/* ═══════════════════════════════════════════════════════════════════
   multicalci.com — CALC SUITE
   Shared stylesheet for individual calculator pages.
   Path: /assets/calc-suite.css

   Used by the per-calculator SEO pages (one calculator = one URL).
   NOT used by the four discipline hub pages — those keep their own
   inline styles and are deliberately untouched.

   Class vernacular is inherited from the civil + electrical hubs so
   that existing render code ports across unchanged.
═══════════════════════════════════════════════════════════════════ */


/* ══════════════════════════════
   1. TOKENS
══════════════════════════════ */
:root {
  /* Structure */
  --ink:      #0f2044;   /* navy — headings, chrome            */
  --ink2:     #1a3260;
  --ink3:     #3d5080;   /* secondary text                     */
  --muted:    #7a8fb5;   /* captions, meta                     */

  /* Surfaces */
  --paper:    #f4f6fb;   /* page background — blueprint paper  */
  --surface:  #ffffff;   /* cards                              */
  --surface2: #eef1f8;   /* wells, hover                       */
  --surface3: #e3e8f4;

  /* Rules */
  --rule:     #d6dced;
  --rule2:    #bfc9e0;

  /* Interactive */
  --cobalt:   #1e4db7;
  --cobalt2:  #2563eb;
  --cobalt-bg:#e8f0fe;
  --cobalt-bd:#c5d5f5;

  /* Signal — computed results, active state. Used sparingly. */
  --signal:   #b45309;
  --signal2:  #92400e;
  --signal-bg:#fffbeb;
  --signal-bd:#fcd34d;

  /* Status */
  --grn:      #047857;  --grn-bg: #ecfdf5;  --grn-bd: #6ee7b7;
  --red:      #b91c1c;  --red-bg: #fef2f2;  --red-bd: #fca5a5;
  --amb:      #a16207;  --amb-bg: #fefce8;  --amb-bd: #fde047;
  --cyn:      #0e7490;  --cyn-bg: #ecfeff;  --cyn-bd: #a5f3fc;
  --pur:      #6d28d9;  --pur-bg: #f5f3ff;  --pur-bd: #c4b5fd;
  --blu:      #1d4ed8;  --blu-bg: #eff6ff;  --blu-bd: #bfdbfe;

  /* Type */
  --display: 'Saira', system-ui, sans-serif;
  --body:    'Plus Jakarta Sans', system-ui, sans-serif;
  --mono:    'IBM Plex Mono', ui-monospace, monospace;

  /* Geometry */
  --r:   10px;
  --r2:  6px;
  --well: 880px;         /* content measure                    */
  --sh:  0 1px 2px rgba(15,32,68,.05), 0 4px 14px rgba(15,32,68,.05);
  --sh2: 0 8px 28px rgba(15,32,68,.11);
}


/* ══════════════════════════════
   2. RESET + BASE
══════════════════════════════ */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0 }

html {
  font-size: 15px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

body {
  font-family: var(--body);
  background: var(--paper);
  color: var(--ink);
  min-height: 100vh;
  line-height: 1.6;
  background-image:
    radial-gradient(ellipse 60% 40% at 10% -10%, rgba(30,77,183,.05) 0%, transparent 60%),
    radial-gradient(ellipse 50% 30% at 95% 105%, rgba(180,83,9,.045) 0%, transparent 60%);
  background-attachment: fixed;
}

a { color: var(--cobalt); text-decoration: none }
a:hover { text-decoration: underline }

:focus-visible {
  outline: 2px solid var(--cobalt2);
  outline-offset: 2px;
  border-radius: 3px;
}

::selection { background: var(--signal-bd); color: var(--ink) }

::-webkit-scrollbar { width: 10px; height: 10px }
::-webkit-scrollbar-track { background: var(--surface2) }
::-webkit-scrollbar-thumb { background: var(--rule2); border-radius: 3px }
::-webkit-scrollbar-thumb:hover { background: var(--ink3) }


