:root {
  --bg: #000000;
  --panel: #0a0a0a;
  --panel-2: #0f0f10;
  --ink: #f4f7fb;
  --muted: #8b9098;
  --line: rgba(255,255,255,0.09);
  --line-strong: rgba(255,255,255,0.18);
  --accent: #59a6ff;
  --success: #4cffba;
  --warning: #ffd34d;
  --danger: #ff5f43;
  --radius: 14px;
  --shadow: 0 18px 60px rgba(0,0,0,0.45);
  --mono: 'IBM Plex Mono','SFMono-Regular',Consolas,monospace;
  --sans: Inter, ui-sans-serif, system-ui, -apple-system, sans-serif;
  color-scheme: dark;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; background: var(--bg); color: var(--ink); font-family: var(--sans); min-height: 100%; -webkit-font-smoothing: antialiased; }
body { background: radial-gradient(circle at top, rgba(89,166,255,0.08), transparent 32%), var(--bg); min-height: 100vh; }
button, input, select, textarea { font: inherit; color: inherit; }
button { cursor: pointer; }
a { color: inherit; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

/* ====== Layout shell ====== */
.app-shell {
  display: grid;
  grid-template-columns: 264px minmax(0, 1fr);
  min-height: 100vh;
}
.sidebar {
  border-right: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(255,255,255,0.02), rgba(255,255,255,0));
  padding: 20px 18px;
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
}
.main {
  padding: 22px;
  padding-bottom: 80px;
  min-width: 0;
  overflow-x: hidden;
}
.topbar {
  position: sticky;
  top: 0;
  z-index: 5;
  background: rgba(0,0,0,0.72);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 8px 0 14px;
  margin-bottom: 14px;
  border-bottom: 1px solid var(--line);
}
.topbar h2 { margin: 0; font-size: 18px; letter-spacing: 0.06em; }
.topbar .subtitle { display: block; font-family: var(--mono); font-size: 11px; color: var(--muted); margin-top: 2px; letter-spacing: 0.08em; }
.topbar-actions { display: flex; gap: 8px; flex-wrap: wrap; }

.menu-toggle, .menu-close { display: none; }

/* ====== Sidebar ====== */
.brand { display: flex; justify-content: space-between; align-items: center; margin-bottom: 14px; }
.brand h1 { margin: 0; font-size: 15px; line-height: 1.15; letter-spacing: 0.1em; }
.brand small { display: block; color: var(--muted); font-family: var(--mono); font-size: 10px; letter-spacing: 0.14em; margin-top: 4px; }
.brand-home { display: block; text-decoration: none; color: inherit; border-radius: 8px; transition: opacity 120ms ease; }
.brand-home:hover { opacity: 0.82; }
.brand-home:hover h1 { color: var(--accent); }
.pill { font-family: var(--mono); font-size: 10px; padding: 4px 8px; border: 1px solid var(--line-strong); border-radius: 999px; color: var(--muted); }

/* Sidebar "back to home" affordance — unobtrusive, matches nav buttons. */
.home-link {
  display: flex;
  align-items: center;
  justify-content: center;
  text-decoration: none;
  border: 1px solid var(--line);
  background: var(--panel);
  color: var(--muted);
  border-radius: 12px;
  padding: 9px 12px;
  margin-bottom: 4px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  min-height: 38px;
  transition: border-color 120ms ease, background 120ms ease, color 120ms ease;
}
.home-link:hover { border-color: rgba(89,166,255,0.5); color: var(--ink); background: var(--panel-2); }

/* Topbar "back to home" affordance — always visible, even when the
   sidebar is collapsed behind the hamburger on mobile. */
.home-link-top { text-decoration: none; flex-shrink: 0; color: var(--muted); }
.home-link-top:hover { border-color: rgba(89,166,255,0.5); color: var(--ink); }

.section-title {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.18em;
  color: var(--muted);
  margin: 14px 0 8px;
}

