:root {
  color-scheme: light;
  --ink: #182321;
  --muted: #61706b;
  --paper: #f4f1e8;
  --card: #fffdf7;
  --line: #d8d4c8;
  --accent: #176b58;
  --accent-soft: #dcebe5;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  color: var(--ink);
  background:
    radial-gradient(circle at 12% 8%, #e2eee7 0, transparent 28rem),
    var(--paper);
  font: 16px/1.55 ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

.shell { width: min(920px, calc(100% - 32px)); margin: 0 auto; }

header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 24px 0;
  border-bottom: 1px solid var(--line);
}

.brand { color: var(--ink); font-weight: 760; text-decoration: none; letter-spacing: -.02em; }
.status { color: var(--muted); font-size: .85rem; }
.hero { padding: 72px 0 36px; max-width: 700px; }
.eyebrow { color: var(--accent); font-size: .78rem; font-weight: 800; letter-spacing: .14em; text-transform: uppercase; }
h1 { margin: 10px 0 16px; font-family: Georgia, serif; font-size: clamp(2.45rem, 7vw, 5rem); font-weight: 500; line-height: .98; letter-spacing: -.045em; }
.intro { color: var(--muted); max-width: 590px; font-size: 1.08rem; }

.converter {
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: 22px;
  background: color-mix(in srgb, var(--card) 92%, transparent);
  box-shadow: 0 24px 60px rgba(33, 54, 48, .08);
}

.tabs { display: flex; gap: 8px; margin-bottom: 24px; }
.tab, .swap { border: 0; cursor: pointer; font: inherit; }
.tab { padding: 9px 14px; border-radius: 999px; color: var(--muted); background: transparent; }
.tab.active { color: #fff; background: var(--accent); }
.grid { display: grid; grid-template-columns: 1.4fr 1fr auto 1fr; gap: 12px; align-items: end; }
label span { display: block; margin: 0 0 7px 2px; color: var(--muted); font-size: .8rem; font-weight: 700; text-transform: uppercase; letter-spacing: .07em; }
input, select { width: 100%; min-height: 50px; padding: 0 13px; border: 1px solid var(--line); border-radius: 12px; background: #fff; color: var(--ink); font: inherit; }
input:focus, select:focus { outline: 3px solid var(--accent-soft); border-color: var(--accent); }
.swap { width: 48px; height: 50px; border-radius: 12px; color: var(--accent); background: var(--accent-soft); font-size: 1.25rem; }
.result { display: flex; align-items: baseline; gap: 10px; margin-top: 28px; padding-top: 22px; border-top: 1px solid var(--line); }
.result span { font-family: Georgia, serif; font-size: clamp(2rem, 8vw, 4.3rem); line-height: 1; overflow-wrap: anywhere; }
.result small { color: var(--muted); }
.notes { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin: 18px 0 52px; }
.notes article { display: grid; gap: 5px; padding: 18px; border-top: 2px solid var(--accent); background: rgba(255,255,255,.42); }
.notes span, footer { color: var(--muted); font-size: .88rem; }
footer { padding: 24px 0 36px; border-top: 1px solid var(--line); }

@media (max-width: 680px) {
  .status { display: none; }
  .hero { padding-top: 48px; }
  .grid { grid-template-columns: 1fr 1fr; }
  .grid label:first-child { grid-column: 1 / -1; }
  .swap { display: none; }
  .notes { grid-template-columns: 1fr; }
}