), 0 1px 1px rgba(19, 41, 61, 0.08);
  --shadow-md: 0 6px 20px rgba(19, 41, 61, 0.10);
  --shadow-lg: 0 16px 40px rgba(19, 41, 61, 0.16);

  --font-ui: "Segoe UI", Inter, -apple-system, BlinkMacSystemFont, "Helvetica Neue", Arial, sans-serif;
  --font-mono: "Cascadia Code", "Fira Code", Consolas, "Courier New", monospace;
}

* { box-sizing: border-box; }

html, body {
  height: 100%;
  margin: 0;
  padding: 0;
}

body {
  font-family: var(--font-ui);
  color: var(--ink-900);
  background: var(--surface-1);
  overflow: hidden;
}

button {
  font-family: inherit;
}

svg text { user-select: none; }

::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border-strong); border-radius: 10px; }
::-webkit-scrollbar-thumb:hover { background: var(--ink-300); }

/* ---------- App shell ---------- */

#app {
  display: flex;
  flex-direction: column;
  height: 100vh;
}

.topbar {
  display: flex;
  align-items: center;
  gap: 24px;
  padding: 0 20px;
  height: 58px;
  background: var(--surface-0);
  border-bottom: 1px solid var(--border);
  flex: 0 0 auto;
  z-index: 50;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 16px;
  color: var(--ink-900);
  white-space: nowrap;
}

.brand .brand-mark {
  width: 30px;
  height: 30px;
  border-radius: 9px;
  background: linear-gradient(135deg, var(--brand-500), var(--accent-violet));
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  flex: 0 0 auto;
}

.tabs {
  display: flex;
  gap: 4px;
  background: var(--surface-2);
  border-radius: 999px;
  padding: 4px;
}

.tab-btn {
  display: flex;
  align-items: center;
  gap: 8px;
  border: none;
  background: transparent;
  color: var(--ink-500);
  font-weight: 600;
  font-size: 13.5px;
  padding: 8px 16px;
  border-radius: 999px;
  cursor: pointer;
  transition: background .15s ease, color .15s ease;
}

.tab-btn:hover { color: var(--ink-900); }

.tab-btn.active {
  background: var(--surface-0);
  color: var(--brand-600);
  box-shadow: var(--shadow-sm);
}

.tab-btn svg { width: 17px; height: 17px; }

.topbar-spacer { flex: 1; }

.topbar-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

.badge-autosave {
  font-size: 12px;
  color: var(--ink-500);
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 0 8px;
}

.badge-autosave .dot {
  width: 7px; height: 7px; border-radius: 50%;
  background: var(--accent-teal);
}

.lang-switch {
  width: 86px;
  flex: 0 0 auto;
}
.lang-switch button {
  padding: 6px 4px;
  letter-spacing: .02em;
}

/* ---------- Generic buttons ---------- */

.btn {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  border: 1px solid var(--border);
  background: var(--surface-0);
  color: var(--ink-900);
  font-size: 13px;
  font-weight: 600;
  padding: 8px 13px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all .12s ease;
  white-space: nowrap;
}

.btn svg { width: 16px; height: 16px; flex: 0 0 auto; }

.btn:hover { border-color: var(--border-strong); background: var(--surface-1); transform: translateY(-1px); box-shadow: var(--shadow-sm); }
.btn:active { transform: translateY(0); }

.btn-primary {
  background: var(--brand-500);
  border-color: var(--brand-500);
  color: white;
}
.btn-primary:hover { background: var(--brand-600); border-color: var(--brand-600); }

.btn-ghost {
  background: transparent;
  border-color: transparent;
}
.btn-ghost:hover { background: var(--surface-2); }

.btn-danger { color: var(--accent-rose); }
.btn-danger:hover { background: var(--accent-rose-100); border-color: var(--accent-rose-100); }

.btn-sm { padding: 6px 10px; font-size: 12.5px; }
.btn-icon { padding: 8px; }
.btn:disabled { opacity: .45; cursor: not-allowed; transform: none; box-shadow: none; }

.btn-toggle.active {
  background: var(--brand-100);
  border-color: var(--brand-400);
  color: var(--brand-600);
}

