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

:root {
  --bg:        #0b111a;
  --surface:   #111927;
  --surface2:  #162032;
  --border:    #1f3050;
  --accent:    #00c4aa;
  --accent2:   #3d8bff;
  --lp-color:  #e8a020;
  --bif-color: #3dba5a;
  --aif-color: #2d88d4;
  --ht-color:  #a030d8;
  --text:      #d8e4f0;
  --muted:     #6a8aaa;
  --danger:    #ff5f5f;
}

html, body {
  height: 100%;
  font-family: 'Segoe UI', system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  font-size: 14px;
  line-height: 1.5;
}

/* ── Layout ────────────────────────────────────────────────────────────────── */
body { display: flex; flex-direction: column; height: 100vh; overflow: hidden; }

header {
  padding: 14px 24px;
  background: linear-gradient(135deg, #0d1e35 0%, #0b111a 100%);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: 16px;
  flex-shrink: 0;
}

.btn-back {
  margin-left: auto;
  padding: 7px 18px;
  background: rgb(42, 90, 140);
  border: 1px solid rgb(74, 138, 191);
  border-radius: 4px;
  color: rgb(232, 244, 255);
  text-decoration: none;
  font-size: 13.6px;
  font-weight: 600;
  white-space: nowrap;
  cursor: pointer;
  transition: background .15s, border-color .15s;
}
.btn-back:hover { background: rgb(55, 115, 175); border-color: rgb(100, 165, 220); }

header h1 {
  font-size: 1.2rem;
  font-weight: 700;
  letter-spacing: .04em;
  color: var(--accent);
  text-transform: uppercase;
}

header p { color: var(--muted); font-size: .85rem; }

.controls-bar {
  display: flex;
  gap: 16px;
  align-items: center;
  padding: 10px 24px;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
  flex-wrap: wrap;
}

.control-group {
  display: flex;
  align-items: center;
  gap: 8px;
}

.control-group label {
  font-size: .8rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: .06em;
  white-space: nowrap;
}

select {
  background: var(--surface2);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 6px 32px 6px 10px;
  font-size: .9rem;
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8'%3E%3Cpath d='M0 0l6 8 6-8z' fill='%236a8aaa'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 10px center;
  transition: border-color .15s;
}
select:focus { outline: none; border-color: var(--accent); }

/* ── Main content ───────────────────────────────────────────────────────────── */
main {
  display: flex;
  flex: 1;
  overflow: hidden;
}

/* ── Sidebar ────────────────────────────────────────────────────────────────── */
.sidebar {
  width: 240px;
  min-width: 200px;
  background: var(--surface);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  flex-shrink: 0;
}

.sidebar-header {
  padding: 10px 14px;
  font-size: .75rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: .08em;
  border-bottom: 1px solid var(--border);
}

#product-list {
  flex: 1;
  overflow-y: auto;
  padding: 6px 0;
  scrollbar-width: thin;
  scrollbar-color: var(--border) transparent;
}

.product-btn {
  width: 100%;
  text-align: left;
  background: none;
  border: none;
  padding: 8px 14px;
  color: var(--text);
  cursor: pointer;
  font-size: .88rem;
  border-left: 3px solid transparent;
  transition: background .1s, border-color .1s;
  line-height: 1.3;
}
.product-btn:hover  { background: var(--surface2); border-left-color: var(--border); }
.product-btn.active { background: var(--surface2); border-left-color: var(--accent); color: var(--accent); }

/* ── Content area ───────────────────────────────────────────────────────────── */
.content {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

/* Placeholder */
#placeholder {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
  color: var(--muted);
}

.placeholder-icon { font-size: 3rem; opacity: .4; }
.placeholder-text { font-size: 1rem; }
.placeholder-sub  { font-size: .8rem; opacity: .6; }

/* Preview panel */
#preview-panel {
  display: none;
  flex-direction: column;
  flex: 1;
  overflow: hidden;
}

/* ── Preview top: SVG + stats ───────────────────────────────────────────────── */
.preview-top {
  display: flex;
  gap: 0;
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
  height: 280px;
}

.svg-wrap {
  flex: 1;
  background: #0d1520;
  border-right: 1px solid var(--border);
  overflow: hidden;
}

