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

:root {
  --bg: #0f1117;
  --bg2: #161b24;
  --bg3: #1e2535;
  --border: #2a3347;
  --accent: #4ade80;
  --accent2: #22c55e;
  --accent-dim: rgba(74,222,128,.15);
  --text: #e2e8f0;
  --text2: #94a3b8;
  --text3: #64748b;
  --red: #f87171;
  --amber: #fbbf24;
  --blue: #60a5fa;
  --wire-col: #c8a84b;
  --panel-w: 260px;
  --header-h: 54px;
  --radius: 8px;
  --radius-lg: 12px;
}

html, body { height: 100%; overflow: hidden; }
body {
  font-family: 'Segoe UI', system-ui, sans-serif;
  font-size: 13px;
  background: var(--bg);
  color: var(--text);
  display: flex;
  flex-direction: column;
}

/* ── Header ── */
#app-header {
  height: var(--header-h);
  background: var(--bg2);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 20px;
  flex-shrink: 0;
  z-index: 10;
}

.logo { display: flex; align-items: center; gap: 8px; }
.logo-icon { font-size: 22px; color: var(--accent); }
.logo-text { font-size: 16px; letter-spacing: -0.3px; color: var(--text2); }
h1.logo-text { margin: 0; font-weight: 400; }
.logo-text strong { color: var(--accent); font-weight: 700; }
/* visually hidden, still read by screen readers & crawlers */
.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;
}

/* ── Level / step switcher ── */
#step-tabs {
  display: flex;
  align-items: center;
  gap: 8px;
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
}
.step-tab {
  display: flex;
  align-items: center;
  gap: 7px;
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text2);
  padding: 5px 14px;
  border-radius: 20px;
  cursor: pointer;
  font-size: 12px;
  font-weight: 600;
  transition: border-color .2s, color .2s, background .2s;
}
.step-tab:hover { border-color: var(--accent); color: var(--text); }
.step-tab.active { border-color: var(--accent); background: var(--accent-dim); color: var(--accent); }
.step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 17px; height: 17px;
  border-radius: 50%;
  background: var(--bg3);
  font-size: 10px;
  font-weight: 700;
}
.step-tab.active .step-num { background: var(--accent); color: var(--bg); }
.step-sep { color: var(--text3); font-size: 12px; }

/* Level visibility: an element with data-level shows only on the stages it
   lists (space-separated, matched with ~=). No data-level → shown on all. */
body.level-1 [data-level]:not([data-level~="1"]) { display: none !important; }
body.level-2 [data-level]:not([data-level~="2"]) { display: none !important; }
body.level-3 [data-level]:not([data-level~="3"]) { display: none !important; }

/* Big step CTA at the bottom of the left panel */
.level-cta-wrap { position: sticky; bottom: 0; background: var(--bg2); border-top: 1px solid var(--border); }
.level-nav { display: flex; gap: 6px; }
.btn-level-cta {
  flex: 1;
  background: var(--accent);
  color: var(--bg);
  border: none;
  border-radius: var(--radius);
  padding: 11px 14px;
  font-size: 13px;
  font-weight: 700;
  cursor: pointer;
  transition: background .2s;
}
.btn-level-cta:hover { background: var(--accent2); }
.btn-level-back {
  background: var(--bg3);
  color: var(--text2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 11px 12px;
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
  white-space: nowrap;
  transition: border-color .2s, color .2s;
}
.btn-level-back:hover { border-color: var(--accent); color: var(--accent); }

.header-actions { display: flex; gap: 8px; }
.btn-ghost {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text2);
  padding: 6px 14px;
  border-radius: var(--radius);
  cursor: pointer;
  font-size: 12px;
  transition: border-color .2s, color .2s;
}
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); }
.btn-primary {
  background: var(--accent);
  border: none;
  color: #0f1117;
  padding: 6px 16px;
  border-radius: var(--radius);
  cursor: pointer;
  font-size: 12px;
  font-weight: 600;
  transition: background .2s;
}
.btn-primary:hover { background: var(--accent2); }

/* ── Main layout ── */
#app-layout {
  flex: 1;
  display: grid;
  grid-template-columns: var(--panel-w) 1fr var(--panel-w);
  overflow: hidden;
}

