/* ==========================================================================
   CalculaObra — hoja de estilos compartida del portal
   Secciones: 1 tokens · 2 base · 3 layout/cabecera · 4 tarjeta herramienta
   5 resultado · 6 contenido · 7 anuncios · 8 tarjetas/hubs · 9 pie · 10 util
   ========================================================================== */

/* 1. Tokens ---------------------------------------------------------------- */
:root {
  --bg: #f6f7f9;
  --surface: #ffffff;
  --surface-2: #f0f3f6;
  --ink: #142030;
  --ink-2: #4a5a6c;
  --line: #dde3ea;
  --accent: #0b6bcb;          /* azul instalaciones */
  --accent-ink: #ffffff;
  --accent-soft: #e6f0fb;
  --brand: #e8590c;           /* naranja obra (marca) */
  --ok: #157f3b;
  --ok-soft: #e7f6ec;
  --warn: #9a5b00;
  --warn-soft: #fff4e0;
  --err: #b42318;
  --err-soft: #fdecea;
  --radius: 14px;
  --radius-sm: 9px;
  --shadow: 0 1px 2px rgba(20, 32, 48, .06), 0 8px 24px rgba(20, 32, 48, .06);
  --font: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --maxw: 1080px;
  --gutter: 16px;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0e141b;
    --surface: #151d27;
    --surface-2: #1b2531;
    --ink: #e7edf3;
    --ink-2: #a3b1c0;
    --line: #2a3644;
    --accent: #4da3ff;
    --accent-ink: #06121f;
    --accent-soft: #14283f;
    --brand: #ff8a4c;
    --ok: #4cc77a;
    --ok-soft: #12291c;
    --warn: #f0b354;
    --warn-soft: #2c2210;
    --err: #ff8b80;
    --err-soft: #331614;
    --shadow: 0 1px 2px rgba(0, 0, 0, .3), 0 8px 24px rgba(0, 0, 0, .25);
    color-scheme: dark;
  }
}

/* 2. Base ------------------------------------------------------------------ */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.6 var(--font);
  overflow-wrap: break-word;
  /* Pie de página siempre abajo, aunque la página tenga poco contenido */
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
}
body > main { flex: 1 0 auto; }
body > .site-header, body > .site-footer { flex-shrink: 0; }
[hidden] { display: none !important; }
img, svg { max-width: 100%; display: block; }
a { color: var(--accent); text-underline-offset: 2px; }
a:hover { text-decoration-thickness: 2px; }
h1, h2, h3 { line-height: 1.2; letter-spacing: -.01em; margin: 0 0 .5em; }
h1 { font-size: clamp(1.6rem, 1.2rem + 2vw, 2.4rem); font-weight: 800; }
h2 { font-size: clamp(1.3rem, 1.1rem + .9vw, 1.65rem); margin-top: 2rem; }
h3 { font-size: 1.1rem; margin-top: 1.4rem; }
p, ul, ol { margin: 0 0 1em; }
:focus-visible { outline: 3px solid var(--accent); outline-offset: 2px; border-radius: 4px; }
.skip { position: absolute; left: -999px; top: 0; background: var(--surface); padding: 8px 12px; z-index: 10; }
.skip:focus { left: 8px; }

/* 3. Layout / cabecera ----------------------------------------------------- */
.wrap { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 var(--gutter); }
.site-header { background: var(--surface); border-bottom: 1px solid var(--line); }
.site-header .wrap { display: flex; align-items: center; justify-content: space-between; gap: 12px; min-height: 58px; }
.logo { display: flex; align-items: center; gap: 8px; font-weight: 800; font-size: 1.12rem; color: var(--ink); text-decoration: none; }
.logo svg { width: 28px; height: 28px; }
.logo b { color: var(--brand); }
.nav-toggle { display: none; background: none; border: 1px solid var(--line); border-radius: var(--radius-sm); padding: 6px 10px; color: var(--ink); font: inherit; cursor: pointer; }
.site-nav ul { list-style: none; margin: 0; padding: 0; display: flex; gap: 4px; }
.site-nav a { display: block; padding: 8px 12px; border-radius: var(--radius-sm); color: var(--ink-2); text-decoration: none; font-weight: 600; font-size: .95rem; }
.site-nav a:hover, .site-nav a[aria-current="page"] { background: var(--surface-2); color: var(--ink); }
@media (max-width: 720px) {
  .js .nav-toggle { display: block; }
  .js .site-nav { display: none; position: absolute; left: 0; right: 0; top: 58px; background: var(--surface); border-bottom: 1px solid var(--line); padding: 8px var(--gutter) 12px; z-index: 5; }
  .js .site-nav.open { display: block; }
  .site-nav ul { flex-direction: column; }
  .site-header { position: relative; }
  html:not(.js) .site-nav ul { flex-direction: row; flex-wrap: wrap; }
  html:not(.js) .site-header .wrap { flex-wrap: wrap; padding-bottom: 6px; }
}

