:root {
  --bg: #08111f;
  --surface: #0f1b2d;
  --surface-2: #142238;
  --line: rgba(255,255,255,.08);
  --text: #f7f9fc;
  --muted: #96a4b8;
  --accent: #7cf2c8;
  --accent-2: #7fb4ff;
  --danger: #ff8c8c;
  --shadow: 0 24px 80px rgba(0,0,0,.28);
  --radius-lg: 28px;
  --radius-md: 18px;
  --radius-sm: 12px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  min-height: 100vh;
  font-family: Inter, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at 15% -10%, rgba(127,180,255,.16), transparent 34rem),
    radial-gradient(circle at 90% 14%, rgba(124,242,200,.10), transparent 28rem),
    var(--bg);
}
button, input { font: inherit; }
button { cursor: pointer; }
a { color: inherit; text-decoration: none; }

.topbar {
  width: min(1180px, calc(100% - 40px));
  margin: 0 auto;
  min-height: 76px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--line);
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
  letter-spacing: -.02em;
}
.brand strong { color: var(--accent); }
.brand-mark {
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  border-radius: 10px;
  color: #071018;
  background: linear-gradient(135deg, var(--accent), #b8ffe6);
  font-weight: 800;
}
.github-link {
  color: var(--muted);
  font-size: 14px;
}
.github-link:hover { color: var(--text); }

main { width: min(1180px, calc(100% - 40px)); margin: 0 auto; }
.hero {
  padding: 88px 0 62px;
  max-width: 860px;
}
.eyebrow, .section-kicker {
  color: var(--accent);
  font-size: 12px;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: .14em;
}
.hero h1 {
  margin: 15px 0 20px;
  max-width: 760px;
  font-size: clamp(52px, 8vw, 92px);
  line-height: .92;
  letter-spacing: -.065em;
}
.hero h1 span {
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero > p {
  margin: 0;
  max-width: 650px;
  color: var(--muted);
  font-size: clamp(17px, 2vw, 21px);
  line-height: 1.65;
}
.search {
  margin-top: 36px;
  max-width: 760px;
  min-height: 66px;
  padding: 0 20px;
  display: flex;
  align-items: center;
  gap: 12px;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: rgba(255,255,255,.055);
  box-shadow: var(--shadow);
  backdrop-filter: blur(14px);
}
.search:focus-within {
  border-color: rgba(124,242,200,.48);
  box-shadow: 0 0 0 4px rgba(124,242,200,.08), var(--shadow);
}
.search span { font-size: 30px; color: var(--accent); transform: translateY(-1px); }
.search input {
  width: 100%;
  border: 0;
  outline: 0;
  background: transparent;
  color: var(--text);
  font-size: 16px;
}
.search input::placeholder { color: #74849a; }
.quick-links {
  margin-top: 17px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
  color: var(--muted);
  font-size: 13px;
}
.quick-links button {
  padding: 7px 10px;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: #c9d5e5;
  background: transparent;
}
.quick-links button:hover { border-color: rgba(124,242,200,.32); color: var(--accent); }

.workspace {
  display: grid;
  grid-template-columns: 380px minmax(0,1fr);
  gap: 22px;
  align-items: start;
  padding: 28px 0 90px;
}
.catalog, .calculator-panel {
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: rgba(15,27,45,.76);
  box-shadow: var(--shadow);
  backdrop-filter: blur(16px);
}
.catalog { padding: 22px; }
.catalog-heading {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 18px;
  margin-bottom: 18px;
}
.catalog-heading h2 {
  margin: 6px 0 0;
  font-size: 21px;
  letter-spacing: -.03em;
}
.count {
  min-width: 32px;
  height: 32px;
  display: grid;
  place-items: center;
  border-radius: 999px;
  background: rgba(124,242,200,.12);
  color: var(--accent);
  font-size: 13px;
  font-weight: 700;
}
.calculator-list { display: grid; gap: 8px; }
.calculator-card {
  width: 100%;
  padding: 14px;
  display: grid;
  grid-template-columns: 40px 1fr auto;
  gap: 12px;
  align-items: center;
  border: 1px solid transparent;
  border-radius: 14px;
  text-align: left;
  color: var(--text);
  background: transparent;
  transition: .18s ease;
}
.calculator-card:hover {
  background: rgba(255,255,255,.04);
  border-color: var(--line);
}
.calculator-card.active {
  background: linear-gradient(90deg, rgba(124,242,200,.10), rgba(127,180,255,.06));
  border-color: rgba(124,242,200,.22);
}
.card-icon {
  width: 40px;
  height: 40px;
  display: grid;
  place-items: center;
  border-radius: 12px;
  background: rgba(255,255,255,.06);
  font-size: 18px;
}
.card-copy strong { display: block; font-size: 14px; }
.card-copy small { display: block; margin-top: 3px; color: var(--muted); font-size: 11px; }
.card-arrow { color: #6e7e93; }
.empty-state { padding: 26px 10px; color: var(--muted); text-align: center; line-height: 1.6; }