/* ── Panels ── */
aside {
  background: var(--bg2);
  border-right: 1px solid var(--border);
  overflow-y: auto;
  overflow-x: hidden;
  scrollbar-width: thin;
  scrollbar-color: var(--border) transparent;
}
#panel-right { border-right: none; border-left: 1px solid var(--border); }
aside::-webkit-scrollbar { width: 4px; }
aside::-webkit-scrollbar-thumb { background: var(--border); border-radius: 2px; }

.panel-section {
  padding: 14px 16px;
  border-bottom: 1px solid var(--border);
}
.section-title {
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 1px;
  text-transform: uppercase;
  color: var(--text3);
  margin-bottom: 12px;
}

/* ── Structure list (complex manager) ── */
#structure-list { display: flex; flex-direction: column; gap: 4px; margin-bottom: 8px; }
.structure-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 7px 9px;
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  transition: border-color .15s, background .15s;
  user-select: none;
}
.structure-item:hover { border-color: var(--accent); }
.structure-item.active { border-color: var(--accent); background: var(--accent-dim); }
.si-icon { font-size: 18px; color: var(--accent); width: 18px; text-align: center; }
.si-body { display: flex; flex-direction: column; line-height: 1.25; overflow: hidden; }
.si-name { font-size: 12px; color: var(--text); font-weight: 600; }
.si-meta { font-size: 10px; color: var(--text3); }

.structure-actions { display: flex; gap: 5px; }
.btn-mini {
  flex: 1;
  background: var(--bg3);
  border: 1px solid var(--border);
  color: var(--text2);
  font-size: 11px;
  padding: 6px 4px;
  border-radius: var(--radius);
  cursor: pointer;
  transition: border-color .15s, color .15s;
}
.btn-mini:hover { border-color: var(--accent); color: var(--accent); }
.btn-mini.danger:hover { border-color: var(--red); color: var(--red); }
.hint { font-size: 10px; color: var(--text3); margin-top: 8px; line-height: 1.45; }

/* ── Land scan upload ─────────────────────────────────────────────────────── */
.file-drop {
  display: flex; align-items: center; gap: 8px;
  width: 100%;
  background: var(--bg3);
  border: 1px dashed var(--border);
  color: var(--text2);
  font-size: 11px;
  padding: 12px 10px;
  border-radius: var(--radius);
  cursor: pointer;
  transition: border-color .15s, color .15s, background .15s;
}
.file-drop:hover, .file-drop.dragover { border-color: var(--accent); color: var(--accent); background: var(--accent-dim); }
.file-drop.loaded { border-style: solid; border-color: var(--accent); color: var(--accent); }
.file-drop .fd-icon { font-size: 16px; }
.seg { display: flex; gap: 4px; }
.seg-btn {
  flex: 1;
  background: var(--bg3);
  border: 1px solid var(--border);
  color: var(--text2);
  font-size: 11px;
  padding: 5px 4px;
  border-radius: var(--radius);
  cursor: pointer;
  transition: border-color .15s, color .15s, background .15s;
}
.seg-btn:hover { border-color: var(--accent); color: var(--text); }
.seg-btn.active { border-color: var(--accent); background: var(--accent-dim); color: var(--accent); }
.land-info {
  font-size: 10.5px; color: var(--text2);
  background: var(--accent-dim);
  border: 1px solid rgba(74,222,128,.3);
  border-radius: 6px;
  padding: 6px 8px; margin-top: 8px; line-height: 1.5;
}
.warn-text { color: var(--amber); }
#opening-warnings { margin-top: 6px; }
.warning {
  font-size: 10.5px;
  color: var(--amber);
  background: rgba(251,191,36,.08);
  border: 1px solid rgba(251,191,36,.3);
  border-radius: 6px;
  padding: 5px 8px;
  margin-top: 5px;
  line-height: 1.4;
}
.chk-row { display: flex; align-items: center; gap: 7px; cursor: pointer; color: var(--text2); }
.chk-row input { accent-color: var(--accent); width: 14px; height: 14px; }
.muted { color: var(--text3); font-weight: 400; text-transform: none; letter-spacing: 0; }

/* Selected-structure mini stats */
.mini-stats { display: flex; flex-direction: column; gap: 3px; }
.ms-row { display: flex; justify-content: space-between; font-size: 12px; padding: 3px 0; border-bottom: 1px solid rgba(42,51,71,.5); }
.ms-k { color: var(--text3); }
.ms-v { color: var(--text); font-weight: 600; text-transform: capitalize; }

