/* ===== 1. Custom properties ===== */
:root {
  --bg: #f7f9f8;
  --surface: #ffffff;
  --ink: #16211c;
  --ink-soft: #4b5a52;
  --border: #e2e8e4;
  --accent: #1f8a5c;
  --accent-dark: #146643;
  --accent-soft: #e5f5ec;

  --cat-bajo: #2f8fd6;
  --cat-normal: #1f8a5c;
  --cat-sobre: #e08a1f;
  --cat-obesidad: #d64545;

  --sans: 'Inter', system-ui, sans-serif;
  --display: 'Manrope', system-ui, sans-serif;

  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --radius: 16px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1512;
    --surface: #161f1a;
    --ink: #eef3f0;
    --ink-soft: #a9b8b0;
    --border: #263229;
    --accent-soft: #17281f;
  }
}

/* ===== 2. Reset ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; }
html { -webkit-text-size-adjust: 100%; tab-size: 2; scroll-behavior: smooth; }
body {
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: clip;
}
img, svg { display: block; max-width: 100%; }
button { font: inherit; color: inherit; cursor: pointer; border: 0; background: none; }
a { color: inherit; text-decoration: none; }
p { text-wrap: pretty; }
h1, h2, h3, h4 { font-family: var(--display); text-wrap: balance; line-height: 1.1; letter-spacing: -0.01em; color: var(--ink); }
::selection { background: var(--accent-soft); color: var(--accent-dark); }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 4px; }

.skip-link {
  position: fixed; top: -100px; left: 1rem;
  padding: .6rem 1rem; background: var(--surface); color: var(--ink);
  z-index: 9999; border-radius: 8px; font-weight: 600; box-shadow: 0 4px 16px rgba(0,0,0,.15);
}
.skip-link:focus { top: 1rem; }

.wrap { max-width: 760px; margin: 0 auto; padding: 0 1.25rem; }

/* ===== 3. Header / Footer ===== */
.site-header { padding: 1.1rem 0; border-bottom: 1px solid var(--border); }
.header-inner { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: .4rem; }
.logo { font-family: var(--display); font-weight: 800; font-size: 1.3rem; }
.logo span { color: var(--accent); }
.header-tag { font-size: .82rem; color: var(--ink-soft); }

.site-footer { border-top: 1px solid var(--border); padding: 1.5rem 0 2.5rem; margin-top: 2.5rem; color: var(--ink-soft); font-size: .88rem; }
.footer-inner { display: flex; flex-wrap: wrap; gap: .8rem; align-items: center; justify-content: space-between; }
.footer-links { display: flex; gap: 1rem; }
.footer-links a:hover { color: var(--accent); }

/* ===== 4. Hero + tool card ===== */
.hero { padding: 2.2rem 0 1.4rem; text-align: center; }
.hero h1 { font-size: clamp(1.7rem, 4.5vw, 2.4rem); }
.subtitle { color: var(--ink-soft); margin-top: .6rem; font-size: 1.02rem; max-width: 560px; margin-inline: auto; }

.tool-card {
  margin-top: 1.6rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.6rem;
  text-align: left;
  box-shadow: 0 1px 3px rgba(20,30,25,.04);
}

.unit-switch { display: flex; gap: .4rem; background: var(--bg); border: 1px solid var(--border); border-radius: 999px; padding: .3rem; margin-bottom: 1.2rem; width: fit-content; }
.unit-btn { padding: .5rem 1.1rem; border-radius: 999px; font-weight: 600; font-size: .9rem; color: var(--ink-soft); transition: background .2s var(--ease-out), color .2s var(--ease-out); }
.unit-btn.is-active { background: var(--accent); color: #fff; }

.field-group { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
.field-group.is-hidden { display: none; }
.field { display: flex; flex-direction: column; gap: .4rem; }
.field label { font-size: .85rem; font-weight: 600; color: var(--ink-soft); }
.field input {
  font: inherit; font-size: 1.05rem; padding: .75rem .9rem;
  border: 1.5px solid var(--border); border-radius: 10px; background: var(--bg); color: var(--ink);
  transition: border-color .15s var(--ease-out);
}
.field input:focus { border-color: var(--accent); outline: none; }