.breadcrumbs { font-size: .88rem; color: var(--ink-2); margin: 14px 0 6px; }
.breadcrumbs ol { list-style: none; padding: 0; margin: 0; display: flex; flex-wrap: wrap; gap: 4px; }
.breadcrumbs li + li::before { content: "›"; margin-right: 4px; color: var(--ink-2); }
.breadcrumbs a { color: var(--ink-2); }

.page-head { margin: 6px 0 16px; }
.page-head .lead { font-size: clamp(.98rem, .9rem + .4vw, 1.05rem); color: var(--ink-2); font-size: 1.05rem; margin: 0; max-width: 62ch; }

/* 4. Tarjeta de la herramienta --------------------------------------------- */
.tool-layout { display: grid; grid-template-columns: minmax(0, 1.1fr) minmax(0, .9fr); gap: 18px; align-items: start; }
@media (max-width: 860px) { .tool-layout { grid-template-columns: minmax(0, 1fr); } }
.tool-card, .result-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 20px;
}
@media (max-width: 480px) { .tool-card, .result-card { padding: 16px; } }
.tool-card fieldset { border: 0; padding: 0; margin: 0 0 14px; min-width: 0; }
.tool-card legend { font-weight: 700; margin-bottom: 8px; padding: 0; }
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
@media (max-width: 420px) { .grid-2 { grid-template-columns: 1fr; } }
.field { margin-bottom: 12px; }
.field label, .field .label { display: block; font-weight: 600; font-size: .95rem; margin-bottom: 5px; }
.field .hint { display: block; font-size: .83rem; color: var(--ink-2); margin-top: 4px; }
.input-unit { position: relative; display: flex; align-items: stretch; }
.input-unit input { padding-right: 52px; }
.input-unit .unit { position: absolute; right: 12px; top: 50%; transform: translateY(-50%); color: var(--ink-2); font-size: .9rem; pointer-events: none; }
input[type="text"], input[type="number"], select {
  width: 100%;
  font: inherit;
  font-size: 1rem;           /* ≥16px: evita zoom en iOS */
  color: var(--ink);
  background: var(--surface);
  border: 1.5px solid var(--line);
  border-radius: var(--radius-sm);
  padding: 11px 12px;
  min-height: 46px;
}
input:focus, select:focus { border-color: var(--accent); outline: none; box-shadow: 0 0 0 3px var(--accent-soft); }
.field.has-error input, .field.has-error select { border-color: var(--err); }
.field .error { display: none; color: var(--err); font-size: .85rem; margin-top: 4px; font-weight: 600; }
.field.has-error .error { display: block; }

.seg { display: grid; grid-template-columns: repeat(3, 1fr); gap: 6px; }
.seg-4 { grid-template-columns: repeat(4, 1fr); }
.seg-2 { grid-template-columns: repeat(2, 1fr); }
@media (max-width: 420px) { .seg-4 { grid-template-columns: repeat(2, 1fr); } }
.seg input { position: absolute; opacity: 0; pointer-events: none; }
.seg label {
  display: flex; flex-direction: column; justify-content: center; text-align: center;
  border: 1.5px solid var(--line); border-radius: var(--radius-sm);
  padding: 8px 6px; min-height: 52px; cursor: pointer; font-weight: 600; font-size: .9rem; margin: 0; line-height: 1.25;
  background: var(--surface);
}
.seg label small { font-weight: 400; color: var(--ink-2); font-size: .76rem; }
.seg input:checked + label { border-color: var(--accent); background: var(--accent-soft); }
.seg input:focus-visible + label { outline: 3px solid var(--accent); outline-offset: 2px; }