/* ---------- Views ---------- */

.view {
  flex: 1;
  min-height: 0;
  display: none;
}
.view.active { display: flex; }

/* ================= NETWORK DESIGNER ================= */

#view-network { position: relative; }

.net-toolbar {
  width: 86px;
  flex: 0 0 auto;
  background: var(--surface-0);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 14px 8px;
  gap: 6px;
  overflow-y: auto;
}

.tool-btn {
  width: 64px;
  height: 58px;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  background: transparent;
  color: var(--ink-700);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
  font-size: 10.5px;
  font-weight: 600;
  cursor: pointer;
  transition: all .12s ease;
}
.tool-btn svg { width: 20px; height: 20px; }
.tool-btn:hover { background: var(--surface-2); }
.tool-btn.active { background: var(--brand-100); color: var(--brand-600); border-color: var(--brand-400); }

.tool-sep { width: 60%; height: 1px; background: var(--border); margin: 6px 0; }

.net-canvas-wrap {
  flex: 1;
  position: relative;
  overflow: hidden;
  background:
    radial-gradient(var(--border-strong) 1px, transparent 1px);
  background-size: 22px 22px;
  background-color: var(--surface-1);
}

#network-svg {
  width: 100%;
  height: 100%;
  cursor: default;
}

#network-svg.mode-pan { cursor: grab; }
#network-svg.mode-pan:active { cursor: grabbing; }
#network-svg.mode-add-node { cursor: copy; }
#network-svg.mode-link { cursor: crosshair; }

.net-node-group { cursor: grab; }
.net-node-group:active { cursor: grabbing; }

.net-node-box {
  fill: var(--surface-0);
  stroke: var(--brand-500);
  stroke-width: 1.6;
  filter: drop-shadow(0 2px 4px rgba(19,41,61,.12));
}
.net-node-group.selected .net-node-box {
  stroke: var(--accent-rose);
  stroke-width: 2.4;
}
.net-node-label {
  font-family: var(--font-ui);
  font-size: 13px;
  font-weight: 600;
  fill: var(--ink-900);
  pointer-events: none;
}

.net-edge-path {
  fill: none;
  stroke: var(--ink-500);
  stroke-width: 2;
  cursor: pointer;
  pointer-events: none;
}
.net-edge-hit {
  fill: none;
  stroke: transparent;
  stroke-width: 14;
  cursor: pointer;
}
.net-edge-path.selected { stroke: var(--accent-rose); stroke-width: 2.6; }
.net-edge-label {
  font-family: var(--font-ui);
  font-size: 11px;
  font-weight: 600;
  fill: var(--ink-700);
  pointer-events: none;
}
.net-edge-label-bg {
  fill: var(--surface-1);
  opacity: .92;
  pointer-events: none;
}

.net-link-ghost {
  stroke: var(--brand-400);
  stroke-width: 2;
  stroke-dasharray: 5 4;
  fill: none;
  pointer-events: none;
}

.net-empty-hint {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  pointer-events: none;
  text-align: center;
  color: var(--ink-500);
  font-size: 14px;
  max-width: 360px;
  margin: auto;
  line-height: 1.5;
}
.net-empty-hint.hidden { display: none; }

.zoom-controls {
  position: absolute;
  right: 18px;
  bottom: 18px;
  display: flex;
  flex-direction: column;
  background: var(--surface-0);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-md);
  overflow: hidden;
}
.zoom-controls button {
  width: 36px; height: 36px;
  border: none;
  background: transparent;
  cursor: pointer;
  color: var(--ink-700);
  font-size: 16px;
  border-bottom: 1px solid var(--border);
}
.zoom-controls button:last-child { border-bottom: none; }
.zoom-controls button:hover { background: var(--surface-2); }

/* ---- Right inspector panel (network) ---- */

.net-inspector {
  width: 300px;
  flex: 0 0 auto;
  background: var(--surface-0);
  border-left: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  overflow-y: auto;
}

.inspector-section {
  padding: 16px;
  border-bottom: 1px solid var(--border);
}
.inspector-section h3 {
  margin: 0 0 12px;
  font-size: 12px;
  letter-spacing: .04em;
  text-transform: uppercase;
  color: var(--ink-500);
  display: flex;
  align-items: center;
  gap: 8px;
}

