:root{
  --bg:#f5f4f0; --surface:#fbfbf9; --panel:#ffffff; --panel-soft:#f7f6f2;
  --ink:#1c1c1a; --ink-hover:#3a3935; --ink-2:#55534d; --sub:#7a776f; --muted:#8a877f;
  --line:#e3e1db; --line-2:#dcdad3; --line-3:#efeee9; --hover:#efeee9; --soft:#f3f2ee; --track:#ebe9e3;
  --accent:#2f5bff;
  --paper:#fffdf6; --grid:rgba(47,91,255,.09);
  --font:"IBM Plex Sans KR",sans-serif; --mono:"JetBrains Mono",monospace;
}
*{box-sizing:border-box}
[hidden]{display:none !important}
body{margin:0;background:var(--bg);color:var(--ink);font-family:var(--font);-webkit-font-smoothing:antialiased}
button{font:inherit;color:inherit}
.mono-label{font-family:var(--mono);font-size:11px;letter-spacing:.12em;color:var(--muted)}
.app{min-height:100vh;display:flex;flex-direction:column}
.topbar{display:flex;align-items:center;justify-content:space-between;gap:16px;padding:16px 28px;border-bottom:1px solid var(--line);background:var(--surface);flex-wrap:wrap}
.brand{display:flex;align-items:baseline;gap:14px;min-width:0;flex-wrap:wrap}
.brand-title{margin:0;font-size:17px;font-weight:700;letter-spacing:-.01em}
.actions{display:flex;gap:8px;flex-wrap:wrap}
.btn{height:36px;padding:0 14px;background:transparent;border:1px solid var(--line-2);border-radius:999px;font-size:13px;cursor:pointer}
.btn:hover{background:var(--hover)}
.btn:disabled{opacity:.4;cursor:default}
.btn:disabled:hover{background:transparent}
.btn--solid{background:var(--ink);color:#fff;border:none;font-weight:500}
.btn--solid:hover{background:var(--ink-hover)}
:focus-visible{outline:2px solid var(--accent);outline-offset:2px}
@media (max-width:640px){ .topbar{padding:14px 16px} }

/* ---------- 레이아웃 ---------- */
.gd{flex:1;display:flex;flex-wrap:wrap;align-items:stretch}
.stage-wrap{flex:999 1 520px;min-width:0;padding:20px 28px 28px;display:flex;flex-direction:column;gap:14px}
.panel{flex:1 1 290px;max-width:100%;min-width:0;background:var(--panel);border-left:1px solid var(--line);padding:24px;display:flex;flex-direction:column;gap:24px}
.group{display:flex;flex-direction:column;gap:12px}
.group + .group{border-top:1px solid var(--line-3);padding-top:22px}

/* ---------- 도구 ---------- */
.toolbar{display:flex;gap:6px;flex-wrap:wrap}
.tool{display:inline-flex;align-items:center;gap:6px;height:38px;padding:0 14px 0 10px;border:1px solid var(--line-2);border-radius:999px;background:var(--panel);font-size:13px;cursor:pointer;transition:background .15s,color .15s,transform .15s}
.tool:hover{background:var(--hover)}
.tool[aria-checked="true"]{background:var(--accent);border-color:var(--accent);color:#fff;transform:translateY(-1px);box-shadow:0 8px 18px -10px rgba(47,91,255,.9)}
.tool-ico{font-size:15px;line-height:1}

/* ---------- 종이 ---------- */
.stage{position:relative;flex:1 0 auto;min-height:420px;height:clamp(420px,calc(100vh - 260px),700px);border-radius:18px;overflow:hidden;
  background-color:var(--paper);
  background-image:linear-gradient(var(--grid) 1px,transparent 1px),linear-gradient(90deg,var(--grid) 1px,transparent 1px);
  background-size:24px 24px;background-position:-1px -1px;
  border:1px solid #e6e1d2;
  box-shadow:0 1px 0 #fff inset,0 2px 0 #e6e1d2,0 24px 50px -30px rgba(28,28,26,.35);
  touch-action:none;user-select:none;-webkit-user-select:none;cursor:crosshair;outline:none}
.stage::before{content:"";position:absolute;left:44px;top:0;bottom:0;width:2px;background:rgba(255,90,60,.22);pointer-events:none}
.stage:focus-visible{box-shadow:0 0 0 3px var(--accent),0 24px 50px -30px rgba(28,28,26,.35)}
.stage[data-tool="grab"]{cursor:grab}
.stage[data-tool="grab"].is-grabbing{cursor:grabbing}
.stage[data-tool="erase"]{cursor:cell}
.stage canvas{position:absolute;inset:0;width:100%;height:100%;display:block}
.stage-meta{position:absolute;right:14px;top:12px;display:flex;gap:12px;font-family:var(--mono);font-size:10.5px;letter-spacing:.08em;color:var(--muted);pointer-events:none}
.stage-meta b{color:var(--ink);font-weight:500}
#metaGravity{color:var(--accent);font-weight:500}
.stage-hint{position:absolute;left:50%;top:44%;transform:translate(-50%,-50%) rotate(-2deg);margin:0;padding:10px 16px;background:#fff6a8;color:#3a3420;font-size:13.5px;box-shadow:0 10px 20px -12px rgba(0,0,0,.35);pointer-events:none;transition:opacity .4s;max-width:calc(100% - 32px);text-align:center}
.stage-hint.is-hidden{opacity:0}