.check { display: flex; gap: 10px; align-items: flex-start; padding: 10px 12px; border: 1.5px solid var(--line); border-radius: var(--radius-sm); cursor: pointer; margin-bottom: 8px; font-size: .95rem; }
.check input { width: 20px; height: 20px; margin: 1px 0 0; accent-color: var(--accent); flex: none; }
.check small { display: block; color: var(--ink-2); font-size: .8rem; }

.helper { background: var(--surface-2); border-radius: var(--radius-sm); padding: 10px 12px; margin-top: 8px; font-size: .9rem; }
.helper summary { cursor: pointer; font-weight: 600; color: var(--accent); }
.helper .grid-2 { margin-top: 10px; }

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  font: inherit; font-weight: 700; font-size: 1rem;
  border-radius: var(--radius-sm); border: 1.5px solid transparent;
  padding: 12px 18px; min-height: 48px; cursor: pointer; text-decoration: none;
}
.btn-primary { background: var(--accent); color: var(--accent-ink); width: 100%; }
.btn-primary:hover { filter: brightness(1.07); }
.btn-ghost { background: transparent; color: var(--ink); border-color: var(--line); }
.btn-ghost:hover { background: var(--surface-2); }
.btn-sm { min-height: 40px; padding: 8px 12px; font-size: .9rem; }
.privacy { display: flex; gap: 8px; align-items: center; color: var(--ink-2); font-size: .85rem; margin: 12px 0 0; }
.privacy svg { width: 16px; height: 16px; flex: none; }
.noscript { background: var(--warn-soft); color: var(--warn); padding: 10px 12px; border-radius: var(--radius-sm); font-weight: 600; }

/* 5. Resultado ------------------------------------------------------------- */
.result-card { position: sticky; top: 12px; }
@media (max-width: 860px) { .result-card { position: static; } }
.result-card[data-state="idle"] .r-done, .result-card[data-state="done"] .r-idle { display: none; }
.r-idle { color: var(--ink-2); text-align: center; padding: 18px 6px; }
.r-idle svg { width: 56px; height: 56px; margin: 0 auto 10px; color: var(--accent); opacity: .8; }
.r-label { font-size: .85rem; text-transform: uppercase; letter-spacing: .06em; color: var(--ink-2); font-weight: 700; margin: 0; }
.r-main { font-size: clamp(2.2rem, 1.6rem + 3vw, 3rem); font-weight: 800; line-height: 1.05; margin: 2px 0 2px; color: var(--ink); font-variant-numeric: tabular-nums; }
.r-main small { font-size: 1rem; font-weight: 600; color: var(--ink-2); }
.r-eq { color: var(--ink-2); margin: 0 0 14px; font-variant-numeric: tabular-nums; }
.r-rec { background: var(--ok-soft); border-radius: var(--radius-sm); padding: 12px 14px; margin-bottom: 12px; }
.r-rec.is-warn { background: var(--warn-soft); }
.r-rec strong { display: block; font-size: 1.15rem; }
.r-rec p { margin: 4px 0 0; font-size: .9rem; color: var(--ink-2); }
.r-break { width: 100%; border-collapse: collapse; font-size: .88rem; margin: 6px 0 12px; font-variant-numeric: tabular-nums; }
.r-break td { padding: 5px 0; border-bottom: 1px solid var(--line); }
.r-break td:last-child { text-align: right; color: var(--ink-2); }
.r-actions { display: flex; gap: 8px; flex-wrap: wrap; }
.r-note { font-size: .82rem; color: var(--ink-2); margin: 12px 0 0; }

