/* ObraCalc – Construction Orange Theme */
:root {
  --primary: #f97316;
  --primary-dark: #ea580c;
  --primary-light: #fed7aa;
  --secondary: #1e293b;
  --bg: #f8fafc;
  --card-bg: #ffffff;
  --text: #1e293b;
  --text-muted: #64748b;
  --border: #e2e8f0;
  --success: #16a34a;
  --error: #dc2626;
  --radius: 10px;
  --shadow: 0 1px 3px rgba(0,0,0,.08), 0 4px 12px rgba(0,0,0,.06);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  font-size: 16px;
}

/* ── Header ── */
header {
  background: var(--secondary);
  color: #fff;
  padding: 0 1rem;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 8px rgba(0,0,0,.2);
}

.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
  gap: 1rem;
}

.logo {
  font-size: 1.4rem;
  font-weight: 800;
  color: #fff;
  text-decoration: none;
  letter-spacing: -0.5px;
}

.logo span { color: var(--primary); }

nav { display: flex; gap: .5rem; align-items: center; flex-wrap: wrap; }
nav a {
  color: #cbd5e1;
  text-decoration: none;
  font-size: .9rem;
  padding: .3rem .6rem;
  border-radius: 6px;
  transition: color .2s, background .2s;
}
nav a:hover { color: #fff; background: rgba(255,255,255,.1); }

.lang-switcher {
  display: flex;
  gap: .25rem;
  flex-wrap: wrap;
}
.lang-switcher a {
  font-size: .78rem;
  padding: .2rem .45rem;
  border: 1px solid #475569;
  border-radius: 4px;
  color: #94a3b8;
  text-decoration: none;
  transition: all .2s;
}
.lang-switcher a:hover, .lang-switcher a.active {
  background: var(--primary);
  border-color: var(--primary);
  color: #fff;
}

/* ── Hero / Banner ── */
.hero {
  background: linear-gradient(135deg, var(--secondary) 0%, #0f172a 100%);
  color: #fff;
  padding: 3rem 1rem;
  text-align: center;
}
.hero h1 { font-size: clamp(1.6rem, 4vw, 2.6rem); font-weight: 800; margin-bottom: .75rem; }
.hero h1 span { color: var(--primary); }
.hero p { color: #94a3b8; font-size: 1.05rem; max-width: 600px; margin: 0 auto; }

/* ── Layout ── */
.container { max-width: 1200px; margin: 0 auto; padding: 1.5rem 1rem; }

/* ── Block grid (homepage) ── */
.blocks-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.25rem;
  margin-top: 1.5rem;
}

.block-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
  box-shadow: var(--shadow);
  transition: transform .2s, box-shadow .2s;
}
.block-card:hover { transform: translateY(-2px); box-shadow: 0 8px 24px rgba(0,0,0,.1); }

.block-card-header {
  display: flex;
  align-items: center;
  gap: .75rem;
  margin-bottom: 1rem;
}
.block-icon {
  width: 42px;
  height: 42px;
  background: var(--primary-light);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.4rem;
  flex-shrink: 0;
}
.block-title { font-size: 1.05rem; font-weight: 700; color: var(--secondary); }

.calc-list { list-style: none; }
.calc-list li { border-top: 1px solid var(--border); }
.calc-list li:first-child { border-top: none; }
.calc-list a {
  display: block;
  padding: .5rem .25rem;
  color: var(--text);
  text-decoration: none;
  font-size: .9rem;
  transition: color .2s, padding-left .2s;
}
.calc-list a:hover { color: var(--primary); padding-left: .5rem; }

/* ── Calculator page ── */
.calc-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
  margin-top: 1.5rem;
}
@media (min-width: 768px) {
  .calc-layout { grid-template-columns: 1fr 1fr; }
}
@media (min-width: 1024px) {
  .calc-layout { grid-template-columns: 5fr 4fr; }
}

.card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  box-shadow: var(--shadow);
}

.card-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--secondary);
  margin-bottom: 1.25rem;
  display: flex;
  align-items: center;
  gap: .5rem;
}
.card-title::before {
  content: '';
  display: inline-block;
  width: 4px;
  height: 1.2em;
  background: var(--primary);
  border-radius: 2px;
}

/* ── Form ── */
.form-group { margin-bottom: 1.25rem; }
.form-group label {
  display: block;
  font-size: .875rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: .4rem;
}
.form-group input {
  width: 100%;
  padding: .8rem 1rem;
  border: 1.5px solid var(--border);
  border-radius: 7px;
  font-size: 1rem;
  color: var(--text);
  background: #fff;
  transition: border-color .2s, box-shadow .2s;
  appearance: none;
}
.form-group input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(249,115,22,.15);
}
.form-group input[type=number] { -moz-appearance: textfield; }
.form-group input[type=number]::-webkit-outer-spin-button,
.form-group input[type=number]::-webkit-inner-spin-button { -webkit-appearance: none; }