/* ── Structure type radio cards ── */
.radio-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 6px;
}
.radio-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  padding: 10px 4px;
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  font-size: 11px;
  color: var(--text2);
  transition: border-color .2s, color .2s, background .2s;
  user-select: none;
}
.radio-card .rc-icon { font-size: 18px; }
.radio-card:hover { border-color: var(--accent); color: var(--text); }
.radio-card.active { border-color: var(--accent); background: var(--accent-dim); color: var(--accent); }

/* ── Sliders ── */
.control-row {
  margin-bottom: 10px;
}
.control-row label {
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--text2);
  margin-bottom: 4px;
  font-size: 12px;
}
.unit { color: var(--text3); font-size: 11px; }

.slider-row {
  display: flex;
  align-items: center;
  gap: 8px;
}
input[type="range"] {
  flex: 1;
  height: 3px;
  -webkit-appearance: none;
  appearance: none;
  background: var(--bg3);
  border-radius: 2px;
  outline: none;
}
input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 14px;
  height: 14px;
  background: var(--accent);
  border-radius: 50%;
  cursor: pointer;
}
input[type="range"]::-moz-range-thumb {
  width: 14px;
  height: 14px;
  background: var(--accent);
  border-radius: 50%;
  border: none;
  cursor: pointer;
}

.num-input {
  width: 52px;
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: 5px;
  color: var(--text);
  font-size: 12px;
  padding: 3px 6px;
  text-align: right;
}
.num-input:focus { outline: none; border-color: var(--accent); }

/* ── Radio list (fill material) ── */
.radio-list { display: flex; flex-direction: column; gap: 4px; }
.rl-item {
  padding: 7px 10px;
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  font-size: 12px;
  color: var(--text2);
  transition: border-color .2s, color .2s;
  display: flex;
  align-items: center;
  gap: 6px;
  user-select: none;
}
.rl-item:hover { border-color: var(--accent); }
.rl-item.active { border-color: var(--accent); color: var(--text); background: var(--accent-dim); }
.badge { font-size: 9px; padding: 1px 5px; border-radius: 4px; font-weight: 700; letter-spacing: .5px; }
.badge.eco { background: rgba(74,222,128,.2); color: var(--accent); }

/* ── Stepper ── */
.stepper {
  display: flex;
  align-items: center;
  gap: 0;
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  width: fit-content;
}
.step-btn {
  background: transparent;
  border: none;
  color: var(--text2);
  width: 28px;
  height: 28px;
  cursor: pointer;
  font-size: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background .15s;
}
.step-btn:hover { background: var(--accent-dim); color: var(--accent); }
.step-val {
  min-width: 28px;
  text-align: center;
  font-size: 13px;
  font-weight: 600;
  color: var(--text);
}

/* ── Select ── */
.sel-input {
  width: 100%;
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text);
  font-size: 12px;
  padding: 6px 10px;
}
.sel-input:focus { outline: none; border-color: var(--accent); }

/* ── Viewport ── */
#viewport-container {
  position: relative;
  background: var(--bg);
  overflow: hidden;
}
#three-canvas { display: block; width: 100%; height: 100%; }

/* ── Position gizmo ── */
#pos-gizmo {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;   /* pass-through everywhere except the arrow hit areas */
  overflow: visible;
  z-index: 2;
}
/* Hide gizmo outside Layout mode */
body.level-2 #pos-gizmo,
body.level-3 #pos-gizmo { display: none !important; }

/* View controls */
#view-controls {
  position: absolute;
  top: 12px;
  left: 12px;
  display: flex;
  gap: 4px;
}
.view-btn {
  background: rgba(22,27,36,.85);
  border: 1px solid var(--border);
  color: var(--text2);
  padding: 5px 9px;
  border-radius: var(--radius);
  cursor: pointer;
  font-size: 10px;
  font-weight: 600;
  letter-spacing: .5px;
  transition: all .2s;
  backdrop-filter: blur(4px);
  white-space: nowrap;
}
.view-btn:hover { border-color: var(--accent); color: var(--accent); }
.view-btn.active { background: var(--accent-dim); border-color: var(--accent); color: var(--accent); }

