/* ── CALCIVUS GLOBAL STYLES ─────────────────────────────────────────── */
:root {
  --bg: #0D1117; --bg2: #161B22; --bg3: #1C2128;
  --border: #30363D; --border2: #21262D;
  --accent: #2563EB; --accent-light: #3B82F6;
  --accent-glow: rgba(37,99,235,0.15);
  --text: #E6EDF3; --text2: #8B949E; --text3: #6E7681;
  --green: #3FB950; --orange: #F0883E; --pink: #FF7B72;
  --cyan: #39C5CF; --yellow: #E3B341;
  --radius: 10px; --radius-lg: 16px;
}
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body { font-family: 'Outfit', system-ui, sans-serif; background: var(--bg); color: var(--text); line-height: 1.6; -webkit-font-smoothing: antialiased; }

/* NAV */
nav { position: sticky; top: 0; z-index: 100; background: rgba(13,17,23,.92); backdrop-filter: blur(12px); border-bottom: 1px solid var(--border2); padding: 0 24px; height: 60px; display: flex; align-items: center; justify-content: space-between; }
.nav-logo { font-size: 22px; font-weight: 800; color: var(--text); text-decoration: none; letter-spacing: -1px; font-family: 'Outfit', sans-serif; }
.nav-logo .logo-calc { color: var(--text); }
.nav-logo .logo-ivus { background: linear-gradient(135deg,#3B82F6,#06B6D4); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.nav-links { display: flex; gap: 4px; align-items: center; }
.nav-link { font-size: 13px; font-weight: 500; color: var(--text2); text-decoration: none; padding: 6px 12px; border-radius: 6px; transition: all .2s; }
.nav-link:hover { color: var(--text); background: var(--bg3); }
.nav-cta { font-size: 13px; font-weight: 600; color: white; background: var(--accent); border: none; border-radius: 6px; padding: 7px 16px; cursor: pointer; text-decoration: none; transition: background .2s; }
.nav-cta:hover { background: var(--accent-light); }
.nav-hamburger { display: none; background: none; border: none; color: var(--text2); font-size: 20px; cursor: pointer; padding: 6px; }
.mobile-nav { display: none; position: fixed; top: 60px; left: 0; right: 0; background: var(--bg2); border-bottom: 1px solid var(--border2); padding: 16px; z-index: 99; flex-direction: column; gap: 4px; }
.mobile-nav.open { display: flex; }
.mobile-nav a { color: var(--text2); text-decoration: none; padding: 10px 14px; border-radius: var(--radius); font-size: 14px; transition: background .15s; }
.mobile-nav a:hover { background: var(--bg3); color: var(--text); }

/* BREADCRUMB */
.breadcrumb { display: flex; align-items: center; gap: 6px; font-size: 12px; color: var(--text3); padding: 16px 0 0; flex-wrap: wrap; }
.breadcrumb a { color: var(--text3); text-decoration: none; transition: color .15s; }
.breadcrumb a:hover { color: var(--text2); }
.breadcrumb-sep { color: var(--border); }

/* CONTAINER */
.container { max-width: 1180px; margin: 0 auto; padding: 0 24px; }
.container-sm { max-width: 760px; margin: 0 auto; padding: 0 24px; }
.section { padding: 48px 0; }