/* ---------- 중력 패드 ---------- */
.grav-wrap{display:flex;gap:18px;align-items:center}
.dpad{display:grid;grid-template-columns:repeat(3,40px);grid-template-rows:repeat(3,40px);gap:4px;flex-shrink:0}
.dir{border:1px solid var(--line-2);border-radius:12px;background:var(--surface);font-family:var(--mono);font-size:16px;cursor:pointer;transition:background .15s,color .15s}
.dir:hover{background:var(--hover)}
.dir[aria-checked="true"]{background:var(--accent);border-color:var(--accent);color:#fff}
.dir--up{grid-area:1/2}.dir--left{grid-area:2/1}.dir--zero{grid-area:2/2;font-size:12px;border-radius:50%}.dir--right{grid-area:2/3}.dir--down{grid-area:3/2}
.grav-side{flex:1;min-width:0;display:flex;flex-direction:column;gap:6px}
.note{margin:0;font-size:11.5px;line-height:1.5;color:var(--sub)}

/* ---------- 펜 ---------- */
.swatches{display:flex;flex-wrap:wrap;gap:8px}
.sw{width:30px;height:30px;border-radius:50%;border:2px solid var(--panel);box-shadow:0 0 0 1px var(--line-2);cursor:pointer;padding:0}
.sw[aria-checked="true"]{box-shadow:0 0 0 2px var(--ink)}
.sw--auto{background:conic-gradient(#2f5bff,#12a383,#f5b700,#ff5a3c,#b04dff,#2f5bff)}
.slider-row{display:flex;justify-content:space-between;align-items:center;gap:8px;font-size:13px;color:var(--ink-2)}
.slider-row output{font-family:var(--mono);font-size:12px;color:var(--ink)}
input[type=range]{width:100%;margin:0 0 4px;accent-color:var(--accent)}

.seg{display:flex;background:var(--soft);border-radius:999px;padding:3px;gap:2px}
.seg-btn{flex:1;height:32px;padding:0 10px;background:transparent;color:var(--sub);border:none;border-radius:999px;font-size:12.5px;cursor:pointer;white-space:nowrap}
.seg-btn[aria-checked="true"]{background:#fff;color:var(--ink);box-shadow:0 1px 3px rgba(0,0,0,.12);font-weight:500}

@media (max-width:640px){
  .stage-wrap{padding:16px}
  .stage{min-height:340px;height:60vh;border-radius:14px}
  .stage::before{left:28px}
  .toolbar{display:grid;grid-template-columns:repeat(4,1fr)}
  .tool{flex-direction:column;justify-content:center;gap:3px;height:54px;padding:0 4px;border-radius:14px;font-size:11.5px;white-space:nowrap}
  .tool-ico{font-size:17px}
  .panel{border-left:none;border-top:1px solid var(--line);padding:20px 16px 32px}
}
@media (prefers-reduced-motion:reduce){
  .tool,.dir,.stage-hint{transition:none}
  .tool[aria-checked="true"]{transform:none}
}

/* 다크 모드 (인쇄는 라이트 그대로) — 종이는 어두운 칠판 모눈으로 */
@media screen{
  :root[data-theme="dark"]{
    color-scheme:dark;
    --bg:#131419; --surface:#181a20; --panel:#1d1f26; --panel-soft:#22242c;
    --ink:#eaebf0; --ink-hover:#ffffff; --ink-2:#c6c8d2; --sub:#9ea1ad; --muted:#898c99;
    --line:#2c2e37; --line-2:#373a44; --line-3:#25272f; --hover:#292b34; --soft:#252730; --track:#33353f;
    --accent:#5c80ff;
    --paper:#191b23; --grid:rgba(120,150,255,.09);
    --cv-shadow:rgba(0,0,0,.35); --cv-wall-dash:rgba(25,27,35,.6);
  }
  :root[data-theme="dark"] .btn--solid{color:var(--bg)}
  :root[data-theme="dark"] .stage{border-color:var(--line-2);box-shadow:0 24px 50px -30px rgba(0,0,0,.7)}
  :root[data-theme="dark"] .stage:focus-visible{box-shadow:0 0 0 3px var(--accent),0 24px 50px -30px rgba(0,0,0,.7)}
  :root[data-theme="dark"] .stage::before{background:rgba(255,110,80,.22)}
  :root[data-theme="dark"] .stage-hint{background:#e8dd8a;box-shadow:0 10px 20px -12px rgba(0,0,0,.7)}
  :root[data-theme="dark"] .seg-btn[aria-checked="true"]{background:var(--hover);box-shadow:0 1px 3px rgba(0,0,0,.4)}
  :root[data-theme="dark"] .sw{border-color:var(--panel)}
  :root[data-theme="dark"] .sw[data-c="5"]{background:var(--ink) !important}
}
/* 영어판: 좁은 중력 칸에서 라벨과 입력칸이 줄바꿈되도록 */
html[lang="en"] .grav-side .slider-row{flex-wrap:wrap;row-gap:4px}