.mode-grid, .nav-list { display: grid; gap: 6px; }
.mode-btn, .nav-btn {
  display: grid;
  text-align: left;
  border: 1px solid var(--line);
  background: var(--panel);
  border-radius: 12px;
  padding: 10px 12px;
  transition: border-color 120ms ease, background 120ms ease;
}
.mode-btn { box-shadow: inset 2px 0 0 var(--mode-color, var(--line-strong)); }
.mode-btn strong, .nav-btn strong { font-family: var(--mono); font-size: 11px; letter-spacing: 0.1em; }
.mode-btn span, .nav-btn span { color: var(--muted); font-family: var(--mono); font-size: 10px; margin-top: 4px; letter-spacing: 0.06em; }
.mode-btn.active, .nav-btn.active {
  background: linear-gradient(180deg, rgba(255,255,255,0.06), rgba(255,255,255,0.02));
  border-color: rgba(255,255,255,0.22);
}
.mode-btn:hover, .nav-btn:hover { border-color: var(--line-strong); }

.sidebar-footer { margin-top: 22px; padding-top: 14px; border-top: 1px solid var(--line); color: var(--muted); font-family: var(--mono); font-size: 10px; line-height: 1.5; letter-spacing: 0.04em; }

/* ====== Buttons ====== */
.primary-btn, .ghost-btn, .danger-btn, .icon-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  border: 1px solid var(--line);
  background: var(--panel);
  color: var(--ink);
  border-radius: 12px;
  padding: 9px 12px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  transition: border-color 120ms ease, background 120ms ease;
  min-height: 38px;
}
.primary-btn { background: linear-gradient(180deg, rgba(89,166,255,0.18), rgba(89,166,255,0.08)); border-color: rgba(89,166,255,0.4); }
.primary-btn:hover { border-color: rgba(89,166,255,0.6); }
.ghost-btn:hover { border-color: var(--line-strong); background: var(--panel-2); }
.danger-btn { background: linear-gradient(180deg, rgba(255,95,67,0.18), rgba(255,95,67,0.08)); border-color: rgba(255,95,67,0.35); }
.danger-btn:hover { border-color: rgba(255,95,67,0.55); }
.icon-btn { padding: 8px 10px; }

.button-row { display: flex; flex-wrap: wrap; gap: 8px; }

/* ====== Panels and cards ====== */
.panel, .card, .metric, .segment, .chat-bubble, .diff-cell {
  background: linear-gradient(180deg, rgba(255,255,255,0.025), rgba(255,255,255,0.01));
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}
.panel { padding: 16px; }
.panel-head { display: flex; justify-content: space-between; gap: 10px; flex-wrap: wrap; align-items: flex-start; margin-bottom: 12px; }
.panel-head h3 { margin: 0; font-size: 13px; letter-spacing: 0.12em; }
.panel-head p { margin: 4px 0 0; color: var(--muted); font-family: var(--mono); font-size: 11px; }

.layout-grid { display: grid; gap: 14px; }
.layout-2 { grid-template-columns: 360px minmax(0, 1fr); }
.layout-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }

/* ====== Form controls ====== */
.field { display: grid; gap: 6px; }
.field label, .small-label {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.14em;
  color: var(--muted);
}
input, select, textarea {
  width: 100%;
  background: rgba(255,255,255,0.025);
  border: 1px solid var(--line);
  border-radius: 10px;
  color: var(--ink);
  padding: 10px 12px;
  outline: none;
  transition: border-color 120ms ease, box-shadow 120ms ease;
  min-height: 40px;
}
textarea { min-height: 96px; resize: vertical; }
input:focus, select:focus, textarea:focus {
  border-color: rgba(89,166,255,0.45);
  box-shadow: 0 0 0 1px rgba(89,166,255,0.25);
}

.form-grid { display: grid; gap: 12px; }
.form-grid.two-col { grid-template-columns: repeat(2, minmax(0, 1fr)); }

