/* Construction Calculators — construction.praveshsinghal.com
   Shared design system: minimal, fast, matches the Pravesh Singhal tool network */

:root {
  --color-accent: #5b47e0;
  --color-accent-dark: #4634b8;
  --color-accent-light: #f1eefc;
  --color-bg: #ffffff;
  --color-bg-alt: #f7f7fb;
  --color-text: #1b1c22;
  --color-text-muted: #5c5f6c;
  --color-border: #e7e7ee;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --shadow-sm: 0 1px 2px rgba(20,20,30,.06);
  --shadow-md: 0 6px 20px rgba(20,20,30,.08);
  --max-width: 1120px;
  --font: -apple-system, BlinkMacSystemFont, "Inter", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0; font-family: var(--font); color: var(--color-text); background: var(--color-bg);
  line-height: 1.55; font-size: 16px; -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; display: block; }
a { color: var(--color-accent); text-decoration: none; }
a:hover { text-decoration: underline; }
h1, h2, h3, h4 { line-height: 1.2; margin: 0 0 .5em; font-weight: 800; letter-spacing: -.01em; }
p { margin: 0 0 1em; }
.container { max-width: var(--max-width); margin: 0 auto; padding: 0 20px; }

/* ---------- Header ---------- */
.site-header { border-bottom: 1px solid var(--color-border); position: sticky; top: 0; background: rgba(255,255,255,.92); backdrop-filter: blur(8px); z-index: 50; }
.site-header .container { display: flex; align-items: center; justify-content: space-between; height: 66px; gap: 16px; }
.site-logo { display: flex; align-items: center; gap: 10px; font-weight: 800; font-size: 1.08rem; color: var(--color-text); }
.site-logo:hover { text-decoration: none; }
.site-logo .logo-badge { width: 34px; height: 34px; border-radius: 9px; background: var(--color-accent); color: #fff; display: flex; align-items: center; justify-content: center; font-size: 1.1rem; flex: none; }
.site-logo .brand-sub { font-weight: 500; font-size: .72rem; color: var(--color-text-muted); display: block; }
.main-nav { display: flex; align-items: center; gap: 22px; }
.main-nav a { color: var(--color-text); font-weight: 600; font-size: .92rem; }
.main-nav a.is-active { color: var(--color-accent); }
.menu-toggle { display: none; background: none; border: 1px solid var(--color-border); border-radius: 8px; width: 40px; height: 40px; cursor: pointer; }
.menu-toggle span { display: block; width: 18px; height: 2px; background: var(--color-text); margin: 4px auto; }

/* ---------- Buttons ---------- */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; padding: 12px 20px; border-radius: var(--radius-md); font-weight: 700; font-size: .92rem; cursor: pointer; border: none; }
.btn-primary { background: var(--color-accent); color: #fff; }
.btn-primary:hover { background: var(--color-accent-dark); text-decoration: none; }
.btn-secondary { background: var(--color-bg-alt); color: var(--color-text); border: 1px solid var(--color-border); }
.btn-secondary:hover { background: #eef0f5; text-decoration: none; }
.btn-sm { padding: 8px 14px; font-size: .82rem; }

/* ---------- Hero ---------- */
.hero { padding: 56px 0 40px; text-align: center; background: linear-gradient(180deg, var(--color-accent-light), #fff 70%); }
.hero h1 { font-size: 2.3rem; max-width: 780px; margin: 0 auto .5em; }
.hero p.lead { max-width: 620px; margin: 0 auto 1.6em; color: var(--color-text-muted); font-size: 1.05rem; }
.hero-stats { display: flex; justify-content: center; gap: 30px; flex-wrap: wrap; margin-top: 26px; font-size: .85rem; color: var(--color-text-muted); }
.hero-stats strong { color: var(--color-text); display: block; font-size: 1.3rem; }

.search-box { max-width: 480px; margin: 0 auto; position: relative; }
.search-box input { width: 100%; padding: 14px 16px; border-radius: 999px; border: 1px solid var(--color-border); font-size: .95rem; box-shadow: var(--shadow-sm); }

/* ---------- Sections ---------- */
.section { padding: 48px 0; }
.section-alt { background: var(--color-bg-alt); }
.section-head { text-align: center; max-width: 640px; margin: 0 auto 32px; }
.section-head h2 { font-size: 1.7rem; }
.section-head p { color: var(--color-text-muted); }

