:root {
  --bg: #0b1218; --surface: #182235; --surface-soft: #111b28;
  --border: #314158; --text: #eff4fb; --muted: #93a1b2;
  --accent: #16d6b2; --accent-dark: #06231d;
  --error: #ff7b7b; --warning: #f8c15c;
  --radius-lg: 18px; --radius-md: 12px;
  color-scheme: dark;
}

* { box-sizing: border-box; }
html { min-width: 320px; background: var(--bg); }
body { margin: 0; color: var(--text); background: var(--bg); font: 16px/1.55 -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; }
a { color: inherit; text-decoration: none; }
button, input { font: inherit; }
.content-width, .nav-inner, .site-footer { width: min(calc(100% - 32px), 1040px); margin-inline: auto; }

.site-nav { border-bottom: 1px solid rgba(147, 161, 178, .22); background: rgba(11, 18, 24, .92); }
.nav-inner { min-height: 64px; display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.brand { font-size: 20px; font-weight: 800; letter-spacing: .04em; }
.nav-label { color: var(--muted); font-size: 13px; }

.tool-header { padding: 32px 0 22px; border-bottom: 1px solid rgba(147, 161, 178, .14); }
.eyebrow { margin: 0 0 8px; color: var(--accent); font-size: 14px; font-weight: 750; letter-spacing: .08em; }
h1 { margin: 0; font-size: clamp(30px, 8vw, 44px); line-height: 1.15; letter-spacing: -.03em; }
.tool-description { max-width: 620px; margin: 12px 0 0; color: var(--muted); }

.calculator-layout { display: grid; gap: 18px; padding-block: 22px 44px; }
.panel { min-width: 0; padding: 20px; border: 1px solid var(--border); border-radius: var(--radius-lg); background: var(--surface); }
.panel-heading { display: flex; align-items: flex-start; gap: 12px; padding-bottom: 18px; border-bottom: 1px solid rgba(147, 161, 178, .16); }
.panel-heading h2 { margin: 0; font-size: 20px; }
.panel-heading p { margin: 3px 0 0; color: var(--muted); font-size: 13px; }
.step { display: grid; place-items: center; width: 34px; height: 34px; flex: 0 0 auto; border-radius: 10px; color: var(--accent); background: rgba(22, 214, 178, .11); font-size: 12px; font-weight: 800; }

.form-group { margin-top: 20px; }
.form-group label { display: block; margin-bottom: 8px; font-weight: 700; }
.input-shell { display: grid; grid-template-columns: minmax(0, 1fr) auto; overflow: hidden; border: 1px solid var(--border); border-radius: var(--radius-md); background: var(--surface-soft); }
.input-shell:focus-within { border-color: var(--accent); box-shadow: 0 0 0 3px rgba(22, 214, 178, .12); }
.input-shell input { width: 100%; min-width: 0; min-height: 50px; border: 0; outline: 0; padding: 0 14px; color: var(--text); background: transparent; }
.input-unit { display: grid; place-items: center; min-width: 64px; padding: 0 13px; border-left: 1px solid rgba(147, 161, 178, .16); color: var(--muted); }
.field-help, .field-error { margin: 7px 2px 0; font-size: 13px; }
.field-help { color: var(--muted); }
.field-error { color: var(--error); }
.has-error .input-shell { border-color: var(--error); }

.primary-button { width: 100%; min-height: 50px; margin-top: 24px; border: 0; border-radius: var(--radius-md); padding: 0 18px; color: var(--accent-dark); background: var(--accent); font-weight: 800; cursor: pointer; }
.primary-button:focus-visible { outline: 3px solid rgba(22, 214, 178, .35); outline-offset: 3px; }

.primary-result { margin-top: 20px; padding: 20px; border-radius: 14px; background: var(--surface-soft); }
.primary-result span, .metric span { display: block; color: var(--muted); font-size: 13px; }
.primary-result strong { display: inline-block; margin-top: 4px; color: var(--accent); font-size: clamp(34px, 10vw, 48px); line-height: 1.1; letter-spacing: -.04em; }
.primary-result small { margin-left: 5px; color: var(--muted); font-size: 15px; }
.secondary-results { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px; margin-top: 10px; }
.metric { min-width: 0; padding: 14px; border: 1px solid var(--border); border-radius: 12px; }
.metric strong { display: block; overflow-wrap: anywhere; margin-top: 4px; font-size: 18px; }
.metric small { color: var(--muted); }
.result-empty { min-height: 205px; display: grid; place-content: center; justify-items: center; text-align: center; color: var(--muted); }
.result-empty span { display: grid; place-items: center; width: 52px; height: 52px; border: 1px solid var(--border); border-radius: 16px; color: var(--accent); font-size: 30px; }
.result-empty p { max-width: 230px; margin: 12px 0 0; }