/* Layer controls */
#layer-controls {
  position: absolute;
  top: 12px;
  right: 12px;
  display: flex;
  align-items: center;
  gap: 6px;
  background: rgba(22,27,36,.85);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 6px 10px;
  backdrop-filter: blur(4px);
}
.layer-label { font-size: 10px; color: var(--text3); font-weight: 700; letter-spacing: .8px; text-transform: uppercase; margin-right: 2px; }
.layer-toggle { display: flex; align-items: center; cursor: pointer; }
.layer-toggle input { display: none; }
.toggle-chip {
  font-size: 11px;
  padding: 3px 9px;
  border-radius: 20px;
  border: 1px solid transparent;
  cursor: pointer;
  font-weight: 600;
  transition: all .2s;
  opacity: 0.4;
}
.layer-toggle input:checked + .toggle-chip { opacity: 1; }
.toggle-chip.earthbag { border-color: #a16207; color: #fbbf24; background: rgba(251,191,36,.1); }
.toggle-chip.wire { border-color: #b45309; color: var(--wire-col); background: rgba(200,168,75,.1); }
.toggle-chip.plaster { border-color: #475569; color: #94a3b8; background: rgba(148,163,184,.1); }
.toggle-chip.terrain { border-color: #166534; color: var(--accent); background: rgba(74,222,128,.1); }

/* Course nav */
#course-nav {
  position: absolute;
  bottom: 36px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  align-items: center;
  gap: 6px;
  background: rgba(22,27,36,.88);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 5px 12px;
  backdrop-filter: blur(4px);
}
.cn-label { font-size: 10px; color: var(--text3); text-transform: uppercase; letter-spacing: .8px; }
.cn-btn {
  font-size: 11px;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 12px;
  color: var(--text2);
  padding: 3px 10px;
  cursor: pointer;
  transition: all .2s;
}
.cn-btn.active { background: var(--accent-dim); border-color: var(--accent); color: var(--accent); }
#cn-step-controls { display: flex; align-items: center; gap: 6px; }
#cn-step-controls button {
  background: transparent;
  border: none;
  color: var(--text2);
  font-size: 16px;
  cursor: pointer;
  padding: 0 4px;
}
#cn-step-controls button:hover { color: var(--accent); }
#cn-current { min-width: 24px; text-align: center; font-size: 12px; font-weight: 600; color: var(--text); }

/* Status bar */
#status-bar {
  position: absolute;
  bottom: 8px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 16px;
  font-size: 10px;
  color: var(--text3);
}

/* ── Right panel stats ── */
.stat-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}
.stat-card {
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 10px;
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.stat-val {
  font-size: 22px;
  font-weight: 700;
  color: var(--accent);
  line-height: 1;
}
.stat-label {
  font-size: 10px;
  color: var(--text3);
  text-transform: uppercase;
  letter-spacing: .5px;
}

/* ── Detail table ── */
.detail-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 12px;
}
.detail-table th {
  text-align: left;
  color: var(--text3);
  font-size: 10px;
  letter-spacing: .5px;
  text-transform: uppercase;
  padding: 4px 0;
  border-bottom: 1px solid var(--border);
}
.detail-table td {
  padding: 5px 0;
  border-bottom: 1px solid rgba(42,51,71,.5);
  color: var(--text2);
}
.detail-table td:last-child { text-align: right; color: var(--text3); font-size: 11px; }
.detail-table td:nth-child(2) { text-align: right; color: var(--text); font-weight: 600; }

/* ── Time breakdown ── */
.time-breakdown { display: flex; flex-direction: column; gap: 6px; }
.tb-row {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 12px;
}
.tb-label { flex: 1; color: var(--text2); }
.tb-bar-wrap { flex: 2; height: 6px; background: var(--bg3); border-radius: 3px; overflow: hidden; }
.tb-bar { height: 100%; border-radius: 3px; background: var(--accent); }
.tb-val { width: 48px; text-align: right; color: var(--text); font-weight: 600; font-size: 11px; }

/* ── Small inline action button ── */
.mini-btn {
  font-size: 10px; padding: 3px 8px; margin-top: 6px;
  border-radius: 5px; border: 1px solid var(--border);
  background: var(--bg3); color: var(--text2); cursor: pointer;
}
.mini-btn:hover { color: var(--accent); border-color: var(--accent); }

/* ── Geometric coherency F bar ── */
.fbar-row { display: flex; align-items: center; gap: 8px; }
.fbar-wrap { flex: 1; height: 8px; background: var(--bg3); border-radius: 4px; overflow: hidden; }
.fbar { height: 100%; border-radius: 4px; background: var(--accent); transition: width .3s ease, background .3s ease; }
.fbar.warn { background: var(--amber); }
.fbar.fail { background: var(--red); }
.fbar-val { width: 58px; text-align: right; font-weight: 700; font-size: 13px; color: var(--text); }
.fbar-val.warn { color: var(--amber); }
.fbar-val.fail { color: var(--red); }