.field { margin-bottom: 12px; }
.field:last-child { margin-bottom: 0; }
.field label {
  display: block;
  font-size: 12px;
  font-weight: 600;
  color: var(--ink-700);
  margin-bottom: 5px;
}
.field input[type=text], .field select, .field textarea {
  width: 100%;
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-family: var(--font-ui);
  background: var(--surface-0);
  color: var(--ink-900);
}
.field input[type=text]:focus, .field select:focus, .field textarea:focus {
  outline: none;
  border-color: var(--brand-400);
  box-shadow: 0 0 0 3px var(--brand-100);
}
.field-row { display: flex; gap: 8px; }
.field-row .field { flex: 1; }

.swatches { display: flex; gap: 6px; flex-wrap: wrap; }
.swatch {
  width: 24px; height: 24px; border-radius: 50%;
  border: 2px solid var(--surface-0);
  box-shadow: 0 0 0 1px var(--border);
  cursor: pointer;
}
.swatch.selected { box-shadow: 0 0 0 2px var(--ink-900); }

.seg-control {
  display: flex;
  background: var(--surface-2);
  border-radius: var(--radius-sm);
  padding: 3px;
  gap: 3px;
}
.seg-control button {
  flex: 1;
  border: none;
  background: transparent;
  padding: 7px 4px;
  border-radius: 6px;
  font-size: 12px;
  font-weight: 600;
  color: var(--ink-500);
  cursor: pointer;
}
.seg-control button.active { background: var(--surface-0); color: var(--brand-600); box-shadow: var(--shadow-sm); }

.rel-chip-list { display: flex; flex-wrap: wrap; gap: 6px; }
.rel-chip {
  padding: 5px 10px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--surface-1);
  font-size: 12px;
  font-weight: 600;
  color: var(--ink-700);
  cursor: pointer;
}
.rel-chip:hover { border-color: var(--brand-400); }
.rel-chip.active { background: var(--brand-100); border-color: var(--brand-400); color: var(--brand-600); }

.empty-inspector {
  padding: 28px 18px;
  color: var(--ink-500);
  font-size: 13px;
  text-align: center;
  line-height: 1.6;
}

/* ---- Rule builder drawer ---- */

.rules-panel {
  flex: 1;
  min-height: 0;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}
.rules-panel-header {
  padding: 14px 16px 10px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.rules-panel-header h3 {
  margin: 0;
  font-size: 12px;
  letter-spacing: .04em;
  text-transform: uppercase;
  color: var(--ink-500);
}
.rules-list {
  flex: 1;
  overflow-y: auto;
  padding: 0 12px 12px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.rule-card {
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface-1);
  overflow: hidden;
}
.rule-card-head {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 9px 11px;
  background: var(--surface-0);
  border-bottom: 1px solid var(--border);
}
.rule-card-head .rule-title {
  flex: 1;
  font-family: var(--font-mono);
  font-size: 12.5px;
  font-weight: 700;
  color: var(--accent-violet);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.rule-card-body { padding: 10px 11px; }
.rule-preview {
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.6;
  color: var(--ink-900);
  background: var(--ink-100);
  border-radius: 6px;
  padding: 8px 10px;
  white-space: pre-wrap;
  word-break: break-word;
}
.rule-preview .pl-kw { color: var(--accent-rose); }
.rule-preview .pl-var { color: var(--brand-600); }
.rule-preview .pl-atom { color: var(--accent-teal); }

.cond-row {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-bottom: 6px;
  flex-wrap: wrap;
}
.cond-row select, .cond-row input[type=text] {
  padding: 5px 7px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 12px;
  font-family: var(--font-mono);
}
.cond-not-toggle {
  border: 1px solid var(--border);
  background: var(--surface-0);
  border-radius: 6px;
  font-size: 11px;
  font-weight: 700;
  padding: 5px 8px;
  cursor: pointer;
  color: var(--ink-500);
  font-family: var(--font-mono);
}
.cond-not-toggle.active { background: var(--accent-rose-100); border-color: var(--accent-rose); color: var(--accent-rose); }

