/* ---------------------------------------------------------------------------
   QR Studio — a precise little instrument.
   Palette: cool paper + ink with a slight blue bias, one signal-vermillion
   accent that lives only in the UI chrome (the code itself stays true colour).
--------------------------------------------------------------------------- */
:root {
  color-scheme: light dark;

  --paper:      #eef0f4;   /* cool page ground            */
  --surface:    #ffffff;   /* panels                      */
  --surface-2:  #f5f6f9;   /* recessed fields             */
  --ink:        #191b21;   /* near-black, blue bias       */
  --ink-soft:   #4a4f5a;
  --muted:      #838b98;   /* cool grey                   */
  --line:       #dfe3ea;
  --line-strong:#c7cdd8;
  --accent:     #ff5330;   /* signal vermillion           */
  --accent-ink: #ffffff;
  --warn-bg:    #fff2ec;
  --warn-ink:   #a83417;

  --radius:   14px;
  --radius-sm:9px;
  --shadow:   0 1px 2px rgba(20,24,34,.05), 0 12px 32px -18px rgba(20,24,34,.28);
  --ff-sans:  ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --ff-mono:  ui-monospace, "SF Mono", "JetBrains Mono", "Cascadia Code", Menlo, Consolas, monospace;
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper:      #0e1014;
    --surface:    #171a21;
    --surface-2:  #10131a;
    --ink:        #eef1f6;
    --ink-soft:   #b8bfcc;
    --muted:      #7b8494;
    --line:       #262b35;
    --line-strong:#333a46;
    --accent:     #ff6242;
    --accent-ink: #17120f;
    --warn-bg:    #2a1712;
    --warn-ink:   #ff9d80;
    --shadow:     0 1px 2px rgba(0,0,0,.4), 0 16px 40px -20px rgba(0,0,0,.7);
  }
}
/* Manual toggle wins over the media query in both directions. */
:root[data-theme="light"] {
  --paper:#eef0f4; --surface:#fff; --surface-2:#f5f6f9; --ink:#191b21;
  --ink-soft:#4a4f5a; --muted:#838b98; --line:#dfe3ea; --line-strong:#c7cdd8;
  --accent:#ff5330; --accent-ink:#fff; --warn-bg:#fff2ec; --warn-ink:#a83417;
  --shadow:0 1px 2px rgba(20,24,34,.05), 0 12px 32px -18px rgba(20,24,34,.28);
}
:root[data-theme="dark"] {
  --paper:#0e1014; --surface:#171a21; --surface-2:#10131a; --ink:#eef1f6;
  --ink-soft:#b8bfcc; --muted:#7b8494; --line:#262b35; --line-strong:#333a46;
  --accent:#ff6242; --accent-ink:#17120f; --warn-bg:#2a1712; --warn-ink:#ff9d80;
  --shadow:0 1px 2px rgba(0,0,0,.4), 0 16px 40px -20px rgba(0,0,0,.7);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: var(--ff-sans);
  color: var(--ink);
  background: var(--paper);
  /* faint module-grid backdrop, on-theme for a QR tool */
  background-image:
    linear-gradient(var(--line) 1px, transparent 1px),
    linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 22px 22px;
  background-position: -1px -1px;
  min-height: 100vh;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

/* ---- Top bar ------------------------------------------------------------- */
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px clamp(16px, 4vw, 40px);
  max-width: 1120px;
  margin: 0 auto;
}
.wordmark { display: flex; align-items: center; gap: 12px; }
.wordmark__text {
  font-weight: 700;
  font-size: 1.25rem;
  letter-spacing: -0.02em;
}
.wordmark__accent { color: var(--accent); }
.glyph {
  width: 30px; height: 30px;
  border-radius: 8px;
  background: var(--ink);
  position: relative;
  flex: none;
}
.glyph::before, .glyph::after {
  content: "";
  position: absolute;
  background: var(--surface);
  border-radius: 2px;
}
.glyph::before { inset: 6px auto auto 6px; width: 8px; height: 8px; box-shadow: 10px 0 0 var(--surface), 0 10px 0 var(--surface); }
.glyph::after  { inset: auto 6px 6px auto; width: 5px; height: 5px; box-shadow: -8px 0 0 var(--accent); }