/* ====== Stage cards ====== */
.stage-grid { display: grid; gap: 12px; grid-template-columns: repeat(2, minmax(0, 1fr)); }
.card { padding: 14px; }
.card-head { display: flex; justify-content: space-between; align-items: flex-start; gap: 10px; margin-bottom: 10px; }
.card-head h4 { margin: 0; font-family: var(--mono); font-size: 12px; letter-spacing: 0.14em; }
.card-head .badge-stack { display: flex; gap: 6px; flex-wrap: wrap; }
.card-foot { display: flex; justify-content: space-between; gap: 8px; margin-top: 12px; flex-wrap: wrap; }
.card-note { color: var(--muted); font-family: var(--mono); font-size: 11px; margin: 0 0 10px; }

.kv-list { display: grid; gap: 6px; }
.kv-row { display: grid; grid-template-columns: 116px minmax(0,1fr) auto; gap: 10px; align-items: start; }
.kv-row .kv-label { font-family: var(--mono); font-size: 10px; color: var(--muted); text-transform: uppercase; letter-spacing: 0.14em; padding-top: 4px; }
.kv-row .kv-value { font-family: var(--mono); font-size: 12px; line-height: 1.5; word-break: break-word; }

.confidence {
  font-family: var(--mono);
  font-size: 10px;
  padding: 3px 8px;
  border-radius: 999px;
  border: 1px solid var(--line-strong);
  color: var(--muted);
  letter-spacing: 0.1em;
}

.badge {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.12em;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  padding: 4px 8px;
  background: rgba(255,255,255,0.02);
  color: var(--muted);
}
.badge.success { color: var(--success); border-color: rgba(76,255,186,0.45); }
.badge.warning { color: var(--warning); border-color: rgba(255,211,77,0.45); }
.badge.danger { color: var(--danger); border-color: rgba(255,95,67,0.45); }
.badge.muted { color: var(--muted); }

.stage-card.locked { border-color: rgba(76,255,186,0.45); }
.stage-card.proposed { border-color: rgba(255,211,77,0.45); }

.chip-row { display: flex; flex-wrap: wrap; gap: 6px; }
.chip { font-family: var(--mono); font-size: 11px; padding: 4px 9px; border: 1px solid var(--line-strong); border-radius: 999px; background: rgba(255,255,255,0.02); }

/* ====== Library/table ====== */
.library-toolbar { display: grid; grid-template-columns: 1fr repeat(3, 150px) auto; gap: 8px; margin-bottom: 12px; }
.library-list { display: grid; gap: 8px; }
.library-row {
  display: grid;
  grid-template-columns: minmax(0,2fr) 110px 130px 110px auto;
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: rgba(255,255,255,0.015);
}
.library-row h4 { margin: 0; font-size: 13px; font-family: var(--mono); letter-spacing: 0.06em; }
.library-row p { margin: 2px 0 0; color: var(--muted); font-family: var(--mono); font-size: 11px; }
.library-row .row-actions { display: flex; gap: 6px; flex-wrap: wrap; justify-content: flex-end; }

.diff-grid { display: grid; grid-template-columns: repeat(2, minmax(0,1fr)); gap: 10px; }
.diff-cell { padding: 12px; }
.diff-cell pre { font-family: var(--mono); font-size: 11px; margin: 0; white-space: pre-wrap; word-break: break-word; line-height: 1.5; }
.diff-cell pre.diff-changed { color: var(--warning); }

/* ====== Chat ====== */
.chat-layout { display: grid; grid-template-columns: minmax(0,1.1fr) minmax(0,0.9fr); gap: 14px; }
.chat-log { display: grid; gap: 10px; max-height: 480px; overflow-y: auto; padding-right: 4px; }
.chat-bubble { padding: 12px 14px; }
.chat-bubble.user { border-color: rgba(89,166,255,0.4); }
.chat-bubble .meta { font-family: var(--mono); font-size: 10px; color: var(--muted); letter-spacing: 0.16em; margin-bottom: 6px; }
.chat-bubble p { margin: 0; font-family: var(--mono); font-size: 12px; line-height: 1.6; white-space: pre-wrap; }