/* ══════════════════════════════
   3. PAGE FRAME
══════════════════════════════ */
.wrap {
  max-width: var(--well);
  margin: 0 auto;
  padding: 0 20px 72px;
}

/* Top bar — site identity + back to hub */
.topbar {
  background: var(--ink);
  color: #fff;
  border-bottom: 2px solid var(--signal);
}
.topbar-in {
  max-width: var(--well);
  margin: 0 auto;
  padding: 11px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.brand {
  font-family: var(--display);
  font-weight: 700;
  font-size: 1rem;
  letter-spacing: .04em;
  color: #fff;
}
.brand:hover { text-decoration: none; color: var(--signal-bd) }
.topbar nav { display: flex; gap: 18px; flex-wrap: wrap }
.topbar nav a {
  color: rgba(255,255,255,.72);
  font-size: .8rem;
  font-weight: 600;
}
.topbar nav a:hover { color: #fff; text-decoration: none }


/* ══════════════════════════════
   4. BREADCRUMB
══════════════════════════════ */
.crumb {
  font-size: .78rem;
  color: var(--ink3);
  padding: 16px 0 0;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 7px;
}
.crumb a { color: var(--ink3); font-weight: 600 }
.crumb a:hover { color: var(--cobalt) }
.crumb .sep { color: var(--rule2); user-select: none }
.crumb [aria-current] { color: var(--ink); font-weight: 700 }


/* ══════════════════════════════
   5. HERO — H1 + standard reference
══════════════════════════════ */
.hero { padding: 22px 0 26px; border-bottom: 1px solid var(--rule) }

/* Mono eyebrow carries the governing standard — see .stdref */
.eyebrow {
  font-family: var(--mono);
  font-size: .68rem;
  font-weight: 600;
  letter-spacing: .13em;
  text-transform: uppercase;
  color: var(--signal2);
  display: block;
  margin-bottom: 9px;
}

h1 {
  font-family: var(--display);
  font-size: clamp(1.7rem, 4.4vw, 2.45rem);
  font-weight: 700;
  line-height: 1.14;
  letter-spacing: -.015em;
  color: var(--ink);
}

.lede {
  margin-top: 12px;
  font-size: 1.02rem;
  color: var(--ink3);
  max-width: 62ch;
}

/* Standard-reference chips under the H1 */
.stdref { display: flex; flex-wrap: wrap; gap: 7px; margin-top: 15px }
.stdref span {
  font-family: var(--mono);
  font-size: .7rem;
  font-weight: 500;
  padding: 3.5px 9px;
  border-radius: var(--r2);
  background: var(--surface);
  border: 1px solid var(--rule);
  color: var(--ink3);
}


/* ══════════════════════════════
   6. SECTION HEADINGS
══════════════════════════════ */
h2 {
  font-family: var(--display);
  font-size: 1.3rem;
  font-weight: 700;
  letter-spacing: -.005em;
  color: var(--ink);
  margin: 40px 0 14px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--rule);
  position: relative;
}
h2::after {
  content: '';
  position: absolute;
  left: 0; bottom: -2px;
  width: 46px; height: 2px;
  background: var(--signal);
}
h3 {
  font-family: var(--display);
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--ink2);
  margin: 24px 0 9px;
}
p { margin: 0 0 13px; color: var(--ink3) }
p strong { color: var(--ink); font-weight: 700 }

hr.dv { border: 0; border-top: 1px solid var(--rule); margin: 20px 0 }

ul, ol { margin: 0 0 14px 22px; color: var(--ink3) }
li { margin-bottom: 6px }


/* ══════════════════════════════
   7. CARD
══════════════════════════════ */
.card {
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: var(--r);
  box-shadow: var(--sh);
  margin-bottom: 20px;
  overflow: hidden;
}
.card:last-child { margin-bottom: 0 }

