* { box-sizing: border-box; }

:root {
  --ink: #202124;
  --muted: #6b7280;
  --line: #e7e7e7;
  --bg: #fafaf8;
  --card: #ffffff;
  --accent: #ff7a59;
  --accent-dark: #e85f3e;
  --soft: #fff1ec;
}

body {
  margin: 0;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--ink);
  background: var(--bg);
}

.topbar {
  max-width: 1100px;
  margin: auto;
  padding: 22px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  font-size: 24px;
  font-weight: 800;
  letter-spacing: -0.6px;
}

.bunny { margin-right: 7px; }
.tagline { color: var(--muted); font-size: 14px; }

main {
  max-width: 1100px;
  margin: auto;
  padding: 35px 24px 80px;
}

.hero {
  text-align: center;
  padding: 45px 0 42px;
}

.hero-bunny {
  font-size: 54px;
  margin-bottom: 14px;
}

h1 {
  margin: 0;
  font-size: clamp(32px, 5vw, 52px);
  line-height: 1.05;
  letter-spacing: -2px;
}

.hero p {
  color: var(--muted);
  font-size: 18px;
  margin: 18px auto 0;
  max-width: 560px;
}

.calculator-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}

.calc-card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 23px;
  cursor: pointer;
  transition: transform .15s ease, box-shadow .15s ease, border-color .15s ease;
}

.calc-card:hover {
  transform: translateY(-2px);
  border-color: #d8d8d8;
  box-shadow: 0 8px 25px rgba(0,0,0,.06);
}

.calc-icon { font-size: 28px; }
.calc-card h2 { font-size: 19px; margin: 12px 0 7px; }
.calc-card p { color: var(--muted); margin: 0; line-height: 1.45; font-size: 14px; }

.calculator-panel {
  max-width: 720px;
  margin: 20px auto 0;
}

.hidden { display: none !important; }

.back-button {
  border: 0;
  background: transparent;
  padding: 8px 0;
  color: var(--muted);
  cursor: pointer;
  font-size: 14px;
  margin-bottom: 18px;
}

.calc-box {
  background: white;
  border: 1px solid var(--line);
  border-radius: 22px;
  padding: 30px;
}

.calc-title {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 8px;
}

.calc-title .icon { font-size: 32px; }
.calc-box h2 { margin: 0; font-size: 28px; letter-spacing: -.8px; }
.calc-box .intro { color: var(--muted); margin: 5px 0 25px; }

.fields {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.field label {
  display: block;
  font-size: 13px;
  font-weight: 650;
  margin-bottom: 7px;
}

.field input {
  width: 100%;
  border: 1px solid #d8d8d8;
  border-radius: 11px;
  padding: 12px 13px;
  font-size: 16px;
  outline: none;
  background: #fff;
}

.field input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(255,122,89,.12);
}

.full { grid-column: 1 / -1; }

.calculate {
  width: 100%;
  margin-top: 22px;
  border: 0;
  border-radius: 12px;
  padding: 14px 18px;
  background: var(--accent);
  color: white;
  font-weight: 750;
  font-size: 16px;
  cursor: pointer;
}

.calculate:hover { background: var(--accent-dark); }

.result {
  margin-top: 22px;
  padding: 22px;
  border-radius: 15px;
  background: var(--soft);
}

.result-label { color: var(--muted); font-size: 13px; }
.result-value { font-size: 34px; font-weight: 850; letter-spacing: -1px; margin: 3px 0; }
.result-note { color: #555; font-size: 13px; line-height: 1.45; }

footer {
  max-width: 1100px;
  margin: auto;
  border-top: 1px solid var(--line);
  padding: 25px 24px 35px;
  display: flex;
  justify-content: space-between;
  color: var(--muted);
  font-size: 13px;
}

@media (max-width: 700px) {
  .topbar { padding: 18px; }
  .tagline { display: none; }
  main { padding: 20px 16px 60px; }
  .hero { padding: 35px 0; }
  .calculator-grid { grid-template-columns: 1fr; }
  .fields { grid-template-columns: 1fr; }
  .full { grid-column: auto; }
  .calc-box { padding: 22px; }
  footer { margin: 0 16px; padding-left: 0; padding-right: 0; }
}