/* ── Eco score ── */
.eco-bar-wrap {
  height: 8px;
  background: var(--bg3);
  border-radius: 4px;
  overflow: hidden;
  margin-bottom: 6px;
}
.eco-bar {
  height: 100%;
  border-radius: 4px;
  background: linear-gradient(90deg, var(--amber), var(--accent));
  transition: width .5s ease;
}
#eco-score-val { font-size: 20px; font-weight: 700; color: var(--accent); }
.eco-desc { font-size: 11px; color: var(--text3); margin-top: 4px; line-height: 1.5; }

/* ── Layer plan canvas ── */
#layer-plan-container {
  background: var(--bg3);
  border-radius: var(--radius);
  overflow: hidden;
  display: flex;
  justify-content: center;
}
#layer-plan-canvas { display: block; max-width: 100%; }

/* ── Simulation: viewport field selector ── */
#sim-fields {
  position: absolute;
  top: 12px;
  right: 12px;
  display: flex;
  align-items: center;
  gap: 4px;
  background: rgba(22,27,36,.85);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 6px 8px;
  backdrop-filter: blur(4px);
}
.sim-field-btn {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text2);
  padding: 4px 8px;
  border-radius: 12px;
  cursor: pointer;
  font-size: 10px;
  font-weight: 600;
  transition: all .2s;
  white-space: nowrap;
}
.sim-field-btn:hover { border-color: var(--accent); color: var(--text); }
.sim-field-btn.active { background: var(--accent-dim); border-color: var(--accent); color: var(--accent); }

/* ── Simulation: colour legend ── */
#sim-legend {
  position: absolute;
  bottom: 60px;
  right: 12px;
  width: 150px;
  background: rgba(22,27,36,.85);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 8px 10px;
  backdrop-filter: blur(4px);
}
#sim-legend-title { font-size: 10px; color: var(--text2); font-weight: 700; text-transform: uppercase; letter-spacing: .5px; }
#sim-legend-bar {
  height: 9px;
  border-radius: 3px;
  margin: 6px 0 3px;
  background: linear-gradient(90deg, #4ade80, #facc15, #ef4444);
}
#sim-legend-bar.diverging {
  background: linear-gradient(90deg, #3b82f6, #8b98a8, #ef4444);
}
#sim-legend-scale { display: flex; justify-content: space-between; font-size: 9px; color: var(--text3); }

/* ── Simulation: results ── */
.sim-verdict {
  font-size: 12.5px;
  font-weight: 700;
  line-height: 1.4;
  padding: 9px 11px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  margin-bottom: 10px;
}
.sim-verdict.ok   { color: var(--accent); background: rgba(74,222,128,.10); border-color: rgba(74,222,128,.4); }
.sim-verdict.warn { color: var(--amber);  background: rgba(251,191,36,.08); border-color: rgba(251,191,36,.4); }
.sim-verdict.fail { color: var(--red);    background: rgba(248,113,113,.10); border-color: rgba(248,113,113,.45); }

.sim-util-bar-wrap { height: 8px; background: var(--bg3); border-radius: 4px; overflow: hidden; margin-bottom: 6px; }
.sim-util-bar { height: 100%; border-radius: 4px; background: linear-gradient(90deg, var(--accent), var(--amber), var(--red)); transition: width .4s ease; }
.sim-util-row { display: flex; justify-content: space-between; font-size: 12px; padding: 2px 0; color: var(--text2); }
.sim-util-row span:last-child { color: var(--text); font-weight: 600; }

/* Global stability check rows */
.sim-check {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 0;
  border-bottom: 1px solid rgba(42,51,71,.5);
  font-size: 12px;
}
.sim-check-icon { width: 16px; text-align: center; font-weight: 700; }
.sim-check.pass .sim-check-icon { color: var(--accent); }
.sim-check.fail .sim-check-icon { color: var(--red); }
.sim-check-name { flex: 1; color: var(--text2); }
.sim-check-val { color: var(--text); font-weight: 600; font-size: 11px; }
.sim-check-bar-wrap { width: 46px; height: 5px; background: var(--bg3); border-radius: 3px; overflow: hidden; }
.sim-check-bar { height: 100%; }

/* ── Scrollbar for panel sections ── */
::-webkit-scrollbar { width: 4px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 2px; }