.card-hd {
  background: var(--surface2);
  border-bottom: 1px solid var(--rule);
  padding: 13px 18px;
  display: flex;
  align-items: center;
  gap: 10px;
}
.card-hd-ico { font-size: 1.05rem; line-height: 1; flex-shrink: 0 }
.card-hd-ttl {
  font-family: var(--display);
  font-weight: 700;
  font-size: .95rem;
  letter-spacing: .01em;
  color: var(--ink);
}
.card-bd { padding: 18px }


/* ══════════════════════════════
   8. FORM FIELDS
══════════════════════════════ */
.g2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 13px }
.g3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 13px }

.field { margin-bottom: 13px }
.field:last-child { margin-bottom: 0 }

.field label {
  display: block;
  font-size: .74rem;
  font-weight: 700;
  letter-spacing: .03em;
  text-transform: uppercase;
  color: var(--ink3);
  margin-bottom: 5px;
}
.field label .u { font-family: var(--mono); font-weight: 500; text-transform: none; color: var(--muted) }

.field input,
.field select {
  width: 100%;
  padding: 9px 11px;
  font-family: var(--mono);
  font-size: .88rem;
  font-variant-numeric: tabular-nums slashed-zero;
  color: var(--ink);
  background: var(--surface);
  border: 1.5px solid var(--rule2);
  border-radius: var(--r2);
  transition: border-color .13s, box-shadow .13s;
}
.field select { font-family: var(--body); cursor: pointer }

.field input:hover,
.field select:hover { border-color: var(--ink3) }

.field input:focus,
.field select:focus {
  outline: none;
  border-color: var(--cobalt2);
  box-shadow: 0 0 0 3px rgba(37,99,235,.13);
}
.field input:invalid:not(:placeholder-shown) { border-color: var(--red) }

.hint { font-size: .72rem; color: var(--muted); margin-top: 4px }


/* ══════════════════════════════
   9. BUTTONS
══════════════════════════════ */
.btn-calc {
  width: 100%;
  padding: 11px 18px;
  font-family: var(--display);
  font-size: .92rem;
  font-weight: 700;
  letter-spacing: .03em;
  color: #fff;
  background: var(--ink);
  border: 0;
  border-radius: var(--r2);
  cursor: pointer;
  transition: background .13s, transform .08s, box-shadow .13s;
}
.btn-calc:hover { background: var(--ink2); box-shadow: var(--sh2) }
.btn-calc:active { transform: translateY(1px) }
.btn-calc:disabled { background: var(--rule2); cursor: not-allowed; box-shadow: none }

.btn-pdf {
  padding: 8px 15px;
  font-family: var(--body);
  font-size: .8rem;
  font-weight: 700;
  color: var(--ink);
  background: var(--surface);
  border: 1.5px solid var(--rule2);
  border-radius: var(--r2);
  cursor: pointer;
  transition: background .13s, border-color .13s;
}
.btn-pdf:hover { background: var(--surface2); border-color: var(--ink3) }

.btn-row { display: flex; flex-wrap: wrap; gap: 9px; align-items: center }


/* ══════════════════════════════
   10. UNIT TOGGLE
══════════════════════════════ */
.utog {
  display: inline-flex;
  background: var(--surface2);
  border: 1px solid var(--rule);
  border-radius: var(--r2);
  padding: 2.5px;
  gap: 2.5px;
}
.ubtn {
  padding: 5px 13px;
  font-family: var(--mono);
  font-size: .74rem;
  font-weight: 600;
  color: var(--ink3);
  background: transparent;
  border: 0;
  border-radius: 4px;
  cursor: pointer;
  transition: background .13s, color .13s;
}
.ubtn:hover:not(.on) { background: var(--surface3); color: var(--ink) }
.ubtn.on { background: var(--ink); color: #fff }