/* ================= PROLOG IDE ================= */

#view-ide.active {
  display: flex;
}

.ide-sidebar {
  width: 230px;
  flex: 0 0 auto;
  background: #1c2430;
  color: #c7d2e3;
  display: flex;
  flex-direction: column;
  border-right: 1px solid #0f141c;
}
.ide-sidebar-section { padding: 14px 14px 8px; }
.ide-sidebar h4 {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: .06em;
  color: #7f8fab;
  margin: 10px 14px 8px;
}
.ide-file-list { padding: 0 8px; overflow-y: auto; flex: 1; }
.ide-file-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 7px 8px;
  border-radius: 7px;
  font-size: 13px;
  cursor: pointer;
  color: #c7d2e3;
}
.ide-file-item:hover { background: #28323f; }
.ide-file-item.active { background: #30405e; color: white; }
.ide-file-item svg { width: 15px; height: 15px; flex: 0 0 auto; opacity: .8; }

.ide-side-btn {
  display: flex;
  align-items: center;
  gap: 9px;
  width: 100%;
  background: transparent;
  border: none;
  color: #c7d2e3;
  padding: 9px 14px;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  border-radius: 8px;
  text-align: left;
}
.ide-side-btn:hover { background: #28323f; }
.ide-side-btn svg { width: 16px; height: 16px; opacity: .85; }

.ide-main {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.ide-editor-toolbar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  background: var(--surface-0);
  border-bottom: 1px solid var(--border);
}
.ide-filename {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 13px;
  color: var(--ink-900);
  margin-right: 6px;
}
.ide-dirty-dot { width: 7px; height: 7px; border-radius: 50%; background: var(--accent-amber); display: none; }
.ide-dirty-dot.show { display: inline-block; }

.ide-editor-wrap {
  flex: 1 1 55%;
  min-height: 0;
  position: relative;
}
.CodeMirror {
  height: 100% !important;
  font-family: var(--font-mono) !important;
  font-size: 14px !important;
  line-height: 1.55 !important;
}

.ide-console {
  flex: 1 1 45%;
  min-height: 140px;
  border-top: 1px solid var(--border);
  background: #11161d;
  display: flex;
  flex-direction: column;
  color: #e3e8f0;
}
.ide-console-header {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  border-bottom: 1px solid #262f3b;
  font-size: 12px;
  color: #8291a8;
  text-transform: uppercase;
  letter-spacing: .05em;
}
.ide-query-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 14px;
  border-bottom: 1px solid #262f3b;
}
.ide-query-bar .prompt { color: var(--accent-teal); font-family: var(--font-mono); font-weight: 700; }
.ide-query-input {
  flex: 1;
  background: #1c2430;
  border: 1px solid #2d394a;
  color: #e3e8f0;
  border-radius: 8px;
  padding: 8px 10px;
  font-family: var(--font-mono);
  font-size: 13.5px;
}
.ide-query-input:focus { outline: none; border-color: var(--brand-400); }

.ide-results {
  flex: 1;
  overflow-y: auto;
  padding: 10px 14px;
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.7;
}
.ide-result-line { white-space: pre-wrap; word-break: break-word; margin-bottom: 4px; }
.ide-result-line.ok { color: #7be0c4; }
.ide-result-line.query-echo { color: #8291a8; }
.ide-result-line.err { color: #ff8a80; }
.ide-result-line.info { color: #8291a8; font-style: italic; }
.ide-result-bindings { color: #e3e8f0; }
.ide-result-bindings .var { color: #82aaff; }

.ide-next-sol-row {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 2px 0 10px;
}
.ide-next-btn {
  background: #243041;
  border: 1px solid #334256;
  color: #cfe0ff;
  border-radius: 6px;
  padding: 4px 10px;
  font-size: 12px;
  font-family: var(--font-mono);
  cursor: pointer;
}
.ide-next-btn:hover { background: #2d3c52; }
.ide-next-btn:disabled { opacity: .4; cursor: not-allowed; }

