:root {
  --bg: #0d0f13;
  --panel: #14181f;
  --panel-2: #1b2029;
  --line: #262d38;
  --text: #e6e9ef;
  --muted: #8b95a7;
  --accent: #5b9dff;
  --accent-ink: #061225;
  --ok: #4ade80;
  --warn: #fbbf24;
  --err: #f87171;
  --radius: 10px;
  --mono: ui-monospace, "SF Mono", "Cascadia Mono", "JetBrains Mono", Menlo, Consolas, monospace;
}

@media (prefers-color-scheme: light) {
  :root {
    --bg: #f4f6fa;
    --panel: #ffffff;
    --panel-2: #f0f3f8;
    --line: #dfe4ec;
    --text: #161a21;
    --muted: #667085;
    --accent: #2563eb;
    --accent-ink: #ffffff;
    --ok: #16a34a;
    --warn: #b45309;
    --err: #dc2626;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 15px/1.55 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  -webkit-font-smoothing: antialiased;
}

.wrap {
  max-width: 860px;
  margin: 0 auto;
  padding: 48px 20px 64px;
}

/* ---------------------------------------------------------------- header */

.head { margin-bottom: 26px; }

.head h1 {
  margin: 0 0 6px;
  font-size: 30px;
  font-weight: 650;
  letter-spacing: -0.02em;
}

.head .arrow { color: var(--accent); }

.sub {
  margin: 0;
  color: var(--muted);
  font-size: 14.5px;
}

/* ----------------------------------------------------------------- cards */

.card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px;
}

.card + .card, .result { margin-top: 16px; }

.label-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin-bottom: 8px;
}

.label-row label {
  font-size: 13px;
  font-weight: 550;
}

.hint {
  font-size: 12.5px;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
}

textarea {
  width: 100%;
  min-height: 190px;
  resize: vertical;
  padding: 12px 14px;
  background: var(--panel-2);
  color: var(--text);
  border: 1px solid var(--line);
  border-radius: 8px;
  font: 13px/1.6 var(--mono);
  word-break: break-all;
}

textarea::placeholder { color: var(--muted); opacity: 0.75; }

textarea:focus-visible,
input[type="text"]:focus-visible,
.btn:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* --------------------------------------------------------------- buttons */

.controls {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
  margin-top: 14px;
}

.spacer { flex: 1 1 auto; }

.btn {
  padding: 9px 16px;
  border-radius: 8px;
  border: 1px solid var(--line);
  background: var(--panel-2);
  color: var(--text);
  font: inherit;
  font-size: 14px;
  font-weight: 550;
  cursor: pointer;
  transition: background 0.12s, border-color 0.12s, opacity 0.12s;
}

.btn:hover:not(:disabled) { border-color: var(--muted); }

.btn.primary {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--accent-ink);
}

.btn.primary:hover:not(:disabled) { filter: brightness(1.08); }

.btn:disabled { opacity: 0.45; cursor: not-allowed; }

.kbd-hint { font-size: 12px; color: var(--muted); }

kbd {
  font: 11px var(--mono);
  padding: 2px 5px;
  border: 1px solid var(--line);
  border-bottom-width: 2px;
  border-radius: 4px;
  background: var(--panel-2);
}

/* -------------------------------------------------------------- messages */

.message {
  margin-top: 16px;
  padding: 12px 14px;
  border-radius: 8px;
  border: 1px solid var(--line);
  background: var(--panel);
  font-size: 14px;
  border-left-width: 3px;
}

.message.error { border-left-color: var(--err); color: var(--err); }
.message.warn  { border-left-color: var(--warn); color: var(--warn); }
.message.ok    { border-left-color: var(--ok); color: var(--ok); }

.message code {
  font: 12.5px var(--mono);
  background: var(--panel-2);
  padding: 1px 5px;
  border-radius: 4px;
}

/* ---------------------------------------------------------------- result */

.meta {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 4px;
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 11px;
  border-radius: 999px;
  background: var(--panel-2);
  border: 1px solid var(--line);
  font-size: 12.5px;
  color: var(--muted);
}

.chip b {
  color: var(--text);
  font-weight: 550;
  font-variant-numeric: tabular-nums;
}

.chip.good  { border-color: color-mix(in srgb, var(--ok) 45%, var(--line)); }
.chip.alert { border-color: color-mix(in srgb, var(--warn) 45%, var(--line)); }
.chip.alert b { color: var(--warn); }

.namefield {
  display: flex;
  align-items: center;
  gap: 9px;
}

.namefield label { font-size: 13px; color: var(--muted); }

.namefield input {
  width: 220px;
  padding: 8px 11px;
  background: var(--panel-2);
  color: var(--text);
  border: 1px solid var(--line);
  border-radius: 8px;
  font: 13px var(--mono);
}

.preview-shell {
  position: relative;
  margin-top: 16px;
  border: 1px solid var(--line);
  border-radius: 8px;
  overflow: hidden;
  background: var(--panel-2);
  height: 560px;
}

.preview-shell iframe {
  position: relative;
  width: 100%;
  height: 100%;
  border: 0;
  display: block;
}

.preview-fallback {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0;
  padding: 20px;
  text-align: center;
  color: var(--muted);
  font-size: 14px;
}

/* ---------------------------------------------------------------- footer */

.foot {
  margin-top: 28px;
  text-align: center;
  font-size: 12.5px;
  color: var(--muted);
}

.foot code {
  font: 12px var(--mono);
  color: var(--text);
}

@media (max-width: 620px) {
  .wrap { padding: 28px 14px 48px; }
  .head h1 { font-size: 24px; }
  .namefield input { width: 100%; }
  .namefield { flex: 1 1 100%; }
  .preview-shell { height: 62vh; }
}