:root {
  --bg: #0b0d0b;
  --surface: #121510;
  --surface-raised: #181c16;
  --surface-input: #0d100c;
  --line: #343a2f;
  --line-strong: #4b5442;
  --text: #e8eadf;
  --muted: #929a88;
  --accent: #f3b63f;
  --accent-ink: #181309;
  --cyan: #83cabf;
  --danger: #ff8576;
  --radius: 4px;
  --mono: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  --sans: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }

html {
  height: 100%;
  overflow: hidden;
  scroll-behavior: smooth;
}

body {
  position: fixed;
  inset: 0;
  margin: 0;
  min-width: 320px;
  min-height: 100vh;
  overflow: hidden;
  color: var(--text);
  background:
    linear-gradient(rgba(243, 182, 63, 0.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(243, 182, 63, 0.025) 1px, transparent 1px),
    var(--bg);
  background-size: 32px 32px;
  font-family: var(--sans);
}

button, input, select, textarea { font: inherit; }
button, select, input[type="checkbox"] { cursor: pointer; }
[hidden] { display: none !important; }

.skip-link {
  position: fixed;
  z-index: 100;
  top: 8px;
  left: 8px;
  padding: 10px 14px;
  color: var(--accent-ink);
  background: var(--accent);
  transform: translateY(-150%);
}
.skip-link:focus { transform: translateY(0); }

.page-shell {
  display: grid;
  grid-template-rows: auto minmax(0, 1fr) auto;
  width: min(1920px, 100%);
  height: 100dvh;
  margin: 0 auto;
  padding: 24px;
}

.masthead {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: end;
  gap: 32px;
  padding: 18px 0 24px;
  border-top: 4px solid var(--accent);
  border-bottom: 1px solid var(--line-strong);
}

.eyebrow, .panel-index, .code-stats, .mode-indicator, footer {
  font-family: var(--mono);
  letter-spacing: 0.09em;
  text-transform: uppercase;
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--accent);
  font-size: 0.72rem;
}

h1 {
  margin: 0;
  font-size: clamp(2rem, 4.4vw, 4.8rem);
  font-weight: 800;
  letter-spacing: -0.055em;
  line-height: 0.88;
  text-transform: uppercase;
}
h1 span { color: var(--muted); }

.system-summary {
  display: grid;
  grid-template-columns: repeat(2, minmax(150px, 1fr));
  border: 1px solid var(--line);
  font: 0.67rem/1.4 var(--mono);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
.system-summary span {
  padding: 9px 12px;
  border: 1px solid var(--line);
  color: var(--muted);
}
.system-summary span::before { content: "● "; color: var(--cyan); }

.workspace {
  display: grid;
  grid-template-columns: minmax(390px, 0.72fr) minmax(560px, 1.28fr);
  gap: 16px;
  min-height: 0;
  padding-block: 16px;
  align-items: stretch;
  overflow: hidden;
}

.config-panel, .output-panel, .reference-card {
  border: 1px solid var(--line-strong);
  background: rgba(18, 21, 16, 0.96);
  box-shadow: inset 0 1px rgba(255,255,255,0.025);
}

.config-panel {
  display: flex;
  min-height: 0;
  flex-direction: column;
}

.config-panel form {
  overflow-y: auto;
  overscroll-behavior: contain;
  scrollbar-gutter: stable;
}

.output-panel {
  min-height: 0;
  overflow-y: auto;
  overscroll-behavior: contain;
  scrollbar-gutter: stable;
}

.config-panel form { min-height: 0; }

.panel-heading, .card-heading {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  padding: 16px 18px;
  border-bottom: 1px solid var(--line);
}

.panel-index {
  display: block;
  margin-bottom: 4px;
  color: var(--accent);
  font-size: 0.64rem;
}

h2, h3 { margin: 0; font-size: 1rem; letter-spacing: 0.015em; }
.mode-indicator, .code-stats { color: var(--cyan); font-size: 0.63rem; text-align: right; }

form { padding: 16px 18px 18px; }
fieldset { min-width: 0; margin: 20px 0 0; padding: 0; border: 0; }
fieldset:first-of-type { margin-top: 24px; }
legend {
  width: 100%;
  padding: 0 0 8px;
  border-bottom: 1px solid var(--line);
  color: var(--muted);
  font: 0.68rem var(--mono);
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.preset-row, .field { display: flex; flex-direction: column; gap: 6px; }
.field-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 13px; margin-top: 13px; }
.field-wide { grid-column: 1 / -1; }
label { color: #cbd0c3; font-size: 0.76rem; font-weight: 650; }
.unit { color: var(--muted); font-family: var(--mono); font-size: 0.65rem; font-weight: 400; }

input[type="text"], input[type="number"], select {
  width: 100%;
  min-height: 42px;
  padding: 9px 11px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  outline: 0;
  color: var(--text);
  background: var(--surface-input);
  font-family: var(--mono);
  font-size: 0.78rem;
}
select { appearance: auto; }
input:hover, select:hover { border-color: #69735e; }
input:focus-visible, select:focus-visible, button:focus-visible, textarea:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}
input[aria-invalid="true"] { border-color: var(--danger); }
.field-error { min-height: 0.8rem; color: var(--danger); font-size: 0.67rem; line-height: 1.25; }
.field-error:empty { display: none; }
.field-hint { margin: 6px 0 0; color: var(--muted); font-size: 0.68rem; line-height: 1.45; }

