:root {
  --bg: #f7f5f0; --panel-bg: #fff; --panel-border: #e2e8f0;
  --nail-body: #b8bcc4; --nail-shadow: rgba(60,70,90,.25);
  --pole-n: #d63535; --pole-s: #2f8a3a; --field-line: rgba(60,90,140,.55);
  --text: #0f172a; --text-dim: #64748b; --accent: #534ab7;
  --accent-soft: #ede9ff; --bar-track: #e2e8f0; --bar-fill: #534ab7;
  --btn-bg: #fff; --btn-border: #cbd5e1; --btn-hover: #f5f3ff;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111418; --panel-bg: #181d24; --panel-border: #313c4b;
    --nail-body: #5d6470; --nail-shadow: rgba(0,0,0,.6);
    --pole-n: #ff5252; --pole-s: #66bb6a; --field-line: rgba(140,180,230,.55);
    --text: #eff3fb; --text-dim: #b9c6d8; --accent: #ada6ff;
    --accent-soft: #2a2955; --bar-track: #313c4b; --bar-fill: #ada6ff;
    --btn-bg: #202732; --btn-border: #3c4b5e; --btn-hover: #2a2955;
  }
}
*, *::before, *::after { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--text); font-family: Lato, sans-serif; min-height: 100dvh; padding-top: var(--sim-nav-offset, 44px); }
button { font: inherit; }
button:focus-visible, canvas:focus-visible { outline: 3px solid var(--accent); outline-offset: 2px; }
.sim-wrap { width: min(1160px, calc(100% - 32px)); margin: 20px auto 32px; display: grid; gap: 16px; }
.intro { display: grid; gap: 5px; }
.intro > * { margin: 0; }
.eyebrow { color: var(--accent); font-size: .75rem; font-weight: 800; letter-spacing: .08em; text-transform: uppercase; }
h1 { font-size: clamp(1.4rem, 3vw, 2rem); line-height: 1.2; }
.intro p:last-child { color: var(--text-dim); line-height: 1.45; }
.layout { display: grid; grid-template-columns: minmax(0, 1fr) 300px; gap: 16px; align-items: start; }
.workbench, .card { background: var(--panel-bg); border: 1px solid var(--panel-border); border-radius: 18px; box-shadow: 0 4px 12px rgba(0,0,0,.03); }
.workbench { overflow: hidden; }
.stage { overflow: hidden; }
canvas#stage { display: block; width: 100%; height: auto; touch-action: none; cursor: default; }
canvas#stage.dragging { cursor: grabbing; }
.workbench-footer { padding: 14px 18px 18px; border-top: 1px solid var(--panel-border); display: grid; gap: 12px; }
.instruction { margin: 0; font-weight: 700; line-height: 1.45; }
.instruction small { display: block; color: var(--text-dim); font-weight: 400; font-size: .84rem; margin-top: 2px; }
.controls { display: flex; flex-wrap: wrap; gap: 8px; }
.icon-btn { min-height: 44px; border: 1px solid var(--btn-border); border-radius: 10px; color: var(--text); background: var(--btn-bg); cursor: pointer; display: inline-flex; align-items: center; justify-content: center; gap: 7px; padding: 8px 11px; font-size: .85rem; font-weight: 700; transition: background .15s, border-color .15s; }
.icon-btn:hover, .choice:hover { background: var(--btn-hover); border-color: var(--accent); }
.icon-btn.active, .choice.active { background: var(--accent-soft); border-color: var(--accent); }
.icon-btn.primary { background: var(--accent); border-color: var(--accent); color: var(--panel-bg); }
.icon-btn.primary:hover { filter: brightness(1.12); }
.icon-btn:disabled { opacity: .5; cursor: not-allowed; }
.icon-btn svg { width: 18px; height: 18px; stroke: currentColor; fill: none; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; flex: none; }
.sidebar { display: grid; gap: 16px; }
.card { padding: 16px; display: grid; gap: 12px; }
.card h2, .card p { margin: 0; }
.card h2 { font-size: 1rem; }
.card p { color: var(--text-dim); line-height: 1.45; font-size: .9rem; }
.meter-heading { display: flex; justify-content: space-between; align-items: baseline; gap: 8px; }
.meter-value { font-size: 1.1rem; font-weight: 800; color: var(--accent); }
.alignment-bar-bg { height: 12px; background: var(--bar-track); border-radius: 99px; overflow: hidden; }
.alignment-bar-fill { height: 100%; width: 0%; background: var(--bar-fill); border-radius: 99px; transition: width .12s ease; }
.pole-status { font-weight: 700; color: var(--text) !important; }
.choices { display: flex; gap: 8px; }
.choice { flex: 1; min-height: 42px; border: 1px solid var(--btn-border); border-radius: 10px; color: var(--text); background: var(--btn-bg); cursor: pointer; font-weight: 700; }
.test-visual { display: flex; align-items: center; gap: 14px; padding: 9px 0; }
.compass { position: relative; width: 56px; height: 56px; flex: none; border: 2px solid var(--btn-border); border-radius: 50%; background: var(--bg); }
.compass::before, .compass::after { position: absolute; left: 50%; transform: translateX(-50%); font-size: .6rem; font-weight: 800; color: var(--text-dim); }
.compass::before { content: 'N'; top: 2px; }
.compass::after { content: 'S'; bottom: 2px; }
.needle { position: absolute; left: 50%; top: 50%; width: 9px; height: 35px; transform: translate(-50%, -50%) rotate(var(--needle-angle, 0deg)); transition: transform .6s ease; }
.needle::before, .needle::after { content: ''; position: absolute; left: 0; width: 9px; height: 18px; }
.needle::before { top: 0; background: var(--pole-n); clip-path: polygon(50% 0,100% 100%,0 100%); }
.needle::after { bottom: 0; background: var(--pole-s); clip-path: polygon(0 0,100% 0,50% 100%); }
.clips { display: flex; gap: 4px; align-items: center; flex-wrap: wrap; }
.clip { width: 15px; height: 28px; border: 3px solid var(--text-dim); border-radius: 9px; transform: rotate(20deg); opacity: .2; transition: opacity .3s, transform .3s; }
.clip.attached { opacity: 1; transform: rotate(10deg) translateY(-3px); }
.clip-count { color: var(--text-dim); font-size: .8rem; }
.test-result { min-height: 2.5em; font-weight: 700; color: var(--text) !important; }
.model-note { border-left: 3px solid var(--accent); padding-left: 10px; }
@media (max-width: 940px) { .layout { grid-template-columns: 1fr; } .sidebar { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
@media (max-width: 620px) {
  .sim-wrap { width: calc(100% - 20px); margin: 14px auto 24px; gap: 12px; }
  .layout, .sidebar { gap: 12px; }
  .sidebar { grid-template-columns: 1fr; }
  .workbench-footer { padding: 12px; }
  .controls { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .icon-btn { width: 100%; padding: 8px; }
}
@media (prefers-reduced-motion: reduce) { *, *::before, *::after { transition-duration: .01ms !important; } }