/* ══════════════════════════════════════════════════════════════════
   app.css — Happy Light Sandbox.

   Same warm-ink token set as the rest of the suite, so theme.js's
   [data-theme] switch drives this page the way it drives the arcade,
   Pixel Studio, Triggers and Journal. Dark is the bare :root; light
   overrides only what actually changes.

   theme.js always stamps an explicit data-theme before first paint
   (resolving "auto" against the OS itself), which is why there is no
   prefers-color-scheme block here — a media query would be a second,
   competing source of truth.

   The --sb-* tokens are the CANVAS palette. render.js reads them with
   getComputedStyle, so the stage repaints in the right theme without a
   second colour table in JavaScript.
   ══════════════════════════════════════════════════════════════════ */
:root{
  --bg:#0b0a0d; --bg-2:#16131a;
  --panel:rgba(29,25,34,.82); --panel-solid:#1d1922;
  --line:rgba(184,175,164,.20); --line-hot:rgba(245,158,11,.45);
  --ink:#f5f1ea; --ink-dim:#b8afa4; --ink-faint:#6b635a;
  --brand:#f59e0b; --brand-2:#a78bfa;
  --ok:#4ee8a5; --warn:#fbbf24; --bad:#f87171;
  --surf:rgba(43,37,51,.72);
  --shadow:4px 4px 0 rgba(0,0,0,.45);
  --logo-glow:1; --logo-glow-color:#f59e0b; --logo-bulb:#d9a441;
  --logo-glass-hi:#fffdf6; --logo-glass-lo:#f8e3b6; --logo-face:#8a6a3b;
  --font:"Inter Variable","Inter",ui-sans-serif,system-ui,-apple-system,"Segoe UI",sans-serif;
  --mono:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
  --r:12px;

  /* canvas palette — read by render.js */
  --sb-sky:#100d16;
  --sb-grid:rgba(184,175,164,.11);
  --sb-solid-top:#8d84ac;
  --sb-solid-face:#4b4459;
  --sb-solid-side:#37313f;
  --sb-oneway:#48c8dd;
  --sb-hazard:#e05b7a;
  --sb-spawn:#9ec95a;
  --sb-sel:#f59e0b;
  --sb-text:#f5f1ea;
  --sb-shadow:rgba(0,0,0,.55);
}
:root[data-theme="light"]{
  --bg:#faf8f4; --bg-2:#f1ece2;
  --panel:rgba(255,253,247,.92); --panel-solid:#fffdf7;
  --line:rgba(90,74,54,.22); --line-hot:rgba(180,83,9,.42);
  --ink:#241f18; --ink-dim:#5b5145; --ink-faint:#7d7264;
  --brand:#b45309; --brand-2:#6d28d9;
  --ok:#047857; --warn:#8c6510; --bad:#b91c1c;
  --surf:rgba(241,236,226,.80);
  --shadow:4px 4px 0 rgba(90,74,54,.22);
  --logo-glow:0; --logo-bulb:#a86f18;
  --logo-glass-hi:#fffaec; --logo-glass-lo:#f2d79c; --logo-face:#6b4d22;

  /* The stage is not simply inverted. A near-white stage would make dark
     pixel art float and every shadow read as dirt, so it stays a warm
     mid-paper with the geometry DARKER than the ground — the value
     relationship that keeps a sprite legible either way. */
  --sb-sky:#e9e2d4;
  --sb-grid:rgba(90,74,54,.16);
  --sb-solid-top:#a99a86;
  --sb-solid-face:#7d6f5e;
  --sb-solid-side:#635747;
  --sb-oneway:#1f7f93;
  --sb-hazard:#b91c48;
  --sb-spawn:#3f6f1f;
  --sb-sel:#b45309;
  --sb-text:#241f18;
  --sb-shadow:rgba(90,74,54,.45);
}

*{box-sizing:border-box}
input[type=checkbox]{accent-color:var(--brand)}
[hidden]{display:none !important}

html{color-scheme:dark;height:100%}
:root[data-theme="light"]{color-scheme:light}

body{
  margin:0;background:var(--bg);color:var(--ink);
  font-family:var(--font);font-size:15px;line-height:1.55;
  -webkit-font-smoothing:antialiased;
  /* A fixed frame: the stage fills what is left and the side panel scrolls
     on its own, so the page itself never scrolls. Flex column rather than a
     height calculation — the bar and the alert both change height (they wrap
     when narrow, and the alert comes and goes), and subtracting guessed
     constants is what clips a panel footer. 100dvh so a collapsing mobile
     URL bar leaves no dead strip. */
  height:100dvh;
  display:flex;flex-direction:column;
  overflow:hidden;
}
.sb-bar,.sb-alert{flex:none}

a{color:var(--brand)}
a:focus-visible,button:focus-visible,input:focus-visible,select:focus-visible,
summary:focus-visible,canvas:focus-visible{
  outline:2px solid var(--brand);outline-offset:2px;border-radius:4px;
}