/* ---------- Calculator grid / cards ---------- */
.calc-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 16px; }
.calc-card { border: 1px solid var(--color-border); border-radius: var(--radius-md); padding: 20px; background: #fff; transition: transform .12s, box-shadow .12s; }
.calc-card:hover { transform: translateY(-2px); box-shadow: var(--shadow-md); text-decoration: none; }
.calc-card .emoji { font-size: 1.6rem; width: 46px; height: 46px; display: flex; align-items: center; justify-content: center; background: var(--color-accent-light); border-radius: 10px; margin-bottom: 12px; }
.calc-card h3 { font-size: 1.02rem; margin-bottom: 6px; color: var(--color-text); }
.calc-card p { font-size: .84rem; color: var(--color-text-muted); margin: 0; }

/* ---------- Feature grid ---------- */
.feature-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 22px; }
.feature-item .emoji { font-size: 1.5rem; margin-bottom: 8px; }
.feature-item h3 { font-size: 1rem; margin-bottom: 4px; }
.feature-item p { font-size: .86rem; color: var(--color-text-muted); }

/* ---------- Breadcrumb ---------- */
.breadcrumb { font-size: .78rem; color: var(--color-text-muted); padding: 14px 0 0; }
.breadcrumb a { color: var(--color-text-muted); }

/* ---------- Calculator tool page layout ---------- */
.calc-page-head { padding: 26px 0 6px; }
.calc-page-head h1 { font-size: 1.7rem; margin-bottom: 6px; }
.calc-page-head p { color: var(--color-text-muted); max-width: 700px; }

.calc-tool { display: grid; grid-template-columns: 1.1fr .9fr; gap: 24px; padding: 20px 0 40px; align-items: start; }
@media (max-width: 860px) { .calc-tool { grid-template-columns: 1fr; } }

.calc-panel, .result-panel { background: #fff; border: 1px solid var(--color-border); border-radius: var(--radius-lg); padding: 22px; box-shadow: var(--shadow-sm); }
.calc-panel h2, .result-panel h2 { font-size: 1.02rem; margin-bottom: 14px; }

.field { margin-bottom: 14px; }
.field label { display: block; font-size: .8rem; font-weight: 700; margin-bottom: 5px; color: var(--color-text); }
.field .hint { font-size: .72rem; color: var(--color-text-muted); margin-top: 3px; }
.field input, .field select {
  width: 100%; padding: 10px 12px; border: 1px solid var(--color-border); border-radius: var(--radius-sm);
  font-size: .92rem; font-family: var(--font); background: #fff; color: var(--color-text);
}
.field input:focus, .field select:focus { outline: 2px solid var(--color-accent); outline-offset: 1px; }
.field-row { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
@media (max-width: 480px) { .field-row { grid-template-columns: 1fr; } }

.repeater-table { width: 100%; border-collapse: collapse; margin-bottom: 10px; }
.repeater-table th { text-align: left; font-size: .7rem; text-transform: uppercase; color: var(--color-text-muted); padding-bottom: 6px; }
.repeater-table td { padding: 4px 4px 4px 0; vertical-align: top; }
.repeater-table input { padding: 8px 10px; font-size: .85rem; }
.remove-row-btn { background: none; border: none; color: #b91c1c; font-size: 1.1rem; cursor: pointer; padding: 4px 8px; }
.add-row-btn { background: var(--color-accent-light); color: var(--color-accent-dark); border: none; border-radius: var(--radius-sm); padding: 8px 14px; font-size: .8rem; font-weight: 700; cursor: pointer; }

.result-panel { position: sticky; top: 86px; }
.result-list { list-style: none; margin: 0 0 16px; padding: 0; }
.result-list li { display: flex; justify-content: space-between; gap: 10px; padding: 10px 0; border-bottom: 1px dashed var(--color-border); font-size: .9rem; }
.result-list li:last-child { border-bottom: none; }
.result-list li.primary { background: var(--color-accent-light); border-radius: var(--radius-sm); padding: 12px 14px; margin-bottom: 4px; border-bottom: none; }
.result-list li.primary .r-label { font-weight: 700; color: var(--color-accent-dark); }
.result-list li.primary .r-value { font-weight: 800; color: var(--color-accent-dark); font-size: 1.05rem; }
.result-list .r-label { color: var(--color-text-muted); }
.result-list .r-value { font-weight: 700; }

.result-actions { display: flex; gap: 8px; flex-wrap: wrap; }
.result-actions .btn { flex: 1 1 auto; }
.result-note { font-size: .75rem; color: var(--color-text-muted); margin-top: 12px; padding-top: 12px; border-top: 1px solid var(--color-border); }

