:root {
  --primary: #0F6F68;
  --mint: #48C8A0;
  --bg: #F6F7F6;
  --surface: #FFFFFF;
  --text: #1F2623;
  --muted: #5A635E;
  --error: #B3261E;
  --radius: 10px;
  --space: 1rem;
}

* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: "Segoe UI", system-ui, sans-serif;
  background: linear-gradient(160deg, #e8f4f1 0%, var(--bg) 40%, #eef1ef 100%);
  color: var(--text);
  min-height: 100vh;
}
.top {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding: 1rem 1.25rem;
  border-bottom: 1px solid #d8e0dc;
  background: rgba(255,255,255,.7);
  backdrop-filter: blur(8px);
}
.brand {
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--primary);
  text-decoration: none;
}
.wrap { max-width: 40rem; margin: 0 auto; padding: 1.5rem 1.25rem 3rem; }
.hero h1 { margin: 0 0 .35rem; font-size: 1.75rem; letter-spacing: -0.02em; }
.lede { color: var(--muted); margin: 0 0 1.25rem; }
.card {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 1.25rem;
  box-shadow: 0 1px 0 rgba(15,111,104,.08);
  border: 1px solid #e2e8e5;
  margin-bottom: 1rem;
}
.stack { display: grid; gap: .85rem; }
.stack.mt { margin-top: 1rem; }
label { display: grid; gap: .35rem; font-size: .9rem; font-weight: 600; }
textarea {
  font: inherit;
  font-weight: 400;
  padding: .65rem .75rem;
  border: 1px solid #c9d2cd;
  border-radius: 8px;
  background: #fff;
  width: 100%;
  resize: vertical;
}
.btn {
  font: inherit;
  font-weight: 600;
  border: 0;
  border-radius: 8px;
  padding: .75rem 1rem;
  cursor: pointer;
}
.btn.primary { background: var(--primary); color: #fff; }
.btn.primary:hover { filter: brightness(1.05); }
.btn.ghost { background: transparent; color: var(--muted); border: 1px solid #c9d2cd; }
.flash {
  background: #e6f6ef;
  border: 1px solid var(--mint);
  color: var(--text);
  padding: .75rem 1rem;
  border-radius: 8px;
}
.errors { color: var(--error); }
.muted { color: var(--muted); font-weight: 400; font-size: .9rem; }
.result { display: grid; grid-template-columns: 8rem 1fr; gap: .5rem 1rem; margin: 0; }
.result dt { color: var(--muted); font-weight: 600; }
.result dd { margin: 0; }
.pre { white-space: pre-wrap; }
.foot {
  max-width: 40rem;
  margin: 0 auto;
  padding: 0 1.25rem 2rem;
  color: var(--muted);
  font-size: .85rem;
}
code { background: #eef3f1; padding: .1rem .35rem; border-radius: 4px; }