/* ══════════════════════════════
   11. RESULTS — the calculation stamp
   Values set in tabular mono so they align down the column.
══════════════════════════════ */
.results { display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px }

.rc {
  background: var(--surface2);
  border: 1px solid var(--rule);
  border-top: 3px solid var(--ink3);
  border-radius: var(--r2);
  padding: 12px 14px;
  transition: box-shadow .13s;
}
.rc:hover { box-shadow: var(--sh) }
.rc.sp2 { grid-column: span 2 }

/* Primary computed result — the one number the engineer came for */
.rc.c-main { border-top-color: var(--signal); background: var(--signal-bg) }
.rc.c-grn  { border-top-color: var(--grn); background: var(--grn-bg) }
.rc.c-red  { border-top-color: var(--red); background: var(--red-bg) }
.rc.c-amb  { border-top-color: var(--amb); background: var(--amb-bg) }
.rc.c-blu  { border-top-color: var(--blu); background: var(--blu-bg) }
.rc.c-cyn  { border-top-color: var(--cyn); background: var(--cyn-bg) }
.rc.c-pur  { border-top-color: var(--pur); background: var(--pur-bg) }

.rl {
  font-size: .71rem;
  font-weight: 700;
  letter-spacing: .045em;
  text-transform: uppercase;
  color: var(--ink3);
  margin-bottom: 5px;
}

.rv {
  font-family: var(--mono);
  font-size: 1.12rem;
  font-weight: 600;
  font-variant-numeric: tabular-nums slashed-zero;
  color: var(--ink);
  line-height: 1.25;
  word-break: break-word;
}
.rv.big { font-size: 1.62rem; font-weight: 700 }
.rv.v-main { color: var(--signal2) }
.rv.v-grn  { color: var(--grn) }
.rv.v-red  { color: var(--red) }
.rv.v-amb  { color: var(--amb) }
.rv.v-blu  { color: var(--blu) }
.rv.v-cyn  { color: var(--cyn) }
.rv.v-pur  { color: var(--pur) }

/* Units sit quietly beside the figure */
.rv .un { font-size: .68em; font-weight: 500; color: var(--muted); margin-left: 3px }

.rsub {
  font-family: var(--mono);
  font-size: .72rem;
  color: var(--muted);
  margin-top: 4px;
  font-variant-numeric: tabular-nums slashed-zero;
}

/* Empty state — an invitation to act, not an apology */
.rc-empty {
  grid-column: 1 / -1;
  text-align: center;
  padding: 26px 18px;
  color: var(--muted);
  font-size: .87rem;
  border: 1.5px dashed var(--rule2);
  border-radius: var(--r2);
  background: var(--surface);
}


/* ══════════════════════════════
   12. BADGES
══════════════════════════════ */
.badge {
  display: inline-block;
  padding: 3px 9px;
  font-size: .71rem;
  font-weight: 700;
  border-radius: 20px;
  border: 1px solid;
  margin: 2px 3px 2px 0;
}
.badge.ok   { background: var(--grn-bg); color: var(--grn); border-color: var(--grn-bd) }
.badge.warn { background: var(--amb-bg); color: var(--amb); border-color: var(--amb-bd) }
.badge.err  { background: var(--red-bg); color: var(--red); border-color: var(--red-bd) }
.badge.info { background: var(--cobalt-bg); color: var(--cobalt); border-color: var(--cobalt-bd) }

/* Inline validation message under a field or result block */
.validation-err {
  display: block;
  color: var(--red);
  font-size: .8rem;
  font-weight: 600;
  margin-top: 6px;
}