.btn-row { display: flex; gap: .75rem; margin-top: 1.5rem; }

.btn {
  padding: .7rem 1.4rem;
  border: none;
  border-radius: 7px;
  font-size: .95rem;
  font-weight: 600;
  cursor: pointer;
  transition: background .2s, transform .15s;
  display: inline-flex;
  align-items: center;
  gap: .4rem;
}
.btn:active { transform: scale(.97); }

.btn-primary {
  background: var(--primary);
  color: #fff;
  flex: 1;
}
.btn-primary:hover { background: var(--primary-dark); }

.btn-secondary {
  background: var(--bg);
  color: var(--text-muted);
  border: 1.5px solid var(--border);
}
.btn-secondary:hover { background: var(--border); }

/* ── Results ── */
.results-panel { min-height: 140px; }
.result-placeholder {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 120px;
  color: var(--text-muted);
  font-size: .9rem;
  border: 2px dashed var(--border);
  border-radius: 8px;
}

.result-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: .75rem 0;
  border-bottom: 1px solid var(--border);
  gap: 1rem;
}
.result-item:last-child { border-bottom: none; }
.result-label { font-size: .85rem; color: var(--text-muted); }
.result-value { font-size: 1.15rem; font-weight: 700; color: var(--primary-dark); white-space: nowrap; }

.result-error {
  background: #fef2f2;
  border: 1px solid #fecaca;
  border-radius: 8px;
  padding: 1rem;
  color: var(--error);
  font-size: .9rem;
}

.copy-btn {
  margin-top: 1rem;
  width: 100%;
  justify-content: center;
}

/* ── Page meta (calculator page top) ── */
.calc-header { margin-bottom: .5rem; }
.calc-header h1 { font-size: clamp(1.3rem, 3vw, 1.9rem); font-weight: 800; color: var(--secondary); }
.calc-header p { color: var(--text-muted); margin-top: .4rem; font-size: .97rem; }
.breadcrumb {
  font-size: .82rem;
  color: var(--text-muted);
  margin-bottom: .75rem;
  display: flex;
  align-items: center;
  gap: .3rem;
  flex-wrap: wrap;
}
.breadcrumb a { color: var(--primary); text-decoration: none; }
.breadcrumb a:hover { text-decoration: underline; }
.breadcrumb-sep { color: var(--border); }

/* ── Related calculators ── */
.related-section { margin-top: 2.5rem; }
.related-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--secondary);
  margin-bottom: 1rem;
}
.related-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: .75rem;
}
.related-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: .9rem 1rem;
  text-decoration: none;
  color: var(--text);
  font-size: .88rem;
  font-weight: 500;
  transition: border-color .2s, color .2s, transform .2s;
  display: block;
}
.related-card:hover {
  border-color: var(--primary);
  color: var(--primary);
  transform: translateY(-1px);
}

/* ── Block page ── */
.block-hero {
  background: linear-gradient(135deg, var(--secondary) 0%, #0f172a 100%);
  color: #fff;
  padding: 2rem 1rem;
}
.block-hero h1 { font-size: clamp(1.4rem, 3.5vw, 2.2rem); font-weight: 800; }
.block-hero h1 span { color: var(--primary); }
.block-hero p { color: #94a3b8; margin-top: .5rem; }

.calcs-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1rem;
  margin-top: 1.5rem;
}
.calc-thumb {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.1rem;
  text-decoration: none;
  color: var(--text);
  display: block;
  transition: transform .2s, box-shadow .2s, border-color .2s;
  box-shadow: var(--shadow);
}
.calc-thumb:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0,0,0,.1);
  border-color: var(--primary);
}
.calc-thumb h3 { font-size: .95rem; font-weight: 700; color: var(--secondary); margin-bottom: .3rem; }
.calc-thumb p { font-size: .82rem; color: var(--text-muted); line-height: 1.4; }
.calc-thumb-num {
  font-size: .72rem;
  font-weight: 700;
  color: var(--primary);
  letter-spacing: .05em;
  margin-bottom: .35rem;
}

/* ── Footer ── */
footer {
  background: var(--secondary);
  color: #94a3b8;
  padding: 2rem 1rem;
  margin-top: 4rem;
  text-align: center;
  font-size: .85rem;
}
footer a { color: var(--primary); text-decoration: none; }
footer a:hover { text-decoration: underline; }
.footer-inner { max-width: 1200px; margin: 0 auto; }
.footer-links { display: flex; justify-content: center; gap: 1.5rem; margin-top: .75rem; flex-wrap: wrap; }

