:root {
    --bg: #ffffff;
    --bg-elevated: #f7f8fa;
    --surface: #ffffff;
    --surface-2: #eef2f7;
    --border: #e2e5ea;
    --text: #101828;
    --text-dim: #475467;
    --text-faint: #98a2b3;
    --accent: #1f8fce;
  }

  * { box-sizing: border-box; }

  html, body {
    margin: 0;
    height: 100%;
    background: var(--bg);
    color: var(--text);
    font-family: "IBM Plex Sans KR", "Pretendard", -apple-system, sans-serif;
  }

  body {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    overflow-x: hidden;
  }

  .mono {
    font-family: "IBM Plex Mono", ui-monospace, monospace;
  }

  header {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    gap: 1rem;
    padding: 1.4rem clamp(1rem, 3vw, 2.4rem) 1.1rem;
    border-bottom: 1px solid var(--border);
    flex-wrap: wrap;
  }

  .brand {
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
  }

  .eyebrow {
    font-size: 0.72rem;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: var(--accent);
    font-weight: 600;
    transition: color 0.4s ease;
  }

  h1 {
    margin: 0;
    font-size: clamp(1.3rem, 2.2vw, 1.7rem);
    font-weight: 700;
    letter-spacing: -0.01em;
    text-wrap: balance;
  }

  .lede {
    margin: 0;
    max-width: 34ch;
    font-size: 0.88rem;
    color: var(--text-dim);
    line-height: 1.5;
  }

  main {
    flex: 1;
    display: grid;
    grid-template-columns: 272px minmax(0, 1fr);
    gap: 1px;
    background: var(--border);
  }

  @media (max-width: 860px) {
    main { grid-template-columns: minmax(0, 1fr); }
  }

  aside {
    min-width: 0;
    background: var(--bg-elevated);
    padding: 1.2rem;
    display: flex;
    flex-direction: column;
    gap: 0.7rem;
  }

  .rail-label {
    font-size: 0.7rem;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    color: var(--text-faint);
    margin: 0 0 0.2rem 0.1rem;
  }

  .type-card {
    text-align: left;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 0.85rem 0.95rem;
    cursor: pointer;
    color: var(--text);
    display: flex;
    flex-direction: column;
    gap: 0.3rem;
    transition: border-color 0.2s ease, background 0.2s ease, transform 0.15s ease;
  }

  .type-card:hover {
    border-color: var(--text-faint);
    transform: translateY(-1px);
  }

  .type-card:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
  }

  .type-card .row {
    display: flex;
    align-items: center;
    gap: 0.5rem;
  }

  .swatch {
    width: 9px;
    height: 9px;
    border-radius: 50%;
    background: var(--dot, #666);
    box-shadow: 0 0 0 3px transparent;
    transition: box-shadow 0.2s ease;
  }

  .type-card .kr {
    font-weight: 600;
    font-size: 0.95rem;
  }

  .type-card .en {
    font-family: "IBM Plex Mono", monospace;
    font-size: 0.66rem;
    letter-spacing: 0.1em;
    color: var(--text-faint);
  }

  .type-card p {
    margin: 0;
    font-size: 0.78rem;
    color: var(--text-dim);
    line-height: 1.5;
  }

  .type-card.is-active {
    background: var(--surface-2);
    border-color: var(--dot, var(--accent));
  }

  .type-card.is-active .swatch {
    box-shadow: 0 0 0 4px color-mix(in srgb, var(--dot, var(--accent)) 22%, transparent);
  }

  .rail-note {
    margin-top: auto;
    font-size: 0.72rem;
    color: var(--text-faint);
    line-height: 1.6;
    padding-top: 0.6rem;
    border-top: 1px solid var(--border);
  }

  .stage-col {
    min-width: 0;
    display: flex;
    flex-direction: column;
    background: var(--bg);
  }

  #stage {
    position: relative;
    flex: 1;
    min-height: 360px;
  }

  #stage-canvas {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    display: block;
    touch-action: none;
    cursor: grab;
  }

  #stage-canvas:active { cursor: grabbing; }

  .stage-vignette {
    position: absolute;
    inset: 0;
    pointer-events: none;
    background: radial-gradient(ellipse at center, transparent 45%, rgba(10,12,16,0.75) 100%);
  }

  .stage-controls {
    position: absolute;
    top: 1rem;
    right: 1rem;
    display: flex;
    gap: 0.5rem;
    z-index: 2;
  }

  .ctrl-btn {
    background: rgba(23,27,34,0.82);
    border: 1px solid var(--border);
    color: var(--text-dim);
    font-family: "IBM Plex Mono", monospace;
    font-size: 0.7rem;
    letter-spacing: 0.06em;
    padding: 0.5rem 0.75rem;
    border-radius: 7px;
    cursor: pointer;
    backdrop-filter: blur(6px);
  }

  .ctrl-btn:hover { color: var(--text); border-color: var(--text-faint); }

  .ctrl-btn.is-on {
    color: var(--accent);
    border-color: var(--accent);
  }

  .stage-hint {
    position: absolute;
    left: 1rem;
    bottom: 1rem;
    font-family: "IBM Plex Mono", monospace;
    font-size: 0.68rem;
    letter-spacing: 0.04em;
    color: var(--text-faint);
    background: rgba(23,27,34,0.7);
    padding: 0.4rem 0.65rem;
    border-radius: 6px;
    z-index: 2;
  }

  .spec-strip {
    min-width: 0;
    border-top: 1px solid var(--border);
    background: var(--bg-elevated);
    padding: 1rem clamp(1rem, 3vw, 2.4rem);
    display: flex;
    align-items: center;
    gap: clamp(1rem, 3vw, 2.6rem);
    overflow-x: auto;
  }

  #spec-grid {
    display: grid;
    grid-auto-flow: column;
    grid-template-rows: auto auto;
    column-gap: clamp(1.2rem, 3vw, 2.6rem);
    row-gap: 0.25rem;
    flex: 1;
  }

  .spec-label {
    font-size: 0.65rem;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--text-faint);
    white-space: nowrap;
  }

  .spec-value {
    font-family: "IBM Plex Mono", monospace;
    font-size: 0.88rem;
    font-weight: 500;
    color: var(--accent);
    white-space: nowrap;
    font-variant-numeric: tabular-nums;
    transition: color 0.4s ease;
  }

  footer {
    padding: 0.8rem clamp(1rem, 3vw, 2.4rem) 1.1rem;
    font-size: 0.7rem;
    color: var(--text-faint);
    background: var(--bg-elevated);
  }

  @media (prefers-reduced-motion: reduce) {
    .type-card, .ctrl-btn { transition: none; }
  }