.calculator-panel {
  min-height: 550px;
  padding: clamp(24px, 4vw, 42px);
}
.panel-head {
  display: flex;
  justify-content: space-between;
  gap: 24px;
  align-items: flex-start;
  padding-bottom: 26px;
  border-bottom: 1px solid var(--line);
}
.panel-title-wrap { display: flex; gap: 15px; align-items: flex-start; }
.panel-icon {
  width: 54px;
  height: 54px;
  flex: 0 0 54px;
  display: grid;
  place-items: center;
  border-radius: 16px;
  background: linear-gradient(145deg, rgba(124,242,200,.18), rgba(127,180,255,.10));
  font-size: 25px;
}
.panel-head h2 { margin: 2px 0 7px; font-size: clamp(25px, 3vw, 34px); letter-spacing: -.045em; }
.panel-head p { margin: 0; color: var(--muted); line-height: 1.55; max-width: 540px; }
.category-pill {
  padding: 7px 10px;
  white-space: nowrap;
  border-radius: 999px;
  background: rgba(255,255,255,.05);
  color: var(--muted);
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .08em;
}
.calc-form { padding-top: 26px; }
.fields-grid { display: grid; grid-template-columns: repeat(2, minmax(0,1fr)); gap: 14px; }
.field { display: grid; gap: 7px; }
.field.full { grid-column: 1 / -1; }
.field label { color: #c6d1df; font-size: 12px; font-weight: 600; }
.field-shell {
  min-height: 52px;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 0 13px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: rgba(4,10,18,.35);
}
.field-shell:focus-within { border-color: rgba(124,242,200,.42); box-shadow: 0 0 0 3px rgba(124,242,200,.06); }
.field-shell span { color: var(--muted); font-size: 13px; white-space: nowrap; }
.field-shell input {
  width: 100%;
  min-width: 0;
  border: 0;
  outline: 0;
  color: var(--text);
  background: transparent;
}
.field-shell input::-webkit-inner-spin-button { opacity: .4; }
.calc-actions { margin-top: 18px; display: flex; gap: 10px; }
.primary-btn, .secondary-btn {
  min-height: 50px;
  padding: 0 18px;
  border-radius: 12px;
  font-weight: 800;
  border: 0;
}
.primary-btn {
  color: #07120f;
  background: linear-gradient(135deg, var(--accent), #b6ffe5);
}
.primary-btn:hover { filter: brightness(1.04); transform: translateY(-1px); }
.secondary-btn { color: var(--muted); background: rgba(255,255,255,.05); }
.secondary-btn:hover { color: var(--text); }

.result-box {
  margin-top: 28px;
  padding: 22px;
  border: 1px solid rgba(124,242,200,.16);
  border-radius: 18px;
  background: linear-gradient(135deg, rgba(124,242,200,.08), rgba(127,180,255,.05));
}
.result-label { color: var(--muted); font-size: 12px; text-transform: uppercase; font-weight: 800; letter-spacing: .10em; }
.result-main { margin-top: 7px; font-size: clamp(34px, 5vw, 54px); font-weight: 800; letter-spacing: -.055em; color: var(--accent); }
.result-subtitle { margin-top: 5px; color: #c4d0df; line-height: 1.5; }
.metrics {
  margin-top: 20px;
  display: grid;
  grid-template-columns: repeat(3, minmax(0,1fr));
  gap: 10px;
}
.metric {
  padding: 13px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: rgba(0,0,0,.12);
}
.metric span { display: block; color: var(--muted); font-size: 11px; }
.metric strong { display: block; margin-top: 5px; font-size: 15px; }
.formula-note {
  margin-top: 15px;
  color: var(--muted);
  font-size: 11px;
  line-height: 1.55;
}
.error-message {
  margin-top: 18px;
  padding: 13px 14px;
  border: 1px solid rgba(255,140,140,.22);
  border-radius: 12px;
  color: #ffc2c2;
  background: rgba(255,140,140,.07);
  font-size: 13px;
}

.decision-section {
  padding: 28px 0 90px;
  border-top: 1px solid var(--line);
}
.decision-section > div:first-child {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 30px;
}
.decision-section h2 {
  margin: 8px 0 0;
  max-width: 700px;
  font-size: clamp(30px, 5vw, 52px);
  letter-spacing: -.05em;
}
.decision-grid {
  margin-top: 30px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
}
.decision-grid article {
  min-height: 190px;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: 20px;
  background: rgba(255,255,255,.025);
}
.decision-grid article > span { color: var(--accent); font-size: 11px; font-weight: 800; }
.decision-grid h3 { margin: 35px 0 9px; font-size: 20px; letter-spacing: -.03em; }
.decision-grid p { margin: 0; color: var(--muted); font-size: 13px; line-height: 1.6; }

footer {
  width: min(1180px, calc(100% - 40px));
  margin: 0 auto;
  padding: 28px 0 45px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 12px;
  line-height: 1.6;
}

@media (max-width: 900px) {
  .workspace { grid-template-columns: 1fr; }
  .catalog { order: 1; }
  .calculator-panel { order: 2; }
  .calculator-list { grid-template-columns: repeat(2, minmax(0,1fr)); }
  .decision-grid { grid-template-columns: 1fr; }
  .decision-grid article { min-height: 150px; }
  .decision-grid h3 { margin-top: 22px; }
}

@media (max-width: 620px) {
  .topbar, main, footer { width: min(100% - 24px, 1180px); }
  .topbar { min-height: 64px; }
  .brand { font-size: 14px; }
  .github-link { font-size: 12px; }
  .hero { padding: 58px 0 42px; }
  .hero h1 { font-size: clamp(48px, 17vw, 70px); }
  .search { min-height: 58px; padding: 0 14px; }
  .quick-links span { width: 100%; }
  .workspace { padding-top: 10px; }
  .catalog, .calculator-panel { border-radius: 21px; }
  .catalog { padding: 15px; }
  .calculator-list { grid-template-columns: 1fr; }
  .calculator-card { padding: 12px; }
  .panel-head { display: block; }
  .category-pill { display: inline-block; margin: 17px 0 0 69px; }
  .fields-grid { grid-template-columns: 1fr; }
  .field.full { grid-column: auto; }
  .metrics { grid-template-columns: 1fr; }
  .decision-section { padding-bottom: 60px; }
}