/* ---------- Related calculators ---------- */
.related-links { display: flex; flex-wrap: wrap; gap: 8px; }
.related-links a { background: var(--color-bg-alt); border: 1px solid var(--color-border); padding: 8px 14px; border-radius: 999px; font-size: .82rem; font-weight: 600; color: var(--color-text); }
.related-links a:hover { border-color: var(--color-accent); text-decoration: none; }

/* ---------- FAQ ---------- */
.faq-item { border: 1px solid var(--color-border); border-radius: var(--radius-sm); padding: 14px 16px; margin-bottom: 10px; background: #fff; }
.faq-item summary { font-weight: 700; cursor: pointer; font-size: .92rem; }
.faq-item p { margin: 10px 0 0; color: var(--color-text-muted); font-size: .88rem; }

/* ---------- How-it-works steps ---------- */
.steps-list { counter-reset: step; list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(auto-fit, minmax(200px,1fr)); gap: 18px; }
.steps-list li { position: relative; padding-left: 44px; font-size: .88rem; color: var(--color-text-muted); }
.steps-list li::before { counter-increment: step; content: counter(step); position: absolute; left: 0; top: 0; width: 30px; height: 30px; border-radius: 50%; background: var(--color-accent); color: #fff; font-weight: 800; display: flex; align-items: center; justify-content: center; font-size: .85rem; }
.steps-list li strong { display: block; color: var(--color-text); margin-bottom: 3px; }

/* ---------- Ad slots ---------- */
.ad-slot { max-width: var(--max-width); margin: 24px auto; padding: 0 20px; text-align: center; }
.ad-slot .ad-placeholder { border: 1px dashed var(--color-border); border-radius: var(--radius-sm); padding: 14px; font-size: .72rem; color: var(--color-text-muted); background: var(--color-bg-alt); }

/* ---------- Contact form ---------- */
.contact-form { max-width: 560px; }
.contact-form input, .contact-form textarea { width: 100%; padding: 12px 14px; border: 1px solid var(--color-border); border-radius: var(--radius-sm); font-size: .92rem; font-family: var(--font); margin-bottom: 14px; }
.contact-form textarea { min-height: 130px; resize: vertical; }

/* ---------- Content pages ---------- */
.content-page { padding: 30px 0 50px; }
.content-page .container { max-width: 800px; }
.content-page h2 { font-size: 1.25rem; margin-top: 1.6em; }
.content-page ul { padding-left: 20px; }
.page-hero { padding: 40px 0 10px; text-align: center; }
.page-hero h1 { font-size: 2rem; }
.page-hero p { color: var(--color-text-muted); max-width: 600px; margin: 0 auto; }

/* ---------- Footer ---------- */
.site-footer { background: #16171d; color: #c7c8d1; padding: 44px 0 24px; margin-top: 30px; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 30px; margin-bottom: 30px; }
@media (max-width: 720px) { .footer-grid { grid-template-columns: 1fr 1fr; } }
.footer-col h4 { color: #fff; font-size: .82rem; text-transform: uppercase; letter-spacing: .04em; margin-bottom: 12px; }
.footer-col a { display: block; color: #c7c8d1; font-size: .86rem; margin-bottom: 8px; }
.footer-col a:hover { color: #fff; }
.footer-brand .site-logo { color: #fff; }
.footer-brand p { font-size: .84rem; color: #9a9cab; margin-top: 10px; max-width: 320px; }
.footer-bottom { border-top: 1px solid #2a2b34; padding-top: 18px; display: flex; justify-content: space-between; flex-wrap: wrap; gap: 10px; font-size: .78rem; color: #8b8d99; }
.footer-tools { display: flex; gap: 12px; flex-wrap: wrap; }
.footer-tools a { color: #8b8d99; }

/* ---------- Utility ---------- */
.text-center { text-align: center; }
.mt-0 { margin-top: 0; }
.visually-hidden { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0,0,0,0); }

@media (max-width: 720px) {
  .main-nav { position: fixed; inset: 66px 0 0 0; background: #fff; flex-direction: column; align-items: flex-start; padding: 20px; gap: 4px; transform: translateX(100%); transition: transform .2s; overflow-y: auto; }
  .main-nav.is-open { transform: translateX(0); }
  .main-nav a { display: block; width: 100%; padding: 12px 0; border-bottom: 1px solid var(--color-border); }
  .menu-toggle { display: block; }
  .hero h1 { font-size: 1.7rem; }
}

@media print {
  .site-header, .site-footer, .ad-slot, .result-actions, .calc-panel, .related-links, .breadcrumb, .section:not(.print-area) { display: none !important; }
}