/* CALCULATOR TOOL */
.calc-wrap { background: var(--bg2); border: 1px solid var(--border2); border-radius: var(--radius-lg); overflow: hidden; margin-bottom: 32px; }
.calc-head { padding: 20px 24px; border-bottom: 1px solid var(--border2); display: flex; align-items: center; gap: 12px; }
.calc-head-icon { width: 40px; height: 40px; border-radius: 10px; display: flex; align-items: center; justify-content: center; font-size: 20px; }
.calc-head-title { font-size: 18px; font-weight: 700; color: var(--text); }
.calc-head-cat { font-size: 12px; color: var(--text3); margin-top: 2px; }
.calc-body { padding: 24px; }
.calc-inputs { display: flex; flex-direction: column; gap: 14px; margin-bottom: 20px; }
.input-group { display: flex; flex-direction: column; gap: 6px; }
.input-label { font-size: 12px; font-weight: 600; color: var(--text2); letter-spacing: 0.04em; text-transform: uppercase; }
.calc-input { width: 100%; height: 46px; background: var(--bg3); border: 1px solid var(--border); border-radius: var(--radius); color: var(--text); font-family: 'JetBrains Mono', monospace; font-size: 15px; padding: 0 14px; outline: none; transition: border-color .2s; }
.calc-input:focus { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-glow); }
.calc-select { width: 100%; height: 46px; background: var(--bg3); border: 1px solid var(--border); border-radius: var(--radius); color: var(--text); font-family: 'Outfit', sans-serif; font-size: 14px; padding: 0 14px; outline: none; cursor: pointer; -webkit-appearance: none; }
.input-row { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.calc-btn { width: 100%; height: 50px; background: var(--accent); border: none; border-radius: var(--radius); color: white; font-family: 'Outfit', sans-serif; font-size: 15px; font-weight: 600; cursor: pointer; transition: background .2s; letter-spacing: 0.02em; }
.calc-btn:hover { background: var(--accent-light); }
.result-box { background: var(--bg3); border: 1px solid var(--border2); border-radius: var(--radius); padding: 20px; margin-top: 20px; display: none; }
.result-box.show { display: block; animation: fadeIn .3s ease; }
@keyframes fadeIn { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: translateY(0); } }
.result-label { font-size: 11px; font-weight: 600; color: var(--text3); text-transform: uppercase; letter-spacing: 0.06em; margin-bottom: 8px; }
.result-value { font-family: 'JetBrains Mono', monospace; font-size: 28px; font-weight: 500; color: var(--green); letter-spacing: -0.5px; word-break: break-all; }
.result-sub { font-size: 13px; color: var(--text2); margin-top: 8px; }
.result-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; margin-top: 12px; }
.result-item { background: var(--bg2); border-radius: 8px; padding: 12px; }
.result-item-label { font-size: 11px; color: var(--text3); margin-bottom: 4px; }
.result-item-value { font-family: 'JetBrains Mono', monospace; font-size: 15px; font-weight: 500; color: var(--text); }
.copy-btn { margin-top: 14px; background: var(--bg2); border: 1px solid var(--border2); border-radius: 6px; color: var(--text2); font-family: 'Outfit', sans-serif; font-size: 12px; font-weight: 500; padding: 6px 14px; cursor: pointer; transition: all .15s; }
.copy-btn:hover { color: var(--text); border-color: var(--border); }

/* FORMULA BOX */
.formula-box { background: var(--bg3); border: 1px solid var(--border2); border-radius: var(--radius); padding: 16px; margin-top: 20px; }
.formula-title { font-size: 12px; font-weight: 600; color: var(--text3); text-transform: uppercase; letter-spacing: 0.06em; margin-bottom: 8px; }
.formula-text { font-family: 'JetBrains Mono', monospace; font-size: 15px; color: var(--accent-light); letter-spacing: 0.02em; }
.formula-desc { font-size: 12px; color: var(--text2); margin-top: 8px; line-height: 1.6; }

/* CONTENT SECTIONS */
.content-section { margin-top: 40px; padding-top: 32px; border-top: 1px solid var(--border2); }
.content-section h2 { font-size: 20px; font-weight: 700; color: var(--text); margin-bottom: 14px; letter-spacing: -0.3px; }
.content-section p { font-size: 15px; color: var(--text2); line-height: 1.8; margin-bottom: 14px; }
.content-section ol, .content-section ul { margin: 10px 0 14px 20px; display: flex; flex-direction: column; gap: 8px; }
.content-section li { font-size: 14px; color: var(--text2); line-height: 1.7; }

/* FAQ */
.faq-list { display: flex; flex-direction: column; gap: 8px; margin-top: 12px; }
.faq-item { background: var(--bg3); border: 1px solid var(--border2); border-radius: var(--radius); overflow: hidden; }
.faq-q { font-size: 14px; font-weight: 600; color: var(--text); padding: 14px 16px; cursor: pointer; display: flex; justify-content: space-between; align-items: center; user-select: none; }
.faq-q:hover { background: var(--bg2); }
.faq-toggle { color: var(--text3); font-size: 18px; transition: transform .2s; }
.faq-item.open .faq-toggle { transform: rotate(45deg); }
.faq-a { font-size: 13px; color: var(--text2); line-height: 1.7; padding: 0 16px; max-height: 0; overflow: hidden; transition: max-height .3s ease, padding .3s ease; }
.faq-item.open .faq-a { max-height: 300px; padding: 0 16px 14px; }