/* ══════════════════════════════
   13. FORMULA SLAB
   Dark navy — carried over from the civil/electrical hubs.
══════════════════════════════ */
.fbox {
  position: relative;
  background: var(--ink);
  border-radius: var(--r2);
  padding: 15px 17px;
  margin: 15px 0;
  font-family: var(--mono);
  font-size: .82rem;
  line-height: 1.95;
  color: rgba(255,255,255,.7);
  overflow-x: auto;
}
.fbox::before {
  content: 'FORMULA';
  position: absolute;
  top: 9px; right: 13px;
  font-size: .6rem;
  font-weight: 600;
  letter-spacing: .16em;
  color: rgba(255,255,255,.24);
}
.fbox .ht { color: #93c5fd }              /* term / variable      */
.fbox .hi { color: var(--signal-bd); font-weight: 600 }  /* result */
.fbox .cm { color: rgba(255,255,255,.36); font-style: italic }  /* note */

/* Variable legend under a formula */
.legend { font-size: .8rem; color: var(--ink3); margin-top: 10px }
.legend code {
  font-family: var(--mono);
  font-size: .84em;
  background: var(--surface2);
  border: 1px solid var(--rule);
  border-radius: 3px;
  padding: 1px 5px;
  color: var(--ink);
}


/* ══════════════════════════════
   14. TABLES
══════════════════════════════ */
.tbl-wrap { overflow-x: auto; margin: 14px 0; -webkit-overflow-scrolling: touch }

.tbl {
  width: 100%;
  border-collapse: collapse;
  font-size: .84rem;
  min-width: 420px;
}
.tbl th {
  background: var(--ink);
  color: rgba(255,255,255,.85);
  font-size: .71rem;
  font-weight: 700;
  letter-spacing: .05em;
  text-transform: uppercase;
  text-align: left;
  padding: 9px 12px;
  white-space: nowrap;
}
.tbl th:first-child { border-top-left-radius: var(--r2) }
.tbl th:last-child  { border-top-right-radius: var(--r2) }

.tbl td {
  padding: 9px 12px;
  border-bottom: 1px solid var(--rule);
  font-family: var(--mono);
  font-size: .82rem;
  font-variant-numeric: tabular-nums slashed-zero;
  color: var(--ink3);
}
.tbl td:first-child {
  font-family: var(--body);
  font-weight: 600;
  color: var(--ink);
}
.tbl tr:nth-child(even) td { background: var(--surface2) }
.tbl tr:hover td { background: var(--cobalt-bg) }
.tbl tr.hl td { background: var(--signal-bg); color: var(--signal2); font-weight: 700 }


/* ══════════════════════════════
   15. WORKED EXAMPLE
══════════════════════════════ */
.wex {
  background: var(--surface);
  border: 1px solid var(--rule);
  border-left: 3px solid var(--cobalt);
  border-radius: var(--r2);
  padding: 16px 18px;
  margin: 15px 0;
}
.wex-hd {
  font-family: var(--display);
  font-size: .8rem;
  font-weight: 700;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--cobalt);
  margin-bottom: 11px;
}
.wex dl { display: grid; grid-template-columns: auto 1fr; gap: 5px 16px; font-size: .86rem }
.wex dt { color: var(--ink3); font-weight: 600 }
.wex dd {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums slashed-zero;
  color: var(--ink);
}
.wex .ans {
  margin-top: 13px;
  padding-top: 11px;
  border-top: 1px solid var(--rule);
  font-family: var(--mono);
  font-size: 1rem;
  font-weight: 700;
  font-variant-numeric: tabular-nums slashed-zero;
  color: var(--signal2);
}


/* ══════════════════════════════
   16. FAQ
══════════════════════════════ */
.faq details {
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: var(--r2);
  margin-bottom: 9px;
  overflow: hidden;
}
.faq summary {
  padding: 13px 16px;
  font-weight: 700;
  font-size: .92rem;
  color: var(--ink);
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  transition: background .13s;
}
.faq summary::-webkit-details-marker { display: none }
.faq summary::after {
  content: '+';
  font-family: var(--mono);
  font-size: 1.15rem;
  font-weight: 400;
  color: var(--muted);
  flex-shrink: 0;
  transition: transform .18s;
}
.faq details[open] summary::after { transform: rotate(45deg) }
.faq summary:hover { background: var(--surface2) }
.faq details[open] summary { border-bottom: 1px solid var(--rule) }
.faq-a { padding: 13px 16px; font-size: .89rem; color: var(--ink3) }
.faq-a p:last-child { margin-bottom: 0 }