.stage-strip { display: grid; gap: 10px; }
.stage-mini { border: 1px solid var(--line); border-radius: 12px; padding: 12px; background: rgba(255,255,255,0.015); }
.stage-mini.locked { border-color: rgba(76,255,186,0.5); }
.stage-mini.proposed { border-color: rgba(255,211,77,0.5); }

/* ====== Canvas ====== */
.canvas-grid { display: grid; gap: 12px; grid-template-columns: repeat(3, minmax(0,1fr)); }
.canvas-wrap { background: #050505; border: 1px solid var(--line); border-radius: 12px; padding: 10px; }
.canvas-wrap canvas { display: block; width: 100%; height: 180px; }

/* ====== File drop ====== */
.dropzone {
  border: 1px dashed var(--line-strong);
  border-radius: 14px;
  padding: 20px;
  text-align: center;
  background: rgba(255,255,255,0.015);
}
.dropzone.dragging { border-color: rgba(89,166,255,0.6); background: rgba(89,166,255,0.07); }
.dropzone label { font-family: var(--mono); font-size: 11px; letter-spacing: 0.1em; cursor: pointer; }

/* ====== Toast ====== */
.toast-root { position: fixed; bottom: 22px; right: 22px; left: 22px; display: flex; flex-direction: column; gap: 8px; pointer-events: none; z-index: 1000; align-items: flex-end; }
.toast {
  background: rgba(15,15,20,0.95);
  border: 1px solid var(--line-strong);
  border-radius: 12px;
  padding: 10px 14px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--ink);
  pointer-events: auto;
  transform: translateY(8px);
  opacity: 0;
  transition: transform 180ms ease, opacity 180ms ease;
  max-width: 90vw;
}
.toast-in { transform: translateY(0); opacity: 1; }
.toast-out { transform: translateY(8px); opacity: 0; }
.toast-success { border-color: rgba(76,255,186,0.45); }
.toast-error { border-color: rgba(255,95,67,0.55); }
.toast-info { border-color: rgba(89,166,255,0.45); }

/* ====== Modal ====== */
.modal-overlay {
  position: fixed; inset: 0;
  background: rgba(0,0,0,0.65);
  display: flex; align-items: center; justify-content: center;
  z-index: 900; opacity: 0; transition: opacity 180ms ease;
  padding: 18px;
}
.modal-overlay.modal-open { opacity: 1; }
.modal-overlay.modal-closing { opacity: 0; }
.modal {
  width: min(420px, 100%);
  background: var(--panel);
  border: 1px solid var(--line-strong);
  border-radius: 16px;
  padding: 18px;
  box-shadow: var(--shadow);
}
.modal-head h3 { margin: 0 0 6px; font-size: 14px; letter-spacing: 0.12em; }
.modal-body { color: var(--muted); font-family: var(--mono); font-size: 12px; margin-bottom: 14px; line-height: 1.5; }
.modal-actions { display: flex; justify-content: flex-end; gap: 8px; }

/* ====== Progress bar ====== */
.progress { height: 6px; background: rgba(255,255,255,0.06); border-radius: 999px; overflow: hidden; }
.progress > span { display: block; height: 100%; background: linear-gradient(90deg, var(--accent), var(--success)); width: 0%; transition: width 120ms ease; }

/* ====== Empty state ====== */
.empty-state {
  border: 1px dashed var(--line-strong);
  border-radius: 14px;
  padding: 18px;
  text-align: center;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.08em;
}

.empty-logo {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 18px;
  min-height: 300px;
  border-style: solid;
  border-color: var(--line);
}
.empty-logo-mark {
  width: clamp(120px, 22%, 200px);
  height: auto;
  opacity: 0.16;
  filter: drop-shadow(0 0 30px rgba(89, 166, 255, 0.12));
  user-select: none;
  -webkit-user-drag: none;
}
.empty-logo-text {
  color: var(--muted);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.08em;
}