.topbar__meta { display: flex; align-items: center; gap: 12px; }
.badge {
  font-family: var(--ff-mono);
  font-size: .72rem;
  letter-spacing: .04em;
  text-transform: uppercase;
  color: var(--muted);
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  padding: 5px 11px;
}

.ghost-btn {
  display: inline-flex; align-items: center; gap: 7px;
  font: inherit; font-size: .85rem;
  color: var(--ink-soft);
  background: transparent;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  padding: 6px 12px;
  cursor: pointer;
  transition: border-color .15s, color .15s;
}
.ghost-btn:hover { border-color: var(--muted); color: var(--ink); }
.ghost-btn--sm { padding: 6px 10px; border-radius: var(--radius-sm); }
.theme-dot {
  width: 11px; height: 11px; border-radius: 50%;
  background: linear-gradient(135deg, var(--ink) 50%, var(--surface) 50%);
  border: 1px solid var(--line-strong);
}

/* ---- Workbench layout ---------------------------------------------------- */
.workbench {
  max-width: 1120px;
  margin: 0 auto;
  padding: 8px clamp(16px, 4vw, 40px) 40px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(340px, 460px);
  gap: 22px;
  align-items: start;
}
@media (max-width: 880px) {
  .workbench { grid-template-columns: 1fr; }
}

.panel {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}
.controls { padding: 22px; }
.stage {
  padding: 22px;
  position: sticky;
  top: 18px;
  display: flex;
  flex-direction: column;
  gap: 18px;
}
@media (max-width: 880px) {
  .stage { position: static; }
}

/* ---- Tabs ----------------------------------------------------------------- */
.tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  background: var(--surface-2);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  padding: 4px;
  margin-bottom: 20px;
}
.tab {
  flex: 1 1 auto;
  font: inherit; font-size: .86rem; font-weight: 550;
  color: var(--ink-soft);
  background: transparent;
  border: none;
  border-radius: 6px;
  padding: 8px 10px;
  cursor: pointer;
  white-space: nowrap;
  transition: background .15s, color .15s;
}
.tab:hover { color: var(--ink); }
.tab.is-active {
  background: var(--surface);
  color: var(--ink);
  box-shadow: 0 1px 2px rgba(20,24,34,.12);
}

/* ---- Forms ---------------------------------------------------------------- */
.form { display: none; flex-direction: column; gap: 14px; }
.form.is-active { display: flex; }

.field { display: flex; flex-direction: column; gap: 6px; }
.field__label {
  font-size: .74rem;
  font-weight: 600;
  letter-spacing: .04em;
  text-transform: uppercase;
  color: var(--muted);
}
.field-row { display: flex; gap: 14px; flex-wrap: wrap; }
.field-row .field { flex: 1 1 160px; }
.field--check {
  flex-direction: row;
  align-items: center;
  gap: 9px;
  align-self: flex-end;
  padding-bottom: 10px;
}
.field--check .field__label { text-transform: none; letter-spacing: 0; font-weight: 500; font-size: .9rem; color: var(--ink-soft); }

input[type="text"], input[type="email"], input[type="tel"], textarea, select {
  font: inherit;
  color: var(--ink);
  background: var(--surface-2);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-sm);
  padding: 10px 12px;
  width: 100%;
  transition: border-color .15s, box-shadow .15s;
}
textarea { resize: vertical; min-height: 64px; font-family: var(--ff-mono); font-size: .9rem; }
input:focus, textarea:focus, select:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent) 22%, transparent);
}
input[type="checkbox"] { width: 18px; height: 18px; accent-color: var(--accent); cursor: pointer; }

.rule { border: none; border-top: 1px solid var(--line); margin: 22px 0; }

/* ---- Options -------------------------------------------------------------- */
.options { display: flex; flex-direction: column; gap: 20px; }
.option { display: flex; flex-direction: column; gap: 9px; }
.option__label {
  font-size: .74rem; font-weight: 600; letter-spacing: .04em;
  text-transform: uppercase; color: var(--muted);
}
.option__label .mono { color: var(--accent); margin-left: 2px; }

.segmented {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 4px;
  background: var(--surface-2);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  padding: 4px;
}
.seg {
  font: inherit; font-weight: 650; font-family: var(--ff-mono);
  color: var(--ink-soft);
  background: transparent; border: none; border-radius: 6px;
  padding: 9px 0; cursor: pointer;
  transition: background .15s, color .15s;
}
.seg:hover { color: var(--ink); }
.seg.is-active { background: var(--ink); color: var(--surface); }