.skip{position:absolute;left:-9999px;top:0;background:var(--panel-solid);
  color:var(--ink);padding:.6rem .9rem;z-index:80;border-radius:0 0 var(--r) 0}
.skip:focus{left:0}

/* ── brand lockup ──
   inline-flex + column stacks the subtitle under the mark. It must stay
   inline-flex: the lockup is taller than its line box (the viewBox reserves
   headroom for the bulb), so as a plain inline element it escapes and the
   bar clips the bulb. */
.wordmark{font-weight:700;letter-spacing:-.03em;line-height:1;
  display:inline-flex;flex-direction:column;align-items:center;gap:.3rem}
.wordmark.small{font-size:1.2rem}
.wordmark .hl-lockup{height:2em;width:auto;display:inline-block;
  color:var(--ink);flex:none}
.wm-b{color:var(--ink-dim);font-size:max(.62rem,.16em);font-weight:700;
  letter-spacing:.26em;text-indent:.26em;text-transform:uppercase;line-height:1}

/* ── top bar ── */
.sb-bar{display:flex;align-items:center;gap:.9rem;flex-wrap:wrap;
  padding:.55rem .9rem;background:var(--panel);backdrop-filter:blur(8px);
  border-bottom:1px solid var(--line);z-index:40}
.sb-home{text-decoration:none;flex:none}
.sb-title{font-size:.78rem;letter-spacing:.14em;text-transform:uppercase;
  color:var(--ink-faint);font-weight:600}
.sb-bar-actions{margin-left:auto;display:flex;align-items:center;gap:.5rem;flex-wrap:wrap}

.sb-btn{appearance:none;font:inherit;font-size:.82rem;cursor:pointer;
  color:var(--ink);background:var(--surf);border:1px solid var(--line);
  border-radius:999px;padding:.32rem .8rem}
.sb-btn:hover{border-color:var(--line-hot)}
.sb-btn:disabled{opacity:.45;cursor:default}
.sb-btn:disabled:hover{border-color:var(--line)}
.sb-btn-quiet{background:none}
.sb-btn-wide{width:100%;text-align:center}
.sb-btn[aria-pressed="true"]{background:var(--brand);color:#1a1206;font-weight:700;
  border-color:transparent}
:root[data-theme="light"] .sb-btn[aria-pressed="true"]{color:#fff}

.sb-seg{display:inline-flex;border:1px solid var(--line);border-radius:999px;
  overflow:hidden;background:var(--surf)}
.sb-seg button{appearance:none;background:none;border:0;color:var(--ink-dim);
  font:inherit;font-size:.78rem;padding:.3rem .7rem;cursor:pointer;white-space:nowrap}
.sb-seg button.on{background:var(--brand);color:#1a1206;font-weight:700}
:root[data-theme="light"] .sb-seg button.on{color:#fff}

/* ── bar menu ── same <details>/<summary> pattern as the siblings ── */
.hl-menu{position:relative}
.hl-menu-summary{display:flex;align-items:center;gap:.45rem;cursor:pointer;list-style:none;
  padding:.3rem .7rem;border:1px solid var(--line);border-radius:999px;background:var(--surf);
  color:var(--ink-dim);font-size:.78rem;user-select:none}
.hl-menu-summary::-webkit-details-marker{display:none}
.hl-menu-summary:hover{border-color:var(--line-hot);color:var(--ink)}
.hl-menu-bars{width:.85rem;height:.7rem;flex:none;
  border-top:2px solid currentColor;border-bottom:2px solid currentColor;position:relative}
.hl-menu-bars::after{content:"";position:absolute;left:0;right:0;top:calc(50% - 1px);
  border-top:2px solid currentColor}
.hl-menu-panel{position:absolute;right:0;top:calc(100% + .35rem);z-index:60;
  min-width:15rem;display:flex;flex-direction:column;padding:.3rem;
  border:1px solid var(--line);border-radius:.6rem;
  background:var(--panel-solid);box-shadow:var(--shadow)}
.hl-menu-head{margin:.45rem .55rem .2rem;font-size:.62rem;letter-spacing:.08em;
  text-transform:uppercase;color:var(--ink-faint)}
.hl-menu-head:first-child{margin-top:.2rem}
.hl-menu-item{appearance:none;background:none;border:0;cursor:pointer;font:inherit;
  font-size:.85rem;color:var(--ink);text-align:left;text-decoration:none;
  padding:.45rem .55rem;border-radius:.4rem}
.hl-menu-item:hover{background:var(--line)}
.hl-menu-item:focus-visible{outline:2px solid var(--brand);outline-offset:-2px}
.hl-menu-seg{margin:.15rem .55rem .3rem;align-self:flex-start}
.hl-menu-check{display:flex;align-items:center;gap:.5rem;font-size:.85rem;
  padding:.35rem .55rem;cursor:pointer;color:var(--ink)}