.toggle-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 8px; margin-top: 12px; }
.toggle {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  align-items: center;
  min-height: 42px;
  padding: 8px 10px;
  border: 1px solid var(--line);
  background: var(--surface-input);
}
.toggle input { position: absolute; opacity: 0; pointer-events: none; }
.toggle > span[aria-hidden] {
  position: relative;
  width: 27px;
  height: 15px;
  border: 1px solid var(--line-strong);
  border-radius: 20px;
  background: #242820;
}
.toggle > span[aria-hidden]::after {
  content: "";
  position: absolute;
  top: 2px;
  left: 2px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--muted);
  transition: transform 120ms linear, background 120ms linear;
}
.toggle input:checked + span { border-color: #a77c27; background: #4b3919; }
.toggle input:checked + span::after { background: var(--accent); transform: translateX(12px); }
.toggle input:focus-visible + span { outline: 2px solid var(--accent); outline-offset: 3px; }
.toggle > span:last-child { font-size: 0.71rem; }
.output-note { margin-top: 10px; }

.form-actions, .output-toolbar { display: flex; align-items: center; gap: 8px; }
.form-actions { margin-top: 22px; padding-top: 16px; border-top: 1px solid var(--line); }
.button {
  min-height: 40px;
  padding: 9px 14px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  color: var(--text);
  background: var(--surface-raised);
  font: 700 0.69rem var(--mono);
  letter-spacing: 0.035em;
  text-transform: uppercase;
}
.button:hover { border-color: var(--accent); color: var(--accent); }
.button:active { transform: translateY(1px); }
.button-primary { border-color: var(--accent); color: var(--accent-ink); background: var(--accent); }
.button-primary:hover { color: var(--accent-ink); background: #ffd06c; }
.button-quiet { margin-left: auto; color: var(--muted); background: transparent; }
.button-secondary { min-height: 34px; padding: 7px 11px; }

.output-toolbar { min-height: 52px; padding: 9px 14px; border-bottom: 1px solid var(--line); }
.status { margin-left: auto; color: var(--cyan); font: 0.68rem var(--mono); }

.code-editor {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  height: min(68vh, 740px);
  min-height: 520px;
  overflow: hidden;
  background: #090b09;
}
.line-numbers, #sfml-output {
  margin: 0;
  padding-block: 16px;
  border: 0;
  border-radius: 0;
  font: 0.75rem/1.65 var(--mono);
  tab-size: 4;
}
.line-numbers {
  min-width: 54px;
  padding-inline: 10px;
  overflow: hidden;
  border-right: 1px solid var(--line);
  color: #5e6658;
  background: #0d100c;
  text-align: right;
  user-select: none;
}
#sfml-output {
  width: 100%;
  height: 100%;
  resize: none;
  padding-inline: 16px;
  outline-offset: -2px;
  color: #dce8cf;
  background: transparent;
  white-space: pre;
}

.reference-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; padding-top: 12px; }
.reference-card { min-width: 0; }
.reference-card .card-heading { padding: 13px 15px; }
.reference-card pre {
  min-height: 260px;
  max-height: 430px;
  margin: 0;
  padding: 15px;
  overflow: auto;
  color: #bec7b3;
  font: 0.7rem/1.55 var(--mono);
  white-space: pre;
}

footer {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  padding: 16px 2px 4px;
  border-top: 1px solid var(--line-strong);
  color: var(--muted);
  font-size: 0.61rem;
}
footer p { margin: 0; }
footer p:last-child { color: var(--cyan); text-align: right; }

@media (max-width: 1120px) {
  .workspace {
    grid-template-columns: 1fr;
    align-content: start;
    overflow-y: auto;
    overscroll-behavior: contain;
  }
  .config-panel form,
  .output-panel { overflow: visible; }
  .code-editor { height: 70vh; }
}

@media (max-width: 700px) {
  .page-shell { padding: 12px; }
  .masthead { grid-template-columns: 1fr; gap: 20px; }
  .system-summary { grid-template-columns: 1fr 1fr; }
  .field-grid, .toggle-grid, .reference-grid { grid-template-columns: 1fr; }
  .field-wide { grid-column: auto; }
  .output-toolbar { align-items: stretch; flex-wrap: wrap; }
  .output-toolbar .button { flex: 1; }
  .status { width: 100%; margin: 4px 0 0; }
  .code-editor { min-height: 460px; height: 64vh; }
  .reference-card pre { min-height: 220px; }
  footer { flex-direction: column; }
  footer p:last-child { text-align: left; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; transition: none !important; }
}