:root {
  color-scheme: light;
  --ink: #f4f4f1;
  --muted: #a2a29d;
  --line: #2d2d2a;
  --paper: #070807;
  --card: #111210;
  --accent: #b8ed25;
  --accent-strong: #9bd20f;
  --shadow: 0 24px 70px rgba(0, 0, 0, .35);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  color: var(--ink);
  background:
    radial-gradient(circle at 85% 4%, rgba(184, 237, 37, .14), transparent 28rem),
    var(--paper);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

.page-shell {
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
  padding: 72px 0;
}

.brand { display: flex; align-items: center; margin-bottom: 68px; }
.brand-logo { display: block; width: 156px; height: auto; }

.intro { max-width: 760px; margin-bottom: 38px; }
.eyebrow { font-size: .75rem; font-weight: 700; letter-spacing: .16em; }
h1 { margin: 12px 0 16px; font-size: clamp(2.4rem, 6vw, 5rem); line-height: .98; letter-spacing: -.055em; }
.intro p { max-width: 650px; margin: 0; color: var(--muted); font-size: 1.08rem; line-height: 1.6; }

.calculator {
  display: grid;
  grid-template-columns: minmax(280px, .82fr) minmax(420px, 1.18fr);
  gap: 18px;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 28px;
  background: rgba(17,18,16,.78);
  box-shadow: var(--shadow);
  backdrop-filter: blur(12px);
}

.inputs { display: grid; gap: 18px; padding: 22px; }
.field { display: grid; gap: 8px; }
label { font-size: .88rem; font-weight: 650; }
input {
  width: 100%; border: 1px solid var(--line); border-radius: 12px; background: var(--card);
  color: var(--ink); padding: 14px 15px; font: inherit; font-size: 1.05rem; outline: none;
  transition: border-color .2s, box-shadow .2s;
}
input:focus { border-color: var(--accent); box-shadow: 0 0 0 4px rgba(184,237,37,.10); }
input[type="number"] { appearance: textfield; -moz-appearance: textfield; }
input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button { appearance: none; -webkit-appearance: none; margin: 0; }
.input-affix { display: flex; align-items: center; border: 1px solid var(--line); border-radius: 12px; background: var(--card); overflow: hidden; }
.input-affix:focus-within { border-color: var(--accent); box-shadow: 0 0 0 4px rgba(184,237,37,.10); }
.input-affix input { border: 0; border-radius: 0; box-shadow: none; }
.input-affix span { padding: 0 15px; color: var(--muted); font-weight: 650; }
.input-affix:not(.prefix) span { border-left: 1px solid var(--line); }
.prefix span { border-right: 1px solid var(--line); }

.results { border-radius: 20px; background: #020302; color: var(--ink); padding: 26px; border: 1px solid #242522; }
.result-card { display: grid; gap: 7px; }
.result-label { color: #bdbdb6; font-size: .8rem; letter-spacing: .02em; }
.result-card strong { font-size: clamp(1.35rem, 3vw, 2rem); letter-spacing: -.04em; }
.hero-result { padding: 24px; border-radius: 16px; background: var(--accent); color: #11130b; }
.hero-result .result-label, .hero-result span:last-child { color: #3f481f; }
.hero-result strong { font-size: clamp(3rem, 7vw, 5.4rem); line-height: 1; }
.hero-result span:last-child { font-size: .86rem; }
.result-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 28px 18px; padding: 28px 6px 20px; }
.formula { margin: 0; padding: 18px 6px 2px; border-top: 1px solid #343432; color: #bdbdb6; font-size: .88rem; line-height: 1.5; }

@media (max-width: 780px) {
  .page-shell { padding: 42px 0; }
  .calculator { grid-template-columns: 1fr; }
  .inputs { padding: 14px 8px; }
}

@media (max-width: 460px) {
  .page-shell { width: min(100% - 20px, 1120px); padding: 30px 0; }
  .calculator { padding: 10px; border-radius: 20px; }
  .results { padding: 16px; }
  .result-grid { grid-template-columns: 1fr; gap: 20px; }
}