/* ── alerts ── */
.sb-alert{margin:0;padding:.6rem .9rem;font-size:.84rem;
  border-bottom:1px solid var(--line);background:var(--bg-2)}
.sb-alert.ok{background:color-mix(in srgb,var(--ok) 16%,var(--bg-2));color:var(--ink)}
.sb-alert.warn{background:color-mix(in srgb,var(--warn) 18%,var(--bg-2));color:var(--ink)}
.sb-alert.bad{background:color-mix(in srgb,var(--bad) 20%,var(--bg-2));color:var(--ink)}

/* ── frame ── */
.sb-main{
  display:grid;
  grid-template-columns:minmax(0,1fr) clamp(16rem,24vw,22rem);
  flex:1;
  min-height:0;      /* without this a grid child refuses to shrink */
}

/* ── stage ── */
.sb-stage-wrap{position:relative;min-width:0;min-height:0;display:flex}
.sb-stage{
  flex:1;width:100%;height:100%;display:block;
  background:var(--sb-sky);
  /* The canvas is the interaction surface: no text selection, and a crosshair
     while building so it is obvious the click will draw rather than pan. */
  user-select:none;touch-action:none;
}
body.is-building .sb-stage{cursor:crosshair}

.sb-hud{position:absolute;left:.6rem;bottom:.55rem;margin:0;
  font-family:var(--mono);font-size:.7rem;color:var(--ink-dim);
  background:color-mix(in srgb,var(--bg) 78%,transparent);
  padding:.25rem .5rem;border-radius:.4rem;pointer-events:none;
  max-width:calc(100% - 1.2rem)}

/* Build toolbar floats over the stage so the stage stays as large as it can. */
.sb-build{position:absolute;left:.6rem;top:.6rem;right:.6rem;
  display:flex;align-items:center;gap:.45rem;flex-wrap:wrap;
  padding:.4rem .5rem;border:1px solid var(--line);border-radius:.6rem;
  background:color-mix(in srgb,var(--panel-solid) 92%,transparent);
  box-shadow:var(--shadow)}
.sb-build-sep{width:1px;align-self:stretch;background:var(--line)}
.sb-build-hint{font-size:.72rem;color:var(--ink-faint);margin-left:auto}

/* ── side panel ── */
.sb-side{display:flex;flex-direction:column;min-height:0;min-width:0;
  border-left:1px solid var(--line);background:var(--bg-2);
  overflow-y:auto;overscroll-behavior:contain}

.sb-group{border-bottom:1px solid var(--line)}
.sb-group>summary{cursor:pointer;list-style:none;padding:.55rem .7rem;
  font-size:.7rem;letter-spacing:.1em;text-transform:uppercase;
  color:var(--ink-dim);font-weight:700;display:flex;align-items:center;gap:.4rem}
.sb-group>summary::-webkit-details-marker{display:none}
.sb-group>summary::before{content:"▸";font-size:.7rem;color:var(--ink-faint)}
.sb-group[open]>summary::before{content:"▾"}
.sb-group>summary:hover{color:var(--ink)}
.sb-group-body{padding:.15rem .7rem .8rem;display:grid;gap:.5rem}

.sb-note{margin:0;font-size:.74rem;color:var(--ink-faint);line-height:1.45}
.sb-sprite-name{margin:0;font-family:var(--mono);font-size:.74rem;color:var(--ink-dim)}

.sb-row{display:flex;gap:.4rem;align-items:center}
.sb-row-split{justify-content:space-between}
.sb-input{flex:1;min-width:0;font:inherit;font-size:.82rem;color:var(--ink);
  background:var(--panel-solid);border:1px solid var(--line);
  border-radius:999px;padding:.3rem .7rem}
.sb-input::placeholder{color:var(--ink-faint)}

.sb-field{display:flex;align-items:center;gap:.5rem;font-size:.78rem;color:var(--ink-dim)}
.sb-field>span{flex:none;min-width:3rem}
.sb-field select,.sb-field input[type=range]{flex:1;min-width:0}
.sb-field select{font:inherit;font-size:.82rem;color:var(--ink);
  background:var(--panel-solid);border:1px solid var(--line);
  border-radius:.4rem;padding:.28rem .4rem}
.sb-field output{font-family:var(--mono);font-size:.74rem;min-width:2rem;text-align:right}