/* ================= HELP ================= */

#view-help {
  overflow-y: auto;
  padding: 0;
  background: var(--surface-1);
}
#view-help.active {
  display: block;
}
.help-wrap {
  max-width: 880px;
  margin: 0 auto;
  padding: 40px 32px 90px;
}
.help-hero {
  text-align: center;
  margin-bottom: 36px;
}
.help-hero h1 {
  font-size: 28px;
  margin: 0 0 8px;
  color: var(--ink-900);
}
.help-hero p { color: var(--ink-500); font-size: 15px; }

.help-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: center;
  margin-bottom: 36px;
}
.help-nav a {
  text-decoration: none;
  font-size: 12.5px;
  font-weight: 600;
  color: var(--brand-600);
  background: var(--brand-100);
  padding: 7px 13px;
  border-radius: 999px;
}
.help-nav a:hover { background: var(--brand-400); color: white; }

.help-card {
  background: var(--surface-0);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 26px 28px;
  margin-bottom: 20px;
  box-shadow: var(--shadow-sm);
}
.help-card h2 {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 18px;
  margin: 0 0 14px;
  color: var(--ink-900);
}
.help-card h2 .icn {
  width: 34px; height: 34px;
  border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  color: white;
  flex: 0 0 auto;
}
.help-card p { line-height: 1.65; color: var(--ink-700); font-size: 14.5px; }
.help-card ul { line-height: 1.8; color: var(--ink-700); font-size: 14.5px; padding-left: 20px; }
.help-card li { margin-bottom: 6px; }
.help-card code {
  background: var(--ink-100);
  color: var(--ink-900);
  padding: 2px 6px;
  border-radius: 5px;
  font-family: var(--font-mono);
  font-size: 13px;
}
.help-kbd {
  display: inline-block;
  border: 1px solid var(--border-strong);
  border-bottom-width: 2px;
  background: var(--surface-1);
  border-radius: 5px;
  padding: 1px 7px;
  font-family: var(--font-mono);
  font-size: 12px;
}

.help-step-list { counter-reset: step; list-style: none; padding-left: 0; }
.help-step-list li {
  counter-increment: step;
  position: relative;
  padding-left: 34px;
  margin-bottom: 12px;
}
.help-step-list li::before {
  content: counter(step);
  position: absolute;
  left: 0; top: 0;
  width: 22px; height: 22px;
  border-radius: 50%;
  background: var(--brand-100);
  color: var(--brand-600);
  font-weight: 700;
  font-size: 12px;
  display: flex; align-items: center; justify-content: center;
}

/* ---------- Toast / dialog ---------- */

.toast-stack {
  position: fixed;
  right: 18px;
  bottom: 18px;
  display: flex;
  flex-direction: column-reverse;
  gap: 8px;
  z-index: 999;
}
.toast {
  background: var(--ink-900);
  color: white;
  padding: 11px 16px;
  border-radius: var(--radius-sm);
  font-size: 13px;
  box-shadow: var(--shadow-lg);
  display: flex;
  align-items: center;
  gap: 8px;
  animation: toast-in .18s ease;
  max-width: 340px;
}
.toast.error { background: var(--accent-rose); }
.toast.success { background: var(--accent-teal); }
@keyframes toast-in { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: translateY(0); } }

.modal-overlay {
  position: fixed; inset: 0;
  background: rgba(19,41,61,.45);
  display: flex; align-items: center; justify-content: center;
  z-index: 998;
}
.modal-overlay.hidden { display: none; }
.modal-box {
  background: var(--surface-0);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  width: 420px;
  max-width: 92vw;
  padding: 22px;
}
.modal-box h3 { margin: 0 0 6px; font-size: 16px; }
.modal-box p { margin: 0 0 16px; color: var(--ink-500); font-size: 13.5px; }
.modal-actions { display: flex; justify-content: flex-end; gap: 8px; margin-top: 18px; }

/* Visually hidden but accessible */
.sr-only {
  position: absolute; width: 1px; height: 1px;
  padding: 0; margin: -1px; overflow: hidden;
  clip: rect(0,0,0,0); white-space: nowrap; border: 0;
}

@media (max-width: 980px) {
  .net-inspector { width: 260px; }
  .ide-sidebar { width: 190px; }
}