/* ====== Helpers ====== */
.mono { font-family: var(--mono); }
.muted { color: var(--muted); }
hr { border: 0; border-top: 1px solid var(--line); margin: 14px 0; }
pre.preblock { font-family: var(--mono); font-size: 11px; line-height: 1.6; margin: 0; white-space: pre-wrap; word-break: break-word; }
.hidden { display: none !important; }
.kpi-grid { display: grid; grid-template-columns: repeat(4, minmax(0,1fr)); gap: 10px; }
.kpi {
  background: rgba(255,255,255,0.02);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 12px;
}
.kpi-label { font-family: var(--mono); font-size: 10px; letter-spacing: 0.18em; color: var(--muted); }
.kpi-value { font-family: var(--mono); font-size: 18px; margin-top: 6px; }
.kpi-sub { font-family: var(--mono); font-size: 10px; color: var(--muted); margin-top: 4px; }

.variation-grid, .breakdown-grid, .layer-grid, .macro-grid { display: grid; gap: 10px; }
.variation-grid { grid-template-columns: repeat(3, minmax(0,1fr)); }
.breakdown-grid, .layer-grid { grid-template-columns: repeat(2, minmax(0,1fr)); }
.macro-grid { grid-template-columns: repeat(2, minmax(0,1fr)); }

/* ====== Responsive ====== */
@media (max-width: 1180px) {
  .app-shell { grid-template-columns: 240px 1fr; }
  .canvas-grid { grid-template-columns: repeat(2, 1fr); }
  .library-toolbar { grid-template-columns: 1fr 1fr 1fr; }
  .library-row { grid-template-columns: minmax(0,1.5fr) auto auto auto auto; }
  .variation-grid, .breakdown-grid, .layer-grid, .macro-grid { grid-template-columns: 1fr 1fr; }
  .stage-grid { grid-template-columns: 1fr 1fr; }
  .layout-2, .layout-3 { grid-template-columns: 1fr; }
  .chat-layout { grid-template-columns: 1fr; }
}

@media (max-width: 760px) {
  .app-shell { grid-template-columns: 1fr; }
  .main { padding: 14px; padding-bottom: 90px; }
  .menu-toggle {
    display: inline-flex;
    align-items: center; justify-content: center;
    width: 38px; height: 38px;
    border: 1px solid var(--line-strong);
    background: var(--panel);
    border-radius: 10px;
  }
  .menu-close { display: inline-flex; }
  .sidebar {
    position: fixed;
    top: 0; left: 0; bottom: 0;
    width: min(82vw, 320px);
    background: #050507;
    transform: translateX(-100%);
    transition: transform 220ms ease;
    z-index: 50;
    border-right: 1px solid var(--line-strong);
    height: 100vh;
  }
  .sidebar.open { transform: translateX(0); }
  .scrim {
    position: fixed; inset: 0;
    background: rgba(0,0,0,0.6);
    z-index: 40;
    opacity: 0;
    pointer-events: none;
    transition: opacity 180ms ease;
  }
  .scrim.open { opacity: 1; pointer-events: auto; }
  .stage-grid, .canvas-grid, .variation-grid, .breakdown-grid, .layer-grid, .macro-grid,
  .kpi-grid, .library-toolbar, .diff-grid, .form-grid.two-col { grid-template-columns: 1fr; }
  .library-row { grid-template-columns: 1fr; }
  .library-row .row-actions { justify-content: flex-start; }
  .topbar h2 { font-size: 16px; }
  .panel-head { flex-direction: column; align-items: stretch; }
  .kv-row { grid-template-columns: 1fr; }
  .kv-row .kv-label { padding-top: 0; }
  .kpi-grid { grid-template-columns: 1fr 1fr; }
}