.btn-calcular {
  width: 100%; margin-top: 1.3rem; padding: .95rem;
  background: var(--accent); color: #fff; font-weight: 700; font-size: 1.02rem;
  border-radius: 12px; transition: background .15s var(--ease-out), transform .1s var(--ease-out);
}
.btn-calcular:hover { background: var(--accent-dark); }
.btn-calcular:active { transform: scale(.98); }

.error-msg { color: var(--cat-obesidad); font-size: .88rem; margin-top: .7rem; font-weight: 600; }
.error-msg:not([hidden]) { display: block; }

.resultado { margin-top: 1.4rem; padding-top: 1.4rem; border-top: 1px dashed var(--border); text-align: center; animation: fadeIn .3s var(--ease-out); }
.resultado-numero { display: flex; flex-direction: column; align-items: center; gap: .3rem; }
.resultado-valor { font-family: var(--display); font-weight: 800; font-size: clamp(2.6rem, 8vw, 3.4rem); line-height: 1; color: var(--accent); }
.resultado-cat { font-weight: 700; font-size: 1.05rem; padding: .3rem .9rem; border-radius: 999px; background: var(--accent-soft); color: var(--accent-dark); }
.resultado[data-cat="bajo"] .resultado-valor, .resultado[data-cat="bajo"] .resultado-cat { color: var(--cat-bajo); }
.resultado[data-cat="bajo"] .resultado-cat { background: color-mix(in srgb, var(--cat-bajo) 14%, transparent); }
.resultado[data-cat="normal"] .resultado-valor, .resultado[data-cat="normal"] .resultado-cat { color: var(--cat-normal); }
.resultado[data-cat="normal"] .resultado-cat { background: color-mix(in srgb, var(--cat-normal) 14%, transparent); }
.resultado[data-cat="sobre"] .resultado-valor, .resultado[data-cat="sobre"] .resultado-cat { color: var(--cat-sobre); }
.resultado[data-cat="sobre"] .resultado-cat { background: color-mix(in srgb, var(--cat-sobre) 14%, transparent); }
.resultado[data-cat="obesidad"] .resultado-valor, .resultado[data-cat="obesidad"] .resultado-cat { color: var(--cat-obesidad); }
.resultado[data-cat="obesidad"] .resultado-cat { background: color-mix(in srgb, var(--cat-obesidad) 14%, transparent); }
.resultado-nota { color: var(--ink-soft); font-size: .82rem; margin-top: .8rem; }
.btn-reset { margin-top: .9rem; font-weight: 600; color: var(--accent); text-decoration: underline; font-size: .9rem; }

@keyframes fadeIn { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: translateY(0); } }

.privacy-badge { margin-top: 1rem; font-size: .84rem; color: var(--ink-soft); }

/* ===== 5. Ad slots ===== */
.ad-slot {
  display: flex; align-items: center; justify-content: center;
  min-height: 90px; border: 1px dashed var(--border); border-radius: 10px;
  color: var(--ink-soft); font-size: .78rem; letter-spacing: .08em; text-transform: uppercase; font-weight: 700;
  background: repeating-linear-gradient(45deg, var(--surface), var(--surface) 10px, var(--bg) 10px, var(--bg) 20px);
}
.ad-leaderboard { max-width: 760px; margin: 2rem auto; margin-inline: auto; }
.ad-leaderboard, .ad-in-content { margin-left: 1.25rem; margin-right: 1.25rem; }
@media (min-width: 800px) { .ad-leaderboard, .ad-in-content { margin-left: auto; margin-right: auto; max-width: 760px; } }
.ad-in-content { margin-top: 1.6rem; margin-bottom: 1.6rem; min-height: 250px; }

.ad-dialog {
  border: none; border-radius: var(--radius); padding: 1.4rem; max-width: 380px; width: calc(100% - 2rem);
  box-shadow: 0 20px 60px rgba(0,0,0,.25); background: var(--surface); color: var(--ink);
}
.ad-dialog::backdrop { background: rgba(15, 21, 18, .55); }
.ad-dialog-close { position: absolute; top: .6rem; right: .8rem; font-size: 1.4rem; line-height: 1; color: var(--ink-soft); }
.ad-dialog .ad-slot { min-height: 250px; margin-top: .6rem; }
.ad-dialog-btn { width: 100%; margin-top: 1rem; padding: .7rem; background: var(--bg); border: 1px solid var(--border); border-radius: 10px; font-weight: 600; }