/* ── AdSense placeholders ── */
.ad-slot {
  background: #f1f5f9;
  border: 1px dashed #cbd5e1;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #94a3b8;
  font-size: .75rem;
  letter-spacing: .05em;
  overflow: hidden;
}
.ad-slot-banner { height: 90px; margin: 1rem 0; }
.ad-slot-square { height: 250px; }
.ad-slot-responsive { min-height: 90px; margin: 1.5rem 0; }

/* ── Responsive adjustments ── */
@media (max-width: 640px) {
  .header-inner { flex-wrap: wrap; height: auto; padding: .5rem 0; }
  .lang-switcher { justify-content: center; }
  .btn-row { flex-direction: column; }
  .btn-primary { order: -1; }
}

/* ── Utilities ── */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  border: 0;
}
.mt-1 { margin-top: .5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.text-center { text-align: center; }
.section-title {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--secondary);
  margin-bottom: .25rem;
}
.section-sub {
  color: var(--text-muted);
  font-size: .9rem;
  margin-bottom: 1.5rem;
}

/* ── Intro text ── */
.calc-intro {
  background: var(--card-bg);
  border-left: 4px solid var(--primary);
  border-radius: 0 var(--radius) var(--radius) 0;
  padding: 1rem 1.25rem;
  margin-bottom: 1.25rem;
  font-size: .95rem;
  color: var(--text-muted);
  line-height: 1.7;
}
.calc-intro strong { color: var(--text); }

/* ── Input group headings ── */
.input-group-heading {
  font-size: .72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .07em;
  color: var(--primary-dark);
  margin: 1.25rem 0 .5rem;
  padding-bottom: .3rem;
  border-bottom: 1.5px solid var(--primary-light);
  display: flex;
  align-items: center;
  gap: .35rem;
}
.input-group-heading:first-of-type { margin-top: .1rem; }

/* ── Wastage row ── */
.wastage-group {
  background: #fff7ed;
  border: 1.5px solid #fed7aa;
  border-radius: 8px;
  padding: .9rem 1rem;
  margin-top: 1rem;
  margin-bottom: .25rem;
}
.wastage-group label { color: var(--primary-dark); }

/* ── Result rows: net vs total ── */
.result-item--net .result-value { color: var(--text-muted); font-size: 1rem; font-weight: 600; }
.result-item--total .result-value { color: var(--primary-dark); font-size: 1.2rem; font-weight: 800; }
.result-item--total { background: #fff7ed; border-radius: 6px; padding: .6rem .4rem; }
.result-section-title {
  font-size: .7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .08em;
  color: var(--text-muted);
  padding: .5rem 0 .25rem;
  border-bottom: 1px solid var(--border);
  margin-bottom: .25rem;
}

/* ── How to Use section ── */
.howto-section {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  margin-top: 1.5rem;
  box-shadow: var(--shadow);
}
.howto-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--secondary);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: .5rem;
}
.howto-steps { list-style: none; counter-reset: step; }
.howto-steps li {
  counter-increment: step;
  display: flex;
  gap: .85rem;
  align-items: flex-start;
  padding: .6rem 0;
  border-bottom: 1px solid var(--border);
  font-size: .92rem;
  color: var(--text-muted);
  line-height: 1.55;
}
.howto-steps li:last-child { border-bottom: none; }
.howto-steps li::before {
  content: counter(step);
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 26px;
  height: 26px;
  background: var(--primary);
  color: #fff;
  font-size: .75rem;
  font-weight: 800;
  border-radius: 50%;
  flex-shrink: 0;
  margin-top: .05rem;
}

/* ── FAQ section ── */
.faq-section {
  margin-top: 2rem;
}
.faq-title {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--secondary);
  margin-bottom: 1rem;
}
.faq-item {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin-bottom: .75rem;
  box-shadow: var(--shadow);
  overflow: hidden;
}
.faq-q {
  width: 100%;
  background: none;
  border: none;
  padding: 1rem 1.25rem;
  text-align: left;
  font-size: .95rem;
  font-weight: 600;
  color: var(--secondary);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  transition: background .15s;
}
.faq-q:hover { background: var(--bg); }
.faq-q .faq-icon {
  font-size: 1.2rem;
  color: var(--primary);
  flex-shrink: 0;
  transition: transform .25s;
}
.faq-item.open .faq-icon { transform: rotate(45deg); }
.faq-a {
  display: none;
  padding: 0 1.25rem 1rem;
  font-size: .9rem;
  color: var(--text-muted);
  line-height: 1.65;
  border-top: 1px solid var(--border);
}
.faq-item.open .faq-a { display: block; }

/* ── Smooth copy feedback ── */
.btn.copied {
  background: var(--success);
}