/* ══════════════════════════════
   17. RELATED LINKS + HUB LINK
══════════════════════════════ */
.related { display: grid; grid-template-columns: repeat(auto-fill, minmax(215px, 1fr)); gap: 10px }
.related a {
  display: block;
  padding: 12px 14px;
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: var(--r2);
  font-size: .87rem;
  font-weight: 600;
  color: var(--ink);
  transition: border-color .13s, box-shadow .13s, transform .13s;
}
.related a:hover {
  border-color: var(--cobalt);
  box-shadow: var(--sh);
  transform: translateY(-1px);
  text-decoration: none;
}
.related a .d { display: block; font-size: .76rem; font-weight: 400; color: var(--muted); margin-top: 3px }

.hublink {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  margin-top: 26px;
  padding: 10px 16px;
  background: var(--surface);
  border: 1.5px solid var(--rule2);
  border-radius: var(--r2);
  font-size: .87rem;
  font-weight: 700;
  color: var(--ink);
}
.hublink:hover { border-color: var(--cobalt); color: var(--cobalt); text-decoration: none }


/* ══════════════════════════════
   18. NOTES + FOOTER
══════════════════════════════ */
.note {
  background: var(--signal-bg);
  border: 1px solid var(--signal-bd);
  border-radius: var(--r2);
  padding: 12px 15px;
  font-size: .85rem;
  color: var(--signal2);
  margin: 15px 0;
}
.note strong { color: var(--signal2) }

.foot {
  border-top: 1px solid var(--rule);
  margin-top: 44px;
  padding-top: 20px;
  font-size: .8rem;
  color: var(--muted);
}
.foot a { color: var(--ink3); font-weight: 600 }


/* ══════════════════════════════
   19. UTILITIES
══════════════════════════════ */
.mono { font-family: var(--mono); font-variant-numeric: tabular-nums slashed-zero }
.tc { text-align: center }
.tr { text-align: right }
.mt0 { margin-top: 0 }
.mb0 { margin-bottom: 0 }
.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;
}


/* ══════════════════════════════
   20. RESPONSIVE
══════════════════════════════ */
@media (max-width: 720px) {
  html { font-size: 14.5px }
  .wrap { padding: 0 15px 52px }
  .topbar-in { padding: 10px 15px; flex-wrap: wrap; gap: 9px }
  .g2, .g3, .results { grid-template-columns: 1fr }
  .rc.sp2 { grid-column: span 1 }
  .card-bd { padding: 15px }
  .wex dl { grid-template-columns: 1fr; gap: 2px }
  .wex dd { margin-bottom: 8px }
  h2 { margin-top: 32px }
}

@media (max-width: 420px) {
  .topbar nav { gap: 13px }
  .rv.big { font-size: 1.4rem }
}


/* ══════════════════════════════
   21. MOTION PREFERENCE
══════════════════════════════ */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto }
  *, *::before, *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }
}


/* ══════════════════════════════
   22. PRINT
══════════════════════════════ */
@media print {
  * { -webkit-print-color-adjust: exact !important; print-color-adjust: exact !important }
  body { background: #fff; background-image: none; font-size: 11pt }
  .topbar, .crumb, .faq, .related, .hublink, .btn-calc, .btn-pdf, .btn-row, .utog { display: none !important }
  .wrap { max-width: 100%; padding: 0 }
  .card { box-shadow: none; border: 1px solid #ccc; break-inside: avoid }
  .rc, .wex, .fbox { break-inside: avoid }
  h2 { break-after: avoid }
  a { color: inherit; text-decoration: none }
}