:root {
  --accent: #17597f;
  --accent-dark: #0e3b56;
  --accent-soft: #e6f0f6;
  --bg: #f1f4f7;
  --card: #fff;
  --border: #d9e0e7;
  --border-strong: #b9c4cf;
  --text: #18222c;
  --muted: #5b6875;
  --warn-bg: #fff6dd;
  --warn: #7a5600;
  --danger: #b3261e;
  --radius: 12px;
  --shadow: 0 1px 2px rgba(16, 32, 48, .05), 0 4px 14px rgba(16, 32, 48, .06);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 15px/1.5 system-ui, "Segoe UI", Roboto, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}

/* Encabezado */

header {
  position: sticky;
  top: 0;
  z-index: 5;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 24px;
  padding: 12px 28px;
  background: rgba(255, 255, 255, .92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}

.brand { display: flex; align-items: center; gap: 12px; }
.logo { width: 36px; height: 36px; padding: 5px; border-radius: 9px; background: var(--accent-soft); color: var(--accent); }
h1 { margin: 0; font-size: 18px; line-height: 1.25; letter-spacing: -.01em; }
.tagline { margin: 0; font-size: 13px; color: var(--muted); }

.examples { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; font-size: 13px; color: var(--muted); }

h2 { margin: 0 0 12px; font-size: 13px; font-weight: 650; letter-spacing: .04em; text-transform: uppercase; color: var(--muted); }
h2.section { margin: 8px 2px -4px; }

/* Estructura */

main {
  display: grid;
  grid-template-columns: minmax(360px, 460px) minmax(0, 1fr);
  gap: 22px;
  max-width: 1680px;
  margin: 0 auto;
  padding: 22px 28px 32px;
  align-items: start;
}

.editor, .output { display: grid; grid-template-columns: minmax(0, 1fr); gap: 14px; min-width: 0; }

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 16px;
}

/* Formulario */

.card > label, .pair { margin-bottom: 12px; }
label { display: block; font-size: 12.5px; font-weight: 550; color: var(--muted); }
.pair { display: grid; grid-template-columns: 1fr 90px; gap: 10px; }

input:not([type="checkbox"]), select, textarea {
  display: block;
  width: 100%;
  margin-top: 4px;
  padding: 8px 10px;
  border: 1px solid var(--border-strong);
  border-radius: 8px;
  background: #fff;
  color: var(--text);
  font: inherit;
  font-size: 14px;
  font-weight: 400;
  transition: border-color .12s, box-shadow .12s;
}
input::placeholder, textarea::placeholder { color: #9aa6b2; }
input:not([type="checkbox"]):hover, select:hover, textarea:hover { border-color: #8fa0b0; }
input:not([type="checkbox"]):focus, select:focus, textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(23, 89, 127, .18);
}
textarea { resize: vertical; min-height: 56px; font-size: 13px; line-height: 1.4; }

.check { display: flex; align-items: center; gap: 8px; color: var(--text); font-size: 14px; font-weight: 400; cursor: pointer; }
.check input { width: 16px; height: 16px; accent-color: var(--accent); }
.card .check { margin-bottom: 6px; }

.subhead { margin: 14px 0 6px; font-size: 12.5px; font-weight: 550; color: var(--muted); }
.col-row { display: grid; grid-template-columns: 1fr 1fr 30px; gap: 6px; align-items: center; margin-bottom: 6px; }
.col-row input, .row input { margin-top: 0; }

/* Alternativas */

.card.alt { border-left: 4px solid var(--accent); margin-bottom: 14px; }
#alternatives .card.alt:last-child { margin-bottom: 0; }
.alt-head { display: flex; align-items: flex-end; gap: 10px; margin-bottom: 12px; }
.alt-head input:not([type="checkbox"]) { font-weight: 600; }
.grow { flex: 1; }
.sym { width: 76px; }
.detail { margin-bottom: 12px; }

.row {
  display: grid;
  grid-template-columns: 1fr 92px 1.3fr 30px;
  gap: 6px;
  align-items: center;
  margin-bottom: 6px;
}
.row.head { font-size: 12px; font-weight: 550; color: var(--muted); margin-bottom: 3px; }

.cells {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(110px, 1fr));
  gap: 6px;
  margin: 2px 36px 14px 0;
  padding: 8px 0 2px 10px;
  border-left: 2px solid var(--accent-soft);
}
.cells label { font-size: 12px; }

/* Botones */

button {
  padding: 8px 14px;
  border: 1px solid var(--accent);
  border-radius: 8px;
  background: var(--accent);
  color: #fff;
  font: inherit;
  font-weight: 550;
  cursor: pointer;
  transition: background .12s, border-color .12s, color .12s;
}
button:hover { background: var(--accent-dark); border-color: var(--accent-dark); }
button:focus-visible { outline: 3px solid rgba(23, 89, 127, .35); outline-offset: 2px; }

button.secondary { background: #fff; color: var(--accent); border-color: var(--border-strong); }
button.secondary:hover { background: var(--accent-soft); border-color: var(--accent); }
button.dashed { border-style: dashed; padding: 11px; }

button.chip {
  padding: 5px 12px;
  border-radius: 999px;
  border-color: var(--border-strong);
  background: #fff;
  color: var(--accent);
  font-size: 13px;
}
button.chip:hover { background: var(--accent-soft); border-color: var(--accent); }

button.link { border: 0; background: none; color: var(--accent); padding: 4px 2px; font-size: 13.5px; }
button.link:hover { background: none; text-decoration: underline; }

button.icon {
  width: 30px;
  height: 30px;
  padding: 0;
  border: 0;
  border-radius: 8px;
  background: none;
  color: #8a96a3;
  font-weight: 400;
}
button.icon:hover { background: #fdeceb; color: var(--danger); }

.hint {
  margin: 0;
  padding: 12px 14px;
  border-radius: var(--radius);
  background: var(--accent-soft);
  color: #2f4a5c;
  font-size: 13px;
}
code { background: rgba(255, 255, 255, .8); padding: 1px 5px; border-radius: 4px; font: 12px/1.4 ui-monospace, Consolas, monospace; }

/* Resultado */

.toolbar { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; margin-bottom: 14px; }
.toolbar h2 { margin: 0; }
#status { flex: 1; min-width: 0; font-size: 13px; color: var(--accent); text-align: right; }

#warnings {
  margin: 0 0 14px;
  padding: 10px 14px 10px 30px;
  background: var(--warn-bg);
  border: 1px solid #f0dca0;
  color: var(--warn);
  border-radius: 8px;
  font-size: 13px;
}

#preview {
  overflow-x: auto;
  padding: 10px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #fff;
}
#preview svg { display: block; max-width: 100%; height: auto; margin: 0 auto; }

#resolution { font-size: 14.5px; font-variant-numeric: tabular-nums; }
#resolution p { margin: 0 0 12px; }
#resolution .conclusion {
  margin: 14px 0 0;
  padding: 12px 14px;
  border-radius: 8px;
  background: #e9f6e6;
  border: 1px solid #bfe0b8;
  color: #1f4d1a;
}

footer { padding: 0 28px 24px; text-align: center; font-size: 12px; color: #93a0ad; }

@media (min-width: 1000px) {
  .output { position: sticky; top: 84px; max-height: calc(100vh - 100px); overflow-y: auto; padding: 0 4px 4px 0; }
}

@media (max-width: 999px) {
  main { grid-template-columns: minmax(0, 1fr); padding: 16px; }
  header { position: static; padding: 12px 16px; }
  .tagline { display: none; }
  #status { flex-basis: 100%; text-align: left; order: 5; }
}

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