:root {
  color-scheme: light dark;
  --background: #f6f7f8;
  --surface: #ffffff;
  --surface-soft: #eef1f3;
  --text: #20252a;
  --muted: #66717b;
  --border: #d9dee2;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --focus: rgba(37, 99, 235, 0.25);
  --overlay: rgba(37, 99, 235, 0.16);
  font-family: ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }

.icon-sprite {
  position: absolute;
  width: 0;
  height: 0;
  overflow: hidden;
}

.icon {
  width: 1em;
  height: 1em;
  flex: none;
  fill: currentColor;
}

body {
  margin: 0;
  color: var(--text);
  background: var(--background);
  line-height: 1.5;
}

.container {
  width: min(1440px, calc(100% - 2rem));
  margin-inline: auto;
}

header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding-block: 1.5rem 1rem;
}

h1, h2, p { margin: 0; }
h1 { font-size: clamp(1.35rem, 3vw, 1.75rem); letter-spacing: -0.025em; }
h2 { font-size: 1rem; }
header p, .panel-heading p, .hint { color: var(--muted); font-size: 0.875rem; }

button, select, input {
  font: inherit;
}

button, .file-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 2.65rem;
  padding: 0.6rem 1rem;
  border: 1px solid var(--accent);
  border-radius: 0.5rem;
  color: #fff;
  background: var(--accent);
  font-weight: 650;
  cursor: pointer;
  gap: 0.5rem;
}

button:hover, .file-button:hover { background: var(--accent-hover); }
button:focus-visible, .file-button:focus-within, select:focus, input:focus {
  outline: 3px solid var(--focus);
  outline-offset: 1px;
}

button.secondary {
  border-color: var(--border);
  color: var(--text);
  background: var(--surface);
}
button.secondary:hover { background: var(--surface-soft); }
button:disabled { opacity: 0.45; cursor: not-allowed; }
button:disabled:hover { background: var(--surface); }
button.compact { min-height: 2.2rem; padding: 0.4rem 0.7rem; font-size: 0.82rem; white-space: nowrap; }
.file-button input { position: absolute; width: 1px; height: 1px; opacity: 0; }

.workspace {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 1rem;
}

.view-switch, .mobile-only { display: none; }
.panel-actions { display: flex; align-items: center; gap: 0.5rem; }
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

article, .controls {
  padding: 1rem;
  border: 1px solid var(--border);
  border-radius: 0.75rem;
  background: var(--surface);
  box-shadow: 0 1px 2px rgba(20, 30, 40, 0.04);
}

.panel-heading {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  min-height: 2.5rem;
  margin-bottom: 0.8rem;
}

.badge {
  padding: 0.18rem 0.5rem;
  border-radius: 99px;
  color: var(--accent);
  background: var(--overlay);
  font-size: 0.72rem;
  font-weight: 700;
}

.canvas-shell {
  position: relative;
  display: grid;
  min-height: 260px;
  overflow: hidden;
  place-items: center;
  border-radius: 0.5rem;
  background-color: #161a1d;
  background-image:
    linear-gradient(45deg, #1e2327 25%, transparent 25%),
    linear-gradient(-45deg, #1e2327 25%, transparent 25%),
    linear-gradient(45deg, transparent 75%, #1e2327 75%),
    linear-gradient(-45deg, transparent 75%, #1e2327 75%);
  background-position: 0 0, 0 8px, 8px -8px, -8px 0;
  background-size: 16px 16px;
}

canvas { display: block; width: 100%; height: auto; max-height: 68vh; object-fit: contain; touch-action: none; }
#input-canvas { cursor: crosshair; }
#input-canvas.dragging { cursor: grabbing; }
#input-canvas:focus-visible { outline: 3px solid var(--accent); outline-offset: -3px; }
.result-shell canvas { width: auto; max-width: 100%; }
.drop-message, .rendering {
  position: absolute;
  padding: 0.7rem 1rem;
  border-radius: 0.5rem;
  color: white;
  background: rgba(0, 0, 0, 0.75);
  pointer-events: none;
}
.drop-message { display: none; border: 1px dashed rgba(255,255,255,.7); }
.drop-zone.is-over .drop-message { display: block; }
.drop-zone.is-over canvas { opacity: 0.45; }