/* 6. Contenido ------------------------------------------------------------- */
.content { max-width: 760px; }
.content-grid { display: grid; grid-template-columns: minmax(0, 1fr) 300px; gap: 32px; margin-top: 8px; }
@media (max-width: 980px) { .content-grid { grid-template-columns: minmax(0, 1fr); } }
.toc { position: sticky; top: 12px; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 16px; font-size: .92rem; }
.toc ol { padding-left: 18px; margin: 0; }
.toc li { margin: 4px 0; }
@media (max-width: 980px) { .toc { display: none; } }
.formula { background: var(--surface); border: 1px solid var(--line); border-left: 4px solid var(--accent); border-radius: var(--radius-sm); padding: 12px 14px; font-family: ui-monospace, SFMono-Regular, Consolas, monospace; font-size: .9rem; overflow-x: auto; }
.table-wrap { overflow-x: auto; margin: 0 0 1em; border: 1px solid var(--line); border-radius: var(--radius-sm); background: var(--surface); }
table.data { width: 100%; border-collapse: collapse; font-size: .93rem; font-variant-numeric: tabular-nums; }
table.data th, table.data td { padding: 9px 12px; text-align: left; border-bottom: 1px solid var(--line); white-space: nowrap; }
table.data th { background: var(--surface-2); font-weight: 700; }
table.data tr:last-child td { border-bottom: 0; }
.callout { background: var(--warn-soft); border-radius: var(--radius-sm); padding: 12px 14px; font-size: .93rem; }
.callout strong { color: var(--warn); }
.faq details { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius-sm); margin-bottom: 8px; }
.faq summary { cursor: pointer; padding: 12px 14px; font-weight: 700; list-style-position: outside; }
.faq details > div { padding: 0 14px 4px; }
.sources { font-size: .88rem; color: var(--ink-2); }
.meta-line { font-size: .85rem; color: var(--ink-2); }

/* 7. Anuncios ---------------------------------------------------------------
   Los huecos .ad-slot quedan ocultos hasta asignarles un bloque de anuncios de AdSense
   (añadir la clase .is-live). Mientras, los anuncios automáticos de AdSense se colocan solos. */
.ad-slot:not(.is-live) { display: none; }
.ad-slot {
  min-height: 120px; margin: 24px 0;
  border: 1px dashed var(--line); border-radius: var(--radius-sm);
  display: flex; align-items: center; justify-content: center;
  color: var(--ink-2); font-size: .75rem; letter-spacing: .08em; text-transform: uppercase;
  background: transparent;
}
.ad-slot.ad-leaderboard { min-height: 100px; }
@media (max-width: 480px) { .ad-slot.ad-leaderboard { min-height: 280px; } }

/* 8. Tarjetas y hubs -------------------------------------------------------- */
.hero { padding: 28px 0 8px; }
.hero h1 { max-width: 22ch; }
.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 14px; margin: 14px 0 8px; padding: 0; list-style: none; }
.card {
  display: block; height: 100%; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 16px; color: var(--ink); text-decoration: none; transition: border-color .15s, transform .15s;
}
a.card:hover { border-color: var(--accent); transform: translateY(-1px); }
.card h3 { margin: 6px 0 4px; font-size: 1.05rem; }
.card p { margin: 0; color: var(--ink-2); font-size: .92rem; }
.card .tag { display: inline-block; font-size: .72rem; font-weight: 700; text-transform: uppercase; letter-spacing: .06em; color: var(--accent); }
.card.soon { opacity: .65; }
.card.soon .tag { color: var(--ink-2); }
.cat-icon { width: 34px; height: 34px; color: var(--brand); }

/* 9. Pie --------------------------------------------------------------------- */
.site-footer { margin-top: 48px; border-top: 1px solid var(--line); background: var(--surface); font-size: .9rem; color: var(--ink-2); }
.site-footer .wrap { padding-top: 24px; padding-bottom: 28px; display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 20px; }
@media (max-width: 720px) {
  .site-footer .wrap { grid-template-columns: 1fr 1fr; gap: 16px; }
  .site-footer .wrap > div:first-child { grid-column: 1 / -1; }
}
.site-footer ul { list-style: none; padding: 0; margin: 0; }
.site-footer li { margin: 4px 0; }
.site-footer a { color: var(--ink-2); }
.site-footer h2 { font-size: .9rem; margin: 0 0 8px; color: var(--ink); text-transform: uppercase; letter-spacing: .06em; }

/* 10. Utilidades ------------------------------------------------------------- */
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0; }
.mt-0 { margin-top: 0; }
.toast { position: fixed; left: 50%; bottom: 20px; transform: translateX(-50%); background: var(--ink); color: var(--bg); padding: 10px 16px; border-radius: 999px; font-weight: 600; font-size: .9rem; opacity: 0; pointer-events: none; transition: opacity .2s; z-index: 20; }
.toast.show { opacity: 1; }
@media print {
  .site-header, .site-footer, .ad-slot, .tool-card, .r-actions, .toc, .breadcrumbs { display: none !important; }
  .tool-layout { display: block; }
  .result-card { box-shadow: none; border: 1px solid #999; }
}