/* ── frame timeline ──
   A scrolling column, capped so a 20-frame animation cannot push the level
   list off the screen. Each row is a fixed grid so the numbers line up
   down the column rather than jittering with the digit count. */
.sb-frames{display:grid;gap:.25rem;max-height:38vh;overflow-y:auto;
  overscroll-behavior:contain;padding-right:.15rem}
.sb-frame{display:grid;grid-template-columns:auto 1.1rem 4.2rem auto 3.6rem auto;
  align-items:center;gap:.3rem}
.sb-frame-thumb{width:2rem;height:2rem;flex:none;border:1px solid var(--line);
  border-radius:.25rem;background:var(--sb-sky);
  /* Pixel art must not be smoothed when the thumbnail scales it up. */
  image-rendering:pixelated}
.sb-frame-n{font-family:var(--mono);font-size:.7rem;color:var(--ink-faint);text-align:right}
.sb-frame input{font:inherit;font-family:var(--mono);font-size:.74rem;color:var(--ink);
  background:var(--panel-solid);border:1px solid var(--line);
  border-radius:.3rem;padding:.2rem .3rem;width:100%;min-width:0}
.sb-frame input::placeholder{color:var(--ink-faint)}
.sb-frame-u{font-size:.68rem;color:var(--ink-faint)}
.sb-cycle{font-family:var(--mono);font-size:.7rem;color:var(--ink-faint)}

/* ── level list ── */
.sb-levels{list-style:none;margin:0;padding:0;display:grid;gap:.15rem}
.sb-level{display:flex;align-items:stretch;gap:.2rem;border-radius:.4rem}
.sb-level:hover{background:var(--surf)}
.sb-level.on{background:var(--surf);box-shadow:inset 2px 0 0 var(--brand)}
.sb-level-open{appearance:none;background:none;border:0;cursor:pointer;font:inherit;
  font-size:.82rem;color:var(--ink);text-align:left;flex:1;min-width:0;
  padding:.35rem .45rem;border-radius:.4rem;
  display:flex;align-items:center;gap:.4rem;
  overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.sb-level-n{margin-left:auto;font-family:var(--mono);font-size:.68rem;
  color:var(--ink-faint);flex:none}
.sb-level-del{appearance:none;background:none;border:0;cursor:pointer;
  color:var(--ink-faint);font-size:1rem;line-height:1;padding:0 .45rem;border-radius:.4rem}
.sb-level-del:hover{color:var(--bad)}

.sb-keys{margin:0;display:grid;grid-template-columns:auto 1fr;gap:.2rem .6rem;font-size:.76rem}
.sb-keys dt{font-family:var(--mono);color:var(--ink-dim);white-space:nowrap}
.sb-keys dd{margin:0;color:var(--ink-faint)}
.sb-usage{font-family:var(--mono);font-size:.68rem;color:var(--ink-faint)}

/* ── drop overlay ── */
.sb-drop{position:fixed;inset:0;z-index:70;display:grid;place-items:center;
  background:color-mix(in srgb,var(--bg) 75%,transparent);
  border:3px dashed var(--brand);pointer-events:none}
.sb-drop span{font-size:1rem;font-weight:600;color:var(--ink);
  background:var(--panel-solid);padding:.7rem 1.1rem;border-radius:var(--r);
  box-shadow:var(--shadow)}
.sb-drop code{font-family:var(--mono);font-size:.85em}

/* ══ narrow ══
   Below 900px the side panel goes under the stage instead of beside it. The
   stage keeps a fixed share of the viewport rather than a share of the grid,
   because a 1fr row in a scrolling column collapses to its content — which
   for a canvas is zero. */
@media (max-width:900px){
  body{height:auto;min-height:100dvh;overflow:auto}
  .sb-main{grid-template-columns:minmax(0,1fr);grid-template-rows:auto auto}
  .sb-stage-wrap{height:min(60vh,26rem)}
  .sb-side{border-left:0;border-top:1px solid var(--line);overflow:visible}
  .sb-frames{max-height:none}
  .sb-bar{position:static}
  .sb-build{position:static;margin:.5rem;box-shadow:none}
  .sb-build-hint{margin-left:0;width:100%}
}

@media (max-width:560px){
  .sb-title{display:none}
  .sb-seg button{padding:.3rem .5rem;font-size:.72rem}
  .sb-bar{gap:.5rem;padding:.5rem .6rem}
}

@media (prefers-reduced-motion:reduce){
  *{transition:none !important}
}