.swatches { display: flex; align-items: center; gap: 16px; }
.swatch { display: flex; align-items: center; gap: 9px; font-size: .86rem; color: var(--ink-soft); cursor: pointer; }
.swatch input[type="color"] {
  -webkit-appearance: none; appearance: none;
  width: 34px; height: 34px; padding: 0;
  border: 1px solid var(--line-strong);
  border-radius: 9px; background: none; cursor: pointer;
}
.swatch input[type="color"]::-webkit-color-swatch-wrapper { padding: 3px; }
.swatch input[type="color"]::-webkit-color-swatch { border: none; border-radius: 6px; }
.swatch input[type="color"]::-moz-color-swatch { border: none; border-radius: 6px; }

input[type="range"] {
  -webkit-appearance: none; appearance: none;
  width: 100%; height: 6px; border-radius: 999px;
  background: var(--line-strong); cursor: pointer;
}
input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none; appearance: none;
  width: 18px; height: 18px; border-radius: 50%;
  background: var(--accent); border: 2px solid var(--surface);
  box-shadow: 0 1px 4px rgba(0,0,0,.25);
}
input[type="range"]::-moz-range-thumb {
  width: 18px; height: 18px; border-radius: 50%;
  background: var(--accent); border: 2px solid var(--surface);
}

.warning {
  margin: 18px 0 0;
  font-size: .82rem;
  color: var(--warn-ink);
  background: var(--warn-bg);
  border: 1px solid color-mix(in srgb, var(--warn-ink) 30%, transparent);
  border-radius: var(--radius-sm);
  padding: 10px 12px;
}

/* ---- Stage / preview ------------------------------------------------------ */
.stage__surface {
  position: relative;
  display: grid;
  place-items: center;
  background:
    radial-gradient(circle at 1px 1px, var(--line-strong) 1px, transparent 0);
  background-size: 14px 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  padding: 20px;
  min-height: 300px;
}
.qr-holder {
  line-height: 0;
  border-radius: 8px;
  box-shadow: 0 8px 30px -12px rgba(20,24,34,.45);
  overflow: hidden;
}
#qr-canvas { display: block; width: min(320px, 62vw); height: auto; image-rendering: pixelated; }
.empty-hint {
  position: absolute;
  color: var(--muted);
  font-size: .9rem;
  margin: 0;
}

.readout {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(84px, 1fr));
  gap: 2px;
  margin: 0;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  overflow: hidden;
}
.readout > div {
  background: var(--surface-2);
  padding: 10px 12px;
  display: flex; flex-direction: column; gap: 3px;
}
.readout dt {
  font-size: .68rem; text-transform: uppercase; letter-spacing: .05em;
  color: var(--muted);
}
.readout dd { margin: 0; font-weight: 650; font-size: .95rem; }
.mono { font-family: var(--ff-mono); font-variant-numeric: tabular-nums; }

.actions { display: flex; flex-wrap: wrap; gap: 10px; }
.btn {
  flex: 1 1 auto;
  font: inherit; font-weight: 600; font-size: .9rem;
  color: var(--ink);
  background: var(--surface-2);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-sm);
  padding: 11px 14px;
  cursor: pointer;
  transition: transform .06s, border-color .15s, background .15s, opacity .15s;
}
.btn:hover:not(:disabled) { border-color: var(--muted); }
.btn:active:not(:disabled) { transform: translateY(1px); }
.btn--primary {
  color: var(--accent-ink);
  background: var(--accent);
  border-color: var(--accent);
}
.btn--primary:hover:not(:disabled) { filter: brightness(1.05); }
.btn:disabled { opacity: .45; cursor: not-allowed; }

.toast {
  margin: 0; min-height: 1.2em;
  font-size: .82rem; color: var(--muted);
  text-align: center;
  transition: color .15s;
}
.toast.is-ok { color: var(--accent); }

/* ---- Focus + footer ------------------------------------------------------- */
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.footer {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 clamp(16px, 4vw, 40px) 40px;
  color: var(--muted);
  font-size: .82rem;
  text-align: center;
}

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