.ad-corner {
  position: fixed; bottom: 1rem; right: 1rem; z-index: 500;
  background: var(--surface); border: 1px solid var(--border); border-radius: 12px; padding: .5rem;
  box-shadow: 0 8px 24px rgba(0,0,0,.15); animation: fadeIn .3s var(--ease-out);
}
.ad-corner-close { position: absolute; top: -.5rem; right: -.5rem; width: 22px; height: 22px; border-radius: 50%; background: var(--ink); color: var(--surface); font-size: .9rem; line-height: 1; display: flex; align-items: center; justify-content: center; }
.ad-corner-slot { width: 220px; height: 90px; min-height: unset; }

/* ===== 6. Content sections ===== */
.contenido { padding: 2rem 0; }
.contenido h2 { font-size: clamp(1.4rem, 3.5vw, 1.8rem); margin-bottom: .9rem; }
.contenido h3 { font-size: 1.15rem; margin: 1.3rem 0 .6rem; }
.contenido p { color: var(--ink-soft); }
.contenido p + p { margin-top: .8rem; }

.explicacion-visual { display: grid; gap: 1.2rem; margin-top: .8rem; }
.explicacion-formula {
  background: var(--accent-soft); border-radius: var(--radius); padding: 1.3rem;
  text-align: center; border: 1px solid color-mix(in srgb, var(--accent) 25%, transparent);
}
.formula-titulo { font-size: .78rem; text-transform: uppercase; letter-spacing: .08em; font-weight: 700; color: var(--accent-dark); }
.formula { font-family: var(--display); font-weight: 800; font-size: 1.4rem; color: var(--accent-dark); margin: .4rem 0; }
.formula-desc { color: var(--accent-dark); opacity: .85; font-size: .9rem; }

.tabla-wrap { overflow-x: auto; margin-top: .6rem; border-radius: 12px; border: 1px solid var(--border); }
.tabla-imc { width: 100%; border-collapse: collapse; background: var(--surface); }
.tabla-imc th, .tabla-imc td { padding: .8rem 1rem; text-align: left; border-bottom: 1px solid var(--border); font-size: .95rem; }
.tabla-imc thead th { background: var(--bg); font-size: .78rem; text-transform: uppercase; letter-spacing: .05em; color: var(--ink-soft); }
.tabla-imc tbody tr:last-child td { border-bottom: none; }
.tabla-imc tr[data-cat="bajo"] td:first-child { border-left: 4px solid var(--cat-bajo); }
.tabla-imc tr[data-cat="normal"] td:first-child { border-left: 4px solid var(--cat-normal); }
.tabla-imc tr[data-cat="sobre"] td:first-child { border-left: 4px solid var(--cat-sobre); }
.tabla-imc tr[data-cat="obesidad"] td:first-child { border-left: 4px solid var(--cat-obesidad); }
.tabla-imc tr.is-user-row { background: var(--accent-soft); font-weight: 700; }

.limitaciones-grid { display: grid; gap: 1rem; margin-top: 1rem; }
.limitacion-card { background: var(--surface); border: 1px solid var(--border); border-radius: 12px; padding: 1.1rem; }
.limitacion-card h3 { margin-top: 0; font-size: 1.02rem; color: var(--accent-dark); }
.limitacion-card p { font-size: .92rem; }

.lista-alimentacion { list-style: none; display: grid; gap: .8rem; margin-top: .8rem; }
.lista-alimentacion li { background: var(--surface); border: 1px solid var(--border); border-radius: 10px; padding: .9rem 1rem; font-size: .95rem; color: var(--ink-soft); }
.lista-alimentacion li strong { color: var(--ink); }

.faq details { border-bottom: 1px solid var(--border); padding: .9rem 0; }
.faq summary { font-weight: 700; cursor: pointer; list-style: none; display: flex; justify-content: space-between; align-items: center; gap: 1rem; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; font-size: 1.3rem; color: var(--accent); flex-shrink: 0; }
.faq details[open] summary::after { content: "–"; }
.faq details p { margin-top: .6rem; font-size: .95rem; }

/* ===== 7. Breakpoints ===== */
@media (min-width: 540px) {
  .limitaciones-grid { grid-template-columns: repeat(3, 1fr); }
}
@media (min-width: 720px) {
  .explicacion-visual { grid-template-columns: 260px 1fr; align-items: center; }
}

/* ===== 8. Reduced motion ===== */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; }
}