.alert { display: flex; align-items: flex-start; gap: 8px; margin-top: 16px; padding: 12px 14px; border-radius: 10px; font-size: 13px; }
.alert strong { flex: 0 0 auto; }
.alert-error { color: var(--error); background: rgba(255, 123, 123, .08); border: 1px solid rgba(255, 123, 123, .25); }
.alert-warning { color: var(--warning); background: rgba(248, 193, 92, .08); border: 1px solid rgba(248, 193, 92, .25); }
.calculation-notes { margin-top: 20px; padding-top: 18px; border-top: 1px solid rgba(147, 161, 178, .16); color: var(--muted); font-size: 13px; }
.notes-title { display: flex; align-items: baseline; justify-content: space-between; gap: 10px; }
.calculation-notes h3 { margin: 0; color: var(--text); font-size: 15px; }
.calculation-notes ul { margin: 10px 0 18px; padding-left: 19px; }
.calculation-notes p { margin: 8px 0 0; }
.site-footer { padding-block: 22px 34px; border-top: 1px solid rgba(147, 161, 178, .14); color: var(--muted); font-size: 12px; }

.home-hero { padding: 42px 0 30px; border-bottom: 1px solid rgba(147, 161, 178, .14); background: radial-gradient(circle at 75% 10%, rgba(22, 214, 178, .08), transparent 38%); }
.home-hero h1 { max-width: 680px; }
.hero-description { max-width: 620px; margin: 12px 0 0; color: var(--muted); }
.tool-search { display: grid; grid-template-columns: auto minmax(0, 1fr) auto; max-width: 720px; min-height: 54px; margin-top: 24px; overflow: hidden; border: 1px solid var(--border); border-radius: 14px; background: var(--surface); }
.tool-search:focus-within { border-color: var(--accent); box-shadow: 0 0 0 3px rgba(22, 214, 178, .12); }
.search-symbol { display: grid; place-items: center; padding-left: 16px; color: var(--muted); font-size: 23px; }
.tool-search input { width: 100%; min-width: 0; border: 0; outline: 0; padding: 0 12px; color: var(--text); background: transparent; }
.tool-search button { border: 0; padding: 0 20px; color: var(--accent-dark); background: var(--accent); font-weight: 800; cursor: pointer; }
.hero-meta { display: flex; flex-wrap: wrap; gap: 10px 18px; margin-top: 18px; color: var(--muted); font-size: 13px; }
.hero-meta strong { color: var(--text); }
.home-content { min-height: 340px; padding-block: 30px 48px; }
.catalog-heading, .category-heading { display: flex; align-items: flex-end; justify-content: space-between; gap: 16px; }
.catalog-heading h2 { margin: 0; font-size: 25px; }
.search-summary, .category-heading span { color: var(--muted); font-size: 13px; }
.search-summary a { color: var(--accent); }
.tool-category { margin-top: 26px; }
.category-heading { padding-bottom: 10px; border-bottom: 1px solid rgba(147, 161, 178, .16); }
.category-heading h3 { margin: 0; font-size: 18px; }
.tool-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(100%, 240px), 1fr)); gap: 12px; margin-top: 12px; }
.tool-card { display: block; min-width: 0; padding: 18px; border: 1px solid var(--border); border-radius: 15px; background: var(--surface); }
.tool-card:hover { border-color: rgba(22, 214, 178, .55); }
.tool-card:focus-visible { outline: 3px solid rgba(22, 214, 178, .3); outline-offset: 3px; }
.tool-card-top { display: flex; justify-content: space-between; gap: 12px; margin-bottom: 18px; }
.tool-badge { color: var(--accent); font-size: 12px; font-weight: 750; }
.tool-arrow { color: var(--muted); }
.tool-card strong { display: block; font-size: 19px; }
.tool-card p { margin: 6px 0 0; color: var(--muted); font-size: 13px; }
.no-results { padding: 54px 18px; text-align: center; color: var(--muted); }
.no-results > span { display: grid; place-items: center; width: 54px; height: 54px; margin: 0 auto; border: 1px solid var(--border); border-radius: 16px; color: var(--accent); font-size: 28px; }
.no-results h3 { margin: 14px 0 4px; color: var(--text); }
.no-results p { margin: 0; }
.secondary-button { display: inline-flex; min-height: 42px; align-items: center; margin-top: 18px; border: 1px solid var(--border); border-radius: 10px; padding: 0 16px; color: var(--text); }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; }

@media (min-width: 800px) {
  .content-width, .nav-inner, .site-footer { width: min(calc(100% - 48px), 1040px); }
  .tool-header { padding: 46px 0 28px; }
  .home-hero { padding: 58px 0 38px; }
  .calculator-layout { grid-template-columns: minmax(0, .9fr) minmax(0, 1.1fr); align-items: start; padding-top: 28px; }
  .panel { padding: 24px; }
}