.controls {
  display: flex;
  align-items: end;
  gap: 1rem;
  margin-top: 1rem;
}

.control-group { display: grid; gap: 0.35rem; min-width: 140px; }
.control-group label { font-size: 0.78rem; font-weight: 700; color: var(--muted); }
select, input[type="number"] {
  height: 2.65rem;
  padding: 0.45rem 0.65rem;
  border: 1px solid var(--border);
  border-radius: 0.45rem;
  color: var(--text);
  background: var(--surface);
}
.ratio-fields { display: flex; align-items: center; gap: 0.4rem; }
.ratio-fields input { width: 4.5rem; }
.button-group { display: flex; gap: 0.5rem; margin-left: auto; }
.hint { margin: 0.7rem 0 1.5rem; text-align: right; }

@media (max-width: 850px) {
  .workspace { grid-template-columns: 1fr; }
  .controls { flex-wrap: wrap; align-items: end; }
  .control-group { flex: 1; }
  .button-group { width: 100%; }
  .button-group button { flex: 1; }
  canvas { max-height: 56vh; }
}

@media (max-width: 600px) {
  .view-switch {
    position: sticky;
    top: max(0.5rem, env(safe-area-inset-top));
    z-index: 20;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 0.35rem;
    padding: 0.35rem;
    border: 1px solid var(--border);
    border-radius: 0.65rem;
    background: var(--surface);
    background: color-mix(in srgb, var(--surface) 94%, transparent);
    box-shadow: 0 4px 16px rgba(20, 30, 40, 0.1);
    backdrop-filter: blur(10px);
  }
  .view-switch button {
    min-height: 2.6rem;
    padding: 0.45rem;
    border-color: transparent;
  }
  .view-switch button[aria-pressed="true"] {
    color: #fff;
    border-color: var(--accent);
    background: var(--accent);
  }
  .view-button.has-update::after {
    width: 0.45rem;
    height: 0.45rem;
    margin-left: 0.35rem;
    border-radius: 50%;
    background: #f59e0b;
    content: "";
  }
  .workspace[data-mobile-view="input"] .output-panel,
  .workspace[data-mobile-view="output"] .input-panel { display: none; }
  .mobile-only { display: inline-flex; }
  .controls { gap: 0.75rem; }
  .control-group { min-width: calc(50% - 0.4rem); }
  button, .file-button, select, input[type="number"] { min-height: 3rem; }
  .button-group { display: grid; grid-template-columns: repeat(3, 1fr); }
  .button-group button { padding-inline: 0.4rem; }

  body.focus-editing { overflow: hidden; }
  body.focus-editing .input-panel {
    position: fixed;
    inset: 0;
    z-index: 100;
    display: flex;
    flex-direction: column;
    padding: max(0.75rem, env(safe-area-inset-top)) max(0.75rem, env(safe-area-inset-right)) max(0.75rem, env(safe-area-inset-bottom)) max(0.75rem, env(safe-area-inset-left));
    border: 0;
    border-radius: 0;
  }
  body.focus-editing .input-panel .canvas-shell {
    flex: 1;
    min-height: 0;
  }
  body.focus-editing #input-canvas {
    width: auto;
    max-width: 100%;
    height: auto;
    max-height: 100%;
  }
}

@media (max-width: 480px) {
  .container { width: min(100% - 1rem, 1440px); }
  header { padding-top: 1rem; }
  header p { display: none; }
  article, .controls { padding: 0.75rem; }
  .canvas-shell { min-height: 180px; }
  .control-group { min-width: calc(50% - 0.5rem); }
}

@media (prefers-color-scheme: dark) {
  :root {
    --background: #111416;
    --surface: #1a1e21;
    --surface-soft: #242a2e;
    --text: #edf1f4;
    --muted: #a8b1b8;
    --border: #343b40;
    --accent: #5b8def;
    --accent-hover: #79a3f5;
    --focus: rgba(91, 141, 239, 0.3);
    --overlay: rgba(91, 141, 239, 0.18);
  }
}