/* RELATED CALCULATORS */
.related-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 10px; margin-top: 12px; }
.related-card { background: var(--bg2); border: 1px solid var(--border2); border-radius: var(--radius); padding: 14px 16px; text-decoration: none; display: flex; align-items: center; gap: 10px; transition: all .15s; }
.related-card:hover { border-color: var(--border); background: var(--bg3); transform: translateY(-1px); }
.related-icon { font-size: 20px; }
.related-name { font-size: 13px; font-weight: 600; color: var(--text); }
.related-cat { font-size: 11px; color: var(--text3); margin-top: 1px; }

/* HERO */
.page-hero { padding: 48px 0 32px; }
.page-hero h1 { font-size: clamp(28px,5vw,44px); font-weight: 700; letter-spacing: -1px; line-height: 1.15; margin-bottom: 12px; }
.page-hero h1 em { font-style: normal; background: linear-gradient(135deg,#3B82F6,#06B6D4); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.page-hero p { font-size: 16px; color: var(--text2); max-width: 580px; line-height: 1.7; }

/* CARDS */
.cards-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px,1fr)); gap: 14px; }
.card { background: var(--bg2); border: 1px solid var(--border2); border-radius: var(--radius-lg); padding: 20px; transition: all .2s; text-decoration: none; display: block; }
.card:hover { border-color: var(--border); transform: translateY(-2px); box-shadow: 0 8px 24px rgba(0,0,0,.3); }

/* BADGE */
.badge { display: inline-flex; align-items: center; gap: 5px; font-size: 11px; font-weight: 600; letter-spacing: .05em; text-transform: uppercase; border-radius: 100px; padding: 3px 12px; }
.badge-blue { background: var(--accent-glow); color: var(--accent-light); border: 1px solid rgba(37,99,235,.3); }
.badge-green { background: rgba(63,185,80,.1); color: var(--green); }

/* FOOTER */
footer { background: var(--bg2); border-top: 1px solid var(--border2); padding: 48px 24px 32px; margin-top: 80px; }
.footer-inner { max-width: 1180px; margin: 0 auto; }
.footer-grid { display: grid; grid-template-columns: 2fr repeat(4,1fr); gap: 32px; margin-bottom: 40px; }
.footer-brand .brand-name { font-size: 20px; font-weight: 800; letter-spacing: -0.5px; margin-bottom: 8px; }
.footer-brand .brand-name span { background: linear-gradient(135deg,#3B82F6,#06B6D4); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.footer-brand p { font-size: 13px; color: var(--text3); line-height: 1.6; }
.footer-col h4 { font-size: 12px; font-weight: 700; color: var(--text2); text-transform: uppercase; letter-spacing: .06em; margin-bottom: 12px; }
.footer-col ul { list-style: none; display: flex; flex-direction: column; gap: 7px; }
.footer-col a { font-size: 13px; color: var(--text3); text-decoration: none; transition: color .15s; }
.footer-col a:hover { color: var(--text2); }
.footer-bottom { border-top: 1px solid var(--border2); padding-top: 20px; display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 8px; }
.footer-bottom p { font-size: 12px; color: var(--text3); }

/* TOAST */
.toast { position: fixed; bottom: 24px; right: 24px; z-index: 500; background: var(--bg2); border: 1px solid var(--border); border-radius: var(--radius); padding: 12px 20px; font-size: 13px; font-weight: 500; color: var(--text); box-shadow: 0 8px 24px rgba(0,0,0,.4); transform: translateY(100px); opacity: 0; transition: all .3s ease; pointer-events: none; }
.toast.show { transform: translateY(0); opacity: 1; }

/* UTILS */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }
::selection { background: var(--accent-glow); color: var(--text); }

/* RESPONSIVE */
@media (max-width: 768px) {
  nav { padding: 0 16px; }
  .nav-links { display: none; }
  .nav-hamburger { display: block; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .footer-brand { grid-column: 1/-1; }
  .input-row { grid-template-columns: 1fr; }
  .result-grid { grid-template-columns: 1fr; }
  .page-hero { padding: 32px 0 24px; }
  .section { padding: 32px 0; }
}
@media (max-width: 480px) {
  .cards-grid { grid-template-columns: 1fr; }
  .related-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
}