#layout-svg {
  width: 100%;
  height: 100%;
  display: block;
}

.stats-panel {
  width: 280px;
  flex-shrink: 0;
  padding: 18px 20px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.stat-block { display: flex; flex-direction: column; gap: 6px; }

.stat-label {
  font-size: .72rem;
  text-transform: uppercase;
  letter-spacing: .08em;
  color: var(--muted);
}

.stat-value { font-size: 1rem; font-weight: 600; }
.stat-value.large { font-size: 1.6rem; color: var(--accent); }

.bar-bg {
  height: 6px;
  background: var(--border);
  border-radius: 3px;
  overflow: hidden;
}
.bar-fill {
  height: 100%;
  border-radius: 3px;
  transition: width .3s ease;
}
.bar-fill.cpu   { background: var(--accent2); }
.bar-fill.power { background: var(--lp-color); }

/* Schematic display */
.inputs-block {
  padding: 10px 20px;
  border-bottom: 1px solid var(--border);
  background: var(--surface2);
  flex-shrink: 0;
}
.inputs-label {
  font-size: .7rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: .08em;
  margin-bottom: 6px;
}
#inputs-display { display: flex; flex-wrap: wrap; gap: 6px; align-items: center; }

.input-tag {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 2px 8px;
  font-size: .8rem;
  color: var(--aif-color);
}
.output-tag {
  background: var(--surface);
  border: 1px solid var(--accent);
  border-radius: 4px;
  padding: 2px 8px;
  font-size: .8rem;
  color: var(--accent);
  font-weight: 600;
}
.arrow { color: var(--muted); font-size: 1.1rem; }

/* ── JSON section ───────────────────────────────────────────────────────────── */
.json-section {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.json-toolbar {
  display: flex;
  gap: 10px;
  align-items: center;
  padding: 8px 16px;
  background: var(--surface2);
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}

.json-title {
  font-size: .75rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: .08em;
  flex: 1;
}

.btn {
  padding: 5px 14px;
  border-radius: 5px;
  border: 1px solid;
  font-size: .82rem;
  font-weight: 600;
  cursor: pointer;
  text-decoration: none;
  transition: background .15s, transform .1s;
  display: inline-flex;
  align-items: center;
  gap: 5px;
}
.btn:active { transform: scale(.97); }

.btn-copy {
  background: var(--surface);
  border-color: var(--accent);
  color: var(--accent);
}
.btn-copy:hover  { background: var(--accent); color: #000; }
.btn-copy.copied { background: var(--accent); color: #000; }

.btn-download {
  background: var(--surface);
  border-color: var(--accent2);
  color: var(--accent2);
}
.btn-download:hover { background: var(--accent2); color: #fff; }

.json-scroll {
  flex: 1;
  overflow: auto;
  padding: 14px 18px;
  scrollbar-width: thin;
  scrollbar-color: var(--border) transparent;
}

#json-output {
  display: block;
  font-family: 'Cascadia Code', 'Fira Code', 'Consolas', monospace;
  font-size: .78rem;
  line-height: 1.6;
  color: #a8c8e8;
  white-space: pre;
  tab-size: 2;
}

/* ── Tier colour accents ────────────────────────────────────────────────────── */
body[data-tier="P1"] .product-btn.active { border-left-color: var(--bif-color); color: var(--bif-color); }
body[data-tier="P2"] .product-btn.active,
body[data-tier="P3"] .product-btn.active { border-left-color: var(--aif-color); color: var(--aif-color); }
body[data-tier="P4"] .product-btn.active { border-left-color: var(--ht-color);  color: var(--ht-color); }

/* ── Scrollbars ─────────────────────────────────────────────────────────────── */
::-webkit-scrollbar       { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }

/* ── Responsive: stack vertically on narrow screens ─────────────────────────── */
@media (max-width: 780px) {
  body { overflow-y: auto; }
  main { flex-direction: column; overflow: visible; }
  .sidebar { width: 100%; min-width: unset; border-right: none; border-bottom: 1px solid var(--border); max-height: 220px; }
  .preview-top { flex-direction: column; height: auto; }
  .svg-wrap { height: 240px; border-right: none; border-bottom: 1px solid var(--border); }
  .stats-panel { width: 100%; }
  #preview-panel { overflow: visible; }
  .content { overflow: visible; }
  .json-section { min-height: 300px; }
}